CN103037213B - The cloth woods entropy decoding method of cloth woods entropy decoder and image playing system - Google Patents

Abstract

The invention provides the cloth woods entropy decoding method of a kind of cloth woods entropy decoder and image playing system.Wherein cloth woods entropy decoder comprises decoder module, buffer and update module.Decoder module sequentially produces the first cloth woods value, the second cloth woods value and the 3rd cloth woods value according to a bit element flow.First and second cloth woods value produces in the same work period.Decoder module needs the first bit amount when producing the numerical value corresponding to the first cloth woods value, in time producing the numerical value corresponding to the second cloth woods value, need second bit amount.Buffer in order to the bit segment in this bit element flow temporary, for this decoder module.Update module upgrades buffer according to the first bit amount and second bit amount after bit element flow acquisition one new bit segment.Decoder module optionally adjusts the numerical value corresponding to the 3rd cloth woods value after buffer is updated.

Description

The cloth woods entropy decoding method of cloth woods entropy decoder and image playing system

Technical field

The present invention is relevant to image processing technique, and especially relevant with the technology promoting image processing efficiency to shortening decode time.

Background technology

One of the development trend of multimedia play system is the size continuing to increase video display now.Accordingly, the arithmetic speed of image processor also must promote thereupon.To adopt the display of hd-tv system (high-definitiontelevision, HDTV) standard, the arithmetic speed of its decoding device must reach at least be enough to process 60 resolutions per second be the picture of 1920*1080.Accordingly, the work period how shortening decoding device is the subject under discussion more and more come into one's own to increase decoding efficiency.

Cloth woods entropy decoder (booleanentropydecoder) is a kind of decoder be widely used in image processing system, and its function is the cloth woods value be converted to by bit element flow (bitstream) corresponding to image data.Fig. 1 is typical cloth woods entropy decoder block diagram.In this framework, decoder 100 sequentially produces two cloth woods values in each work period T.At generation cloth woods value B ₀time, first must calculate according to following equation and correspond to cloth woods value B ₀a separation number (split) S ₀:

$S_0=1+\frac{(R_0-1)*P_0}{256},$ (formula one)

Wherein, corresponding to cloth woods value B ₀a scope R ₀and a numerical value V ₀relevant to previous cloth woods value, can learn in advance; Probability P ₀can by generation of tabling look-up.Electrical combination 12A is responsible for the computing in execution formula one, to produce separation number S ₀.In practice, scope R ₀, separation number S ₀with numerical value V ₀be all integer, available binary bit eight bit represents.The numerical value V of first cloth woods value of whole picture ₀usually eight bits foremost into bit element flow are preset in.

Comparator 12B is in order to compare separation number S ₀with numerical value V ₀, to determine cloth woods value B ₀be 1 or 0.If separation number S ₀be less than or equal to numerical value V ₀, cloth woods value B ₀equal 1.Relatively, if separation number S ₀be greater than numerical value V ₀, cloth woods value B ₀equal 0.

Corresponding to next cloth woods value B ₁scope R ₁with numerical value V ₁with cloth woods value B ₀relevant, and can at decision cloth woods value B ₀produce through (renormalization) program of reforming afterwards.Ruo Bulin value B ₀be 1, R ₁initial value R _{1 (0)}to be R ₀deduct S ₀, V ₁initial value V _{1 (0)}to be V ₀deduct S ₀.Ruo Bulin value B ₀be 0, R ₁initial value R _{1 (0)}s will be equaled ₀, V ₁initial value V _{1 (0)}equal V ₀.As shown in Figure 1, subtracter 12C is responsible for generation scope R ₀and separation number S ₀difference.Bu Lin value B ₀be provided to multiplexer 12D, in order to control the initial value R of reformer unit 12E will be provided to _{1 (0)}separation number S ₀or scope R ₀and separation number S ₀difference.Similarly, cloth woods value B ₀also multiplexer 12F is provided to, in order to control the initial value V of reformer unit 12E will be provided to _{1 (0)}numerical value V ₀or numerical value V ₀with separation number S ₀difference.

Subsequently, reformer unit 12E is responsible for selectivity and adjusts and determine scope R ₁with numerical value V ₁, its adjustment mode can be expressed as follows:

while(R ₁＜128){

R ₁＝R ₁*2；

V ₁＝[(V ₁*2)+nbit(1)]}。(formula two)

That is, if current R ₁be less than 128, R ₁can 2 be multiplied by, until R ₁be more than or equal to 128.Improving R at every turn ₁process in, V ₁also can be multiplied by 2 accordingly, be added in bit element flow not yet by first bit of part used.With R ₁be example being multiplied by the situation being just greater than 128 after 2 three times, reformer unit 12E to capture in bit element flow not yet by first three bit of using for producing numerical value V ₁use.As shown in Figure 1, numerical value of N ₁represent reformer unit 12E at generation numerical value V ₁process in need from not yet by the bit amount captured in the bit element flow that uses.Numerical value of N ₂then represent reformer unit 14E at generation numerical value V ₂process in need from not yet by the bit amount captured in the bit element flow that uses.Buffer 18 in Fig. 1 namely in order in temporary bit element flow not yet by the partial sector used, produce numerical value V for reformer unit 12E/14E ₁in time, uses.That is, numerical value V is produced respectively in reformer unit 12E and reformer unit 14E ₁and numerical value V ₂time, required specific bit must being had in buffer 18, being operated in order to do making reformer unit 12E and reformer unit 14E.

Confirming scope R ₁with numerical value V ₁afterwards, combinational circuit 14A can according to scope R ₁, probability P ₁(can by generation of tabling look-up) and formula one calculate separation number S ₁.By comparing separation number S ₁with the numerical value V produced by reformer unit 12E ₁, comparator 14B can determine cloth woods value B ₁be 1 or 0.

Similarly, corresponding to next cloth woods value B ₂scope R ₂with numerical value V ₂with cloth woods value B ₁relevant, and can at decision cloth woods value B ₁produce through reorganization procedure afterwards.As shown in Figure 1, subtracter 14C is responsible for generation scope R ₁and separation number S ₁difference.Bu Lin value B ₁be provided to multiplexer 14D, in order to control the R that reformer unit 14E will be provided to ₂initial value R _{2 (0)}separation number S ₁or scope R ₁and separation number S ₁difference.Bu Lin value B ₁also multiplexer 14F is provided to, in order to control the V that reformer unit 14E will be provided to ₂initial value V _{2 (0)}numerical value V ₁or numerical value V ₁with separation number S ₁difference.Subsequently, reformer unit 14E is responsible for determining next cloth woods value B ₂scope R ₂with numerical value V ₂.

In practice, circuit 12A ~ 12E can be utilized to produce cloth woods value B again ₂, and circuit 14A ~ 14E can in order to produce follow-up cloth woods value B ₃, circulate according to this, progressively produce a series of cloth woods value.

As shown in Figure 1, updating block 16 receives the numerical value of N that reformer unit 12E provides respectively ₁with the numerical value of N that reformer unit 14E provides ₂.Numerical value of N ₁represent reformer unit 12E at generation numerical value V ₁process in need from not yet by the bit amount captured in the bit element flow that uses.Numerical value of N ₂then represent reformer unit 14E at generation numerical value V ₂process in need from not yet by the bit amount captured in the bit element flow that uses.According to numerical value of N ₁and numerical value of N ₂, updating block 16 calculates the several bits altogether employed in this work period T in bit element flow, and upgrades the content of buffer 18 accordingly.

Fig. 2 is the content example of buffer 18.Suppose the capacity of buffer 18 be 16 bits and have in first cycle T 1 bit [20:35] in bit element flow (label be 20 bit start to label be the bit of 35).If numerical value of N ₁and numerical value of N ₂summation be 8, front 8 bits [20:27] representing in bit [20:35] have been reformed unit 12E/14E and have used in work period T1.Therefore, updating block 16 captures 8 bits [36:43] follow-up in this bit element flow by memory (not being illustrated in the figure) request storing this bit element flow, and make the content of buffer 18 be updated to bit [28:43] before the second work period T2 starts, that is leave out front end by eight bits used, its content is updated to and has the state that 16 do not use bit, in the second work period T2, produce numerical value V for reformer unit 12E/14E ₃, V ₄in time, uses.In like manner, updating block 16 is next time according to generation numerical value V ₃, V ₄time use number of cells (numerical value of N ₃and numerical value of N ₄summation) before the work period, T3 started, upgrade buffer 18.

In each reforming process, when producing a numerical value V, 7 bits can be taken at the most in bit element flow.The capacity of buffer 18 is usually designed in enough single cycles for producing the numerical value V corresponding to two cloth woods values.As shown in Figure 2, cloth woods entropy decoder 100 can produce two cloth woods values in each work period, and the content of buffer 18 can change along with the number of cells difference consumed in each cycle or remain unchanged.

With regard to the framework of Fig. 1, numerical value of N ₁generation inevitable early than numerical value of N ₂, but updating block 16 must wait for that reformer unit 14E produces numerical value of N ₂after could determine should capture how many bit amount to upgrade the content of buffer 18.For Fig. 2, reformer unit 14E is at time point t _a1produce numerical value of N ₂, from time point t _a1time before work period T1 terminates is then for updating block 16 bit required when bit element flow captures follow-up renewal buffer 18.Wait until that the content update of buffer 18 is complete, next work period T2 could start.Can find out thus, the time of acquisition data and renewal buffer can make each work period T of cloth woods entropy decoder 100 increase, thus cause its operating frequency to reduce, cloth woods entropy decoder 100 even may be caused cannot to reach the result of the requirement of some high-resolution image system.

Summary of the invention

For the problems referred to above, the present invention proposes a kind of new cloth woods entropy decoder framework, and the time point by change acquisition data shortens the work period each time.In addition, utilize many group circuit to calculate multiple possible outcome, the time required for decoding can be shortened further simultaneously.

A specific embodiment according to the present invention is a cloth woods entropy decoder, in order to a bit element flow to be converted to multiple cloth woods value.This decoder comprises a decoder module, a buffer and a update module.This decoder module sequentially produces one first cloth woods value, one second cloth woods value and one the 3rd cloth woods value according to this bit element flow.This first cloth woods value and this second cloth woods value produce in the same work period.This decoder module needs one first bit amount when producing the numerical value corresponding to this first cloth woods value, and needs a second bit amount in time producing the numerical value corresponding to this second cloth woods value.This buffer in order to the bit segment in this bit element flow temporary, for this decoder module.This bit segment at least contains this first bit amount and this second bit amount.This update module upgrades this buffer according to this first bit amount and this second bit amount after this bit element flow acquisition one new bit segment.This decoder module optionally adjusts the numerical value corresponding to the 3rd cloth woods value after this buffer is updated.

Another specific embodiment according to the present invention is a kind of cloth woods entropy decoding method being applied to image playing system, in order to a bit element flow to be converted to the multiple cloth woods values corresponding to image data.This image playing system comprises a buffer, in order to the bit segment in this bit element flow temporary.First, utilize in this bit segment one first section with one first bit amount, the numerical value corresponding to one first cloth woods value is produced.Then, in one first work period, the first cloth woods value is produced.Subsequently, utilize in this bit segment one second section with a second bit amount, the numerical value corresponding to one second cloth woods value is produced.Captured from this bit element flow according to this first bit amount and the new bit segment of this second bit amount one, and this buffer is updated according to this new bit segment.Same in this first work period, this second cloth woods value and the numerical value corresponding to one the 3rd cloth woods value are produced.After this buffer is updated, this numerical value corresponding to the 3rd cloth woods value is optionally adjusted.Then, in one second work period, the 3rd cloth woods value is produced.

Can be further understood by following detailed Description Of The Invention and institute's accompanying drawing about the advantages and spirit of the present invention.

Accompanying drawing explanation

Fig. 1 is typical cloth woods entropy decoder block diagram.

Fig. 2 is the buffer content example in traditional cloth woods entropy decoder.

Fig. 3 is the circuit block diagram according to cloth woods entropy decoder in a specific embodiment of the present invention.

Fig. 4 and Fig. 5 is according to the buffer content example in cloth woods entropy decoder of the present invention.

Fig. 6, Fig. 7, Fig. 8, Fig. 9 are respectively the local circuit calcspar example according to decoder module of the present invention.

Figure 10 is the flow chart according to cloth woods entropy decoding method in a specific embodiment of the present invention.

Main element symbol description

100: cloth woods entropy decoder 12A, 14A: electrical combination

12B, 14B: comparator 12C, 14C: subtracter

12D, 14D: multiplexer 12E, 14E: reformer unit

12F, 14F: multiplexer 16: updating block

18: buffer 18200: cloth woods entropy decoder

20: decoder module 26: update module

28: buffer 60: electrical combination

61A: multiplier 61B: divider

62: judging unit 63: the first adjustment unit

64: the second adjustment unit 65A ~ 65H: electrical combination

66: multiplexer 67A ~ 67C, 68A ~ 68B: multiplexer

69: reformer unit 70: the three adjustment unit

S11 ~ S18: process step

Embodiment

A specific embodiment according to the present invention is a cloth woods entropy decoder, in order to a bit element flow to be converted to multiple cloth woods value; Fig. 3 is its circuit block diagram.Cloth woods entropy decoder 200 comprises decoder module 20, update module 26 and buffer 28.In practical application, cloth woods entropy decoder 200 can be incorporated in the multimedia system of various employing cloth woods entropy code, the such as image processing system of VP8 specification.

In practice, decoder module 20 is designed to comprise the circuit 12A ~ 12E in figure mono-and circuit 14A ~ 14E, but not as limit.According to the bit element flow inputing to cloth woods entropy decoder 200, decoder module 20 sequentially produces one first cloth woods value B ₁, one second cloth woods value B ₂and one the 3rd cloth woods value B ₃.Should be noted that, in this embodiment, the first cloth woods value B ₁with the second cloth woods value B ₂produce in the same work period, and the 3rd cloth woods value B ₃produce in a rear work period.With the cloth woods value B shown in Fig. 4 ₁~ B ₃for example, the first cloth woods value B ₁can be produced by circuit 12A ~ 12E at the leading portion of period 1 T1, the second cloth woods value B ₂can be produced by circuit 14A ~ 14E at the back segment of period 1 T1, and the 3rd cloth woods value B ₃can be second round T2 leading portion produced by circuit 12A ~ 12E, the rest may be inferred.

Decoder module 20 produces and corresponds to the first cloth woods value B ₁numerical value V ₁time need one first bit amount N ₁, produce and correspond to the second cloth woods value B ₂numerical value V ₂time need a second bit amount N ₂.First bit amount N ₁represent and produce numerical value V in reformation (renormalization) program ₁time, altogether need to capture in bit element flow, not yet by the bit amount used, second bit amount N ₂representative produces numerical value V in reorganization procedure ₂time, altogether need to capture in bit element flow, not yet by the bit amount used.Buffer 28, in order to the bit segment in temporary bit element flow, is taken when producing these numerical value V for decoder module 20.With the cloth woods value B shown in Fig. 4 ₁~ B ₃for example, the first bit amount N ₁in work period T0, produce cloth woods value B ₀after reorganization procedure determine, namely decoder module 20 takes required specific N in time point t1 in buffer 28 ₁individual bit; And second bit amount N ₂in work period T1, produce cloth woods value B ₁after reorganization procedure determine, namely decoder module 20 takes required specific N in time point t2 in buffer 28 ₂individual bit.

In work period T1, second bit amount N is determined at decoder module 20 ₂after, the update module 26 in this embodiment is according to second bit amount N ₂and the first bit amount N produced in previous work period T0 ₁from bit element flow acquisition one new bit segment.Be different from prior art, update module 26 is not pursuant to two bit amounts (the bit amount N determined in the work period T1 that such as coexists determined in the same work period ₂, N ₃) calculating subsequently will from the bit amount of bit element flow acquisition, and adopt across two work periods, the bit amount that the bit amount of the back segment decision of last work period and the leading portion of a rear work period determine, calculating subsequently will from the bit amount of bit element flow acquisition.For the situation that Fig. 4 illustrates, the first bit amount N ₁the time point produced is t1, second bit amount N ₂the time point produced is t2.Bit amount N is confirmed at time point t2 ₂after, the update module 26 in this embodiment is namely according to N ₁and N ₂summation determine next how to upgrade the content of buffer 28.

On the other hand, as shown in Figure 4, the time that the buffer 28 in this embodiment is updated remains at the end of each work period (such as at the 3rd bit amount N ₃the time point t3 produced).By making update module 26 by required for acquisition bit and the step timesharing execution upgrading buffer, and the bit captured between time point t2 and t3 needed for follow-up renewal buffer 28 ahead of time, update module 26 only needs the content upgrading buffer 28 after time point t3, and saves the time of the required bit of acquisition; Accordingly, the work period of cloth woods entropy decoder 200 can be shortened, and is equal to and improves its operating frequency.

For Fig. 4, hypothesis decoding module 20 judges the first bit amount N at time point t1 ₁equal 5, judge second bit amount N at time point t2 ₂equal 0.Update module 26 can according to N ₁and N ₂summation learn, in the middle of the bit [28:43] that current buffer 28 stores, the first five bit (namely bit [28:32]) decoded module 20 uses.Therefore, update module 26 in time point t2 start to bit of storage flow filament memory (not being illustrated in figure) request acquisition bit element flow in follow-up five not yet by the bit (bit [44:48]) used.In practice, the time of this section of acquisition data can be shorter than the interval of time point t2 and t3, and therefore update module 26 can complete the program of data acquisition before time point t3.At time point t3, new bit segment is loaded into buffer 28 by update module 26, makes the content of buffer 28 be updated to bit [33:48].In another embodiment, update module 26 also can upgrade the content of buffer 28 immediately after completing acquisition data program, not necessarily will wait until that time point t3 just starts to upgrade buffer 28.

Fig. 5 is another example of buffer 28 content.First see work period T0, suppose at time point t _a1twice reorganization procedure before employs [20:27] eight bits in buffer 28 altogether, and update module 26 is at time point t _a1can ask, from follow-up eight bits [36:43] of bit element flow acquisition, by this when next update buffer 28, to make its stored contents be updated to bit [28:43].As figure 55 shows, update module 26 is at cloth woods value B ₀when reorganization procedure after generation completes, (namely at the end of work period T0) upgrades the content of buffer 28.As discussed previously, the reorganization procedure carried out at work period T0 back segment can determine to correspond to the first cloth woods value B ₁numerical value V ₁.In this example, produce numerical value V ₁time need use the data (bit [28:34]) of seven bits in bit element flow, therefore the first bit amount N ₁equal 7.

At time point t _a2, decoder module 20 completes at cloth woods value B ₁reorganization procedure after generation.In this example, produce numerical value V ₂time also need the data (bit [35:41]) using seven bits in bit element flow, therefore second bit amount N ₂equal 7.Update module 26 is learnt immediately and is produced numerical value V ₁, V ₂altogether need [28:41] 14 bits, therefore can at time point t _a2rear now requests from follow-up 14 bits (bit [44:57]) being not yet written into buffer 28 of bit element flow acquisition, and upgrades buffer 28 at the end of work period T1, makes its stored contents can be updated to bit [42:57].

As shown in Figure 5, numerical value V is produced ₃time also need the data (bit [42:48]) using seven bits in bit element flow.Should be noted that, although the work period T1 content that interior buffer 28 stores during this period of time is not enough to supply produce numerical value V ₃reorganization procedure needed for, but decoder module 20 can to wait until that the content of buffer 28 is updated to bit [42:57] (can be even) just upgrade numerical value V according to the content (bit [42:57]) of now buffer 28 afterwards after the work period, T2 started ₃.More particularly, decoder module 20 first can calculate R at the reorganization procedure of work period T1 back segment _{3 (0)}be just be greater than 128 after being multiplied by 2 seven times, learn the 3rd bit amount N accordingly ₃equal 7.Accordingly, in above-mentioned reorganization procedure, V _{3 (0)}also 2 seven times can be multiplied by, to draw V to be updated ₃.After the content of buffer 28 is updated to bit [42:57], decoder module 20 obtains bit [42:48] immediately in buffer 28, and by bit [42:48] and V previously to be updated ₃be added, make numerical value V ₃be updated to correct result, for generation cloth woods value B ₃use.

Should be noted that, if the work period T1 content that interior buffer 28 stores during this period of time has been enough to supply produce numerical value V ₃needed for, namely decoder module 20 need not adjust numerical value V after buffer 28 upgrades ₃.In sum, decoder module 20 optionally adjusts and corresponds to the 3rd cloth woods value B after buffer 28 is updated ₃numerical value V ₃.Can be found out by above example, the work period T1 content that interior buffer 28 stores during this period of time is actually for cloth woods value B ₀, B ₁reorganization procedure after generation uses.In like manner, the work period T2 content that interior buffer 28 stores during this period of time is for cloth woods value B ₂, B ₃reorganization procedure after generation uses.Therefore, as long as the bit segment during work period T1 stored by buffer 28 at least contains the first bit amount N ₁and second bit amount N ₂.For example, if the first bit amount N ₁and second bit amount N ₂be at most 7 bits separately, the first bit amount N ₁and second bit amount N ₂addition is at most 14 bits, then a buffer 28 with 16 bit capacity is sufficient.

Below will to produce cloth woods value B in same work period T ₀, B ₁situation be example, another execution mode of decoder module 20 is described.As discussed previously, cloth woods value B ₀may be 1 or 0, and produce cloth woods value B ₀the issuable result of reorganization procedure is afterwards eight kinds at the most and (corresponds respectively to N ₁=0 ~ 7).Therefore, cloth woods value B ₀the result ([R of the reorganization procedure after generation ₁, V ₁]) have 16 kinds of possibilities.To give a definition as cloth woods value B ₀probability P when being 0 ₁for P _l, as cloth woods value B ₀probability P when being 1 ₁for P _m.

First cloth woods value B is discussed ₀be 0 and N ₁the situation of=0.Such situation represents, R ₁initial value R _{1 (0)}equal S ₀and be more than or equal to 128, therefore:

$S_0=1+\frac{(R_0-1)*P_0}{256}\≥128.$ (formula one A)

Can be drawn by formula one A: $\frac{(R_0-1)*P_0}{256}>126.$ (formula one B)

If with numerical value S ₀_ m1 represents separation number after an adjustment then formula one B can be rewritten as:

S ₀_m1＞126。(formula one C)

That is, Ruo Bulin value B ₀be 0 and N ₁=0, then formula one C sets up.In other words, Yu Bulin value B ₀when, formula one C is with S ₀the magnitude range of _ m1 judges N ₁the judgement formula of value.

In addition, V ₁initial value V _{1 (0)}equal V ₀, and reorganization procedure need not adjust R _{1 (0)}and V _{1 (0)}.Easy speech it, R ₁equal R _{1 (0)}equal S ₀, V ₁equal V _{1 (0)}equal V ₀.Therefore, then at relatively V ₁and S ₁to determine cloth woods value B ₁when being 1 or 0, compare V ₀whether be more than or equal to be equal to and compare V ₀whether be greater than in sum, cloth woods value B is determined ₁comparison expression when being 1 or 0 can be expressed as follows:

$V_0>?\frac{(S_0-1)*P_1}{256}=\frac{\frac{(R_0-1)*P_0}{256}*P_L}{256}.$ (formula one D)

If with numerical value S ₀_ m1 represents then formula one D can be rewritten as:

$V_0>?\frac{S_0\_m1*P_L}{256}.$ (formula one E)

From above-mentioned formula one C and formula one E, by this numerical value of definition S ₀_ m1, the present embodiment can simplify judgement N simultaneously ₁value and decision cloth woods value B ₁judgement formula, make the hardware that the present embodiment can be less produce cloth woods value B ₁and the judgement of relevant parameter.Following situation is also spiritual according to this simplifies judgement N ₁value and decision cloth woods value B ₁judgement formula, hereby details are as follows.Cloth woods value B is then discussed ₀be 0 and N ₁the situation of=1.Such situation represents, R ₁initial value R _{1 (0)}equal S ₀and be less than 128 and be more than or equal to 64, therefore:

$128>S_0=1+\frac{(R_0-1)*P_0}{256}\≥64.$ (formula two A)

Can be drawn by formula two A: 126>=S ₀_ m1 > 62.(formula two B)

That is, Ruo Bulin value B ₀be 0 and N ₁=1, then formula two B sets up.

In addition, V ₁initial value V _{1 (0)}equal V ₀, and reorganization procedure must adjustment R _{1 (0)}and V _{1 (0)}.Easy speech it, R ₁equal R _{1 (0)}be multiplied by 2, also equal S ₀be multiplied by 2; V ₁equal V _{1 (0)}be multiplied by and add in bit element flow not yet by 1 bit used after 2, also equal V ₀be multiplied by after 2 and add in bit element flow not yet by 1 bit used.Therefore, then at relatively V ₁and S ₁to determine cloth woods value B ₁when being 1 or 0, judge whether following relationship is set up:

$\{V_0,\mathrm{nbit}\left(1\right)\}\≥1+\frac{(R_1-1)*P_L}{256},$ (formula two C)

Wherein { V ₀, nbit (1) } represent V ₀carry out once such as formula the adjustment (adding an original bit after being multiplied by 2) described in two.

Formula two C is equal to:

$\{V_0,\mathrm{nbit}\left(1\right)\}>\frac{(2S_0-1)*P_L}{256}.$ (formula two D)

In sum, cloth woods value B is determined ₁be 1 or 0 comparison expression can be expressed as follows:

$\{V_0,\mathrm{nbit}\left(1\right)\}>?\frac{[\frac{(R_0-1)*P_0}{256}*2+1]*P_L}{256}.$ (formula two E)

Formula two E can be rewritten as again:

$\{V_0,\mathrm{nbit}\left(1\right)\}>?\frac{[S_0\_m1*2+1]*P_L}{256}.$ (formula two F)

The rest may be inferred, Ruo Bulin value B ₀be 0 and N ₁=2, following equation is set up:

62>=S ₀_ m1 > 30, (formula three A)

And determine cloth woods value B ₁comparison expression when being 1 or 0 can be expressed as:

$\{V_0,\mathrm{nbit}\left(2\right)\}>?\frac{[S_0\_m1*4+3]*P_L}{256},$ (formula three B).

Wherein { V ₀, nbit (2) } represent V ₀carry out twice such as formula the adjustment described in two.

Ruo Bulin value B ₀be 0 and N ₁=3, following equation is set up:

30>=S ₀_ m1 > 14, (formula four A)

And determine cloth woods value B ₁comparison expression when being 1 or 0 can be expressed as:

$\{V_0,\mathrm{nbit}\left(3\right)\}>?\frac{[S_0\_m1*8+7]*P_L}{256}.$ (formula four B).

Ruo Bulin value B ₀be 0 and N ₁=4, following equation is set up:

14>=S ₀_ m1 > 6, (formula five A)

And determine cloth woods value B ₁comparison expression when being 1 or 0 can be expressed as:

$\{V_0,\mathrm{nbit}\left(4\right)\}>?\frac{[S_0\_m1*16+15]*P_L}{256}.$ (formula five B).

Ruo Bulin value B ₀be 0 and N ₁=5, following equation is set up:

6>=S ₀_ m1 > 2, (formula six A)

And determine cloth woods value B ₁comparison expression when being 1 or 0 can be expressed as:

$\{V_0,\mathrm{nbit}\left(5\right)\}>?\frac{[S_0\_m1*32+31]*P_L}{256}.$ (formula six B).

Ruo Bulin value B ₀be 0 and N ₁=6, following equation is set up:

2>=S ₀_ m1 > 0, (formula seven A)

And determine cloth woods value B ₁comparison expression when being 1 or 0 can be expressed as:

$\{V_0,\mathrm{nbit}\left(6\right)\}>?\frac{[S_0\_m1*64+63]*P_L}{256}.$ (formula seven B).

Ruo Bulin value B ₀be 0 and N ₁=7, following equation is set up:

S ₀_ m1=0, (formula eight A)

And determine cloth woods value B ₁comparison expression when being 1 or 0 can be expressed as:

$\{V_0,\mathrm{nbit}\left(7\right)\}>?\frac{[S_0\_m1*128+127]*P_L}{256}.$ (formula eight B).

In sum, according to numerical value S ₀_ m1 drops within which scope that the seven number strokes such as 0,2,6,14,30,62,126 divide, can judge N ₁be which numerical value in 0 ~ 7.Fig. 6 illustrates the circuit example realizing above-mentioned each group of judgement formula.First, multiplier 61A and divider 61B is responsible for preliminary computing, produces S ₀_ m1.Judging unit 62 is responsible for according to numerical value S ₀_ m1 judges N ₁be which numerical value in 0 ~ 7.

On the other hand, by the first adjustment unit 63, second adjustment unit 64 and electrical combination 65A ~ 65H according to above-mentioned decision cloth woods value B ₁each group of judgement formula, respectively produce eight correspond to different N ₁the cloth woods value B of value ₁, and by the responsible N exported according to judging unit 62 of multiplexer 66 ₁, in the output by electrical combination 65A ~ 65H, select correct cloth woods value B ₁.The S of the first adjustment unit 63 in order to export according to divider 61B ₀_ m1 calculates S ₀_ m1*2+1, S ₀_ m1*4+3, S ₀_ m1*8+7, S ₀_ m1*16+15, S ₀_ m1*32+31, S ₀_ m1*64+63, S ₀seven terms of reference such as _ m1*128+127 are how many respectively.Second adjustment unit 64 is responsible for according to V ₀calculate { V ₀, nbit (1) }, { V ₀, nbit (2) }, { V ₀, nbit (3) }, { V ₀, nbit (4) }, { V ₀, nbit (5) }, { V ₀, nbit (6) }, { V ₀, nbit (7) } etc. seven referential datas be how many respectively.In practice, the first adjustment unit 63 only needs S ₀_ m1 moves to left and fills 1 at most low order bit and can produce above-mentioned seven terms of reference, need not the extra hardware such as adder and multiplier.

Electrical combination 65A receives V ₀and the S that divider 61B exports ₀_ m1, and perform the computing represented by formula one E, to produce cloth woods value B ₀be 0 and N ₁cloth woods value B corresponding when=0 ₁.Electrical combination 65B receives the S that the first adjustment unit 63 exports ₀{ the V that _ m1*2+1 and the second adjustment unit 64 export ₀, nbit (1) }, and perform the computing represented by formula two F, produce cloth woods value B ₀be 0 and N ₁cloth woods value B corresponding when=1 ₁.As shown in Figure 6, electrical combination 65C ~ 65H produces the cloth woods value B corresponding to other six kinds of situations respectively ₁.Finally, the responsible N exported according to judging unit 62 of multiplexer 66 ₁, in the output by electrical combination 65A ~ 65H, select correct cloth woods value B ₁.

As shown in Figure 6, the input signal that multiplier 61A receives is (R ₀-1) but not R ₀.In practice, (R ₀-1) computing can be incorporated in and previously produce R ₀reorganization procedure in, save a subtracter by this.

Refer to Fig. 7.Except the electrical combination 60 shown in Fig. 6, multiplexer 67A ~ 67C, 68A ~ 68B and reformer unit 69 as shown in Figure 7 can also be comprised according to the decoder module 20 in one embodiment of the invention.Multiplexer 67A is responsible for the N produced according to electrical combination 60 ₁s as shown in Figure 6 _{1_00}~ S _{1_07}in select corresponding to this N ₁s ₁.Multiplexer 67B is responsible for according to N ₁by V ₀and { V ₀, nbit (1) } ... { V ₀, nbit (7) } etc. select corresponding to this N in eight numerical value ₁v ₁.Multiplexer 67C is responsible for according to N ₁by S ₀_ m1*2+1 ~ S ₀select corresponding to this N in eight numerical value such as _ m1*128+127 ₁r ₁.

Subsequently, multiplexer 68A can according to the B of electrical combination 60 generation ₁select to correspond to cloth woods value B ₂r ₂initial value R _{2 (0)}should be S ₁or R ₁with S ₁difference.Multiplexer 68B can according to B ₁select to correspond to cloth woods value B ₂v ₂initial value V _{2 (0)}should be V ₁or V ₁with S ₁difference.Above-mentioned initial value R _{2 (0)}and V _{2 (0)}be provided to reformer unit 69, determine to correspond to cloth woods value B for reformer unit 69 ₂r ₂, V ₂and N ₂.According to the N that reformer unit 69 exports ₂and the N that previous circuit combination 60 produces ₁, update module 26 can determine the content by how upgrading buffer 28, and its update mode with reference to previous explanation, can repeat no more.

In like manner, cloth woods value B ₀be 1 eight kinds of situations also can be summarized as other eight groups of different relational expressions, and be implemented as electrical combination similar to Figure 6, circuit integrated with Fig. 7.That is, equally through the numerical value S that this defines ₀_ m1, the present embodiment can simplify cloth woods value B simultaneously ₀n is judged when being 1 ₁value and decision cloth woods value B ₁judgement formula, make the hardware that the present embodiment can be less produce cloth woods value B ₁and the judgement of relevant parameter.Fig. 8 integrates the circuit example containing 16 kinds of possibilities.As shown in Figure 8, numerical value (R ₀-1) S is deducted ₀the difference of _ m1 is further defined as S ₀_ m2, judges N in order to simplify ₁value and decision cloth woods value B ₁judgement formula.Judging unit 62 in this example can according to numerical value S ₀_ m1 and S ₀_ m2 ₀judge cloth woods value B ₀be 1 or 0, and N ₁be which numerical value in 0 ~ 7.For example, Ruo Bulin value B ₀be 1 and N ₁=0, represent R ₁initial value R _{1 (0)}equal (R ₀-S ₀) and be more than or equal to 128.Therefore:

R ₀-S ₀＝R ₀-(1+S ₀_m1)＝(R ₀-1)-S ₀_m1≥128。(formula nine A)

Formula nine A can be rewritten as:

S ₀_m2＞127。(formula nine B)

If numerical value S ₀_ m1 and R ₀box-like nine B of relation character described in person, judging unit 62 can judge cloth woods value B ₀be 1 and N ₁=0.

In addition, V ₁initial value V _{1 (0)}equal (V ₀-S ₀), and reorganization procedure need not adjust R _{1 (0)}and V _{1 (0)}.Then at relatively V ₁and S ₁to determine cloth woods value B ₁when being 1 or 0, judge whether following relationship is set up:

$V_0-S_0\≥?1+\frac{(R_1-1)*P_M}{256}=1+\frac{(R_0-S_0-1)*P_M}{256}.$ (formula nine C)

Formula nine C can be rewritten as:

$V_0-S_0>?\frac{S_0\_m2*P_M}{256}.$ (formula nine D)

Other seven groups of cloth woods value B ₀be 1 and N ₁=1 ~ 7 relational expression can the rest may be inferred.

The 3rd adjustment unit 70 in Fig. 8 is in order to according to numerical value S ₀_ m2 calculates S ₀_ m1*2+1, S ₀_ m1*4+3, S ₀_ m1*8+7, S ₀_ m1*16+15, S ₀_ m1*32+31, S ₀_ m1*64+63, S ₀seven numerical value such as _ m1*128+127 are how many respectively.The cloth woods value B provided according to judging unit 62 is responsible for by multiplexer 66 in this example ₀and numerical value of N ₁select corresponding cloth woods value B ₁.In like manner, corresponding to this cloth woods value B ₀and numerical value of N ₁s ₁, V ₁, R ₁the cloth woods value B that also can provide according to judging unit 62 ₀and numerical value of N ₁be selected, produce cloth woods value B for subsequent conditioning circuit ₂in time, uses.

Circuit example one of after Fig. 9 illustrates and to be simplified by Fig. 8.In this example, cloth woods value B ₀be 1 or 0 to be first judged, determine numerical value of N by judging unit 62 more subsequently ₁.Thereafter each adjustment unit, multiplier, divider, comparator are all for cloth woods value B ₀be 1 or 0 two kind of situation share.Therefore, cloth woods value B ₀be used to control multiple multiplexer, select by the numerical value of input judging unit 62, each multiplier, each comparator why.The Detailed Operation mode of the circuit in Fig. 9 with reference to previous cases, can repeat no more.

From above example, according to result issuable in decode procedure, decoder module 20 can be disassembled as organizing circuit more, calculates the Output rusults corresponding to various possibility simultaneously.For the circuit shown in Fig. 8, need not wait for that the reformer unit 12E as Fig. 1 determines V ₁, R ₁why continue to produce cloth woods value B ₁.By this, the work period T of cloth woods entropy decoder 200 can be shortened further, promotes its operating frequency.It should be noted that as shown in Figure 8, the element that the above-mentioned mode disassembling circuit computing only adopts is multiplier, divider, comparator mostly, and such circuit framework is simple compared to the circuit additionally containing many adder-subtractors, can saving chip area when realizing.

Be a kind of cloth woods entropy decoding method being applied to image playing system according to another embodiment of the present invention, Figure 10 is its flow chart.This image playing system comprises a buffer, in order to the bit segment in this bit element flow temporary.First, step S11 has the first bit amount N for utilizing in this bit segment ₁one first section, produce correspond to the first cloth woods value B ₁numerical value V ₁.For the situation that Fig. 4 illustrates, the first bit amount N ₁produce in the reorganization procedure of work period T0 back segment.Then, step S12 for produce the first cloth woods value B in the first work period ₁.Step S13 utilizes in this bit segment to have second bit amount N ₂one second section, produce correspond to the second cloth woods value B ₂numerical value V ₂.For Fig. 4, second bit amount N ₂produce in the reorganization procedure of work period T1 leading portion.Subsequently, step S14 is according to the first bit amount N ₁and second bit amount N ₂from this bit element flow acquisition one new bit segment.The step S15 that simultaneously can carry out with step S14 continues in the first work period, produce the second cloth woods value B ₂.

Then, step S16 corresponds to the 3rd cloth woods value B for producing ₃numerical value V ₃.Step S17 optionally adjusts numerical value V after buffer is updated according to this new bit segment ₃.For Fig. 4, numerical value V ₃produce in the reorganization procedure of work period T1 back segment, and the time upgrading buffer can be arranged at work period T2 start front or start time; After buffer is updated, can according to numerical value V ₃required bit amount optionally adjusts numerical value V ₃.Step S18 is subsequently exactly the numerical value V utilized in work period T2 after by selective updating ₃produce the 3rd cloth woods value B ₃.

Flow process shown in Figure 10 can be implemented in various cloth woods entropy decoder, is not limited with circuit frameworks such as Fig. 1 or Fig. 6.

By the above detailed description of preferred embodiments, it is desirable to clearly to describe feature of the present invention and spirit, and not with above-mentioned disclosed preferred embodiment, category of the present invention is limited.On the contrary, its objective is wish to contain various change and tool equality be arranged in the present invention institute in the category of the scope of the claims applied for.

Claims (9)

1. a cloth woods entropy decoder, has the bit element flow about image data in order to decoding, comprises:

One decoder module, produce one according to this bit element flow and open beginning cloth woods value, one first cloth woods value and one second cloth woods value, this decoder module needs one first bit amount when producing first numerical value corresponding to this first cloth woods value, and a second bit amount is needed in time producing the second value corresponding to this second cloth woods value, wherein this first cloth woods value, this second value, this second cloth woods value and are fixed tentatively third value corresponding to one of one the 3rd cloth woods value and are produced in the same work period;

One buffer, in order to the bit segment in this bit element flow temporary, for this decoder module, this bit segment contains this first bit amount and this second bit amount; And

One update module, captures a new bit segment according to this first bit amount and this second bit amount from this bit element flow, and produce the third value step corresponding to the 3rd cloth woods value at this decoder module before, upgrades this buffer according to this new bit segment;

Wherein this decoder module optionally adjusts this tentative third value corresponding to the 3rd cloth woods value after this buffer is updated.

2. cloth woods entropy decoder as claimed in claim 1, it is characterized in that, this first bit amount and this second bit amount are at most 7 bits separately, and the capacity of this buffer is 16 bits.

3. cloth woods entropy decoder as claimed in claim 1, it is characterized in that, this first bit amount has N kind possibility, and N is a positive integer, and this decoder module comprises:

One preliminary arithmetic element, corresponds to this scope opening beginning cloth woods value in order to basis and a probability produces the rear separation number of an adjustment;

One judging unit, in order to determine this first bit amount according to separation number after this adjustment;

One first adjustment unit, in order to produce (N-1) individual term of reference according to separation number after this adjustment;

One second adjustment unit, in order to according to correspond to this open one of beginning cloth woods value open the beginning numerical value produce (N-1) individual referential data;

N group counting circuit, in order to according to separation number after this adjustment, to open beginning cloth woods value corresponding to this this open beginning numerical value, should (N-1) individual term of reference and N number of candidate Bu Lin value should be produced by (N-1) individual referential data; And

One first multiplexer, in order to select this second cloth woods value according to this first bit amount in this N number of candidate Bu Lin value.

4. cloth woods entropy decoder as claimed in claim 3, is characterized in that, this N group counting circuit produces one separately with reference to separation number, and this decoder module comprises further:

One second multiplexer, in order to select the separation number corresponding to this first cloth woods value in this N number of reference separation number according to this first bit amount;

One the 3rd multiplexer, in order to this first numerical value opening beginning numerical value according to this first bit amount from this corresponding to that this opens beginning cloth woods value and should select in (N-1) individual referential data corresponding to this first cloth woods value; And

One the 4th multiplexer, in order to according to this first bit amount separation number and the scope that should select in (N-1) individual term of reference corresponding to this first cloth woods value after this adjustment.

5. cloth woods entropy decoder as claimed in claim 3, it is characterized in that, N equals eight.

6. cloth woods entropy decoder as claimed in claim 3, it is characterized in that, this first adjustment unit utilizes one or more shift unit to produce these terms of reference.

7. be applied to a cloth woods entropy decoding method for an image playing system, in order to a bit element flow of decoding, this image playing system comprises a buffer, and in order to a bit segment in this bit element flow temporary, this coding/decoding method comprises:

Utilize in this bit segment one first section with one first bit amount, produce one first numerical value corresponding to one first cloth woods value;

One first cloth woods value is produced in one first work period;

Utilize in this bit segment one second section with a second bit amount, produce the second value corresponding to one second cloth woods value;

A new bit segment is captured from this bit element flow according to this first bit amount and this second bit amount;

This second cloth woods value is produced in this first work period;

Produce the tentative third value corresponding to one the 3rd cloth woods value; And

In one second work period, utilize one to be produced the 3rd cloth woods value by the tentative third value optionally adjusted;

Wherein, correspond between the third value step of the 3rd cloth woods value in stream this new bit segment step of acquisition and generation, also comprise and upgrade this buffer according to this new bit segment, then optionally adjust this tentative third value.

8. cloth woods entropy decoding method as claimed in claim 7, it is characterized in that, this first bit amount and this second bit amount are at most 7 bits separately, and the capacity of this buffer is 16 bits.

9. cloth woods entropy decoding method as claimed in claim 7, it is characterized in that, the time upgrading this buffer can be arranged at when this bit element flow has captured this new bit segment or when this second work period starts.