subject: G.723.1 Vocoder For Video Phones, Audio/video Conferencing And Media Gateways [print this page] Toronto, Canada - GAO Research IncToronto, Canada - GAO Research Inc. (www.GAOResearch.com) has announced the release of its G.723.1 Vocoder which is ideal for applications such as video phones, audio/video conferencing and media gateways. This G.723.1 vocoder includes Silence Compression Scheme and Voice Activity Detection (VAD).
GAO's G.723.1 dual rate speech coder performs compression and decompression of 8 kHz speech signals with a compression ratio of up to 12:1. It encodes 16-bit PCM samples into 16-bit code-words yielding 10 or 12 code-words per 240 sample frames for 5.3 kbps and 6.3 kbps channels respectively. G.723.1 software has switchable transmission rates over 5.3 or 6.3 kbps channels providing 4 kHz of quality speech bandwidth in conformance with the ITU-T standard. The higher bit rate has greater quality; the lower bit rate gives good quality and provides system designers with additional flexibility.
The ITU-T G.723.1 standard specifies a coded representation that can be used for compressing the speech or other audio signal components of multimedia services at a very low bit rate as part of the overall H.324 family of standards. It encodes speech or other audio signals in frames using linear predictive analysis-by-synthesis coding. The excitation signal for the high rate coder is Multi-pulse Maximum Likelihood Quantization (MP-MLQ) and for the low rate coder is Algebraic-Code-Excited Linear-Prediction (ACELP).
This G.711 Vocoder Belongs to GAO's family of Speech Vocoders. This line of vocoders complies with the ITU-T Vocoder standards for speech processing software and audio processing codecs. This line also includes G.722 Vocoder which Complies with the ITU-T H.320 standard for video conferencing, G.711 vocoder which provides a compression /decompression (companding) algorithm to deliver precision transmissions of encoded speech signals sampled at the rate of 8 kHz and G.728 LD-CELP Vocoder which implements the low delay code-excited linear prediction (LD-CELP) speech compression technique specified in the ITU-T standard and provides approximately 4 kHz of speech bandwidth.
About GAO Research Inc.
GAO Research Inc. (www.GAOResearch.com) is a world-renowned provider of high quality, reliable telecommunications software including embedded modem software, fax modem software, speech codes, and telephony software for a wide range of DSPs and microprocessors.
Toronto, Canada - GAO Research Inc. (www.GAOResearch.com) has announced the release of its G.723.1 Vocoder which is ideal for applications such as video phones, audio/video conferencing and media gateways. This G.723.1 vocoder includes Silence Compression Scheme and Voice Activity Detection (VAD).
