Techniques to perform rate matching for multimedia conference calls

1. A method, comprising:

receiving a set of video information with a first number of video frames from a first client terminal in a conference call, the set of video information for a current speaker of the conference call;

receiving a video bit rate for said set of video information;

receiving a bandwidth estimate for a media communications channel with a second client terminal in said conference call; and

calculating a second number of video frames to remove from said set of video information based on said video bit rate, said bandwidth estimate, a video frame type and a number of frames for said frame type.

2. The method of claim 1 , comprising calculating said second number based on a defined structure for said set of video information, said defined structure including multiple video frame types and a frame ordering sequence.

3. The method of claim 1 , comprising:

receiving a set of input parameters comprising a description of a frame type composition used in a group of picture structure, said video bit rate for said set of video information, a representative number of bits used for each frame type for said first number of video frames, and a frame ordering sequence; and

sending a set of output parameters comprising a remove frame type, a number of remove frames for said remove frame type, and a location for each remove frame in said set of video information, where said number and location of remove frames are calculated relative to said group of picture structure or relative to a pre-defined time window.

4. The method of claim 1 , comprising removing said second number of video frames from said set of video information in accordance with a set of output parameters.

5. The method of claim 1 , said bandwidth estimate to represent an instantaneous channel capacity for said media communications channel.

6. The method of claim 1 , said bandwidth estimate to represent changes in network conditions for said media communications channel.

7. The method of claim 1 , said bandwidth estimate to represent changes in media processing resources for a second client terminal to receive said video information.

8. The method of claim 1 , comprising sending said set of video information with a third number of video frames to a second client terminal over said media communications channel, with said third number of video frames to be less than said first number of video frames.

9. An apparatus, comprising:

a conferencing server; and

a rate matching module to adjust bit rates between media communications channels for client terminals in a conference call, said rate matching module to remove video frames from a group of pictures of a current speaker received on a first media communications channel to reduce a bit rate for said group of pictures, said rate matching module comprising:

a crossbar to receive said group of pictures, and identify a second media communications channel to communicate said group of pictures at said reduced bit rate; and

a rate matching calculator to receive a video bit rate for said group of pictures and a bandwidth estimate for said second media communications channel, and calculate a number of video frames to remove from said group of pictures based on said video bit rate, said bandwidth estimate, a video frame type and a number of frames for said frame type.

10. The apparatus of claim 9 , comprising said rate matching calculator to calculate said number of video frames to remove from said group of pictures based on a defined structure for said group of pictures, said defined structure including multiple video frame types and a frame ordering sequence.

11. The apparatus of claim 9 , comprising said rate matching calculator to receive a set of input parameters comprising a description of a frame type composition used in a group of picture structure, said video bit rate for said group of pictures, a number of bits used for each frame type for said first number of video frames, and a frame ordering sequence, said rate matching calculator to send a set of output parameters comprising a remove frame type, a number of remove frames for said remove frame type, and a location for each remove frame in said group of pictures.

12. The apparatus of claim 9 , comprising a traffic shaper to remove packets of the underlying transport protocol carrying said number of video frames from said group of pictures in accordance with a set of output parameters.

13. The apparatus of claim 9 , comprising a network interface to send said group of pictures over said second media communications channel at said reduced bit rate.

14. A multipoint control unit, comprising:

a first communications interface to receive a video bitstream at a video bit rate over a first media communications channel;

a rate matching module coupled to said first communications interface to selectively remove video frames from said video bitstream to reduce said bit rate; and

a second communications interface to send said video bitstream at said reduced bit rate over a second media communications channel;

wherein said rate matching module comprises:

a video crossbar to receive said video bitstream, and identify said second media communications channel to communicate said video bitstream at said reduced bit rate; and

a rate matching calculator to receive a video bit rate for said video bitstream and to receive a bandwidth estimate for said second media communications channel, and calculate a number of video frames to remove from said video bitstream based on said video bit rate, said bandwidth estimate, a video frame type and a number of frames for said frame type.

15. The multipoint control unit of claim 14 , comprising said rate matching calculator to receive a set of input parameters comprising a description of a frame type composition used in a group of picture structure, said video bit rate for said video bitstream, a number of bits used for each frame type of said video bitstream, and a frame dependency, said rate matching calculator to send a set of output parameters comprising a remove frame type, a number of remove frames for said remove frame type, and a location for each remove frame in said video bitstream, where said numbers and locations of video frames are calculated relative to said group of picture structure or a pre-defined time window.

16. The multipoint control unit of claim 14 , comprising a traffic shaper to selectively remove said video frames from said video bitstream in accordance with a set of received output parameters.

17. An article comprising a computer-readable medium excluding communications media containing instructions that if executed enable a system to receive a set of video information with a first number of video frames from a first client terminal in a conference call, the set of video information for a current speaker of the conference call, receive a video bit rate for said set of video information, receive a bandwidth estimate for a media communications channel with a second client terminal in said conference call, and calculate a second number of video frames to remove from said set of video information based on said video bit rate, said bandwidth estimate, a video frame type and a number of frames for said frame type.

18. The article of claim 17 , further comprising instructions that if executed enable the system to calculate said second number based on a defined structure for said set of video information, said defined structure including multiple video frame types and a frame ordering sequence.

19. The article of claim 17 , further comprising instructions that if executed enable the system to receive a set of input parameters comprising a description of a frame type composition used in a group of picture structure, said video bit rate for said set of video information, a number of bits used for each frame type for said first number of video frames, and a frame ordering sequence, and send a set of output parameters comprising a remove frame type, a number of remove frames for said remove frame type, and a location for each remove frame in said set of video information.

20. The article of claim 17 , further comprising instructions that if executed enable the system to remove said second number of video frames from said set of video information in accordance with a set of output parameters.