Global optimization of multiplexed video encoders

Abstract

An algorithm is presented for increasing the overall video quality of multiple variable rate video encoders multiplexed onto a single constant bit-rate channel. This enables an encoder, that is processing complex video, to use more of the channel bandwidth than an encoder that is compressing less complex video. The encoder rates are continually adapted. A rate controller determines the channel rate for each encoder as well as the target rate allocated to individual pictures encoded by the encoders. The target rates for individual pictures are computed in order to maintain constant quality across encoders while the encoder channel rates are derived so as to avoid encoder and decoder buffer underflow and overflow.