Complete Communications Engineering

G.729 Annex D is a low bit-rate variant of the G.729 speech codec.  G.729 Annex D encodes a 10ms (80 sample) frame into 64 bits, while G.729 (and G.729 Annex A) encodes a frame into 80 bits.

itu g729 d G.729 Annex D

G.729 Annex D does have a lower bit rate than the main body G.729.  G.729 Annex D is able to achieve a lower bit rate by using a sparser ACELP codebook, further quantization on the codebook gains and pitch delay.  The tradeoff for this lower bit rate is lower result speech quality, but is still higher quality than many narrowband codecs, such as GSM-HR.  This allows a system integrator to select between G.729 or G.729 Annex D based on network conditions.

Configurations

VOCAL’s G.729 Annex D voice compression algorithm is optimized for performance on leading DSPs and RISC/CISC processors from TI, ADI, AMD, ARM, Intel and other vendors. VOCAL offers the G.729 codec as a standalone algorithm, as part of a modular software library suite, as well as with a VoIP stack. Contact us to discuss your G.729 vocoder application requirements.

Platforms

supported platforms

VOCAL’s G.729 Annex D voice compression algorithm is optimized for performance on leading DSPs and RISC/CISC processors from TI, ADI, AMD, ARM, Intel and other vendors. VOCAL offers the G.729 codec as a standalone algorithm, as part of a modular software library suite, as well as with a VoIP stack. Please contact us to discuss your G.729 vocoder application requirements.

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
  • VOCAL LANsEND
  • Google Android
  • Green Hills Integrity
  • Micrium μCOS
  • Symbian
  • Wind River VxWorks
  • eCOS / eCOSPro