Channel changing method, apparatus, and system

A channel changing server having a processor, comprising:

• a recording module, configured to record in real time a timestamp of a media packet of a multicast media stream which enters a buffer, and a key frame which enters the buffer;
• a timestamp obtaining module, configured to, when a channel changing request transmitted by a terminal has been detected, obtain, according to the recorded timestamp, a first timestamp of a media packet which is of a target channel and enters the buffer at a channel changing request moment, and a second timestamp of a media packet in which a key frame which is of the target channel and is the last to enter the buffer before the channel changing request moment is located;
• a timestamp difference determining module, configured to determine a timestamp difference between the first timestamp and the second timestamp by the processor;
• a transmitting module, configured to transmit the timestamp difference to the terminal, and starting from the key frame, transmitting, in a unicast manner, a burst media stream of the target channel in the buffer to the terminal;
• wherein the timestamp difference is used for the terminal to rectify a timestamp of a media packet in a media stream which is received after the channel changing request moment, and the media stream which is received after the channel changing request moment comprises the burst media stream.

A channel changing system, comprising:

• a channel changing server and a terminal, wherein the terminal is configured to transmit a channel changing request to the channel changing server wherein the channel changing request carries information of a target channel;
• the channel changing server is configured to record in real time a timestamp of a media packet of a multicast media stream which enters a buffer, and a key frame which enters the buffer;
• when a channel changing request transmitted by a terminal has been detected, obtain a first timestamp of a media packet which is of a target channel and enters the buffer at a channel changing request moment, and a second timestamp of a media packet in which a key frame which is of the target channel and is the last to enter the buffer before the channel changing request moment is located;
• determine a timestamp difference between the first timestamp and the second timestamp;
• and transmit the timestamp difference to the terminal, and starting from the key frame, transmit, in a unicast manner and to the terminal, a burst media stream of the target channel in the buffer to the terminal;
• the terminal if further configured to receive the timestamp difference sent by the channel changing server, and rectify a timestamp of a media packet of a media stream which is received after the channel changing request moment, and the media stream which is received after the channel changing request moment comprises the burst media stream.