Method for encoding of a video stream

1. A computer-implemented method for synchronizing a video conference between a set of participants, comprising:

receiving, from a terminal associated with a first participant, a first temporal sequence of frames of a first video stream, the first temporal sequence of frames including first non-prediction-encoded frames and first prediction-encoded frames;

receiving, from a terminal associated with a second participant, a second temporal sequence of frames of a second video stream, the second temporal sequence of frames including second non-prediction-encoded frames and second prediction-encoded frames;

deriving a synchronization signal using the first temporal sequence of frames or the second temporal sequence of frames; and

sending, to at least one of the terminal associated with the first participant or the terminal associated with the second participant, the synchronization signal for causing transmission of a first subsequent non-prediction-encoded frame of the first temporal sequence of frames and a second subsequent non-prediction-encoded frame of the second temporal sequence of frames.

2. The computer-implemented method of claim 1 , further comprising:

receiving the first subsequent non-prediction-encoded frame of the first temporal sequence of frames and the second subsequent non-prediction-encoded frame of the second temporal sequence of frames; and

mixing the first subsequent non-prediction-encoded frame of the first temporal sequence of frames and the second subsequent non-prediction-encoded frame of the second temporal sequence of frames to generate a mixed video stream.

3. The computer-implemented method of claim 1 , further comprising:

identifying a predictive structure for encoding the first video stream or the second video stream; and

wherein deriving the synchronization signal comprises deriving using the predictive structure.

4. The computer-implemented method of claim 1 , wherein sending the synchronization signal causes shortening of a first picture group length of the first video stream or a second picture group length of the second video stream.

5. The computer-implemented method of claim 1 , wherein sending the synchronization signal causes reducing a first number of pictures of the first video stream or a second number of pictures of the second video stream to generate a time offset.

6. The computer-implemented method of claim 1 , wherein sending the synchronization signal causes decreasing occurrences of multiple references in the first prediction-encoded frames or in the second prediction-encoded frames.

7. The computer-implemented method of claim 1 , wherein sending the synchronization signal causes video encoding to start at a first length of a first group of pictures of the first video stream or at a second length of a second group of pictures of the second video stream.

8. A non-transitory, computer-readable medium for synchronizing a video conference between a set of participants, the computer-readable medium storing instructions that, when executed by a processor, cause the processor to perform the steps of:

receiving, from a terminal associated with a first participant, a first temporal sequence of frames of a first video stream, the first temporal sequence of frames including first non-prediction-encoded frames and first prediction-encoded frames;

receiving, from a terminal associated with a second participant, a second temporal sequence of frames of a second video stream, the second temporal sequence of frames including second non-prediction-encoded frames and second prediction-encoded frames;

deriving a synchronization signal using the first temporal sequence of frames or the second temporal sequence of frames; and

sending, to at least one of the terminal associated with the first participant or the terminal associated with the second participant, the synchronization signal for causing transmission of a first subsequent non-prediction-encoded frame of the first temporal sequence of frames and a second subsequent non-prediction-encoded frame of the second temporal sequence of frames.

9. The non-transitory, computer-readable medium of claim 8 , storing further instructions that, when executed by the processor, cause:

receiving the first subsequent non-prediction-encoded frame of the first temporal sequence of frames and the second subsequent non-prediction-encoded frame of the second temporal sequence of frames; and

mixing the first subsequent non-prediction-encoded frame of the first temporal sequence of frames and the second non-prediction-encoded subsequent frame of the second temporal sequence of frames to generate a mixed video stream.

10. The non-transitory, computer-readable medium of claim 8 , storing further instructions that, when executed by the processor, cause:

identifying a predictive structure for encoding the first video stream or the second video stream; and

wherein deriving the synchronization signal comprises deriving using the predictive structure.

11. The non-transitory, computer-readable medium of claim 8 , wherein sending the synchronization signal causes shortening of a first picture group length of the first video stream or a second picture group length of the second video stream.

12. The non-transitory, computer-readable medium of claim 8 , wherein sending the synchronization signal causes reducing a first number of pictures of the first video stream or a second number of pictures of the second video stream to generate a time offset.

13. The non-transitory, computer-readable medium of claim 8 , wherein sending the synchronization signal causes video encoding to start at a first picture number of the first video stream or a second picture number of the second video stream.

14. The non-transitory, computer-readable medium of claim 8 , wherein sending the synchronization signal causes video encoding to start at a first length of a first group of pictures of the first video stream or at a second length of a second group of pictures of the second video stream.

15. A conferencing system, comprising:

a processor;

a memory operatively connected to the processor and storing instructions for synchronizing a video conference between a set of participants, when the instructions are executed by the processor, they cause the at least one processor to perform the steps of:

receiving, from a terminal associated with a first participant, a first temporal sequence of frames of a first video stream, the first temporal sequence of frames including first non-prediction-encoded frames and first prediction-encoded frames;

receiving, from a terminal associated with a second participant, a second temporal sequence of frames of a second video stream, the second temporal sequence of frames including second non-prediction-encoded frames and second prediction-encoded frames;

deriving a synchronization signal using the first temporal sequence of frames or the second temporal sequence of frames; and

sending, to at least one of the terminal associated with the first participant or the terminal associated with the second participant, the synchronization signal for causing transmission of a first subsequent non-prediction-encoded frame of the first temporal sequence of frames and a second subsequent non-prediction-encoded frame of the second temporal sequence of frames.

16. The conferencing system of claim 15 , wherein the memory stores further instructions that, when executed by the processor, cause:

receiving the first subsequent non-prediction-encoded frame of the first temporal sequence of frames and the second subsequent non-prediction-encoded frame of the second temporal sequence of frames; and

mixing the first subsequent non-prediction-encoded frame of the first temporal sequence of frames and the second subsequent non-prediction-encoded frame of the second temporal sequence of frames to generate a mixed video stream.

17. The conferencing system of claim 15 , wherein the memory stores further instructions that, when executed by the processor, cause:

identifying a predictive structure for encoding the first video stream or the second video stream; and

wherein deriving the synchronization signal comprises deriving using the predictive structure.

18. The conferencing system of claim 15 , wherein sending the synchronization signal causes shortening of a first picture group length of the first video stream or a second picture group length of the second video stream.

19. The conferencing system of claim 15 , wherein the synchronization signal causes a simultaneous transmission of the first subsequent non-prediction-encoded frame and the second subsequent non-prediction-encoded frame.

20. The conferencing system of claim 15 , wherein sending the synchronization signal causes video encoding to start at a first length of a first group of pictures of the first video stream or at a second length of a second group of pictures of the second video stream.