Method and system for seamless handover of signals between heterogeneous broadcast television networks

Abstract

The application discloses a signal seamless switching method and system between broadcast television heterogeneous networks, and relates to the technical field of fusion transmission of broadcast television and broadband communication, which comprises the following steps: when a receiving terminal decodes a first audio and video stream in a first network, a second link is established to receive a second audio and video stream, a frame coding type identifier of the second audio and video stream is extracted to locate an intra-frame coded frame, when switching is needed, the first audio and video stream is kept to be decoded, the second audio and video stream is buffered, and the arrival of the intra-frame coded frame is monitored, after the next intra-frame coded frame is detected, the decoder input source is switched to the second audio and video stream data starting from the intra-frame coded frame when the current frame decoding is completed. The application performs switching at the boundary of the intra-frame coded frame, the decoder can continuously output without resetting, and the screen tearing and freezing caused by the heterogeneous network switching are eliminated.

Description

Technical Field

[0001] This invention relates to the field of converged transmission technology of broadcast television and broadband communication, and specifically to a method and system for seamless signal switching between heterogeneous broadcast television networks. Background Technology

[0002] In scenarios where broadcast television networks and broadband networks overlap, receiving terminals need to dynamically switch between the two networks based on signal conditions to ensure service continuity. Broadcast television networks (such as DTMB and DVB-T2) and broadband networks (such as 5G NR and Wi-Fi) differ significantly in their media distribution mechanisms: the former often uses constant bitrate encapsulation such as MPEG-2 TS, while the latter commonly uses slice-based adaptive streaming protocols such as DASH, HLS, or FLV. The video streams output from these two links are typically encoded independently, have different group of picture objects (GOP) structures, and the frame-level timestamps are independent of the encapsulation order.

[0003] When a terminal performs a network handover, the video data from the new link is directly sent to the decoder. If the first frame entering the decoder is not an intra-coded frame (I-frame), the decoder cannot start decoding normally from that frame and must discard the data and wait for the next I-frame. This waiting period typically lasts for a full GOP interval, during which the screen freezes or goes black. If the decoder forcibly decodes non-I-frames without discarding them, it will result in a distorted screen. Furthermore, the two encapsulation protocols, in cases of discontinuous timestamps or sequence number resets, can cause overflow or underflow in the decoding buffer, potentially triggering a decoder restart and causing a second-level interruption. These factors make it difficult for existing handover schemes to achieve a truly seamless user experience.

[0004] Therefore, a seamless signal switching method and system between heterogeneous broadcast television networks is needed to solve the problems existing in the prior art. Summary of the Invention

[0005] The present invention aims to at least partially solve one of the technical problems in the above-mentioned technologies.

[0006] To achieve the above objectives, the first aspect of this invention proposes a seamless signal switching method between heterogeneous broadcast television networks, comprising the following steps: S1: Heterogeneous network link establishment and reception—During the process of receiving and decoding a first audio / video stream through a first network link, the receiving terminal establishes a second link with a second network and receives a second audio / video stream distributed via the second network, wherein the first audio / video stream and the second audio / video stream correspond to heterogeneous network transmission versions of the same program content; S2: Frame coding type identifier extraction and intra-frame coded frame location—The frame coding type identifier is extracted from the encapsulation layer of the second audio / video stream, and the position of each intra-frame coded frame in the second audio / video stream is determined based on the identifier; S3: Switching decision and… Intra-coded frame monitoring—When it is determined that a network switch needs to be performed based on the measurement results of the first network link, the receiving terminal does not immediately interrupt the output of the first audio and video stream, but continues to decode and output the first audio and video stream. At the same time, it buffers the received second audio and video stream data in the terminal buffer and checks the frame encoding type identifier of the buffered data to determine the arrival of the intra-coded frame; S4: Decoder input source switching based on intra-coded frame alignment—After detecting the next intra-coded frame in the second audio and video stream, after the receiving terminal has decoded the current frame of the first audio and video stream, it switches the input source of the decoder to the second audio and video stream data starting from the intra-coded frame in the buffer.

[0007] In addition, the seamless signal switching method between heterogeneous broadcast television networks proposed above according to the present invention may also have the following additional technical features:

[0008] Furthermore, the frame encoding type identifier is written by the sending end into the private descriptor of the Transport Stream (TS) packet, the extended header field of the Real-Time Transport Protocol (RTP) packet, or the Media Presentation Description (MPD) file or fragment index of the Hypertext Transfer Protocol Adaptive Streaming (DASH / HLS) when encapsulating the second audio and video stream.

[0009] Furthermore, the first audio / video stream and the second audio / video stream have at least one different encoding parameter: encoding standard, group of pictures (GOP) length, resolution, bitrate, or encapsulation protocol.

[0010] Furthermore, in S3, the terminal buffer is a joint frame buffer, which simultaneously caches the frame data of the first audio / video stream and the second audio / video stream in alignment with the frame index; before switching the input source of the decoder to the second audio / video stream data starting from the intra-coded frame, the second audio / video stream data in the buffer before the intra-coded frame is discarded.

[0011] Furthermore, the transmitting end forces the audio and video streams distributed to the first network and the second network to set an aligned picture group (GOP) structure, so that the intra-coded frames in the two streams appear in time alignment. In S3, the receiving terminal predicts the arrival time of the intra-coded frames in the second audio and video stream based on the alignment relationship.

[0012] Furthermore, the sending end attaches a unified frame index identifier to the video frames distributed to the first network and the second network. In S4, the receiving terminal locates the intra-coded frame in the second audio and video stream that is consecutive or closest in decoding timing to the last frame of the first audio and video stream by matching the frame index identifier, and uses it as the connection point for the switching.

[0013] Furthermore, in S4, the decoder maintains the decoding context, reference frame buffer, and decoding state without resetting before and after the input source is switched.

[0014] Furthermore, in S4, the receiving terminal, through the timestamp remapping module, regenerates a continuous and smooth display timestamp and decoding timestamp based on the display timestamp (PTS) and decoding timestamp (DTS) of the last frame of the first audio and video stream and the original timestamp of the intra-frame encoded frame of the second audio and video stream.

[0015] To achieve the above objectives, a second aspect of the present invention proposes a seamless signal switching system between heterogeneous broadcast television networks, comprising: a multi-link receiving module, a frame type parsing module, a switching control module, a decoding output module, a joint buffer module, and a timestamp remapping module. The multi-link receiving module is used to simultaneously maintain connections with a first network and a second network, respectively receiving a first audio / video stream and a second audio / video stream, wherein the first and second audio / video streams correspond to heterogeneous network transmission versions of the same program content. The frame type parsing module is used to extract a frame encoding type identifier from the encapsulation layer of the second audio / video stream and determine the position of the intra-frame encoded frame based on the identifier. The switching control module is used to instruct the multi-link receiving module to perform network switching when it is determined, based on the first network link measurement results. The decoding output module maintains the decoded output of the first audio / video stream while monitoring the arrival of intra-coded frames parsed from the second audio / video stream. The decoding output module, on the same decoder instance, switches the decoder input source to the data starting with the intra-coded frame detected in the second audio / video stream after decoding the current frame of the first audio / video stream. The joint buffer module buffers the frame data of the first and second audio / video streams in frame index alignment, allowing the switching control module to locate the intra-coded frame as the switching point. The timestamp remapping module, during switching, regenerates consecutive display and decoding timestamps for the switched output stream based on the timestamp of the last output frame of the first audio / video stream and the timestamp of the intra-coded frame of the second audio / video stream.

[0016] To achieve the above objectives, a third aspect of the present invention provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements a method for seamless signal switching between heterogeneous broadcast television networks according to the first aspect.

[0017] This invention discloses a seamless signal switching method and system between heterogeneous broadcast television networks. By pre-establishing a second link and receiving a second audio and video stream, the system uses the frame coding type identifier extracted from the encapsulation layer to locate the position of the intra-coded frame. When the switching conditions are met, the system maintains the output of the first audio and video stream until the intra-coded frame of the second audio and video stream arrives. After decoding the current frame, the system switches the decoder input source at the intra-coded frame, enabling the decoder to continuously decode and output without resetting or restarting. This completely eliminates the screen tearing and freezing phenomena caused by the first frame received during switching being a non-intra-coded frame, achieving truly seamless switching. Attached Figure Description

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0019] Figure 1 This is a schematic block diagram of the overall architecture of a seamless signal switching system between heterogeneous broadcast television networks according to an embodiment of the present invention;

[0020] Figure 2 This is a flowchart of a method for seamless signal switching between heterogeneous broadcast television networks according to an embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram illustrating the writing of the frame encoding type identifier at the transmitting end to the GOP alignment in a seamless signal switching method between heterogeneous broadcast television networks according to an embodiment of the present invention.

[0022] Figure 4 This is a schematic diagram of the data structure of the terminal joint frame buffer in a seamless signal handover method between heterogeneous broadcast television networks according to an embodiment of the present invention.

[0023] As shown in the figure:

[0024] 1. Multi-link receiving module; 2. Frame type parsing module; 3. Switching control module; 4. Decoding output module; 5. Joint buffer module; 6. Timestamp remapping module. Detailed Implementation

[0025] Embodiments of the present invention are described in detail below, with examples of the embodiments illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be noted that the following embodiments are illustrated using the typical scenario of a receiving terminal switching between a broadcast television network and a broadband communication network. However, those skilled in the art should understand that the essence of the method of the present invention lies in solving the problem of screen flickering or interruption during switching between heterogeneous networks caused by differences in encapsulation and protocols through frame coding type identification and alignment with intra-frame coded frames. Therefore, the scope of protection of the present invention is not limited to the network types exemplified, but is applicable to any heterogeneous network environment where the first frame received by the decoder may be a non-intra-frame coded frame due to a change in the switching source.

[0027] like Figures 1 to 4 As shown, a seamless signal switching method between heterogeneous broadcast television networks according to the present invention includes the following steps:

[0028] S1: Heterogeneous network link establishment and reception - During the process of receiving and decoding the first audio and video stream through the first network link, the receiving terminal establishes a second link with the second network and receives the second audio and video stream distributed through the second network. The first audio and video stream and the second audio and video stream correspond to heterogeneous network transmission versions of the same program content.

[0029] It should be noted that the first audio / video stream and the second audio / video stream have at least one different encoding parameter: encoding standard, group of pictures (GOP) length, resolution, bitrate, or encapsulation protocol.

[0030] S2: Frame coding type identifier extraction and intra-frame coding frame location - Extract the frame coding type identifier from the encapsulation layer of the second audio and video stream, and determine the position of each intra-frame coding frame in the second audio and video stream based on the identifier.

[0031] It should be noted that the frame encoding type identifier is written by the sender into the private descriptor of the Transport Stream (TS) packet, the extended header field of the Real-Time Transport Protocol (RTP) packet, or the Media Presentation Description (MPD) file or fragment index of the Adaptive Streaming based on Hypertext Transfer Protocol (DASH / HLS) when encapsulating the second audio and video stream.

[0032] S3: Handover Decision and Intra-coded Frame Monitoring - When it is determined that a network handover needs to be performed based on the measurement results of the first network link, the receiving terminal does not immediately interrupt the output of the first audio and video stream, but continues to decode and output the first audio and video stream. At the same time, it buffers the received second audio and video stream data in the terminal buffer and checks the frame encoding type identifier of the buffered data to determine the arrival of the intra-coded frame.

[0033] It should be noted that the terminal buffer is a joint frame buffer, which buffers the frame data of the first audio and video stream and the second audio and video stream in alignment with the frame index. Before switching the input source of the decoder to the second audio and video stream data starting with the intra-coded frame, the second audio and video stream data in the buffer before the intra-coded frame is discarded.

[0034] It should be noted that the sending end forces the audio and video streams distributed to the first network and the second network to set an aligned picture group (GOP) structure, so that the intra-coded frames in the two streams appear in time alignment, and the receiving terminal predicts the arrival time of the intra-coded frames in the second audio and video stream based on this alignment relationship.

[0035] S4: Decoder input source switching based on intra-coded frame alignment - After detecting the next intra-coded frame in the second audio / video stream, the receiving terminal switches the decoder input source to the second audio / video stream data starting from the intra-coded frame in the buffer after decoding the current frame of the first audio / video stream.

[0036] It should be noted that the sending end attaches a unified frame index identifier to the video frames distributed to the first network and the second network, and the receiving terminal locates the intra-coded frame in the second audio and video stream that is consecutive or closest in decoding timing to the last frame of the first audio and video stream by matching the frame index identifier, and uses it as the connection point for switching.

[0037] It should be noted that the decoder maintains its decoding context, reference frame buffer, and decoding state without resetting before and after the input source is switched.

[0038] It should be noted that the receiving terminal, through the timestamp remapping module 6, regenerates continuous and smooth display timestamps and decoding timestamps based on the display timestamp (PTS) and decoding timestamp (DTS) of the last frame of the first audio and video stream and the original timestamps of the intra-frame encoded frames of the second audio and video stream.

[0039] Example 1: DTMB broadcast switching to 5G-NR unicast

[0040] This embodiment describes the process of a receiving terminal switching from a DTMB terrestrial digital television broadcasting network to a 5G-NR broadband unicast network.

[0041] At the transmitting end, the same program source is encoded into two audio and video streams: the first audio and video stream is distributed through the DTMB broadcast network in AVS3 encoding, 4Mbps bitrate, and 2-second GOP length format; the second audio and video stream is distributed unicast through the user plane function of the 5G core network in H.265 encoding, 2Mbps bitrate, and 2-second GOP length format.

[0042] When encapsulating the second audio and video streams, the sending end writes the frame encoding type identifier into the private descriptor of the TS packet and adds a unified frame index identifier based on UTC time to each video frame of the two streams. At the same time, the sending end forces the two streams to set an aligned GOP structure, so that the I frames in the two streams appear simultaneously every 2 seconds.

[0043] On the receiving terminal side, the multi-link receiving module 1 maintains both the DTMB broadcast link and the 5G-NR link. The terminal plays the first audio and video stream from the DTMB network normally, and at the same time receives the second audio and video stream data through the second link. The frame type parsing module 2 extracts the frame encoding type identifier from the private descriptor of the TS packet of the second audio and video stream to determine the position of each I frame. The received second audio and video stream data is cached in the joint buffer module 5 according to the frame index alignment.

[0044] When the receiving terminal detects that the DTMB signal level has attenuated to a preset threshold, the switching control module triggers the switching process to maintain the decoding output of the first audio and video stream. At the same time, it monitors the arrival of the I-frame of the second audio and video stream in the joint buffer module 5. After detecting the next I-frame in the second audio and video stream, the decoding output module 4 switches the input source of the decoder to the second audio and video stream data starting from that I-frame after decoding the current frame of the first audio and video stream. Before the switching, the joint buffer module 5 performs a discarding process on the second audio and video stream data that has been cached before that I-frame. The decoder keeps the decoding context and reference frame buffer from being reset before and after the switching. The timestamp remapping module 6 regenerates the continuous PTS and DTS. Viewers will not perceive any screen tearing, freezing, or sound interruption during the viewing process.

[0045] Example 2: Switching from Wi-Fi multicast to 5G-NR broadcast

[0046] This embodiment describes the process of a receiving terminal switching from a Wi-Fi multicast network inside a sports stadium to an outdoor 5G-NR broadcast network.

[0047] At the transmitting end, the same live broadcast signal is encoded into two streams: the first audio and video stream is distributed via Wi-Fi network using RTP multicast, with a GOP length of 1 second; the second audio and video stream is distributed via 5G-NR broadcast, with a GOP length of 1 second.

[0048] The sending end writes the frame encoding type identifier into the extended header field of the RTP packet and appends a uniform frame index identifier to each frame of both streams.

[0049] The receiving terminal maintains both the Wi-Fi multicast link and the 5G-NR broadcast link. The frame type parsing module 2 extracts the frame encoding type identifier from the RTP extension header field to determine the I-frame position. When the terminal detects that the Wi-Fi packet loss rate rises to a preset threshold, the handover control module triggers the handover process. Similar to Embodiment 1, the terminal maintains the output of the first audio and video stream until the next I-frame of the second audio and video stream arrives. After decoding the current frame, a seamless switch of the decoder input source is performed at the I-frame, and the timestamp remapping module 6 generates continuous timestamps.

[0050] Example 3: Switching from DASH adaptive streaming to DTMB broadcast

[0051] This embodiment describes the process by which a receiving terminal switches from receiving a DASH stream from a wired IP network to a DTMB terrestrial digital television broadcasting network.

[0052] At the sending end, the first audio and video stream is encapsulated using the DASH protocol, encoded with H.264, and distributed adaptively at multiple bitrates. The second audio and video stream is encapsulated using MPEG-2-TS and broadcast via DTMB.

[0053] The sending end writes the frame encoding type identifier of each segment into the MPD file of the DASH stream, indicating whether the starting frame of the segment is an I-frame. The receiving terminal obtains the I-frame location information by parsing the MPD file. The remaining switching process is the same as the previous embodiment. The terminal maintains the output of the first audio and video stream and waits for the arrival of the second audio and video stream I-frame before performing seamless switching of the decoder input source.

[0054] like Figures 1 to 4 As shown, the present invention provides a seamless signal switching system between heterogeneous broadcast television networks, comprising: a multi-link receiving module 1, a frame type parsing module 2, a switching control module 3, a decoding output module 4, a joint buffer module 5, and a timestamp remapping module 6.

[0055] The multi-link receiving module 1 is used to maintain connections with the first network and the second network simultaneously, and to receive the first audio and video stream and the second audio and video stream respectively. The first audio and video stream and the second audio and video stream correspond to heterogeneous network transmission versions of the same program content.

[0056] The frame type parsing module 2 is used to extract the frame encoding type identifier from the encapsulation layer of the second audio and video stream, and determine the position of the intra-coded frame based on the identifier.

[0057] The switching control module 3 is used to instruct the decoding output module 4 to maintain the decoding output of the first audio and video stream when it is determined that a network switching needs to be performed based on the first network link measurement results, while monitoring the arrival of intra-coded frames parsed from the second audio and video stream.

[0058] The decoding output module 4 is used to switch the decoder input source to the data detected at the beginning of the intra-coded frame in the second audio and video stream after decoding the current frame of the first audio and video stream on the same decoder instance.

[0059] The joint buffer module 5 is used to buffer the frame data of the first audio and video stream and the second audio and video stream in alignment according to the frame index, so that the switching control module 3 can locate the intra-coded frame as the switching point.

[0060] The timestamp remapping module 6 is used to regenerate consecutive display timestamps and decoding timestamps for the output stream after switching, based on the timestamp of the last output frame of the first audio / video stream and the timestamp of the intra-frame encoded frame of the second audio / video stream.

[0061] In summary, the seamless signal switching method and system between heterogeneous broadcast television networks according to embodiments of the present invention establishes a second link in advance and receives a second audio and video stream, locates the I-frame using frame coding type identifier, maintains the output of the first audio and video stream until the I-frame of the second audio and video stream arrives when the switching conditions are met, and performs the switching of the decoder input source at the I-frame after decoding the current frame. This allows the decoder to continuously decode and output without resetting or restarting, completely eliminating the screen distortion and freezing caused by the first frame received during switching being a non-I-frame, and achieving truly seamless switching between heterogeneous networks.

[0062] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art can make various improvements and modifications to the present invention without departing from its principles, and these improvements and modifications should also be considered within the scope of protection of the present invention.

[0063] In the description of this specification, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0064] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0065] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for seamless signal switching between heterogeneous broadcast television networks, characterized in that, Includes the following steps: S1: Heterogeneous network link establishment and reception - During the process of receiving and decoding the first audio and video stream through the first network link, the receiving terminal establishes a second link with the second network and receives the second audio and video stream distributed through the second network. The first audio and video stream and the second audio and video stream correspond to heterogeneous network transmission versions of the same program content. S2: Frame coding type identifier extraction and intra-frame coding frame location - Extract the frame coding type identifier from the encapsulation layer of the second audio and video stream, and determine the position of each intra-frame coding frame in the second audio and video stream based on the identifier; S3: Handover Decision and Intra-coded Frame Monitoring - When it is determined that a network handover needs to be performed based on the measurement results of the first network link, the receiving terminal does not immediately interrupt the output of the first audio and video stream, but continues to decode and output the first audio and video stream. At the same time, it caches the received second audio and video stream data in the terminal buffer and checks the frame encoding type identifier of the cached data to determine the arrival of the intra-coded frame. S4: Decoder input source switching based on intra-coded frame alignment - After detecting the next intra-coded frame in the second audio / video stream, the receiving terminal switches the decoder input source to the second audio / video stream data starting from the intra-coded frame in the buffer after decoding the current frame of the first audio / video stream.

2. The seamless signal switching method between heterogeneous broadcast television networks according to claim 1, characterized in that, The frame encoding type identifier is written by the sending end into the private descriptor of the Transport Stream (TS) packet, the extended header field of the Real-Time Transport Protocol (RTP) packet, or the Media Presentation Description (MPD) file or fragment index of Adaptive Streaming based on Hypertext Transfer Protocol (DASH / HLS) when encapsulating the second audio and video stream.

3. The seamless signal switching method between heterogeneous broadcast television networks according to claim 1, characterized in that, The first audio / video stream and the second audio / video stream have at least one different encoding parameter: encoding standard, group of pictures (GOP) length, resolution, bitrate, or encapsulation protocol.

4. The seamless signal switching method between heterogeneous broadcast television networks according to claim 1, characterized in that, In S3, the terminal buffer is a joint frame buffer, which caches the frame data of the first audio / video stream and the second audio / video stream in alignment with the frame index; before switching the input source of the decoder to the second audio / video stream data starting from the intra-coded frame, the second audio / video stream data in the buffer before the intra-coded frame is discarded.

5. The method for seamless signal switching between heterogeneous broadcast television networks according to claim 1, characterized in that, The transmitting end forces the audio and video streams distributed to the first network and the second network to set an aligned picture group (GOP) structure, so that the intra-frame coded frames in the two streams appear in time alignment. In S3, the receiving end predicts the arrival time of the intra-frame coded frames in the second audio and video stream based on the alignment relationship.

6. The seamless signal switching method between heterogeneous broadcast television networks according to claim 1, characterized in that, The sending end attaches a unified frame index identifier to the video frames distributed to the first network and the second network. In S4, the receiving terminal locates the intra-coded frame in the second audio and video stream that is consecutive or closest in decoding timing to the last frame of the first audio and video stream by matching the frame index identifier, and uses it as the connection point for the switching.

7. The method for seamless signal switching between heterogeneous broadcast television networks according to claim 1, characterized in that, In S4, the decoder maintains the decoding context, reference frame buffer, and decoding state without resetting before and after the input source is switched.

8. The method for seamless signal switching between heterogeneous broadcast television networks according to claim 1, characterized in that, In S4, the receiving terminal uses a timestamp remapping module to regenerate a continuous and smooth display timestamp and decoding timestamp based on the display timestamp (PTS) and decoding timestamp (DTS) of the last frame of the first audio and video stream and the original timestamp of the intra-frame encoded frame of the second audio and video stream.

9. A system for seamless signal switching between heterogeneous broadcast television networks according to claims 1-8, characterized in that, include: The module comprises a multi-link receiving module (1), a frame type parsing module (2), a switching control module (3), a decoding output module (4), a joint buffer module (5), and a timestamp remapping module (6), among which, The multi-link receiving module (1) is used to maintain connections with the first network and the second network simultaneously, and to receive the first audio and video stream and the second audio and video stream respectively. The first audio and video stream and the second audio and video stream correspond to heterogeneous network transmission versions of the same program content. The frame type parsing module (2) is used to extract the frame encoding type identifier from the encapsulation layer of the second audio and video stream, and determine the position of the intra-frame encoded frame based on the identifier; The switching control module (3) is used to instruct the decoding output module (4) to maintain the decoding output of the first audio and video stream when it is determined that a network switching needs to be performed based on the first network link measurement result, while monitoring the arrival of the intra-frame encoded frames parsed from the second audio and video stream. The decoding output module (4) is used to switch the decoder input source to the data at the beginning of the intra-coded frame detected in the second audio and video stream after decoding the current frame of the first audio and video stream on the same decoder instance; The joint buffer module (5) is used to buffer the frame data of the first audio and video stream and the second audio and video stream in alignment with the frame index, so that the switching control module (3) can locate the intra-coded frame as the switching point. The timestamp remapping module (6) is used to regenerate consecutive display timestamps and decoding timestamps for the output stream after switching, based on the timestamp of the last output frame of the first audio / video stream and the timestamp of the intra-frame encoded frame of the second audio / video stream.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements a seamless signal switching method between heterogeneous broadcast television networks as described in any one of claims 1 to 8.

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