CN102158634B - Vertical synchronization signal separation device and method - Google Patents

Abstract

The invention discloses a vertical synchronizing signal separating device and a method. The vertical synchronizing signal separating apparatus includes: a parameter detecting unit, a threshold generating unit and a vertical synchronizing signal generating unit. The parameter detection unit measures a composite synchronization signal to obtain maximum and next largest positive pulse widths and maximum and next largest negative pulse widths. The threshold generation unit outputs a positive pulse threshold according to the maximum and the next largest positive pulse widths, and outputs a negative pulse threshold according to the maximum and the next largest negative pulse widths. The vertical synchronization signal generation unit compares the composite synchronization signal using the positive pulse threshold and the negative pulse threshold, thereby outputting a vertical synchronization signal. Therefore, the device can accurately separate the vertical synchronous signal from the composite synchronous signal of different standards, and can improve the compatibility of the vertical synchronous signal.

Description

Vertical synchronization signal separation device and method

technical field

The invention relates to the technical field of composite sync signal (Composite sync signal) processing, in particular to a device and method for separating a vertical sync signal (Vertical sync signal) from a composite sync signal.

Background technique

When transmitting high-definition television (HDTV), Y (brightness signal), UV (double density signal) or R (red), G (green), B (blue) color coding methods are often used for image transmission . That is to say, high-definition television (HDTV) often converts the image into a luminance signal (Luminance signal, referred to as Y) and two density signals (Chrominance signal, referred to as U, V), or converts it into a red signal R, a green signal Signal G and blue signal B. Wherein, the composite sync signal (Composite sync signal) will be mixed in the brightness signal Y or the green signal G.

According to different specifications and standards, the composite synchronous signal is composed of horizontal synchronization signal (horizontal synchronization signal), vertical synchronization signal (vertical synchronization signal), blank signal (blank signal) or other signals, such as video signal, audio signal wait. The image receiver (Rx) performs signal separation after receiving the composite synchronous signal, thereby obtaining horizontal and vertical synchronous signals from it, so that the display can perform image scanning action according to the horizontal synchronous signal and vertical synchronous signal.

There are many technical methods to separate the vertical sync signal from the composite sync signal. However, since the timing characteristics of each video standard are different, many separation techniques can only be applied to specific standards, but cannot flexibly separate the vertical sync signal from all standard and non-standard composite sync signals. In addition, some technologies can receive and compare the reference signal embedded in the synchronization signal in advance, so as to distinguish whether the synchronization signal is in a known standard format. However, these techniques cannot reliably separate the vertical sync signal when the sync signal is in a non-standard format. Therefore, many manufacturers hope to develop a separation technology that can be applied to all standard and non-standard composite synchronous signals, so as to reliably separate the vertical synchronous signal required by the image.

Contents of the invention

The invention provides a vertical synchronous signal separation device, which can support all high and low frequencies, different polarities, standard and non-standard composite synchronous signals, so as to correctly separate the vertical synchronous signals.

On the other hand, the present invention provides a vertical synchronization signal separation method, which can support all high and low frequency, different polarity, standard and non-standard composite synchronization signals, so as to correctly separate the vertical synchronization signals.

The invention proposes a vertical synchronization signal separation device, which includes a parameter detection unit, a threshold generation unit and a vertical synchronization signal generation unit. The parameter detection unit receives and measures the composite synchronous signal, so as to obtain parameters such as the maximum positive pulse width, the second largest positive pulse width, the largest negative pulse width, and the second largest negative pulse width of the composite synchronous signal. The threshold generation unit is connected with the parameter detection unit, which outputs the positive pulse threshold according to the largest positive pulse width and the next largest positive pulse width, and outputs the negative pulse threshold according to the largest negative pulse width and the second largest negative pulse width. The vertical synchronous signal generating unit compares the composite synchronous signal according to the positive pulse threshold and the negative pulse threshold, so as to output the vertical synchronous signal.

In an embodiment of the present invention, the above positive pulse threshold should be between the maximum positive pulse width and the second largest positive pulse width, and the negative pulse threshold should be between the largest negative pulse width and the second largest negative pulse width.

In an embodiment of the present invention, when the above-mentioned vertical synchronous signal generation unit detects the positive edge of the composite synchronous signal, the positive edge counter is reset to zero and starts counting, and when the counting time reaches the positive pulse threshold, the vertical synchronous signal The generating unit enables the vertical synchronization signal. In contrast, when the vertical synchronous signal generation unit senses the negative edge of the composite synchronous signal, the positive edge counter resets to zero and starts counting, and when the count time reaches the negative pulse threshold, the vertical synchronous signal generation unit sends the vertical synchronous signal disabled.

In an embodiment of the present invention, when the maximum negative pulse width is greater than the maximum positive pulse width, the maximum positive pulse width is equal to the second largest positive pulse width, and the second largest positive pulse width is smaller than the second largest negative pulse width, the negative pulse threshold should be greater than and close to The next largest negative pulse width.

From another point of view, the present invention proposes a vertical synchronous signal separation method, including the following steps: receiving and measuring the composite synchronous signal, thereby obtaining the maximum positive pulse width, the next largest positive pulse width, the maximum negative pulse width and The next largest negative pulse width. Then, a positive pulse threshold is output according to the maximum positive pulse width and the second largest positive pulse width, and a negative pulse threshold is output according to the largest negative pulse width and the second largest negative pulse width. And, compare the composite synchronous signal according to the positive pulse threshold and the negative pulse threshold, so as to output the vertical synchronous signal.

Based on the above, the embodiment of the present invention utilizes the width of the positive pulse and the negative pulse of the composite sync signal to set the thresholds of the positive pulse and the negative pulse respectively, and uses these thresholds to distinguish the vertical sync signal from the composite sync signal. Therefore, the vertical synchronization signal separation device of this embodiment can support all currently known standard and non-standard composite synchronization signals of different frequencies and different polarities, and can correctly separate the vertical synchronization signal, thereby improving its application range and performance .

Description of drawings

FIG. 1 is a schematic structural diagram of an image signal processing system including a vertical synchronization signal separation device according to an embodiment of the present invention.

FIG. 2 is a schematic structural diagram of a device for separating a vertical synchronization signal according to an embodiment of the present invention.

FIG. 3 is a flowchart of a vertical synchronization signal separation method according to the first embodiment of the present invention.

FIG. 4 is a waveform diagram of a composite sync signal and a vertical sync signal of the 720p25 standard.

Figure 5 is a waveform diagram of the composite sync signal and vertical sync signal of the SERR 0.5H standard.

FIG. 6 is a waveform diagram of a composite sync signal and a vertical sync signal conforming to the H+V standard of the first embodiment.

FIG. 7 is a flowchart of a vertical synchronization signal separation method according to a second embodiment of the present invention.

FIG. 8 is a waveform diagram of a composite sync signal and a vertical sync signal conforming to the H+V standard of the second embodiment.

Explanation of symbols in the attached drawings

100: Image signal processing system

102: Image bearing signal

110: Signal limiter

112, 412, 512, 612, 812: Composite sync signal

120: Vertical synchronization signal separation device

122, 422, 522, 622, 822: vertical sync signal

130: Pulse generator

140: display device

210: Parameter detection unit

220: Threshold generating unit

230: vertical synchronization signal generation unit

A～H, A’～H’: time point

MPPW: maximum positive pulse width

SPPW: Second Largest Positive Pulse Width

MNPW: maximum negative pulse width

SNPW: Second Largest Negative Pulse Width

S310～S720: steps

PE: positive pulse

T _UP : positive pulse threshold

T _DN : Negative Pulse Threshold

I _DIS : Disabled interval of ideal vertical sync signal

I _DIS ': Disabled interval of the actual vertical sync signal

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and examples. In addition, wherever possible, components/members/symbols with the same reference numbers are used in the drawings and embodiments to represent the same or similar parts.

Please refer to FIG. 1 . FIG. 1 is a schematic structural diagram of an image signal processing system including a vertical synchronization signal separation device 120 according to an embodiment of the present invention. The image signal processing system 100 includes a signal limiter 110 , a vertical synchronization signal separation device 120 , a pulse generator 130 and a display device 140 . In this embodiment, the signal limiter 110 receives the image-bearing signal 102 (in this embodiment, the luminance signal (Luminance signal) Y in YUV image conversion format is used as the implementation mode, but not limited thereto), and utilizes a voltage threshold from A composite sync signal (Composite sync signal) 112 is limited and separated from the image bearing signal 102 .

Next, the vertical sync signal separating device 120 separates the vertical sync signal 122 from the composite sync signal 112 , and outputs the vertical sync signal 122 to the pulse generator 130 . Therefore, those skilled in the art know that the pulse generator 130 then performs an image scanning operation according to the vertical synchronous signal 122 to display the signal on the display device 140 . In addition, those who apply this embodiment should be able to understand based on their design requirements that when the image-bearing signal 102 can use other methods or can directly separate the composite synchronization signal 112 to input to the vertical synchronization signal separation device 120, the image signal processing system 100 does not need to have a signal limiter 110 .

Therefore, the key point of the embodiment of the present invention is that the vertical synchronous signal separation device 120 can support all currently known standard and non-standard composite synchronous signals 112 of different frequencies and different polarities, and can correctly separate the vertical synchronous signal 122 , so as to improve the application range and performance of the vertical synchronization signal separation device 120 . Therefore, the functional structure and operation mode of the vertical synchronization signal separating device 120 will be described in detail below, and FIG. 4 is taken as an example for illustration.

Fig. 2 is a schematic structural diagram of a vertical synchronous signal separation device 120 according to an embodiment of the invention, Fig. 3 is a flow chart of a vertical synchronous signal separation method according to a first embodiment of the present invention, and Fig. 4 is a composite synchronous signal 412 and vertical synchronous Signal 422 waveform diagram. Wherein, the vertical synchronization signal separation device 120 includes a parameter detection unit 210 , a threshold generation unit 220 and a vertical synchronization signal generation unit 230 . In this embodiment, the threshold generation unit 220 is coupled to the parameter detection unit 210 and the vertical synchronization signal generation unit 230 respectively, and the vertical synchronization signal generation unit 230 is also coupled to the parameter detection unit 210 .

Please refer to FIG. 2 and FIG. 3 together with FIG. 4. First, in step S310, the parameter detection unit 210 receives the composite synchronous signal 412, and detects each positive pulse (positive pulse) and negative pulse (positive pulse) in the composite synchronous signal 412 ( negative pulse), so as to obtain the relevant parameters of the composite sync signal 412. In this embodiment, the duration of each pulse is referred to as a pulse width (pulse width), so as to simplify the description. FIG. 4 is a waveform diagram of the composite sync signal 112 and the vertical sync signal 122 , where the composite sync signal is labeled 412 and the vertical sync signal is labeled 422 . Moreover, the parameter detecting unit 210 stores the positive pulse width and negative pulse width with the longest duration, the positive pulse width and the negative pulse width with the second longest duration into the maximum positive pulse width MPPW, the maximum negative pulse width MNPW, the second The largest positive pulse width SPPW and the next largest negative pulse width SNPW and other parameters (as shown in FIG. 4 ), and transmit these parameters to the threshold generation unit 220 .

In step S320, the threshold generation unit 220 generates the positive pulse threshold T _UP according to the maximum positive pulse width MPPW and the second largest positive pulse width SPPW, and generates the negative pulse threshold T DN according to the largest negative pulse width MNPW and the second largest negative pulse width _SNPW . In this embodiment, those skilled in the art should be able to adjust the selected positive pulse threshold T _UP and positive pulse threshold T _DN according to the design requirements and the specification standard of the composite synchronous signal 412, so that the positive pulse threshold T _UP The value is between the maximum positive pulse width MPPW and the second largest positive pulse width SPPW, and the value of the negative pulse threshold T _DN is between the maximum negative pulse width MNPW and the second largest negative pulse width SNPW. In FIG. 4, the value of the positive pulse threshold T _UP will be between 53us and 32us.

Next, the vertical synchronous signal generation unit 230 receives and compares the composite synchronous signal 412 according to the positive pulse threshold T _UP and the negative pulse threshold T _DN , so as to output the vertical synchronous signal 422 . Specifically, in this embodiment, the vertical synchronization signal generating unit 230 includes a positive edge counter PC and a negative edge counter NC (not shown). In step S320, when the vertical synchronous signal generation unit 230 detects the positive edge of the composite synchronous signal 412, in other words, when the positive edge counter PC in the vertical synchronous signal generation unit 230 is triggered by the positive edge of the composite synchronous signal 412 ( As shown in time points A, B, C, and D of FIG. 4 ), it enters step S340, and the positive edge counter PC resets to zero and starts counting. And, when the counting time of the positive edge counter PC reaches the positive pulse threshold TUP (such as time points A' and D'), step S350 enters step S360, and the vertical synchronous signal generating unit 230 enables the vertical synchronous signal 422 , and in this embodiment, the vertical synchronous signal generating unit 230 sets the vertical synchronous signal 422 to logic 1 to make it an enabled state, but the present invention is not limited thereto, in other words, other embodiments It is also possible to set the vertical sync signal 422 to logic 0 to enable it.

On the other hand, when the positive edge counter PC receives the negative edge of the composite synchronous signal 412 before its counting time reaches the positive pulse threshold T _UP , in other words, the positive edge counter PC and the vertical synchronous signal generating unit 230 When the negative edge counter NC is triggered by the negative edge of the composite synchronous signal 412 (such as time points B' and C' in Figure 4), it returns from step S350 to step S330 so that the positive edge counter PC stops counting, and enters through step S370 In step S380, the negative edge counter NC is reset to zero and starts counting (such as time points E, E, G to H). When the counting time of the negative edge counter reaches the negative pulse threshold T _DN (such as time points F' and G'), step S390 enters step S395, and the vertical synchronous signal generation unit 230 disables the vertical synchronous signal 422. In this implementation In an example, the vertical synchronous signal generating unit 230 sets the vertical synchronous signal 422 to logic 0 to make it in a disabled state, but the invention is not limited thereto. In other words, other embodiments may also set the vertical synchronization signal 422 to logic 1 to disable it.

Similarly, when the negative edge counter NC receives the positive edge of the composite sync signal 412 before the count time reaches the negative pulse threshold T _DN , in other words, the positive edge counter PC and the negative edge counter PC in the vertical sync signal generating unit 230 When the counter NC is triggered by the positive edge of the composite synchronous signal 412 (such as time points E' and H' in Figure 4), it returns to step S330 from step S390 to stop counting of the negative edge counter NC, and enters step S340 to make the positive edge The counter PC is reset to zero and starts counting again.

Based on the above, the vertical synchronous signal separation device 120 uses the relevant parameters of the input composite synchronous signal 412 to determine and separate the vertical synchronous signal 422 , so it can support multiple standards and composite synchronous signals of different frequencies. Since the positive pulse and negative pulse judging methods of the vertical synchronous signal separation device 120 of this embodiment are not different due to different polarities, in other words, the high and low potentials of the positive pulse and negative pulse do not affect the vertical synchronous signal after transposition Therefore, the embodiment of the present invention can also support composite synchronization signals of different polarities (including composite synchronization signals of 720p23, 720p24, 720p25, SERR, SERR 0.5H, HEORV, and H+V standards).

Furthermore, the positive edge counter PC and the negative edge counter NC in the above-mentioned vertical synchronization signal generating unit 230 are different counters in this embodiment, and in other embodiments, the positive edge counter PC and the negative edge counter NC can also be the same counter. When the counter is triggered by the positive edge and the negative edge of the composite synchronous signal 412 , it will reset to zero and start counting. When triggered by the positive edge of the composite synchronous signal 412 , the counter determines whether its counting time reaches the positive pulse threshold T _UP , thereby enabling the vertical synchronous signal. In contrast, when the counter is triggered by the negative edge of the composite synchronous signal 412 , the counter determines whether its counting time reaches the negative pulse threshold T _DN , thereby disabling the vertical synchronous signal. Other actions and processes of the counter are similar to the above-mentioned positive edge counter PC and negative edge counter NC, so they will not be repeated here.

On the other hand, in this embodiment, the parameter detection unit 210 will continuously measure and update the relevant parameters in the composite synchronous signal 412, so that the threshold generation unit 220 can automatically and dynamically change the positive pulse threshold T _UP and the negative pulse threshold T _DN . Therefore, the vertical synchronous signal generating unit 230 can continuously output accurate vertical synchronous signals.

Another standard composite synchronization signal is proposed here to support the embodiment of the present invention, as shown in FIG. 5 , which is a waveform diagram of a composite synchronization signal 512 and a vertical synchronization signal 522 of the SERR 0.5H standard. Since the judging method and actions of this embodiment are the same as those of the first embodiment above, details will not be repeated here.

However, as shown in FIG. 6 , FIG. 6 is a waveform diagram of a composite sync signal 612 and a vertical sync signal 622 conforming to the H+V standard of the first embodiment. Wherein, the dotted line part of the vertical synchronous signal 622 is the waveform under the ideal state, and the solid line part is the vertical synchronous signal 622 waveform after actually using the first embodiment for actual judgment, and the maximum positive pulse width MPPW and The next largest positive pulse width SPPW is 53us. Since the composite synchronous signal 612 of the H+V standard only has a positive pulse PE at the end of the disabling interval _IDIS of the ideal vertical synchronizing signal 622, and there is no pulse in other regions of the disabling interval _IDIS , and FIG. 2 The threshold generation unit 220 can randomly or other calculation methods obtain the negative pulse threshold T _DN between the values of the maximum negative pulse width MNPW and the next largest negative pulse width SNPW, so that the disabled interval I _DIS ' of the actual vertical synchronization signal 622 is too short, Thus causing the frequency to be inaccurate.

In view of this, a second embodiment in line with the spirit of the present invention is proposed here by utilizing the functional architecture in FIG. 2 and the action flow in FIG. 7, and cooperates with the waveform diagram in FIG. The sync signal 812 separates the vertical sync signal 822 from the problem. FIG. 7 is a flow chart of a vertical sync signal separation method according to the second embodiment of the invention, and FIG. 8 is a waveform diagram of a composite sync signal 812 and a vertical sync signal 822 conforming to the H+V standard of the second embodiment.

Please refer to FIG. 2 , FIG. 7 and FIG. 8 at the same time. The difference between this embodiment and the above-mentioned first embodiment is that after the parameter detection unit 210 receives and measures the relevant parameters of the composite synchronous signal 112 in step S310, this embodiment The threshold generating unit 220 of the embodiment judges the characteristics of the H+V standard composite synchronous signal 112 in step S710, that is, judges that the maximum negative pulse width MNPW is greater than the maximum positive pulse width MPPW, and the maximum positive pulse width MPPW is equal to the next largest positive pulse width SPPW, And whether the condition that the second largest positive pulse width SPPW is greater than the second largest negative pulse width SNPW (ie MNPW>MPPW=SPPW>SNPW) holds true.

且T_DN＞SNPW)。本领域普通技术人员可以根据H+V标准复合同步信号和垂直同步信号特性选取合适的负脉冲阈值T_DN。另外，步骤S720中，正脉冲阈值T_UP的产生及判断方式则与第一实施例相同。相对地，当步骤S710的条件不成立时，代表此复合同步信号812应为其它标准，因此可根据第一实施例的动作方式继续执行。因此，图8所示的同步垂直信号822便不会发生其禁能区间I_DIS’过短而造成的频率错误等问题。When the condition of step S710 is established, it means that the composite synchronous signal 812 should be H+V standard, so it enters step S720, and the negative pulse threshold T _DN generated by the threshold generation unit 220 should be close to the next largest negative pulse width SNPW, but less than The next largest negative pulse width SNPW is slightly larger (ie

and T _DN >SNPW). Those skilled in the art can select an appropriate negative pulse threshold T _DN according to the characteristics of the H+V standard composite sync signal and the vertical sync signal. In addition, in step S720 , the generation and determination method of the positive pulse threshold T _UP is the same as that of the first embodiment. Relatively, when the condition of step S710 is not satisfied, it means that the composite sync signal 812 should be of other standards, and thus the operation can be continued according to the first embodiment. Therefore, the synchronous vertical signal 822 shown in FIG. 8 does not have problems such as frequency error caused by the too short disabling interval _IDIS ′.

In summary, the embodiments of the present invention use the pulse widths of the positive pulse and the negative pulse of the composite sync signal to set the thresholds of the positive pulse and the negative pulse, and use these thresholds to identify the vertical sync signal from the composite sync signal. Therefore, the vertical synchronous signal separation device 120 of this embodiment can support composite synchronous signals of all known standards and non-standards, different frequencies and different polarities, and can correctly separate the vertical synchronous signals, thereby improving its application range and performance. Of course, if the method of the first embodiment of the present invention is used to process the composite synchronous signal of the H+V standard, the separation of the vertical synchronous signal can also be realized, and the above-mentioned technical effect can be achieved. Moreover, in the second embodiment of the present invention, the judging method of the H+V standard composite synchronous signal is further added, so as to solve the problems such as frequency error caused by too short forbidden interval of the vertical synchronous signal.

The preferred embodiments above are used to further describe the purpose, technical solutions and advantages of the present invention in detail. It should be understood that the above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Within the spirit and principles of the present invention, any modifications, equivalent replacements, improvements, etc., should be included within the protection scope of the present invention, and the scope of rights claimed by the present invention should be based on the scope of the application for the invention. Rather than being limited to the above-mentioned embodiments.

Claims (14)

1. A vertical synchronization signal separation device, characterized in that, comprising: a parameter detection unit, receiving and measuring a composite synchronous signal to obtain a maximum positive pulse width, a large positive pulse width, a maximum negative pulse width and a large negative pulse width of the composite synchronous signal; a threshold generation unit, coupled to the parameter detection unit, for outputting a positive pulse threshold according to the maximum positive pulse width and the second largest positive pulse width, and outputting a positive pulse threshold according to the maximum negative pulse width and the second largest negative pulse width pulse width output negative pulse threshold; and A vertical synchronous signal generating unit is used for comparing the composite synchronous signal according to the positive pulse threshold and the negative pulse threshold, so as to output a vertical synchronous signal. 2. The vertical synchronization signal separation device according to claim 1, wherein the positive pulse threshold is located between the maximum positive pulse width and the next largest positive pulse width, and the negative pulse threshold is located between the between the maximum negative pulse width and the next largest negative pulse width. 3. The vertical synchronous signal separation device according to claim 2, wherein the vertical synchronous signal generating unit comprises: A positive edge counter, when detecting the positive edge of the composite synchronous signal, reset to zero and start counting, and when the counting time reaches the positive pulse threshold, the vertical synchronous signal is enabled; the positive edge counter When the negative edge of the composite sync signal is detected before the counting time reaches the positive pulse threshold, stop counting the positive edge counter, reset the negative edge counter to zero and start counting; and A negative edge counter, when detecting the negative edge of the composite synchronous signal, reset to zero and start counting, and when the count time reaches the negative pulse threshold, disable the vertical synchronous signal; the negative edge counter When the positive edge of the composite synchronous signal is detected before the counting time reaches the negative pulse threshold, the negative edge counter stops counting, and the positive edge counter resets to zero and starts counting. 4. The vertical synchronous signal separating device as claimed in claim 2, wherein the vertical synchronous signal generating unit comprises: a counter, and when the positive edge of the composite synchronous signal is detected, the counter is reset to zero and Start counting, and when the counting time reaches the positive pulse threshold, the vertical synchronization signal is enabled, and when the negative edge of the composite synchronization signal is detected, the counter resets to zero and starts counting, and when When the counting time reaches the negative pulse threshold, the vertical synchronization signal is disabled; when the counter detects the negative edge of the composite synchronization signal before the counting time reaches the positive pulse threshold, it stops count the counter, reset it to zero and start counting again; and stop counting the counter, reset it to zero and start counting again. 5. The vertical synchronization signal separation device according to claim 1, wherein when the maximum negative pulse width is greater than the maximum positive pulse width, the maximum positive pulse width is equal to the next largest positive pulse width, and the When the second largest positive pulse width is smaller than the second largest negative pulse width, the negative pulse threshold is set to be slightly larger than and close to the second largest negative pulse width. 6. vertical synchronous signal separation device as claimed in claim 5, is characterized in that, wherein the standard of described composite synchronous signal is 720p25 standard, 720p24 standard, 720p23 standard, SERR, HEOR V, SERR0.5H standard and H+ One of the V standards. 7. The vertical synchronization signal separation device according to claim 1, wherein the parameter detection unit continuously measures and updates the maximum positive pulse width, the next largest positive pulse width, The maximum negative pulse width and the next largest negative pulse width enable the threshold generation unit to dynamically adjust the positive pulse threshold and the negative pulse threshold. 8. A vertical synchronization signal separation method, characterized in that the method comprises: receiving and measuring a composite sync signal to obtain a maximum positive pulse width, a large positive pulse width, a maximum negative pulse width, and a large negative pulse width of the composite sync signal; outputting a positive pulse threshold based on the maximum positive pulse width and the second largest positive pulse width, and outputting a negative pulse threshold based on the largest negative pulse width and the second largest negative pulse width; and The composite synchronous signal is compared according to the positive pulse threshold and the negative pulse threshold, so as to output a vertical synchronous signal. 9. The vertical synchronization signal separation method according to claim 8, wherein the positive pulse threshold is located between the maximum positive pulse width and the next largest positive pulse width, and the negative pulse threshold is located between the between the maximum negative pulse width and the next largest negative pulse width. 10. vertical synchronous signal separation method as claimed in claim 9 is characterized in that, outputting described vertical synchronous signal comprises the following steps: S330, judging whether the positive edge of the composite synchronous signal is sensed, if yes, execute step S340, otherwise execute step S370; S340, the positive edge counter is reset to zero and starts counting; S350, judging whether the counting time of the positive edge counter reaches the positive pulse threshold, if so, execute step S360, otherwise, return to step S330; S360, enable the vertical synchronization signal, and return to step S330; S370, judging whether the negative edge of the composite synchronous signal is sensed, if yes, execute step S380, otherwise, return to step S330; S380, the negative edge counter is reset to zero and starts counting; S390, judging whether the counting time of the negative edge counter reaches the negative pulse threshold, if so, execute step S395, otherwise, return to step S330; S395 disables the vertical synchronization signal, and returns to step S330. 11. vertical synchronous signal separation method as claimed in claim 9 is characterized in that, outputting described vertical synchronous signal comprises the following steps: S330, judging whether the positive edge of the composite synchronous signal is sensed, if yes, execute step S340, otherwise execute step S370; S340, the counter returns to zero and starts counting; S350, judging whether the counting time of the counter reaches the positive pulse threshold, if so, execute step S360, otherwise, return to step S330; S360, enabling the vertical synchronization signal, and returning to step S330; S370, judging whether the negative edge of the composite synchronization signal is sensed, if so, performing step S380, otherwise, returning to step S330; S380, the counter resets to zero and starts counting; S390, judging whether the counting time of the counter reaches the negative pulse threshold, if so, execute step S395, otherwise, return to step S330; S395 disables the vertical synchronization signal, and returns to step S330. 12. vertical synchronization signal separation method as claimed in claim 9 is characterized in that, described method further comprises: When the maximum negative pulse width is greater than the maximum positive pulse width, the maximum positive pulse width is equal to the second largest positive pulse width, and the second largest positive pulse width is smaller than the second largest negative pulse width, set the The negative pulse threshold is slightly greater than and close to the next largest negative pulse width. 13. vertical synchronous signal separation method as claimed in claim 12 is characterized in that, wherein the standard of said composite synchronous signal is 720p25 standard, 720p24 standard, 720p23 standard, SERR, HEOR V, SERR0.5H standard and H+ One of the V standards. 14. The vertical synchronization signal separation method according to claim 9, wherein the method further comprises: continuously measuring and updating the maximum positive pulse width, the second largest positive pulse width, the largest negative pulse width, and the second largest negative pulse width of the composite sync signal to dynamically adjust the positive pulse threshold and the Negative Pulse Threshold.

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