WO2017028675A1

WO2017028675A1 - Playing method, device and system for live streaming channel

Info

Publication number: WO2017028675A1
Application number: PCT/CN2016/092714
Authority: WO
Inventors: 陈志中; 李锐; 朱兴昌; 刘学安; 朱伟
Original assignee: 中兴通讯股份有限公司
Priority date: 2015-08-18
Filing date: 2016-08-01
Publication date: 2017-02-23
Also published as: CN106470352A; CN106470352B

Abstract

A playing method for a live streaming channel comprises: a player acquires segment information of media file segments, wherein the segment information comprises a start time point of the media file segments; the player determines, on the basis of the start time point, a play location corresponding to a first time point in the acquired media file segments; the player starts playing of the live streaming channel from the play location, wherein a time difference between a current time of the player and the first time point is a predetermined time duration, and the current time is synchronized with the time of a device generating the media file segments. Via the above solution, the present invention addresses the asynchronicity problem of play frames of an HLS-based live streaming channel, such that the play frames are synchronized to improve user experience.

Description

Live channel playing method, device and system

Technical field

The present application relates to, but is not limited to, the field of communications, and in particular, to a live channel playing method, apparatus, and system.

Background technique

The development of digital multimedia and networks facilitates users' access to information or entertainment experiences. People can watch live channels in a variety of ways, such as satellite TV, cable TV, Internet TV and more. There are many different methods for providing live video services on the Internet, such as Real Time Streaming Protocol (RTSP) and Hypertext Transfer Protocol (HTTP) based streaming media network transmission. Protocol (Http Live Streaming, referred to as HLS).

The HLS protocol is an HTTP-based streaming media transfer protocol implemented by Apple Inc., which enables live streaming and on-demand streaming. It is mainly used in iOS systems to provide audio and video for iOS devices (such as iPhone, iPad, Mac, etc.). Live and on-demand programs.

For HLS live broadcast, due to its technical characteristics, it is actually progressive download. What the client gets is not a complete data stream. The server side cuts the live stream into multiple consecutive media files (eg, 10 seconds) (eg, MPEG-TS format) and is described by an constantly updated index file (m3u8 formatted text). . After continuously downloading and analyzing the index file, the client downloads the media file fragment described in the index file according to the index file prompt, and starts to play the first media file fragment from the download, and continuously plays the media file fragments; The end will cut the latest live data to generate a new small media file fragment, so that the client can continuously and continuously play the media file fragment obtained from the server in order, thus realizing continuous uninterrupted live broadcast service.

For the HLS live channel service provided in the IPTV (Internet Protocol Television)/OTT (Over The Top) system, when the set-top box enters the channel, the content delivery network (Content Delivery Network, which is referred to as the content delivery network) Download and analyze the current m3u8 index file of the channel in the CDN) streaming server, and then according to the index file After the sequential downloading obtains at least two media file fragments, starting from the first media file fragmentation, continuous display playback of the media file fragments is performed. However, this poses a problem: Since the media file fragmentation has a fixed duration, here is 10 seconds, so the index file is also updated in 10 seconds. Then, two set-top boxes of the same model under the same network bandwidth condition, when successively enter the same channel (for example, 2 seconds apart), the obtained index files are the same, and the first two media files are downloaded after being downloaded separately. This causes the two set-top boxes to be out of sync with the live broadcast screen displayed on the same channel at the same time. There is a time difference. This difference is the time difference of entering the channel.

In addition, when two set-top boxes of the same model under different bandwidth conditions are simultaneously viewed in the same HLS live channel, the bandwidth difference between downloading the m3u8 index file and the media file fragment is time-consuming, which also causes these two The set-top boxes are out of sync for the same live broadcast screen.

In view of the problem that the HLS-based live channel playback pictures are not synchronized in the related art, an effective solution has not been proposed yet.

Summary of the invention

The following is an overview of the topics detailed in this document. This Summary is not intended to limit the scope of the claims.

The embodiment of the invention provides a live channel playing method, device and system, so as to at least solve the problem that the HLS-based live channel playing screen is not synchronized in the related art.

According to an aspect of the present invention, a live channel playing method is provided, including: a player acquiring fragmentation information of a media file fragment, where the fragmentation information includes: a start time of a media file fragmentation; The player determines, according to the start time, a play position corresponding to the first time in the obtained media file fragment; the player starts playing the live channel from the play position; The time difference between the current time of the player and the first time is a preset duration; the current time is synchronized with the time of the device that generates the media file fragmentation.

Optionally, the player determines, according to the start time, that the played position corresponding to the first time in the obtained media file fragment includes: the player according to the current Determine the first time according to the time and the preset duration; the player determines, according to the start time, a frame rate of the media file fragment, and determines the media file fragmentation Narrative The corresponding playback position at a time.

Optionally, after the player starts playing the live channel from the playing position, the method further includes: the player determining whether the preset time is reached; and determining that the preset time arrives, The player corrects the playing progress of the live channel according to the preset time and the preset duration.

Optionally, the correcting the playing progress of the live channel according to the preset time and the preset duration includes: determining, by the player, the second corresponding to the current playing position at the preset time The player compares the relationship between the actual time difference between the preset time and the second time and the preset duration; when it is determined that the actual time difference is greater than the preset duration The player accelerates the playing of the live channel according to the first preset policy; and if it is determined that the actual time difference is less than the preset duration, the player follows the second preset policy. Slow down the playback of the live channel.

Optionally, the first preset policy includes: repeatedly discarding frames between two non-adjacent I frames in the media file fragment in a process of decoding the media file fragment; The P frame is preferentially discarded, and the P frame is discarded without the B frame; the number of discarded frames is determined according to at least a difference between the actual time difference and the preset duration.

Optionally, the second preset policy includes: performing a repeated play on a specific frame in the media file fragmentation; wherein, the number of the specific frames that are repeatedly played is at least according to the preset duration and the actual The difference between the time differences is determined, and the specific frame includes at least one of the following: an I frame, a P frame, and a B frame.

According to another aspect of the present invention, a live channel playback device is further provided, which is applied to a player, and includes: a processing module, configured to obtain fragmentation information of a media file fragment, wherein the fragmentation information includes And a determining module, configured to determine, according to the starting time, a playback position corresponding to the first time in the obtained media file fragment; the playing module is set to be The playing position starts to play the live channel; wherein, the time difference between the current time of the player and the first time is a preset duration; the current time is related to the device that generates the media file fragmentation The time is synchronized.

Optionally, the determining module includes: a first determining unit, configured to determine the first time according to the current time and the preset duration; and the second determining unit is configured to be at the start time The playback position corresponding to the first time in the media file fragment is determined according to a frame rate of the media file fragment.

Optionally, the device further includes: a determining module, configured to determine whether the preset time is reached; and a correction module configured to determine, according to the preset time and the preset duration, that the preset time is reached Correcting the progress of playing the live channel.

Optionally, the correction module includes: a third determining unit configured to determine a second time corresponding to the current playing position at the preset time; and a comparing unit configured to compare the preset time with the second time The relationship between the actual time difference and the preset duration; the first processing unit is configured to speed up the location according to the first preset policy when it is determined that the actual time difference is greater than the preset duration The playing of the live channel is performed. The second processing unit is configured to slow down the playing of the live channel according to the second preset policy if it is determined that the actual time difference is less than the preset duration.

According to another aspect of the present invention, a live channel playing system is further provided, including: a set top box, a content distribution network, and a time synchronization source, wherein the content distribution network is connected to the set top box and configured to be based on a live broadcast. Generating a media file fragment and an index file, and providing the set top box with the download of the media file fragment and the update of the index file; wherein the index file describes the fragmentation of the media file fragment Information, the fragmentation information includes: a start time of the media file fragmentation; the set top box is configured to acquire an index file from the content distribution network, and parse the fragmentation information; and obtain the fragmentation information according to the fragmentation information Decoding the media file; determining, according to the start time, a play position corresponding to the first time in the media file segment; and playing the live channel from the play position; wherein Current time of the set top box The time difference from the first time is a preset time length; the time synchronization source is respectively connected to the content distribution network and the set top box, and is set to synchronize the time of the set top box and the content distribution network.

The embodiment of the invention further provides a computer readable storage medium storing computer executable instructions, which are implemented when the computer executable instructions are executed.

According to the embodiment of the present invention, the fragmentation information of the media file fragment is obtained by using the player, where the fragmentation information includes: a start time of the media file fragmentation; and the player determines the obtained media file based on the start time. a playback position corresponding to the first time in the fragment; the player starts playing the live channel from the playback position; wherein, the time difference between the current time of the player and the first time is a preset duration; the current time and the generated media file The time of the fragmented device is synchronized, which solves the problem that the HLS-based live channel playback screen is out of sync, so that the playback screen can be synchronized, which improves the user experience.

Other aspects will be apparent upon reading and understanding the drawings and detailed description.

BRIEF abstract

The drawings described herein are intended to provide a further understanding of the present application, and are intended to be a part of this application. In the drawing:

1 is a flowchart of a live channel playing method according to an embodiment of the present invention;

2 is a schematic structural diagram of a live channel playing device according to an embodiment of the present invention;

3 is a schematic structural diagram 1 of an optional structure of a live channel playing device according to an embodiment of the present invention;

4 is a second schematic diagram of an optional structure of a live channel playing device according to an embodiment of the present invention;

FIG. 5 is a third schematic diagram of an optional structure of a live channel playing device according to an embodiment of the present invention; FIG.

6 is a schematic structural diagram of a live channel playing system according to an embodiment of the present invention;

7 is a first schematic diagram of an HLS live channel playback screen synchronization system according to an alternative embodiment of the present application;

FIG. 8 is a schematic diagram of an HLS live channel playback screen synchronization system according to an alternative embodiment of the present application. Figure II;

9 is a flowchart 1 of a method for synchronizing an HLS live channel playback screen according to an alternative embodiment of the present application;

FIG. 10 is a second flowchart of a method for synchronizing an HLS live channel playback screen according to an alternative embodiment of the present application; FIG.

11 is a schematic diagram 1 of a scene of HLS live channel picture synchronization according to an alternative embodiment of the present application;

FIG. 12 is a second schematic diagram of a scenario of HLS live channel picture synchronization according to an alternative embodiment of the present application; FIG.

FIG. 13 is a third schematic diagram of a scenario of HLS live channel picture synchronization according to an alternative embodiment of the present application; FIG.

FIG. 14 is a fourth schematic diagram of a scene of HLS live channel picture synchronization according to an alternative embodiment of the present application.

Embodiments of the invention

The present application will be described in detail below with reference to the drawings in conjunction with the embodiments. It should be noted that the embodiments in the present application and the features in the embodiments may be combined with each other without conflict.

It should be noted that the terms "first", "second" and the like in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or order.

In this embodiment, a live channel playing method is provided. FIG. 1 is a flowchart of a live channel playing method according to an embodiment of the present invention. As shown in FIG. 1 , the method includes the following steps:

In step S102, the player obtains the fragmentation information of the fragment of the media file, where the fragmentation information includes: a start time of the fragmentation of the media file;

Step S104: The player determines, according to the start time, a play position corresponding to the first time in the obtained media file fragment;

Step S106, the player starts playing the live channel from the playing position; wherein the player The time difference between the current time and the first time is a preset duration; the current time is synchronized with the time of the device that generated the media file fragmentation.

Through the above steps, since the current time of the player is synchronized with the time of the device for generating the media file fragmentation, when the media file fragment is generated, the start time of the media file fragmentation is recorded; then, the media is acquired by the player. After the start time of the file fragmentation, the playback time corresponding to the first time in the media file fragment can be determined based on the start time, and the live channel is played from the play position; wherein, the current time of the player The time difference from the first time is the preset time length, so that when the player starts playing, the time corresponding to the playback position always lags the actual time by a fixed amount of time, thereby ensuring multiple players. The screen is synchronized when playing a live channel. It can be seen that through the above steps, the problem that the live channel playback screen based on HLS is not synchronized is solved, so that the playback screen can be synchronized, and the user experience is improved.

Optionally, in the HLS-based progressive live broadcast system, the fragmentation information of the media file fragment is sent and updated to the player through the index file, and the index file is an m3u8 index file; in addition, the player is delivered or updated according to the identifier. The fragmentation information of the media file fragmentation described in the index file obtains the media file fragmentation. The start time of the media file fragmentation refers to the real time of generating the media file fragment, or the actual time represented by the content of the media file fragmentation record. For example, for a 10-second media file fragmentation, assuming that the actual content recorded is a live broadcast between 8:00:00 and 8:00:10, the start time of the above-mentioned media file fragmentation is 8:00:00.

The frame rate represents the number of frames per unit time; that is, the media stream of known frame rate, the number of frames per unit time is also known. Optionally, in step S104, the player may determine the first time according to the current time and the preset duration; the player determines the media file fragmentation based on the start time and combined with the frame rate of the media file fragmentation. The playback position corresponding to the first time.

Optionally, after the player starts playing the live channel from the playing position, the player may further determine whether the preset time is reached; and when determining that the preset time arrives, the player according to the preset time and the preset duration Correct the progress of the live channel. During the playback of the media stream, due to network reasons, etc., problems such as frame dropping or repeated parsing may occur, resulting in a delay or advancement of the playback screen after a certain playback time. By adopting the above correction method, the playback progress can be corrected when the preset time arrives; wherein the preset time can be freely set, and can be set to a time after the fixed play duration, for example, once every half hour of the live broadcast. Correction It can also be set to a fixed point in time, for example, once every hour or half arrives.

Optionally, the player corrects the playing progress of the live channel according to the preset time and the preset duration: the player determines the second time corresponding to the current playing position at the preset time; the player compares the preset time with the second time The actual time difference is related to the preset duration; if it is determined that the actual time difference is greater than the preset duration, the player speeds up the playback of the live channel according to the first preset policy; If the duration is less than the preset duration, the player slows down the playback of the live channel according to the second preset policy.

Optionally, the first preset policy refers to a policy of dropping frames. For example, in the process of decoding a media file fragment, the frame is repeatedly discarded between two non-adjacent I frames in the media file fragment; wherein, the B frame is preferentially discarded, and is discarded without the B frame. P frame; the number of discarded frames is determined based at least on the difference between the actual time difference and the preset duration. Through the above strategy, the playback of the live channel can be speeded up, and, in the above strategy, the frame is repeatedly discarded between two I frames that are not adjacent in the media file fragment, so that the accelerated playback is smooth, not Will affect the user's viewing experience.

Optionally, the second preset policy refers to a policy of repeatedly playing a specific frame. For example, performing a repeated play on a specific frame in the media file fragmentation; wherein, the number of the specific frames that are repeatedly played is determined according to a difference between the preset duration and the actual time difference, and the specific frame includes at least the following One: I frame, P frame, B frame. Similarly, in the above strategy, since the playback is performed only once for a specific frame, the slow playback is smooth and does not affect the user's viewing experience.

Through the description of the above embodiments, those skilled in the art can clearly understand that the method according to the above embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, by hardware, but in many cases, the former is A better implementation. Based on such understanding, the technical solution of the present application, which is essential or contributes to the related art, may be embodied in the form of a software product stored in a storage medium (such as ROM/RAM, disk, CD-ROM). The instructions include a number of instructions for causing a terminal device (which may be a cell phone, computer, server, or network device, etc.) to perform the methods described in each embodiment of the present application.

In this embodiment, a live channel playing device is also provided, and the device is applied to the player, and is used to implement the foregoing embodiments and optional embodiments. As below As used, the term "module" can implement a combination of software and/or hardware for a predetermined function. Although the apparatus described in the following embodiments is preferably implemented in software, hardware, or a combination of software and hardware, is also possible and contemplated.

2 is a structural block diagram of a live channel playing device according to an embodiment of the present invention. As shown in FIG. 2, the device includes: a processing module 22, a determining module 24, and a playing module 26; and a processing module 22 configured to obtain an index file, and Parsing the fragmentation information of the media file fragmentation described in the index file, where the fragmentation information includes: a start time of the media file fragmentation; the determining module 24 is coupled to the processing module 22, and is set to be based on the start time. Determining a play position corresponding to the first time in the media file fragmentation; the playing module 26 is coupled to the determining module 24, configured to play the live channel from the play position; wherein, the current time of the player and the time of the first time The difference is the preset duration; the current time is synchronized with the time of the device that generated the fragmentation of the media file.

Through the comprehensive function of the above modules, the problem that the live channel playback screen based on HLS is not synchronized is solved, so that the playback screen can be synchronized and the user experience is improved.

FIG. 3 is a block diagram of an optional structure of a live channel playing device according to an embodiment of the present invention. On the basis of the live channel playing device shown in FIG. 2, as shown in FIG. 3, optionally, the determining module 24 includes: a determining unit 242 is configured to determine the first time according to the current time and the preset duration; the second determining unit 244 is coupled to the first determining unit 242, and is set to be based on the starting time and combined with the media file fragmentation. The frame rate determines the playback position corresponding to the first time in the media file fragment.

4 is a block diagram of an optional structure of a live channel playing device according to an embodiment of the present invention. On the basis of the live channel playing device shown in FIG. 2, as shown in FIG. 4, the device further includes: The determining module 42 is coupled to the playing module 26 and configured to determine whether the preset time is reached. The correcting module 44 is coupled to the determining module 42 and configured to determine the preset time and the preset time according to the preset time and the preset time length. Correct the progress of the live channel.

FIG. 5 is a block diagram 3 of an optional structure of a live channel playing device according to an embodiment of the present invention. On the basis of the live channel playing device shown in FIG. 4, as shown in FIG. 5, optionally, the correcting module 44 includes: The third determining unit 442 is configured to determine a second time corresponding to the current playing position at the preset time; the comparing unit 444 is coupled to the third determining unit 442, and is configured to compare the actual time difference between the preset time and the second time with the pre-predetermined time The first processing unit 446 is coupled to the comparison unit 444, and is configured to be configured according to the first step when it is determined that the actual time difference is greater than the preset duration. The preset policy speeds up the playing of the live channel; the second processing unit 448 is coupled to the comparing unit 444, and is configured to slow down the live channel according to the second preset policy if it is determined that the actual time difference is less than the preset duration Play.

Optionally, the first preset policy includes: repeatedly discarding frames between two non-adjacent I frames in the media file fragment in the process of decoding the media file fragment; wherein, preferentially discarding the B frame P frames are discarded without B frames; the number of discarded frames is determined based at least on the difference between the actual time difference and the preset duration.

Optionally, the second preset policy includes: performing a repeated play on a specific frame in the media file fragmentation; wherein, the number of the specific frames that are repeatedly played is at least a difference between the preset duration and the actual time difference. Determining, the specific frame includes at least one of the following: an I frame, a P frame, and a B frame.

Optionally, the player described above includes: a playback device having a frame parsing function, such as a set top box or the like.

This embodiment also provides a live channel playing system. FIG. 6 is a schematic structural diagram of a live channel playing system according to an embodiment of the present invention. As shown in FIG. 6, the system includes: a set top box 62, a content distribution network 64, and time synchronization. Source 66, where:

The content distribution network 64 is connected to the set top box 62 and configured to generate a media file fragment and an index file according to the live broadcast source, and provide the set top box 62 with the download of the media file fragment and the update of the index file; wherein the index file describes the media file. The fragmentation information of the fragment, the fragmentation information includes: the start time of the fragmentation of the media file;

The set top box 62 is configured to obtain an index file from the content distribution network 64, and parse the fragmentation information; obtain the media file fragment according to the fragmentation information; and determine, according to the start time, the media file fragment corresponding to the first time. a playback position; and playing the live channel from the playback position; wherein the time difference between the current time of the set top box 62 and the first time is a preset duration;

The time synchronization source 66 is connected to the content distribution network 64 and the set top box 62, respectively, and is set to synchronize the time of the set top box 62 and the content distribution network 64.

In addition, the set top box 62 is also used to implement the above-mentioned live channel playing method, and details are not described herein again.

It should be noted that each of the above modules can be implemented by software or hardware, and The foregoing may be implemented by, but not limited to, the above modules are all located in the same processor; or, the above modules are respectively located in multiple processors.

The embodiment of the present invention further provides a software for executing the technical solutions described in the foregoing embodiments and optional implementation manners.

The embodiment of the invention further provides a computer readable storage medium. In the present embodiment, the computer readable storage medium described above may be arranged to store program code for performing the following steps:

In step S1, the player obtains the fragmentation information of the fragment of the media file, where the fragmentation information includes: a start time of the fragmentation of the media file;

Step S2, the player determines, according to the start time, a play position corresponding to the first time in the obtained media file fragment;

Step S3: The player starts playing the live channel from the playing position; wherein, the time difference between the current time of the player and the first time is a preset duration; the current time is synchronized with the time of the device that generates the media file fragmentation. .

Optionally, in this embodiment, the computer readable storage medium may include, but is not limited to, a USB flash drive, a Read-Only Memory (ROM), a Random Access Memory (RAM), and a mobile device. A variety of media that can store program code, such as hard disks, disks, or optical disks.

For example, the specific examples in this embodiment may refer to the examples described in the foregoing embodiments and the optional embodiments, and details are not described herein again.

Description and description are made below in conjunction with alternative embodiments.

An optional embodiment of the present application provides a method and system for solving the problem that the HLS live channel playback screen is out of synchronization, so as to enhance the user's viewing experience for the HLS channel. The method provided by this alternative embodiment includes the following steps:

Step 1. The CDN streaming server (equivalent to the content distribution network described above) and the set-top box playing client (corresponding to the above-mentioned player) perform clock synchronization with the same clock synchronization source to ensure that the time between the two is completely the same.

Step 2: When the media file is cut and the m3u8 index file is updated, the CDN streaming server adds a fragment creation time attribute for each media file fragment, and the fragment creation time attribute representation The actual start time of the media file fragmentation.

Step 3: When the set-top box playing client enters the HLS channel for playing, after the first two media files are downloaded, the first media file segmentation is no longer started, but the current system time of the client is subtracted from the set-top box. The fixed duration (such as the length of the two media file fragments) t0 starts to play. This effectively solves the time difference between the different set-top box playing client entering the channel, or the time difference caused by the download speed of different network bandwidth differences, which causes the HLS channel live picture to be out of sync.

Optionally, at each hour, the set-top box playing client corrects the playing position of the t0 according to the local time of the system, and if there is a lag, the decoding is accelerated until the lag time is corrected, and the correcting mechanism is implemented. The problem of playback is not synchronized caused by Caton or network transmission.

In order to implement the above method, an optional embodiment of the present application further provides a system for solving the problem of non-synchronization of the HLS live channel playback screen, the system comprising: cutting a media file fragment and updating the index file of the CDN streaming server, downloading and correcting The set-top box that does not synchronize the problem plays the client, and the clock synchronization server (which is equivalent to the above-mentioned time synchronization source) that performs clock synchronization between the two.

The method and system for solving the problem of non-synchronization of the HLS live channel playback screen provided by the optional embodiment of the present application, by adding a synchronization policy between the CDN streaming media server and the set-top box playing client, to implement a plurality of set-top box playing clients The live channel picture synchronization can realize the synchronization correction of the picture of the same HLS live channel under different conditions of different set-top box playing client and different network bandwidth, and bring a more real-time viewing experience to the user.

The following describes the exemplary embodiments of the present application with reference to the accompanying drawings and the drawings.

An optional embodiment of the present application describes an HLS live channel playback screen synchronization system. As shown in FIG. 7 and FIG. 8, the system includes a set top box playback client, a CDN streaming server, and a clock synchronization server.

Among them, the clock synchronization server serves as the clock source for the entire system. The set-top box playback client and the CDN streaming media server are clock synchronized with the clock synchronization server to ensure complete synchronization of the clock between the set-top box playing client and the CDN streaming server.

The CDN streaming media server provides the source of the HLS live channel, provides the m3u8 index file of the channel and the download service of the channel media file fragment, and repeatedly updates according to the live broadcast process. M3u8 indexing, as well as creating new media file shards.

As shown in FIG. 8, the set top box playing client includes: a downloading module, a codec module, and a video rendering module. The download module is responsible for downloading and parsing the m3u8 index file, and downloading the media file fragment described in the m3u8 index file; the codec module is responsible for decoding the ts format of the media file fragmentation, so that the video rendering module can display the screen. Displayed to the user, at the same time the codec module is also responsible for speeding up the decoding work when the whole point check finds that there is a delay in playback progress, in order to catch up with the playback progress.

Based on the above system, an optional embodiment of the present application further provides a method for synchronizing HLS live channel playback pictures. The method will be described below with reference to the following examples of index files, FIG. 9 and FIG.

Among them, an example of an index file is as follows:

The CDN streaming server increases the generation time description information of each media file fragment in the m3u8 index file of the provided HLS live channel, and generates time description information using the #EXT-X-PROGRAM-DATE-TIME parameter description. The time description information is generated, which will serve as a reference for ensuring the synchronization of the playback screen when the different set-top box playback client plays after the download is completed, and will also serve as a reference for the set-top box playback client to keep the playback screen synchronized during the continuous playback.

FIG. 9 shows a business process when the set-top box playing client enters the HLS live channel according to the user instruction. As shown in FIG. 9, first, the set-top box playing client queries the CDN streaming server for the playing address of the HLS live channel; and the CDN streaming server returns the file transfer protocol (FTP, File Transfer Protocol) of the m3u8 index file of the HLS live channel according to the request. download link; The set-top box playing client downloads the first m3u8 index file according to the FTP download address; the set-top box playing client parses the first m3u8 index file, obtains the media file fragment of the HLS live channel described in the index file, and each media The playback duration of the file fragment, the generation time of each media file fragmentation (ie, the EXT-X-PROGRAM-DATE-TIME time described above); the set-top box playback client subtracts t0 according to its own system time (for example, the value of t0 can be selected) As the starting time of the two media files, as the starting time of the current playback; the set-top box playing client opens the first media file fragment, and jumps to the starting moment to start playing.

As shown in FIG. 10, in the process of media file fragmentation of the normal playing HLS channel, the set-top box playing client checks whether the current playing position of the media file and the system time of the set-top box playing the client itself are different when the clock is in the whole point. Playback delay. If a media file fragment is currently being played to the t1 position, the generation time t2 of the media file fragment (the aforementioned EXT-X-PROGRAM-DATE-TIME time attribute) is taken, and the current playback position is t3=t2+. T1. Compare the difference between the set-top box playback client's own system time t4 and t3 t5=t4-t3, compared with t0 in Figure 9:

A. If t5>t0, it means that the set-top box playing client has a delay in the current HLS channel playing process, and needs to accelerate the decoding display. The set-top box playing client controls the codec module to discard a certain number of video frames according to the strategy according to the difference between t5 and t0 to catch up with the playing progress.

Optionally, the above strategies include:

A1: Do not repeatedly discard frames between two adjacent I frames;

A2, each time the frame is dropped, the nearest B frame is discarded first; if there is no B frame, the P frame is discarded;

A3. The number of dropped frames is calculated according to the difference between t5 and t0 and the compression ratio of the media file;

According to the strategy, the frame loss is matched to the playback progress, and the impact on the user's playback experience can be neglected, and there is no obvious misalignment on the video.

B. If t5=t0, it means that the set-top box playing client does not have a delay during the current HLS channel playing, and does not need additional synchronization adjustment, and can normally download and play.

C. If t5 < t0, it means that the playback progress of the set-top box playing client caused by the frame skipping during the current HLS playback is too fast, and the playback progress needs to be delayed. The set top box plays the client according to t0 and The difference of t5 controls the codec module to compensate for a certain number of video frames according to the strategy to delay the waiting for playing progress. The so-called compensation means that a certain frame is repeatedly played.

Optionally, the above strategies include:

C1, each original frame can only be compensated once;

C2, the original frame compensated may be an I frame, a P frame or a B frame, and there is no mandatory requirement;

C3, the number of compensation frames in this time is calculated according to the difference between t0 and t5 and the compression ratio of the media file;

According to the above discarding frame or compensating frame strategy, the playback progress synchronization is realized, and the influence on the user's playing experience can be neglected, and there is no obvious jump or delay in the video.

As shown in FIG. 11 to FIG. 14 , for a different set-top box playing client (referred to as a client), multiple combinations under different network bandwidth conditions, the method provided by the optional embodiment of the present application is used to solve the unsynchronized playback scene of the HLS live channel. Different embodiments of the problem. The following will be introduced one by one.

In the example shown in FIG. 11, the client 1 and the client 2 are set top boxes of the same model. Client 1, in the network bandwidth 1 condition; client 2, in the network bandwidth 2 condition. The client 1 and the client 2 initiate a viewing request for the same HLS live channel at the same time t1. Due to the bandwidth difference, the client 1 downloads the m3u8 index file of the HLS live channel and the described description relatively quickly at time t2. The first two media files are fragmented; the client 2 downloads the m3u8 index file of the HLS live channel and the first two media file fragments described at t3 relatively slowly.

If both clients are playing from the beginning of the first media file fragment downloaded, it is inevitable that the playback screen of the client 1 is earlier than the playback screen of the client 2.

With the method of the embodiment of the present invention, after completing the download at time t2, the client 1 subtracts the fixed duration t0 (as described above) from the current time t2 of the client 1, that is, plays from t2-t0, and reaches the client at time t3. The playback screen of 1 is located at t2-t0+(t3-t2)=t3-t0; at this time, client 2 just completes the download, and subtracts the fixed duration t0 (as described above) from the current time t3 of client 2, that is, from t3- The playback is performed at t0, which coincides with the playback position of the client 1. This ensures that the client 1 and the client 2 synchronize the playback picture when entering the same HLS live channel under different network bandwidth conditions.

In the example shown in Figure 12, client 1 and client 2 are two identical models and are on the same network. Under the condition of bandwidth 1. The client 1 starts to request a certain HLS live channel at an earlier time t1, and completes the download of the m3u8 index file and the first two media file fragments described therein at time t3; the client 2 requests the same HLS at a later time t2. The live channel completes the download of the m3u8 index file and the first two media file fragments described therein at time t4. The playback time of client 1 is t3-t0. When it reaches time t4, the playback position of client 1 is t3-t0+(t4-t3)=t4-t0; the playback time of client 2 is t4-t0, just like the client. The playback position of the end 1 is the same. This ensures that the client 1 and the client 2 are synchronized to the playback screen when playing the same HLS live channel at different times under the same network bandwidth condition.

In the example shown in FIG. 13, client 1 and client 2 are two identical models and are in the same network bandwidth 1 condition. Client 1 starts to request the HD version of a certain HLS live channel at time t1, and completes the download of the m3u8 index file and the first two HD media file fragments described therein at time t3; client 2 requests the same at the same time t1. The standard definition version of the HLS live channel, because the SD media segment file is small, takes up a short download time, so the m3u8 index file and the download of the first two SD media file segments described therein are completed at t2 before t3. The playback time of client 2 is t2-t0. When t3 is reached, the playback position of client 2 is t2-t0+(t3-t2)=t3-t0; the playback time of client 1 is t3-t0, just like the client. The playback position of the end 2 is the same. This ensures that Client 1 and Client 2 synchronize the playback pictures of the HD and SD channels of the same HLS live channel under the same network bandwidth conditions.

In the example shown in FIG. 14, client 1 and client 2 are two set top boxes of the same model. Client 1, under the condition of network bandwidth 1 with normal bandwidth conditions; client 2, under the condition of better bandwidth of network bandwidth 2. Both clients are watching the same HLS live channel, and at time t1, the two clients play the same position and the pictures are synchronized. After a period of time, due to the bandwidth limitation of the network bandwidth 1, there is a situation in which the download cannot keep up and the playback progress is delayed. At a certain hour t2, the client 2 is in the normal play position, and the client 1 is relatively lagging. At this time, the play picture between the two is out of sync. With the method of the embodiment of the present invention, the client 1 checks that the playback position is delayed compared with the current device time (t2) minus the fixed duration (t0) at the hour, and the client 1 itself speeds up the decoding and plays. The normal playback progress is consistent with the standard playback screen.

Those skilled in the art will appreciate that the modules or steps of the present application described above can be implemented with a general purpose computing device that can be centralized on a single computing device or distributed across multiple computations. Optionally, they may be implemented by program code executable by the computing device, such that they may be stored in the storage device by the computing device and, in some cases, may be different The steps shown or described herein are performed sequentially, or they are separately fabricated into a single integrated circuit module, or a plurality of modules or steps thereof are fabricated as a single integrated circuit module. Thus, the application is not limited to any particular combination of hardware and software.

The above description is only an optional embodiment of the present application, and is not intended to limit the present application, and various changes and modifications may be made to the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this application are intended to be included within the scope of the present application.

Industrial applicability

The embodiment of the present invention provides a live channel playing method, device, and system, which solves the problem that the live channel playback screen based on the HLS is not synchronized, so that the playback screen can be synchronized, and the user experience is improved.

Claims

A live channel playing method includes:

The player obtains the fragmentation information of the fragment of the media file, where the fragmentation information includes: a start time of the fragmentation of the media file;

The player determines, according to the start time, a play position corresponding to the first time in the obtained media file fragment;

The player starts playing of a live channel from the playing position;

The time difference between the current time of the player and the first time is a preset duration; the current time is synchronized with the time of the device that generates the fragmentation of the media file.
The method of claim 1, wherein the player determines, according to the start time, that the played position corresponding to the first time in the obtained media file fragment comprises:

Determining, by the player, the first time according to the current time and the preset duration;

The player determines, according to the start time, a playback position corresponding to the first time in the media file fragment according to a frame rate of the media file fragment.
The method according to claim 1, after the player starts playing the live channel from the playback position, the method further includes:

The player determines whether the preset time has arrived;

When it is determined that the preset time arrives, the player corrects the playing progress of the live channel according to the preset time and the preset duration.
The method according to claim 3, wherein the player corrects the progress of playing the live channel according to the preset time and the preset duration:

Determining, by the player, the second time corresponding to the current playing position at the preset time;

The player compares the actual time difference between the preset time and the second time and the size relationship of the preset duration;

When it is determined that the actual time difference is greater than the preset duration, the player speeds up playing of the live channel according to the first preset policy;

When it is determined that the actual time difference is less than the preset duration, the player slows down the playing of the live channel according to the second preset policy.
The method according to claim 4, wherein the first preset policy comprises: in the process of decoding the media file fragment, two non-adjacent I in the media file fragment Repeatingly discarding frames between frames; wherein, the B frames are preferentially discarded, and the P frames are discarded without the B frames; the number of discarded frames is at least based on the difference between the actual time difference and the preset duration The value is determined.
The method according to claim 4, wherein the second preset policy comprises: performing a repeated play of a specific frame in the media file fragment; wherein the number of specific frames repeatedly played is at least according to the method Determining, by the difference between the preset duration and the actual time difference, the specific frame includes at least one of the following: an I frame, a P frame, and a B frame.
A live channel playing device is applied to a player, including:

The processing module is configured to obtain the fragmentation information of the fragment of the media file, where the fragmentation information includes: a start time of the fragmentation of the media file;

a determining module, configured to determine, according to the start time, a play position corresponding to the first time in the obtained media file fragment;

a playing module, configured to start playing a live channel from the playing position;

The time difference between the current time of the player and the first time is a preset duration; the current time is synchronized with the time of the device that generates the fragmentation of the media file.
The apparatus of claim 7, wherein the determining module comprises:

a first determining unit, configured to determine the first time according to the current time and the preset duration;

The second determining unit is configured to determine, according to the start time, a playback position corresponding to the first time in the media file fragment, in combination with a frame rate of the media file fragment.
The apparatus of claim 7 further comprising:

The judging module is configured to determine whether the preset time has arrived;

a correction module configured to determine, according to the preset time, that the preset time is reached, according to the preset time And the preset duration, correcting the playing progress of the live channel.
The apparatus of claim 9 wherein said correcting module comprises:

a third determining unit, configured to determine a second time corresponding to the current playing position at the preset time;

a comparison unit, configured to compare a size relationship between the actual time difference between the preset time and the second time and the preset duration;

The first processing unit is configured to speed up playing of the live channel according to the first preset policy if it is determined that the actual time difference is greater than the preset duration;

The second processing unit is configured to slow down the playing of the live channel according to the second preset policy if it is determined that the actual time difference is less than the preset duration.
The apparatus according to claim 10, wherein the first preset policy comprises: in the process of decoding the media file fragment, two non-adjacent I in the media file fragment Repeatingly discarding frames between frames; wherein, the B frames are preferentially discarded, and the P frames are discarded without the B frames; the number of discarded frames is at least based on the difference between the actual time difference and the preset duration The value is determined.
The apparatus according to claim 10, wherein the second preset policy comprises: performing a repeated play of a specific frame in the media file fragment; wherein the number of specific frames repeatedly played is at least according to the Determining, by the difference between the preset duration and the actual time difference, the specific frame includes at least one of the following: an I frame, a P frame, and a B frame.
A live channel playing system includes: a set top box, a content distribution network, and a time synchronization source, wherein

The content distribution network is connected to the set top box, and is configured to generate a media file fragment and an index file according to the live broadcast source, and provide the set top box with the download of the media file fragment and the update of the index file; The fragment file includes the fragmentation information of the media file fragment, where the fragmentation information includes: a start time of the media file fragmentation;

The set top box is configured to obtain an index file from the content distribution network, and parse the fragmentation information; obtain the fragment of the media file according to the fragmentation information; and determine the location based on the start time a playback position corresponding to the first time in the media file fragment; and from the playing The location starts to play the live channel; wherein, the time difference between the current time of the set top box and the first time is a preset duration;

The time synchronization source is respectively connected to the content distribution network and the set top box, and is set to synchronize the time of the set top box and the content distribution network.