VOCAL offers the G.729A vocoder as a standalone algorithm, as part of a modular software library suite, as well as with a VoIP stack for different integration options with developer applications. The G.729A codec software is optimized for performance on leading DSPs and RISC, CISC processors. Our speech compression software may be licensed as binary or source code with custom designs available to meet developer specific requirements. Contact us to discuss your voice application requirements.
- Compliant with G.729, Annex A, Annex B specifications
- Full and half duplex modes of operation
- Passes ITU test vectors
- Optimized for high performance on leading edge DSP architectures
- Multichannel implementation
- Multi-tasking environment compatible
The G.729A vocoder is a reduced complexity Conjugate-Structure Algebraic-Code-Excited Linear Prediction (CS-ACELP) speech compression algorithm defined in ITU-T G.729 Annex A. G.729A is interoperable with the G.729 codec. The reduction in complexity may result in a small decrease in voice quality. G.729A is suitable for VoIP or similar applications using multimedia, voice, and/or data although the G.729AB codec may be better in reducing bandwidth usage.
G.729A requires 10 ms input frames and generates frames of 80 bits in length. Since G.729A is based on the Code-Excited Linear Prediction (CELP) model, each 80 bit frame produced contains linear prediction coefficients, excitation code book indices, and gain parameters that are used by the decoder in order to reproduce speech. The inputs/outputs of G.729A are 16 bit linear PCM samples that are converted from/to an 8 kbps compressed data stream. G.729A has the same total algorithmic delay of 15 ms as the G.729 speech coder.
The majority of the changes made to reduce complexity were in the G.729A encoding. The perceptual weighting filter uses instead the Linear Prediction Filter Co-efficients, making computation of the weighted synthesis filtering much easier. Decimation is used in the open-loop pitch analysis to compute correlations with weighted speech. Searches of both the adaptive and fixed algebraic codebooks were simplified as well. In the G.729A decoder, some modifications were made in the adaptive postfilter.
- DAA interface using linear codec at 8.0 kHz sample rate
- Direct interface to 8.0 kHz PCM data stream (A-law or μ-law)
- North American/International Telephony (including caller ID) support available
- Simultaneous DTMF detector operation available – (less than 150 hits on Bellcore test tape typical)
- MF tone detectors, general purpose programmable tone detectors/generators available
- Data/Facsimile/Voice Distinction available
- Common compressed speech frame stream interface to support systems with multiple speech coders
- Dynamic speech coders selection if multiple speech codecs available
- Can be integrated with G.168 Echo Canceller and Tone Detection/Regeneration modules
- Multiple ports can be executed on a single DSP
- Can be integrated with VoIP stack
VOCAL’s G.729A vocoder software is available for the following Platforms:
- Texas Instruments - C6000 (TMS320C62x, TMS320C64x, TMS320C645x, TMS320C67x, DaVinci), OMAP, C5000 (TMS320C54x, TMS320C55x)
- Analog Devices – Blackfin, ADSP-21xx, TigerSHARC, SHARC
- AMCC – PowerPC
- MIPS – MIPS32, MIPS64, MIPS4Kc
- ARM – ARM7, ARM9, ARM9E, ARM10E, ARM11, StrongARM, ARM Cortex-A8, Cortex-M1
- iPhone / iPad
- CEVA – Teak, TeakLite, Palm, Oak
- Microchip dsPIC
- AMD x86 (MMX) – AMD Geode SC1200
- PowerQUICC – PowerQUICC Pro (83xx), PowerQUICC III (85xx) families
- Ikanos – Fusiv processors
- ARC Processor IP
- NXP Philips Trimedia – TM1000, TM1100, TM1300
- VeriSilicon (LSI Logic) ZSP
Please contact us for other supported platforms.
VOCAL’s speech coder software is available for the following Operating Systems:
- Unix, Linux, uClinux
- Microsoft Windows ACM / RTC / CE / Mobile
- Mac OS
- Green Hills Software
Please contact us for specific G.729A vocoder supported Operating Systems.