CN106101703A - A kind of screen video compression method towards numeral KVM switcher - Google Patents

Abstract

The invention discloses a kind of screen video compression method towards numeral KVM switcher, comprise the following steps: (1) inputs frame screen video data；(2) frame originating point information of current video frame is write code stream；(3) from current video frame, a uncoded chromatic component subframe is obtained；(4) from current chroma component sub-frame, a uncoded data block is obtained；(5) calculate current block coding information under each candidate coding pattern and rebuild data, and choosing final coding mode；(6) the coding information of current block is write code stream；(7) step (4) to (6) is repeated；(8) to current video frame written into code stream carry out byte-aligned process；(9) step (3) to (8) is repeated；(10) code stream producing current video frame carries out frame synchronization head escape process.The present invention effectively reduces entirety and the peak-data amount of screen video code stream under limited computation complexity, keeps good reconstruction video quality simultaneously.

Description

A kind of screen video compression method towards numeral KVM switcher

Technical field

The present invention relates to digital video signal processing field, be specifically related to a kind of screen towards numeral KVM switcher and regard Frequently compression method.

Background technology

Numeral kvm system is the multicomputer handover management system of IP based network, it is possible to realize using a set of keyboard (Keyboard), display (Video), mouse (Mouse) remotely control multiple stage computer, mainly include numeral KVM switching Device and main control platform.The output signal of computer display is digitized and network transmission by numeral KVM switcher, in order to Display screen video in the client of main control platform.Additionally, numeral KVM switcher also receives the keyboard from main control platform and Mus Mark information, and it is converted into the input signal of local computer, to realize the main control platform long-range control to local computer. Keyboard and mouse are relatively low due to operation frequency, and the data volume after its signal is digitized into is the least, can be without compression directly biography Sending, the network bandwidth taken is less.Display is the highest due to resolution and the frame per second of the screen video of output, causes through numeral The video data volume after change is huge, it is impossible to directly transmit.Therefore, the screen of display output is only regarded by numeral KVM switcher Frequency compresses efficiently, could is real-time transmitted to long-range by network by screen video data under the limited network bandwidth Main control platform.The screen video scene of numeral KVM switcher collection mainly includes operating system scene, application software scene and net Page scenes etc., the resolution of screen video includes the typical resolution from 640 × 350 to 1920 × 1200.In computer system In, the display video of output use RGB color degree space, i.e. each pixel in image comprise a R component, a G component and One B component, each component generally represents with 8 bits, and span is 0～255.The screen video of numeral kvm system output Although abundant in content various, but there is the strongest temporal correlation, can use the method for video compress that it is compressed place Reason.There is again notable difference with the common natural video frequency of video camera shooting in the screen video of KVM simultaneously, and it comprises some by calculating The graph image that machine generates, the definition of these pictures is required the highest by people, it is easy to discover the loss of picture.Therefore, Numeral KVM switcher should carry out Efficient Compression to screen video, the most also to keep preferable video image quality.

Since the nineties in last century, International Telecommunication Union (ITU) and International Organization for Standardization (ISO) are proposed a series of Video compression standard, including H.261, MPEG-1, H.262/MPEG-2, H.263, MPEG-4, H.264/AVC and H.265/ HEVC.The video encoding standard of main flow is that H.264/AVC ITU and ISO issued in 2003 at present, up-to-date Video coding mark Standard is that H.265/HEVC ITU and ISO issued in 2013.Above-mentioned video encoding standard is mainly for the nature of camera acquisition Video scene is compressed, and is mainly used in the fields such as video monitoring, video conference, DTV and digital camera, and all adopts Use YUV chrominance space.YUV chrominance space include luminance signal Y and two carrier chrominance signals U, V, RGB color degree can be passed through Space is converted to (see video field classics English books " Video Demystified:A Handbook for the Digital Engineer, FifthEdition ", Keith Jack, 2007).In the video of YUV444 form, Y, U and V tri- The sampling rate of individual component is identical, and each pixel comprises three component datas, after 8 bit quantizations, and uncompressed every Individual pixel takies 3 bytes.In the video of YUV420 form, each pixel has Y-component data, every 2 × 2 pixel sides Battle array has a U component data and V component data, i.e. U, V component in the horizontal direction with all carry out two on vertical direction/ One extraction.In order to improve video compression efficiency, and consider the feature that human eye is low to the resolution of U, V component, these video pressures YUV420 form is mainly compressed by contracting standard.Screen video, after the color space convert of RGB to YUV, can be adopted Carry out compression coding with these compression standards, but add the mixing volume of entropy code owing to these compression standards use prediction to add conversion Code framework, overall calculation complexity is very big, and can dramatically increase numeral KVM switcher realizes cost and computation delay, reduces aobvious Show the response speed of picture.Additionally, these compression standards do not consider the feature of screen video, directly application will introduce easily quilt The video quality loss that user discovers.

The video compression technology of numeral KVM switcher does not require nothing more than and reduces the data volume of video code flow, holding output video Code stream steady, to improve the response speed of main control platform display picture, also requires the computation complexity of compression algorithm itself not Can be too high, realize cost reducing algorithm.Chinese patent (proprietary term: the video compression system) profit of Patent No. 03816346.2 Video compress is carried out with the loss of the redundancy on computer screen and user acceptable video.Though the compression method of this patent So computation complexity is relatively low, but it carries out the data compression of Pixel-level based on RGB color degree space, uses the fixed code of byte-aligned Flow structure, overall compression efficiency is the highest, especially overall to the screen video scene compression efficiency of gradual change texture and complex texture Relatively low.It addition, the compression method of this patent at video scene during simple textures picture is switched to complex texture picture The video code flow transient data amount produced is excessive, network transmission can be caused to block up, have a strong impact on the sound of main control platform display picture Answer speed.Chinese patent (the proprietary term: computor-keyboard, mouse and the transmission side of VGA screen signal of Patent No. 98120137.7 Method) utilize three kinds of video signals of VGA screen and additional transmission signal line, VGA screen signal is transmitted main control computer afield, User is made can normally to operate object computer.This patent uses specific transmission line and host-host protocol to transmit screen video letter Number, it is impossible to being transmitted on general digital network, it uses distance to be restricted.Patent No. 200610080828.8 Chinese patent (proprietary term: a kind of video-frequency compression method) realizes the flat of KVM video code flow by controlling the change of quantization parameter Steady output, improves the response speed of KVM display picture.But the enforcement of this patent needs enterprising on existing video standard basis OK, overall calculation complexity is higher, can substantially increase the process time delay of video compress and realize cost.Additionally, this patent Video-frequency compression method, owing to needs carry out picture change detection to every frame and each macro block will be calculated quantization parameter, enters one Step adds its computation complexity.

Summary of the invention

In order to overcome the overall transfer data volume of screen video data in numeral kvm system huge and complicated video scene The problem that lower peak transmission data volume is excessive, the invention provides a kind of screen video compression method towards numeral KVM device, Under limited computation complexity, screen video data are compressed, be effectively reduced screen video code stream overall data amount and Peak-data amount, and keep good reconstruction video quality.

A kind of screen video compression method towards numeral KVM switcher, comprises the following steps:

(1) frame screen video data are inputted；

(2) frame originating point information of current video frame is write code stream；

(3) from current video frame, one uncoded chromatic component subframe of acquisition is as current chroma component sub-frame, to this Subframe carries out data block division, and calculates total number of data block；

(4) from current chroma component sub-frame, a uncoded data block is obtained as current block；

(5) calculate current block coding information under each candidate coding pattern and rebuild data, and choosing final coding Pattern and reconstruction data；

(6) according to the final coding mode of current block, the coding information of current block is write code stream；

(7) repeat step (4) to (6), complete coding and the reconstruction of all data blocks in current chroma component sub-frame；

(8) to current video frame written into code stream carry out bit padding to realize byte-aligned；

(9) repeat step (3) to (8), complete coding and the reconstruction of all chromatic component subframes in current video frame；

(10) code stream producing current video frame carries out frame synchronization head escape process, exports final compressed bit stream.

In step (1), described frame screen video data refer to that the frame that KVM switcher gathers uses YUV colourity The screen video image in space, for the video compress of subsequent step.The pixel resolution of this two field picture is H₀×V₀, wherein H₀ For the pixel number in horizontal resolution, i.e. horizontal direction, V₀For the pixel in vertical resolution, i.e. vertical direction Number.The concrete chrominance space form of the screen video data of support of the present invention is the one in YUV420, YUV422 and YUV444, The each component data of Y, U and V represents with 8 bits, and each screen video frame is divided into three chromatic component subframes: all Y divide Amount data composition H₁×V₁Two-dimensional data array, be designated as Y-component subframe, wherein H₁Represent Y-component subframe in the horizontal direction Data amount check, V₁Represent the data amount check of Y-component subframe in the vertical direction；All U component datas composition H₂×V₂Two-dimemsional number According to array, it is designated as U component sub-frame, wherein H₂Represent U component sub-frame data amount check in the horizontal direction, V₂Represent U component sub-frame The data amount check of in the vertical direction；All V component data composition H₃×V₃Two-dimensional data array, be designated as V component subframe, its Middle H₃Represent V component subframe data amount check in the horizontal direction, V₃Represent the data amount check of V component subframe in the vertical direction. In these three YUV chrominance space form, the horizontal direction data amount check H of Y-component subframe₁Divide equal to the level of current frame image Resolution H₀, the vertical direction data amount check V of Y-component subframe₁Vertical resolution V equal to current frame image₀；The water of U component sub-frame Square to data amount check H₂With vertical direction data amount check V₂, the horizontal direction data amount check H of V component subframe₃With vertical direction number According to number V₃, with H₀、V₀Between numerical relation be shown in Table 1.

Table 1

In step (2), described frame originating point information includes:

1) the frame synchronization leader of 4 byte representations knows SyncF, and first three byte value is 0xFF, and the 4th byte value is 0xFE, for the beginning of mark one frame code stream.SyncF must write code stream at byte-aligned, and must press byte order transmission To decoding end, the higher bit position of each byte is first transmitted, and forms the bit stream of 4 byte representations (32 bits).SyncF writes The value (being 0xFF) of first three byte of code stream is different from the value of last byte (0xFE), and this makes to write code stream prior to SyncF Byte (belonging to former frame code stream) to be any numerical value form SyncF all without first three byte with SyncF, can avoid solving The code end Wrong localization to frame head original position.

2) the resolution mark PicR of the present frame screen video image that 6 bits represent, its span is 1 to 24, Represent 24 kinds of typical resolution in numeral kvm system, screen video image horizontal resolution H that each value is corresponding respectively₀ With vertical resolution V₀It is shown in Table 2, reserved 0,25 to 63 totally 40 numerical value.The PicR occurrence of write code stream is by actually entering screen The resolution synopsis 2 of video image obtains.

Table 2

PicR	Horizontal resolution H<sub>0</sub>	Vertically resolution V<sub>0</sub>
			1	640	350
2	640	400
			3	640	480
4	720	400
			5	768	576
6	800	600
			7	848	480
8	1024	768
			9	1152	864
10	1280	720
			11	1280	768
12	1280	800
			13	1280	960
14	1280	1024
			15	1360	768
16	1366	768
			17	1440	900
18	1400	1050
			19	1600	900
20	1600	1024
			21	1600	1200
22	1680	1050
			23	1920	1080
24	1920	1200

3) the chrominance space format identification (FID) ColorF that 3 bits represent, characterizes the colourity sky that current video frame specifically uses Between form, be worth for 0b000 represent employing YUV420 form, be worth for 0b001 represent employing YUV422 form, be worth and represent for 0b010 Use YUV444 form, reserved 0b011 to 0b111.U and the V component data amount check of present frame employing YUV422 form are The half of YUV444 form；Use the U of YUV420 form and half that V component data amount check is YUV422 form, be only / 4th of YUV444 form.Owing to human eye is relatively low to the resolution of U and V component data, YUV420 form is selected to have non- Very close to the colourity well as subjective video quality of YUV422 and YUV444 form, YUV422 form is selected to have closer to YUV444 lattice The colourity well as subjective video quality of formula.Therefore, the concrete value of ColorF can be according to numeral kvm system to colourity video quality and pressure The demand of contracting ratio is chosen flexibly, the highest to colourity video quality demands, may select YUV444 form, requires compression ratio Height then may select YUV420 form, is desirable that higher to colourity video quality and compression ratio, then may select YUV422 form.

4) the data block partition mode mark BP that 4 bits represent_MODE, characterize and each chromatic component subframe carried out data The ultimate unit h that block divides_p×v_p, i.e. horizontal direction master data number h_pWith vertical direction master data number v_p, BP_MODEValue Represent employing 4 × 4 partition mode for 0b0000, be worth and represent employing 8 × 4 partition mode for 0b0001, be worth and represent for 0b0010 and adopt With 4 × 8 partition modes, it is worth and represents employing 8 × 8 partition mode for 0b0011, reserved 12 numerical value from 0b0100 to 0b1111. The h of 4 × 4 partition modes_pEqual to 4, v_pEqual to 4；The h of 8 × 4 partition modes_pEqual to 8, v_pEqual to 4；The h of 4 × 8 partition modes_pDeng In 4, v_pEqual to 8；The h of 8 × 8 partition modes_pEqual to 8, v_pEqual to 8.Use less block dividing mode can improve compression effect Rate, but owing to block number increases, extra amount of calculation also can be increased.Therefore, numeral kvm system can be according to amount of calculation and pressure The demand of contracting ratio selects BP_MODEOccurrence, if requiring that amount of calculation is the least, then can be by BP_MODEValue be set to 0b0011, If requiring that compression ratio is the biggest, then can be by BP_MODEValue be set to 0b0000, due to BP in the case of other_MODEBe set to 0b0001 or 0b0010 has the amount of calculation of same levels, can select occurrence according to the compression ratio size under typical case's application scenarios.

5) the inter prediction enable mark TP that 1 bit represents_EN, its value is that 0b0 represents that the coding of present frame does not allows to make With inter prediction, the reconstruction data of previous coded frame i.e. can not be used to predict current frame data, its value is that 0b1 represents present frame Coding allow use inter prediction, i.e. allow use previous coded frame reconstruction data predict current frame data.TP_ENValue is 0b1 can be effectively improved the compression efficiency of present frame, but also makes the encoding code stream of present frame have time domain dependency.If present frame Code stream lose or error code occur during transmitting, it will make reconstruction errors diffuse up in time domain side, until TP occurs_ENValue Till the frame of 0b0.TP in the present invention_ENSetting there is following restriction: (a) present frame is the 1st coded frame, then TP_ENCan only It is set to 0b0.B the resolution mark PicR of () current frame video image is different from former frame, then TP_ENIt may be only configured to 0b0. C the chrominance space format identification (FID) ColorF of () present frame is different from former frame, then TP_ENIt may be only configured to 0b0.In other situation Under, TP in present frame_ENValue can according to numeral kvm system application demand and the bit error rate situation of compression ratio are arranged. It addition, regardless of TP_ENValue how to arrange, the present invention allows present frame to carry out spatial prediction, i.e. uses in present frame encoded The reconstruction data of data predict the data to be encoded in present frame.

6) the frame level image quality mode PicQ that 2 bits represent, characterizes the subjective quality of present frame coding and rebuilding image Grade, its value is that 0b00 represents lossless mode, is worth and represents for 0b01 and damage clear pattern, is worth and represents for 0b10 and damage equilibrium model Formula, reserved 0b11；If present frame uses lossless mode, then its frame level quantization step QStep value is 1；If present frame uses and damages Clear pattern, then its frame level quantization step QStep value is 2；If present frame uses and damages balanced mode, then its frame level quantization step It is 4 for QStep value.The value of QStep is the biggest, and quantization error is the biggest, and the QStep damaging balanced mode is damage clear pattern two Times, rebuild image definition just poorer than damaging clear pattern.QStep will be used in subsequent step the prediction residual amount of carrying out Changing and inverse quantization, quantify and the computational efficiency of inverse quantization to promote prediction residual, the QStep value of the present invention is all the power of 2, So quantify all to be converted to shift operation with the division in de-quantization process and multiplying.In the present invention, present frame frame level quantifies Shift amount shift takes the logarithm by 2 the integer obtained equal to QStep.When QStep value is 1, then shift value is 0；When QStep value Be 2, then shift value is 1；When QStep value is 4, then shift value is 2；By the present invention in that and carry out shifting realizing with shift Prediction residual is quantified and inverse quantization.In order to ensure the gross of video image, in the present invention, the maximum of QStep is only To 4.

7) the FrameN value of FrameN: the first coded frame of frame number that 16 bits represent is set to 0, follow-up every frame FrameN adds 1 equal to the FrameN of its former frame, when FrameN value is more than 65535, then it is set to 0 again.

For the ease of number of bits and the description of numerical value, in the present invention, 0b is the prefix of binary mode numeric representation, its After numeral be binary numeral, write code stream coding information value can use other system mode to represent equally, such as ten enter System and hexadecimal, it is impossible to limit protection scope of the present invention to represent only with binary mode.

In step (2), frame originating point information writes code stream in the following order:

(2-1) at byte-aligned, write frame sync identifications SyncF of 4 bytes；

(2-2) the resolution mark PicR of write present frame screen video image；

(2-3) write chrominance space format identification (FID) ColorF；

(2-4) writing data blocks partition mode mark BP_MODE；

(2-5) write inter prediction enables mark TP_EN；

(2-6) write frame level image quality mode PicQ；

(2-7) the frame number FrameN of present frame is write.

Further, in step (2), each numerical value be its higher bit position first write code stream (i.e. first pass through network pass Deliver to decoding end), write code stream behind low bit position；All reserved numerical value, in an encoding process all without use, both can improve The decoding end error detecing capability to preamble bitstream, the most also the follow-up semantic extension for the present invention provides space.

In step (3), specifically comprise the following steps that

(3-1) first obtain a uncoded colourity by the order of Y-component subframe, U component sub-frame, V component subframe to divide Quantum frame is as current chroma component sub-frame, H_kAnd V_kBe respectively current chroma component sub-frame in the horizontal direction with on vertical direction Data amount check, k is the index of current chroma component sub-frame, and k value is 1 expression Y-component subframe, and k value is 2 expression U component sub-frame, K value is 3 expression V component subframes；

(3-2) then according to the BP in step (2)_MODEObtain data block and divide ultimate unit h_P×v_P, h_PFor horizontal direction The data amount check divided, v_PThe data amount check divided for vertical direction；

(3-3) then ultimate unit h is divided according to data block_P×v_PBy the order of raster scanning by current chroma component Frame is divided into the two-dimensional rectangle data block to be encoded of multiple h × v size, and h is data block data amount check in the horizontal direction, V is the data amount check of data block in the vertical direction；For not comprising the data block of right margin, h value is BP in step (2)_MODE Corresponding h_p；For not comprising the data block of lower boundary, v is BP in step (2)_MODECorresponding v_p；For comprising the number of right margin According to block, if the horizontal direction data amount check H of current chroma component sub-frame_kCan be by h_pDivide exactly, then h value is h_p, otherwise h value is H_kExcept h_p The remainder obtained；For comprising the data block of lower boundary, if the vertical direction data amount check V of current chroma component sub-frame_kCan be by v_p Divide exactly, then v value is v_p, otherwise v value is V_kExcept v_pThe remainder obtained；

(3-4) data block number H of current chroma component sub-frame horizontal direction finally it is calculated by formula (1)_blk, press Formula (2) is calculated data block number V of current chroma component sub-frame vertical direction_blk, it is calculated currently by formula (3) Total number N of data block of chromatic component subframe_blk。

N_blk=H_blk×V_blk (3)

In step (3), the order of described raster scanning is conventional the starting from a left side from the upper left corner of field of video compression The order traveled through is carried out from top to bottom to the right side.

In step (4), from current chroma component sub-frame, obtain h × v size not by the order of raster scanning Coding two-dimensional rectangle data block is as current block.

In step (5), described candidate coding pattern includes:

1) interframe associative mode (IC_MODE):

In the present invention, current block selects IC_MODE to have two conditions as its effective candidate coding pattern, wherein first Condition is: present frame enables mark TP written into the inter prediction of code stream_ENValue is 0b1, i.e. allows to use the weight of previous coded frame Build data prediction current frame data.

Using this pattern to encode, the coding information of current block and reconstruction data are calculated as follows obtaining:

For each initial data P in current block, its predictive value Pred^ICFor identical chromatic component in previous coded frame The reconstruction data of frame and same spatial location, its prediction residual D^ICBe calculated by formula (4), prediction residual symbol Sign^ICPress Formula (5) is calculated, quantifies residual error QD^ICIt is calculated by formula (6), formula (7) and formula (8), is rebuild data R^ICBy public affairs Formula (9) is calculated.

D^IC=P-Pred^IC (4)

${\mathrm{Sign}}^{IC}=\left\{\begin{array}{ccc}0,& if& D^{IC}\&GreaterEqual;0\\ 1,& if& D^{IC}<0\end{array}\right.---\left(5\right)$

${\mathrm{QD}}_{Tmp}^{IC}=\left(\right|D^{IC}|+(QStep2>>1\left)\right)>>shift2---\left(6\right)$

$QStep2=\left\{\begin{array}{cc}QStep>>1,& \begin{array}{cc}if& QStep>1\end{array}\\ 1,& others\end{array}\right.---\left(8\right)$

$R^{IC}=\left\{\begin{array}{ccc}\min ({\mathrm{Pred}}^{IC}+({\mathrm{QD}}^{IC}<<shift2),255),& if& {\mathrm{Sign}}^{IC}=0\\ \max ({\mathrm{Pred}}^{IC}-({\mathrm{QD}}^{IC}<<shift2),0),& if& {\mathrm{Sign}}^{IC}=1\end{array}\right.---\left(9\right)$

In formula (5), Sign^ICValue be the symbol of 0 expression prediction residual for just, value is the symbol of 1 expression prediction residual It is negative.In formula (6), QD^IC _TmpQuantify residual error for IC_MODE temporarily, > > symbol represents shift right operation, | D^IC| represent D^IC Take absolute value, | D^IC| the half (i.e. QStep2 > > 1) plus QStep2 is to round up final quantization result；For Improving the quantified precision of IC_MODE prediction residual amplitude, what the present invention used in formula (6) halves quantization step QStep2 Being calculated by formula (8), if QStep is more than 1, then QStep2 value is the half of frame level quantization step QStep, if QStep etc. In 1, then QStep2 value is 1；Halve shift amount shift2 to be taken the logarithm by 2 by QStep2 and be calculated, be i.e. 1 when QStep2 value Time, the value of shift2 is 0, and when QStep2 value is 2, the value of shift2 is 1.In formula (7), in order to improve frame level figure picture element Amount, for damaging the compression efficiency of static scene in the case of balanced mode, works as QD^ICValue is 1 and QStep2 value when being 2, by QD^ICBy force System is set to 0, is the number of zero to increase quantization residual error in current block, improves subsequent compression efficiency, QD in the case of other^ICKeep not Become.In formula (9), < < symbol represents that shift left operation, min () are to take the smaller value function of two input data, and max () is for taking Two input data higher value functions, with guarantee rebuild data between 0 to 255, i.e. in the range of 8 bits represent.For Avoid quantifying and the division in de-quantization process and multiplying, the present invention in the quantization operations of formula (6) with moving right Position replaces division, replaces multiplication by shifted left in the inverse quantization computing of formula (9).

In order to enable decoding end to rebuild each data of current block by formula (9), first the present invention would indicate that IC_MODE Coding mode mark ModeID^ICEnrolling code stream, represent with 2 bits, its value is 0b00, enables decoding end according to coding mode Mark obtains the coding mode of current block, and then obtains Pred^ICTo realize rebuilding.

Then according to all QD of current block^ICIn maximum QD^IC _maxEach QD is calculated by formula (10)^ICEnroll code stream Number of bits QDBits^IC.In formula (10), work as QD^IC _maxValue is 0, shows all QD of current block^ICValue is all 0, then without disappearing The each QD of loss-rate spy's actual coding^IC, the present invention is by QDBits^ICValue be set to 0；Work as QD^IC _maxMore than 0, then all QD of current block^IC Value is in the range of [0, QD^IC _max], each QD^ICAt least useIndividual bit represents, in order to reduce QD as far as possible^IC's Number of coded bits, the present invention is by QDBits^ICValue be set to minimum

Then according to calculated QDBits^ICThe stand growth model mark AZFlag that 1 bit is represented^ICEnroll code stream: when QDBits^ICValue is equal to 0, then by AZFlag^ICValue is set to 0b1, represents the QD of current block^ICIt is all zero, need not be by QDBits^ICEnroll Code stream；Work as QDBits^ICValue is more than 0, then by AZFlag^ICValue is set to 0b0, represents that current block exists non-zero QD^IC, must be by QDBits^IC Enroll code stream.In order to reduce number of coded bits and in view of QDBits^ICTypical ranges, the unified restriction of the present invention only uses 3 bits By QDBits^ICEnroll code stream, QDBits^ICAllow in the range of [0,7].

Therefore, in the present invention, current block selects the IC_MODE as second condition of its effective candidate coding pattern to be QDBits^ICIt is not more than 7.Work as QDBits^ICMore than 7, then cannot be enrolled code stream with 3 bits, IC_MODE in this case The final coding mode of current block cannot be become, be not the most effective candidate coding pattern of current block, after this pattern must being terminated Continuous calculating.It is in the case of 1 (shift2 value is 0, does not shifts) that this situation only appears in QStep2 value, and owing to regarding Frequency evidence has the strongest dependency, major part QD in time domain^ICValue be both less than 128, can be in the range of the expression of 7 bits.

Finally according to QDBits^ICSign to each data in two kinds of situation^ICAnd QD^ICEncode:

A () works as QDBits^ICValue is more than 0, and current block exists non-zero QD^IC, then by all of for current block QD^ICAnd Sign^ICAll compile Enter code stream, the most each Sign^ICRepresent with 1 bit, each QD^ICUse QDBits^ICIndividual bit represents.

B () works as QDBits^ICValue is equal to 0, the QD of current block^ICBe all zero, i.e. current block is that IC_MODE quantifies residual error complete zero Block, then Sign^ICDo not affect the reconstructed results of formula (9), all Sign in current block^ICAnd QD^ICAll need not enroll code stream.For Improving the code efficiency of still frame scene, support of the present invention is to multiple continuous print QD^ICStand growth model carries out Unified coding.Therefore The present invention is then written to the consecutive identical monodrome block identification ContiFlag that 1 bit represents^IC, its value is 0b0, represents only complete to 1 Zero piece encodes, and terminates the coding of current block；Its value is that 0b1 represents the continuous QD started from current block^ICStand growth model (its Number is designated as ContiCnt^IC, its value is more than 1) and carry out Unified coding.The present invention is by ContiCnt^ICValue after subtracting 1 is used ContiCntBits^ICIndividual bit represents and enrolls code stream.In order to reduce ContiCnt^ICNumber of coded bits, the present invention presses formula (11) four kinds of situations are divided to be calculated ContiCntBits^IC, ContiCntBits in the case of first three^ICIt is all ContiCnt^IC Corresponding higher limit is taken the logarithm by 2 and is obtained, and last a kind of situation is N_blkRound up after taking the logarithm by 2 and obtain.In formula (11) In, N_blkFor the data block number of current chroma component sub-frame, it is calculated by step (3).In order to enable decoding end correct Resolve ContiCnt^IC, enrolling ContiCnt^ICBefore must be first by ContiCntBits^ICIdentification information enroll code stream.In order to Reduce ContiCntBits^ICNumber of coded bits, and in view of ContiCntBits^ICValue only have four kinds of situations, the present invention is only With 2 bits by ContiCntBits^ICCode identification (be designated as ContiCntBitsIdx^IC) enroll code stream, ContiCntBitsIdx^ICWith ContiCntBits^ICCorresponding relation such as formula (12) shown in.

According to encoding information above, the continuous blocks using IC_MODE to start current block or current block carry out coding and consume Number of coded bits CBits^ICIt is calculated by formula (13).

2) monodrome raw mode (SO_MODE):

In the present invention, current block selects SO_MODE as its effective candidate coding pattern only one of which condition: current block is The all data of monodrome block, i.e. current block are the most equal, are all monodrome P of current block_S。

Using this pattern to encode, coding side must be by the pattern information of SO_MODE and P_SInformation enrolls code stream.In order to carry High this pattern of employing carries out the picture quality encoded, and this pattern is not to P_SQuantifying, coding mode is the data block of SO_MODE Reconstruction data be all P_S.Using this pattern to carry out the compression efficiency encoded to improve, this pattern is by P_SEnroll the mode of code stream Have two kinds: (a) directly with 8 bits by P_SEnroll code stream；B () is also SO_MODE when the coding mode of the adjacent upper block in space And its P_SP with current block_SEqual, then need not P_SEnrolling code stream, decoding end can obtain P from decoded upper block_S。 In order to improve the compression efficiency using this pattern, support of the present invention consecutive identical monodrome block (its number to starting from current block It is designated as ContiCnt^SO, its value is more than 1) and carry out Unified coding.

In order to make decoding end be obtained in that the reconstruction data of the continuous blocks headed by the reconstruction data of current block or current block, this It is as follows that the code stream that invention uses SO_MODE to carry out encoding enrolls mode: first the coding mode of SO_MODE is identified by (a) ModeID^SOEnrolling code stream, 2 bits represent, are worth for 0b01.B monodrome coded system that then 1 bit is represented by () CodPsFlag^SOEnrolling code stream, its value is monodrome P that coding mode is SO_MODE and top that 0b0 represents upper block_SWith currently Monodrome P of block_SEqual, monodrome P of current block_SNot enrolling code stream, decoding end is by obtaining P from upper block_SRealize current block Data reconstruction, its value is that 0b1 represents monodrome P represented by 8 bits_SEnrolling code stream, decoding end obtains P by resolving code stream_SCome real The data reconstruction of existing current block.C consecutive identical monodrome block identification ContiFlag that 1 bit is represented by () again^SOEnroll code stream, when ContiFlag^SOValue be 0b0, represent that only current block enrolls code stream, terminates the coding of current block；Work as ContiFlag^SOValue For 0b1, represent the continuous ContiCnt headed by current block^SOIndividual block uses SO_MODE to carry out encoding and P between each block_S Equal, then by ContiCnt^SOValue ContiCntBits after subtracting 1^SOIndividual bit represents and enrolls code stream.In order to reduce ContiCnt^SOThe number of coded bits subtracting 1, the present invention is according to ContiCnt^SOCalculate by four kinds of situations of formula (14) point ContiCntBits^SO, ContiCntBits in the case of first three^SOIt is all ContiCnt^SOCorresponding higher limit is taken the logarithm by 2 Obtaining, last a kind of situation is N_blkRound up after taking the logarithm by 2 and obtain.In order to enable decoding end correctly to resolve ContiCnt^SO, enrolling ContiCnt^SOMust be first by ContiCntBits before subtracting 1^SOCoding information enroll code stream.In order to subtract Little ContiCntBits^SONumber of coded bits, and in view of ContiCntBits^SOValue only have four kinds of situations, the present invention only uses 2 bits are by ContiCntBits^SOCode identification (be designated as ContiCntBitsIdx^SO) enroll code stream, ContiCntBitsIdx^SOWith ContiCntBits^SOCorresponding relation such as formula (15) shown in.

According to encoding information above, the continuous blocks using SO_MODE to start current block or current block carry out coding and consume Number of coded bits CBits^SOIt is calculated by formula (16).

CBits^SO=2+1+8 × CodPsFlag^SO+1+ContiFlag^SO×(2+ContiCntBits^SO) (16)

3) horizontal pointwise pattern (HP_MODE):

HP_MODE uses the reconstruction data of adjacent position on the left of horizontal direction to carry out prediction point-by point, and enters prediction residual Row shift quantization, displacement inverse quantization and reconstruction: to each initial data P in current block, when P is in current chroma component sub-frame Left margin, then the predictive value Pred of P^HPIt is set to 128, otherwise Pred^HPIt is all reconstruction data R of adjacent left-hand position, P space_L；P Prediction residual D^HPBe calculated by formula (17), prediction residual symbol Sign^HPIt is calculated by formula (18), is quantified residual error QD^HPIt is calculated by formula (19), is rebuild data R^HPIt is calculated by formula (20).

D^HP=P-Pred^HP (17)

${\mathrm{Sign}}^{HP}=\left\{\begin{array}{ccc}0,& if& D^{HP}\&GreaterEqual;0\\ 1,& if& D^{HP}<0\end{array}\right.---\left(18\right)$

QD^HP=(| D^HP|+(QStep ＞ ＞ 1)) ＞ ＞ shift (19)

$R^{HP}=\left\{\begin{array}{ccc}\min ({\mathrm{Pred}}^{HP}+({\mathrm{QD}}^{HP}<<shift),255),& if& {\mathrm{Sign}}^{HP}=0\\ \max ({\mathrm{Pred}}^{HP}-({\mathrm{QD}}^{HP}<<shift),0),& if& {\mathrm{Sign}}^{HP}=1\end{array}\right.---\left(20\right)$

In order to allow decoding end can rebuild each data of current block by formula (20), coding side first must be by HP_MODE Coding mode mark ModeID^HPEnroll code stream, ModeID in the present invention^HPRepresent with 3 bits, be worth for 0b100.Decoding end exists After resolving the coding mode mark ModeID that code stream obtains current block, when ModeID value is ModeID^HP, then explanation current block uses HP_MODE encodes, and then obtains each Pred of current block^HP。

Maximum quantization residual error QD then according to current block^HP _maxEach QD is calculated by formula (21)^HPEnroll the bit of code stream Number QDBits^HP.In formula (21), work as QD^HP _maxEqual to 0, show all QD of current block^HPBe all 0, i.e. current block is HP_MODE Quantify residual error stand growth model, then without consuming each QD of bits of encoded^HP, the present invention is by QDBits^HPIt is set to 0；Work as QD^HP _maxMore than 0, The then all QD of current block^HPIn the range of [0, QD^HP _max], each QD^HPAt least useIndividual bit represents, this Bright by QDBits^HPIt is set toIn order to reduce code stream bit number and in view of QDBits^HPTypical ranges, The QDBits that the present invention will only represent with 3 bits^HPEnroll code stream, QDBits^HPAllow in the range of [0,7].

Therefore, in the present invention, current block selects the HP_MODE as the unique conditional of its effective candidate coding pattern to be: QDBits^HPIt is not more than 7.Work as QDBits^HPMore than 7, then cannot be enrolled code stream with 3 bits, HP_MODE in this case The final coding mode of current block cannot be become, be not the most effective candidate coding pattern of current block, after this pattern must being terminated Continuous calculating.

Finally according to QDBits^HPSign by each data^HPAnd QD^HPEnroll code stream: work as QDBits^HPEqual to 0, show to work as The QD of front piece^HPIt is all 0, Sign^HPDo not affect the reconstructed results of formula (20), therefore all Sign in current block^HPAnd QD^HPThe most not Need to enroll code stream；Work as QDBits^HPMore than 0, show that current block exists certain QD^HPMore than 0, the present invention is all of by current block QD^HPAnd Sign^HPAll enroll code stream, the most each Sign^HPAll with 1 bit represent, each QD^HPAll use QDBits^HPIndividual bit table Show.

According to encoding information above, use HP_MODE that current block carries out number of coded bits CBits that coding consumes^HPPress Formula (22) is calculated.

4) vertical pointwise pattern (VP_MODE):

VP_MODE uses the reconstruction data of adjacent position above vertical direction to carry out prediction point-by point, and enters prediction residual Row shift quantization, displacement inverse quantization and reconstruction: to each initial data P in current block, when P is in current chroma component sub-frame Coboundary, then the predictive value Pred of P^VPIt is set to 128, otherwise Pred^VPIt is all reconstruction data R of position adjacent and above, P space_U；P Prediction residual D^VPBe calculated by formula (23), prediction residual symbol Sign^VPIt is calculated by formula (24), is quantified residual error QD^VPIt is calculated by formula (25), is rebuild data R^VPIt is calculated by formula (26).

D^VP=P-Pred^VP (23)

${\mathrm{Sign}}^{VP}=\left\{\begin{array}{ccc}0,& if& D^{VP}\&GreaterEqual;0\\ 1,& if& D^{VP}<0\end{array}\right.---\left(24\right)$

QD^VP=(| D^VP|+(QStep ＞ ＞ 1)) ＞ ＞ shift (25)

$R^{VP}=\left\{\begin{array}{ccc}\min ({\mathrm{Pred}}^{VP}+({\mathrm{QD}}^{VP}<<shift),255),& if& {\mathrm{Sign}}^{VP}=0\\ \max ({\mathrm{Pred}}^{VP}-({\mathrm{QD}}^{VP}<<shift),0),& if& {\mathrm{Sign}}^{VP}=1\end{array}\right.---\left(26\right)$

In order to allow decoding end can rebuild each data of current block by formula (26), coding side first must be by VP_MODE Coding mode mark ModeID^VPEnroll code stream, ModeID in the present invention^VPRepresent with 3 bits, be worth for 0b101.Decoding end exists After resolving the coding mode mark ModeID that code stream obtains current block, when ModeID value is ModeID^VP, then explanation current block uses VP_MODE encodes, and then obtains each Pred of current block^VP。

Maximum quantization residual error QD then according to current block^VP _maxEach QD is calculated by formula (27)^VPEnroll the bit of code stream Number QDBits^VP.In formula (27), work as QD^VP _maxEqual to 0, show all QD of current block^VPValue is all 0, i.e. current block is VP_ MODE quantifies residual error stand growth model, then without consuming each QD of bits of encoded^VP, the present invention is by QDBits^VPIt is set to 0；Work as QD^VP _maxGreatly In 0, then all QD of current block^VPIn the range of [0, QD^VP _max], each QD^VPAt least useIndividual bit represents, The present invention is by QDBits^VPIt is set toIn order to reduce code stream bit number and in view of QDBits^VPCommon model Enclose, the QDBits that the present invention will only represent with 3 bits^VPEnroll code stream, QDBits^VPAllow in the range of [0,7].

Therefore, in the present invention, current block selects the VP_MODE as the unique conditional of its effective candidate coding pattern to be: QDBits^VPIt is not more than 7.Work as QDBits^VPMore than 7, then cannot be enrolled code stream with 3 bits, VP_MODE in this case The final coding mode of current block cannot be become, be not the most effective candidate coding pattern of current block, after this pattern must being terminated Continuous calculating.

Finally according to QDBits^VPSign by each data^VPAnd QD^VPEnroll code stream: work as QDBits^VPEqual to 0, show to work as The QD of front piece^VPIt is all 0, Sign^VPDo not affect the reconstructed results of formula (26), now all Sign in current block^VPAnd QD^VPThe most not Need to enroll code stream；Work as QDBits^VPMore than 0, show that current block exists certain QD^VPMore than 0, therefore the present invention is by current block institute Some QD^VPAnd Sign^VPAll enroll code stream, the most each Sign^VPAll with 1 bit represent, each QD^VPAll use QDBits^VPIndividual ratio Special expression.

According to encoding information above, use VP_MODE that current block carries out number of coded bits CBits that coding consumes^VPPress Formula (28) is calculated.

5) level of complexity pattern (CH_MODE):

Using this pattern to encode, each row of data of current block has two kinds of optional coded systems: horizontal forecast quantization side Formula and direct quantification manner.

In all data row using horizontal forecast quantification manner, use the reconstruction number of adjacent position on the left of horizontal direction According to carrying out prediction point-by point, and prediction residual is carried out shift quantization, displacement inverse quantization and reconstruction: each original in current line Data P, when P is in the left margin of current chroma component sub-frame, then the predictive value Pred of P^CHIt is set to 128, otherwise Pred^CHIt is all P Reconstruction data R of adjacent left-hand position, space_L；Prediction residual D of P^CHBe calculated by formula (29), prediction residual symbol Sign^CHIt is calculated by formula (30), is quantified residual error QD^CHIt is calculated by formula (31), is rebuild data R^CHBased on formula (32) Obtain.

D^CH=P-Pred^CH (29)

${\mathrm{Sign}}^{CH}=\left\{\begin{array}{ccc}0,& if& D^{CH}\&GreaterEqual;0\\ 1,& if& D^{CH}<0\end{array}\right.---\left(30\right)$

QD^CH=(| D^CH|+(QStep ＞ ＞ 1)) ＞ ＞ shift (31)

$R^{CH}=\left\{\begin{array}{ccc}\min ({\mathrm{Pred}}^{CH}+({\mathrm{QD}}^{CH}<<shift),255),& if& {\mathrm{Sign}}^{CH}=0\\ \max ({\mathrm{Pred}}^{CH}-({\mathrm{QD}}^{CH}<<shift),0),& if& {\mathrm{Sign}}^{CH}=1\end{array}\right.---\left(32\right)$

In all data row using direct quantification manner, do not carry out any prediction, each original number to current line According to P, directly press formula (33) and calculate quantized data QP^CH, and press reconstruction data R of formula (34) calculating P^CH。

QP^CH=(P+ (QStep ＞ ＞ 1)) ＞ ＞ shift (33)

R^CH=QP^CH＜ ＜ shift (34)

In order to enable decoding end to rebuild all data row of current block by formula (32) or (34), first the present invention will The coding mode mark ModeID of CH_MODE^CHEnroll code stream, represent with 4 bits, be worth for 0b1100.Then press from top to bottom Coded system RowMode that order will often be gone^CHEnroll code stream, each RowMode^CHRepresenting with 1 bit, (v is for working as v bit altogether The data amount check of front piece of in the vertical direction, is the number of data lines of current block).The RowMode of current line^CHValue represents for 0b0 Current line uses the coded system that horizontal forecast quantifies, and its value is that 0b1 represents that current line uses the coded system directly quantified.

Then the data row of the data row and direct quantification manner that use horizontal forecast quantification manner is encoded respectively:

In all data row using horizontal forecast quantification manner, in order to enable decoding end to rebuild number by formula (32) According to, coding side must be by QD all in current block^CHAnd Sign^CHInformation enroll code stream: the present invention is first from all QD of current block^CHIn Select maximum QD^CH _max, then calculate each QD by formula (35)^CHEnroll the bit number QDBits of code stream^CH.In formula (35), Work as QD^CH _maxEqual to 0, show all of QD of current block^CHBe all 0, i.e. current block be CH_MODE quantify residual error stand growth model, then without Consume bit and encode QD^CH, the present invention is by QDBits^CHIt is set to 0；Work as QD^CH _maxMore than 0, then all QD of current block^CHScope district Between be [0, QD^CH _max], each QD^CHAt least useIndividual bit represents, the present invention is by QDBits^CHIt is set toIn order to reduce QDBits^CHEncoding code stream bit number, the present invention will only represent with 3 bits QDBits^CHEnroll code stream, QDBits^CHAllowed band be [0,7], corresponding QD^CHAllowed band be [0,127].

Therefore, in the present invention, current block selects the CH_MODE as the unique conditional of its effective candidate coding pattern to be: QDBits^CHIt is not more than 7.Work as QDBits^CH(QD is i.e. there is more than 7^CHMore than 127), then cannot be enrolled code stream with 3 bits, In this case CH_MODE cannot become the final coding mode of current block, is not the most effective candidate coding pattern of current block, The subsequent calculations of this pattern must be terminated.To often going, when it exists QD of employing horizontal forecast quantification manner^CHMore than 127, then this row Using horizontal forecast quantification manner is not effective candidate coding pattern of current block by causing CH_MODE.In this case, when The coded system of current line can be changed into another kind of directly quantification manner by front piece, it is to avoid calculated by formula (35) QDBits^CHScope beyond [0,7].

In all data row using direct quantification manner, in order to enable decoding end to rebuild data by formula (34), Coding side must be by all for current block QP^CHEnrolling code stream, the present invention is by each QP^CHAll use QPBits^CHIndividual bit represents and enrolls code Stream.Owing to P is to represent with 8 bits, the QP that P obtains after formula (33) shift quantization^CHOnly need to subtract shift bit table with 8 Show and get final product (shift is that frame level quantifies shift amount), therefore QPBits in the present invention^CHIt is calculated by formula (36).At formula (36) in, QPBits^CHCalculating only the most relevant with shift, all of QPBits of present frame^CHThe most equal.Decoding end can first pass through Frame level image quality mode PicQ in frame originating point information obtains shift, then is calculated QPBits by formula (36)^CH.Therefore, for Minimizing number of coded bits, the present invention is by the QPBits of current block^CHEnroll code stream.

QPBits^CH=8-shift (36)

The present invention is with specific reference to RowMode in current block^CHValue is line number n and the QDBits of 0b1^CHThree kinds of situations are divided to incite somebody to action Coding information (the QP of each data^CH、QD^CHAnd Sign^CH) enroll code stream:

I. when n value is equal to line number v of current block, then all data of current block all use direct quantification manner, only need by Each QP^CHAll use QPBits^CHIndividual bit enrolls code stream, it is not necessary to by QDBits^CH、QD^CHAnd Sign^CHEnroll code stream.

Ii. it is less than line number v and the QDBits of current block when n value^CHDuring equal to 0, all of QD of current block^CHIt is all 0, Sign^CH Do not affect R in formula (32)^CHCalculating, therefore without by Sign^CHAnd QD^CHEnroll code stream.In this case, the present invention is first The QDBits that 3 bits are represented^CHEnroll code stream, then by each QP^CHAll use QPBits^CHIndividual bit enrolls code stream.

Iii., in the case of other, n value is less than line number v of current block, QDBits^CHMore than 0 and less than or equal to 7, need institute Some Sign^CHAnd QD^CHEnroll code stream.In this case, the QDBits that 3 bits are first represented by the present invention^CHEnroll code stream, then will Each Sign^CHAll enroll code stream, by each QD with 1 bit^CHAll use QDBits^CHIndividual bit enrolls code stream, finally by each QP^CHAll use QPBits^CHIndividual bit enrolls code stream.

According to encoding information above, use CH_MODE that current block carries out number of coded bits CBits that coding consumes^CHPress Formula (37) is calculated:

6) complicated vertically pattern (CV_MODE):

Using this pattern to encode, every column data of current block has two kinds of optional coded systems: vertically predict quantization side Formula and direct quantification manner.

In all data row using vertically prediction quantification manner, which uses adjacent position above vertical direction Rebuild data and carry out prediction point-by point, and prediction residual is carried out shift quantization, displacement inverse quantization and reconstruction: every to when in prostatitis Individual initial data P, when P is in the coboundary of current chroma component sub-frame, then the predictive value Pred of P^CVIt is 128, otherwise Pred^CV It is all reconstruction data R of position adjacent and above, P space_U；Prediction residual D of P^CVBe calculated by formula (38), prediction residual accords with Number Sign^CVIt is calculated by formula (39), is quantified residual error QD^CVIt is calculated by formula (40), is rebuild data R^CVBy formula (41) It is calculated.

D^CV=P-Pred^CV (38)

${\mathrm{Sign}}^{CV}=\left\{\begin{array}{ccc}0,& if& D^{CV}\&GreaterEqual;0\\ 1,& if& D^{CV}<0\end{array}\right.---\left(39\right)$

QD^CV=(| D^CV|+(QStep ＞ ＞ 1)) ＞ ＞ shift (40)

$R^{CV}=\left\{\begin{array}{ccc}\min ({\mathrm{Pred}}^{CV}+({\mathrm{QD}}^{CV}<<shift),255),& if& {\mathrm{Sign}}^{CV}=0\\ \max ({\mathrm{Pred}}^{CV}-({\mathrm{QD}}^{CV}<<shift),0),& if& {\mathrm{Sign}}^{CV}=1\end{array}\right.---\left(41\right)$

In all data row using direct quantification manner, do not carry out any prediction, to when each original number in prostatitis According to P, directly press formula (42) and calculate quantized data QP^CV, and press reconstruction data R of formula (43) calculating P^CV。

QP^CV=(P+ (QStep ＞ ＞ 1)) ＞ ＞ shift (42)

R^CV=QP^CV＜ ＜ shift (43)

In order to enable decoding end to rebuild all data row of current block by formula (41) or (43), the present invention is first by table Show the coding mode mark ModeID of CV_MODE^CVEnroll code stream, represent with 4 bits, be worth for 0b1101.Press again from left to right Order is by coded system ColMode of each column^CVEnroll code stream, each ColMode^CVRepresenting with 1 bit, (h is for working as h bit altogether Front piece of data amount check in the horizontal direction, is the data columns of current block).ColMode^CVValue represents when prostatitis is adopted for 0b0 By the coded system that vertically prediction quantifies, its value is that 0b1 represents when prostatitis uses the coded system directly quantified.

Then the data row of the data row and direct quantification manner that use vertical prediction quantification manner are encoded respectively:

In all data row using vertically prediction quantification manner, in order to enable decoding end to rebuild number by formula (41) According to, coding side must be by all for current block QD^CVAnd Sign^CVInformation enroll code stream: the present invention is first from all QD of current block^CVMiddle choosing Go out maximum QD^CV _max, then calculate each QD by formula (44)^CVEnroll the bit number QDBits of code stream^CV.In formula (44), when QD^CV _maxEqual to 0, show all of QD of current block^CVBe all 0, i.e. current block is that CV_MODE quantifies residual error stand growth model, then without disappearing Loss-rate spy encodes QD^CV, the present invention is by QDBits^CVIt is set to 0；Work as QD^CV _maxMore than 0, then all QD of current block^CVRange intervals For [0, QD^CV _max], each QD^CVAt least useIndividual bit represents, the present invention is by QDBits^CVIt is set toIn order to reduce QDBits^CVEncoding code stream bit number, the present invention will only represent with 3 bits QDBits^CVEnroll code stream, QDBits^CVAllowed band be [0,7], corresponding QD^CVAllowed band be [0,127].

Therefore, in the present invention, current block selects the CV_MODE as the unique conditional of its effective candidate coding pattern to be: QDBits^CVIt is not more than 7.Work as QDBits^CV(QD is i.e. there is more than 7^CVMore than 127), then cannot be enrolled code stream with 3 bits, In this case CV_MODE cannot become the final coding mode of current block, is not the most effective candidate coding pattern of current block, The subsequent calculations of this pattern must be terminated.Each column to the vertical prediction quantification manner of employing, when it exists QD^CVMore than 127, then these row Using vertical prediction quantification manner is not effective candidate coding pattern of current block by causing CV_MODE.In this case, when Front piece can will change another kind of directly quantification manner into when the coded system in prostatitis, it is to avoid calculated by formula (44) QDBits^CVScope beyond [0,7].

In all data row using direct quantification manner, in order to enable decoding end to rebuild data by formula (43), Coding side must be by all for current block QP^CVEnrolling code stream, the present invention is by each QP^CVAll use QPBits^CVIndividual bit represents.Owing to P is Represent with 8 bits, the QP that P obtains after formula (42) shift quantization^CVOnly need to subtract shift bit with 8 to represent (shift is that frame level quantifies shift amount), therefore QPBits in the present invention^CVIt is calculated by formula (45).In formula (45), QPBits^CVCalculating only the most relevant with shift, all of QPBits of present frame^CVThe most equal.Decoding end can first pass through frame head letter Frame level image quality mode PicQ in breath obtains shift, then is calculated QPBits by formula (45)^CV.Therefore, in order to reduce Number of coded bits, the present invention is not by the QPBits of current block^CVEnroll code stream.

QPBits^CV=8-shift (45)

Then according to ColMode in current block^CVValue is columns m and QDBits of 0b1^CVDivide three kinds of situations by every number According to coding information (QP^CV、QD^CVAnd Sign^CV) enroll code stream, specific as follows:

I., when m value is equal to the columns h of current block, all data of current block all use direct quantification manner, do not have QDBits^CV、QD^CVAnd Sign^CV, only need to be by each QP^CVAll use QPBits^CVIndividual bit enrolls code stream.

Ii. when m value is less than columns h and QDBits of current block^CVDuring equal to 0, due to all of QD of current block^CVIt is all 0, Sign^CVDo not affect R in formula (41)^CVCalculating, therefore without by Sign^CVAnd QD^CVEnroll code stream.In this case, this The bright QDBits first 3 bits represented^CVEnroll code stream, then by each QP^CVAll use QPBits^CVIndividual bit enrolls code stream.

Iii., in the case of other, m value is less than columns h, QDBits of current block^CVMore than 0 and less than or equal to 7, need by Sign^CVAnd QD^CVActual enroll code stream.In this case, the QDBits that 3 bits are first represented by the present invention^CVEnroll code stream, then By each Sign^CVAll enroll code stream, by each QD with 1 bit^CVAll use QDBits^CVIndividual bit enrolls code stream, finally by each QP^CVAll use QPBits^CVIndividual bit enrolls code stream.

According to encoding information above, use CH_MODE that current block carries out number of coded bits CBits that coding consumes^CVPress Formula (46) is calculated:

7) self adaptation pointwise pattern (AP_MODE):

In the present invention, current block selects AP_MODE to have two conditions as its effective candidate coding pattern, wherein first Condition is: current block does not comprise coboundary data and the left margin data of current chroma component sub-frame.

This pattern is used to encode, to each initial data P in current block, its predictive value Pred^APBy formula (47) It is calculated.In formula (47), R_LThe reconstruction data of adjacent left-hand position, space, R for P_USpace for P weighs adjacent and above Build data, R_ULReconstruction data for the adjacent top-left position in space of P.Work as R_ULWith R_UDifference amplitude less than or equal to R_ULWith R_LDifference Different amplitude, then show that the horizontal direction dependency rebuilding data is more than vertical direction dependency, and the present invention is by R_LPrediction as P Value, otherwise shows that the vertical direction dependency rebuilding data is more than horizontal direction dependency, and the present invention is by R_UPrediction as P Value.Prediction residual D of P^APBe calculated by formula (48), prediction residual symbol is calculated by formula (49), is quantified residual error QD^APIt is calculated by formula (50), is rebuild data R^APIt is calculated by formula (51).

${\mathrm{Pred}}^{AP}=\left\{\begin{array}{ccc}{R}_L,& if& |R_{UL}-R_U|\&le;|R_{UL}-R_L|\\ R_U& if& |R_{UL}-R_U|>|R_{UL}-R_L|\end{array}\right.---\left(47\right)$

D^AP=P-Pred^AP (48)

${\mathrm{Sign}}^{AP}=\left\{\begin{array}{ccc}0,& if& D^{AP}\&GreaterEqual;0\\ 1,& if& D^{AP}<1\end{array}\right.---\left(49\right)$

QD^AP=(| D^AP|+(QStep ＞ ＞ 1)) ＞ ＞ shift (50)

$R^{AP}=\left\{\begin{array}{ccc}\min ({\mathrm{Pred}}^{AP}+({\mathrm{QD}}^{AP}<<shift),255),& if& {\mathrm{Sign}}^{AP}=0\\ \max ({\mathrm{Pred}}^{AP}-({\mathrm{QD}}^{AP}<<shift),0),& if& {\mathrm{Sign}}^{AP}=1\end{array}\right.---\left(51\right)$

In order to enable decoding end to rebuild each data of current block by formula (51), first must be by the coding of AP_MODE Pattern identification ModeID^APEnroll code stream, ModeID in the present invention^APRepresent with 4 bits, be worth for 0b1110.Decoding end is resolving code After stream obtains the coding mode mark ModeID of current block, when ModeID value is ModeID^AP, then explanation current block uses AP_ MODE encodes, and then obtains each Pred of current block^AP。

Maximum quantization residual error QD then according to current block^AP _maxEach QD is calculated by formula (52)^APEnroll the bit of code stream Number QDBits^AP.In formula (52), work as QD^AP _maxEqual to 0, show all QD of current block^APBe all 0, i.e. current block is AP_MODE Quantify residual error stand growth model, then without consuming each QD of bits of encoded^AP, the present invention is by QDBits^APIt is set to 0；Work as QD^AP _maxMore than 0, The then all QD of current block^APIn the range of [0, QD^AP _max], each QD^APAt least useIndividual bit represents, this Bright by QDBits^APIt is set toIn order to reduce code stream bit number and in view of QDBits^APTypical ranges, The QDBits that the present invention will only represent with 3 bits^APEnroll code stream, QDBits^APAllowed band be [0,7].

Therefore, in the present invention, current block selects the AP_MODE as second condition of its effective candidate coding pattern to be: QDBits^APIt is not more than 7.Work as QDBits^APMore than 7, then cannot be enrolled code stream with 3 bits, AP_MODE in this case The final coding mode of current block cannot be become, be not the most effective candidate coding pattern of current block, after this pattern must being terminated Continuous calculating.

Finally according to QDBits^APSign by each data^APAnd QD^APEnroll code stream: work as QDBits^APEqual to 0, show to work as The QD of front piece^APIt is all 0, Sign^APDo not affect the reconstructed results of formula (51), therefore all Sign in current block^APAnd QD^APThe most not Need to enroll code stream；Work as QDBits^APMore than 0, show that current block exists QD^APMore than 0, therefore the present invention is all of by current block Sign^APAnd QD^APAll enroll code stream, wherein Sign^APWith 1 bit represent, QD^APUse QDBits^APIndividual bit represents.

According to encoding information above, use AP_MODE that current block carries out number of coded bits CBits that coding consumes^APPress Formula (53) is calculated.

8) direct quantitative mode (DQ_MODE):

All data blocks can select this pattern as its effective candidate coding pattern.This pattern is compiled according to present frame Enter the frame level image quality mode PicQ in the frame originating point information of code stream, be divided into following two implementation:

(a) all quantification manners:

In following three kinds of situations, DQ_MODE uses whole quantification manners to realize: (a-1) frame level image quality mode is nothing Damage pattern (the PicQ value of write code stream is 0)；(a-2) frame level image quality mode (writes code stream for damaging clear pattern PicQ value is 1)；(a-3) frame level image quality mode is to damage balanced mode (the PicQ value of write code stream is 2) and current chroma Component sub-frame is U or V component subframe.The concrete methods of realizing of the DQ_MODE whole quantification manners of employing is as follows:

To initial data P each in current block, the present invention is not predicted, and directly uses quantization, the side rebuilding and encoding Formula: first press formula (54) and calculate the quantized data QP of P^DQ1, then press formula (55) calculating reconstruction data R^DQ1, finally press formula (56) Calculate quantization tables of data and show bit number QPBits^DQ1.In order to enable decoding end to rebuild the data of current block by formula (55), this First invention would indicate that the coding mode mark ModeID of DQ_MODE^DQEnroll code stream, represent with 4 bits, be worth for 0b1111；Connect Each QP^DQ1Use QPBits^DQ1Individual bit number enrolls code stream.In the present invention, P represents with 8 bits, and P shifts through formula (54) After quantization, QP^DQ1Only need to 8 subtract shift bit represent can (shift is frame level quantization shift amount), therefore QPBits^DQ1 It is calculated by formula (56).According to formula (56), all QPBits in present frame^DQ1The most equal, the most relevant with shift, and Shift can be obtained by the frame level image quality mode PicQ of encoded code stream, therefore QPBits^DQ1Need not enroll code stream.

QP^DQ1=(P+ (QStep ＞ ＞ 1)) ＞ ＞ shift (54)

R^DQ1=QP^DQ1＜ ＜ shift (55)

QPBits^DQ1=8-shift (56)

According to encoding information above, use whole quantification manners of DQ_MODE that current block carries out the coding that coding consumes Bit number CBits^DQ1It is calculated by formula (57).

CBits^DQ1=4+h × v × QPBits^DQ1 (57)

B () level halves quantification manner:

When frame level image quality mode is to damage balanced mode (the PicQ value of write code stream is 2) and current chroma component Frame is Y-component subframe, then DQ_MODE employing level halves quantification manner and encodes, and concrete methods of realizing is as follows:

Current block first often takes adjacent two data P by order from left to right in the horizontal direction_(2*i,j)And P_(2*i+1,j), Calculate their average as a new data P '_(i,j), as shown in formula (58), i and j is respectively the horizontal level of new data block Index and vertical position index；For being in the data block of chromatic component subframe right margin, if its h is odd number, the most often row is last One P_(2*i,j)There is no paired P_(2*i+1,j), the present invention is directly by P '_(i,j)It is set to P_(2*i,j).Current block is through level side To resolution halve after obtain all P ' form new data block, to data P ' each in new data block, first press formula (59) Calculate its quantized data QP^DQ2, then calculate its reconstruction data R ' by formula (60), finally press formula (61) and calculate corresponding with P ' P_(2*i,j)And P_(2*i+1,j)Two reconstruction data R^DQ2 _(2*i,j)And R^DQ2 _(2*i+1,j)。

P'_(i,j)=(P_(2*i,j)+P_(2*i+1,j)) ＞ ＞ 1 (58)

QP^DQ2=(P'+ (QStep ＞ ＞ 1)) ＞ ＞ shift (59)

R'=QP^DQ2＜ ＜ shift (60)

$\left\{\begin{array}{c}{R}_{(2*i,j)}^{DQ2}=R^{\&prime;}\\ R_{(2*i+1,j)}^{DQ2}=R^{\&prime;}\end{array}\right.---\left(61\right)$

In order to enable decoding end to rebuild the data of current block by formula (60) and (61), the present invention is first by DQ_MODE Coding mode mark ModeID^DQEnroll code stream, represent with 4 bits, be worth for 0b1111；Then by each QP^DQ2Use QPBits^DQ2 Individual bit number enrolls code stream.In the present invention, P represents with 8 bits, and P ' also represents with 8 bits, after formula (59) shift quantization, QP^DQ2Only need to subtract shift bit with 8 to represent, therefore QPBits^DQ2It is calculated by formula (62).According to formula (62), The all of QPBits of present frame^DQ2The most equal, the most relevant with shift, therefore QPBits^DQ2Need not enroll code stream.

QPBits^DQ2=8-shift (62)

According to encoding information above, use the level of DQ_MODE to halve quantification manner and current block is carried out what coding consumed Number of coded bits CBits^DQ2It is calculated by formula (63).

CBits^DQ2=4+ ((h+1) ＞ ＞ 1) × v × QPBits^DQ2 (63)

For the ease of unified presentation, the present invention carries out, by using DQ_MODE, the number of coded bits that coding consumes to current block It is designated as CBits^DQ, according to specific implementation, its value is CBits^DQ1Or CBits^DQ2。

Formula (63) is compared with formula (57), although QPBits^DQ2With QPBits^DQ1Equal, but due to quantized data Number decreases half, significantly reduces number of coded bits.In order to obtain preferable video quality while improving compression ratio, this Invention is all that horizontal resolution is more than vertical resolution in view of typical screen video, therefore DQ_MODE halve quantization side Formula only selects horizontal direction data carry out 1/2nd extractions, and uses the mode taking average in extraction process, reduces The loss of well as subjective video quality.Owing to decoding end can obtain the reality of DQ_MODE according to PicQ and chromatic component subframe type Existing mode, therefore the DQ_MODE implementation of each piece is not enrolled code stream by the present invention, decreases number of coded bits.Multiple Under the switching of miscellaneous screen video scene, the temporal correlation between video data reduces, the candidate coding pattern in addition to DQ_MODE Predictive efficiency significantly reduces, and number of coded bits is more, and DQ_MODE is owing to can use level to halve quantification manner, only to half Video data be compressed, significantly reduce the peak-data amount of video code flow.

In step (5), described effective candidate coding pattern refers to allow the candidate directly as final coding mode Coding mode, for individual data block, the effective candidate coding pattern between data block there are differences.Described continuous blocks Require that the coded sequence of data block is adjacent in current chroma component sub-frame.

Due in step (5), the quantization residual error number of bits (QDBits of all candidate pattern^XX, its subscript XX be IC, Each candidate pattern corresponding is distinguished when HP, VP, CH, CV or AP) to unify to represent with 3 bits, it is simple to decoding end analytic uniform, it is permitted The maximum permitted is 7.In the case of the inter frame image quality of present frame is lossless mode, quantization step is all 1, candidate code There is the QDBits situation more than 7 in pattern IC_MODE, HP_MODE, VP_MODE, CH_MODE, CV_MODE and AP_MODE, Cause them to cannot function as effective candidate coding pattern of current block, i.e. cannot become final coding mode.And DQ_MODE due to Its QPBits^DQ1Or QPBits^DQ2Without enrolling code stream, do not have effective candidate to limit, it is ensured that each piece at least one have Effect candidate coding pattern, it is to avoid occur not having coding mode can situation.

In step (5), candidate coding pattern HP_MODE, VP_MODE, CH_MODE, CV_MODE and AP_MODE are at meter When calculating coding information, all each data in current block are employed to rebuild the mode predicted, i.e. space adjacent Rebuild data using the predictive value as current data.

In step (5), the binary value of each coding mode mark is not mutually equal for prefix, decimal value, and And under exemplary screen video scene, final coding mode adds up the ratio less number of bits table of higher pattern identification Show, effectively reduce the total bit number of coding, as shown in table 3.

Table 3

Coding mode identifies	Decimal value	Number of bits	Binary value
				ModeID<sup>IC</sup>	0	2	0b00
ModeID<sup>SO</sup>	1	2	0b01
				ModeID<sup>HP</sup>	4	3	0b100
ModeID<sup>VP</sup>	5	3	0b101
				ModeID<sup>CH</sup>	12	4	0b1100
ModeID<sup>CV</sup>	13	4	0b1101
				ModeID<sup>AP</sup>	14	4	0b1110
ModeID<sup>DQ</sup>	15	4	0b1111

In step (5), current block can from its effective candidate coding pattern an optional pattern directly as finally Coding mode.In order to improve video compress ratio, reduce the computation complexity of model selection and obtain good video image quality, Can coding mode preferably final with sub-step by the following method:

If (5-1) SO_MODE is effective candidate coding pattern of current block or is the consecutive identical list started from current block Effective candidate coding pattern of value block, then directly finally encode mould as current block or the continuous blocks that start from current block Formula, and the data set of rebuilding under this pattern is become the final reconstructed block of correspondence position, and termination pattern selects in advance；Otherwise hold Go next step.

If (5-2) IC_MODE is effective candidate coding pattern of current block and current block exists non-zero quantised residual error, then count Calculate the bit number CBits that current block uses this pattern-coding to consume^IC, and perform next step；If IC_MODE is having of current block The quantization residual error of effect candidate coding pattern and current block is zero, then detecting subsequent block from next BOB(beginning of block) is the most also IC_ MODE quantifies residual error stand growth model, until quantization residual error non-full zero block or last block being detected, and directly by IC_MODE As current block or the final coding mode of continuous blocks that starts from current block, the reconstruction data set under this pattern is become corresponding position Put final reconstructed block, and in advance termination pattern select；Other situation performs next step.

(5-3) the coding information using HP_MODE that current block is predicted quantization is calculated；If HP_MODE is current block Effective candidate coding pattern and current block there is non-zero quantised residual error, then calculate current block and use this pattern-coding to consume Bit number CBits^HP, and perform next step；If the quantization of effective candidate coding pattern that HP_MODE is current block and current block is residual Difference is zero, then directly as the final coding mode of current block, and the reconstruction data under this pattern are formed current block Final reconstructed block, and in advance terminate current block model selection；Other situation performs next step.

(5-4) the coding information using VP_MODE that current block is predicted quantization is calculated；If VP_MODE is current block Effective candidate coding pattern and current block there is non-zero quantised residual error, then calculate current block and use this pattern-coding to consume Bit number CBits^VP, and perform next step；If the quantization of effective candidate coding pattern that VP_MODE is current block and current block is residual Difference is zero, then directly as the final coding mode of current block, and the reconstruction data under this pattern are formed current block Final reconstructed block, and in advance terminate current block model selection；Other situation performs next step.

(5-5) the coding information using AP_MODE that current block is predicted quantization is calculated；If AP_MODE is current block Effective candidate coding pattern and current block there is non-zero quantised residual error, then calculate current block and use this pattern-coding to consume Bit number CBits^AP, and perform next step；If the quantization of effective candidate coding pattern that AP_MODE is current block and current block is residual Difference is zero, then directly as the final coding mode of current block, and the reconstruction data under this pattern are formed current block Final reconstructed block, and in advance terminate current block model selection；Other situation performs next step.

(5-6) it is unsatisfactory for becoming condition or its CBits of the effective candidate coding pattern of current block as HP_MODE^HPMore than threshold Value TH1, first calculates and uses CH_MODE current block to be predicted the coding information quantified, if then CH_MODE meets into For the condition of the effective candidate coding pattern of current block, then calculate and use CH_MODE that current block carries out the ratio that coding needs to consume Special number CBits^CH.The span of TH1 is [6, h × v × QPBits^CH], TH1 is the biggest, and CH_MODE becomes final coding mode Probability the least.Coded system RowMode that current block is often gone under CH_MODE^CHDetermine according to formula (64), its intermediate value Being that 1 expression current line uses direct quantification manner, value is that 0 expression current line uses horizontal forecast quantification manner,Represent current line maximum quantization residual error QD^CH _row-maxThe minimum number of coded bits needed, threshold value TH^CH In the range of [0,7], its value is the least, is more about to select direct quantification manner.

(5-7) it is unsatisfactory for becoming condition or its CBits of the effective candidate coding pattern of current block as VP_MODE^VPMore than threshold Value TH2, first calculates and uses CV_MODE current block to be predicted the coding information quantified, if then CV_MODE meets into For the condition of the effective candidate coding pattern of current block, then calculate and use CV_MODE that current block carries out the ratio that coding needs to consume Special number CBits^CV.The span of TH2 is [6, h × v × QPBits^CV], TH2 is the biggest, and CV_MODE becomes final coding mode Probability the least.Current block is coded system ColMode of each column under CV_MODE^CVDetermining according to formula (65), its value is 1 represents when prostatitis uses direct quantification manner, and value is that 0 expression vertically predicts quantification manner when prostatitis uses,Represent when prostatitis maximum quantization residual error QD^CV _col-maxThe minimum number of coded bits needed, threshold value TH^CV In the range of [0,7], the least then more row of value will select direct quantification manner.

If (5-8) DQ_MODE of current chroma component sub-frame uses whole quantification manners, then determine to work as according to formula (66) Whether front piece calculate the quantization of DQ_MODE and rebuild data, EN^DQ1Value is quantization and the weight that 1 expression current block calculates DQ_MODE Building data, value is that 0 expression current block does not calculate the quantization of DQ_MODE and rebuilds data, CBits_MINRepresent calculated each pattern Middle coding need to consume the minima of bit number, and shift is that take the logarithm by 2 frame level that obtains of frame level quantization step QStep quantifies to move Position figure place.

If the DQ_MODE use level of current chroma component sub-frame halves quantification manner, i.e. when frame level image quality mode It is Y-component subframe for damaging balanced mode and current chroma component sub-frame, then determines whether current block calculates DQ_ by formula (67) The quantization of MODE and reconstruction data, EN^DQ2Value is that 1 expression current block calculates the quantization of DQ_MODE and rebuilds data, and value is 0 expression Current block does not calculate the quantization of DQ_MODE and rebuilds data；TotalBits_YRepresent the encoding ratio that current Y-component subframe has consumed Special number, η is coefficient of comparisons, and less than 1.0, typical value scope is [0.2,0.8], H₁For the horizontal resolution of Y-component subframe, V₁ Vertical resolution for Y-component subframe.

Current block is after formula (66) or formula (67) judge, if EN^DQ1Or EN^DQ2Value is 1, then calculate current block and use The quantization of DQ_MODE and reconstruction data, and calculate the bit number CBits using DQ_MODE to carry out coding needs consumption^DQ, its value For CBits^DQ1Or CBits^DQ2。

${\mathrm{EN}}^{DQ1}=\left\{\begin{array}{cc}1,& \begin{array}{cc}if& {\mathrm{CBits}}_{MIN}>h\&times;v\&times;(8-shift)\end{array}\\ 0,& others\end{array}\right.---\left(66\right)$

${\mathrm{EN}}^{DQ2}=\left\{\begin{array}{cc}1,& \begin{array}{cc}if& {\mathrm{TotalBits}}_Y>\mathrm{\&eta;}\&times;H_1\&times;V_1\&times;8\end{array}\\ 0,& others\end{array}\right.---\left(67\right)$

(5-9) from the effective candidate coding pattern estimated, final volume is selected by the principle that consumption number of coded bits is minimum Pattern, in the case of number of coded bits is identical, selects the coding mode ident value final coding mode of less conduct；Will be current Block data set of rebuilding under final coding mode becomes the final reconstructed block of correspondence position, and the coding for subsequent block provides prediction ginseng Examine.

Coding information is write code stream according to the final coding mode of current block by described step (6) in order, specifically divides Eight kinds of situations below:

(6-1) the final coding mode of current block is IC_MODE, the most as follows by coding information write code stream:

A coding mode mark ModeID that () write code stream 2 bit represents^IC, its value is 0b00.

B stand growth model mark AZBFlag that () write code stream 1 bit represents^IC。

If (c) AZBFlag^ICValue is 0b1, then show that current block is that IC_MODE quantifies residual error stand growth model, jump to step (f), Otherwise show that current block exists non-zero quantised residual error, perform next step.

D quantization residual error number of bits QDBits that 3 bits are represented by ()^ICWrite code stream.

E () first presses the order of raster scanning by all of for current block prediction residual symbol Sign^ICWrite code stream, each Sign^ICRepresent with 1 bit；The most in the same order by all of for current block quantization residual error QD^ICWrite code stream, each QD^ICWith QDBits^ICIndividual bit represents；At all of Sign^ICAnd QD^ICAfter all writing code stream, terminate the code stream write of current block.

F consecutive identical monodrome block identification ContiFlag that () write code stream 1 bit represents^ICIf: only to single quantization residual error Stand growth model encodes, then ContiFlag^ICValue is 0b0, and terminates the code stream write of current block；If to start from current block ContiCnt continuously^ICIndividual quantization residual error stand growth model encodes, then ContiFlag^ICValue is 0b1, and performs next step.

G () is first by ContiCnt^ICNumber of coded bits mark ContiCntBitsIdx^ICUse 2 bit write code streams, then By ContiCnt^ICThe use ContiCntBits that subtracts 1^ICIndividual bit write code stream, finally terminates the code stream write of current block.Decoding End can pass through ContiCntBitsIdx^ICObtain ContiCntBits^ICIf: ContiCntBitsIdx^ICValue is 0b00, the most right Answer ContiCntBits^ICValue is 2；Work as ContiCntBitsIdx^ICValue is 0b01, then corresponding ContiCntBits^ICValue is 6；If ContiCntBitsIdx^ICValue is 0b10, corresponding ContiCntBits^ICValue is 11；If ContiCntBitsIdx^ICValue is 0b11, Then corresponding ContiCntBits^ICValue is

(6-2) the final coding mode of current block is monodrome raw mode SO_MODE, will encode information the most as follows Write code stream:

A () writes the coding mode mark ModeID that 2 bits represent^SO, its binary value is 0b01.

B () writes monodrome coded system CodPsFlag that 1 bit represents^SO。

If (c) CodPsFlag^SOValue is equal to 0b1, then the single-value data P represented by 8 bits_sWrite code stream；If CodPsFlag^SOValue equal to 0b0, show the final coding mode of the adjacent top coded block in current block space be SO_MODE and Its single-value data and the single-value data P of current block_sEqual, the most not by P_sWrite code stream.

D () writes the consecutive identical monodrome block identification ContiFlag that 1 bit represents^SO。

If (e) ContiFlag^SOValue, equal to 0b0, represents and only encodes current block, then the code stream terminating current block is write Enter；If ContiFlag^SOValue, equal to 0b1, represents the ContiCnt started from current block^SOThe coding mode of individual consecutive data block is all The most equal for SO_MODE and their monodrome, the most first write the ContiCnt that 2 bits represent^SONumber of coded bits identifies ContiCntBitsIdx^SO, then by ContiCnt^SOSubtract 1 and use ContiCntBits^SOIndividual bit represents write code stream.Decoding end can To pass through ContiCntBitsIdx^SOObtain ContiCntBits^SO: work as ContiCntBitsIdx^SOValue is 0b00, then corresponding ContiCntBits^SOValue is 2；Work as ContiCntBitsIdx^SOValue is 0b01, then corresponding ContiCntBits^SOValue is 6；Then when ContiCntBitsIdx^SOValue is 0b10, corresponding ContiCntBits^SOValue is 11；Work as ContiCntBitsIdx^SOValue is 0b11, Then corresponding ContiCntBits^SOValue is

(6-3) the final coding mode of current block is horizontal pointwise pattern HP_MODE, will encode information the most as follows Write code stream:

A coding mode mark ModeID that () write code stream 3 bit represents^HP, its binary value is 0b100.

B quantization residual error number of bits QDBits that () write code stream 3 bit represents^HP。

If (c) QDBits^HPValue is 0, then terminate the code stream write of current block；If QDBits^HPValue, more than 0, the most first presses grating The order of scanning is by all of for current block prediction residual symbol Sign^HPWrite code stream, each Sign^HPRepresent with 1 bit, then press Identical order is by all of for current block quantization residual error QD^HPWrite code stream, each QD^HPUse QDBits^HPIndividual bit represents.

(6-4) the final coding mode of current block is vertical pointwise pattern VP_MODE, the most as follows by current block Coding information write code stream:

A coding mode mark ModeID that () write code stream 3 bit represents^VP, its binary value is 0b101.

B quantization residual error number of bits QDBits that () write code stream 3 bit represents^VP。

If (c) QDBits^VPValue is 0, then terminate the code stream write of current block；If QDBits^VPValue, more than 0, the most first presses grating The order of scanning is by all of for current block prediction residual symbol Sign^VPWrite code stream, each Sign^VPRepresent with 1 bit, then press Identical order is by all of for current block quantization residual error QD^VPWrite code stream, each QD^VPUse QDBits^VPIndividual bit represents.

(6-5) the final coding mode of current block is level of complexity pattern CH_MODE, the most as follows by current block Coding information write code stream:

A () writes the coding mode mark ModeID that 4 bits represent^CH, its binary value is 0b1100.

B () presses order from top to bottom by coded system RowMode of each row of data^CHWrite code stream, often goes RowMode^CHRepresent with 1 bit.

C () is according to RowMode^CHThe distribution of value divides following three kinds of situations to encode:

(c-1) if the RowMode of all write code streams^CHValue is all 0b1, and the data of the most all row all use and directly quantify to compile Code mode, then press the order of raster scanning by all of for current block quantized data QP^CHWrite code stream, each QP^CHUse QPBits^CH Individual bit represents.

(c-2) if writing the RowMode of code stream^CHValue is all 0b0, and the data of the most all row all use horizontal forecast to quantify to compile Code mode, first writes quantization residual error number of bits QDBits represented with 3 bits^CH；If then QDBits^CHMore than 0, then First press the order of raster scanning by all of for current block prediction residual symbol Sign^CHWrite code stream, each Sign^CHWith 1 bit table Show, more in the same order by all of for current block quantization residual error QD^CHWrite code stream, each QD^CHUse QDBits^CHIndividual bit table Show.

(c-3) if writing the RowMode of code stream^CHValue is 0b0 and all existing for 0b1, first writes and to represent with 3 bits Quantify residual error number of bits QDBits^CH；If then QDBits^CHMore than 0, the most first by the order of raster scanning, current block is owned Prediction residual symbol Sign^CHWrite code stream, each Sign^CHRepresent with 1 bit, more in the same order current block is owned Quantization residual error QD^CHWrite code stream, each QD^CHUse QDBits^CHIndividual bit represents；The order finally pressing raster scanning will be current Block all of quantized data QP^CHWrite code stream, each QP^CHUse QPBits^CHIndividual bit represents.

(6-6) the final coding mode of current block is complicated vertically pattern CV_MODE, the most as follows by current block Coding information write code stream:

A () writes the coding mode mark ModeID that 4 bits represent^CV, its binary value is 0b1101.

B () presses order from left to right by each column coded system ColMode^CVWrite code stream, the ColMode of each column^CVAt code Stream represents with 1 bit.

C () is according to ColMode^CVThe distribution of value divides following three kinds of situations to encode:

(c-1) if the ColMode of all write code streams^CVValue is all 0b1, and the data of the most all row all use the directly side of quantization Formula, then press the order of raster scanning by all of quantized data QP^CVWrite code stream, each QP^CVUse QPBits^CVIndividual bit represents.

(c-2) if the ColMode of all write code streams^CVValue is all 0b0, and the data of the most all row all use vertical premeasuring Change mode, first writes quantization residual error number of bits QDBits represented with 3 bits^CV；If then QDBits^CVMore than 0, then First press the order of raster scanning by all of for current block prediction residual symbol Sign^CVWrite code stream, each Sign^CVWith 1 bit table Show, more in the same order by all of for current block quantization residual error QD^CVWrite code stream, each QD^CVUse QDBits^CVIndividual bit table Show.

(c-3) if writing the ColMode of code stream^CVValue is 0b0 and all existing for 0b1, first writes and to represent with 3 bits Quantify residual error number of bits QDBits^CV；If then QDBits^CVMore than 0, the most first by the order of raster scanning, current block is owned Prediction residual symbol Sign^CVWrite code stream, each Sign^CVRepresent with 1 bit, more in the same order current block is owned Quantization residual error QD^CVWrite code stream, each QD^CVUse QDBits^CVIndividual bit represents；The order finally pressing raster scanning will be current Block all of quantized data QP^CVWrite code stream, each QP^CVUse QPBits^CVIndividual bit represents.

(6-7) the final coding mode of current data block is self adaptation pointwise Mode A P_MODE, the most as follows ought The coding information write code stream of front piece:

A coding mode mark ModeID that () write code stream 4 bit represents^AP, its binary value is 0b1110.

B quantization residual error number of bits QDBits that () write code stream 3 bit represents^AP。

If (c) QDBits^APValue is 0, then terminate the code stream write of current block；If QDBits^APValue, more than 0, the most first presses grating The order of scanning is by all of for current block prediction residual symbol Sign^APWrite code stream, each Sign^APRepresent with 1 bit, then press Identical order is by all of for current block quantization residual error QD^APWrite code stream, each QD^APUse QDBits^APIndividual bit represents.

(6-8) the final coding mode of current data block is direct quantitative mode DQ_MODE, the most as follows will coding Information write code stream:

A () writes the coding mode mark ModeID that 4 bits represent^DQ, its binary value is 0b1111.

If b () DQ_MODE uses the coded system all quantified, then press the order of raster scanning by all quantized datas QP^DQ1Write code stream, each QP^DQ1Use QPBits^DQ1Individual bit represents；If DQ_MODE employing level halves the coding staff of quantization Formula, then press the order of raster scanning by all quantized data QP^DQ2Write code stream, each QP^DQ2Use QPBits^DQ2Individual bit represents.

Described step (8) to present frame written into code stream carry out byte-aligned process, concrete grammar is as follows: if current Frame written into the multiple that total bit number TotalBits of code stream is not 8, then fills, toward code stream afterbody, the bit that several values are zero Data, filling number is 8 to deduct rem (rem is the remainder that TotalBits is obtained) by 8 remainders, and code stream becomes word after filling Joint alignment；If the encoded code stream of present frame total bit number TotalBits has been the multiple of 8, it is not filled with.

Described step (8) carries out code stream byte after last data block of each chromatic component subframe has encoded Registration process, it is ensured that the multiple that encoding code stream bit number is 8 of each chromatic component subframe, makes the present invention be embodied as Time support to carry out sub-frame level parallel encoding by three chromatic component subframes, and in order the code stream of three subframes is connected directly between Together, without code stream being carried out integral shift process when code stream connects, improve processing speed.

Described step (10) carries out frame sync identifications escape process to the code stream after present frame frame sync identifications, specifically Method is as follows: to each byte after the frame sync identifications of present frame code stream, reads this byte and 3 bytes thereafter in order Data, form 4 byte datas FourBytes (byte first read is in higher bit position), when FourBytes value is 0xFFFFFFFD, In code stream, then after 0xFD, insert a byte data, be worth for 0x00；When FourBytes value is 0xFFFFFFFE, then by code 0xFE in stream replaces with 0xFD, and inserts a byte data after 0xFD, is worth for 0x01.Decoding end is at present frame code stream First must be last in 0xFFFFFFFD00 by continuous five byte values all in present frame code stream before resolving and rebuilding Individual byte 0x00 is deleted, and is that in 0xFFFFFFFD01, the 4th byte 0xFD replaces with 0xFE by all continuous five byte values, and Last byte 0x01 is deleted.

Numeral KVM switcher carries out compression coding to the screen video of computer export, with under the limited network bandwidth Realize the quick transmission of screen video.The present invention designs candidate coding pattern under the feature taking into full account screen video, is having The compression efficiency of screen video is improved under the computation complexity of limit.For the complete phase of the pixel value of split screen in the middle part of screen video With, the present invention devises monodrome raw mode, supports that monodrome block identical to continuous print carries out Unified coding；In order to improve picture gradually The compression efficiency become, the present invention devises horizontal pointwise pattern and vertical pointwise pattern；In order to improve the pressure of complex texture picture Contracting efficiency, the present invention devises adaptive prediction pattern, level of complexity pattern and the vertical pattern of complexity；In order to improve sudden change picture Compression efficiency, the present invention devises direct quantitative mode；In order to improve the compression efficiency of still frame, the present invention devises frame Between associative mode, support to quantify residual error force zero setting, and to continuous print quantify residual error stand growth model carry out Unified coding.

The video-frequency compression method of the present invention is applicable to the screen video of numeral KVM switcher collection is carried out data compression. Compared with prior art, the present invention has a following beneficial effect:

1) supporting that the classification rebuilding video quality can configure, user can select flexibly according to application demand.

2) each exemplary screen video scene is had preferable compression efficiency, keep good reconstruction video quality simultaneously.

3) the peak-data amount of the lower video code flow of complex screen video scene switching is significantly reduced.

4) overall calculation complexity is low, is suitable on flush bonding processor realizing, effectively reduces the reality of numeral KVM switcher Ready-made and process time delay.

Accompanying drawing explanation

Fig. 1 is the basic flow sheet of the inventive method；

Fig. 2 is the code flow structure figure of frame originating point information, and current code stream represents that the image resolution ratio of present frame is 1366 × 768, Chrominance space form is YUV420, and block divides employing 8 × 4 partition mode, and inter prediction enables closes, and uses and damages balanced mode Compression, is the 1st coded frame；

Fig. 3 is the data block division figure of chromatic component subframe.

Detailed description of the invention

The detailed description of the invention of the present invention is described below in conjunction with the accompanying drawings, it is noted that below for resolution with example Be 1366 × 768 screen video carry out data compression, in the concrete ablation process of compressed bit stream, the present embodiment is deposited by big end Storage pattern writes, and the high-bit data of data to be compressed preferentially writes the higher bit position of code stream byte, the mode of description Simply one of numeral typical application mode of KVM switcher.Within the scope of the invention, those skilled in the art can also root Some other alternate embodiments is used according to demand.

A kind of screen video compression method towards numeral KVM switcher, as it is shown in figure 1, comprise the following steps:

(1) frame screen video data are inputted:

A described frame screen video data from digital KVM switcher collects, and in the present embodiment, the screen of input regards Frequency is according to using YUV chrominance space, and image resolution ratio is 1366 × 768 (i.e. horizontal resolutions H of image₀It is 1366, vertically divides Resolution is V₀It is 768), comprise 1049088 pixels altogether.In order to reduce the compressed code fluxion of high-resolution screen video as far as possible According to amount, the chrominance space form that the present embodiment is selected is YUV420, and its relatively YUV422 and YUV444 has less U component data With V component data.Current video frame is divided into three chromatic component subframes, all Y-component data composition H₁×V₁2-D data Array, is designated as Y-component subframe, its horizontal resolution H₁Equal to 1366, vertical resolution V₁Equal to 768；All U component data groups Become H₂×V₂Two-dimensional data array, be designated as U component sub-frame, according to table 1, its horizontal resolution H₂Equal to 683, vertical resolution V₂Equal to 384；All V component data composition H₃×V₃Two-dimensional data array, be designated as V component subframe, according to table 1, its level is divided Resolution H₃Equal to 683, vertical resolution V₃Equal to 384.

(2) frame originating point information of current video frame is write in the following order code stream:

(2-1) writing frame sync identifications SyncF of 4 bytes at byte-aligned, first three byte value is 0xFF, the 4th Individual byte value is 0xFE.

(2-2) the resolution mark PicR of the current screen video image that write represents with 6 bits.The screen of the present embodiment Video resolution is 1366 × 768, and according to table 2 in summary of the invention, PicR value is 0b001111.

(2-3) the chrominance space format identification (FID) ColorF represented with 3 bits is write.The chrominance space form of the present embodiment is YUV420 form, ColorF value is 0b000.

(2-4) the data block partition mode mark BP that write represents with 4 bits_MODE.In order at Current high resolution screen Obtaining preferable compression efficiency under video, the present embodiment selects 8 × 4 partition modes, BP_MODEValue is 0b0001.

(2-5) the write inter prediction that 1 bit represents enables mark TP_EN.Present frame is first coded frame, does not permits Being permitted to use time domain prediction, the present embodiment is by TP_ENIt is set to 0b0；Present frame is not first coded frame, then allow to use time domain pre- Surveying, in order to improve the compression efficiency of screen video, the present embodiment all allows to use inter prediction, TP_ENValue is 0b1.

(2-6) the frame level image quality mode PicQ represented with 2 bits is write.Regard to reduce high-resolution screen as far as possible The bit stream data amount of frequency, the present embodiment selection frame level image quality mode is for damaging balanced mode, and PicQ value is 0b10.

(2-7) the frame number FrameN of the present frame that write represents with 16 bits.Present frame is the first frame, then FrameN value It is 0.The follow-up frame that often encodes, FrameN value adds 1, when FrameN is equal to 65536, FrameN the most first resets to 0, then will FrameN writes code stream.

In step (2), each numerical value be its high order bit first write code stream (first pass through network and be sent to decoding end), Code stream is write after low-order bit.Each bit priority, during write code stream, is write a storage byte by the present embodiment Higher bit position.Fig. 2 show the present embodiment and uses the preamble information bitstream structure chart under big end memory module.

(3) from current video frame, a uncoded color is obtained by Y-component subframe, U component sub-frame, the order of V component subframe Degree component sub-frame as current chroma component sub-frame, 8 × 4 partition modes selected according to step (2) to present sub-frame by grating The order of scanning carries out data block division, calculates data block number H in present sub-frame horizontal direction by formula (1)_blk, by public affairs Formula (2) calculates data block number V on present sub-frame vertical direction_blk, calculate data to be encoded block in this subframe by formula (3) Total number N_blk.In the present embodiment, the concrete data block of three chromatic component subframes divides as it is shown on figure 3, the resolution of Y-component subframe Rate is 1366 × 768,171 blocks of horizontal direction, 192 blocks of vertical direction, totally 32832 blocks；U component sub-frame and V component The resolution of frame is all 683 × 384, and horizontal direction has 86 blocks, and vertical direction has 96 blocks, and whole subframe is respectively arranged with 8256 Individual block.

(4) from current chroma component sub-frame, a uncoded data block is obtained as current block:

From current chroma component sub-frame, the two-dimemsional number to be encoded of h × v size is obtained by the order of raster scanning According to block.According to the BP of write code stream in step (2)_MODEObtain data block dividing unit, BP in the present embodiment_MODEValue is 0b0001, Data block dividing unit is 8 × 4, the data amount check h that corresponding horizontal direction divides_PIt is 8, the number that corresponding vertical direction divides According to number v_PIt is 4.In Y-component subframe, the block size comprising right margin be 6 × 4 (h equal to 6, v equal to 4), other block big Little is all basic to divide size 8 × 4 (h equal to 8, v equal to 4)；In U component sub-frame, the block size comprising right margin is 3 × 4 (h equal to 3, v equal to 4), the size of other block be all basic division size 8 × 4；In V component subframe, comprise the block of right margin Size be 3 × 4 (h equal to 3, v equal to 4), the size of other block be all basic division size 8 × 4.

(5) calculate current block coding information under each effective candidate coding pattern and rebuild data, and choosing final Coding mode and reconstruction data.In order to improve video compress ratio, reduce the computation complexity of model selection and obtain good regarding Frequently picture quality, the present embodiment carries out model selection with method according to the following steps, with the most final coding mode, and obtains final Reconstruction data:

If (5-1) SO_MODE is effective candidate coding pattern of current block or is the consecutive identical list started from current block Effective candidate coding pattern of value block, then directly finally encode mould as current block or the continuous blocks that start from current block Formula, and the data set of rebuilding under this pattern is become the final reconstructed block of correspondence position, and termination pattern selects in advance.

If (5-2) IC_MODE is effective candidate coding pattern of current block and current block exists non-zero quantised residual error, then press Formula (13) calculates the bit number CBits that current block uses this pattern-coding to consume^IC；If IC_MODE is the effective of current block The quantization residual error of candidate coding pattern and current block is zero, then detecting subsequent block from next BOB(beginning of block) is the most also IC_ MODE quantifies residual error stand growth model, until quantization residual error non-full zero block or last block being detected, and directly by IC_MODE As current block or the final coding mode of continuous blocks that starts from current block, the reconstruction data set under this pattern is become corresponding position Put final reconstructed block, and in advance termination pattern select；

If (5-3) HP_MODE is effective candidate coding pattern of current block and current block exists non-zero quantised residual error, then press Formula (22) calculates the bit number CBits that current block uses this pattern-coding to consume^HP；If HP_MODE is the effective of current block The quantization residual error of candidate coding pattern and current block is zero, then directly as the final coding mode of current block, and will The reconstructed block of the reconstruction data composition current block under this pattern, and termination pattern selects in advance.

If (5-4) VP_MODE is effective candidate coding pattern of current block and current block exists non-zero quantised residual error, then press Formula (28) calculates the bit number CBits that current block uses this pattern-coding to consume^VP；If VP_MODE is the effective of current block The quantization residual error of candidate coding pattern and current block is zero, then directly as the final coding mode of current block, and will The reconstructed block of the reconstruction data composition current block under this pattern, and termination pattern selects in advance.

If (5-5) AP_MODE is effective candidate coding pattern of current block and current block exists non-zero quantised residual error, then press Formula (53) calculates the bit number CBits that current block uses this pattern-coding to consume^AP；If AP_MODE is the effective of current block The quantization residual error of candidate coding pattern and current block is zero, then directly as the final coding mode of current block, and will The reconstructed block of the reconstruction data composition current block under this pattern, and termination pattern selects in advance.

If (5-6) HP_MODE is unsatisfactory for becoming requirement or its CBits of the effective candidate coding pattern of current block^HPIt is more than TH1, first calculates and uses CH_MODE that current block is predicted the coding information quantified, and becomes if then CH_MODE is satisfied The condition of the effective candidate coding pattern of current block, then use CH_MODE to carry out current block encoding needs by formula (37) calculating The bit number CBits consumed^CH.In the present embodiment, TH1 takes h × v × QPBits^CH/2；The volume that current block is often gone under CH_MODE Code mode RowMode^CHDetermine according to formula (64), the TH of formula (64) in the present embodiment^CHTake 4.

If (5-7) VP_MODE is unsatisfactory for becoming requirement or its CBits of the effective candidate coding pattern of current block^VPIt is more than TH2, first calculates and uses VP_MODE that current block is predicted the coding information quantified, and becomes if then VP_MODE is satisfied The condition of the effective candidate coding pattern of current block, then use CV_MODE to carry out current block encoding needs by formula (46) calculating The bit number CBits consumed^CV.In the present embodiment, TH2 takes h × v × QPBits^CV/2；Current block is the volume of each column under CV_MODE Code mode ColMode^CVDetermine according to formula (65), the TH of formula (65) in the present embodiment^CVTake 6.

If (5-8) DQ_MODE uses whole quantification manners, then determine whether current block calculates DQ_MODE by formula (66) Quantization and rebuild data, the present embodiment takes coefficient of comparisons η in formula (66) and is taken as 0.5；If the DQ_MODE use level amount of halving By formula (67), change mode, then determine whether current block calculates the quantization of DQ_MODE and rebuild data.Current block is through formula (66) or formula (67) judge after, if EN^DQ1Or EN^DQ2Value is 1, then need calculate the quantization of DQ_MODE and rebuild data, and press Formula (57) or (63) calculate and use DQ_MODE that current block carries out the bit number CBits that coding needs to consume^DQ, its value is CBits^DQ1Or CBits^DQ2。

(5-9) from the effective candidate coding pattern estimated, final volume is selected by the principle that consumption number of coded bits is minimum Pattern, in the case of number of coded bits is identical, selects the coding mode ident value final coding mode of less conduct；Will be final Data set of rebuilding under coding mode becomes the final reconstructed block of correspondence position, and the coding for subsequent block provides prediction reference.

(6) according to the final coding mode of current block, the coding information of current block is write code stream, specifically divide following eight kinds Situation:

If (6-1) the final coding mode of current block is IC_MODE, the most as follows by coding information write code stream:

A coding mode mark ModeID that () write code stream 2 bit represents^IC, its value is 0b00.

B stand growth model mark AZBFlag that () write code stream 1 bit represents^IC。

If (c) AZBFlag^ICValue is 0b1, then show that current block is to quantify residual error stand growth model, jump to step (f), otherwise table There is quantization residual error non-zero in bright current block, performs next step.

D quantization residual error number of bits QDBits that 3 bits are represented by ()^ICWrite code stream.

E () first presses the order of raster scanning by all of for current block prediction residual symbol Sign^ICWrite code stream, each Sign^ICRepresent with 1 bit；The most in the same order by all of for current block quantization residual error QD^ICWrite code stream, each QD^ICWith QDBits^ICIndividual bit represents；At all of Sign^ICAnd QD^ICAfter all writing code stream, terminate the code stream write of current block.

F consecutive identical monodrome block identification ContiFlag that () write code stream 1 bit represents^IC。

If (g) ContiFlag^ICValue is 0b0, represents and encodes single quantization residual error stand growth model, then terminates current block Coding.If ContiFlag^ICValue is 0b1, represents the ContiCnt started from current block^ICThe coding mode of individual consecutive data block Be all IC_MODE and all be quantify residual error stand growth model, the most first by ContiCnt^ICNumber of coded bits mark ContiCntBitsIdx^ICUse 2 bit write code streams, then by ContiCnt^ICThe use ContiCntBits that subtracts 1^ICIndividual compare feature Enter code stream.

If (6-2) the final coding mode of current block is monodrome raw mode SO_MODE, the most as follows coding is believed Breath write code stream:

A () writes the coding mode mark ModeID that 2 bits represent^SO。

B () writes monodrome coded system CodPsFlag that 1 bit represents^SO。

If (c) CodPsFlag^SOValue is equal to 0b1, then the single-value data P represented by 8 bits_sWrite code stream；If CodPsFlag^SOValue equal to 0b0, show the final coding mode of the adjacent top coded block in current block space be SO_MODE and Its single-value data and the single-value data P of current block_sEqual, the most not by P_sWrite code stream.

D () writes the consecutive identical monodrome block identification ContiFlag that 1 bit represents^SO。

If (e) ContiFlag^SOValue, equal to 0b0, represents and only encodes current block, then terminate the coding of current block；If ContiFlag^SOValue, equal to 0b1, represents the ContiCnt started from current block^SOThe coding mode of individual consecutive data block is all SO_ MODE and their monodrome are the most equal, the most first write the ContiCnt that 2 bits represent^SONumber of coded bits identifies ContiCntBitsIdx^SO, then by ContiCnt^SOSubtract 1 and use ContiCntBits^SOIndividual bit represents write code stream.

If (6-3) the final coding mode of current block is horizontal pointwise pattern HP_MODE, the most as follows coding is believed Breath write code stream:

A coding mode mark ModeID that () write code stream 3 bit represents^HP。

B quantization residual error number of bits QDBits that () write code stream 3 bit represents^HP。

If (c) QDBits^HPValue is 0, then terminate the code stream write of current block；If QDBits^HPValue, more than 0, the most first presses grating The order of scanning is by all of for current block prediction residual symbol Sign^HPWrite code stream, each Sign^HPRepresent with 1 bit, then press Identical order is by all of for current block quantization residual error QD^HPWrite code stream, each QD^HPUse QDBits^HPIndividual bit represents.

If (6-4) the final coding mode of current block is vertical pointwise pattern VP_MODE, the most as follows by current block Coding information write code stream:

A coding mode mark ModeID that () write code stream 3 bit represents^VP, its binary value is 0b101.

B quantization residual error number of bits QDBits that () write code stream 3 bit represents^VP。

If (c) QDBits^VPValue is 0, then terminate the code stream write of current block；If QDBits^VPValue, more than 0, the most first presses grating The order of scanning is by all of for current block prediction residual symbol Sign^VPWrite code stream, each Sign^VPRepresent with 1 bit, then press Identical order is by all of for current block quantization residual error QD^VPWrite code stream, each QD^VPUse QDBits^VPIndividual bit represents.

If (6-5) the final coding mode of current block is level of complexity pattern CH_MODE, the most as follows by current block Coding information write code stream:

A () writes the coding mode mark ModeID that 4 bits represent^CH。

B () presses order from top to bottom by coded system RowMode of each row of data^CHWrite code stream, often goes RowMode^CHRepresent with 1 bit.

C () is according to RowMode^CHThe distribution of value divides following three kinds of situations to encode:

(c-1) if the RowMode of all write code streams^CHValue is all 0b1, then owned by current block by the order of raster scanning Quantized data QP^CHWrite code stream, each QP^CHUse QPBits^CHIndividual bit represents.

(c-2) if writing the RowMode of code stream^CHValue is all 0b0, first writes the quantization residual error ratio represented with 3 bits Special figure place QDBits^CH；If then QDBits^CHMore than 0, the most first press the order of raster scanning by all of for current block prediction residual Symbol Sign^CHWrite code stream, each Sign^CHRepresent with 1 bit, then press the order of raster scanning by all of for current block quantization Residual error QD^CHWrite code stream, each QD^CHUse QDBits^CHIndividual bit represents.

(c-3) if writing the RowMode of code stream^CHValue is 0b0 and all existing for 0b1, first writes and to represent with 3 bits Quantify residual error number of bits QDBits^CH；If then QDBits^CHMore than 0, the most first by the order of raster scanning, current block is owned Prediction residual symbol Sign^CHWrite code stream, each Sign^CHRepresent with 1 bit, then press the order of raster scanning by current block All of quantization residual error QD^CHWrite code stream, each QD^CHUse QDBits^CHIndividual bit represents；The order finally pressing raster scanning will Current block all of quantized data QP^CHWrite code stream, each QP^CHUse QPBits^CHIndividual bit represents.

If (6-6) the final coding mode of current block is complicated vertically pattern CV_MODE, the most as follows by current block Coding information write code stream:

A () writes the coding mode mark ModeID that 4 bits represent^CV。

B () presses order from left to right by each column coded system ColMode^CVWrite code stream, the ColMode of each column^CVAt code Stream represents with 1 bit.

C () is according to ColMode^CVThe distribution of value divides following three kinds of situations to encode:

(c-1) if the ColMode of all write code streams^CVValue is all 0b1, then press the order of raster scanning by all of quantization Data QP^CVWrite code stream, each QP^CVUse QPBits^CVIndividual bit represents.

(c-2) if the ColMode of all write code streams^CVValue is all 0b0, and the quantization that first write represents with 3 bits is residual Difference number of bits QDBits^CV；If then QDBits^CVMore than 0, the most first press the order of raster scanning by all of for current block prediction Sign of the residues Sign^CVWrite code stream, each Sign^CVRepresent with 1 bit, more in the same order by all of for current block quantization Residual error QD^CVWrite code stream, each QD^CVUse QDBits^CVIndividual bit represents.

(c-3) if writing the ColMode of code stream^CVValue is 0b0 and all existing for 0b1, first writes and to represent with 3 bits Quantify residual error number of bits QDBits^CV；If then QDBits^CVMore than 0, the most first by the order of raster scanning, current block is owned Prediction residual symbol Sign^CVWrite code stream, each Sign^CVRepresent with 1 bit, more in the same order current block is owned Quantization residual error QD^CVWrite code stream, each QD^CVUse QDBits^CVIndividual bit represents；The order finally pressing raster scanning will be current Block all of quantized data QP^CVWrite code stream, each QP^CVUse QPBits^CVIndividual bit represents.

If (6-7) the final coding mode of current data block is self adaptation pointwise Mode A P_MODE, the most as follows will The coding information write code stream of current block:

A coding mode mark ModeID that () write code stream 4 bit represents^AP。

B quantization residual error number of bits QDBits that () write code stream 3 bit represents^AP。

If (c) QDBits^APValue is 0, then terminate the code stream write of current block；If QDBits^APValue, more than 0, the most first presses grating The order of scanning is by all of for current block prediction residual symbol Sign^APWrite code stream, each Sign^APRepresent with 1 bit, then press Identical order is by all of for current block quantization residual error QD^APWrite code stream, each QD^APUse QDBits^APIndividual bit represents.

If (6-8) the final coding mode of current data block is direct quantitative mode DQ_MODE, will compile the most as follows Code information write code stream:

A () writes the coding mode mark ModeID that 4 bits represent^DQ。

If b () DQ_MODE uses the implementation all quantified, then press the order of raster scanning by all quantized datas QP^DQ1Write code stream, each QP^DQ1Use QPBits^DQ1Individual bit represents；If DQ_MODE uses the implementation halving quantization, then By the order of raster scanning by all quantized data QP^DQ2Write code stream, each QP^DQ2Use QPBits^DQ2Individual bit represents.

(7) repeat step (4) to (6), complete coding and the reconstruction of all data blocks in current chroma component sub-frame.

(8) to current video frame written into code stream carry out bit padding to realize byte-aligned: if present frame written into Total bit number TotalBits of code stream is not the multiple of 8, then toward code stream afterbody filling bit 0, filling number is 8 to deduct rem (rem is the remainder that TotalBits is obtained by 8 remainders), code stream becomes byte-aligned after filling；If the encoded code of present frame Flowing total bit number TotalBits is the multiple of 8, does not the most carry out bit padding.

(9) repeat step (3) to (8), complete coding and the reconstruction of all chromatic component subframes in current video frame.

(10) code stream producing current video frame carries out frame synchronization head escape process, exports final compressed bit stream: right Each byte after the frame sync identifications of present frame code stream, reads the data of this byte and 3 bytes thereafter in order, forms 4 (byte first read is placed on the higher bit bit byte of FourBytes to byte data FourBytes, i.e. by big end pattern composition FourBytes), when FourBytes value is 0xFFFFFFFD, then in code stream, after 0xFD, insert a byte data, be worth and be 0x00；When FourBytes value is 0xFFFFFFFE, then the 0xFE in code stream is replaced with 0xFD, and after 0xFD, inserts one Individual byte data, is worth for 0x01；The code stream of current video frame exports its final compressed bit stream after escape processes.

Claims (21)

1. the screen video compression method towards numeral KVM switcher, it is characterised in that comprise the following steps:

(1) frame screen video data are inputted:

Described frame screen video data refer to that the frame that KVM switcher gathers uses the screen video figure of YUV chrominance space Picture, the pixel resolution of this two field picture is H₀×V₀, it is divided into three chromatic component subframes, all Y-component data composition H₁×V₁ Y-component subframe, all U component datas composition H₂×V₂U component sub-frame, all V component data composition H₃×V₃V component Subframe；

(2) frame originating point information of current video frame being write code stream, described frame originating point information includes:

The frame synchronization leader of 4 byte representations knows SyncF, and first three byte value is 0xFF, and the 4th byte value is 0xFE；

The resolution mark PicR of the present frame screen video image that 6 bits represent, its span is 1 to 24, Mei Gequ Digital kvm system screen video image horizontal resolution H that value is corresponding₀With vertical resolution V₀As follows；

The chrominance space format identification (FID) ColorF that 3 bits represent, characterizes the chrominance space form that current video frame specifically uses, Value represents employing YUV420 form for 0b000, is worth and represents employing YUV422 form for 0b001, is worth and represents employing for 0b010 YUV444 form, 5 numerical value of reserved 0b011 to 0b111；

The data block partition mode mark BP that 4 bits represent_MODE, characterize and each chromatic component subframe carried out data block division Ultimate unit h_p×v_p, it is worth and represents employing 4 × 4 partition mode for 0b0000, be worth and represent that employing 8 × 4 divides mould for 0b0001 Formula, is worth and represents employing 4 × 8 partition mode for 0b0010, is worth and represents employing 8 × 8 partition mode for 0b0011, reserved from 0b0100 12 numerical value to 0b1111；

The inter prediction enable mark TP that 1 bit represents_EN, its value is that 0b0 represents that the coding of present frame does not allow to use interframe Prediction, its value is that 0b1 represents that the coding of present frame allows to use inter prediction；

The frame level image quality mode PicQ that 2 bits represent, characterizes the subjective quality grade of present frame coding and rebuilding image, its Value represents lossless mode for 0b00, is worth and represents for 0b01 and damage clear pattern, is worth and represents for 0b10 and damage balanced mode, reserved 0b11；If present frame uses lossless mode, then its frame level quantization step QStep value is 1；If present frame uses and damages clear mould Formula, then its frame level quantization step QStep value is 2；If present frame uses and damages balanced mode, then its frame level quantization step is QStep value is 4；It is that QStep takes the logarithm by 2 the integer obtained that the frame level of present frame quantifies shift amount shift；

The frame number FrameN that 16 bits represent；

(3) from current video frame, one uncoded chromatic component subframe of acquisition is as current chroma component sub-frame, by current color Degree component sub-frame is divided into the two-dimensional rectangle data block to be encoded of multiple h × v size, and calculates total number of its data block N_blk；

(4) from current chroma component sub-frame, a uncoded two-dimensional rectangle data block work is obtained by from the order of raster scanning For current block；

(5) calculate current block coding information under each candidate coding pattern and rebuild data, and from effective candidate code mould Formula is chosen final coding mode and finally rebuilds data；

(6) according to the final coding mode of current block, the coding information of current block is write code stream；

(7) repeat step (4) to (6) and complete coding and the reconstruction of all data blocks in current chroma component sub-frame；

(8) to current video frame written into code stream carry out bit padding to realize byte-aligned；

(9) repeat step (3) to (8) and complete coding and the reconstruction of all chromatic component subframes in current video frame；

(10) code stream producing current video frame carries out frame synchronization head escape process, exports final compressed bit stream.

2. screen video compression method as claimed in claim 1, it is characterised in that in described step (2), frame originating point information is by such as Under be sequentially written in code stream:

(2-1) at byte-aligned, frame sync identifications SyncF is write；

(2-2) write image resolution ratio mark PicR；

(2-3) write chrominance space format identification (FID) ColorF；

(2-4) writing data blocks partition mode mark BP_MODE；

(2-5) write inter prediction enables mark TP_EN；

(2-6) write frame level image quality mode PicQ；

(2-7) write frame number FrameN.

3. screen video compression method as claimed in claim 1, it is characterised in that described step (3) comprises the steps of:

(3-1) first uncoded chromatic component is obtained by Y-component subframe, U component sub-frame, the order of V component subframe Frame, H_kAnd V_kBe respectively current chroma component sub-frame in the horizontal direction with the data amount check on vertical direction, k is that current chroma divides The index of quantum frame, k value is 1 expression Y-component subframe, and k value is 2 expression U component sub-frame, and k value is 3 expression V component subframes；

(3-2) then according to BP_MODEObtain data block and divide ultimate unit h_P×v_P, h_PThe data amount check divided for horizontal direction, v_PThe data amount check divided for vertical direction；

(3-3) then ultimate unit h is divided according to data block_P×v_PBy the order of raster scanning, current chroma component sub-frame is drawn Being divided into the two-dimensional rectangle data block to be encoded of multiple h × v size, h and v is respectively the data block through dividing in the horizontal direction Data amount check above and on vertical direction；

(3-4) data block number H of current chroma component sub-frame horizontal direction finally it is calculated by formula (1)_blk, by formula (2) data block number V of current chroma component sub-frame vertical direction it is calculated_blk, it is calculated current chroma by formula (3) Total number N of data block of component sub-frame_blk:

N_blk=H_blk×V_blk (3)。

4. screen video compression method as claimed in claim 1, it is characterised in that the candidate code mould in described step (5) Formula includes interframe associative mode IC_MODE:

This pattern is used to encode, for each initial data P in current block, its predictive value Pred^ICFor previous coded frame In identical chromatic component subframe and the reconstruction data of same spatial location, its prediction residual D^ICIt is calculated by formula (4), is predicted Sign of the residues Sign^ICIt is calculated by formula (5), is quantified residual error QD^ICCalculate by formula (6), formula (7) and formula (8) To, rebuild data R^ICIt is calculated by formula (9)；In formula (5), Sign^ICValue be the symbol of 0 expression prediction residual for just, Value be the symbol of 1 expression prediction residual be negative；In formula (6), QD^IC _TmpQuantify residual error for IC_MODE, it calculates process temporarily The quantization step QStep2 that halves used is calculated by formula (8), halves shift amount shift2 and is taken the logarithm by 2 by QStep2 It is calculated；In formula (7), work as QD^ICValue is 1 and QStep2 value when being 2, by QD^ICPressure is set to 0, QD in the case of other^IC Keep constant；In formula (8), QStep is frame level quantization step；

D^IC=P-Pred^IC (4)

${\mathrm{Sign}}^{IC}=\left\{\begin{array}{ccc}0,& if& D^{IC}\&GreaterEqual;0\\ 1,& if& D^{IC}<0\end{array}\right.---\left(5\right)$

${\mathrm{QD}}_{Tmp}^{IC}=\left(\right|D^{IC}|+(QStep2>>1\left)\right)>>shift2---\left(6\right)$

$QStep2=\left\{\begin{array}{cc}QStep>>1,& \begin{array}{cc}if& QStep>1\end{array}\\ 1,& others\end{array}\right.---\left(8\right)$

$R^{IC}=\left\{\begin{array}{ccc}\min ({\mathrm{Pred}}^{IC}+({\mathrm{QD}}^{IC}<<shift2),255),& if& {\mathrm{Sign}}^{IC}=0\\ \max ({\mathrm{Pred}}^{IC}-({\mathrm{QD}}^{IC}<<shift2),0),& if& {\mathrm{Sign}}^{IC}=1\end{array}\right.---\left(9\right)$

Use this pattern to encode, need further exist for enrolling following coding information code stream:

The IC_MODE coding mode mark ModeID that 2 bits represent^IC, its value is 0b00；

The stand growth model mark AZFlag that 1 bit represents^IC, its value is 0b0, represents that current block exists non-zero QD^IC, its value is 0b1, Represent the QD of current block^ICIt is all zero；

The each QD of current block that 3 bits represent^ICNumber of coded bits QDBits^IC, this coding information only need to be at AZFlag^ICValue Enrolling code stream during for 0b0, its value is calculated by formula (10), QD in formula^IC _maxFor all QD of current block^ICIn maximum；

The Sign that 1 bit represents^ICAnd QDBits^ICThe QD that individual bit represents^IC, all Sign of current block^ICAnd QD^ICOnly need to be QDBits^ICCode stream is enrolled during more than 0；

The consecutive identical monodrome block identification ContiFlag that 1 bit represents^IC, its value is that 0b0 represents and only carries out current stand growth model Coding, its value is that 0b1 represents the continuous ContiCnt started from current block^ICIndividual stand growth model encodes, and this coding information is only Need to be at AZFlag^ICCode stream is enrolled when value is for 0b1；

ContiCntBits^ICThe ContiCnt that individual bit represents^ICValue after subtracting 1, wherein ContiCntBits^ICBy formula (11) Being calculated, this coding information only need to be at ContiFlag^ICCode stream is enrolled when value is for 0b1；

The ContiCntBits that 2 bits represent^ICCode identification ContiCntBitsIdx^IC, ContiCntBitsIdx^ICBy public affairs Formula (12) is calculated, and this coding information only need to be at ContiFlag^ICCode stream is enrolled when value is for 0b1；

According to encoding information above, the continuous blocks using IC_MODE to start current block or current block carry out the volume that coding consumes Code bit number CBits^ICIt is calculated by formula (13), and current block selects IC_MODE as its effective candidate coding pattern Needing to meet two conditions, first condition is the present frame inter prediction enable mark TP written into code stream_ENValue is 0b1, the Two conditions are QDBits^ICIt is not more than 7；

5. screen video compression method as claimed in claim 1, it is characterised in that the candidate code mould in described step (5) Formula includes monodrome raw mode SO_MODE:

Using this pattern to encode, current block is not predicted and quantifies, and its all initial datas and all reconstruction data are all Equal, it is designated as monodrome P_S；

Use this pattern to encode, need further exist for enrolling following coding information code stream:

The SO_MODE coding mode mark ModeID that 2 bits represent^SO, it is worth for 0b01；

Monodrome coded system CodPsFlag that 1 bit represents^SO, its value is the upper block that 0b0 represents that current block space is adjacent Coding mode is monodrome P of SO_MODE and upper block_SMonodrome P with current block_SEqual, monodrome P of current block_SDo not enroll code Stream, decoding end obtains P from upper block_S, its value is monodrome P that 0b1 represents current block_STo enroll code stream, decoding end is directly from code stream Obtain P_S；

Monodrome P that 8 bits represent_S, this coding information is only at CodPsFlag^SOCode stream is enrolled when value is for 0b1；

The consecutive identical monodrome block identification ContiFlag that 1 bit represents^SOEnrolling code stream, its value is that 0b0 represents only current block Enrolling code stream, current block end-of-encode, its value is the continuous ContiCnt that 0b1 represents headed by current block^SOIndividual block uses SO_ MODE carries out encoding and P between each block_SEqual, following coding information also to be enrolled code stream by current block；

ContiCntBits^SOThe ContiCnt that individual bit represents^SOValue after subtracting 1, ContiCntBits^SOCalculate by formula (14) Obtaining, this coding information is only at ContiFlag^SOValue be to enroll code stream during 0b1；

The ContiCntBits that 2 bits represent^SOCode identification ContiCntBitsIdx^SO, ContiCntBitsIdx^SOWith ContiCntBits^SOCorresponding relation such as formula (15) shown in；

According to encoding information above, the continuous blocks using SO_MODE to start current block or current block carry out the volume that coding consumes Code bit number CBits^SOBeing calculated by formula (16), current block selects SO_MODE as its effective candidate coding pattern only One condition, i.e. requires that current block is monodrome block, and its all initial datas are the most equal；

CBits^SO=2+1+8 × CodPsFlag^SO+1+ContiFlag^SO×(2+ContiCntBits^SO) (16)。

6. screen video compression method as claimed in claim 1, it is characterised in that the candidate code mould in described step (5) Formula includes horizontal pointwise pattern HP_MODE:

This pattern is used to encode, to each initial data P in current block, when P is in a left side for current chroma component sub-frame Border, then the predictive value Pred of P^HPIt is 128, otherwise Pred^HPIt is all reconstruction data R of adjacent left-hand position, P space_L；The prediction of P Residual error D^HPBe calculated by formula (17), prediction residual symbol Sign^HPIt is calculated by formula (18), is quantified residual error QD^HPBy public affairs Formula (19) is calculated, rebuilds data R^HPIt is calculated by formula (20)；

D^HP=P-Pred^HP (17)

${\mathrm{Sign}}^{HP}=\left\{\begin{array}{ccc}0,& if& D^{HP}\&GreaterEqual;0\\ 1,& if& D^{HP}<0\end{array}\right.---\left(18\right)$

QD^HP=(| D^HP|+(QStep ＞ ＞ 1)) ＞ ＞ shift (19)

$R^{HP}=\left\{\begin{array}{ccc}\min ({\mathrm{Pred}}^{HP}+({\mathrm{QD}}^{HP}<<shift),255),& if& {\mathrm{Sign}}^{HP}=0\\ \max ({\mathrm{Pred}}^{HP}-({\mathrm{QD}}^{HP}<<shift),0),& if& {\mathrm{Sign}}^{HP}=1\end{array}\right.---\left(20\right)$

Use this pattern to encode, need further exist for enrolling following coding information code stream:

The coding mode mark ModeID of the HP_MODE that 3 bits represent^HP, it is worth for 0b100；

The each QD of current block that 3 bits represent^HPNumber of coded bits QDBits^HP, its value is calculated by formula (21), QD^HP _maxFor all QD of current block^HPIn maximum；

The Sign that 1 bit represents^HPAnd QDBits^HPThe QD that individual bit represents^HP, all Sign of current block^HPAnd QD^HPOnly need to be QDBits^HPCode stream is enrolled during more than 0；

According to encoding information above, use HP_MODE that current block carries out number of coded bits CBits that coding consumes^HPBy formula (22) being calculated, current block selects HP_MODE as its effective candidate coding pattern only one of which condition, i.e. QDBits^HPNo More than 7；

7. screen video compression method as claimed in claim 1, it is characterised in that the candidate code mould in described step (5) Formula includes vertical pointwise pattern VP_MODE:

This pattern is used to encode, to each initial data P in current block, when P is in the upper of current chroma component sub-frame Border, then the predictive value Pred of P^VPIt is set to 128, otherwise Pred^VPIt is all reconstruction data R of position adjacent and above, P space_U；P's is pre- Survey residual error D^VPBe calculated by formula (23), prediction residual symbol Sign^VPIt is calculated by formula (24), is quantified residual error QD^VPPress Formula (25) is calculated, rebuilds data R^VPIt is calculated by formula (26)；

D^VP=P-Pred^VP (23)

${\mathrm{Sign}}^{VP}=\left\{\begin{array}{ccc}0,& if& D^{VP}\&GreaterEqual;0\\ 1,& if& D^{VP}<0\end{array}\right.---\left(24\right)$

QD^VP=(| D^VP|+(QStep ＞ ＞ 1)) ＞ ＞ shift (25)

$R^{VP}=\left\{\begin{array}{ccc}\min ({\mathrm{Pred}}^{VP}+({\mathrm{QD}}^{VP}<<shift),255),& if& {\mathrm{Sign}}^{VP}=0\\ \max ({\mathrm{Pred}}^{VP}-({\mathrm{QD}}^{VP}<<shift),0),& if& {\mathrm{Sign}}^{VP}=1\end{array}\right.---\left(26\right)$

Use this pattern to encode, need further exist for enrolling following coding information code stream:

The coding mode mark ModeID of the VP_MODE that 3 bits represent^VP；

The each QD of current block that 3 bits represent^VPNumber of coded bits QDBits^VP, its value is calculated by formula (27), QD^VP _maxFor all QD of current block^VPIn maximum；

The Sign that 1 bit represents^VPAnd QDBits^VPThe QD that individual bit represents^VP, all Sign of current block^VPAnd QD^VPOnly need to be QDBits^VPCode stream is enrolled during more than 0；

According to encoding information above, use VP_MODE that current block carries out number of coded bits CBits that coding consumes^VPBy formula (28) being calculated, current block selects VP_MODE as its effective candidate coding pattern only one of which condition, i.e. QDBits^VPNo More than 7；

8. screen video compression method as claimed in claim 1, it is characterised in that the candidate code mould in described step (5) Formula includes level of complexity pattern CH_MODE:

Using this pattern to encode, each row of data of current block can be with selection level prediction quantification manner or direct quantification manner Encode:

In all data row using horizontal forecast quantification manner, to each initial data P, when P is in current chroma component The left margin of subframe, then the predictive value Pred of P^CHIt is set to 128, otherwise Pred^CHIt it is all the reconstruction number of adjacent left-hand position, P space According to R_L；Prediction residual D of P^CHBe calculated by formula (29), prediction residual symbol Sign^CHIt is calculated by formula (30), is quantified Residual error QD^CHIt is calculated by formula (31), is rebuild data R^CHIt is calculated by formula (32)；

In all data row using direct quantification manner, each of which initial data P, directly presses formula (33) and calculates quantization number According to QP^CH, and press reconstruction data R of formula (34) calculating P^CH；

D^CH=P-Pred^CH (29)

${\mathrm{Sign}}^{CH}=\left\{\begin{array}{ccc}0,& if& D^{CH}\&GreaterEqual;0\\ 1,& if& D^{CH}<0\end{array}\right.---\left(30\right)$

QD^CH=(| D^CH|+(QStep ＞ ＞ 1)) ＞ ＞ shift (31)

$R^{CH}=\left\{\begin{array}{ccc}\min ({\mathrm{Pred}}^{CH}+({\mathrm{QD}}^{CH}<<shift),255),& if& {\mathrm{Sign}}^{CH}=0\\ \max ({\mathrm{Pred}}^{CH}-({\mathrm{QD}}^{CH}<<shift),0),& if& {\mathrm{Sign}}^{CH}=1\end{array}\right.---\left(32\right)$

QP^CH=(P+ (QStep ＞ ＞ 1)) ＞ ＞ shift (33)

R^CH=QP^CH＜ ＜ shift (34)

Use this pattern to encode, need further exist for enrolling following coding information code stream:

The CH_MODE coding mode mark ModeID that 4 bits represent^CH, it is worth for 0b1100；

Row coded system RowMode that often 1 bit of row represents^CH, it is worth and represents that current line uses horizontal forecast quantification manner for 0b0 Encoding, its value is that 0b1 represents that current line uses direct quantification manner to encode；

The each QD of current block that 3 bits represent^CHNumber of coded bits QDBits^CH, it is calculated by formula (35), QD^CH _maxFor The all QD of current block^CHIn maximum, QDBits^CHThe data row of employing horizontal forecast quantification manner only need to be there is at current block In the case of enroll code stream；

The Sign that 1 bit represents^CHAnd QDBits^CHThe QD that individual bit represents^CH, all of Sign^CHAnd QDBits^CHOnly need QDBits^CHCode stream is enrolled in the case of more than 0；

QPBits^CHThe QP that individual bit represents^CH, wherein QPBits^CHIt is calculated by formula (36), all QP^CHOnly need to be at current block Code stream is enrolled in the case of there is the data row of the direct quantification manner of employing；

According to encoding information above, use CH_MODE that current block carries out number of coded bits CBits that coding consumes^CHBy formula (37) being calculated, in formula, n is the number of data lines that current block selects direct quantification manner；Current block selects CH_MODE as it Effectively the unique conditional of candidate coding pattern is QDBits^CHIt is not more than 7；

QPBits^CH=8-shift (36)

9. screen video compression method as claimed in claim 1, it is characterised in that the candidate code mould in described step (5) Formula includes complicated vertically pattern CV_MODE:

Using this pattern to encode, every column data of current block can select vertically to predict quantification manner or direct quantification manner Encode:

In all data row using vertically prediction quantification manner, to each initial data P, when P is in current chroma component The coboundary of subframe, then the predictive value Pred of P^CVIt is set to 128, otherwise Pred^CVIt it is all the reconstruction number of position adjacent and above, P space According to R_U；Prediction residual D of P^CVBe calculated by formula (38), prediction residual symbol Sign^CVIt is calculated by formula (39), is quantified Residual error QD^CVIt is calculated by formula (40), is rebuild data R^CVIt is calculated by formula (41)；

In all data row using direct quantification manner, each of which initial data P, directly presses formula (42) and calculates quantization number According to QP^CV, and press reconstruction data R of formula (43) calculating P^CV；

D^CV=P-Pred^CV (38)

${\mathrm{Sign}}^{CV}=\left\{\begin{array}{ccc}0,& if& D^{CV}\&GreaterEqual;0\\ 1,& if& D^{CV}<0\end{array}\right.---\left(39\right)$

QD^CV=(| D^CV|+(QStep ＞ ＞ 1)) ＞ ＞ shift (40)

$R^{CV}=\left\{\begin{array}{ccc}\min ({\mathrm{Pred}}^{CV}+({\mathrm{QD}}^{CV}<<shift),255),& if& {\mathrm{Sign}}^{CV}=0\\ \max ({\mathrm{Pred}}^{CV}-({\mathrm{QD}}^{CV}<<shift),0),& if& {\mathrm{Sign}}^{CV}=1\end{array}\right.---\left(41\right)$

QP^CV=(P+ (QStep ＞ ＞ 1)) ＞ ＞ shift (42)

R^CV=QP^CV＜ ＜ shift (43)

Use this pattern to encode, need further exist for enrolling following coding information code stream:

The CV_MODE coding mode mark ModeID that 4 bits represent^CV, it is worth for 0b1101；

Row coded system ColMode that 1 bit of each column represents^CV, it is worth and represents that quantification manner is vertically predicted in employing when prostatitis for 0b0 Encoding, its value is that 0b1 represents when prostatitis uses direct quantification manner to encode；

The each QD of current block that 3 bits represent^CVNumber of coded bits QDBits^CV, it is calculated by formula (44), QD^CV _maxFor The all QD of current block^CVIn maximum, QDBits^CVOnly need to exist at current block uses the data of vertically prediction quantification manner to arrange In the case of enroll code stream；

The Sign that 1 bit represents^CVAnd QDBits^CVThe QD that individual bit represents^CV, all of Sign^CVAnd QDBits^CVOnly need QDBits^CVCode stream is enrolled in the case of more than 0；

QPBits^CVThe QP that individual bit represents^CV, wherein QPBits^CVIt is calculated by formula (45), all QP^CVOnly need to be at current block Exist and use the data of direct quantification manner to enroll code stream in the case of arranging；

According to encoding information above, use CV_MODE that current block carries out number of coded bits CBits that coding consumes^CVBy formula (46) being calculated, in formula, m is the data columns that current block selects direct quantification manner；Current block selects CV_MODE as it Effectively the unique conditional of candidate coding pattern is QDBits^CVIt is not more than 7；

QPBits^CV=8-shift (45)

10. screen video compression method as claimed in claim 1, it is characterised in that the candidate code mould in described step (5) Formula includes self adaptation pointwise Mode A P_MODE:

This pattern is used to encode, to each initial data P in current block, its predictive value Pred^APCalculate by formula (47) Obtain, prediction residual D of P^APBe calculated by formula (48), prediction residual symbol Sign^APIt is calculated by formula (49), is measured Change residual error QD^APIt is calculated by formula (50), is rebuild data R^APIt is calculated by formula (51)；In formula (47), R_LEmpty for P Between the reconstruction data of adjacent left-hand position, R_UReconstruction data, R for position adjacent and above, P space_ULFor position, adjacent upper left, P space The reconstruction data put；

${\mathrm{Pred}}^{AP}=\left\{\begin{array}{ccc}{R}_L,& if& |R_{UL}-R_U|\&le;|R_{UL}-R_L|\\ R_U& if& |R_{UL}-R_U|>|R_{UL}-R_L|\end{array}\right.---\left(47\right)$

D^AP=P-Pred^AP (48)

${\mathrm{Sign}}^{AP}=\left\{\begin{array}{ccc}0,& if& D^{AP}\&GreaterEqual;0\\ 1,& if& D^{AP}<1\end{array}\right.---\left(49\right)$

QD^AP=(| D^AP|+(QStep ＞ ＞ 1)) ＞ ＞ shift (50)

$R^{AP}=\left\{\begin{array}{ccc}\min ({\mathrm{Pred}}^{AP}+({\mathrm{QD}}^{AP}<<shift),255),& if& {\mathrm{Sign}}^{AP}=0\\ \max ({\mathrm{Pred}}^{AP}-({\mathrm{QD}}^{AP}<<shift),0),& if& {\mathrm{Sign}}^{AP}=1\end{array}\right.---\left(51\right)$

Use this pattern to encode, need further exist for enrolling following coding information code stream:

The AP_MODE coding mode mark ModeID that 4 bits represent^AP, it is worth for 0b1110；

The each QD of current block that 3 bits represent^APNumber of coded bits QDBits^AP, its value is calculated by formula (52), QD^AP _maxFor all QD of current block^APIn maximum；

The Sign that 1 bit represents^APAnd QDBits^APThe QD that individual bit represents^AP, all Sign of current block^APAnd QD^APOnly need to be QDBits^APCode stream is enrolled during more than 0；

According to encoding information above, use AP_MODE that current block carries out number of coded bits CBits that coding consumes^APBy formula (53) being calculated, current block selects AP_MODE to have two conditions as its effective candidate coding pattern, and first condition is for working as The front piece of coboundary data not comprising current chroma component sub-frame and left margin data, second condition is QDBits^APIt is not more than 7；

11. screen video compression methods as claimed in claim 1, it is characterised in that the candidate code mould in described step (5) Formula includes direct quantitative mode DQ_MODE:

Using this pattern to encode, current block is not predicted, if the PicQ value in frame level coding information is 2 and current chroma Component sub-frame is Y-component subframe, then this pattern employing level halves quantification manner realization, and otherwise this pattern uses all sides of quantization Formula realizes；

When DQ_MODE uses whole quantification manners, to initial data P each in current block, first press formula (54) and calculate the quantization of P Data QP^DQ1, then press formula (55) calculating reconstruction data R^DQ1；

When DQ_MODE uses whole quantification manners, need further exist for enrolling following coding information code stream:

The coding mode mark ModeID of the DQ_MODE that 4 bits represent^DQ, it is worth for 0b1111；

QPBits^DQ1The QP that individual bit represents^DQ1, quantized data number of coded bits QPBits^DQ1It is calculated by formula (56)；

According to encoding information above, DQ_MODE uses whole quantification manners that current block carries out the number of coded bits that coding consumes CBits^DQ1It is calculated by formula (57)；

QP^DQ1=(P+ (QStep ＞ ＞ 1)) ＞ ＞ shift (54)

R^DQ1=QP^DQ1＜ ＜ shift (55)

QPBits^DQ1=8-shift (56)

CBits^DQ1=4+h × v × QPBits^DQ1 (57)

When DQ_MODE employing level halves quantification manner, then current block is first often taken by order from left to right in the horizontal direction Adjacent two data P_(2*i,j)And P_(2*i+1,j), calculate their average as a new data P '_(i,j), as shown in formula (58), I and j is respectively horizontal level index and the vertical position index of new data block, for being in the number of chromatic component subframe right margin According to block, if its h is odd number, often go last P_(2*i,j)There is no paired P_(2*i+1,j), then directly by P '_(i,j)It is set to P_(2*i,j)；All P ' that current block obtains after the resolution of horizontal direction halves form new data block, in new data block Each data P ', first calculates its quantized data QP by formula (59)^DQ2, then calculate its reconstruction data R ' by formula (60), finally press Formula (61) calculates the P corresponding with P '_(2*i,j)And P_(2*i+1,j)Two reconstruction data R^DQ2 _(2*i,j)And R^DQ2 _(2*i+1,j)；

P'_(i,j)=(P_(2*i,j)+P_(2*i+1,j)) ＞ ＞ 1 (58)

QP^DQ2=(P'+ (QStep ＞ ＞ 1)) ＞ ＞ shift (59)

R'=QP^DQ2＜ ＜ shift (60)

$\left\{\begin{array}{c}{R}_{(2*i,j)}^{DQ2}=R^{\&prime;}\\ R_{(2*i+1,j)}^{DQ2}=R^{\&prime;}\end{array}\right.---\left(61\right)$

When DQ_MODE employing level halves quantification manner, need further exist for enrolling following coding information code stream:

The coding mode mark ModeID of the DQ_MODE that 4 bits represent^DQ, it is worth for 0b1111；

QPBits^DQ2The QP that individual bit represents^DQ2, quantized data number of coded bits QPBits^DQ2It is calculated by formula (62)；

According to encoding information above, DQ_MODE employing level halves quantification manner and current block carries out the encoding ratio that coding consumes Special number CBits^DQ2It is calculated by formula (63)；

QPBits^DQ2=8-shift (62)

CBits^DQ2=4+ ((h+1) ＞ ＞ 1) × v × QPBits^DQ2 (63)。

The 12. such as claim 4 screen video compression methods stated to any one of claim 11, it is characterised in that described step (5) final coding mode can be chosen according to the following steps:

If (5-1) SO_MODE is effective candidate coding pattern of current block or is the consecutive identical monodrome block started from current block Effective candidate coding pattern, then directly as current block or the final coding mode of continuous blocks that starts from current block, And the data set of rebuilding under this pattern is become the final reconstructed block of correspondence position, and termination pattern selects in advance；

If (5-2) IC_MODE is effective candidate coding pattern of current block and current block exists non-zero quantised residual error, then calculates and work as Front piece uses the bit number CBits that this pattern-coding need to consume^IC；If effective candidate coding pattern that IC_MODE is current block and The quantization residual error of current block is zero, then the most also quantify residual error complete zero for IC_MODE from next BOB(beginning of block) detection subsequent block Block, until quantization residual error non-full zero block or last block being detected, and directly using IC_MODE as current block or from working as The final coding mode of the continuous blocks of front BOB(beginning of block), by under this pattern rebuild data set become correspondence position final reconstruction Block, and termination pattern selects in advance；

If (5-3) HP_MODE is effective candidate coding pattern of current block and current block exists non-zero quantised residual error, then calculates and work as Front piece uses the bit number CBits that this pattern-coding need to consume^HP；If effective candidate coding pattern that HP_MODE is current block and The quantization residual error of current block is zero, then directly as the final coding mode of current block, and by the reconstruction under this pattern The final reconstructed block of data composition current block, and terminate current block model selection in advance；

If (5-4) VP_MODE is effective candidate coding pattern of current block and current block exists non-zero quantised residual error, then calculates and work as Front piece uses the bit number CBits that this pattern-coding need to consume^VP；If effective candidate coding pattern that VP_MODE is current block and The quantization residual error of current block is zero, then directly as the final coding mode of current block, and by the reconstruction under this pattern The final reconstructed block of data composition current block, and terminate current block model selection in advance；

If (5-5) AP_MODE is effective candidate coding pattern of current block and current block exists non-zero quantised residual error, then calculates and work as Front piece uses the bit number CBits that this pattern-coding need to consume^AP；If effective candidate coding pattern that AP_MODE is current block and The quantization residual error of current block is zero, then directly as the final coding mode of current block, and by the reconstruction under this pattern The final reconstructed block of data composition current block, and terminate current block model selection in advance；

(5-6) it is unsatisfactory for becoming condition or its CBits of the effective candidate coding pattern of current block as HP_MODE^HPMore than threshold value TH1, first calculates and uses CH_MODE that current block is predicted the coding information quantified, and becomes if then CH_MODE is satisfied The condition of the effective candidate coding pattern of current block, then calculate the bit using CH_MODE that current block carries out coding needs consumption Number CBits^CH, wherein the span of TH1 is [6, h × v × QPBits^CH]；The coding staff that current block is often gone under CH_MODE Formula RowMode^CHDetermining according to formula (64), its intermediate value is that 1 expression current line uses direct quantification manner, and value is that 0 expression is current Row uses horizontal forecast quantification manner,Represent current line maximum quantization residual error QD^CH _row-maxNeed Minimum number of coded bits, threshold value TH^CHSpan be [0,7]；

(5-7) it is unsatisfactory for becoming condition or its CBits of the effective candidate coding pattern of current block as VP_MODE^VPMore than threshold value TH2, first calculates and uses CV_MODE that current block is predicted the coding information quantified, and becomes if then CV_MODE is satisfied The condition of the effective candidate coding pattern of current block, then calculate the bit using CV_MODE that current block carries out coding needs consumption Number CBits^CV, wherein the span of TH2 is [6, h × v × QPBits^CV]；Current block is the coding staff of each column under CV_MODE Formula ColMode^CVDetermining according to formula (65), its intermediate value is that 1 expression is when prostatitis uses direct quantification manner, and value is that 0 expression is current Row use and vertically predict quantification manner,Represent when prostatitis maximum quantization residual error QD^CV _col-maxNeed Minimum number of coded bits, threshold value TH^CVSpan be [0,7]；

If (5-8) DQ_MODE of current chroma component sub-frame uses whole quantification manners, then determine current block according to formula (66) Whether calculate the quantization of DQ_MODE and rebuild data, EN^DQ1Value is that 1 expression current block calculates the quantization of DQ_MODE and rebuilds number According to, value is that 0 expression current block does not calculate the quantization of DQ_MODE and rebuilds data, CBits_MINRepresent in calculated each pattern and compile Code need to consume the minima of bit number；

If the DQ_MODE use level of current chroma component sub-frame halves quantification manner, then determine that current block is by formula (67) The quantization of no calculating DQ_MODE and reconstruction data, EN^DQ2Value is that 1 expression current block calculates the quantization of DQ_MODE and rebuilds data, Value is that 0 expression current block does not calculate the quantization of DQ_MODE and rebuilds data, TotalBits_YRepresent that current Y-component subframe disappears The number of coded bits of consumption, η is coefficient of comparisons, and less than 1.0, typical value scope is [0.2,0.8]；

Current block is after formula (66) or formula (67) judge, if EN^DQ1Or EN^DQ2Value is 1, then calculate current block and use DQ_ The quantization of MODE and reconstruction data, and calculate the bit number CBits using DQ_MODE to carry out coding needs consumption^DQ, its value is CBits^DQ1Or CBits^DQ2；

${\mathrm{EN}}^{DQ1}=\left\{\begin{array}{cc}1,& \begin{array}{cc}if& {\mathrm{CBits}}_{MIN}>h\&times;v\&times;(8-shift)\end{array}\\ 0,& others\end{array}\right.---\left(66\right)$

${\mathrm{EN}}^{DQ2}=\left\{\begin{array}{cc}1,& \begin{array}{cc}if& {\mathrm{TotalBits}}_Y>\mathrm{\&eta;}\&times;H_1\&times;V_1\&times;8\end{array}\\ 0,& others\end{array}\right.---\left(67\right)$

(5-9) from the effective candidate coding pattern estimated, select finally to encode mould by the principle consuming number of coded bits minimum Formula, in the case of number of coded bits is identical, selects the coding mode ident value final coding mode of less conduct；Current block is existed Data set of rebuilding under final coding mode becomes the final reconstructed block of correspondence position.

13. screen video compression methods as claimed in claim 4, it is characterised in that described step (6) if in current block Final coding mode is interframe associative mode IC_MODE, the most as follows by coding information write code stream:

A coding mode is identified ModeID by ()^ICWrite code stream；

B stand growth model is identified AZBFlag by ()^ICWrite code stream；

If the AZBFlag of (c) write code stream^ICValue is 0b1, then jump to step (f)；

D () will quantify residual error number of bits QDBits^ICWrite code stream；

E () first presses the order of raster scanning by all of prediction residual symbol Sign^ICWrite code stream, more in the same order by institute Some quantization residual errors QD^ICWrite code stream, finally terminates the code stream write of current block；

(f) write code stream consecutive identical monodrome block identification ContiFlag^ICIf, ContiFlag^ICValue is 0b0, then terminate current block Code stream write；

G () is first by ContiCnt^ICNumber of coded bits mark ContiCntBitsIdx^ICWrite code stream, then by ContiCnt^ICSubtract 1 write code stream.

14. screen video compression methods as claimed in claim 5, it is characterised in that described step (6) if in current block Final coding mode is monodrome raw mode SO_MODE, the most as follows by coding information write code stream:

A coding mode is identified ModeID by ()^SOWrite code stream；

B () is by monodrome coded system CodPsFlag^SOWrite code stream；

If (c) CodPsFlag^SOValue is equal to 0b1, then by single-value data P_sWrite code stream；

D () is by consecutive identical monodrome block identification ContiFlag^SOWrite code stream；

If (e) ContiFlag^SOValue is equal to 0b1, the most first by ContiCnt^SONumber of coded bits mark ContiCntBitsIdx^SO Write code stream, then by ContiCnt^SOThe write code stream that subtracts 1.

15. screen video compression methods as claimed in claim 6, it is characterised in that described step (6) if in current block Final coding mode is horizontal pointwise pattern HP_MODE, the most as follows by coding information write code stream:

A coding mode is identified ModeID by ()^HPWrite code stream；

B () will quantify residual error number of bits QDBits^HPWrite code stream；

If (c) QDBits^HPValue, more than 0, the most first presses the order of raster scanning by all of for current block prediction residual symbol Sign^HPWrite Enter code stream, more in the same order by all of for current block quantization residual error QD^HPWrite code stream.

16. screen video compression methods as claimed in claim 7, it is characterised in that described step (6) if in current block Final coding mode is vertical pointwise pattern VP_MODE, the most as follows by the coding information write code stream of current block:

A coding mode is identified ModeID by ()^VPWrite code stream；

B () will quantify residual error number of bits QDBits^VPWrite code stream；

If (c) QDBits^VPValue, more than 0, the most first presses the order of raster scanning by all of prediction residual symbol Sign^VPWrite code Stream, more in the same order by all of quantization residual error QD^VPWrite code stream.

17. screen video compression methods as claimed in claim 8, it is characterised in that described step (6) if in current block Final coding mode is level of complexity pattern CH_MODE, the most as follows by the coding information write code stream of current block:

A coding mode is identified ModeID by ()^CHWrite code stream；

B () presses order from top to bottom by coded system RowMode of each row of data^CHWrite code stream；

(c) point following three kinds of situations write code stream:

(c-1) if the RowMode of all write code streams^CHValue is all 0b1, then press the order of raster scanning by all of for current block amount Change data QP^CHWrite code stream；

(c-2) if writing the RowMode of code stream^CHValue is all 0b0, first will quantify residual error number of bits QDBits^CHWrite code Stream；If then QDBits^CHMore than 0, the most first press the order of raster scanning by all of for current block prediction residual symbol Sign^CHWrite Enter code stream, more in the same order by all of for current block quantization residual error QD^CHWrite code stream；

(c-3) if writing the RowMode of code stream^CHValue for 0b0 and all exists for 0b1, first will quantify residual error number of bits QDBits^CHWrite code stream；If then QDBits^CHMore than 0, the most first press the order of raster scanning by residual for all of for current block prediction Difference symbol Sign^CHWrite code stream, more in the same order by all of for current block quantization residual error QD^CHWrite code stream；Finally press light The order of grid scanning is by all of for current block quantized data QP^CHWrite code stream.

18. screen video compression methods as claimed in claim 9, it is characterised in that described step (6) if in current block Final coding mode be complicated vertically pattern CV_MODE, and the information that encoded the most as follows writes code stream:

A coding mode is identified ModeID by ()^CVWrite code stream；

B () presses order from left to right by each column coded system ColMode^CVWrite code stream；

(c) point following three kinds of situations write code stream:

(c-1) if the ColMode of all write code streams^CVValue is all 0b1, then press the order of raster scanning by all of quantized data QP^CVWrite code stream；

(c-2) if the ColMode of all write code streams^CVValue is all 0b0, first will quantify residual error number of bits QDBits^CVWrite Enter code stream；If then QDBits^CVMore than 0, the most first press the order of raster scanning by all of for current block prediction residual symbol Sign^CVWrite code stream, more in the same order by all of for current block quantization residual error QD^CVWrite code stream；

(c-3) if writing the ColMode of code stream^CVValue for 0b0 and all exists for 0b1, first will quantify residual error number of bits QDBits^CVWrite code stream；If then QDBits^CVMore than 0, the most first press the order of raster scanning by residual for all of for current block prediction Difference symbol Sign^CVWrite code stream, more in the same order by all of for current block quantization residual error QD^CVWrite code stream；Finally press light The order of grid scanning is by all of for current block quantized data QP^CVWrite code stream.

19. screen video compression methods as claimed in claim 10, it is characterised in that described step (6) if in current block Final coding mode be self adaptation pointwise Mode A P_MODE, encoded the most as follows information write code stream:

A coding mode is identified ModeID by ()^APWrite code stream；

B () will quantify residual error number of bits QDBits^APWrite code stream；

If (c) QDBits^APValue, more than 0, the most first presses the order of raster scanning by all of prediction residual symbol Sign^APWrite code Stream, more in the same order by all of quantization residual error QD^APWrite code stream.

20. screen video compression methods as claimed in claim 11, it is characterised in that described step (6) if in current block Final coding mode be direct quantitative mode DQ_MODE, encoded the most as follows information write code stream:

A coding mode is identified ModeID by ()^DQWrite code stream；

If b () DQ_MODE uses the implementation all quantified, then press the order of raster scanning by all quantized data QP^DQ1Write Enter code stream；If DQ_MODE employing level halves the implementation of quantization, then press the order of raster scanning by all quantized datas QP^DQ2Write code stream.

21. screen video compression methods as claimed in claim 1, it is characterised in that described step (10) is to present frame code Stream carries out frame sync identifications escape process, and concrete grammar is as follows:

To each byte after the frame sync identifications of present frame code stream, read the data of this byte and 3 bytes thereafter in order, Form 4 byte datas FourBytes, the most first read byte and be placed on higher bit position；When FourBytes value is 0xFFFFFFFD, then In code stream, after 0xFD, insert a byte data, be worth for 0x00, when FourBytes value is 0xFFFFFFFE, then by code stream In 0xFE replace with 0xFD, and after 0xFD, insert a byte data, be worth for 0x01；Decoding end is entered at present frame code stream First continuous five byte values all in present frame code stream must be last in 0xFFFFFFFD00 before resolving and rebuilding by row Byte 0x00 is deleted, and is that in 0xFFFFFFFD01, the 4th byte 0xFD replaces with 0xFE by all continuous five byte values, and will Last byte 0x01 is deleted.