G.723.1A Dual Rate Speech Coder

The G.723.1A Dual Rate Speech Coder provides a coded representation used for compressing speech in either of two very low bit rates. The higher 6.3Kbits/s rate produces better reproduction, while the lower 5.3Kbits/s rate provides additional flexibility. It is possible to switch between the rates on any 30ms frame boundary.

Annex A of this Recommendation (G.723.1A) provides an optional silence compression system to reduce the transmitted bit rate during silent intervals of speech.

This coder was optimized to represent speech with a high quality of the two rates using a limited amount of complexity. Music and other audio signals are not represented a faithfully as speech, but can be compressed and decompressed using this coder.

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