ITU G.711.0 Software

VOCAL offers the G.711.0 codec software as a standalone algorithm, as part of a modular software library suite, as well as with a VoIP stack.


ITU G.711.0 Lossless Codec is a variable bit rate codec which further compresses the G.711 A-law or mu-law symbols. G.711.0 can encode a frame of 40, 80, 160, 240 or 320 samples, and is configurable from frame to frame. The compression rate of the codec is dependent on the input characteristics of that frame’s signal, and is most effective on zero-mean speech and audio signals. The compression of a frame is independent of any previous frame. Thus, the only algorithm latency is a result of the buffering of the frame sample data.

G.711.0 codec employs multiple potential coding schemes. The coding method used for a given frame is selected by analysis of the input data and evaluation of multiple coding schemes. If the input frame values are between -2 and 1 or is constant, then a simple coding method will be selected. Otherwise, multiple coding methods will be tested to determine which produces the best result. A prefix code is placed as a header on the encoded data. That code will inform the decoder on which encoding scheme was used.

g.711.0 block diagram


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supported platforms

VOCAL’s optimized vocoder software is available for the following platforms. Please contact us for specific vocoder supported platforms.

ProcessorsOperating Systems
  • Texas Instruments – C6xx (TMS320C62x, TMS320C64x, TMS320C645x, TMS320C66x, TMS320C67x), DaVinci, OMAP, C5xx (TMS320C54x, TMS320C55x)
  • Analog Devices – Blackfin, ADSP-21xx, TigerSHARC, SHARC
  • PowerPC, PowerQUICC
  • MIPS – MIPS32, MIPS64, MIPS4Kc
  • ARM – ARM7, ARM9, ARM9E, ARM10E, ARM11, StrongARM, ARMCortex-A8/A9/A15/A3x/A5x/A7x, Cortex-M3/M4/M7/M33
  • Intel / AMD – x86, x64 (both 32 and 64 bit modes)
  • Linux, uClinux, BSD, Unix
  • Microsoft Windows ACM / RTC / CE / Mobile
  • Apple iOS / iPhone / iPad & MacOS
  • Google Android
  • Green Hills Integrity
  • Micrium μCOS
  • Symbian
  • Wind River VxWorks
  • eCOS / eCOSPro