Perceptually-Based Joint-Program Audio Coding

Some digital audio broadcasting systems, such as Satellite Digital Audio Radio Services (SDARS), transmit many audio programs over the same transmission channel. Instead of splitting up the channel into fixed bitrate subchannels, each carrying one audio program, one can dynamically distribute the channel capacity among the audio programs. We describe an algorithm which implements this concept taking into account statistics of the bitrate variation of audio coders and perception. The result is a dynamic distribution of the channel capacity among the coders depending on the perceptual entropy of the individual programs. This solution provides improved audio quality compared with fixed bitrate subchannels for the same total transmission capacity. The proposed scheme is non-iterative and has a low computational complexity.