Implementation of an enhanced fixed point Variable Bit-Rate MELP vocoder on TMS320C549

Ertan A., Aksu E., Ilk H., Karci H., Karpat O., Kolcak T., ...More

IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP 99), Arizona, United States Of America, 15 - 19 March 1999, pp.2295-2298 identifier

  • Publication Type: Conference Paper / Full Text
  • Doi Number: 10.1109/icassp.1999.758396
  • City: Arizona
  • Country: United States Of America
  • Page Numbers: pp.2295-2298
  • Middle East Technical University Affiliated: Yes


In this paper, a fixed point Variable Bit-Rate (VBR) Mixed Excitation Linear Predictive Coding (MELP(TM)) vocoder is presented. The VBR-MELP vocoder is also implemented on a TMS320C54x and it achieves virtually indistinguishable federal standard MELP quality at bit-rates between 1.0 to 1.6 kb/s. The backbone of VBR-MELP vocoder is similar to that of federal standard MELP. It utilizes a novel sub-band based voice activity detector in the back-end of encoder to discriminate background noise from speech activity. Since proposed detector uses only parameters extracted in the encoder, its computational complexity is very low.