On the Efficiency Difference Between Range and Huffman Coding on CELT Layer of Opus Audio Coder

This paper compares the coding efficiency between the range coder in the Opus coder and the Huffman coder used in the MP-3 (MPEG-I Layer 3) and MPEG-2 AAC. The results show that the range coder has efficiency advantage of about 9 % at a rate of 128 kbps. The simulation, in a sense, indicates that transcoding from the Opus format to MP-3 or AAC format will lead to quality degradation.