Method and system for inhibiting audio-video synchronization delay

1. A method for accelerating the start of display of an interleaved audio-video data, the method comprising:

in a server for providing interleaved audio-video data to a decoder, the server configured to be communicatively coupled to an Internet Protocol (IP) network, receiving a command to switch the decoder to receiving a stream in progress, comprising a single stream of multiplexed data in which audio and video data are interleaved;

in the server, responsively to the command, collecting audio and video data of the stream in progress;

in the server, generating a modified single stream of interleaved audio and video data, the modified stream comprising audio and video access units of the collected data of the stream in progress, wherein a plurality of the access units are repositioned in the modified single stream of interleaved audio and video data such that an audio access unit and a video access unit that correlate in time to one another are positioned closer to one another in the modified single stream than in the stream in progress, the generating of the modified single stream further comprising discarding collected audio access units which correspond to video access units that were transmitted earlier than a beginning of the modified single stream; and

providing the modified single stream from the server, rather than the stream in progress, to the decoder via the IP network.

2. The method as claimed in claim 1 , wherein the generating of the modified single stream comprises repositioning audio access units closer to video access units that correlate in time to the repositioned audio access units.

3. The method as claimed in claim 1 , wherein the generating of the modified single stream comprises repositioning video access units closer to audio access units that correlate in time to the repositioned video access units.

4. The method as claimed in claim 1 , wherein providing the modified single stream to the decoder comprises providing interleaved audio-video data at a rate which is faster than a nominal rate of the interleaved audio-video data.

5. The method as claimed in claim 1 , the generating of the modified single stream comprising discarding collected audio access units or video access units, by performing an action selected from the group of actions consisting of: rewriting over, silencing, and removing.

6. The method as claimed in claim 1 , wherein providing the modified single stream comprises transmitting the modified single stream in a unicast mode for a determined period of time before reconnecting to a multicast service providing the stream in progress.

7. The method as claimed in claim 6 , wherein transmitting the modified single stream in a unicast mode for a determined period of time comprises providing the modified single stream accelerated until the accelerated stream catches up with the multicast service.

8. A computer program product stored on a non-transitory tangible computer readable storage medium for accelerating the start of viewing an interleaved audio video stream, the computer product comprising computer useable program code which, when executed by one or more processors in a server for providing interleaved audio-video data to a decoder, the server configured to be communicatively coupled to an Internet Protocol (IP) network, cause the one or more processors to perform steps of:

receiving a command to switch the decoder to receiving a stream in progress, comprising a single stream of multiplexed data in which audio and video data are interleaved;

responsively to the command, collecting audio and video data of the stream in progress;

generating a modified single stream of interleaved audio and video data, the modified single stream comprising audio and video access units of the collected data of the stream in progress, wherein a plurality of the access units are repositioned in the modified single stream of interleaved audio and video data such that an audio access unit and a video access unit that correlate in time to one another are positioned closer to one another in the modified single stream than in the stream in progress, the generating of the modified single stream comprising discarding collected audio access units which correspond to video access units that were transmitted earlier than a beginning of the modified single stream; and

providing the modified single stream from the server, rather than the stream in progress, to the decoder via the IP network.

9. The computer program product as claimed in claim 8 , wherein the generating of the modified single stream comprises repositioning audio access units closer to a one or more video access units located at a beginning of the modified single stream.

10. The computer program product as claimed in claim 8 , wherein the discarding of the collected audio access units comprises an action selected from the group of actions consisting of: rewriting over, and silencing.

11. The computer program product as claimed in claim 8 , used for switching between a first channel and a second channel of a multicast service of which the second channel transmits the stream in progress, the computer program product comprising computer usable program code for transmitting the modified single stream of the second channel in a unicast mode for a determined period of time before resuming the multicast service.

12. The computer program product as claimed in claim 11 , comprising computer usable program code for providing the modified single stream of the second channel in a unicast mode until the modified single stream catches up with the stream in progress of the second channel of the multicast service.

13. A data processing system comprising:

a processor in a server for providing interleaved audio-video data to a decoder, the server configured to be communicatively coupled to an Internet Protocol (IP) network; and

a computer-readable storage medium, configured to be accessed by the processor, comprising a stored set of instructions for accelerating the start of viewing an interleaved audio video stream, whereby the processor is adapted to perform steps of:

receiving a command to switch the decoder to receiving a stream in progress, comprising a single stream of multiplexed data in which audio and video data are interleaved;

responsively to the command, collecting audio and video data of the stream in progress;

generating a modified single stream of interleaved audio and video data, the modified single stream comprising audio and video access units of the collected data of the stream in progress, wherein a plurality of the access units are repositioned in the modified single stream of interleaved audio and video data such that an audio access unit and a video access unit that correlate in time to one another are positioned closer to one another in the modified single stream than in the stream in progress, wherein the generating of the modified single stream comprises discarding collected audio access units which correspond to video access units that were transmitted earlier than a beginning of the modified single stream; and

providing the modified single stream from the server, rather than the stream in progress, to the decoder via the IP network.

14. The data processing system as claimed in claim 13 , wherein the generating the modified single stream comprises repositioning audio access units closer to a one or more video access units located at a beginning of the modified single stream.

15. The data processing system as claimed in claim 13 , wherein the discarding of the collected audio access units comprises an action selected from the group of actions consisting of: rewriting over, and silencing.

16. The data processing system as claimed in claim 13 , wherein the set of instructions includes instructions to include in the modified single stream collected audio access units having unchanged timing information with respect to the stream in progress.

17. The data processing system as claimed in claim 13 , for switching between a first channel and a second channel of a multicast service of which the second channel transmits the stream in progress, wherein the set of instructions includes instructions to transmit the modified single stream of the second channel in a unicast mode for a determined period of time before resuming the multicast service.

18. The data processing system as claimed in claim 17 , wherein the set of instructions includes instructions to provide the modified single stream of the second channel in a unicast mode until the modified single stream catches up with the stream in progress of the second channel of the multicast service.

19. The method as claimed in claim 1 , wherein the stream in progress comprises a stream in which audio units for display at respective specific times are located in the stream after video units for display after the respective specific times.

20. The method as claimed in claim 1 , wherein the receiving, collecting and repositioning are performed by a channel switch server separate from the decoder.