CN104506868A - Video code stream transmission method, device and system - Google Patents

Abstract

The embodiment of the invention discloses a video code stream transmission method, device and system, which are used to reduce the buffering time of video images during the transmission process. The method in the embodiment of the present invention includes: the encoder performs video encoding on the video image to obtain a video code stream; the video code stream includes: a video image frame and a video delimiter, and the video delimiter is used to trigger the video code stream Send a signal forcibly, and prompt the decoder that the video image frame of the current frame ends; the encoder transmits the video code stream to the decoder.

Description

Video code stream transmission method, device and system

technical field

The invention relates to the field of data transmission, in particular to a video code stream transmission method and device.

Background technique

In the UAV high-definition real-time video transmission system, there are high requirements for delay; among them, in the whole system, the delay comes from various links such as camera image acquisition, H.264 encoding, wireless transmission, H.264 decoding and display. For a 1080P video source, 30 frames of video images per second, each frame of video images is compressed and encoded by H.264 to generate a video stream. The real-time video stream bit rate is usually 4Mbps to 8Mbps. The compressed video of each frame is sent out in the form of a stream according to the fixed packet size through the Field Programmable Gate Array FPGA (Field-Programmable Gate Array) wireless transmitting device, and the FPGA wireless receiving device After receiving the data packet and sending the video code stream to the video decoder through the Universal Serial Bus (USB, Universal Serial Bus) device, the video decoder caches the video code stream and performs framing operation by analyzing the stream structure. After a complete frame of video data is decoded and displayed immediately. During the transmission process of the entire video code stream, buffer processing is required. Therefore, the data buffer time of each link can be reduced to reduce system delay requirements.

In the H.264 identification protocol, the number of bytes per frame of the generated ES stream (original stream, elementary stream) is not fixed, and in some transmission protocols, the data must be cached to a fixed data size. The data is encapsulated and sent (that is, both sending and receiving are of fixed packet size), which will cause the situation that: when the video code stream of a video image frame cannot be divided into the same transmission packet, the video image frame The remaining video code streams will be buffered, and the data transmission device will continue to receive the video code streams, and then encapsulate and send them when the data transmission device buffers the rated data volume. Since the data belonging to the same video image frame cannot be sent continuously, it needs to wait for the data to be buffered. Therefore, at the decoding end, the frame of data received by the decoder is incomplete, and it needs to wait for the next transmission data packet to be generated before it can be received. When the data of the current video image frame is finished, the decoder cannot decode and frame the video image frame in time, and time delay will occur during video playback.

In the prior art, the method adopted in the face of this problem is that, in the video image frame of the previous output data packet, when there is remaining data in the cache state, the remaining data is filled with data, and the remaining data is Encapsulate into a transmission data packet of a rated size, so that the video image frames of each frame can be sent out continuously without buffering and waiting.

However, this method of data filling will generate a large amount of redundant and invalid data, the processing is time-consuming and inefficient, and it will also cause a waste of transmission bandwidth.

Contents of the invention

Embodiments of the present invention provide a video code stream transmission method, device and system, which are used to reduce the buffering time of the video code stream during transmission.

The video code stream transmission method provided by the embodiment of the present invention includes:

The encoder performs video encoding on the video image to obtain a video code stream; the video code stream includes: a video image frame and a video delimiter, and the video delimiter is used to trigger a mandatory sending signal to the video code stream, and prompts The end of the video image frame of the current frame of the decoder;

The encoder transmits the video code stream to the decoder.

Another video code stream transmission method provided by an embodiment of the present invention includes:

The data transmission device receives a video code stream, and the video code stream includes: a video image frame and a video delimiter, and the video delimiter is used to trigger a mandatory sending signal to the video code stream, and to prompt the decoder for the video of the current frame image frame end;

The data transmission device caches the video code stream; if the video delimiter is identified in the received video code stream, the forced sending signal is triggered, and the currently cached video code stream is Encapsulated into a data packet;

The data transmission device sends the video code stream encapsulated into the data packet to the decoder.

The video encoder provided by the embodiment of the present invention includes:

The video encoding unit is used to perform video encoding on the video image to obtain a video code stream; the video code stream includes: a video image frame and a video delimiter, and the video delimiter is used to trigger the mandatory sending of the video code stream signal, and prompt the decoder to end the video image frame of the current frame;

a transmission unit, configured to transmit the video code stream to the decoder.

The data transmission device provided by the embodiment of the present invention includes:

The code stream receiving unit is used to receive the video code stream, and the video code stream includes: a video image frame and a video delimiter, and the video delimiter is used to trigger the mandatory sending signal of the video code stream, and prompt the decoder The video image frame of the current frame ends;

A data encapsulation unit, configured to cache the video code stream, if the video delimiter is identified in the received video code stream, trigger the mandatory sending signal, and convert the currently cached video code stream to The stream is encapsulated into a packet;

The code stream transmission unit is configured to send the video code stream encapsulated into the data packet to the decoder.

The video code stream transmission system provided by the embodiment of the present invention includes:

Encoders, transmitters, receivers and decoders;

The encoder is used to perform video encoding on the video image to obtain a video code stream; the video code stream includes: a video image frame and a video delimiter, and the video delimiter is used to trigger a mandatory sending signal to the video code stream , and remind the decoder that the video image frame of the current frame is over; the encoder transmits the video code stream to the sending device;

The sending device transmits the video code stream to the receiving device through a wireless channel;

The receiving device caches the video code stream, and if the video delimiter is recognized in the received video code stream, triggers the forced sending signal, and encapsulates the currently cached video code stream into a data packet, and send the video code stream encapsulated into the data packet to the decoder.

It can be seen from the above technical solutions that the embodiments of the present invention have the following advantages:

In the embodiment of the present invention, the encoder sets the video delimiter after the end of a video image frame when performing the video code stream, so that during the transmission of the video code stream, when the video delimiter is recognized, the video delimiter is forced to The data in the cache is encapsulated and sent, so that a frame of video image frames can be sent continuously without waiting in the cache process, which reduces the time delay of the video code stream in the transmission process; at the same time, the video delimiter in the embodiment of the present invention It is set according to the video codec standard, and can be recognized by the decoder, so that the decoder can also recognize the end of the video image frame of the current frame, without destroying the data structure of the existing video stream, and without additional decoding The device is improved and used in a wide range.

Description of drawings

Fig. 1 is a schematic flow chart of the video code stream transmission method in the embodiment of the present invention;

Fig. 2 is a schematic diagram of the data structure of the video code stream in the embodiment of the present invention;

FIG. 3 is another schematic flowchart of a video code stream transmission method in an embodiment of the present invention;

Fig. 4 is a schematic diagram of the data structure of the access unit delimiter in the embodiment of the present invention;

FIG. 5 is another schematic flowchart of a video code stream transmission method in an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of an encoder in an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a data transmission device in an embodiment of the present invention;

FIG. 8 is a schematic structural diagram of a video code stream transmission system in an embodiment of the present invention.

Detailed ways

Embodiments of the present invention provide a video code stream transmission method, device and system, which are used to reduce the buffering time of the video code stream during transmission.

Referring to Fig. 1, an embodiment of the video code stream transmission method in the embodiment of the present invention includes:

101. The encoder performs video encoding on the video image;

The encoder performs video encoding on the video image to obtain a video code stream; the video code stream includes: a video image frame and a video delimiter, and the video delimiter is used to trigger a mandatory sending signal to the video code stream, and prompts The end of the video image frame for the current frame of the decoder.

Wherein, in the data structure of the video code stream, the video delimiter is located after the first video image frame.

The forced sending signal is used to instruct the USB device to transmit small packets of data.

Further, the video delimiter may also be located after each video image frame. For details, refer to FIG. 2, which is a schematic diagram of the data structure of the video code stream, wherein, in the video code stream H.264 standard, the data packet The first network abstraction layer unit type (NALU, Network Abstraction LayerUnit) is a sequence parameter set (SPS, sequence parameter set), the second NALU is a picture parameter set (PPS, picture parameter set), and the third NALU is instant decoding The device refreshes (IDR, instantaneous decoding refresh) frame, that is, the first video image frame, and the next NALU is the prediction (P, Predictive Frame) frame. In the data structure of the H.264 standard, video image frames include: IDR frame and P frame; unit delimiter), so that during the transmission of the video stream on the USB device, at the end of each video image frame, regardless of whether the cache requirements of the data volume are met, the current cached data will be encapsulated and sent, thereby reducing the video image frame of the same frame cache time.

Optionally, the encoding object of the encoder may be a video image in a luminance and chrominance (YUV, LuminanceChrominance) format. After the encoding is completed, the format of the obtained video code stream can be the original code stream (ES, elementary stream) format.

102. The encoder transmits the video code stream to the decoder.

The encoder transmits the video code stream to the decoder, wherein the video code stream passes through the USB device during transmission to the decoder.

In the existing USB device transmission standard, there is a mechanism for forcing the transmission of short data packets, which is used to send all the remaining data transmitted to the end in the data transmission device; specifically, when the data transmission device triggers the mechanism in the When the signal is forced to be sent, the remaining data in the buffer of the data transmission device can be encapsulated and sent without buffering enough rated data volume.

Specifically, the forced sending signal may be a PKTEND signal; when the data transmission device transmits the video code stream in the embodiment of the present invention, when the video delimiter is recognized, the PKTEND signal is triggered to force the buffered The data (less than 512bytes) is encapsulated and sent.

At the same time, since the video code stream sent by the encoder must be transmitted to the decoder for decoding, the video delimiter used to trigger the PKTEND signal must be recognized by the decoder, otherwise, the data structure of the video code stream will be destroyed, making decoding The device cannot recognize the current video stream. In the embodiment of the present invention, AUD is used as the delimiter indicating the end of the video image frame and the trigger flag of the PKTEND signal. Since AUD is in the sentence format specified in the H.264 standard, it can be recognized by the decoder.

In the embodiment of the present invention, the mechanism of forced transmission of short data packets is cleverly used. When the encoder is performing video code streams, a video separator is set after the end of a frame of video image frames, so that the video code streams are transmitted on the USB device. During the transmission process, when the video delimiter is recognized, the data in the cache is forced to be encapsulated and sent, so that a frame of video image frames can be sent continuously without waiting in the cache process, reducing the video stream during transmission. time delay; at the same time, the video delimiter in the embodiment of the present invention is set according to the video codec standard, and can be recognized by the decoder, so that the decoder can also recognize the end of the video image frame of the current frame, and will not The data structure of the existing video code stream is destroyed, no additional improvement of the decoder is required, and the application range is wide.

The specific transmission process of the above-mentioned video code stream transmission method is described below. Please refer to FIG. 3. Another embodiment of the video code stream transmission method in the embodiment of the present invention includes:

301. The encoder receives the video image sent by the camera device;

Specifically, the format of the video image may be a YUV format.

302. The encoder performs video encoding on the video image;

The encoder performs video encoding on the video image to obtain a video code stream; the video code stream includes: a video image frame and a video delimiter, and the video delimiter is used for triggering a forced video code stream during USB device transmission. Send a signal and notify the decoder that the video image frame of the current frame is over.

Specifically, the format of the video code stream may be ES format. The video delimiter is AUD, and please refer to FIG. 4 for the data definition format of AUD.

303. The encoder transmits the video code stream to the FPGA sending device;

304. The FPGA sending device transmits the video code stream to the FPGA receiving device through a wireless channel;

Specifically, after the FPGA sending device receives the video code stream sent by the encoder, it needs to perform channel coding on the video code stream, and encapsulate the video code stream into data for wireless channel transmission, but does not change the video code stream in the video code stream. Data structure of video image frames and video delimiters.

Optionally, the process of the FPGA sending device encapsulating and sending the video code stream may be:

If the video code stream is received, the video code stream is cached; if the data volume of the cached video code stream reaches the transmission threshold, the currently cached video code stream is encapsulated into a data packet; if If the video delimiter is identified in the received video code stream, the currently buffered video code stream is encapsulated into a data packet; the FPGA sending device sends the encapsulated data packet to the decoder through a wireless channel. The video code stream of the package.

305. The FPGA receiving device transmits the video code stream to the decoder through a USB device;

Specifically, when the FPGA receiving device receives the video code stream, it caches the video code stream; if the data volume of the cached video code stream reaches the transmission threshold, the currently cached video code stream is encapsulated into A data packet; if the video delimiter is identified in the received video code stream, the PKTEND signal of the trigger USB is valid, and the currently cached video code stream is encapsulated into a data packet; the FPGA sending device passes The USB device sends the video code stream encapsulated into the data packet to the decoder.

306. The decoder decodes and frames the data packet.

The application scenarios in the embodiments of the present invention are described above using only some examples, and it can be understood that in actual applications, there may be more application scenarios, which are not specifically limited here.

The video code stream transmission method in the embodiment of the present invention is described below from the data transmission device side. Please refer to FIG. 5. Another embodiment of the video code stream transmission method in the embodiment of the present invention includes:

501. The data transmission device receives a video code stream;

The data transmission device receives a video code stream, and the video code stream includes: a video image frame and a video delimiter, and the video delimiter is used to trigger a mandatory sending signal to the video code stream, and to prompt the decoder for the video of the current frame Image frame ends.

Optionally, the data transmission device in the embodiment of the present invention may be an FPGA receiving device, may also be an FPGA sending device, or may be other physical devices, as long as the intermediate link of the video stream transmission passes through the USB device.

Specifically, the forced sending signal is used to instruct the USB device to transmit small packets of data.

When the data transmission device in the embodiment of the present invention is an FPGA receiving device, the FPGA receiving device receives the video code stream sent by the FPGA sending device through the wireless channel.

Specifically, the format of the video code stream may be ES format. The video separator may be AUD. The forced sending signal may be a PKTEND signal. The video image frames include: IDR frames and P frames.

502. The data transmission device performs data encapsulation on the video code stream;

The data transmission device caches the video code stream, and if the video delimiter is identified in the received video code stream, encapsulates the currently buffered video code stream into a data packet.

Optionally, if the data volume of the cached video code stream reaches a transmission threshold, the currently cached video code stream is encapsulated into a data packet.

In the embodiment of the present invention, when a video delimiter is identified in the received video code stream, the forced sending signal of the USB device interfaced with the data transmission device is triggered, and the USB device that does not currently reach the transmission threshold is forced to The video stream is encapsulated for data.

503. The data transmission device sends the video code stream encapsulated into the data packet to the decoder.

Specifically, the data transmission device may also send the video code stream encapsulated into the data packet to the decoder through the USB device.

In the embodiment of the present invention, when the data transmission device recognizes the video delimiter, it will force the data in the buffer to be encapsulated and sent, so that a frame of video image frames can be sent continuously without waiting in the buffer process, reducing the video stream delay in the transmission process; meanwhile, the video delimiter in the embodiment of the present invention is set according to the video codec standard, and can be recognized by the decoder side, so that the decoder can also recognize the video image of the current frame The end of the frame will not destroy the data structure of the existing video code stream, no additional improvement to the decoder is required, and the application range is wide.

The following describes an embodiment of the encoder of the present invention for implementing the above-mentioned video code stream transmission method. Please refer to FIG. 6 for its logical structure. An embodiment of the encoder in the embodiment of the present invention includes:

The video encoding unit 601 is configured to perform video encoding on the video image to obtain a video code stream; the video code stream includes: a video image frame and a video delimiter, and the video delimiter is used to trigger the compulsory video code stream Send a signal and prompt the decoder that the video image frame of the current frame is over;

The transmission unit 602 is configured to transmit the video code stream to the decoder; wherein, the video code stream passes through the USB device during transmission to the decoder.

The transmission unit 602 is further configured to: pass the USB device during the transmission of the video code stream to the decoder. Further, the transmission unit can transmit the video code stream to a field programmable gate array FPGA sending device, and the FPGA sending device transmits the video code stream to the FPGA receiving device through a wireless channel, and the FPGA receiving device transmits the video code stream to the FPGA receiving device. The video code stream is transmitted to the decoder through the USB device. The forced sending signal is used to instruct the FPGA receiving device to send the currently buffered video code stream to the decoder.

Further, the video image frame includes: instantaneous decoding refresh IDR frame and predicted P frame;

The video delimiter includes: an access unit delimiter AUD;

The forced sending signal includes: PKTEND signal;

The format of the video image is brightness and chroma YUV format;

The format of the video code stream is the original code stream ES format.

The following describes an embodiment of the data transmission device of the present invention for implementing the above-mentioned video code stream transmission method. Please refer to FIG. 7 for its logical structure. An embodiment of the data transmission device in the embodiment of the present invention includes:

The code stream receiving unit 701 is configured to receive a video code stream, the video code stream includes: a video image frame and a video delimiter, and the video delimiter is used to trigger a mandatory sending signal to the video code stream, and prompt decoding The end of the video image frame of the current frame of the device;

The data encapsulation unit 702 is configured to cache the video code stream, and if the video delimiter is identified in the received video code stream, encapsulate the currently buffered video code stream into a data packet ; Optionally, if the data volume of the cached video code stream reaches the transmission threshold, then encapsulate the currently cached video code stream into a data packet;

A code stream transmission unit 703, configured to send the video code stream encapsulated into the data packet to the decoder. Further, the code stream transmission unit 703 is specifically configured to send the video code stream encapsulated into the data packet to the decoder through the USB device.

Further, the video image frame includes: instantaneous decoding refresh IDR frame and predicted P frame;

The video delimiter includes: an access unit delimiter AUD;

The forced sending signal includes: PKTEND signal;

The format of the video code stream is the original code stream ES format.

The following describes an embodiment of the video code stream transmission system of the present invention for implementing the above video code stream transmission method. Please refer to FIG. 8. An embodiment of the video code stream transmission system in the embodiment of the present invention includes:

Encoder 801, sending device 802, receiving device 803 and decoder 804;

The encoder 801 is used to perform video encoding on the video image to obtain a video code stream; the video code stream includes: a video image frame and a video delimiter, and the video delimiter is used to trigger the mandatory Sending a signal and prompting the decoder that the video image frame of the current frame is over; the encoder transmits the video code stream to the sending device;

The sending device 802 transmits the video code stream to the receiving device 803 through a wireless channel;

The receiving device 803 caches the video code stream, and if the video delimiter is identified in the received video code stream, encapsulates the currently buffered video code stream into a data packet; and Send the video code stream encapsulated into the data packet to the decoder 804 .

Optionally, the sending device 802 may be an FPGA sending device, and the receiving device 803 may be an FPGA receiving device.

For the specific operation method of the above-mentioned device and system, reference may be made to the description of the above-mentioned method embodiment, and details are not repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or May be integrated into another system, or some features may be ignored, or not implemented. In another point, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of devices or units may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, each unit may exist separately physically, or two or more units may be integrated into one unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

If the integrated unit is realized in the form of a software function unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the essence of the technical solution of the present invention or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium , including several instructions to make a computer device (which may be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-OnlyMemory), random access memory (RAM, Random Access Memory), magnetic disk or optical disc and other media that can store program codes.

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Anyone skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present invention. Should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (28)

1. a video code flow transmission method, is characterized in that, comprising:

Encoder carries out Video coding to video image, obtains video code flow; Described video code flow comprises: video frame image and video separator, and described video separator sends signal for triggering to the pressure of described video code flow, and points out the video image frame end of decoder present frame;

Described encoder is to video code flow described in described decoder transfers.

2. method according to claim 1, is characterized in that, described method also comprises:

Described video code flow in the process of described decoder transfers through general-purpose serial bus USB equipment.

3. method according to claim 2, is characterized in that, described pressure sends signal and is used to indicate USB device transmission parcel data.

4. method according to claim 1, is characterized in that,

Described video frame image comprises: instantaneous decoding refresh every IDR frame and prediction P frame;

Described video separator comprises: access unit delimiter AUD;

Described pressure sends signal and comprises: PKTEND signal.

5. method according to claim 1, is characterized in that,

The form of described video image is brightness and colourity yuv format;

The form of described video code flow is source code flow ES form.

6. method according to claim 1, it is characterized in that, described encoder, to video code flow described in described decoder transfers, comprising:

Described video code flow is transferred to on-site programmable gate array FPGA dispensing device by described encoder, by wireless channel, described video code flow is transferred to FPGA receiving system by described FPGA dispensing device, by USB device, described video code flow is transferred to described decoder by described FPGA receiving system.

7. method according to claim 6, is characterized in that, described pressure sends signal and is used to indicate described FPGA receiving system the video code flow of current cache is sent to described decoder.

8. a video code flow transmission method, is characterized in that, comprising:

Data transmission device receiver, video code stream, described video code flow comprises: video frame image and video separator, and described video separator sends signal for triggering to the pressure of described video code flow, and points out the video image frame end of decoder present frame;

Described data transmission device carries out buffer memory to described video code flow; If recognize described video separator in the described video code flow received, then trigger described pressure and send signal, the described video code flow of current cache is packaged into a packet;

Described data transmission device sends the video code flow being packaged into described packet to described decoder.

9. method according to claim 8, it is characterized in that, described data transmission device comprises after carrying out buffer memory to described video code flow:

If the data volume of the described video code flow of buffer memory reaches propagation threshold, then the described video code flow of current cache is packaged into a packet.

10. method according to claim 8, is characterized in that, described data transmission device sends the video code flow being packaged into described packet to described decoder, comprising:

Described data transmission device sends the video code flow being packaged into described packet to described decoder by USB device.

11. methods according to claim 10, is characterized in that, described pressure sends signal and is used to indicate described USB device transmission parcel data.

12. methods according to claim 8, is characterized in that,

Described video frame image comprises: every IDR frame and P frame;

Described video separator comprises: AUD;

Described pressure sends signal and comprises: PKTEND signal.

13. methods according to claim 8, is characterized in that,

The form of described video code flow is source code flow ES form.

14. methods according to claim 8, is characterized in that,

Described data transmission device comprises: FPGA receiving system;

Described data transmission device receiver, video code stream, comprising:

Described FPGA receiving system receives the video code flow that FPGA dispensing device is sent by wireless channel.

15. 1 kinds of encoders, is characterized in that, comprising:

Video encoding unit, for carrying out Video coding to video image, obtains video code flow; Described video code flow comprises: video frame image and video separator, and described video separator sends signal for triggering to the pressure of described video code flow, and points out the video image frame end of decoder present frame;

Transmission unit, for video code flow described in described decoder transfers.

16. encoders according to claim 15, is characterized in that, described transmission unit also for:

Described video code flow in the process of described decoder transfers through USB device.

17., according to encoder described in claim 16, is characterized in that, described pressure sends signal and is used to indicate USB device transmission parcel data.

18., according to encoder described in claim 15, is characterized in that,

Described video frame image comprises: instantaneous decoding refresh every IDR frame and prediction P frame;

Described video separator comprises: access unit delimiter AUD;

Described pressure sends signal and comprises: PKTEND signal.

19., according to encoder described in claim 15, is characterized in that,

The form of described video image is brightness and colourity yuv format;

The form of described video code flow is source code flow ES form.

20., according to encoder described in claim 15, is characterized in that, described transmission unit also for:

Described video code flow is transferred to on-site programmable gate array FPGA dispensing device, by wireless channel, described video code flow is transferred to FPGA receiving system by described FPGA dispensing device, by described USB device, described video code flow is transferred to described decoder by described FPGA receiving system.

21., according to encoder described in claim 20, is characterized in that, described pressure transmission signal is used to indicate described FPGA receiving system and the video code flow of current cache is sent to described decoder.

22. 1 kinds of data transmission devices, is characterized in that, comprising:

Code stream receiving element, for receiver, video code stream, described video code flow comprises: video frame image and video separator, and described video separator sends signal for triggering to the pressure of described video code flow, and points out the video image frame end of decoder present frame;

Data packaging unit, for carrying out buffer memory to described video code flow, if recognize described video separator in the described video code flow received, then triggers described pressure and sends signal, the described video code flow of current cache is packaged into a packet;

Bit stream unit, for sending the video code flow being packaged into described packet to described decoder.

23., according to data transmission device described in claim 22, is characterized in that, described data packaging unit also for:

If the data volume of the described video code flow of buffer memory reaches propagation threshold, then the described video code flow of current cache is packaged into a packet.

24., according to data transmission device described in claim 22, is characterized in that, described bit stream unit is specifically for sending the video code flow being packaged into described packet to described decoder by USB device.

25., according to data transmission device described in claim 24, is characterized in that,

Described pressure sends signal and is used to indicate described USB device transmission parcel data.

26., according to data transmission device described in claim 22, is characterized in that,

Described video frame image comprises: every IDR frame and P frame;

Described video separator comprises: AUD;

Described pressure sends signal and comprises: PKTEND signal.

27., according to data transmission device described in claim 22, is characterized in that,

The form of described video code flow is source code flow ES form.

28. 1 kinds of video code flow transmission systems, is characterized in that, comprising:

Encoder, dispensing device, receiving system and decoder;

Described encoder is used for carrying out Video coding to video image, obtains video code flow; Described video code flow comprises: video frame image and video separator, and described video separator sends signal for triggering to the pressure of described video code flow, and points out the video image frame end of decoder present frame; Described video code flow is transferred to described dispensing device by described encoder;

Described video code flow is transferred to described receiving system by wireless channel by described dispensing device;

Described receiving system carries out buffer memory to described video code flow, if recognize described video separator in the described video code flow received, then trigger described pressure and send signal, the described video code flow of current cache is packaged into a packet, and sends the video code flow being packaged into described packet to described decoder.