WO2008148333A1

WO2008148333A1 - System and method for processing video stream

Info

Publication number: WO2008148333A1
Application number: PCT/CN2008/071065
Authority: WO
Inventors: Xianfeng Dai
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2007-06-06
Filing date: 2008-05-23
Publication date: 2008-12-11
Also published as: CN101321275A; CN101321275B

Abstract

A system for processing video stream, includes: a program source server for decomposing the video stream of channel program into a first sub-stream and a second sub-stream, transmitting the first sub-stream to legal users, and transmitting the second sub-stream to the terminal device of the user which orders the channel program when the channel program is ordered; a terminal device for receiving the first sub-stream, applying to receiving the second sub-stream, and decoding and playing the received first sub-stream and second sub-stream. The embodiment of present invention also provides a method for processing video stream. The method includes: receiving the first sub-stream of each channel program transmitted by the program source server; requesting the program source server to transmit the second sub-stream of the channel program ordered by the user, while the first sub-stream of the channel program ordered by the user is decoded and played; decoding and playing the received the first sub-stream and the second sub-stream of the channel program ordered by the user. Thus the embodiment of present invention can realize immediate switch between direct broadcast programs, namely channel switch time of zero-delay.

Description

Video stream processing system and processing method

Technical field

The present invention relates to the field of video processing, and in particular, to a video stream processing system and processing method. Background technique

In the network to Internet Protocol (IPTV) network, channel switching time is a very important indicator, which directly affects user satisfaction. However, the prior art channel switching time is in the order of seconds. FIG. 1 is a schematic structural diagram of a video stream processing system of an abstract IPTV webcast service in the prior art, including a program source 91, a multicast copy point 92, and a terminal device 93 (eg, a set top box + a television set, or Personal computers, etc., including legitimate users and illegal users). The program source 91 is responsible for the storage of the television program and the encoding and transmission of the video stream; the multicast replication point 92 copies the corresponding television video stream from the uplink to different terminal devices 93 according to different multicast groups and their members; Apply for authorization to the externally designated device. After the identity authentication is passed, the device becomes a legitimate user. You can apply to join a multicast group (a TV channel program is usually a multicast group), and then receive the video stream of a TV channel. The device 93 decodes the received video stream and plays the same. When the channel is switched, the terminal device 93 sends an application to the external designated device to leave the original multicast group and apply to join the new multicast group. After the application is approved, the multicast replication point stops. The terminal device 93 sends the video stream of the original channel, and instead sends the video stream of the new channel program, and the terminal device 93 can receive the image of the new channel program after receiving the new channel video stream.

Sca labl e Coding is one of the modern video coding technologies, which makes the video coding process more flexible and allows multimedia information to be transmitted adaptively between networks. The problem of limited transmission bandwidth in the path of the network transmission video stream is mainly solved. In the video coding scheme, the video information stream is decomposed into a plurality of substreams, including a basic layer substream and an enhancement layer substream, wherein the basic layer The stream contains the most important basic information of the video stream. It can be decoded separately at the receiving end, and a most basic image can be obtained after decoding. The enhancement layer substream cannot be decoded separately, and must be separated from the base layer. Decode together to get a higher quality image. Currently, video coding standards that support hierarchical coding techniques are available.

MPEG-2, MPEG-4, H.263+, etc. The method makes the video stream scalable, and when the network bandwidth is small, transmits the basic layer substream, and determines whether to transmit the enhancement layer substream according to the actual network environment, so that the image quality is enhanced, thereby achieving adaptation. .

^ "fine granularity scalability (FGS) is part of the MPEG-4 coding standard, which has better flexibility than ordinary hierarchical coding techniques. There are three types of general scalable coding: Time domain can be Temporal Scalability, Spatial Scalability, SNR Scalability The rate of their enhancement layer is one or several fixed rates, and in FGS coding, the rate of the enhancement layer It can be finely adjusted according to the actual situation of the bandwidth.

The channel switching time is the time from when the remote control button is pressed to when the first frame of the video image of the next channel is displayed. In the MPEG-2 image coding mode, the video stream transmission speed is 25 frames per second, and each group of pictures (GOP) is 15 frames. The GOP consists of I frame, B frame and P frame, of which only One I frame and multiple B frames and P frames. Since only I frames can be decoded separately to display an image, and B frames and P frames cannot be decoded separately, it is necessary to rely on I frames in the same G0P to obtain an image after decoding. Therefore, the terminal device can only start displaying the video image of the channel after receiving the first I frame of the channel. If the channel switching time happens to occur after an I frame, it is necessary to wait for the entire GP transmission time to receive the next I frame, that is, the transmission time of 15 frames, and the video image of the channel can be displayed after about 600 ms.

As shown in FIG. 2, it is a schematic diagram of the composition of the channel switching time in the prior art, and the various stages in the entire channel switching process and the time they occupy are described. Starting from pressing the remote control button, they have experienced set-top box processing, sending Internet Group Management Protocol (IGMP) leaving and IGMP member reporting messages, access node IGMP message processing, aggregation node IGMP message processing, video data. The packet enters the queue, is modulated to the Digital Subscriber Line (DSL), receives the first I frame of the new channel, and decodes And display images and other links. As can be seen from the figure, the entire time is about 700ms, and most of the time is about 600ms waiting for receiving the first I frame.

In order to reduce the entire channel switching time, the existing processing system is to reduce the time interval of two adjacent I frames, that is, to reduce the size of the GOP, and increase the number of I frames, for example, reduce the GOP. In the case of 9 frames, the spacing of adjacent I frames can be reduced from 600 ms to about 360 ms.

However, although the prior art reduces the channel switching time to some extent, it is realized by increasing the number of I frames by reducing the size of the GOP, thereby sacrificing the efficiency of image coding, thereby making the image compression ratio Decrease, increasing the bandwidth occupied by the transmitted video signal. Moreover, the channel switching time calculated by the prior art does not include the time for buffering after receiving the new channel video signal, so the time is at least greater than one G0P time, that is, about 600 ms, so the prior art cannot fundamentally solve the channel. The problem of switching time is too long. Summary of the invention

Embodiments of the present invention provide a video stream processing method and processing system to implement zero-delay switching channels.

An embodiment of the present invention provides a video stream processing system, including:

a program source server, configured to decompose the video stream of the channel program into the first substream and the second substream, and send the first substream to the terminal device of the legitimate user, and when the channel program is clicked, the user of the channel program is clicked The terminal device sends the second substream;

The terminal device is configured to receive a first substream sent by the program source server, apply for receiving a second substream of the user on demand channel program, and receive the first substream and the second substream of the user on demand channel program. Decode playback.

Another aspect of the present invention provides a method for processing a video stream, including the following steps: receiving a first substream of each channel program sent by a program source server;

When receiving a request for a user to order a channel program, requesting the program source server to send the user on demand a second substream of the channel program, at the same time, decoding the first substream of the user's on-demand channel program; when receiving the second substream of the user-on-demand channel program sent by the program source server, the received user-on-demand channel program The first substream and the second substream are decoded and played.

Therefore, the processing system and processing method of the video stream of the present invention decomposes the video stream into the first substream and the second substream, and the legitimate terminal device always receives the first substream of each television channel program, so it can be in any The time simultaneously displays the basic image of each TV channel program, realizes the multi-picture display function and the picture-in-picture, and after the terminal device receives the second sub-stream of the new channel program, merges with the first sub-stream of the corresponding channel program, after decoding Obtaining a complete image of the new channel enables immediate switching between live programs, ie zero-delay channel switching time. DRAWINGS

1 is a schematic structural diagram of a video stream processing system of an abstract IPTV webcast service in the prior art;

2 is a schematic diagram showing the composition of a channel switching time in the prior art;

3 is a schematic structural diagram of a video stream processing system according to an embodiment of the present invention;

4 is a schematic structural diagram of a program source server according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of an internal implementation of a terminal device in a video stream processing system according to an embodiment of the present invention; FIG. 6 is a second internal implementation of a terminal device in a video stream processing system according to an embodiment of the present invention; FIG. Example working principle diagram of the preprocessing module;

FIG. 8 is a flowchart of a method for processing a video stream according to an embodiment of the present invention. detailed description

The technical solution of the present invention will be further described in detail below through the accompanying drawings and embodiments. The solution of the embodiment of the present invention is to realize zero-delay channel switching and multi-screen display function by using image hierarchical coding technology.

As shown in FIG. 3, it is a schematic structural diagram of a video stream processing system according to an embodiment of the present invention, including a section The source server 1 is configured to decompose the video stream of the channel program into the first substream and the second substream, and send the first substream to the legal user, and send the second substream when the channel program is clicked; The device 3 is connected to the program source server 1 through a network, and is configured to apply for receiving a second substream of the user's on-demand channel, and receive a second substream of the first substream and the user's on-demand channel for decoding and playing. The first substream and the second substream are sent out, and the second substream may be one or more substreams. The first substream occupies as small a bandwidth as possible, such as 32 kbps, which requires the terminal device to separately receive the basic image quality that the output user can accept. After the terminal device applies for authorization to become a legitimate user, the first substream of n television channels can be received, and n can be all or part of the number of TV channel programs. For multicast replication points, if a legitimate registered user is attached and a live TV program is applied, the first substream of the n TV channels can be copied and sent to each legal terminal device. The program source server also sends the first substream of the n TV channels to the multicast copy point.

When the user orders a television program of a certain channel, the terminal device applies for receiving the second substream of the channel program, that is, applying to join a multicast group related to the second substream. After receiving the second substream of the channel program, the terminal device combines the first substream and the second substream of the channel program, and decodes and displays the complete image of the channel.

When the terminal device switches channels, it only needs to leave the multicast group of the original second substream and join the second substream multicast group of the new channel program. After receiving the second substream of the new channel program, the terminal device merges with the first substream of the corresponding channel program, and obtains a complete channel complete image after decoding. The terminal device needs to switch from the second sub-stream multicast group of the original channel program to the second sub-stream of the new channel program to display the image at the terminal. However, in this handover process, the terminal device is always receiving the first substream of each TV channel program, so the terminal device can separately decode the first substream of the new channel program from the channel switching, and immediately display the new channel. The basic image of the program, thus achieving zero-delay fast channel switching. Thus the first substream can be the base layer substream of the IPTV video stream and the second substream can be the enhancement layer substream. Moreover, since the terminal device is always receiving the first substream of each television channel program, the basic image of each television channel program can be simultaneously displayed at any time, and the multi-screen display function is implemented on the television terminal, for example, at the computer terminal. The multi-screen display of the window can also implement functions such as picture-in-picture and nine-picture on the display terminal. When the user selects a program, he can also scroll through multiple screens to select his favorite program.

When the total number of TV channel programs is relatively large, such as 100, if each first sub-flow rate is 32 kbps, the total first sub-stream will occupy a larger bandwidth of about 3.2 Mbps. In order to ensure that the total first substream occupies a smaller bandwidth, the value of n can be appropriately adjusted according to the total downlink bandwidth of different end users, for example, the value range is reduced to 20-30, or the user can accept image quality. Next, the rate of the first substream of each channel program is reduced, such as from 32 kbps to 16 kbps. The n channels of the program include favorite channels and popular channels in the user's favorites, so that fast switching and browsing between these channels can be guaranteed. With the development of technology in the future, the total downlink bandwidth of end users will continue to increase. For example, when ADSL2+ reaches 4幌bps or more, the value of n can be further expanded to ensure fast switching between more channels. And browsing.

As shown in FIG. 4, it is a schematic structural diagram of a program source server of a video stream processing system according to an embodiment of the present invention, which includes a first substream generator 1 1 for generating a first independent decoding of each channel program according to a hierarchical coding manner. The substream signal 12 is configured to generate, according to the hierarchical coding manner, a second substream signal of each channel program that needs to be decoded on the basis of the first substream to obtain a complete quality image.

They use hierarchical coding to generate the first substream signal for each channel program (CH 1, CH

2 CH n ) and the second substream signal (CH 1 \ CH 2, CH n,). The second substream can be one or more substreams. In order to make the bandwidth occupied by the substream more flexible, a fine scalable video coding method can be adopted. The first sub-stream signal and the second sub-stream signal may be generated in a real-time encoding manner, or may be pre-encoded, that is, stored in the local after pre-encoding, and directly read the encoded data when being clicked to reduce the program. The burden of source server processing. In general, a channel program corresponds to a multicast group. Here, the second substream of each channel program corresponds to a different one. Multicast group. For the first substream, the first substreams (CH 1, CH 2 CH n ) of the n channels may correspond to the same multicast group, or may be respectively for n different multicast groups.

The terminal device can be implemented in two ways.

As shown in FIG. 5, it is an internal implementation of a terminal device in a video stream processing system according to an embodiment of the present invention, which includes a plurality of first hierarchical decoders 30 for respectively decoding a first substream of each received channel. a first switch (S1) 31, configured to input a second substream of the user's on-demand channel into the first hierarchical decoder of the corresponding channel, to be combined with the first substream of the user's on-demand channel to decode and play; the second switch (S2) And each of the first hierarchical decoders 30 is configured to switch to output a decoded signal of the user-on-demand channel obtained by decoding by the first hierarchical decoder.

As shown in FIG. 5, a first picture-in-picture function module 34 may be further included, and each of the first level decoders 30 is connected to the picture-in-picture picture generated according to the decoded signals of the channels output by the hierarchical decoders. The image signal; the third switch (S3) 33 is connected to the second switch 32 and the first picture-in-picture function module 34 for outputting an image signal or a picture-in-picture signal of the user's on-demand channel.

The n first hierarchical decoders 30 of the terminal device work simultaneously, and perform real-time decoding of n channel programs. For the channel X to be on-demand, the terminal device will simultaneously receive its first sub-stream CH X and the second sub-stream CH x \ The first switch (S1 ) 31 will switch CH X to X according to the selected channel number. The first hierarchical decoder -X, the first hierarchical decoder -X decodes CH X and CH X, and obtains a complete image program, which is sent to the second switch (S2) 32. S2 switches the switch to the Xth terminal according to the selected channel number, and continues to send the video signal to the third switch (S3) 33. S 3 is a play mode switch that switches between the single channel playback mode and the picture in picture playback mode. When the single channel play mode is selected, S3 will send the channel signal sent by S2 to the display to display the image program of the on-demand channel X; when the picture-in-picture playback mode is selected, S3 will send the video of the picture-in-picture function module. The signal is sent to the display to display the multi-channel picture image.

For a channel that is not on-demand, since there is no corresponding second substream signal sent to the terminal device, the corresponding first hierarchical decoder 30 can only separately decode the first substream signal and output a basic image quality signal. When these channels are not selected, these signals will not be output. but If the user requests to switch to one of the channels y, S2 will immediately switch to the yth terminal, select the output of the first grading decoder -y, send it to S3, and finally send it to the display. At the same time, the S1 input waits to receive the CH y and the second sub-stream signal, and immediately receives the signal, immediately switches to the y-th terminal, and sends the CH y statement to the first hierarchical decoder -y, so that the first The hierarchical decoder -y outputs an enhanced image quality signal to display a full quality image program on the final display.

The first picture-in-picture function module 34 always receives the video signals of n channels, and can select the corresponding channel video signal according to the user's request, perform multi-picture video fusion, and then output to the display through S3 to realize picture-in-picture and Multi-screen display function.

As shown in FIG. 6, the internal implementation of the terminal device in the video stream processing system of the embodiment of the present invention includes a pre-processing module 41, configured to select a user-on-demand channel from the first substream of the channel program. a sub-stream is sent and sent; a delay processing module 42 is configured to delay and transmit the second sub-stream of the received user-on-demand channel; and the second hierarchical decoder 43 is associated with the pre-processing module 41 and the delay processing module 42. The connection, the first substream for the user-on-demand channel transmitted from the pre-processing module 41, and the second sub-stream of the user-on-demand channel transmitted from the delay processing module 42 are combined and decoded.

As shown in FIG. 6, a second picture-in-picture function module 44 may be further included, which is connected to the pre-processing module 41 and the second level decoder 43 for decoding the first sub-stream signal and the user-on-demand channel according to each channel. The signal generates a picture-in-picture signal; the fourth switch (S4) 45 is connected to the second hierarchical decoder 43 and the second picture-in-picture function module 44 for switching the image signal or the picture-in-picture image of the output user-on-demand channel. signal.

The terminal device here shares a second hierarchical decoder 43 to implement video decoding of each channel. The pre-processing module 41 selects the CH X signal of the on-demand channel X from the n first sub-stream signals, and sends it to the second hierarchical decoder 43. The second signal CH x of the channel X is delayed and processed. The second hierarchical encoder 43 and the second hierarchical encoder 43 decode the two video signals to obtain a full quality image signal, which is sent to the fourth switch (S4) 45 of the switch. S4 is a play mode switch that switches between single channel playback mode and picture in picture playback mode. In the single channel play mode, S4 sends the video output of the second hierarchical decoder to the external display. The second picture-in-picture function module is connected to the point The video signal of the channel X is broadcasted, and the first sub-stream signal of the other channel is connected, and the multi-channel video fusion is completed after being processed, and output to the external terminal device through the S4 to realize the picture-in-picture and multi-picture display functions.

In order to ensure zero delay switching of the channel, the pre-processing module 41 needs to perform certain processing on the first sub-stream signal. The working principle is shown in FIG. 7. It is a working principle diagram of a preprocessing module according to an embodiment of the present invention. The GP of the first substream is composed of one I frame and several P frames. In this figure, the first substream is input to the preprocessing module from left to right. The preprocessing module can be abstracted into a FIFO (Fir s t in Fi rs t Out, FIFO). The length of the FIFO ensures that at least one I frame is stored in the FIFO queue. When the channel switching occurs and the first substream is used, if the preprocessing module directly sends the substream after the channel switching time to the subsequent second hierarchical decoder, it needs to transmit several P frames to obtain the first I. frame. In Figure 7, the first I frame is received after waiting for the P4 frame and the P5 frame. That is to say, a certain delay is required from the time of channel switching to display the image of the new channel on the display. In order to ensure that the new channel image is displayed immediately after the handover, the pre-processing module needs to find the first I frame forwarded by the channel switching time, that is, 10 frames in FIG. 7, and transmit the subsequent substreams from the 10 frames, in order of 10 , Pl, P2, P3, P4, P5, I. The result of this will result in a small delay t in the overall display of the program image, but since the time t is very short, it does not affect the viewing of the program. At the same time, the delay processing module in FIG. 6 needs to delay the time t of the second substream of the new channel program accordingly, and the time t between the delay module and the preprocessing module is consistent. A method of processing a module FIFO queue to ensure synchronization of the first substream and the second substream in time.

A method for processing a video stream according to an embodiment of the present invention includes:

Step 1: The program source server decomposes the video stream of the channel program into the first substream and the second substream, and sends the first substream to the legal user.

Step 2: When the user orders a TV program of one channel, the terminal device applies to receive the second substream of the user's on-demand channel; meanwhile, decodes and plays the first substream of the user's on-demand channel;

Step 3: The program source sends a second substream of the user's on-demand channel; Step 4: The terminal device decodes and plays the received first sub-stream and the second sub-stream of the user-on-demand channel, as shown in FIG. 8 , which is a flowchart of a method for processing a video stream according to an embodiment of the present invention, and the specific steps are as follows:

Step 1 01, the program source server decomposes the video stream of the channel program into the first substream and the second substream, and sends the first substream to the legal user; decomposes the video stream of the channel program into the first substream and the first The second substream, the second substream may be one or more substreams;

The first substream contains the most important basic information of the video stream, and can be decoded separately at the receiving end, and a most basic image can be obtained after decoding; the second substream cannot be decoded separately, and must be decoded together with the first substream to obtain a higher quality image;

Step 1 02: When the user clicks on the TV program of one channel, the terminal device applies to receive the second substream of the user's on-demand channel; meanwhile, the first substream of the user's on-demand channel is decoded and played;

Step 103: The program source server sends a second substream of the user's on-demand channel.

Step 1 04: The terminal device decodes the received first substream and the second substream of the user on demand channel.

Step 1 04 is implemented in a plurality of manners, for example, the terminal device decodes and plays the received first substream and the second substream of the user's on-demand channel, and specifically: the second substream of the user-on-demand channel that the terminal device will receive. And the first substream of the user-on-demand channel is combined to decode and play; or the terminal device combines the second substream of the received user-on-demand channel and the first substream of the user-on-demand channel to decode and play, and the first sub-channel of the other channel Stream decoding playback.

In another method, the terminal device selects the first substream of the user's on-demand channel from the first substream of the channel program, and combines and decodes the second substream of the user-on-demand channel after the delay processing; or the terminal device From the first substream of the channel program, the first substream of the user's on-demand channel is selected, Simultaneously decoding and playing the second substream of the user-on-demand channel after the delay processing, decoding the first substream of the other channels; in this case, selecting the first substream of the user's on-demand channel The pre-processing of the first sub-stream of the user-on-demand channel is performed, and the pre-processing may be specifically for the terminal device to find the first I-frame of the first sub-stream of the user-on-demand channel before the channel switching time, starting from the I frame. The first substream of the user's on-demand channel is transmitted. Therefore, the first substream may be a base layer substream of the IPTV video stream, and the second substream may be an enhancement layer substream, and the enhancement layer substream may be one or more substreams.

In a peer-to-peer (P2P) network, the above method is also applicable in the presence of a program source and a terminal device. Therefore, the processing system of the video stream and the processing method of the video stream of the present invention have the following beneficial effects:

1. It can realize immediate switching between IPTV live programs and realize zero delay channel switching time;

2. In the terminal to realize multi-screen display function and picture-in-picture function, users can browse multiple sets of live TV programs at the same time;

3. The program source adopts hierarchical video coding technology to decompose the TV video stream into the first substream and the second substream, which is beneficial to adopt different quality of service for the two different substreams (Qua l i ty of

Service, QoS policy, such as setting the QoS priority level of the first sub-flow higher than the QoS priority level of the second sub-flow. When the IPTV network is congested, the first sub-flow can still be preferentially passed, and the terminal user can still receive A certain quality image signal reduces the probability of the program being interrupted, thereby improving the anti-interference ability of the entire system.

It can be understood that all or part of the steps of implementing the embodiments of the present invention may be completed by a program instructing related hardware, and the program may be stored in a computer readable storage medium, the storage medium. Such as: R0M / RAM, disk, CD, etc. It should be noted that the above embodiments are only intended to illustrate the technical solutions of the present invention and are not intended to be limiting, and the present invention will be described in detail with reference to the preferred embodiments. Modifications or equivalents are made without departing from the spirit and scope of the invention.

Claims

Rights request

A processing system for a video stream, comprising:

The terminal device is configured to receive a first substream sent by the program source server, apply for receiving a second substream of the user's on-demand channel program, and receive the first substream and the second substream of the user-on-demand channel program. Decode playback.

2. The video stream processing system according to claim 1, wherein said program source server comprises:

a first substream generator, configured to generate an independently decoded first substream of each channel program according to a hierarchical coding manner;

And a second substream generator, configured to generate, according to the hierarchical coding mode, a second substream of each channel program that needs to be decoded on the basis of the first substream to obtain a complete quality image.

3. The video stream processing system according to claim 1, wherein the terminal device comprises:

a plurality of first hierarchical decoders for respectively decoding the first substream of each channel received; a first switch, configured to input a second substream of the user's on-demand channel into the first hierarchical decoder of the corresponding channel;

And a second switch, configured to switch to output a decoded signal of the user-on-demand channel obtained by decoding by the first hierarchical decoder.

The processing system of the video stream according to claim 3, wherein the terminal device further comprises:

a first picture-in-picture function module, configured for a picture-in-picture image signal generated according to a decoded signal of each channel output by each hierarchical decoder;

The third switch is configured to output an image signal or a picture-in-picture image signal of the user's on-demand channel.

5. The video stream processing system according to claim 1, wherein the terminal device comprises:

a pre-processing module, configured to select a first sub-stream of the user-on-demand channel from the first substream of the channel program and send the same;

a delay processing module, configured to delay and send the second substream of the received user-on-demand channel; the second hierarchical decoder is configured to use the first substream of the user-on-demand channel sent from the pre-processing module, and the slave The second substream of the user-on-demand channel sent by the delay processing module combines the decoded output.

The processing system of the video stream according to claim 5, wherein the terminal device further comprises:

a second picture-in-picture function module, configured to generate a picture-in-picture image signal according to the first sub-stream signal of each channel and the user-on-demand channel decoding signal;

The fourth switch is configured to switch an image signal or a picture-in-picture image signal outputting the user's on-demand channel.

7. The video stream processing system of claim 1, wherein the video stream is a network television video stream.

8. A method of processing a video stream, comprising the steps of:

Receiving a first substream of each channel program sent by the program source server;

When receiving the request of the user to order the channel program, requesting the program source server to send the second substream of the user's on-demand channel program, and simultaneously decoding the first substream of the user-on-demand channel program;

When receiving the second substream of the user-on-demand channel program sent by the program source server, the first sub-stream and the second sub-stream of the received user-on-demand channel program are decoded and played.

9. The method of processing a video stream according to claim 8, further comprising: and a second substream.

The processing method of the video stream according to claim 8, wherein the decoding and playing the first sub-stream and the second sub-stream of the received user-on-demand channel program are as follows: The second substream of the channel program and the first substream of the user's on-demand channel program are combined and decoded. Put it.

The method for processing a video stream according to claim 8, wherein: the second substream of the received user-on-demand channel program and the first substream of the user-on-demand channel program are combined and decoded, The first substream of the other channel program is decoded and played.

The method for processing a video stream according to claim 8, wherein the decoding and playing the first sub-stream and the second sub-stream of the received user-on-demand channel program are: In the stream, the first substream of the user-on-demand channel program is selected, and the second substream of the user-on-demand channel program after the delay processing is combined and decoded.

The method for processing a video stream according to claim 12, wherein the first substream of the user-on-demand channel program is selected from the first substream of the channel program, and the user-on-demand after the delay processing The second substream of the channel program is combined with the decoding and played, and the first substream of the other channel program is decoded and played.

The method for processing a video stream according to claim 12, wherein in the first substream of the channel program, the first substream of the user on demand channel program is selected, and the user is requested to order the channel. The first substream of the program is preprocessed.

The processing method of the video stream according to claim 14, wherein the performing the pre-processing is specifically: finding the first I-frame of the first sub-stream of the user-on-demand channel program before the channel switching time, After the I frame, the first substream of the subsequent user-on-demand channel program is transmitted.

16. The method of processing a video stream according to claim 8, wherein the video stream is a network to a television video stream.