Accurate bit allocation and rate control for DCT domain video transcoding

For video transmission over heterogeneous networks and devices, the compressed video stream has to be converted into a lower transmission bit rate or a small spatial resolution. The operation of converting a video in compressed format into another video also in compressed format is called video transcoding. The specific transcoding issue mentioned here is referred to as bit rate adaptation or rate shaping. We present a novel bit allocation and rate control algorithm for DCT domain video transcoding. Implementation results show that the proposed algorithm can provide accurate bit allocation and better video quality. Compared to TMN-8, the proposed scheme can generate a more stable video stream and maintain an even buffer occupancy level. This rate control scheme can be used to provide flexible video bit rate adaptation and stable transmission of video streams over heterogeneous networks.