Commetrex’ 60094-2 speech coder is a resource- efficient implementation of the ITU G.723.1 on the Texas Instruments TMS32C6000 family of DSPs. G.723.1 is widely deployed in H.324 conferencing systems and PSTN-IP gateways where high-quality speech and low-bandwidth utilization are requirements.
G.723.1 specifies coding schemes that compress 64-KBPS PCM speech to either 5.3- or 6.3-KBPS. The lower-bit-rate coder uses “algebraic-code- excitation linear prediction” (ACELP) as the coding scheme; the higher-bit-rate coder uses “multi-pulse maximum-likelihood excitation” (MP-MLQ). Each coder is designed to process frames of 240 samples, or 30-milliseconds of speech data. It is possible to switch between the two rates on any 30-msec frame boundary.
The 60094-2 speech coder includes the silence compression specified in G.723.1 Annex A. Voice- activity detection (VAD) and comfort-noise generation are included.
60094-2 is eXpress DSP Compliant (http://dspvillage.ti.com/docs/express_dsp/expr essdsphome.jhtmll). The TMS320DSP Algorithm Standard is directly supported by the MSP Consortium M.100 specification (http://www.msp.org) so it is compatible with any MSP-conforming media-processing system.