CN1294479C - Auto recognition method of simulating video signal mode - Google Patents

Abstract

The present invention provides an automatic recognition method of simulating a video signal mode, which relates to a display technique of a digital plane, particularly to a digital processing technique of simulating a video signal. The present invention calculates display quality in each similar mode and then selects the mode of the highest display quality as a correct display mode. The present invention has the advantages that the present invention not only can accurately recognize the different image modes of HPER, VPER and VLINE, but also accurately recognize the identical and HTOTAL different similar modes of the HPER, the VPER and the VLINE so as to enhance the display quality of a display.

Description

Analog video signal pattern automatic identifying method

Technical field

The present invention relates to the digital plane display technique, particularly the digital processing technology of analog video signal.

Background technology

The digital plane display for can correctly sample, the analog video signal, pattern that must correct identification signal.

The PC analog video signal produces through the D/A conversion, four parameters of HTOTAL of counting that its pattern can be comprised by line number VLINE, the every row that line frequency HPER, field frequency VPER, every frame comprise are unique to be determined, wherein has only the value of HPER, VPER and VLINE to obtain by direct measurement of hardware or calculating.

As prior art, be example with the PC display technique, concrete mode identification method is:

1. search the mode standard table according to HPER, VPER, VLINE, obtain pattern list HTOTAL value;

2. if there is approximate mode, the HTOTAL that obtains is the HTOTAL value of first approximate mode in the mode standard table, and input signal is confirmed as this pattern;

3. there are differences owing to various video cards, the HTOTAL value that in the mode standard table, obtains, may there be nuance with the true HTOTAL value of input signal, the digital plane display all will utilize zero offset capability (comprising the definition that approaches calculating and display quality one by one of HTOTAL value) that the HTOTAL value from pattern list is carried out limited correction, finally obtains the best HTOTAL value of display quality under set pattern;

4. set the A/D transducer according to institute's recognized patterns.

Conventional mode identification method utilizes the corresponding data of various patterns in HPER, VPER, VLINE and the mode standard table of signal to compare, and chooses identical or immediate pattern shows signal.But the PC analog video signal that some pattern is approximate, as 640 * 480@60Hz and 720 * 480@60Hz, or 1024 * 768@75Hz and 1280 * 768@75Hz etc., their HPER, VPER, VLINE are identical, unique difference is exactly that HTOTAL is widely different, so, can not guarantee to discern fully, correctly show with conventional method.

Summary of the invention

Technical matters to be solved by this invention is, a kind of analog video signal pattern automatic identifying method is provided, and can discern display mode more accurately, improves the display display quality.

The present invention solve the technical problem the technical scheme of taking, and a kind of analog video signal pattern automatic identifying method is provided, and calculates the display quality under each approximate mode, chooses the highest pattern of display quality as correct display mode.

The present invention approaches calculating optimum HTOTAL value one by one according to HTOTAL and horizontal resolution; Control the A/D sampled signal with the pattern that best HTOTAL value is determined.

Specifically, the present invention includes following steps:

The search criterion pattern list, if there is no approximate mode then shows, if there is approximate mode, then carries out according to the following steps;

1), approaches the best HTOTAL value of each pattern of calculating one by one according to HTOTAL in each approximate mode and horizontal resolution;

2) difference calculation procedure 1) the display quality value of the best HTOTAL value of each pattern;

3) selecting the HTOTAL of display quality maximal value correspondence is final HTOTAL value;

4) according to the value search criterion pattern list of final HTOTAL, determine final pattern.

The invention has the beneficial effects as follows, not only can accurately discern HPER, VPER, the discrepant image model of VLINE, can also accurately discern HPER, the VPER approximate mode that HTOTAL is different with VLINE is identical, thereby, the display quality of display improved.

Practical test result shows:

1) the approximate analog video signal of pattern, its HPER, VPER, VLINE value are identical, and the HTOTAL value is widely different;

2) analog video signal of different display adapter output model identical, its HPER, VPER, VLINE, HTOTAL value can change within the specific limits.

In the digital plane display system, the pattern of correct identification signal, with appropriate sample frequency the simulating signal of input to be carried out the A/D conversion be basis and the prerequisite that obtains good display quality, for not adopting digital plane display of the present invention, because its pattern-recognition is only finished according to HPER, VPER, VLINE value, can not entirely accurate discern the approximate PC analog video signal of all patterns, mistake appears in feasible HTOTAL differentiation to signal, cause the sample frequency mistake, display quality greatly descends thereupon; And adopt digital plane display of the present invention can adapt to different PC display adapters automatically, because can correctly discern line frequency, approximate mode that field frequency is identical, and make the approximate PC analog video signal of all patterns all obtain correct A/D sample frequency, thereby guaranteed best display quality.

Description of drawings

Fig. 1 is the PC analog video signal waveform synoptic diagram that one embodiment of the present invention relates to.

Fig. 2 is a specific embodiment of the invention process flow diagram.

Embodiment

The PC display adapter has otherness, is exactly that the value of its HPER and VPER is also not exclusively equal when output model identical signal, but in a scope.But pattern HPER different with line frequency, field frequency and the otherness of VPER are compared, and this scope is less, the digital plane display in view of the above and the different pattern of the difference of VLINE identification, as 640 * 480,800 * 600,1024 * 768,1280 * 1024 etc.In this document,, just be called " identical " as long as the value of HPER and VPER changes, can not be considered as in view of the above different mode in proper range.HPER, VPER is identical and PC analog video signal that HTOTAL differs greatly just is called " the PC analog video signal that pattern is approximate ", as 1024 * 768@60Hz and 1280 * 768@60Hz.Can judge with the normal mode recognition methods whether a signal exists approximate display mode, if there is no approximate mode, the digital plane display is shows signal directly, if there is approximate display mode, will use pattern automatic identifying method of the present invention.

The PC analog video signal produces through the D/A conversion, and it is not desirable simulating signal.PC analog video signal waveform synoptic diagram is seen accompanying drawing 1, and " T " among Fig. 1 represents the duration of each pixel level value.

The signal that pattern is approximate, such as 1024 * 768@75Hz and 1280 * 768@75Hz etc., though their HPER, VPER, VLINE are identical, HTOTAL is widely different, and the T value also differs greatly.If these phase plesiotypes of identification of digital plane display mistake will adopt wrong HTOTAL value control A/D to produce wrong sampling clock frequency, can not guarantee like this each pixel level value is correctly sampled, cause display image fuzzy.And because HPER, VPER, VLINE are identical, be to search correct HTOTAL to the identification core of pattern approximate signal.The present invention approaches calculating one by one by employing and the optimum phase quality relatively waits method, therefrom calculates the best (correct) HTOTAL value.

The automatic identifying of pattern of the present invention is as follows: at first according to HTOTAL in each approximate mode and horizontal resolution HRES, approach the best HTOTAL value of calculating various approximate modes one by one, control the A/D sampled signal with these HTOTAL values then, and calculate the display quality value of these approximate modes.The display effect of the size reflection screen picture of display quality value, the display effect of the big more representative screen picture of value is good more.If certain pattern in the mode standard table is the match pattern of input signal, that is through approaching the best HTOTAL value of this pattern that obtains after the calculating one by one, can correctly reflect the variation of input analog video signal T value, assurance is correctly sampled to each pixel level value, and the value of display quality is then big than the value under other non-match pattern in each approximate mode.So, we just can compare the display quality value of various approximate modes, and the pairing HTOTAL value of display quality maximal value can make the display quality of screen picture best, and the pattern of determining according to this HTOTAL value must be the correct pattern of input signal.

So, although the HPER of the signal of various approximate modes, VPER, VLINE parameter may be identical in the mode standard table, by this automatically identifying can find correct HTOTAL, thereby provide foundation for correct these patterns of differentiating.

Concrete, referring to Fig. 2, the present embodiment step is: (describing with the C language format)

Adopt the pattern of conventional method search criterion pattern list identification signal;

If (having approximate display mode)

{

Search and the immediate approximate mode of input signal;

According to HTOTAL in each pattern and horizontal resolution, approach the best HTOTAL value of each pattern of calculating one by one;

Calculate the display quality value of different HTOTAL values respectively;

Selecting the HTOTAL of display quality maximal value correspondence is final HTOTAL value;

Pattern according to the value search criterion pattern list identification signal of final HTOTAL;

Shows signal; Else { shows signal; }

As an embodiment more specifically, at first obtain the vertical resolution of input signal with conventional mode identification method, vertical resolution equals 768 in this example, knownly has 1024 * 768 and 1280 * 768 two kinds of approximate modes under this vertical resolution, so:

1) with conventional mode identification method search criterion pattern list, equal 1024 in horizontal resolution, vertical resolution equal to look in all patterns of 768 one with the immediate pattern of input signal, equal 1280 in horizontal resolution then, vertical resolution equal to look for again in all patterns of 768 one with the immediate pattern of input signal;

2) approach calculating best HTOTAL value separately one by one according to the value (1024 or 1280) of HTOTAL in two patterns and horizontal resolution;

3) on the basis of two best HTOTAL values, calculate the display quality value;

4) get that to make the display quality value be that big HTOTAL value is final HTOTAL value;

5) in the final pairing mode subset of HTOTAL value, look for one near the pattern of input signal.

This pattern is exactly the correct pattern of input analog video signal.

In the automatic identifying of above-mentioned pattern, the definition that approaches calculating and display quality one by one of HTOTAL value is the routine techniques in the digital plane display circuit, in existing digital plane display complete machine Control Software, concrete implementation method is arranged all, therefore the present invention can not use because of the circuit arrangement that adopts different company's master chip, can be implemented at arbitrary digital plane display circuit platform.

Below, the QMB1.2 freeware environment that provides with U.S. PIXELWORKS company is the definition that approaches calculating and display quality one by one that example is described the HTOTAL value.Include the definition that approaches calculating and display quality one by one of HTOTAL value among the QMB1.2, its implementation does not have singularity, can be transplanted to arbitrary digital plane display circuit platform.

QMB1.2 can go up operation at the PW13x series integrated circuit (comprising PW130, PW130A, PW131, PW131A, PW133, PW135 etc.) of PIXELWORKS company exploitation, IC interior is integrated, and the digital plane monitor signal is handled circuit such as necessary CPU, A/D transducer and display format transducer, simulation R, G, the B signal of PC display adapter output can be shown on digital plane screen (as liquid crystal, plasma etc.) after treatment.Include the definition that approaches calculating and display quality one by one of HTOTAL value among the QMB1.2, its implementation does not have singularity, can be transplanted to arbitrary digital plane display circuit platform.Approaching one by one of HTOTAL value is calculated as follows:

The HTOTAL value of correspondence in the WHTOTAL=mode standard table;

N=0; AAA: according to the WHTOTAL value related register is set, changes the sample frequency of AD;

Time-delay;

From the G mouth register of PW13x, read HBI (Horizontal BlankingInterval) value;

WHES＝WHTOTAL-HBI；

IF (the horizontal resolution HES that WHES is corresponding with the mode standard table equates or N equals 3)

Jump to BBB;

}

Value after WHTOTAL=(WHTOTAL * HES ÷ WHES+0.5) rounds;

N＝N+1；

Jump to AAA;

BBB:WHTOTAL approaches the value that obtains after the calculating one by one;

Display quality is defined as follows:

N＝0；

WMAXQ＝0；MAXQ＝0；

WMINQ＝0xFFFFFFFFL；MINQ＝0xFFFFFFFFL；

CCC: the phase value that the AD sampling is set according to the value of N;

Time-delay;

From the G mouth phase place quality register of PW13x, read phase place quality value DW;

IF(DW＞MAXQ){

MAXQ＝DW；

}

IF(DW＜MINQ){

MINQ＝DW；

}

DWQ＝MAXQ+MINQ；

IF(DWQ＞WMAXQ){

WMAXQ＝DWQ；

}

IF(DWQ＜WMINQ){

WMINQ＝DWQ；

}

IF (N equals 32)

BESTQ＝WMAXQ-WMINQ；

Jump to DDD;

}

N＝N+1；

Jump to CCC; DDD:BESTQ is exactly the best image quality value.

Claims (2)

1, analog video signal pattern automatic identifying method is characterized in that, calculates the display quality under each approximate mode, chooses the highest pattern of display quality as correct display mode, may further comprise the steps:

1) search criterion pattern list, if there is no approximate mode then shows, if also there is approximate mode, then enters step 2);

2), approach the best HTOTAL value of each pattern of calculating one by one according to HTOTAL in each pattern and horizontal resolution;

3) difference calculation procedure 2) the display quality value of the best HTOTAL value of each pattern;

4) selecting the HTOTAL of display quality maximal value correspondence is final HTOTAL value;

5) determine correct display mode according to the value search criterion pattern list of final HTOTAL.

2, analog video signal pattern automatic identifying method as claimed in claim 1 is characterized in that, controls the A/D sampled signal with the pattern that best HTOTAL value is determined.

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