Digital video transmission control system and method based on dual-fiber channel for airborne

Abstract

The application discloses a kind of based on dual optical fiber channel's airborne digital video transmission control system and method, belong to computer communication count field.The method includes collecting original video signal;According to the rule of odd-even row separation, video row data is distributed to odd row and even row buffer;Real-time monitoring buffer write state and maintaining write state parameter, according to field synchronization signal and write state parameter, alternately extract odd row video row data and even row video row data;The video row data extracted is framed respectively, then is sent in parallel by two independent optical fiber channels, and the sending timing of two channels is coordinated, frame alignment and interline alignment are maintained.The application can break through the bandwidth limit of single optical fiber channel, realize the real-time reliable transmission of high-resolution, high-frame-rate airborne digital video.

Description

Technical Field

[0001] This invention relates to the field of computer communication, and specifically to an airborne digital video transmission control system and method based on dual fiber optic channels. Background Technology

[0002] In the field of airborne video transmission, traditional transmission methods are mainly based on dedicated cables. These methods have the following drawbacks: limited transmission distance, making it difficult to meet the needs of long-distance transmission within large platforms; heavy and bulky cables, which contradicts the trend of lightweight development in avionics systems; susceptible to complex electromagnetic environments, which may lead to image quality degradation or transmission errors; and difficulty in bandwidth expansion, making it difficult to carry the raw data stream of ultra-high resolution video.

[0003] Fiber Channel (FC) has become the core transmission medium for airborne high-speed video transmission networks due to its advantages such as high bandwidth, low latency, resistance to electromagnetic interference, and support for long-distance transmission. Based on the FC protocol stack, those skilled in the art have developed application-layer protocols for airborne digital video transmission. By defining the encapsulation format and transmission rules for video data, these protocols can effectively ensure the timing correctness and data integrity of a single video stream from acquisition and framing to transmission.

[0004] However, with the continuous development of video acquisition technology, the raw data rate of a single video stream has approached or even exceeded the available bandwidth limit of existing single-channel fiber optic cables. For example, a typical high-resolution video stream can have a raw data rate exceeding 10Gbps, while the bandwidth of current mainstream airborne fiber optic cables is typically 4Gbps or 8Gbps. If methods such as reducing resolution, lowering frame rate, or using lossy compression are employed to accommodate the single-channel bandwidth, video quality and real-time transmission will be sacrificed, failing to meet the mission system's requirements for high-fidelity, low-latency transmission of raw image information.

[0005] An intuitive solution is to adopt the higher-speed Fibre Channel standard, but this involves a series of complex issues such as system architecture upgrades, development of new optical modules, and compatibility verification. The development cycle is long, the cost is high, and it is difficult to deploy quickly on existing platforms.

[0006] To address the aforementioned issues, the field has begun exploring multi-channel parallel transmission technologies, which involve splitting a single high-bandwidth video stream and transmitting it in parallel through multiple independent fiber optic channels, then reassembling it at the receiving end. Theoretically, this approach can multiply transmission bandwidth, but it faces a series of technical challenges in practical applications: First, how to reasonably split the video stream? Simple packet polling and distribution can disrupt the integrity of video lines, preventing the receiving end from correctly reassembling them; a splitting strategy that maintains the integrity of the video line structure is needed. Second, how to ensure strict timing synchronization of the split data streams at the sending end? If the start times of transmission for multiple channels are inconsistent, or the transmission intervals between lines are mismatched, the receiving end will be unable to recover the correct image line order. Third, how to design a buffer management mechanism to achieve pipelined operation of video acquisition and multi-channel transmission, avoiding data interruption or delay due to buffer conflicts. Finally, how to ensure that the split data streams conform to the Fibre Channel digital video transmission specifications at the protocol level, facilitating reception at the receiving end using a standard protocol stack.

[0007] For the transmission control of dual-channel parallel transmission, some studies have attempted to use frame-level separation, that is, sending odd-numbered frames and even-numbered frames through different channels. However, this method cannot solve the problem of insufficient instantaneous effective bandwidth. Another approach is to divide a frame of image into two parts evenly according to the number of rows, and send them through two separate channels. However, this scheme lacks fine-grained control over the timing of transmission between the two channels, and cannot ensure inter-line synchronization, which can easily lead to row data misalignment or splicing errors during reassembly at the receiving end.

[0008] Therefore, a parallel transmission scheme is needed that can reasonably split the video stream while maintaining the integrity of the video line structure and accurately control the transmission timing of multiple channels. How to implement a video transmission control method and system based on dual fiber optic channels that can maintain the integrity of the line structure and ensure strict synchronization of the two channels has become a pressing technical problem to be solved in this field. Summary of the Invention

[0009] To address the shortcomings of existing technologies, this invention provides an airborne digital video transmission control system and method based on dual fiber optic channels. The aim is to split a high-bandwidth video stream into two independent fiber optic channels for parallel transmission, thereby expanding the transmission bandwidth without upgrading the physical link and ensuring that the two split data streams remain strictly synchronized at the transmitting end, enabling the receiving end to recover the original image without loss.

[0010] To achieve the above objectives, the present invention provides the following technical solution:

[0011] An airborne digital video transmission control method based on dual fiber optic channels includes the following steps:

[0012] S1. Acquire the raw video signal of the image frame, which includes pixel data, field synchronization signal, and line synchronization signal; use the field synchronization signal to identify the start of the image frame;

[0013] S2. Based on the field synchronization signal and the line synchronization signal, capture the effective video data of each line of the image from the pixel data to obtain video line data; according to the preset odd and even line separation rule, allocate the odd-numbered video line data to the odd-numbered image buffer and allocate the even-numbered video line data to the even-numbered image buffer.

[0014] S3. Monitor the write status of the odd-numbered and even-numbered image buffers in real time and maintain the write status parameters, which include the image frame start identifier, image frame sequence number, and video line data line number information.

[0015] The image frame number is used to identify the image frame to which the currently stored video line data belongs;

[0016] The line number information is used to identify the line position of the currently stored video line data in the image frame.

[0017] S4. Based on the field synchronization signal and write status parameters, extract video line data alternately from the odd-numbered line image buffer and the even-numbered line image buffer;

[0018] S5. Based on the preset number of line image frames, the extracted odd-numbered line video data and even-numbered line video data are framed according to the Fibre Channel digital video transmission protocol to obtain odd-numbered line data frames and even-numbered line data frames.

[0019] S6. Through two independent fiber channel MAC (Media Access Control) units, odd-numbered line data frames and even-numbered line data frames are sent to the corresponding fiber links respectively, and the frame alignment and interline alignment of the data streams in the two fiber links are maintained during the transmission process.

[0020] Furthermore, in S2, the odd-even row separation rule is as follows: for each frame of image, its 1st, 3rd, 5th... video row data are classified as odd-numbered video row data, and its 2nd, 4th, 6th... video row data are classified as even-numbered video row data.

[0021] Furthermore, in S2, both the odd-numbered row image buffer and the even-numbered row image buffer adopt a ping-pong buffer structure. Each buffer includes at least a first storage block and a second storage block, and the size of each storage block is the storage space required for one row of video data.

[0022] While the first storage block is being written, the second storage block is available for reading; while the second storage block is being written, the first storage block is available for reading, so that the writing and reading operations of video line data overlap in time.

[0023] Furthermore, in S3, the write status parameters also include:

[0024] The currently valid storage block identifier indicates whether the first or second storage block is currently available for reading.

[0025] Furthermore, in S4, the method for alternately extracting video line data is as follows:

[0026] When a field synchronization signal is detected, an operation is triggered to extract the first line of video line data from the odd-numbered and even-numbered image buffers based on the currently valid storage block identifier;

[0027] When no field synchronization signal is detected, subsequent video line data are extracted sequentially from the odd-numbered and even-numbered image buffers based on the current valid storage block identifier and line number information.

[0028] Furthermore, in S5, the method for framing is as follows:

[0029] Based on the row number information, image frame sequence number and preset row image frame number corresponding to the current video row data, the video row data is divided into frames, and a protocol frame header, payload and CRC (Cyclic Redundancy Check) field are added to each frame unit.

[0030] Furthermore, in S6, the method for maintaining frame alignment and interline alignment of data streams in two fiber optic links is as follows:

[0031] The transmission of two optical fiber links is initiated based on the same field synchronization signal;

[0032] During transmission, the start time, line interval, and end time of transmission for odd-numbered and even-numbered data frames are kept consistent, based on the same line counting rules and transmission interval settings.

[0033] The system monitors the field synchronization signal, line count, and line number information and image frame sequence number corresponding to the currently transmitted data frame in the two fiber optic links in real time, and schedules the transmission timing of the two fiber optic links.

[0034] An airborne digital video transmission and control system based on dual fiber optic channels for implementing the above method includes:

[0035] The video acquisition unit is used to acquire the raw video signal of image frames;

[0036] A field synchronization detection unit, connected to the video acquisition unit, is used to detect the field synchronization signal to identify the start of an image frame;

[0037] The line image management unit is connected to the field synchronization detection unit and the video acquisition unit. It is used to capture valid video data of each line of image from the pixel data according to the field synchronization signal and the line synchronization signal to obtain video line data; and according to the preset odd and even line separation rules, it allocates the odd-numbered video line data to the odd-numbered image buffer and the even-numbered video line data to the even-numbered image buffer.

[0038] The odd-numbered row image buffer and the even-numbered row image buffer are respectively connected to the row image management unit and are used to store the odd-numbered row video line data and the even-numbered row video line data;

[0039] A status monitoring unit is connected to the odd-numbered row image buffer and the even-numbered row image buffer, and is used to monitor the write status of the odd-numbered row image buffer and the even-numbered row image buffer in real time and feed it back to the row image management unit;

[0040] The register group, connected to the line image management unit, is used to store the preset number of line image frames and the write status parameters maintained by the line image management unit;

[0041] A send scheduler, connected to the field synchronization detection unit and register group, is used to alternately extract video line data from the odd-numbered line image buffer and the even-numbered line image buffer according to the field synchronization signal and write status parameters;

[0042] The odd-line framing unit and the even-line framing unit are respectively connected to the transmission scheduler, and are used to frame the extracted odd-line video line data and even-line video line data according to the Fibre Channel digital video transmission protocol to obtain odd-line data frames and even-line data frames.

[0043] Fiber Channel 1 MAC unit and Fiber Channel 2 MAC unit are respectively connected to the output end of the odd-numbered row framing unit and the output end of the even-numbered row framing unit, and are used to send the odd-numbered row data frames and even-numbered row data frames to the corresponding fiber optic links respectively.

[0044] The dual-channel transmission control unit is connected to the line image management unit, the odd-numbered line framing unit, the even-numbered line framing unit, the fiber channel 1 MAC unit, the fiber channel 2 MAC unit, and the transmission scheduler, and is used to maintain frame alignment and interline alignment of the data streams in the two fiber optic links.

[0045] Furthermore, the register set includes:

[0046] An image frame start identifier register, which is connected to the line image management unit and the transmission scheduler, is used to store the image frame start identifier;

[0047] An image frame sequence number register, which is connected to the row image management unit, the odd row framing unit and the even row framing unit, is used to store the image frame sequence number;

[0048] A line number information register, which is connected to the line image management unit, the transmission scheduler, the odd-numbered line framing unit, and the even-numbered line framing unit, is used to store the line number information of the video line data;

[0049] The currently valid storage block register, which is connected to the row image management unit and the transmission scheduler, is used to store the currently valid storage block identifier;

[0050] The line image frame count register, which is connected to the odd-numbered line frame unit and the even-numbered line frame unit, is used to store the preset line image frame count.

[0051] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0052] (1) This invention splits a single high-bandwidth digital video signal into two independent video data streams according to the odd-even row separation rule, and uses two independent optical fiber channels for parallel transmission. This effectively breaks through the bandwidth limitation of a single optical fiber channel, and can meet the real-time transmission requirements of airborne mission systems for ultra-high resolution and high frame rate digital video without reducing the resolution or using lossy compression, thus ensuring the integrity of the original video information.

[0053] (2) This invention ensures that the start time, line interval, and end time of the two channels are strictly synchronized when sending the same video frame by globally coordinating the transmission timing of the two channels, combined with the precise frame start provided by the field synchronization signal and the real-time monitoring of the buffer write status parameters. This provides a reliable timing basis for the lossless reconstruction of the complete image at the receiving end. The ping-pong buffer mechanism allows the writing and reading of video data to overlap in time, realizing a pipelined operation of continuous acquisition and alternating transmission, effectively avoiding data transmission bottlenecks and ensuring the continuity and correctness of data transmission.

[0054] (3) This invention constructs a complete hardware implementation architecture through the collaborative work of a video acquisition unit, a field synchronization detection unit, a line image management unit, a status monitoring unit, a register group, a transmission scheduler, a framing unit, a MAC unit, and a dual-channel transmission control unit. The odd-numbered and even-numbered line image buffers adopt a ping-pong structure, with each buffer including a first storage block and a second storage block, enabling parallel write and read operations. The register group stores the write status parameters maintained by the line image management unit, providing real-time status information support for each functional unit. The dual-channel transmission control unit monitors the transmission progress of the two channels and actively corrects timing deviations when detected, ensuring strict synchronization of the two channels. Attached Figure Description

[0055] Figure 1 This is a structural block diagram of an airborne digital video transmission control system based on dual fiber optic channels provided in Embodiment 1 of the present invention.

[0056] Figure 2 The flowchart illustrates the airborne digital video transmission control method based on dual fiber optic channels provided in Embodiment 1 of the present invention. Detailed Implementation

[0057] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0058] Example 1

[0059] refer to Figure 1 This embodiment provides an airborne digital video transmission control system based on dual fiber optic channels, including a video acquisition unit, a field synchronization detection unit, a line image management unit, an odd-numbered line image buffer, an even-numbered line image buffer, a status monitoring unit, a register group, a transmission scheduler, an odd-numbered line framing unit, an even-numbered line framing unit, a fiber optic channel 1 MAC unit, a fiber optic channel 2 MAC unit, and a dual-channel transmission control unit.

[0060] The register group includes: image frame start identifier register, image frame sequence number register, line number information register, current valid storage block register, and line image frame number register.

[0061] Both the odd-numbered and even-numbered image buffers employ a ping-pong buffer structure. Each buffer includes at least a first storage block and a second storage block, with each block being the size of the storage space required for one line of video data. While the first storage block is being written to, the second storage block is available for reading; conversely, while the second storage block is being written to, the first storage block is available for reading, thus enabling the writing and reading operations of video line data to overlap in time.

[0062] The connection relationships of the various functional units of the system provided in this embodiment are as follows:

[0063] The input end of the video acquisition unit is connected to an external video source, and the output end is connected to the input end of the field synchronization detection unit and the input end of the line image management unit.

[0064] The output of the field synchronization detection unit is connected to the input of the line image management unit and the input of the transmission scheduler;

[0065] The output of the row image management unit is connected to the input of the odd row image buffer, the input of the even row image buffer, and the input of the dual-channel transmission control unit, respectively.

[0066] The output terminals of the odd-numbered row image buffers are respectively connected to the input terminals of the status monitoring unit and the transmission scheduler;

[0067] The output terminals of the even-numbered row image buffers are respectively connected to the input terminals of the status monitoring unit and the transmission scheduler;

[0068] Image frame start identifier register, which is connected to the line image management unit and the transmission scheduler;

[0069] An image frame sequence number register is connected to the row image management unit, the odd row framing unit, and the even row framing unit;

[0070] A row number information register is connected to the row image management unit, the transmission scheduler, the odd row framing unit, and the even row framing unit;

[0071] The currently active storage block register is connected to the row image management unit and the transmission scheduler;

[0072] The line image frame count register is connected to the odd-numbered line framing unit and the even-numbered line framing unit.

[0073] The input terminal of the transmitting scheduler is also connected to the output terminal of the dual-channel transmission control unit. The output terminal of the transmitting scheduler is connected to the input terminal of the odd-numbered row framing unit, the input terminal of the even-numbered row framing unit, and the input terminal of the dual-channel transmission control unit, respectively.

[0074] The output of the odd-row framing unit is connected to the data input of the Fiber Channel 1 MAC unit and the input of the dual-channel transmission control unit;

[0075] The output of the even-row framing unit is connected to the data input of the Fiber Channel 2 MAC unit and the input of the dual-channel transmission control unit;

[0076] The fiber channel 1 MAC unit has its first output connected to the input of the dual-channel transmission control unit, its second output connected to the first fiber optic link, and its control input connected to the output of the dual-channel transmission control unit.

[0077] The fiber channel 2 MAC unit has its first output connected to the input of the dual-channel transmission control unit, its second output connected to the second fiber optic link, and its control input connected to the output of the dual-channel transmission control unit.

[0078] Example 2

[0079] refer to Figure 2 Based on the system proposed in Embodiment 1, this embodiment provides an airborne digital video transmission control method based on dual fiber optic channels, which is executed according to the following steps:

[0080] S1. The video acquisition unit acquires raw video signals of image frames from an external video source. The raw video signals include pixel data, field synchronization signals, and line synchronization signals. The video acquisition unit sends the acquired raw video signals to the field synchronization detection unit and the line image management unit.

[0081] The field synchronization detection unit receives the original video signal, detects the field synchronization signal within it, and identifies the start position of each frame using the detected field synchronization signal. The field synchronization detection unit then sends the detected field synchronization signal to the line image management unit.

[0082] S2. The line image management unit receives the raw video signal from the video acquisition unit and the field synchronization signal from the field synchronization detection unit, and performs the following operations:

[0083] Based on the detected field synchronization signal and the line synchronization signal in the original video signal, the effective video data of each line of the image is captured from the pixel data of the original video signal to obtain the video line data.

[0084] The video line data is classified according to a preset odd-even line separation rule. In this embodiment, the odd-even line separation rule is as follows: for each frame of image, the video line data of its 1st, 3rd, 5th... lines are classified as odd-numbered video line data, and the video line data of its 2nd, 4th, 6th... lines are classified as even-numbered video line data;

[0085] The categorized odd-numbered video line data is allocated to the odd-numbered image buffer, and the even-numbered video line data is allocated to the even-numbered image buffer.

[0086] S3. The status monitoring unit monitors the write status of the odd-numbered row image buffer and the even-numbered row image buffer in real time and feeds it back to the row image management unit.

[0087] The write status includes: which storage block is currently being read, the line position of the video line data stored in that storage block within the image frame, and the image frame to which it belongs.

[0088] The row image management unit maintains write status parameters for the odd-numbered row image buffer and the even-numbered row image buffer based on the received write status. The write status parameters include:

[0089] Image frame start identifier, used to mark the beginning of a new image frame;

[0090] Image frame number, used to identify the image frame to which the currently stored video line data belongs;

[0091] The line number information of the video line data is used to identify the line position of the currently stored video line data in the image frame;

[0092] The currently valid storage block identifier indicates whether the storage block currently available for reading is the first or the second storage block.

[0093] The row image management unit stores the maintained write status parameters into the register group, specifically:

[0094] The image frame start identifier is stored in the image frame start identifier register;

[0095] The image frame number is stored in the image frame number register;

[0096] The line number information of the video line data is stored in the line number information register;

[0097] The identifier of the currently valid storage block is stored in the currently valid storage block register.

[0098] S4. The sending scheduler receives the field synchronization signal from the field synchronization detection unit in real time, and at the same time reads the current valid storage block identifier and row number information from the register group.

[0099] The send scheduler, based on the field synchronization signal and the read write status parameters, alternately extracts video line data from the odd-numbered line image buffer and the even-numbered line image buffer. Specifically:

[0100] When the send scheduler detects the field synchronization signal, it indicates the start of a new image frame and triggers the extraction of the first line of video data from the odd-numbered image buffer and the even-numbered image buffer, respectively, based on the currently valid storage block identifier.

[0101] When no new field synchronization signal is detected, the send scheduler extracts subsequent video line data sequentially from the odd-numbered and even-numbered image buffers based on the currently valid storage block identifier and line number information, ensuring that the extraction order is consistent with the line order during writing.

[0102] The send scheduler sends the extracted odd-numbered video line data to the odd-numbered line framing unit and the extracted even-numbered video line data to the even-numbered line framing unit. Simultaneously, it sends the currently read line number information to the dual-channel transmission control unit.

[0103] S5. When the odd-numbered line framing unit receives odd-numbered line video data from the transmitting scheduler, it performs the following operations:

[0104] The system reads the row number information corresponding to the current odd-numbered video row data from the row number information register; reads the image frame sequence number corresponding to the current odd-numbered video row data from the image frame sequence number register; reads the preset number of row image frames from the row image frame count register; and performs frame segmentation processing on the received odd-numbered video row data according to the read number of row image frames, the row number information corresponding to the current odd-numbered video row data, and the image frame sequence number. For each frame segmentation unit, a protocol frame header, payload, and CRC field are added to form an odd-numbered row data frame that conforms to the Fibre Channel digital video transmission protocol.

[0105] When the even-numbered line framing unit receives even-numbered line video data from the transmission scheduler, it performs the following operations:

[0106] The system reads the row number information corresponding to the current even-numbered video row data from the row number information register; reads the image frame sequence number corresponding to the current even-numbered video row data from the image frame sequence number register; reads the preset number of row image frames from the row image frame count register; and performs frame segmentation processing on the received even-numbered video row data according to the read number of row image frames, the row number information corresponding to the current even-numbered video row data, and the image frame sequence number. For each frame segmentation unit, a protocol frame header, payload, and CRC field are added to form an even-numbered data frame conforming to the Fibre Channel digital video transmission protocol.

[0107] The odd-numbered row framing unit sends the completed odd-numbered row data frames to the Fiber Channel 1 MAC unit, and simultaneously sends framing progress information to the dual-channel transmission control unit. The framing progress information includes the row number currently being framed, the number of framing units that have completed framing, and other information. The even-numbered row framing unit sends the completed even-numbered row data frames to the Fiber Channel 2 MAC unit, and simultaneously sends framing progress information to the dual-channel transmission control unit.

[0108] S6. The Fiber Channel 1 MAC unit receives odd-numbered row data frames from the odd-numbered row framing unit and transmits the received odd-numbered row data frames via the first fiber optic link through its first output terminal. Simultaneously, the Fiber Channel 1 MAC unit transmits the transmission status information of the first fiber optic link to the dual-channel transmission control unit through its second output terminal. The transmission status information includes the current link's busy / idle status, the number of data frames transmitted, and the link status.

[0109] The Fiber Channel 2 MAC unit receives even-numbered data frames from the even-numbered row framing unit and transmits the received even-numbered data frames via the second fiber optic link through its first output terminal. Simultaneously, the Fiber Channel 2 MAC unit transmits the transmission status information of the second fiber optic link to the dual-channel transmission control unit through its second output terminal.

[0110] The dual-channel transmission control unit coordinates the transmission timing of the two fiber optic links in real time during transmission, maintaining frame alignment and interline alignment of the data streams in the two fiber optic links. Specifically:

[0111] Synchronization Initiation: Based on the same field synchronization signal received from the line image management unit, when the first line data frame (the odd-numbered line data frame and the even-numbered line data frame corresponding to the first line video line data) is framed and sent to the Fiber Channel 1 MAC unit and the Fiber Channel 2 MAC unit, an enable signal is sent to the Fiber Channel 1 MAC unit and the Fiber Channel 2 MAC unit to trigger the two fiber links to start sending the first line data frame simultaneously.

[0112] Process monitoring: Receives field synchronization signals from the line image management unit, line number information from the transmission scheduler, framing progress information from the odd-numbered line framing unit and the even-numbered line framing unit, and transmission status information from the fiber channel 1 MAC unit and the fiber channel 2 MAC unit, and monitors the transmission progress of the two fiber links in real time.

[0113] Timing Preservation: Based on the same line counting rules and transmission interval settings, timing control signals are sent to the transmission scheduler to keep the transmission start time, line interval, and frame end time of odd-numbered and even-numbered data frames consistent.

[0114] Deviation correction: When a deviation in the transmission timing of two fiber optic links is detected, a correction control signal is sent to the transmission scheduler to adjust the rhythm at which the transmission scheduler extracts video line data from the buffer, so that the two fiber optic links are restored to alignment.

[0115] This embodiment, through the above steps, enables the separation of a single high-bandwidth digital video signal by row parity and its parallel transmission through two independent optical fiber channels, while maintaining strict frame alignment and inter-row alignment during transmission. This effectively overcomes the bandwidth limitation of a single optical fiber link and can meet the real-time transmission requirements of airborne mission systems for ultra-high resolution and high frame rate digital video.

[0116] The specific embodiments of the present invention are provided to enable those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention.

[0117] It should be understood that the present invention is not limited to the content already described above, and various modifications and changes can be made without departing from its scope. The scope of the present invention is limited only by the appended claims.

Claims

1. A method for controlling airborne digital video transmission based on dual fiber optic channels, characterized in that, Includes the following steps: S1. Acquire the raw video signal of the image frame, which includes pixel data, field synchronization signal, and line synchronization signal; use the field synchronization signal to identify the start of the image frame; S2. Based on the field synchronization signal and the line synchronization signal, capture the effective video data of each line of the image from the pixel data to obtain video line data; according to the preset odd and even line separation rule, allocate the odd-numbered video line data to the odd-numbered image buffer and allocate the even-numbered video line data to the even-numbered image buffer. S3. Monitor the write status of the odd-numbered and even-numbered image buffers in real time and maintain the write status parameters, which include the image frame start identifier, image frame sequence number, and video line data line number information. The image frame number is used to identify the image frame to which the currently stored video line data belongs; The row number information is used to identify the row position of the currently stored video row data in the image frame; S4. Based on the field synchronization signal and write status parameters, extract video line data alternately from the odd-numbered line image buffer and the even-numbered line image buffer; S5. Based on the preset number of line image frames, the extracted odd-numbered line video data and even-numbered line video data are framed according to the Fibre Channel digital video transmission protocol to obtain odd-numbered line data frames and even-numbered line data frames. S6. Through two independent fiber optic channel MAC units, odd-numbered data frames and even-numbered data frames are sent to the corresponding fiber optic links respectively, and the frame alignment and inter-line alignment of the data streams in the two fiber optic links are maintained during the transmission process.

2. The airborne digital video transmission control method based on dual fiber optic channels according to claim 1, characterized in that, In S2, the odd-even row separation rule is as follows: for each frame of image, the video row data of its 1st row, 3rd row, 5th row... are classified as odd-numbered video row data, and the video row data of its 2nd row, 4th row, 6th row... are classified as even-numbered video row data.

3. The airborne digital video transmission control method based on dual fiber optic channels according to claim 1, characterized in that, In S2, both the odd-numbered row image buffer and the even-numbered row image buffer adopt a ping-pong buffer structure. Each buffer includes at least a first storage block and a second storage block. The size of each storage block is the storage space required for one line of video data. While the first storage block is being written, the second storage block is available for reading; while the second storage block is being written, the first storage block is available for reading, so that the writing and reading operations of video line data overlap in time.

4. The airborne digital video transmission control method based on dual fiber optic channels according to claim 3, characterized in that, In S3, the write status parameters also include: The currently valid storage block identifier indicates whether the first or second storage block is currently available for reading.

5. The airborne digital video transmission control method based on dual fiber optic channels according to claim 4, characterized in that, In S4, the method for alternately extracting video line data is as follows: When a field synchronization signal is detected, an operation is triggered to extract the first line of video line data from the odd-numbered and even-numbered image buffers based on the currently valid storage block identifier; When no field synchronization signal is detected, subsequent video line data are extracted sequentially from the odd-numbered and even-numbered image buffers based on the current valid storage block identifier and line number information.

6. The airborne digital video transmission control method based on dual fiber optic channels according to claim 1, characterized in that, In S5, the method for framing is as follows: Based on the row number information, image frame sequence number and preset row image frame number corresponding to the current video row data, the video row data is divided into frames, and a protocol frame header, payload and CRC field are added to each frame unit.

7. The airborne digital video transmission control method based on dual fiber optic channels according to claim 1, characterized in that, In S6, the method for maintaining frame alignment and interline alignment of data streams in two fiber optic links is as follows: The transmission of two optical fiber links is initiated based on the same field synchronization signal; During transmission, the start time, line interval, and end time of transmission for odd-numbered and even-numbered data frames are kept consistent, based on the same line counting rules and transmission interval settings. The system monitors the field synchronization signal, line count, and line number information and image frame sequence number corresponding to the currently transmitted data frame in the two fiber optic links in real time, and schedules the transmission timing of the two fiber optic links.

8. An airborne digital video transmission and control system based on dual fiber optic channels for implementing the method of any one of claims 1 to 7, characterized in that, include: The video acquisition unit is used to acquire the raw video signal of image frames; A field synchronization detection unit, connected to the video acquisition unit, is used to detect the field synchronization signal to identify the start of an image frame; A line image management unit, connected to the field synchronization detection unit and the video acquisition unit, is used to capture valid video data of each line image from the pixel data according to the field synchronization signal and the line synchronization signal, so as to obtain video line data; According to the preset odd-even line separation rules, odd-numbered video line data is allocated to odd-numbered image buffers, and even-numbered video line data is allocated to even-numbered image buffers. The odd-numbered row image buffer and the even-numbered row image buffer are respectively connected to the row image management unit and are used to store the odd-numbered row video line data and the even-numbered row video line data; A status monitoring unit is connected to the odd-numbered row image buffer and the even-numbered row image buffer, and is used to monitor the write status of the odd-numbered row image buffer and the even-numbered row image buffer in real time and feed it back to the row image management unit; The register group, connected to the line image management unit, is used to store the preset number of line image frames and the write status parameters maintained by the line image management unit; A send scheduler, connected to the field synchronization detection unit and register group, is used to alternately extract video line data from the odd-numbered line image buffer and the even-numbered line image buffer according to the field synchronization signal and write status parameters; The odd-line framing unit and the even-line framing unit are respectively connected to the transmission scheduler, and are used to frame the extracted odd-line video line data and even-line video line data according to the Fibre Channel digital video transmission protocol to obtain odd-line data frames and even-line data frames. Fiber Channel 1 MAC unit and Fiber Channel 2 MAC unit are respectively connected to the output end of the odd-numbered row framing unit and the output end of the even-numbered row framing unit, and are used to send the odd-numbered row data frames and even-numbered row data frames to the corresponding fiber optic links respectively. The dual-channel transmission control unit is connected to the line image management unit, the odd-numbered line framing unit, the even-numbered line framing unit, the fiber channel 1 MAC unit, the fiber channel 2 MAC unit, and the transmission scheduler, and is used to maintain frame alignment and interline alignment of the data streams in the two fiber optic links.

9. The airborne digital video transmission and control system based on dual fiber optic channels according to claim 8, characterized in that, The register group includes: An image frame start identifier register, which is connected to the line image management unit and the transmission scheduler, is used to store the image frame start identifier; An image frame sequence number register, which is connected to the row image management unit, the odd row framing unit and the even row framing unit, is used to store the image frame sequence number; A line number information register, which is connected to the line image management unit, the transmission scheduler, the odd-numbered line framing unit, and the even-numbered line framing unit, is used to store the line number information of the video line data; The currently valid storage block register, which is connected to the row image management unit and the transmission scheduler, is used to store the currently valid storage block identifier; The line image frame count register, which is connected to the odd-numbered line frame unit and the even-numbered line frame unit, is used to store the preset line image frame count.

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