WO2012083841A1

WO2012083841A1 - Method, terminal and system for changing channel

Info

Publication number: WO2012083841A1
Application number: PCT/CN2011/084289
Authority: WO
Inventors: 周茂林
Original assignee: 中兴通讯股份有限公司
Priority date: 2010-12-20
Filing date: 2011-12-20
Publication date: 2012-06-28
Also published as: CN102547448B; CN102547448A

Abstract

The present invention relates to a method, terminal and system for changing channel. The method includes: a play terminal sends a declaration message in a local area network, so as to obtain a list of cache terminals which can provide channel program content service; and the play terminal changes the channel via a cache terminal in the list of cache terminals when the play terminal receives a play command for changing channel. The present invention is based on the SSDP protocol of UPnP, and the play terminal quickly receives a code stream of the channel program from the cache terminal which provides the service so as to start the playing, which increases the speed of channel changing and improves the quality of service of IPTV. At the same time, no superfluous media packets will be sent to the play terminal by the cache terminal, so that a seamless handover between media receiving methods can be achieved without wasting network resources. Moreover, the present invention can also realize the function of re-sending lost packets, thereby reducing the dependence of IPTV on the network quality and improving the video quality for the user in case of packet loss.

Description

Channel switching method, terminal and system

The present invention relates to the field of network multimedia technologies, and in particular, to a channel switching method, a terminal, and a system. Background technique

The media transmitted in Internet Protocol Television (IPTV) generally uses video and audio compression coding algorithms. The pictures (ie, frames) are divided into I frames, P frames, and B frames. The I frame is an internally coded frame, which is the whole. The frame is completely encoded; the P frame and the B frame record changes relative to the I frame. Without an I frame, P and B frames cannot be decoded. The user can cut into the channel at any time point of the length of the GOP (Group of Pictures). Since the set-top box needs to receive the video after receiving the first complete I frame, the set-top box receives the content of a complete I-frame program. The video content cannot be displayed within the receiving time, which is the main reason that the random access point (RAP, Random Access Point) causes the channel switching speed to be slow. In theory, the denser the I frame, the more likely the set-top box will receive the full I frame after entering the channel, and the faster the switching channel speed, but this will increase the code rate of the program and consume more bandwidth resources. Therefore, it is only considered to increase the density of I frames, which is not practical.

In order to improve the channel switching speed, the existing channel switching schemes include: Deploying a channel fast-transmitting server in the network, specifically for buffering the latest channel media data. When the set-top box receives the channel play command, it requests the media data of the corresponding channel to the fast-transmitting server, and the fast-transmitting server sends the channel program content starting with the I frame to the set-top box through the unicast mode, and generally the sending speed is higher than the normal code at the beginning stage. The rate is fast, so that the set top box can quickly display the video picture. When the channel fast transmission data and the channel normal data are synchronized, the set top box completely switches to the normal channel access mode receiving medium, and stops acquiring data from the fast sending server. However, adding a fast-forward server to achieve fast switching of channels requires consideration of concurrency time and higher system performance requirements, thereby increasing operating costs. Summary of the invention

The main object of the present invention is to provide a channel switching method, terminal and system, which aim to improve the quality of IPTV service.

In order to achieve the above object, the present invention provides a channel switching method, where the method includes: a playback terminal transmitting a announcement message in a local area network to obtain a list of cache terminals that can provide a channel program content service;

When the playing terminal receives the channel switching play command, the channel switching is performed by the cache terminal in the cache terminal list.

Preferably, the channel switching by using the cache terminal in the cache terminal list includes: the playback terminal sending a request for acquiring the content of the destination channel program to one or more cache terminals in the cache terminal list;

Receiving, by the cache terminal, a destination channel program content cache starting with an I frame; receiving a notification message sent by the cache terminal after the destination channel program content cache sent by the cache terminal is synchronized with the channel multicast medium;

And adding the channel media packet delivered by the channel multicast group to the channel multicast group according to the notification message, and sending the received first channel media packet to the cache terminal;

And when the destination channel program content buffer sent by the cache terminal is connected to the channel media packet received by the play terminal from the channel multicast group, the target channel program content is obtained from the channel multicast group.

Preferably, the playing terminal selects a corresponding cache terminal according to a network minimum ping value of the cached terminal in the cached terminal list or according to a sequence of receiving the cached terminal response message.

The invention also provides a channel switching method, the method comprising:

The buffer terminal buffers the channel program content when receiving the multicast code stream for channel playback; Receiving a response message that can provide a channel program content service to the playback terminal when receiving the announcement message sent by the playback terminal;

When receiving the request for acquiring the content of the target channel program sent by the playing terminal, the channel switching is performed for the playing terminal by means of unicast.

Preferably, the performing channel switching for the playing terminal by means of unicasting comprises: sending, to the playing terminal, a destination channel program content cache starting with an I frame at a controllable code rate;

After the content channel of the target channel is synchronized with the channel multicast media, the broadcast terminal is notified to join the channel multicast group, and the first channel media packet from the channel multicast group sent by the play terminal is received;

And when the sent content channel cache of the destination channel is connected with the channel media packet received by the play terminal from the channel multicast group, stopping sending the target channel program content cache to the play terminal.

Preferably, the cache terminal matches the program content by sending or when the channel program is

In the RTP encapsulation, the RTP header number is the same to determine that the channel program content buffer sent by the cache terminal is synchronized with the channel multicast medium.

The present invention also provides a channel switching terminal, where the channel switching terminal includes:

a cache terminal list obtaining module, configured to send an announcement message in the local area network to obtain a cache terminal list that can provide a channel program content service;

The first channel switching module is configured to perform channel switching by using the cache terminal in the cache terminal list when the play terminal receives the channel switching play command.

Preferably, the first channel switching module includes:

a requesting unit, configured to send, to the one or more cache terminals in the cache terminal list, a request for acquiring content of a target channel program;

a buffer receiving unit, configured to receive a destination channel that is sent by the cache terminal and starts with an I frame Program content cache;

a notification message receiving unit, configured to receive a notification message sent by the cache terminal after the destination channel program content cache and the channel multicast media are synchronized by the cache terminal;

The media packet receiving and sending unit is configured to join the channel multicast group according to the notification message, start receiving the channel media packet delivered by the channel multicast group, and send the received first channel media packet to the cache terminal. ;

a channel switching unit, configured to: when the destination channel program content buffer sent by the cache terminal is connected to the channel media packet received by the play terminal from the channel multicast group, acquire a target channel program from the channel multicast group content.

a cache module, configured to cache channel program content when receiving a multicast stream for channel playback;

a response message sending module, configured to return, to the playing terminal, a response message that can provide a channel program content service when receiving the announcement message sent by the playing terminal;

The second channel switching module is configured to perform channel switching for the playing terminal by using a unicast manner when receiving the request for acquiring the content of the target channel program sent by the playing terminal.

Preferably, the second channel switching module includes:

a buffer sending unit, configured to send, to the playing terminal, a destination channel program content cache starting with an I frame at a controllable code rate;

a notification sending and media packet receiving unit, configured to notify the playing terminal to join the channel multicast group after the target channel program content cache is synchronized with the channel multicast media, and receive the channel group sent by the playing terminal The first channel media package of the broadcast group;

a control unit, configured to stop sending the target channel program content cache to the play terminal when the sent target channel program content cache is connected with the channel media package received by the play terminal from the channel multicast group . Preferably, the cached terminal matches the content of the program transmitted by the cache terminal, or when the channel program is encapsulated by the RTP, the channel program content cache sent by the cache terminal is synchronized with the channel multicast media by using the same RTP header number.

The present invention also provides a channel switching system, where the channel switching system includes: a playing terminal and a cache terminal, wherein:

The play terminal is configured to send an announcement message in a local area network to obtain a cache terminal list that can provide a channel program content service; when the play terminal receives a channel switch play command, perform a channel through the cache terminal in the cached terminal list. Switch

The cache terminal is configured to buffer a channel program content when receiving a multicast code stream for channel playback; and return a response that provides a channel program content service to the play terminal when receiving the announcement message sent by the play terminal a message: when receiving the request for acquiring the content of the target channel program sent by the playing terminal, performing channel switching for the playing terminal by means of unicast.

Preferably, the playing terminal is further configured to send a packet loss retransmission request to the cache terminal when detecting a packet loss during the program playing;

The cache terminal is further configured to receive the packet loss retransmission request, and retransmit the packet loss to the play terminal according to the retransmission request.

The channel switching method, the terminal and the system provided by the present invention, through a UPnP-based Simple Service Discovery Protocol (SSDP), discover a cache terminal that can provide a channel program content service in the network, and receive a channel switching. After the command, the playing terminal quickly receives the channel program code stream from the cache terminal providing the service to start playing, thereby speeding up the channel switching speed and improving the IPTV service quality. DRAWINGS

1 is a schematic flow chart of an embodiment of a channel switching method according to the present invention;

2 is a schematic diagram of a cache end in a cache terminal list according to an embodiment of the channel switching method of the present invention. Schematic diagram of the process of channel switching;

3 is a schematic flow chart of another embodiment of a channel switching method according to the present invention;

4 is a schematic flowchart of channel switching for a playback terminal in a unicast manner according to another embodiment of the channel switching method of the present invention;

FIG. 5 is a schematic structural diagram of an embodiment of a channel switching terminal according to an embodiment of the present invention; FIG.

6 is a schematic structural diagram of a first channel switching module in an embodiment of a channel switching terminal according to the present invention;

7 is a schematic structural diagram of another embodiment of a channel switching terminal according to the present invention;

8 is a schematic structural diagram of a second channel switching module in another embodiment of the channel switching terminal of the present invention;

FIG. 9 is a schematic structural diagram of an embodiment of a channel switching system according to the present invention. detailed description

In order to make the technical solutions of the present invention clearer and clearer, the following will be further reviewed in conjunction with the accompanying drawings.

The solution of the embodiment of the present invention is mainly based on the SSDP protocol of the universal plug and play (UpnP), and the playback terminal sends an announcement message in the local area network to obtain a list of cache terminals that can provide the channel program content service; When the channel switching play command is performed, the channel switching is performed by the cache terminal in the cache terminal list, and the play terminal quickly receives the channel program code stream from the cache terminal providing the service to start playing, thereby speeding up the channel switching speed.

As shown in FIG. 1 , an embodiment of the present invention provides a channel switching method, where the method includes: Step S101: A playback terminal sends an announcement message in a local area network to obtain a cache terminal list that can provide a channel program content service;

In this embodiment, the announcement message specifically uses the UPnP SSDP announcement message.

UPnP is an application layer technology standard designed for peer-to-peer interconnection in the local area network. It is designed to provide IP-based technology for homes, small businesses, and public places. The network service auto-discovery mechanism used.

SSDP is used for service discovery, whereby the control point can locate the resources of its interest in the network, and the device can inform their availability. The SSDP client (control point) can send a Discovery message to the SSDP port (239.255.255.250: 1900) of the locally reserved multicast address to find the SSDP service; the SSDP service (device) can also send the SSDP indication in the same way to announce its existence.

After the playback terminal is started, the UPnP SSDP announcement message is sent in the local area network, and the list of cached terminals that can provide the channel program content service is found, and the table is maintained.

The buffer terminal needs to perform channel program content buffering when performing channel playing and receiving the multicast stream, and at least one complete GOP is buffered, and the buffer terminal in the multicast channel playing state (receiving the multicast program stream) can provide the channel program. The content service can respond to the announcement message sent by the playback terminal.

Step S102: When the play terminal receives the channel switching play command, perform channel switching by using the cache terminal in the cache terminal list.

When the playing terminal receives the channel switching play command, one or more cache terminals capable of providing the channel program content service are selected from the cache terminal list, and the destination channel program content is requested.

After receiving the request for the content of the destination channel program sent by the terminal, the cache terminal transmits the content of the target channel at a faster rate than the normal rate of the program, and the content of the program starts from the I frame; the content channel of the program channel and the channel of the destination channel that the cache terminal transmits After the multicast media is synchronized, the broadcast terminal is notified to join the channel multicast group; the media of the cache terminal continues to be sent, and the rate is smaller or the same as the normal rate of the program; after the channel is joined to the channel multicast group, the broadcast terminal starts to receive the channel multicast group. The media packet, and the first one received is sent to the cache terminal; to prevent the cache terminal from transmitting the redundant duplicate destination channel program content to the playback terminal.

When the media information sent by the cache terminal and the multicast group media information received by the playback terminal can be connected, the content of the target channel program is stopped from being sent to the playback terminal. As shown in FIG. 2, the step of performing channel switching by using the cache terminal in the cache terminal list in step S102 includes:

Step S1021: The playback terminal sends a request for acquiring the content of the target channel program to one or more cache terminals in the cache terminal list.

Step S1022: Receive, by the cache terminal, a destination channel program content cache starting with an I frame;

If there are multiple cache terminals providing the content of the target channel program, the playback terminal may receive the response of the first cached terminal, and notify other terminals to stop sending the program cache of the destination channel.

Step S1023: Receive a notification message sent by the cache terminal after the content channel cache of the destination channel that it sends is synchronized with the channel multicast media.

Step S1024, adding a channel multicast group according to the notification message, starting to receive the channel media packet delivered by the channel multicast group, and sending the received first channel media packet to the cache terminal;

Step S1025: When the content channel cache of the destination channel sent by the cache terminal is connected to the channel media packet received by the broadcast terminal from the channel multicast group, the content of the target channel program is obtained from the channel multicast group.

In this embodiment, the play terminal may select a corresponding cache terminal according to the network minimum ping value of the cached terminal in the cached terminal list or according to the order in which the cached terminal response message is received.

Determining the manner in which the cache terminal transmits the destination channel program content cache and the channel multicast media, and the program content may be consistently matched or the channel program may be transmitted in real time.

(RTP, Real-time Transport Protocol) When the RTP header number is the same, it is determined that the channel program content buffer sent by the cache terminal is synchronized with the channel multicast medium.

It should be noted that, in this embodiment, the cache terminal and the play terminal may be the same type of terminal, such as a set top box, or may not be the same type of terminal, for example, the play terminal is a set top box, and the cache terminal is a personal computer (PC, Personal Computer). Wait. For example, when a set-top box performs channel switching and enters channel playback, if another set-top box is already playing the channel program, the channel program content required on the previous set-top box can be obtained from the next set-top box that has already played the channel program. Media data does not need to be sent from a dedicated fast delivery server.

Further, the rate at which the cache terminal sends the content channel program content cache to the playback terminal is generally faster than the normal code rate. Otherwise, the content channel cache of the destination channel sent by the cache terminal cannot be synchronized with the media content sent by the channel multicast group, because The cache terminal continues to receive channel content.

In a practical application, the packet loss retransmission function can also be implemented according to the method in this embodiment.

Specifically, the cache terminal may provide a packet loss retransmission function. If the play terminal detects a packet loss during the program play, the broadcast terminal may request a packet loss retransmission from the cache terminal. After receiving the packet loss retransmission request sent by the broadcast terminal, the cache terminal retransmits the packet loss to the playback terminal according to the retransmission request. This can reduce the dependence of IPTV on network quality and improve the video quality of users in the case of packet loss. The cost of the network, the playback terminal can display the video picture as soon as possible by the cache terminal in the cached terminal list. When the fast-transmitted media buffer synchronizes with the channel multicast group to send the media information, the switch to the normal channel multicast play state is shortened. Channel switching time improves IPTV service quality and improves user satisfaction.

As shown in FIG. 3, another embodiment of the present invention provides a channel switching method, where the method includes:

Step S301: The buffer terminal caches the content of the channel program when receiving the multicast code stream for channel playback.

The buffer terminal needs to perform channel program content buffering when performing channel play to receive the multicast code stream, and at least caches a complete GOP, and is in a multicast channel playing state (receiving a multicast section) The cache terminal of the destination stream stream can provide the channel program content service, and all can respond to the announcement message sent by the playback terminal.

Step S302, when receiving the announcement message sent by the playback terminal, returning a response message to the playback terminal that can provide the channel program content service;

The cache terminal listens to the running status of the playing terminal in the local area network through the simple service discovery protocol in UPnP, and gives a response when the playing terminal issues an SSDP notification message, informing the playing terminal that the target channel program content service can be provided.

Step S303: When receiving the request for acquiring the content of the target channel program sent by the playing terminal, performing channel switching for the playing terminal by using a unicast manner.

After receiving the request from the playing terminal, the buffering terminal sends the media buffer starting with the I frame to the playing terminal at a controllable bit rate in a unicast manner, that is, the destination channel program content cache in the embodiment. At the same time, the content of the channel program that informs other terminals to provide the cache service by the announcement message has changed. When the cache terminal is shut down, it also needs to send a message to notify other terminals that the service cannot be provided.

After the content of the cached program sent by the channel buffering terminal is synchronized with the channel multicast content, the channel playing terminal is notified to join the multicast group; meanwhile, the channel buffering terminal continues to send the channel program content buffer at a synchronous or slower rate of the channel program content.

The content of the cached program sent by the channel buffer terminal and the channel multicast content can be determined by matching the content of the transmitted program, or can be judged by the RTP header number, etc., when the program content is consistent, or the RTP serial number is the same, then the two are considered Synchronize.

For example, assuming that the normal code rate of the program is constant at 2 M bps, the code rate of the cache terminal is 2.2 M bps, which is 1/10 larger than the normal code rate. When receiving the fast request from the playback terminal, the cache terminal buffers the data of 0.5s. By calculation, the content of the target channel program that should be sent by the cache terminal after 5s can be synchronized with the content of the channel program sent by the multicast group, and the cache terminal sends the content. The program content to the playback terminal should be the content of the multicast group channel program newly received by the channel buffer terminal. At this point, the cache terminal notification The channel playing terminal can join the multicast group and still need to continue to send the channel program content. At this time, the code rate sent by the cache terminal is obviously 2M, and may be less than 2M.

After the playing terminal joins the multicast group, the media content sent by the channel multicast group is received; when the playing terminal receives the first channel media packet, the media packet is immediately sent to the cache terminal. After receiving the media packet information sent by the playing terminal, the cache terminal continues to send the content channel content cache of the destination channel until the content channel buffer of the transmitted destination channel and the media packet received by the playing terminal can be connected.

When the channel program is encapsulated by RTP, the first channel media packet received by the playback terminal may refer to the sequence number of the first multicast RTP packet received, or other information used to identify the load of the media program.

For example, after the play terminal joins the multicast group, the first RTP packet sequence number received by the play terminal is 100. After the cache terminal receives the message, the RTP sequence number of the last packet of the sent channel program content may be 99, so that the play The content of the program received by the terminal from the cache terminal and the content of the program received from the multicast group can be connected. Of course, the last packet sequence number sent by the cache terminal can also be 100. The basic principle is to ensure that at least the content of the two parts can be connected, and to minimize the duplication of the content of the two parts of the media program.

When the destination channel program buffer received by the playback terminal and the multicast group data can be connected, the playback to the full multicast mode is performed.

As shown in FIG. 4, the step of performing channel switching for the play terminal by means of unicast in step S303 includes:

Step S3031: Send, to the playing terminal, a destination channel program content cache starting with an I frame at a controllable code rate;

Step S3032: After the destination channel program content cache is synchronized with the channel multicast media, notify the broadcast terminal to join the channel multicast group, and receive the first channel media package from the channel multicast group sent by the play terminal;

Step S3033, when the destination channel program content is buffered and the playback terminal is from the channel multicast group. When the received channel media package is connected, the transmission of the destination channel program content cache to the playback terminal is stopped. In this embodiment, the playback terminal obtains the cache terminal list that provides the destination channel program content service, and obtains the desired program content from the cache terminal in the list to play to the user to complete the channel switching, thereby shortening the channel switching time. At the same time, after receiving the media packet sent by the multicast group, the playback terminal immediately sends the packet information to the cache terminal, so that the cache terminal does not send the excess media packet to the playback terminal, and the network resource is not wasted. Seamless switching of media reception methods.

As shown in FIG. 5, an embodiment of the present invention provides a channel switching terminal, including: a cache terminal list obtaining module 501, and a first channel switching module 502, where:

The cached terminal list is 501, configured to send an announcement message in the local area network to obtain a list of cached terminals that can provide the channel program content service;

UPnP is an application layer technology standard designed for peer-to-peer interconnection in the local area network. It is designed to provide IP-based, easy-to-use automatic discovery mechanism for network services for homes, small businesses, and public places. .

The Simple Service Discovery Protocol (SSDP) is used for service discovery, whereby the control point can locate the resources of its interest in the network, and the device can inform their availability. The SSDP client (control point) can send a Discovery message to the SSDP port (239.255.255.250: 1900) of the locally reserved multicast address to find the SSDP service; the SSDP service (device) can also send the SSDP indication in the same way to announce its existence.

After the playback terminal is started, the cached terminal list is sent to the UPnP SSDP announcement message in the local area network, and the list of cached terminals that can provide the channel program content service is found, and the table is maintained.

The first channel switching module 502 is configured to perform channel switching by buffering the buffer terminal in the terminal list when the playing terminal receives the channel switching play command.

When the playing terminal receives the channel switching play command, the first channel switching module 502 selects one or more cache terminals capable of providing the channel program content service from the cache terminal list, and requests the destination channel program content.

When the media information sent by the cache terminal and the multicast group media information received by the playback terminal can be connected, the content of the target channel program is stopped from being sent to the playback terminal.

As shown in FIG. 6, the first channel switching module 502 includes: a requesting unit 5021, a buffer receiving unit 5022, a notification message receiving unit 5023, a media packet receiving and transmitting unit 5024, and a channel switching unit 5025, where:

The requesting unit 5021 is configured to send, to the one or more cache terminals in the cached terminal list, a request for acquiring the content of the target channel program;

The buffer receiving unit 5022 is configured to receive a destination channel program content cache that is sent by the cache terminal and starts with an I frame.

The notification message receiving unit 5023 is configured to receive a notification message that is sent by the cache terminal after the destination channel program content cache and the channel multicast media are synchronized by the cache terminal; The media packet receiving and sending unit 5024 is configured to join the channel multicast group according to the notification message, start receiving the channel media packet delivered by the channel multicast group, and send the received first channel media packet to the cache. terminal;

The channel switching unit 5025 is configured to obtain the target channel program content from the channel multicast group when the destination channel program content buffer sent by the buffer terminal is connected to the channel media packet received by the playing terminal from the channel multicast group.

As shown in FIG. 7, another embodiment of the present invention provides a channel switching terminal, including: a cache module 701, a response message sending module 702, and a second channel switching module 703, where:

The cache module 701 is configured to cache the channel program content when receiving the multicast code stream for channel playback;

The cache terminal needs to cache the channel program content through the cache module 701 when performing channel play to receive the multicast code stream, and at least cache a complete GOP, and the cache terminal in the multicast channel play state (receiving the multicast program code stream) The channel program content service can be provided, and all the announcement messages sent by the playing terminal can be responded to.

The response message sending module 702 is configured to: when receiving the announcement message sent by the playing terminal, return a response message that can provide the channel program content service to the playing terminal;

The buffer terminal response message sending module 702 listens to the running status of the playing terminal in the local area network through the simple service discovery protocol in the UPnP, and gives a response when the playing terminal issues the SSDP notification message, and informs the playing terminal that the target channel program content service can be provided.

The second channel switching module 703 is configured to perform channel switching for the playing terminal by using a unicast manner when receiving a request for acquiring the content of the target channel program sent by the playing terminal.

After the buffering terminal receives the request of the playing terminal, the second channel switching module 703 sends the media buffer starting from the I frame to the playing terminal at a controllable bit rate in a unicast manner, that is, the purpose as described in this embodiment. Channel program content cache. At the same time, the content of the channel program that informs other terminals to provide the cache service by the announcement message has changed. The message needs to be sent out when the cache terminal is shut down. Notify other terminals that the service is no longer available.

For example, suppose the normal code rate of the program is constant at 2M bps, and the code rate of the cache terminal is 2.2M bps, which is 1/10 larger than the normal code rate. When receiving the fast request from the playback terminal, the cache terminal buffers the data of 0.5s. By calculation, the content of the target channel program that should be sent by the cache terminal after 5s can be synchronized with the content of the channel program sent by the multicast group, and the cache terminal sends the content. The program content to the playback terminal should be the content of the multicast group channel program newly received by the channel buffer terminal. At this time, the cache terminal notifies the channel playing terminal that it can join the multicast group, and still needs to continue to send the channel program content. At this time, the code rate sent by the cache terminal is obviously 2M, which is also less than 2M.

For example, after the play terminal joins the multicast group, the first RTP packet sequence number received by the play terminal is 100. After the cache terminal receives the message, the RTP sequence number of the last packet of the sent channel program content may be 99, so that the play The content of the program received by the terminal from the cache terminal and the content of the program received from the multicast group can be connected. Of course, the last packet number sent by the cache terminal can also be So it is 100. The basic principle is to at least ensure that the content of the two parts can be connected, and to minimize the duplication of the content of the two parts of the media program.

As shown in FIG. 8, the second channel switching module 703 includes: a buffer sending unit 7031, a notification sending and media packet receiving unit 7032, and a control unit 7033, where:

a buffer sending unit 7031, configured to send, to the playing terminal, a destination channel program content cache starting with an I frame at a controllable code rate;

The notification sending and media packet receiving unit 7032 is configured to notify the playing terminal to join the channel multicast group after the destination channel program content buffer is synchronized with the channel multicast medium, and receive the first channel from the channel multicast group sent by the playing terminal. Media package

The control unit 7033 is configured to stop sending the target channel program content cache to the playing terminal when the transmitted destination channel program content buffer is connected to the channel media packet received by the playing terminal from the channel multicast group.

As shown in FIG. 9, an embodiment of the present invention provides a channel switching system, including: a playback terminal 901 and a cache terminal 902, where:

The play terminal 901 is configured to send a announcement message in the local area network to obtain a cache terminal list that can provide a channel program content service; when the play terminal 901 receives the channel switch play command, perform channel switching by using the cache terminal 902 in the cache terminal list;

The buffer terminal 902 is configured to buffer the channel program content when receiving the multicast code stream for channel play, and return a response message for providing the channel program content service to the play terminal 901 when receiving the announcement message sent by the play terminal 901. When receiving the request for acquiring the content of the destination channel program sent by the playback terminal 901, the channel switching is performed for the playback terminal 901 by means of unicast.

Further, the playing terminal 901 is further configured to detect, when the packet is lost during the program playing, to The cache terminal 902 sends a packet loss retransmission request;

The cache terminal 902 is further configured to receive a packet loss retransmission request, and retransmit the lost packet to the play terminal 901 according to the retransmission request.

Specifically, the cache terminal 902 can provide a packet loss retransmission function, and if the play terminal 901 detects a packet loss during the program play, the buffer terminal 902 can request a packet loss retransmission. After receiving the packet loss retransmission request sent by the play terminal 901, the cache terminal 902 retransmits the lost packet to the play terminal 901 according to the retransmission request. This can reduce the dependence of IPTV on network quality and improve the video quality of users in the case of packet loss.

Compared with the prior art method of adding a fast-speed server to implement fast switching of channels, it is necessary to consider the concurrency time, and the system performance is high, which causes an increase in operating costs. In this embodiment, the UPDP-based SSDP protocol is used, and the playback terminal is in the local area network. Sending an announcement message to obtain a cache terminal list that can provide a channel program content service; when the playback terminal receives the channel switching play command, performing channel switching by buffering the cache terminal in the terminal list, the play terminal quickly receives the cached terminal from the service providing terminal The channel program stream starts playing, which speeds up the channel switching speed and improves the user experience quality. In the embodiment of the present invention, the cache terminal can provide the packet loss retransmission function. When the broadcast terminal detects the packet loss during the program play, the playback terminal can request the cache terminal to implement the packet loss retransmission, thereby reducing the network quality of the IPTV. Dependency improves the video quality of users in the case of packet loss.

The above is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and equivalent structural or process changes made by the present specification and drawings may be directly or indirectly applied to other related technical fields. The same is included in the scope of patent protection of the present invention.

Claims

Claim

A channel switching method, the method comprising:

The playback terminal sends an announcement message in the local area network to obtain a list of cache terminals that can provide channel program content services;

The method according to claim 1, wherein the performing channel switching by using the cache terminal in the cache terminal list comprises:

The playback terminal sends a request for acquiring the content of the destination channel program to one or more cache terminals in the cache terminal list;

The method according to claim 2, wherein the playing terminal selects a corresponding cache according to a network of the cached terminal in the cached terminal list, a ping value, or a sequence of receiving a response message of the cached terminal. terminal.

A channel switching method, characterized in that the method comprises:

The buffering terminal buffers the channel program content when receiving the multicast code stream for channel playback; and when receiving the announcement message sent by the playback terminal, returns a response message to the playback terminal that can provide the channel program content service; When receiving the request for acquiring the content of the target channel program sent by the playing terminal, the channel switching is performed for the playing terminal by means of unicast.

The method according to claim 4, wherein the performing channel switching for the playing terminal by means of unicasting comprises:

Sending, to the playing terminal, a destination channel program content cache starting with an I frame at a controllable code rate;

The method according to claim 5, wherein the buffering terminal determines that the program content is consistently transmitted or when the channel program is encapsulated by the real-time transport protocol RTP, and the cache terminal is sent by using the same RTP header number. The channel program content cache is synchronized with the channel multicast media.

A channel switching terminal, wherein the channel switching terminal comprises: a cache terminal list obtaining module, configured to send an announcement message in a local area network to obtain a cache terminal list that can provide a channel program content service;

The terminal according to claim 7, wherein the first channel switching module comprises:

a requesting unit, configured to send, to the one or more cache terminals in the cached terminal list, a request for acquiring content of a destination channel program; a buffer receiving unit, configured to receive a destination channel program content cache that is sent by the cache terminal and starts with an I frame;

A channel switching terminal, the channel switching terminal includes: a buffering module, configured to cache a channel program content when receiving a multicast code stream for channel playback;

The terminal according to claim 9, wherein the second channel switching module comprises:

a control unit, configured to cache, when the destination channel program content is sent, and the playing terminal When the channel media packet received from the channel multicast group is connected, the transmission of the destination channel program content cache to the playback terminal is stopped.

The terminal according to claim 9 or 10, wherein the buffering terminal matches the content of the program to be transmitted, or when the channel program is encapsulated by RTP, the RTP header number is the same to determine the sending by the cache terminal. The channel program content cache is synchronized with the channel multicast media.

12. A channel switching system, wherein the channel switching system comprises: a playback terminal and a cache terminal, wherein:

13. The system of claim 12, wherein

The playing terminal is further configured to send a packet loss retransmission request to the cache terminal when detecting a packet loss during the program playing;