CN1976439A - Method for realizing picture-in-picture playing function in IPIV - Google Patents

Abstract

The invention discloses a method for realizing the picture-in-picture playback function in IPTV, which is built on the existing CDN-based video-on-demand (VOD) system of IPTV, including the operation control and picture There are three parts: the production of special video for China Picture and the application of local client. Different from the traditional TV system, the video played by the picture-in-picture function of the present invention is not a multicast real-time live program, but a dedicated video stream from the on-demand system that has been encoded and compressed, and the picture is suitable for the application of picture-in-picture. The invention not only enables users to enjoy the picture-in-picture service through IPTV, but also occupies less bandwidth, directly reduces the frequency of user channel switching, and also greatly reduces the time delay of channel switching, avoiding the delay caused by the prolongation of switching. The quality of experience brought about is reduced, and network resources and expenses are saved, which is conducive to the promotion and application of IPTV.

Description

A method for realizing picture-in-picture playback function in IPTV

technical field

The invention relates to a video-on-demand (VOD) service in IPTV, in particular to a method for playing and previewing other live channel programs in the form of a picture-in-picture based on a video-on-demand (VOD) system in the IPTV.

Background technique

IPTV, that is, a TV system based on IP network, is based on the service of user experience as the core, with "TV + set-top box" as the main terminal equipment, and provides broadband users with an interactive TV experience through the broadband IP network of telecom operators , is a broadband value-added service that provides multimedia services.

Compared with the traditional cable TV network, IPTV's bearer network—IP network has an absolute advantage in interactivity, so IPTV clients can enjoy all services on the Internet very conveniently. At the same time, due to the "best effort" inherent feature of the IP network, how to ensure the QoS of IPTV so that the user's quality of experience is at least not inferior to that of traditional wired wires has become a very critical issue.

Live video, time-shifted TV and video on demand are the three key services of IPTV. It is generally believed in the existing technology that multicast (Multicast) technology should be used for large-scale commercial IPTV live video services, while video on demand and time-shifted TV services are suitable for building content distribution networks through CDN technology, and pushing programs to edge servers close to users , to reduce the bandwidth required for a large number of unicast services. But at the present stage, the widely used MPEG4 standard is used to encode the video stream, and the data rate of a set of standard-definition programs can reach 1.2-1.5 Mbps, while that of high-definition programs can reach more than 3 Mbps. It can be seen that for the broadband access methods commonly used in China at present, the bandwidth is stretched. The problem of bandwidth is undoubtedly an important reason for restricting the large-scale promotion of IPTV at present.

Considering the current types of domestic access networks and the general situation of digital communication usage by general broadband users, it seems to be a better choice to push one or two sets of programs at the same time, but it will cause the following problems: the channel switching of IPTV live broadcast service is due to It needs to be done between two multicast groups, and the delay is much longer compared to traditional TV systems that always push all channels to the user terminal through the coaxial cable. For the mass users who have been accustomed to the time delay of traditional TV channel switching for many years, the time delay of IPTV is obviously unacceptable. For this reason, the Chinese patent application with the publication number CN1713720A applied by Shanghai Jiao Tong University proposes a method for reducing channel switching delay by simultaneously pushing multiple programs, but this method still does not take into account the reality of bandwidth. Therefore, in IPTV, a service in which user experience quality is extremely important, the problem of channel switching delay still needs to be solved urgently.

In addition, the picture-in-picture function in traditional TV systems has always been deeply loved by people. This technology not only enables users to browse content being played by other channels without switching channels, but also reduces the overhead caused by frequent channel switching. Through the picture-in-picture function, it is of great significance to solve the delay problem of IPTV channel switching and the problem of large network and local resource overhead. At the same time, due to the advanced nature and practicality of this function, it is imperative to realize this picture-in-picture function in IPTV.

In a traditional TV system, all channel programs are pushed to the client, and to realize the picture-in-picture function, it is only necessary to play another channel in the sub-picture. For IPTV, it is impossible to meet such conditions in the current situation. If a multicast channel is simply pushed for the sub-picture to realize the picture-in-picture function, it is obviously impossible to achieve the purpose of reducing channel switching time and resource overhead. . Therefore, how to implement the picture-in-picture function in IPTV, and based on this function to solve the bandwidth problem and the time delay problem of switching channels, is a subject before us. The breakthrough of this subject will undoubtedly be able to effectively promote the popularization, promotion and development of IPTV.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies in the prior art, provide a kind of video on demand (VOD) system based on existing CDN structure, adopt the mode similar to ordering, preview other live channel programs with the form of picture-in-picture, thereby in IPTV The method for realizing the picture-in-picture playback function also provides a way for solving the bandwidth problem and the prolongation problem when switching channels.

The purpose of the present invention is achieved through the following technical solutions:

A kind of method that realizes picture-in-picture playing function in IPTV provided by the present invention, comprises the following steps:

a. The live program source server supplies live programs to users in the form of multicast, and at the same time transmits and stores the live programs of all channels to the on-demand program source server in real time;

b. Make special video for picture-in-picture;

c. Slice the dedicated video for picture-in-picture, and distribute it to the edge server through the content distribution network according to the rules of the video-on-demand system;

d. After the local user terminal activates the picture-in-picture function, it sends a signal to the video-on-demand system to order the special video of the picture-in-picture. Painting dedicated video;

e. The local client performs decoding and decompression processing on the received picture-in-picture dedicated video, and then plays it on the picture-in-picture sub-window of the TV screen.

The making of the picture-in-picture special video of the present invention can take following further measures: its making step is

b-1. For the programs of each live channel transmitted to the on-demand program source server, at a certain moment, the video segment of the previous period T time calculated from the current moment of each channel is intercepted;

b-2. Connect all the intercepted video segments end-to-end according to the order of channels to form a new video stream;

b-3. According to the needs of the picture-in-picture application function, perform video encoding and compression processing on the new video stream generated by interception, so as to obtain the special video for picture-in-picture;

b-4. According to the design requirements of the VOD system, add the relevant information needed as an on-demand program to the produced picture-in-picture special video, and store the picture-in-picture special video as an on-demand program in the server after completion.

The present invention first transmits and stores the live program in the source server of the on-demand program, and periodically intercepts a short period of video segments from the latest live program channels and cyclically connects them to form a video stream, and then aims at the special application of picture-in-picture (Small resolution, low quality requirements), encoding and compressing the intercepted video stream, so as to periodically produce a dedicated picture-in-picture video stream, so that it occupies as little bandwidth as possible. For this reason, the present invention is different from traditional television system, and the video played by its picture-in-picture function is not a real-time live broadcast program of multicast, but a special-purpose video that is suitable for the application of picture-in-picture and comes from an on-demand system through encoding and compression processing. stream, thus greatly reducing the delay of channel switching.

At present, in order to meet the needs of completed live program on-demand and time-shifted TV services in IPTV, the on-demand program source server needs to obtain real-time live program videos from the live program source, and slice these videos for distribution to the edge server. The transmission and playback of the picture-in-picture special-purpose video of the present invention is also as a kind of business based on the video-on-demand (VOD) system, so the special-purpose video of the picture-in-picture that is produced is sliced according to the rules of the video-on-demand (VOD) system, and then distributed to edge servers. In this way, while maintaining the existing main screen channel (multicast live channel or unicast on-demand channel), the local client can enable the user to browse the preview video of each channel in real time in the form of picture-in-picture on the sub-screen .

Since the special video for picture-in-picture in the present invention is generated according to the cycle, the edge server in the present invention transmits the special video for picture-in-picture to the user, periodically transmits it to the local user according to the generation cycle of the special video for picture-in-picture terminal; after accumulating several cycles of dedicated video in picture-in-picture, delete the earlier video.

The picture-in-picture special video of the present invention is produced by the picture-in-picture video production module, which is placed on the server side and includes the following three submodules:

The video cutting and integration module is used to cut the video stream of the arriving live program at intervals of T, and connect the cut video clips end to end into a new video clip;

An encoding and compression module is used to encode and compress the video clips processed by the video cutting and integration module;

The relevant information adding module is used for adding information to the video stream processed by the video cutting, integrating module and encoding and compressing module as an on-demand program.

In addition, it can be considered that the special video program for picture-in-picture is a popular program requested by users. For this reason, in the process of distributing the special video for picture-in-picture in the present invention to the edge server, special distribution rules and priorities for picture-in-picture can be added. Videos are prioritized for distribution.

When the picture-in-picture special video is played at the local client end, the present invention is played through the picture-in-picture function control and playback module, and the module includes a picture-in-picture function control module and a picture-in-picture video playback module, wherein:

The picture-in-picture function control module is used to receive instructions from the user about picture-in-picture related functions, and send instructions to the picture-in-picture video playback module to turn on, switch channels, and turn off picture-in-picture functions;

The picture-in-picture video playback module is used to receive instruction signals from the control module and perform corresponding operations, send an on-demand request to the edge server, and receive and play video data transmitted from the edge server.

The present invention has the following beneficial effects:

(1) Utilize the existing video-on-demand (VOD) system based on the CDN structure, and adopt a method similar to on-demand to realize the picture-in-picture function of IPTV, which not only makes full use of the existing network technology and resources, but also occupies less bandwidth , contribute to the promotion and application of IPTV.

(2) The frequency of user channel switching is directly reduced, and at the same time, the time delay of channel switching is also greatly reduced, avoiding the degradation of experience quality brought to users due to the prolongation of switching time. In addition, network resources and overhead are saved.

(3) Through the picture-in-picture function, the user can obtain the broadcasting screens of other channels earlier than the current time, so as to achieve the purpose of obtaining the approximate broadcasting content of each channel at that time.

Description of drawings

The present invention will be described in further detail below in conjunction with embodiment and accompanying drawing:

Fig. 1 is a schematic diagram of the operation process of each node in the server end and the transmission network in the embodiment of the present invention;

Fig. 2 is a schematic diagram of the structural composition and production principle of the picture-in-picture video production module in the embodiment of the present invention;

Fig. 3 is a schematic diagram of the application process of the local client in the embodiment of the present invention;

Fig. 4 is a block diagram of the operation flow of the embodiment of the present invention.

Detailed ways

Fig. 1～Fig. 4 shows the embodiment of the present invention, builds on the existing video on demand (VOD) system of IPTV, comprises the operation control of each node in the server end and transmission network, the making of special video in picture-in-picture and local There are three parts to the client application.

(1) The operation control of the server and each node in the transmission network

As shown in Figure 1, the specific steps of the operation control of the server and each node in the transmission network are as follows:

a. The live program source server supplies live programs to users in the form of multicast, and at the same time transmits and stores the live programs of all channels to the on-demand program source server for processing. Its purpose is: 1. Make live programs into on-demand programs, provide On-demand live programs or business content using the time-shift function; 2. Make live programs into picture-in-picture videos and provide business content with picture-in-picture functions;

b. By setting the picture-in-picture video production module on the server side, make a special picture-in-picture video;

c. In order to meet the needs of completed live program on-demand and time-shifted TV services, the on-demand program source server needs to obtain real-time live program videos from the live program source, and slice these videos for distribution to the edge server. For the produced picture-in-picture dedicated video, because it is also regarded as an on-demand program, it is also sliced and distributed to the edge server through the content distribution network according to the rules of the video-on-demand system; because the picture-in-picture dedicated video can be considered The program is a popular on-demand program for users, so by adding special distribution rules and priorities, the video dedicated to picture-in-picture can be distributed preferentially;

d. After the TV (set-top box) activates the picture-in-picture function, it sends a signal to the video-on-demand system to order the special video of the picture-in-picture. Picture-in-picture dedicated video.

e. The local client performs decoding and decompression processing on the received picture-in-picture dedicated video, and then plays it on the picture-in-picture sub-window of the TV screen.

(2) Production of special video for picture-in-picture

The production of the picture-in-picture dedicated video is the core part of the server end of the present embodiment (above step b), which is completed by the picture-in-picture video production module placed in the server end. As shown in Figure 2, this module consists of the following three sub-modules:

Video cutting and integration module—used to cut the video stream of the arriving live program at intervals of T, and join the cut video clips end to end to form a new video clip;

Coding and compression module—used to encode and compress the video clips processed by the video cutting and integration module;

Relevant information addition module—used to add information to the video stream processed by the video cutting, integration module and encoding and compression module as an on-demand program.

As shown in Figure 2, the specific steps for making a dedicated picture-in-picture video are as follows:

b-1. For the programs of each live channel transmitted to the on-demand program source server, at a certain moment, the video segment of the previous period T time calculated from the current moment of each channel is intercepted;

b-2. If the number of live programs carried by the server is N, connect all the intercepted video segments end-to-end according to the order of channel arrangement, and generate a new video stream with a playing time of NT;

b-3. According to specific conditions such as bandwidth, processor processing capacity, etc., according to the needs of the picture-in-picture application function, perform video encoding and compression processing on the new video stream generated by interception, so as to obtain special video for picture-in-picture;

b-4. According to the design requirements of the VOD system, add the relevant information needed as an on-demand program to the produced picture-in-picture special video, and store the picture-in-picture special video as an on-demand program in the server after completion.

Therefore, in this embodiment, the dedicated video stream for picture-in-picture is periodically generated, and therefore periodically transmitted by the edge server to the local client. After accumulating several periods of dedicated picture-in-picture videos, the earlier videos are deleted.

(3) Application of local client

The produced picture-in-picture dedicated video is played through the picture-in-picture function control and playback module set on the local client terminal. As shown in Figure 3, this module is divided into two sub-modules: a picture-in-picture function control module and a picture-in-picture video playback module.

The functions of the picture-in-picture function control module are:

1. After receiving an instruction from the user to start the picture-in-picture function, the control module sends an instruction to the playback module to start working;

2. After receiving an instruction from the user to change the channel played by the picture-in-picture sub-window, the control module sends an instruction to the playback module to switch to a certain channel;

3. After receiving an instruction from the user to close the picture-in-picture function, the control module sends a signal to the playback module to stop playing and close the picture-in-picture sub-window;

The functions of the picture-in-picture video playback module are:

1. Before turning off the picture-in-picture function each time, save the current stop channel number;

2. After receiving the signal to start working from the control module, read the channel number stored before closing the picture-in-picture function last time, and select the appropriate position of the video requested by the above-mentioned control module according to the number to start transmitting data;

3. After receiving the signal to start working from the control module, the playback module sends a request for on-demand picture-in-picture video to the on-demand server, establishes a connection after passing the authentication, and begins to transmit data periodically;

4. After receiving the start signal from the control module, the playback module creates a picture-in-picture sub-window with a suitable size on the screen, and places it at the forefront of the screen;

5. After the operation described in function 3 is completed, the playback module receives and processes the media stream of the picture-in-picture video from the on-demand server;

6. When the picture-in-picture video stream from the on-demand server is buffered, the playback module will play it in the picture-in-picture sub-window;

7. After receiving a signal from the control module to change the picture-in-picture playback channel to a certain channel, the playback module reselects the playback time of the picture-in-picture video according to the channel to be changed;

8. After completing the operation of function 7, if the data of the reselected playback time has been downloaded to the local, it will be played in the picture-in-picture sub-window immediately;

9. After completing the operation of function 7, if the data at the re-selected playback time has not been downloaded, then select the appropriate position of the video requested by the above-mentioned control module according to the channel number to start transmitting data, and restart after the processing and buffering are completed play;

10. After receiving the signal to stop playing from the control module, the playback module sends a signal to the on-demand system to terminate the picture-in-picture video on demand, and terminates the data transmission;

11. After receiving the signal to stop playing from the control module, the playing module stops playing the picture-in-picture video, and closes the picture-in-picture sub-window on the screen.

As shown in Figure 3, in the application process of the local client, the specific operations are as follows:

A. The user controller (remote control, etc.) sends a control signal to the set-top box, and the set-top box recognizes the control signal. If it is related to the picture-in-picture function, the set-top box sends a control signal to the picture-in-picture function control and playback module arranged therein;

B. The picture-in-picture function control module sends corresponding control signals to the picture-in-picture video playback module according to the user's requirements, including: opening the picture-in-picture function signal, closing the picture-in-picture function signal, switching the picture-in-picture channel signal;

C. The picture-in-picture video playback module makes corresponding operations according to the control signal of the control module:

C-1 If it is a signal to turn on the picture-in-picture function, the playback module performs the following operations: read the channel that stayed when the picture-in-picture function was turned off last time, order the picture-in-picture video to the VOD system and follow the rules according to the read channel carry out data transmission;

C-2 If it is to switch the picture-in-picture channel signal, and the data at the re-selected playback time has not been downloaded, the playback module will perform the following operations: relocate the picture-in-picture video transmission position, and request to restart the data transmission;

C-3 If it is to close the picture-in-picture function signal, the playback module performs the following operations: send a signal to the VOD ordering system to terminate the picture-in-picture video on demand, and record the channel currently staying;

D. The VOD on-demand system responds to the on-demand requirements of the playback module of the local client, and transmits the picture-in-picture video to the local client;

E. The playback module performs the following operations according to the signal from the control module:

If E1 is a signal to enable the picture-in-picture function, the playback module performs the following operations: while performing the step C-1, create a picture-in-picture sub-window on the display device screen, and the picture-in-picture video is transmitted to the local, processed and buffered Then play in the above-mentioned picture-in-picture sub-window;

If E2 is to switch the picture-in-picture channel signal, the playback module performs the following operations: judge whether the picture-in-picture video segment of the channel has been downloaded to the local area, if so, relocate the playback position of the picture-in-picture video, and play it; if not, perform After the operation of the above step C-2 is completed, locate to the corresponding playback position for playback;

If E3 is a signal to close the picture-in-picture function, the playback module performs the following operations: close the picture-in-picture window while performing the operation in step C-3.

The operation process of this embodiment is as shown in Figure 4:

a. The user sends a control signal: Since the part of the user end of this embodiment is integrated in the set-top box as a functional module, the user can operate the picture-in-picture function of this embodiment through various control means, including remote control and control of the set-top box panel, etc.; if the control signal passes through the signal recognition device of the set-top box, if it is a control signal related to the picture-in-picture function of this embodiment, then proceed to step b;

b. The control signal reaches the control module of the picture-in-picture function control and playback module, and the control module sends corresponding instructions to the playback module according to the signal. If it is a signal to start the picture-in-picture function, go to step c; if it is to switch the picture-in-picture For the channel signal, go to step e; if it is a signal to close the picture-in-picture function, go to step h;

c. If the user wants to enable the picture-in-picture function, the playback module performs the following operations: c1. Read the channel where the picture-in-picture function was closed last time; c2. Order the picture-in-picture video to the on-demand server, establish a data transmission connection, and According to the channel number read by c1, the transmission starts from the corresponding position; c3, create a picture-in-picture sub-window with an appropriate size on the display device screen, and place it at the forefront of the screen;

d. The media stream information transmitted in the above step c2 is processed and buffered, and played in the picture-in-picture sub-window created in the above step c3;

e. If the user wants to switch the picture-in-picture channel, the playback module will first search in its memory (the storage device of the shared set-top box) to find out whether the picture-in-picture video segment corresponding to the target channel that the user switches has been downloaded, and if so, Go to step g; if not, go to step f;

f. Since the picture-in-picture video of the present embodiment is a certain period of time, the splicing of the video clips of each channel, for the machine, the picture-in-picture video that needs to be played by different channels in the current cycle is only a video file. Play content at different times, so the transmission of picture-in-picture video will adopt the well-known popular streaming media transmission technology; when the picture-in-picture video segment corresponding to the switched target channel has not been downloaded, it will be relocated to the target location and start transmission data;

g. If the switching target channel already has enough playback data locally, jump to the target location to start playing;

h. If the user wants to close the picture-in-picture function, the playback module performs the following operations: h1, sends a signal to the on-demand system to terminate the picture-in-picture video transmission data, and terminates the playback; h2, saves the channel where the user's current picture-in-picture stays; h3 , Close the picture-in-picture sub-window on the screen.

The dedicated picture-in-picture video produced by this embodiment is the picture-in-picture video that is closest to the current moment and has been produced and transmitted to the edge server. For example: the current real time is 14:02:30, and the latest picture-in-picture video that has been produced in the on-demand server is from 14:00:00 to 14:01:00, so the video to be downloaded It is the picture-in-picture video from 14:00:00 to 14:01:00. If the operator carries 100 live channels, the video streams of these 100 channels during the time period from 14:00:00 to 14:01:00 are copied. Connect these 100 video streams end to end to form a new video stream. Then perform encoding and compression processing according to the picture-in-picture application, so as to obtain a new picture-in-picture video stream m. For the machine, the time period from 14:00:00 to 14:01:00 of channel 1 corresponds to the playback time of the above video stream m from 00:00:00 to 00:01:00; 14:00:00 of channel 2 The content of the time period from 14:01:00 to 14:01:00 corresponds to the playing time of the above video stream m from 00:01:00 to 00:02:00; the content of the time period from 14:00:00 to 14:01:00 of channel 3 corresponds to the above video stream The playing time of m is 00:02:00 to 00:03:00...and so on.

At this time, when we turn on the picture-in-picture function, if the channel of the picture-in-picture is channel 3, the priority is 00:02 of the picture-in-picture video stream m from the above 14:00:00 to 14:01:00 time period :00 Time to start transmitting the video stream. After the video stream is processed and buffered locally, it starts playing. Since the dedicated picture-in-picture video stream m is periodically transmitted from the edge server to the local client according to the generation cycle, the content of channel 3 in the next period of time is played during the playback of channel 3. After accumulating several periods of dedicated picture-in-picture videos, the earlier videos are deleted.

The above-mentioned picture-in-picture video stream m is equivalent to a complete video clip, and because the channel switching of picture-in-picture is mostly simple operations such as "forward" and "backward" according to user habits, so when transmitting the video stream m, only need to use Some simple streaming media transmission strategies are known in the prior art. If the located location data has been downloaded, the screen will immediately turn to the located location to start playing; if the located location data has not been downloaded, it will automatically jump to this location to start downloading data, and start after buffering a certain amount of data play.

Claims (6)

1, a kind of method that realizes picture-in-picture playback function in IPTV, it is characterized in that comprising the following steps: a. The live program source server supplies live programs to users in the form of multicast, and at the same time transmits and stores the live programs of all channels to the on-demand program source server in real time; b. Make special video for picture-in-picture; c. Slice the dedicated video for picture-in-picture, and distribute it to the edge server through the content distribution network according to the rules of the video-on-demand system; d. After the local user terminal activates the picture-in-picture function, it sends a signal to the video-on-demand system to order the special video of the picture-in-picture. Painting dedicated video; e. The local client terminal performs decoding and decompression processing on the received picture-in-picture dedicated video, and then plays it on the picture-in-picture sub-window of the TV screen. 2, the method for realizing picture-in-picture playback function in IPTV according to claim 1, it is characterized in that the step of described step b making picture-in-picture special video is as follows: b-1. For the programs of each live channel transmitted to the on-demand program source server, at a certain moment, the video segment of the previous period T time calculated from the current moment of each channel is intercepted; b-2. Connect all the intercepted video segments end-to-end according to the order of channels to form a new video stream; b-3. According to the needs of the picture-in-picture application function, perform video encoding and compression processing on the new video stream generated by interception, so as to obtain the special video for picture-in-picture; b-4. According to the design requirements of the VOD system, add the relevant information needed as an on-demand program to the produced picture-in-picture special video, and store the picture-in-picture special video as an on-demand program in the server after completion. 3. The method for realizing the picture-in-picture playback function in IPTV according to claim 2, characterized in that: in the process of transmitting the dedicated picture-in-picture video from the edge server to the user, according to the generation cycle of the dedicated picture-in-picture video, Periodically transmit to the local client; after accumulating several cycles of dedicated picture-in-picture videos, delete earlier videos. 4. The method for realizing the picture-in-picture playback function in IPTV according to claim 2, characterized in that: the dedicated video for picture-in-picture is produced by a picture-in-picture video production module, which is placed on the server side and includes The following three submodules: The video cutting and integration module is used to cut the video stream of the arriving live program at intervals of T, and connect the cut video clips end to end into a new video clip; An encoding and compression module is used to encode and compress the video clips processed by the video cutting and integration module; The relevant information adding module is used for adding information to the video stream processed by the video cutting, integrating module and encoding and compressing module as an on-demand program. 5. The method for realizing the picture-in-picture playback function in IPTV according to claim 1, characterized in that: in the process of distributing the special video for the picture-in-picture to the edge server, by adding special distribution rules and priorities, the picture-in-picture The special video for medium picture will be distributed first. 6. The method for realizing the picture-in-picture playback function in IPTV according to claim 1, characterized in that: the special video for the picture-in-picture is played at the local user end through the picture-in-picture function control and playback module, and the module Including picture-in-picture function control module and picture-in-picture video playback module, in which: The picture-in-picture function control module is used to receive instructions from the user about picture-in-picture related functions, and send instructions to the picture-in-picture video playback module to turn on, switch channels, and turn off picture-in-picture functions; The picture-in-picture video playback module is used to receive instruction signals from the control module and perform corresponding operations, send an on-demand request to the edge server, and receive and play video data transmitted from the edge server.

Images