A multi-channel video matrix switching system based on FPGA

Abstract

The invention discloses a multi-channel video matrix switching system based on FPGA, which belongs to the technical field of audio and video switching, and specifically comprises: receiving multi-channel audio and video stream input signals through a GT interface and decoding them to obtain n-channel video stream data and n-channel audio stream data; obtaining and parsing the audio and video input signal switching instruction to obtain a target video signal and a target audio signal, determining an input signal group according to the target video signal and the target audio signal, and switching the multi-channel input signals in the input signal group to the same interface; packaging the multi-channel input signals in any input signal group and sending them to the corresponding interface. The invention realizes the simultaneous processing of the switching of multi-channel high-definition audio and video streams under limited hardware resources, and ensures that there is no delay interference between signals and controls the delay of picture switching within one scanning line, thereby bringing a better user experience.

Description

Technical Field

[0001] The invention relates to the technical field of audio and video switching, and in particular to a multi-channel video matrix switching system based on FPGA. Background Art

[0002] Video matrix refers to an electronic system that can output m-channel video signals to n-channel display devices arbitrarily through array switching. It is generally used in various monitoring occasions, such as video conferencing, security monitoring, distance education, and technology courts. The video matrix switching products currently on the market mainly rely on traditional analog matrix switchers or digital matrix switchers. These products achieve video signal switching through hardware circuits or software algorithms, but their structures are complex, their functions are single, and they are difficult to meet the real-time and bandwidth requirements of high-definition video processing.

[0003] Specifically, analog matrix switchers use analog circuits to switch video signals, but due to the limitations of analog circuits themselves, their bandwidth and resolution are low, and they cannot achieve the transmission and processing of high-definition video signals. At the same time, the switching speed of analog matrix switchers is slow and cannot meet the application scenarios with high real-time requirements. Although digital matrix switchers can achieve the transmission and processing of high-definition video signals, they usually use general-purpose processors or dedicated video processing chips as core processors. These processors often have performance bottlenecks when processing multiple high-definition video signals, and cannot achieve efficient video switching and processing. In addition, digital matrix switchers are expensive and have poor scalability, making it difficult to meet the needs of large-scale applications. Summary of the invention

[0004] The purpose of the present invention is to provide a multi-channel video matrix switching system based on FPGA to solve the following technical problems:

[0005] Specifically, analog matrix switchers use analog circuits to switch video signals, but due to the limitations of analog circuits themselves, their bandwidth and resolution are low, and they cannot achieve the transmission and processing of high-definition video signals. At the same time, the switching speed of analog matrix switchers is slow and cannot meet the application scenarios with high real-time requirements. Although digital matrix switchers can achieve the transmission and processing of high-definition video signals, they usually use general-purpose processors or dedicated video processing chips as core processors. These processors often have performance bottlenecks when processing multiple high-definition video signals, and cannot achieve efficient video switching and processing. In addition, digital matrix switchers are expensive and have poor scalability, making it difficult to meet the needs of large-scale applications.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A multi-channel video matrix switching system based on FPGA, comprising:

[0008] The data acquisition module is used to receive and decode multiple audio and video stream input signals through the GT interface to obtain n-channel video stream data and n-channel audio stream data;

[0009] A data switching module is used to obtain and parse the audio and video input signal switching instruction to obtain a target video signal and a target audio signal, determine an input signal group according to the target video signal and the target audio signal, and switch multiple input signals in the input signal group to the same interface;

[0010] Video generation module: used to package multiple input signals in any input signal group and send them to the corresponding interface.

[0011] As a further solution of the present invention: it also includes a video processing module, which is used to obtain separated n-channel video data and n-channel audio data and input them into corresponding n video matrix modules and n audio matrix modules respectively, and determine the output signal of each video matrix module and audio matrix module according to the target video signal and the target audio signal.

[0012] As a further solution of the present invention: the video matrix module and the audio matrix module both adopt a balanced pipeline structure, and the balanced pipeline structure is composed of a number of two-to-one selectors connected in series, and the number of two-to-one selectors in all video matrix modules and audio matrix modules is the same.

[0013] As a further solution of the present invention: all video matrix modules and audio matrix modules use a unified clock to select and process data.

[0014] As a further solution of the present invention: the GT interface includes two channels of audio and video signals, and the GT interface is connected to two video matrix modules and two audio matrix modules.

[0015] As a further solution of the present invention: the data switching module also includes obtaining the serdes input of the output video signal and decomposing it to obtain the row and field signals, and judging the field area where the output video signal is currently located according to the field signal; if the field area is in the blanking area, the video is directly switched; if the field area is in the non-blanking area, the row pixels of the output video signal are obtained and a false color picture is generated to complete the video switching.

[0016] As a further solution of the present invention: the data switching module also includes that the audio data will maintain the current PCM value when the switching is not completed.

[0017] As a further solution of the present invention: the video generation module further includes packaging the target audio signal in the blanking area of ​​the target video signal.

[0018] Beneficial effects of the present invention:

[0019] The pure digital processing method adopted by the present invention shows significant advantages in video switching technology, especially in supporting high-resolution video and ensuring high quality of the switching process. Compared with traditional analog matrix switchers and digital matrix switchers, the present invention has several outstanding technical advantages and practical application improvements;

[0020] Support for higher resolution: With the popularity of high-definition video content, traditional analog matrix switchers often have difficulty processing high-resolution video signals due to their technical limitations. In contrast, the pure digital processing method of the present invention ensures that the video quality is maintained during the transmission and switching process, avoids the attenuation and interference problems in analog signal transmission, and realizes the transmission and switching of higher-definition video.

[0021] Signal timing control: In a multi-channel video system, the time delay between different signals needs to be controlled. In the present invention, each audio and video signal is input into the corresponding processing module, and an equalization pipeline structure is set in the processing module. Each processing module processes one video signal or audio signal, and a unified clock is used to select and process data, so as to ensure that the time delay of multiple video and audio channels is the same, avoid the situation where the picture and audio are not synchronized between different sources, and ensure that the time delay between each signal does not affect each other. This feature ensures that even in a complex multi-signal environment, each video signal can maintain its independence and integrity, avoiding the image quality reduction or synchronization problems caused by mutual interference of signals.

[0022] No need to cache video images: Compared with traditional digital matrix switchers, the present invention will maintain the PCM value of the current output audio when the audio data has not been switched, so as to avoid audio howling during the switching process. At the same time, the serdes input of the output video signal is obtained and decomposed to obtain the row and field signals, and the field area where the output video signal is currently located is determined according to the field signal; if the field area is in the blanking area, the video is directly switched; if the field area is in the non-blanking area, the row pixels of the output video signal are obtained and a false color image is generated to complete the video switching, thereby ensuring a smooth transition before and after the video control switching, and there is no need to cache the video image during the switching process, which greatly reduces the demand for hardware resources. Under limited hardware conditions, the system can process more video streams at the same time, thereby improving the system's processing power and efficiency and reducing the overall cost and complexity of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be further described below in conjunction with the accompanying drawings.

[0024] Figure 1 The present invention is a schematic flow chart of a multi-channel video matrix switching system based on FPGA. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] See also Figure 1 As shown, the present invention is a multi-channel video matrix switching system based on FPGA, comprising:

[0027] The data acquisition module is used to receive and decode multiple audio and video stream input signals through the GT interface to obtain n-channel video stream data and n-channel audio stream data;

[0028] A data switching module is used to obtain and parse the audio and video input signal switching instruction to obtain a target video signal and a target audio signal, determine an input signal group according to the target video signal and the target audio signal, and switch multiple input signals in the input signal group to the same interface;

[0029] Video generation module: used to package multiple input signals in any input signal group and send them to the corresponding interface.

[0030] The pure digital processing method adopted by the present invention shows significant advantages in video switching technology, especially in supporting high-resolution video and ensuring high quality of the switching process. Compared with traditional analog matrix switchers and digital matrix switchers, the present invention has several outstanding technical advantages and practical application improvements;

[0031] Support for higher resolution: With the popularity of high-definition video content, traditional analog matrix switchers often have difficulty processing high-resolution video signals due to their technical limitations. In contrast, the pure digital processing method of the present invention ensures that the video quality is maintained during the transmission and switching process, avoids the attenuation and interference problems in analog signal transmission, and realizes the transmission and switching of higher-definition video.

[0032] Signal timing control: In a multi-channel video system, the time delay between different signals needs to be controlled. In the present invention, each audio and video signal is input into the corresponding processing module, and an equalization pipeline structure is set in the processing module. Each processing module processes one video signal or audio signal, and a unified clock is used to select and process data, so as to ensure that the time delay of multiple video and audio channels is the same, avoid the situation where the picture and audio are not synchronized between different sources, and ensure that the time delay between each signal does not affect each other. This feature ensures that even in a complex multi-signal environment, each video signal can maintain its independence and integrity, avoiding the image quality reduction or synchronization problems caused by mutual interference of signals.

[0033] No need to cache video images: Compared with traditional digital matrix switchers, the present invention will maintain the PCM value of the current output audio when the audio data has not been switched, so as to avoid audio howling during the switching process. At the same time, the serdes input of the output video signal is obtained and decomposed to obtain the row and field signals, and the field area where the output video signal is currently located is determined according to the field signal; if the field area is in the blanking area, the video is directly switched; if the field area is in the non-blanking area, the row pixels of the output video signal are obtained and a false color image is generated to complete the video switching, thereby ensuring a smooth transition before and after the video control switching, and there is no need to cache the video image during the switching process, which greatly reduces the demand for hardware resources. Under limited hardware conditions, the system can process more video streams at the same time, thereby improving the system's processing power and efficiency and reducing the overall cost and complexity of the system.

[0034] It is worth noting that in the present invention, n-channel audio and video data streams first enter the FPGA through the GT interface and are transmitted to n video and audio separation modules. The audio separation module can separate audio with different sampling rates and phases from the data stream for mixing or direct output processing. The video separation module can separate two channels of video from the data stream and select one of them according to the instruction to output to the next-level processing module. The separated n-channel video data and n-channel audio data flow into the corresponding n video matrix modules and n audio matrix modules respectively. These matrix modules switch the video and audio data in real time according to external control signals, thereby generating n-channel switched audio data and n-channel switched video data. The video switching module and the audio switching module both adopt a balanced pipeline structure, which is composed of two-to-one selectors in series, so that each channel from the switching module to the output passes through the same level of selectors, and the same clock is used to select and process the data so that each of the n-channel video and audio channels can pass through The system clock cycle is output to the next level module to ensure that the n-channel video and audio delays are the same, avoiding the situation where the picture and sound are not synchronized between different sources. At the same time, during the switching process, the audio data will maintain the current PCM value before the switching is completed. It can be understood that the PCM value of the preset time threshold before the switching is stored and repeated during the switching to avoid the introduction of high-frequency signals due to the large difference in the instantaneous PCM values ​​before and after the switching; the video signal will send a false color value and a video control signal to ensure a smooth transition before and after the video control switching. It can be understood that the false color duration is short, and the average value is obtained according to the row of pixels output when the video is switched before the switching. If the blanking area is being output during the switching, it means that the current image is black, and the video is switched directly. Then, the n-channel switched audio data and the n-channel switched video data are transmitted to the n video and audio packaging modules. These modules are responsible for packaging audio and video data in a specific format. At the same time, the audio signal is embedded in the video control signal, which is compatible with audio of various sampling rate formats while ensuring the synchronization of audio and picture. Finally, the packaged n-channel audio and video data are sent out through n-channel GT interfaces and transmitted to display devices, storage devices or other terminals that need audio and video data. There is no need to cache the video screen. Under limited hardware conditions, more videos can be processed simultaneously, the picture delay is controlled within one line, and the delays between signals do not affect each other.

[0035] In another preferred embodiment of the present invention, it also includes a video processing module for obtaining separated n-channel video data and n-channel audio data and inputting them into corresponding n video matrix modules and n audio matrix modules respectively, and determining the output signal of each video matrix module and audio matrix module according to the target video signal and the target audio signal.

[0036] It can be understood that the essence of multi-channel video matrix switching is an m*n transmission matrix. The n-channel videos described in the present invention represent all video stream data flowing into the FPGA input end. At the same time, the output target video signal is determined according to the task instruction, and the separated n-channel video data is obtained and input into the corresponding n video matrix modules respectively. Each video matrix module allows one target video stream to pass through, thereby obtaining the output signal of each video matrix module and audio matrix module.

[0037] In another preferred embodiment of the present invention, the video matrix module and the audio matrix module both adopt a balanced pipeline structure, and the balanced pipeline structure is composed of a number of two-to-one selectors connected in series, and the number of two-to-one selectors in all video matrix modules and audio matrix modules is the same.

[0038] It can be understood that both the video switching module and the audio switching module adopt a balanced pipeline structure, which is composed of two-to-one selectors in series, so that each path from the switching module to the output passes through the same level of selectors, ensuring that the n-channel video and audio delays are the same, avoiding the occurrence of asynchronous audio and video between different sources.

[0039] In another preferred embodiment of the present invention, all video matrix modules and audio matrix modules use a unified clock to select and process data.

[0040] It can be understood that the same clock is used to select and process data at the same time so that each of the n video and audio channels can pass through The system clock cycle is output to the next level module to ensure that the n-channel video and audio delays are the same, avoiding the situation where the picture and audio are out of sync between different sources.

[0041] In another preferred embodiment of the present invention, the GT interface includes two channels of audio and video signals, and the GT interface is respectively connected to two video matrix modules and two audio matrix modules.

[0042] It can be understood that each GT interface is used to transmit two channels of audio and video data, and after each channel of audio and video data is separated, it corresponds to an audio matrix module and a video matrix module respectively. Each matrix module selects one of the channels to output to the next level processing module according to the task instructions.

[0043] In another preferred embodiment of the present invention, the data switching module also includes obtaining the serdes input of the output video signal and decomposing it to obtain the row and field signals, and judging the field area in which the output video signal is currently located; if the field area is in the blanking area, the video is directly switched; if the field area is in the non-blanking area, the row pixels of the output video signal are obtained and a false color picture is generated to complete the video switching.

[0044] By obtaining the row and field signals of the output video signal and decomposing them through the serdes input, it is possible to accurately determine which field area the current output video signal is in. By determining the field area, video switching can be performed in non-image-sensitive areas, which can reduce interference with the visual experience, especially when switching in the blanking area. Since the image is not displayed during the electron beam moving from the right end to the left end, the switching will not have any visible effect on the screen, thereby maintaining the clarity and smoothness of the image. Video switching in the blanking area makes the switching process staggered with the active scanning of the image, reducing interference with the normal scanning of the video signal and improving the continuity and stability of the video; video switching in the non-blanking area may cause damage to the image, such as pixel loss or dislocation, resulting in a brief blur or flickering of the image. Therefore, by obtaining the row pixels of the output video signal and generating a false color image, the video switching can be smoothly transitioned without affecting the user's viewing experience, thereby further improving the visual effect.

[0045] In another preferred embodiment of the present invention, the data switching module further includes that the audio data will maintain the current PCM value when the switching has not been completed.

[0046] It is understandable that the PCM values ​​for a period of time before the switch are stored and played again when switching, so as to avoid the introduction of high-frequency signals due to the large difference in the instantaneous PCM values ​​before and after the switch, and to avoid the audio howling problem during the switching process.

[0047] In another preferred embodiment of the present invention, the video generation module further includes packaging the target audio signal in a blanking area of ​​the target video signal.

[0048] It can be understood that by embedding the audio signal into the blanking area of ​​the video signal, the audio data can be transmitted without affecting the transmission of the video signal, allowing the audio data to be transmitted together with the video signal without occupying additional bandwidth, thereby achieving efficient data transmission.

[0049] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A multi-channel video matrix switching system based on FPGA, characterized in that: include: The data acquisition module is used to receive and decode multiple audio and video stream input signals through the GT interface to obtain n-channel video stream data and n-channel audio stream data; A video processing module, used to obtain separated n-channel video stream data and n-channel audio stream data and input them into corresponding n video matrix modules and n audio matrix modules respectively, and determine the output signal of each video matrix module and audio matrix module according to the target video signal and the target audio signal; the video matrix module and the audio matrix module both adopt a balanced pipeline structure, and the balanced pipeline structure is composed of a plurality of two-choice selectors connected in series, the number of two-choice selectors in all video matrix modules and audio matrix modules is the same, and all video matrix modules and audio matrix modules use a unified clock to select and process data; A data switching module is used to obtain and parse the audio and video input signal switching instruction to obtain a target video signal and a target audio signal, determine an input signal group according to the target video signal and the target audio signal, and switch multiple input signals in the input signal group to the same interface; Get the serdes input of the output video signal and decompose it to get the line and field signals, and determine the field area where the output video signal is currently located according to the field signal; if the field area is in the blanking area, directly perform video switching; if the field area is in the non-blanking area, get the line pixels of the output video signal and generate a false color picture to complete the video switching; the audio data will maintain the current PCM value when the switching is not completed; Video generation module: used to package multiple input signals in any input signal group and send them to the corresponding interface.

2. The FPGA-based multi-channel video matrix switching system according to claim 1, characterized in that: The GT interface includes two channels of audio and video signals, and the GT interface is connected to two video matrix modules and two audio matrix modules respectively.

3. The FPGA-based multi-channel video matrix switching system according to claim 1, characterized in that: The video generation module also includes packaging the target audio signal in the blanking area of ​​the target video signal.

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