MPEG audio bit rate scaling on coded data domain

摘要: Formerly, once the audio data is compressed, transcoding used to scale bit rate, where decoding and re-encoding are taking place. Therefore, manipulation of coded has been very complex time consuming work. We describe three algorithms for rate scaling in MPEG domain. One a bandwidth limitation method cutting higher frequency components until target satisfied. The other two use re-quantization process quantization step each subband modified. them reflects psychoacoustic model from allocation information obtained bitstream order improve efficiency. simulation results show that provides high conversion efficiency nearly equal sound quality can be as directly coding PCM by reflecting model. It also shown fast (factor six) have achieved when compared with method.