RATE CONTROL ALGORITHM FOR SCALABLE VIDEO ENCODING WITH DISPOSABLE P-FRAMES

摘要

Systems and methods of performing rate control in scalable video encoders that can be used to provide videoconferencing, announcements, and live video streaming to multiple participant devices having diverse bandwidths, resolutions, and/or other device characteristics. The systems and methods can accommodate different target bit rates of the multiple participant devices by operating on scalable video bitstreams in a multi-layer video format, including a base layer having one or more reference video frames, and an enhancement layer having one or more disposable non-reference, predictive video frames. By adjusting the number of disposable non-reference, predictive video frames in the enhancement layer, as well as quantization parameters for the respective base and enhancement layers, the disclosed systems and methods can accommodate the different target bit rates for the respective participant devices, while enhancing the spatial and/or temporal qualities of the base and enhancement layers in the respective video bitstreams.

主权项

1. A method of performing rate control in a scalable video encoder, comprising:
generating a scalable video bitstream from a source video sequence that includes a plurality of video frames, the scalable video bitstream including a base layer and an enhancement layer, the base layer including a first number of the plurality of video frames encoded as reference video frames, the enhancement layer including a second number of the plurality of video frames encoded as non-reference, predictive video frames, the base layer and the enhancement layer each having an associated target bit rate; obtaining a target bit rate associated with at least one user device; adjusting the second number of the plurality of video frames encoded as non-reference, predictive video frames in the enhancement layer based at least on a current bit usage in the base layer, the target bit rate of the base layer, and the target bit rate of the enhancement layer, for subsequent transmission of the scalable video bitstream to the user device at the target bit rate of the user device; and adjusting a quantization parameter for the second number of the plurality of video frames encoded as non-reference, predictive video frames in the enhancement layer to increase accuracy of the rate control in the scalable video encoder.