Research Article Open Access

Bitrate Scalability for Multi-Pulse Based Code Excited Linear Prediction Speech Coder

Suphattharachai Chomphan1 and Chutarat Chompunth1
  • 1 ,
American Journal of Applied Sciences
Volume 9 No. 3, 2012, 309-312

DOI: https://doi.org/10.3844/ajassp.2012.309.312

Published On: 14 January 2012

How to Cite: Chomphan, S. & Chompunth, C. (2012). Bitrate Scalability for Multi-Pulse Based Code Excited Linear Prediction Speech Coder. American Journal of Applied Sciences, 9(3), 309-312. https://doi.org/10.3844/ajassp.2012.309.312

Abstract

Problem statement: The bitrate scalability is an important functionality that is defined in the Moving Picture Expert Group (MPEG-4) requirements. Since the traffic in a communication network varies with time, the capability of varying the bitrate of a speech coder is needed. Approach: This study proposes an approach to vary the bitrate by using a bitrate scalable tool which is attached with the core section of Multi-Pulse based Code Excited Linear Predictive (MP-CELP) coder. The bitrates 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. Results: The experimental results show that the speech quality of the proposed coder with the bitrate scalable tools is improved above the speech quality of the conventional coder. Conclusion: From the study, the proposed approach gives a tool to improve the speech compression and can also support a variety of coder bitrates.

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Keywords

  • Thai speech
  • Multi-Pulse based Code Excited Linear Predictive (MP-CELP)
  • speech compression
  • bitrates scalability
  • MOS scores