Rate-Distortion Optimization for Encoding Frame of Video Stream Using Feedback from Receiving Terminal

摘要

A rate-distortion optimization process comprises selecting an encoding mode (e.g. inter prediction mode) for each of a plurality of image portions to be encoded in each of a plurality of frames by optimizing a function comprising a distortion estimate for the portion and a measure of bit rate required to encode the portion. The distortion estimate is based on source coding distortion and an estimate of a distortion that would be experienced due to possible loss over the transmission channel. The image portion is encoded into the encoded video stream using the selected mode and the encoded video stream is transmitted over the channel. The rate-distortion optimization process for a current frame is performed in dependence on feedback received from the receiving terminal based on an earlier one of the frames. The feedback may include an indication that only part of the earlier frame was received.