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G.711 Vocoder Features A-law and µ-Law Encoding and Decoding

Toronto, Canada – GAO Research Inc. (www.GAOResearch.com) is offering its 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. The most common applications for GAO's G.711 Vocoder are data compression over telephone networks.

GAO's G.711 implementation includes independent user-callable functions that perform all of the μ-law and A-law encoding and decoding operations. The G.711 standard uses pulse code modulation (PCM) to compress, decompress, encode, and decode analog speech, which can then be transmitted and received as binary data.

The G.711 encoder creates a 64 kbps bit stream. It is compliant with the ITU-T G.711 standard which is a standard to represent 8 bit compressed pulse code modulation (PCM) samples for signals of voice frequencies sampled at the rate of 8000 samples/second. This standard has two forms: A-Law and µ-Law. The A-Law G.711 PCM encoder converts 13 bit linear PCM samples into 8 bit compressed PCM (logarithmic form) samples, and the decoder reverses the process. The µ-Law G.711 PCM encoder converts 14 bit linear PCM samples into 8 bit compressed PCM samples.

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.723.1 Vocoder which encodes 16-bit PCM samples into 16-bit code-words yielding 10 or 12 code-words per 240 sample frames for the 5.3 Kbps and 6.3 Kbps channels respectively 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.