HPDR Technique for Tonal Language Speech Compression based on MP-CELP Coder with Multiple Bitrates and Bitrate Scalabilities

摘要

This paper proposes a modification of flexible Multi-Pulse based Code Excited Linear Predictive (MP-CELP) coder with multiple bitrates and bitrate scalabilities for tonal language speech in the multimedia applications. The coder consists of a core coder and bitrate scalable tools. The high pitch delay resolutions (HPDR) are applied to the adaptive codebook of" core coder for tonal language speech quality improvement. The bitrate scalable tool employs multi-stage excitation coding based on an embedded-coding approach. The multi-pulse excitation codebook at each stage is adaptively produced depending on the selected excitation signal at the previous stage. The experimental results show that the speech quality of the proposed coder is improved above the speech quality of the conventional coder without pitch-resolution adaptation.