Slave device in a multimedia transmission system and multimedia transmission system
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- 3PEAK INC
- Filing Date
- 2026-01-30
- Publication Date
- 2026-06-05
AI Technical Summary
Existing daisy-chain topology multimedia transmission systems suffer from significant node processing latency when processing real-time data, leading to problems such as audio and video desynchronization. In particular, the accumulated latency severely impacts system performance as the number of nodes increases.
In the slave node device of the multimedia transmission system, a receiving module, a sending module, a parsing module, an encoding module, a control signal generation unit, and a data path switching module are introduced. The optimal data path is selected for data transmission through a preset strategy to reduce node processing latency.
The node latency of the slave devices is reduced, thereby reducing the overall latency of the multimedia transmission system and improving system performance.
Smart Images
Figure CN122160306A_ABST
Abstract
Description
Technical Field
[0001] This disclosure pertains to the field of data transmission technology, and particularly relates to a slave node device and a multimedia transmission system in a multimedia transmission system. Background Technology
[0002] Modern automobiles integrate electronic control units (ECUs) and an increasing number of multimedia devices, requiring high-speed, reliable audio and video transmission between these devices. This has led to the development of wired high-speed multimedia transmission systems with a daisy-chain topology. In this system, audio and video data frames are sequentially passed from one node to the next. However, this topology faces challenges when processing real-time data requiring low latency. When an audio or video data frame passes through each slave node on the link, the traditional processing method requires receiving and buffering the entire frame, then having that node insert, modify, or read the data before reassembling and sending it to the next node. This store-and-forward processing introduces significant node processing latency. As the number of nodes increases, the accumulated latency severely impacts the performance of real-time applications, causing problems such as audio and video desynchronization. Summary of the Invention
[0003] To address the aforementioned issues, embodiments of this disclosure provide a slave node device and a multimedia transmission system.
[0004] In a first aspect, embodiments of this disclosure provide a slave node device in a multimedia transmission system, the multimedia transmission system including a master node and a plurality of slave node devices connected in a daisy-chain topology, the slave node devices including:
[0005] The receiving module is used to receive data frames from the upstream node;
[0006] The sending module is used to send data frames to downstream nodes;
[0007] The parsing module is used to parse the received data frames and store the parsed data in the bus data buffer.
[0008] The encoding module is used to read data from the bus data buffer or the local data buffer according to the data selection control signal, encode the data, and then output it.
[0009] A control signal generation unit is used to generate the data selection control signal according to a preset strategy and data transmission status.
[0010] The data path switching module is used to select a control signal based on the data and use the output of the receiving module or the encoding module as the input of the transmitting module.
[0011] In some embodiments, the data path switching module is implemented using a hardware selector, wherein the first input terminal and the second input terminal of the hardware selector are respectively connected to the outputs of the receiving module and the encoding module, and the control terminal receives the data selection control signal.
[0012] In some embodiments, the control signal generation unit includes a counter, and the control signal generation unit generates the data selection control signal according to a preset strategy and the count value of the counter.
[0013] In some embodiments, when the slave node device simply forwards the received data frames, the input of the sending module is always the direct data output of the receiving module throughout the entire sending process.
[0014] In some embodiments, when the slave node device needs to replace part of the data in the forwarded data frame, during the period of sending the replacement data, the input of the sending module is switched to the encoded output of the data read from the local data buffer by the encoding module, and during the period of sending subsequent data, the input of the sending module is switched to the encoded output of the data read from the bus data buffer by the encoding module.
[0015] In some embodiments, when the slave node device needs to add some data to the forwarded data frame, during the period of sending the added data, the input of the sending module is switched to the encoded output of the data read from the local data buffer by the encoding module, and during the period of sending subsequent data, the input of the sending module is switched to the encoded output of the data read from the bus data buffer by the encoding module.
[0016] In some embodiments, the preset strategy is used to indicate whether the received data frame is to be directly forwarded, replaced, or local data is added. If local data is to be replaced or added, the location of replacement or addition must also be indicated.
[0017] In some embodiments, the bus data buffer and the local data buffer are constructed using registers.
[0018] In some embodiments, the preset policy is broadcast by the master node to multiple slave node devices.
[0019] Secondly, embodiments of this disclosure provide a multimedia transmission system, including multiple slave node devices as described above and a master node, wherein the master node and the multiple slave node devices constitute a daisy-chain network.
[0020] In summary, the slave node device provided in this embodiment selects the optimal data path from multiple data paths for the entire data frame or the various parts decomposed from the data frame according to a preset strategy, and uses the optimal data path to send the entire data frame or the corresponding parts decomposed from the data frame, thereby reducing the node latency of the slave node device and thus reducing the overall latency of the multimedia transmission system. Attached Figure Description
[0021] The above and other objects, features and advantages of the present disclosure will become clearer from the following description of embodiments of the present disclosure with reference to the accompanying drawings, in which:
[0022] Figure 1 This is a network topology diagram of a multimedia transmission system;
[0023] Figure 2 It shows Figure 1 The data in the process of processing from the node;
[0024] Figure 3 A schematic diagram of the structure of the slave node device proposed in the embodiments of this disclosure is provided;
[0025] Figure 4 A schematic diagram showing the connection relationship between the data path switching module, the encoding module, and the control signal generation unit in some embodiments of this disclosure is provided. Detailed Implementation
[0026] Embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. In the various drawings, the same elements are indicated by similar reference numerals. For clarity, the various parts in the drawings are not drawn to scale. Furthermore, certain well-known parts may not be shown.
[0027] The following description of embodiments of the present disclosure is based on examples, but the embodiments of the present disclosure are not limited to these embodiments. In the detailed description of the embodiments of the present disclosure below, certain specific details are described in detail. Those skilled in the art can fully understand the embodiments of the present disclosure without these details. To avoid obscuring the essence of the embodiments of the present disclosure, well-known methods, processes, flows, elements, and circuits are not described in detail.
[0028] Unless the context explicitly requires it, the terms "comprising," "including," and similar terms throughout the specification and claims should be interpreted as encompassing rather than exclusive or exhaustive; that is, meaning "including but not limited to." Furthermore, in the description of embodiments of this disclosure, unless otherwise stated, "a plurality of" means two or more.
[0029] Figure 1This is a network diagram of a multimedia transmission system, consisting of a master node and slave nodes 1 to N, forming a daisy-chain network. This multimedia transmission system is, for example, a time-division duplex (TDM) system for high-speed wired media transmission in a vehicle. This system uses TDM mode to achieve high-speed data transmission and supports the transmission of audio, video, and control signals. In this system, the master node, for example, is the main control unit, responsible for link management and data scheduling. The slave nodes connect to various terminal devices distributed in the vehicle environment, such as displays, cameras, or audio systems. Each slave node processes the received data before forwarding it.
[0030] like Figure 1 As shown, the data transmission in this system can be represented as follows: Within a superframe, the master node first sends a downlink data frame downstream, containing the data the master node intends to send. After receiving the downlink data frame from the master node, node 1 parses it and sends it to downstream node 2. During node 1's processing, in addition to directly forwarding the downlink data frame, it may also involve adding or replacing data in the downlink data frame. This process continues until the last node N. After receiving the downlink data frame from node N-1, node N waits a fixed time before sending an uplink data frame upstream. Through a transmission process similar to that of the downlink data frame, the master node finally receives the uplink data frame, and a superframe ends. In the figure, IDLE represents the time value between the two moments when the slave node completes the transmission of the downlink data frame and begins to send the uplink data frame.
[0031] During this process, the master node can distribute data to each node through downlink data frames, and the slave nodes can also send data back to the master node through uplink data frames. Data exchange between slave nodes is also allowed.
[0032] Within a superframe, besides the bandwidth occupied by normal uplink and downlink data frames, a significant portion of the bandwidth is consumed by the processing latency T_Node_delay of each node. Assuming a transmission system with N slave nodes, there will be a bandwidth waste of 2N*T_Node_delay. This bandwidth waste reduces the actual bandwidth available for data transmission, preventing the system from transmitting more data and causing a decline in performance metrics. Furthermore, higher latency between nodes may also affect clock synchronization between different nodes.
[0033] refer to Figure 2 As shown, the slave node device 200 is Figure 1 The slave node 200 is any one of the slave nodes 1 to N shown. The slave node device 200 includes a receiving module 201, a parsing module 202, a data buffer 203, an encoding module 204, and a sending module 205.
[0034] according to Figure 1The processing delay of the node device 300 is as follows: T_Node_dly = T1_bus_dly + T2_rec_dly + T3_upk_dly + T4_buf_dly + T5_pk_dly + T6_trans_dly. T1_bus_dly represents the time taken by the receiving module 201 to receive downlink data frames, T2_rec_dly is the time taken by the parsing module 202 to receive data from the receiving module 201, T3_upk_dly is the time taken by the parsing module 202 to parse the data frames and store them in the data buffer 203, T4_buf_dly is the time taken to write data to or read data from the data buffer 203, T5_pk_dly is the time taken by the encoding module 204 to encode the read data, and T6_trans_dly is the transmission time of the downlink data frames.
[0035] To reduce processing latency of slave node devices, embodiments of this disclosure address... Figure 2 Improvements are proposed to the hardware and software functions of the slave node device 200 shown. Figure 3 A schematic diagram of the improved slave node device 300 is provided. As shown in the figure, the slave node device 300 includes a receiving module 301, a parsing module 302, a bus data buffer 303, a local data buffer 304, an encoding module 305, a transmitting module 306, a data path switching module 307, and a control signal generation unit 308.
[0036] The receiving module 301 receives data frames from the upstream node. The parsing module 302 parses the data frames and stores the parsed data in the bus data buffer 303. The local data buffer 304 is used to buffer local data, which is used to add or replace parts of the data frame. The encoding module 305 receives a data selection control signal, reads data from the bus data buffer 303 or the local data buffer 304 according to the data selection control signal, encodes the data, and outputs it. The data selection control signal is a timing control signal used to control the encoding module 305 to read data from the bus data buffer 303 or the local data buffer 304 and encode it at the appropriate timing. The bus data buffer 303 and the local data buffer 304 can each be implemented in various ways, such as using two independent FIFOs (first-in, first-out memories) or data registers.
[0037] The control signal generation unit 308 reads a preset strategy from the configuration register. The preset strategy in the configuration register is used to indicate whether the received data frame is directly forwarded, replaced, or local data is added. If local data is replaced or added, the replacement or addition position also needs to be indicated. The control signal generation unit 308 generates a data selection control signal by combining the preset strategy and the current data transmission status. For example, the preset strategy is [0,48]: 0; [49,64]: 1, which means that in the data frame, the data segment indicated by [0,48] is directly forwarded, and the data segment indicated by [49,64] is replaced by local data.
[0038] In some embodiments, the control signal generation unit 308 includes a counter that counts the encoded data of the encoding module 30. The control signal generation unit 308 generates a data selection control signal based on the count value. The counter needs to be cleared before the start of a downlink data frame. The master node can send a broadcast notification to each slave node device to clear the counter before each downlink data frame is sent, so as to clear the counter in each slave node device.
[0039] The data path switching module 307 switches the data source according to the data selection control signal. This data source includes the direct outputs of the receiving module 301 and the encoding module 305. The output of the data path switching module 307 is the direct input of the sending module 306. The sending module 306 then sends the data frames received from the data path switching module 307 to the downstream node.
[0040] Accordingly, via the data path switching module 307, the node device 300 switches between three data paths for the received data frame: the first data path is that the data is transmitted from the receiving module 301 to the sending module 306 without parsing and encoding; the second data path is that the data is read from the local data buffer 304, encoded by the encoding module 305, and then output to the sending module 306; the third data path is that the data is parsed from the receiving module 301 by the parsing module 302, stored in the bus data buffer 303, and then read and encoded by the encoding module 305 before being sent to the sending module 306.
[0041] If the slave node device 300 only forwards data (e.g., broadcasts), then the first data path is used exclusively. In this case, assuming the time taken for the receiving module 201 to receive a data frame is T1_bus_dly, the processing time of the data path switching module 307 is negligible, the time taken for the sending module 306 to receive data from the receiving module 301 is T2_rec_dly, and the time taken for the sending module 205 to send a data frame is T6_trans_dly, then the node latency of the slave node device 300 is: T1_bus_dly + T2_rec_dly + T6_trans_dly. The time taken for the slave node device 300 to parse the data frame and store it in the bus data buffer 303 is not included in the node latency since the data frame has already been sent.
[0042] If the slave node device 300 needs to replace a data frame, and if the data frame is represented as [D1, D2, D3] and needs to be replaced with [D1, L1, D3], then: when the slave node 300 sends D1, it still uses the first data path; when sending L1, the encoding module 305 prepares the data to be replaced in advance (from the local data buffer 304), and switches to the second data path when L1 needs to be sent; when D3 needs to be sent, the original D3 data has already been stored in the bus data buffer 303 when the slave node 300 sent L1, and the data path switching module 307 switches to the third data path. In this case, the node delay of the slave node device 300 consists of the delays of the first data path, the second data path, and the third data path, and the node delay is less than the delay of the entire process using the first data path, the second data path, and the third data path. Figure 2 The node latency of the data path.
[0043] If the slave node device 300 needs to add a new data frame, and if the data frame is represented as [D1, D2], and the data frame to be sent is [D1, L1, D2], then: sending D1 uses the first data path; sending L1 uses the second data path; and sending D2 uses the third data path. In this case, the node delay of the slave node device 300 is also composed of the delays of the first, second, and third data paths, and the node delay is also less than that of the entire process using [the third data path]. Figure 2 The node latency of the data path.
[0044] Figure 4A schematic diagram illustrating the connection relationship between the data path switching module, the encoding module, and the control signal generation unit in some embodiments of this disclosure is provided. As shown in the figure, the data path switching module 307 uses a hardware selector to implement data path switching. The two inputs of the selector are respectively connected to the outputs of the receiving module 301 and the encoding module 305, and the control terminal receives the data selection control signal Sel. The two inputs of the encoding module 305 are the bus data buffer 303 and the local data buffer 304, respectively.
[0045] There are three data sources: direct bus forwarding data, node-generated data, and locally cached data. The data selection control signal Sel is 0b'00 to enable direct bus forwarding data, 0b'01 to enable node-generated data, and 0b'10 to enable bus cached data.
[0046] The specific example of the data selection control signal Sel is as follows. The length of data received and transmitted by the current node is fixed and will not change throughout the entire system operation. If the received data is [D0, D1, D2, D3, D4], and new data L1 and L2 are to be inserted to form a new frame [D0, D1, L1, L2, D2, D3, D4] for transmission, then when transmitting D0 and D1, the data selection control signal Sel is 0'b00; when transmitting L1 and L2, the data selection control signal Sel is 0'b01; and when transmitting D2, D3, and D4, the data selection signal is 0'b10.
[0047] If the received data is [D0, D1, D2, D3, D4], and D1 and D2 are to be replaced with new data L1 and L2 to form a new frame [D0, L1, L2, D3, D4] for transmission, then when transmitting D0 and D1, the data selection control signal Sel is 0'b00; when transmitting L1 and L2, the data selection control signal Sel is 0'b01; and when transmitting D3 and D4, the data selection control signal Sel is 0'b00.
[0048] The data selection control signal Sel is generated by the control signal generation unit 308. In some embodiments, the control signal generation unit 308 is constructed using a system state machine. For example, the system state machine monitors the data transmission status of the receiving module 301 and the encoding module 305 and switches between different states. The control signal generation unit 308 generates different data selection control signals according to different states.
[0049] In summary, the slave node device provided in this embodiment selects the optimal data path from multiple data paths for the entire data frame or the various parts decomposed from the data frame according to a preset strategy, and uses the optimal data path to send the entire data frame or the corresponding parts decomposed from the data frame, thereby reducing the node latency of the slave node device and thus reducing the overall latency of the multimedia transmission system.
[0050] The embodiments of this disclosure are as described above. These embodiments do not exhaustively describe all details, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and variations can be made based on the above description. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the embodiments of this disclosure, thereby enabling those skilled in the art to make good use of the embodiments of this disclosure and modifications based on them. The embodiments of this disclosure are limited only by the claims and their full scope and equivalents.
Claims
1. A slave node device in a multimedia transmission system, the multimedia transmission system comprising a master node and a plurality of said slave node devices connected in a daisy-chain topology, characterized in that, The slave node device includes: The receiving module is used to receive data frames from the upstream node; The sending module is used to send data frames to downstream nodes; The parsing module is used to parse the received data frames and store the parsed data in the bus data buffer. The encoding module is used to read data from the bus data buffer or the local data buffer according to the data selection control signal, encode the data, and then output it. A control signal generation unit is used to generate the data selection control signal according to a preset strategy and data transmission status. The data path switching module is used to select a control signal based on the data and use the output of the receiving module or the encoding module as the input of the transmitting module.
2. The slave node device according to claim 1, characterized in that, The data path switching module is implemented using a hardware selector. The first and second input terminals of the hardware selector are respectively connected to the outputs of the receiving module and the encoding module, and the control terminal receives the data selection control signal.
3. The slave node device according to claim 1, characterized in that, The control signal generation unit includes a counter, and the control signal generation unit generates the data selection control signal according to a preset strategy and the count value of the counter.
4. The slave node device according to any one of claims 1 to 3, characterized in that, When the slave node device simply forwards the received data frame, the input of the sending module is always the direct data output of the receiving module throughout the entire sending process.
5. The slave node device according to any one of claims 1 to 3, characterized in that, When the slave node device needs to replace part of the data in the forwarded data frame, during the period of sending the replacement data, the input of the sending module is switched to the encoding output of the data read from the local data buffer by the encoding module, and during the period of sending subsequent data, the input of the sending module is switched to the encoding output of the data read from the bus data buffer by the encoding module.
6. The slave node device according to any one of claims 1 to 3, characterized in that, When the slave node device needs to add some data to the forwarded data frame, during the period of sending the added data, the input of the sending module is switched to the encoding output of the data read from the local data buffer by the encoding module, and during the period of sending subsequent data, the input of the sending module is switched to the encoding output of the data read from the bus data buffer by the encoding module.
7. The slave node device according to claim 1, characterized in that, The preset strategy is used to indicate whether the received data frame is to be directly forwarded, replaced, or local data is added. If local data is to be replaced or added, the location of replacement or addition must also be indicated.
8. The slave node device according to claim 1, characterized in that, The bus data buffer and the local data buffer are constructed using registers.
9. The slave node device according to claim 1, characterized in that, The preset strategy is broadcast by the master node to multiple slave node devices.
10. A multimedia transmission system comprising a plurality of slave node devices as described in any one of claims 1 to 9 and a master node, wherein the master node and the plurality of slave node devices constitute a daisy-chain network.