CN1016130B - The encoder of MAC color TV and the frequency of decoder take place - Google Patents
The encoder of MAC color TV and the frequency of decoder take placeInfo
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- CN1016130B CN1016130B CN 85107649 CN85107649A CN1016130B CN 1016130 B CN1016130 B CN 1016130B CN 85107649 CN85107649 CN 85107649 CN 85107649 A CN85107649 A CN 85107649A CN 1016130 B CN1016130 B CN 1016130B
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Abstract
In composite analogy component type (MAC) color system, at receiving terminal, the MAC conversion of signals becomes video burst and sync signal, and its colored carrier frequency is 227.5f.Select various frequencies by following relational expression, can the required frequency generator of simplified receiver
In the formula
f
oIt is master clock frequency
f
1It is the luma samples frequency
f
2It is the chroma samples frequency
f
4It is the MAC sample frequency
F is the horizontal line frequency
And n and k are positive integers.
Description
The present invention is about the transmission and the reception of color TV.
In the U.S., carry out colour broadcasting according to the compound standard of national television system committee.This standard-required pictorial information separated into two parts: brightness (or briliancy) and colourity (or colored).Fig. 1 is the width of cloth-frequency curve chart, and the TSC-system video burst and sync signal 10 that typically comprises luminance signal 12 and carrier chrominance signal 14 is described.(chrominance information of videoblankingsync is loaded in and pays on the carrier wave.Other composite signal has the Sequential Color and Memory system of French usefulness, the Phase Alternation Line system of other regional usefulness of Europe).The bandwidth of this signal is common 6MHZ, and wherein pix carrier 16 is 1.25MHZ, is higher than the low side of bandwidth.Monochrome information directly is modulated on the pix carrier 16, and chrominance information is modulated onto colored paying on the carrier wave 18.Colored frequency of paying carrier wave 18 is that the 3.579545MHZ(audio signal of NTSC regulation is loaded on another pair carrier wave 20, high-end near bandwidth).
On Fig. 1, district's particular importance of alphabetical A mark is because it represents the overlapping part of luminance signal 12 and carrier chrominance signal 14.Because by the filtering frequency division multiplex signal, luminance and chrominance information is separated, the overlapping that resembles two kinds of signals the A district can cause some problems.If, at receiving terminal, need complete separating luminance and carrier chrominance signal, then Bi Yao filtering meeting makes two kinds of some information of dropout.Aspect other, as not allowing drop-out, then luminance and chrominance information phase mutual interference.In addition, the each several part of the TV signal of TSC-system transmits on different frequency, in transmission course the influence of phase shift also different, this just causes signal degradation.Also has the restriction of the narrow colored bandwidth that available colour information is seriously permitted.
For addressing these problems, be developed into a kind of MAC colour television system (MAC) that is called, this MAC colour TV signal is described as Fig. 2, and it is the width of cloth-time curve chart of a video line, and the time interval is 63.53 μ S.10.9 initial μ S are horizontal blanking intervals (HBI) 22, during this period transmission diagram image information not.Carrier chrominance signal 24 and luminance signal 26 are right after after HBI, and the both is compressible, between carrier chrominance signal 24 and luminance signal 26 0.28 buffer zone are arranged, and prevent the mutual interference of two kinds of signal phases.
Obtain MAC colour TV signal shown in Figure 2, at first produce common luminance and chrominance information (for example producing common NTSC signal or other videoblankingsync), sample respectively then and store, with the luma samples frequency brightness is sampled, and it is stored in the luminance memorizer; With the chroma samples frequency colourity is sampled, and it is stored in the colourity memory; Then the sampling of brightness or the colourity time of carrying out is gone up compression, method be with separately sample frequency with the signal write memory, with a higher frequency it is read.For effectively reading in the row interval,, so just form MAC signal shown in Figure 2 with a multiplexer gating luminance memorizer or colourity memory.As needs, audio sample can transmit during HBI, and with the identical way of video sampling, in multiplexed MAC signal, the speed of all samplings is called the MAC sample frequency by multi channel selecting (may be compressed) in these samplings.
Though MAC form shown in Figure 2 has overcome the problem of videoblankingsync shown in Figure 1, these problems are replaced by some other difficulties, in MAC system in the past, concrete device with satisfied image quality uses the luma samples frequency of 13.50MHZ with 3: 2 ratio brightness to be compressed, therefore, the MAC sample frequency is 20.25MHZ, but NTSC horizontal line frequency f(delegation is 63.56 μ S) be 0.01573MHZ, it is 1/1287 of a MAC sample frequency.Thereby, because many receivers all will produce this three kinds of frequencies, every receiver must adopt the frequency generating circuit of complicated costliness, the colored frequency of paying carrier wave and producing other needs that is used to regenerate, so (it is 227.5f that all video burst and sync signals have used colored carrier frequency to increase the price of system widely
H; But f in every kind of system
HBe different, therefore, only in the NTSC system, colored frequency of paying carrier wave is 3.579545MHZ(227.5f
H).
In MAC system in the past, another kind of concrete device uses 10.74MHZ(682.5f
H) the luma samples frequency, compress brightness with 4: 3 ratio, therefore, the MAC sample frequency is 14.32MHZ(910f
H), except that complicated frequency generating circuit, because the luma samples frequency is low, the picture quality of this system can not be satisfactory, therefore, do not satisfy the Nyqist criterion of commercial requirement and required luminance frequency.
In MAC system in the past, the third concrete device uses 21.48MHZ(1365f
H) the MAC sample frequency and luminance compression than 5: 4, thereby the luma samples frequency is 17.18MHZ(1092f
H), this can provide gratifying picture.But, still need complicated frequency generating circuit.Also have, all fill in effective row with equal width as brightness and colourity, for example NTSC effectively goes (52.38 μ S), and then the colourity compression ratio must be 5: 1, because noise, the quality of carrier chrominance signal is unsafty.For fear of noise problem, change the colourity compression ratio into 15: 4, but increase the complexity of frequency generating circuit, and luminance and chrominance information will exceed effective row, enter the horizontal blanking interval, the result in every video line, leaves the deficiency of time of audio-frequency information for.
Except that the complexity that frequency takes place, also require in every receiver, to produce 227.5f
H(3.579545MHZ, NTSC) colour of frequency is paid carrier wave.Therefore need technology simple and easy, that qurer produces pair carrier wave.Because reference receiver is made the reception videoblankingsync, it can not directly receive the MAC TV signal.In order to transmit, at first the MAC conversion of signals is become composite signal (for example NTSC, PAL or SECAM) at receiver end.
The objective of the invention is, simplify frequency generating circuit and reduce its cost, in order to transmit the MAC colour TV signal.This circuit is positioned at the receiving terminal of communication system, with MAC conversion of signals videoblankingsync.
Another object of the present invention is, with sufficiently high frequency sampling brightness and colourity, to obtain gratifying image.
Another object of the present invention is so to compress brightness and colourity, makes both signals fill in effective row, and does not enter HBI(therefore, and the time enough transmit audio information is arranged in the HBI interval).
Another object of the present invention is: brightness or colourity are not compressed to such degree, image quality under this degree is because the cause of noise makes us dissatisfied.
The present invention reaches above these and other purpose by setting up a class frequency (as sample frequency or other purposes).These frequencies are correlated with, can from single master clock frequency, come out with quite low integral frequency divisioil, owing to do not have the frequency multiplication problem (if some frequency of selecting can not be got from master clock frequency definitely, the frequency multiplication problem is then arranged), the phase-lock loop of a single control master clock frequency of needs.This characteristics of the present invention have reduced the cost of every receiver widely.
Learn that in order to satisfy commercial the requirement and the Nyquist criterion, obtain gratifying qualitatively TV signal, the luma samples frequency should be higher than 12MHZ at least, and the chroma samples frequency minimum should be 5MHZ.Realize the upper limit of sample frequency substantially by the integrated circuit skill of the existing cheapness of about 20MHZ, therefore, when transmission MAC TV signal, fundamental frequency (brightness or colourity) and compression ratio be to be amassed (being the MAC sample frequency) and can not cross greater than this numerical value.
Because audio frequency is accompanied by video burst and sync signal, finally send receiver to, so audio sample is included within the MAC colour TV signal.Thereby audio sampling frequency also is chosen to the aliquot of master clock frequency.
As need fax, receiver should produce the signal of nearly 6MHZ, can utilize " dot matrix " fax character generator of standard like this.Equally, the definite frequency of this signal should be the aliquot of master clock frequency.
Relation between the frequency that the present invention selects is as follows:
f
0/n=(3/2)f
1=3f
2=65f
3=f
4=227.5kf
H
N and k are positive integers in the formula, f
HIt is the horizontal line frequency.
Can find out that from these coefficients each signal (comprises 227.5f
HColour pay carrier wave) can get from master clock frequency fully, divide ratio is little positive integer.(in some cases, several such frequency dividers, for example with the master clock rate divided by 5n, again divided by 13, promptly draw audio sample signal f
3) this just allows receiver only to use single phase-lock loop or simple frequency divider, has simplified frequency generating circuit widely.
Obtain gratifying image quality, must select luma samples frequency (f
1) and chroma samples frequency (f
2) above essential minimum (should be 12MHZ and 5MHZ mutually).
Luminance compression is than (f
4/ f
1) be 3: 2, colourity compression ratio (f
4/ f
2) be 3: 1, therefore the luminance and chrominance information after the compression all in effectively going, can not enter the HBI district, yet both compressions is not too high, can not produce unacceptable visual noise.
In above-mentioned restriction, MAC sample frequency f
4Can be very low, receiver guarantees the total low cost of hardware with regard to the video a/d converter or the CCD of available existing low price like this.
The present invention also provides center this machine encoder, and the colour TV signal that it will comprise brightness and colourity converts the MAC colour TV signal to, and decoder (for every receiver) also is provided, and it converts the MAC colour TV signal to video burst and sync signal.This signal also can be with the more superior farther path of MAC form transmission.
Encoder receives and to comprise the brightness of separation and the TV signal of chromatic component, and these components are sampled with suitable (brightness and colourity) sample frequency in the known manner, and luma samples is by compression in 3: 2, and method is, with luma samples with f
1Frequency (luma samples frequency) write memory is again with f
4Frequency (MAC sample frequency) is read.Chroma samples was by compression in 3: 1, and method is with f
2Frequency (chroma samples frequency) write memory is again with f
4Frequency is read.Alternately these samplings are read (or comprise the signal of other needs, for example audio sample) in the memory with multiplexer, generation MAC colour TV signal sends each receiver to.
At every receiver end, decoder comprises demultiplexer, and this demultiplexer is isolated some compositions from the MAC signal.Inverse process by above-mentioned compression recovers brightness and colourity, and audio frequency and other signal also are resumed.
In the known manner, chroma samples is used to modulate decoder and produces 227.5f
HThe colored carrier wave of paying.Pair carrier wave of luma samples that is resumed then and modulation and the suitable blanking signal that reaches synchronously are combined into video burst and sync signal.
In the HBI interval, can transmit some voice-grade channels with the time-division multiplex recombiner, same, by well-known mode, (VBI) can transmit information via telex at vertical blanking interval.Teletype code recovers in receiver and is defeated by character generator, and character generator produces the character that is used to be presented on the TV screen.
The accompanying drawing summary
Fig. 1 is the width of cloth-frequency curve chart, typical in brief NTSC colour TV signal.
Fig. 2 is the width of cloth-time curve chart of a video line of typical MAC colour TV signal.
Fig. 3 is the width of cloth-time curve chart according to a video line of MAC colour TV signal of the present invention.
Fig. 4 is the calcspar of the encoder used of the present invention.
Fig. 5 is the calcspar of multiple frequency generator circuit, is used for encoder and decoder.
Fig. 6 is the calcspar of the decoder used of the present invention.
Fig. 7 is the line storage calcspar, is used for compression and recovers luminance and chrominance information.
Fig. 8 is during luminance recovery, the input and output signal figure of the line storage of Fig. 7.
Table 1 provides the frequency that most preferred embodiment of the present invention is selected for use.Though it is TSC-system that the colour that the present invention proposes is paid carrier wave, 3.579545MHZ, and the MAC signal changes into the NTSC signal at receiving terminal, also is applicable to PAL and Sequential Color and Memory system.
Table 1
The signal frequency frequency dividing ratio
Master clock (f
0) 42.95MHZ=2730f 1
Luma samples (f
1) 14.32MHZ=910f 1/3
Chroma samples (f
2) 7.16MHZ=455f 1/6
Audio sample (f
3) 0.33MHZ=21f 1/130
MAC (the f that samples
4) 21.48MHZ=1365f 1/2
Fax generator (f
5) 0.14MHZ=390f 1/7
The colored carrier wave 3.579545MHZ=227.5f 1/12 that pays of NTSC
(frequency f
3, also can be 0.20MHZ or 13f
H, i.e. f
01/120)
Fig. 3 is according to the width of cloth of a video line of the present invention transmission curve chart for the moment, and identical among the width of HBI22 and the NTSC is 10.9 μ S in fact.Carrier chrominance signal 24 was by compression in 3: 1, and width only is 17.46 μ S, and luminance signal 26 was by compression in 3: 2, and width is 34.92 μ S.The shield segment that one 0.28 μ are arranged separates two signals.
Fig. 4 is the encoder block figure that the present invention uses, and three colour TV signal-brightness (Y) and two color difference signals (R-Y and B-Y) correspondingly pass through low pass filter 100a from common color TV source, 100b and 100c filtering.Filtered colour TV signal is sampled among 102b and the 102c at A/D converter 102a, and it is 910f that the sampling speed of luminance signal is considered
H, the sampling rate of each colour signal is 455f
H
Then, as mentioned above, digital brightness and carrier chrominance signal are compressed, with luma samples frequency 910f
HBrightness data is write luminance memorizer 110a(CCD line storage) again with MAC sample frequency 1365f
HBrightness data is read from memory read.Again with chroma samples frequency 455f
HChroma data is write colourity memory 110b, (also being the CCD line storage), however be 1365f again with the frequency
HSample frequency read.
In the colour TV signal processing procedure, the audio signal of following also is sampled and compresses, and 4 voice-grade channels are sampled and digitlization in 4 Delta modulator 112a-112d, and sample frequency is 21f
H(as 6 voice-grade channels of need, then sample frequency is 13f
H) replace 4 voice-grade channels of being modulated by Delta of gating by multichannel recombiner 114, and be compressed to 455f
HAfter the compression, in sample circuit 116, be MAC sample frequency 1365f with the sample frequency
HAudio frequency is sampled again.
On Fig. 4, there is the arrow of " VBI " mark to be illustrated in the interval information transmitted of VBI, synchronously, clock and fax.Produce these information and it is sent into multiplexer 118 in common mode with the MAC sample frequency.
Fig. 5 is the circuit diagram of multiple frequency generator, is used for encoder and decoder.Master clock 200 comprises phase-lock loop, produces 2730f
HMaster clock signal, three frequency dividers of this signal input, frequency divider 202 carries out frequency division 2 times with master clock signal, frequency divider 206 carries out frequency division 3 times, frequency divider 206 carries out frequency division 7 times.The output 910f of frequency divider 204
HIt is the luma samples signal.The output 390f of frequency divider 206
HIt is the fax generator signal.The 1365f that frequency divider 202 produces
HSignal is the MAC sampled signal, and it is again by frequency divider 208 and 210 frequency divisions.Frequency divider 208 carries out frequency division three times with the MAC sampled signal, produces 455f
HThe chroma samples signal, simultaneously frequency divider 210 is done frequency division 65 times, produces 21f
HThe audio sample signal.
Fig. 6 is the decoder calcspar that the present invention uses.At first, the MAC TV signal enters demultiplexer 300, and it is with brightness, carrier chrominance signal and audio frequency, and synchronously, clock and teletype signal are separated.Luminance signal enters luminance memorizer 302(CCD line storage), signal is resumed therein, and then through low pass filter 304 filtering output, thereby the luminance signal of simulation enters output interface 306.Recover the required sampled signal of luminance signal and produce, supply with luminance memorizer 302 by two clock drivers 310 by clock generator 308.
The carrier chrominance signal of demultiplexer 300 output also is the capable storage of CCD at colourity memory 312(also) in recover, export the color difference signal that two-way separates, pass through low-pass filtering 314 filtering then and enter output interface 306.Clock generator 308 produces the sampled signal that needs and supplies with luminance memorizer 312 by three clock drivers 310.
Demultiplexer 300 also will not constitute the signal of brightness and colourity and separate from the MAC TV signal.These signals comprise audio frequency, fax and synchronous and clock signal.Audio frequency, fax and synchronizing signal are by low pass filter 318 input demultiplexers 316; Simultaneously, the clock signal of fixed frequency is by band pass filter 320 input demultiplexers 316, demultiplexer 316 is defeated by demultiplexer 322 with these Signal Separation with audio signal, and synchronous and clock signal are defeated by clock and synchronization recovery circuit 324 and clock generator 308.Audio signal from demultiplexer 316 is divided into 4 the tunnel in voice-frequency-multichannel separator 322, again through 326 outputs of analogue audio frequency processor.Teletype signal is defeated by character generator 328 by clock and synchronization recovery circuit 324.Decoder is worked under microprocessor 330 control, microprocessor by bidirectional bus 334,338 and 336 with clock and synchronization recovery circuit 324, fax character generator 328 and random access memory 332 are communicated by letter.
Fig. 7 is the calcspar of line storage, and it is used for compression or recovers luminance and chrominance information, and this line storage is the storage device 110a of Fig. 4, typical case's representative of 302,312 of 110b and Fig. 6.Line storage plays the luminance recovery effect.During recovering brightness, the input and output signal of the line storage of Fig. 7 is drawn on Fig. 8.When the MAC TV signal arrived, clock 1 writing line memory 400 was totally 750 luma samples, and sample frequency is MAC sample frequency 1365f
H, clock 2 reads into the output row with the sampling of line storage 402 storages simultaneously, and speed is 910f
HDuring next video line, clock 2 is with 750 luma samples writing line memories 402, and speed is 1365f
H, the luma samples that while clock 1 will be stored in the line storage 400 reads into the output row, and speed is 910f
HIt is similar to recover to shorten the operating principle of sampling, and Zhong Pin is 1365f
HAnd 455f
H
Though utilize clear in detail the of the present invention concrete device of accompanying drawing as illustration, should understand, the present invention is not limited to the details in the concrete device, and in scope of the present invention (or spirit), the personnel that are skilled in technique can also make various modifications and remodeling.
Claims (16)
1, a kind of improved communication means is used for transmission and contains brightness and chrominance information, and is attended by the TV signal of audio-frequency information, and the old step of the method comprises: the sampling monochrome information, frequency is f
1The sampling chrominance information, frequency is f
2Sampled audio information, frequency are f
3Compression brightness and chroma samples, frequency is f
4The compressed audio sampling; Combination brightness, colourity become multi-channel analog composite type (MAC) TV signal with audio sample; From MAC TV signal separating luminance, colourity and audio sample; Recover luma samples, frequency is f
1Recover chroma samples, frequency is f
2Recover audio sample, frequency f
3The chroma samples modulation 227.5f that recovers
HPay carrier wave; The carrier wave of paying of luma samples that combination recovers and modulation becomes to mix TV signal; Output is with the mixing TV signal of the audio sample that recovers; And producing the master clock signal, frequency is f
0Here improved step comprises:
Select f
0, f
1, f
2, f
3And f
4, satisfy relational expression
(f
o)/(n) = 3/2 f
1=3f
2=65f
3=f
4=227.5kf
H
N and k are positive integers in the formula,
From master clock signal f
0Middle frequency division obtains frequency f
1, f
2, f
3And f
4
2, in communication system, the device of multiple frequency is provided, be used to transmit and contain brightness, chrominance information and with the TV signal of audio-frequency information, the old equipment of this communication system comprises sampling apparatus, sampling brightness and chrominance information, frequency is f
1And f
2; Compression set becomes the frequency of brightness and chroma samples into f
4; Multiplex machine is with the brightness and chroma samples channeling simulation composite type (MAC) TV signal of compression; Multi-channel separator is isolated brightness and chroma samples from the MAC TV signal; Recovery device becomes the brightness and the chroma samples frequency of separating into f
1And f
2The color modulation device is with the chroma samples modulation 227.5f that recovers
HPay carrier wave; Output device is formed the mixing TV signal with the luma samples of recovery and the carrier wave of paying of modulation, it is characterized in that the above-mentioned device of frequency that provides comprises:
Master clock, the generation frequency is f
0Master clock signal;
Frequency divider, to above-mentioned sampling apparatus, compression set, recovery device, the color modulation device provides the signal that draws from the master clock signal frequency division, and frequency is f
1, f
2, f
4And 227.5f
H, here
(fo)/(n) = 3/2 f
1=3f
2=f
4=227.5kf
H
N and k are positive integers in the formula.
3, a kind of encoder, the TV signal that it will contain brightness and chrominance information converts composite analogy component type TV signal (MAC) to, converts thereof into videoblankingsync by decoder again, and above-mentioned encoder comprises:
Sampling apparatus, the sampling monochrome information, frequency is f
1, the sampling chrominance information, frequency is f
2;
Compression set becomes f with the frequency of brightness and chroma samples
4;
Multiplex machine is combined into the MAC TV signal with brightness and chroma samples after the compression; It is characterized in that comprising:
Master clock, the generation frequency is f
0Master clock signal; And
Frequency divider, providing the frequency that draws from the master clock frequency division to sampling apparatus and compression set is f
1, f
2And f
4Signal,
Wherein,
(f
o)/(n) = 3/2 f
1=3f
2=f
4=227.5kf
H
N and k are positive integers in the formula.
4, according to claim 3, the n=2 of encoder, k=6.
5, according to claim 3, encoder further comprises the device that is used to receive information via telex, and above-mentioned multiplex machine is incorporated information via telex into the MAC TV signal.
6, according to claim 3, audio-frequency information is accompanied by TV signal, above-mentioned sampling apparatus sampled audio information, and frequency is f
3, above-mentioned compression set changes the frequency of audio sample, and the audio sample after above-mentioned multiplex machine will compress is incorporated the MAC TV signal into, and above-mentioned frequency divider provides the sampled signal that draws from the master clock frequency division to above-mentioned sampling apparatus, and frequency is f
3, have
(fo)/(n) =65f
3
7, according to claim 3, audio signal is followed TV signal, above-mentioned sampling apparatus sampled audio information, and frequency is f
3, above-mentioned compression set changes the frequency of audio sample, and the audio sample after above-mentioned multiplex machine will compress is incorporated the MAC TV signal into, and above-mentioned frequency divider provides the sampled signal that is drawn by the master clock frequency division to above-mentioned sampling apparatus, and frequency is f
3, have
(f
o)/(n) =105f
8, a kind of decoder, it will contain frequency is f
4Brightness and the multiplexed component type TV signal (MAC) of chroma samples convert videoblankingsync to, above-mentioned decoder comprises:
Demultiplexer is isolated brightness and chroma samples from the MAC TV signal;
Recovery device becomes the frequency of compressed luma samples and chroma samples into f
1And f
2;
The color modulation device is with the chroma samples modulation 227.5f that recovers
HPay carrier wave;
Output device is formed multiplexing TV signal with the luma samples of recovery and the carrier wave of paying of modulation; It is characterized in that comprising:
Master clock, the generation frequency is f
0Master clock signal; And
Frequency divider, to above-mentioned recovery device, it is f that the color modulation device provides the frequency that draws from the master clock frequency division
1, f
2, f
4Signal and 227.5f
H, wherein
(f
o)/(n) = 3/2 f
13f
2=f
4=227.5kf
H
N and k are positive integer in the formula.
9, according to claim 8, the n=2 of decoder, k=6.
10, according to claim 8, MAC TV signal in the decoder comprises information via telex, and above-mentioned demultiplexer is separated information via telex from the MAC TV signal, and above-mentioned decoder also comprises the fax character generator, be connected to above-mentioned output device, the generation frequency is f
5The fax character, above-mentioned output device is incorporated the fax character into the mixing TV signal, above-mentioned frequency divider provides the signal that draws from the master clock frequency division to above-mentioned fax character generator, frequency is f
5, have
(f
o)/(n) =3-1/2f
5
11, according to claim 3, the parameter of encoder
f
0=42.96MHZ
f
1=14.32MHZ
f
2=7.16MHZ
f
3=0.33MHZ
f
4=21.48MHZ
12, according to claim 3, the parameter of encoder
f
0=42.96MHZ
f
1=14.32MHZ
f
2=7.16MHZ
f
3=0.20MHZ
f
4=21.48MHZ
13, according to claim 8, the parameter of decoder
f
0=42.96MHZ
f
1=14.32MHZ
f
2=7.16MHZ
f
3=0.33MHZ
f
4=21.48MHZ
14, according to claim 8, the parameter of decoder
f
0=42.96MHZ
f
1=14.32MHZ
f
2=7.16MHZ
f
3=0.20MHZ
f
4=21.48MHZ
15, according to claim 8, in decoder, the MAC TV signal comprises audio sample, and above-mentioned multi-channel separator is isolated audio sample from the MAC TV signal, and above-mentioned recovery device becomes audio sampling frequency into f
3, the audio sample that above-mentioned output device output recovers is incorporated the mixing TV signal into, and above-mentioned frequency divider provides the signal that draws from the master clock signal frequency split, frequency f to above-mentioned recovery device
3, have
(fo)/(n) =65f
3
16, according to claim 8, in decoder, the MAC TV signal comprises audio sample, and above-mentioned multi-channel separator is isolated audio sample from the MAC TV signal, and above-mentioned recovery device becomes audio sampling frequency into f
3, the audio sample that above-mentioned output device output recovers is incorporated the mixing TV signal into, and above-mentioned frequency divider provides the signal that draws from the master clock signal frequency split to above-mentioned recovery device, and frequency is f
3, have
(f
o)/(n) =105f
3o
Priority Applications (1)
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CN 85107649 CN1016130B (en) | 1985-10-14 | 1985-10-14 | The encoder of MAC color TV and the frequency of decoder take place |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN 85107649 CN1016130B (en) | 1985-10-14 | 1985-10-14 | The encoder of MAC color TV and the frequency of decoder take place |
Publications (2)
Publication Number | Publication Date |
---|---|
CN85107649A CN85107649A (en) | 1987-04-15 |
CN1016130B true CN1016130B (en) | 1992-04-01 |
Family
ID=4795710
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CN 85107649 Expired CN1016130B (en) | 1985-10-14 | 1985-10-14 | The encoder of MAC color TV and the frequency of decoder take place |
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1985
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