Low latency high resolution video encoding
Video data that is associated with a videoconference or a telepresence session is captured and a video signal relating thereto is provided. The video signal is divided into segments, which are identical from one video frame to another subsequent video frame within the video signal. Each segment is encoded independently, to result in encoded segment data such that both I-frames and P-frames are generated for a given segment, so as to support independent reconstruction of segments at a distant end. The encoded segment data is transmitted subsequently to the distant end.
1. A method of encoding in real time a video signal that is associated with a videoconference or telepresence session, the method comprising:
capturing a stream of video data comprising a series of sequential video frames;
separating the video frames into a plurality of frame segments, wherein each frame segment represents a part of a complete video frame;
encoding each frame segment independently and in parallel to generate parallel encoded data streams, one for each of the plurality of frame segments, each encoded data stream containing a sequence of frame segment instances each corresponding to a particular frame segment in the video frames, and each encoded data stream containing I-frame segment instances that carry complete information about a particular frame segment and P-frame segment instances that carry partial information about the particular frame segment, the partial information representing information that has changed relative to a previous frame segment instance in that encoded data stream, and wherein the encoding of the frame segments for each frame is performed such that when an instance of one of the frame segments within a particular frame is an I-frame segment instance, at least one of the other frame segment instances in that particular frame is a P-frame segment instance, whereby in the respective parallel encoded data streams in any period of time when an I-frame segment instance is present in one of the parallel encoded data streams, a P-frame segment instance is present in at least one of the other parallel encoded data streams;
transmitting the parallel encoded data streams independently over a network to a receiver to permit the receiver to decode each frame segment and recombine the decoded frame segments from the different encoded data streams to reproduce an image;
wherein during transmission of I-frame segment instances of one of the frame segments, P-frame segment instances of all other frame segments are transmitted.
2. A method according to claim 1 , wherein the frame segments correspond to predetermined parts of the video frames.
3. A method according to claim 1 , wherein each frame segment corresponds to a different predetermined area of the video frames.
4. A method according to claim 1 , wherein the frame segments are uniformly sized geometric shapes.
5. A method according to claim 1 , wherein at least one of frame segment size and shape is different for one of the frame segments compared to another of the frame segments.
6. A method according to claim 1 , wherein at least one of the frame segments comprises a plurality of predetermined non-contiguous areas of the video frames.
7. A method according to claim 1 , wherein the frame segments are determined in dependence upon external application data and indicative of the amount of motion that is expected in different areas of the video frames.
8. A method according to claim 1 , wherein the frame segments are determined in dependence upon external prior use data indicative of the amount of motion previously determined in different areas of the video frames.
9. A method according to claim 1 , wherein a period between regularly spaced I-frame segment instances for one of the frame segments is different than a period between regularly spaced I-frame segment instances for another of the frame segments.
10. A method according to claim 1 , wherein the frame segments are encoded in encoders having different encoding characteristics.
11. A method according to claim 10 , wherein at least one of the encoders has a bitrate that is greater than a bitrate of the other encoders.
12. A video encoding system for encoding in real time a video signal that is associated with one of a videoconference and a telepresence session, the system comprising:
a port for receiving a stream of video data comprising a series of sequential video frames;
a divider for dividing the stream of video data into a series of substreams of data corresponding to frame segments, wherein each frame segment represents a part of a complete video frame;
a plurality of video encoders arranged in parallel for independently encoding the respective frame segments to generate parallel encoded data streams, one for each of the plurality of frame segments, each encoded data stream containing I-frame segment instances that carry complete information about a particular frame segment and P-frame segment instances that carry partial information about a particular frame segment, the partial information representing information that has changed relative to a previous frame segment instance in that encoded data stream, and the video encoders being arranged to encode each frame segment such that when an instance of one of the frame segments within a particular frame is an I-frame segment instance, at least one of the other frame segment instances in that particular frame is a P-frame segment instance, whereby in the respective parallel encoded data streams in any period of time when an I-frame segment instance is present in one of the parallel encoded data streams, a P-frame segment instance is present in at least one of the other parallel encoded data streams; and
a transceiver for transmitting the parallel encoded data streams independently over a network to a receiver to permit the receiver to decode each frame segment and recombine the decoded frame segments to reproduce an image;
wherein during transmission of I-frame segment instances of one of the frame segments, P-frame segment instances of all other frame segments are transmitted.
13. A video encoding system according to claim 12 comprising: a memory for storing predetermined data defining the frame segments, which correspond to predetermined parts of the video frames.