ADT公司G729 方案指标

ADT公司G729 方案指标

G.729 Voice Compression Algorithm and its many annexes

G.729 is used in wireless voice, voice-over-packet-networks, multimedia, and voice circuit multiplexing applications.

FEATURES

Functions are C-callable.
Multi-channel capable.
The encoder and decoder meet all ITU G.729 compliance and interoperability requirements.
Can be integrated with echo cancellers.
Capable of in-band synchronization.
Available as part of Adaptive Digital’s G.PAK turnkey DSP software packages

Platform	G.729	G.729 A	G.729 B	G.729 AB	G.729 D	G.729 F	G.729 I & E
TI TMS320C64x+ / C66x	Available	Available	Available	Available	Available	Available
TI TMS320C67/674x	Available	Available	Available	Available	Available	Available	Available
TI TMS320C64x	Available	Available	Available	Available	Available	Available
TI TMS320C62x				Available
TI TMS320C55x	Available	Available	Available	Available	Available
TI TMS320C54x	Available	Available	Available	Available	Available
ARM9E				Available
ARM11				Available
ARM Cortex A8		Available		Available
ARM Cortex A9		Available		Available
ARM Cortex A15		Available		Available
ARM Cortex M3		Available		Available
ARM Cortex M4		Available		Available
Win32 Static**				Available	Available
Win32 DLL**		Available		Available	Available

** Windows 32 DLL - Contact Sales for specifications.

DESCRIPTION

The Adaptive Digital Technologies' G.729 voice coder software is an implementation of ITU Recommendation G.729 8 kbit/s CS-ACELP Speech Codec.

G.729 is an umbrella of vocoder standards. The G.729 vocoders perform voice compression at bit rates that vary between 6.4 and 12.4 kbps. The figure below shows an example of the G.729 vocoder connected to a digital communication channel. The input speech is fed into the G.729 encoder as a stream of16-bit PCM samples, sampled at a rate of 8000 samples/second. The G.729 encoder compresses the data into the Encode Stream. The encoder also outputs the DTX status, which is discussed later in this data sheet. The digital channel carries the data stream and DTX status to the decoder, which regenerates a representation of the original speech, and outputs it as the output speech – again as 16-bit PCM at a sampling rate of 8000 samples/second. Since G.729 is a uses lossy compression, the output speech is not identical to the input speech.

The decoder is also fed a frame erase flag, which is an indication that the decode stream has temporarily been corrupted. The decoder is able to “smooth over” the output , doing its best to conceal the loss of data and minimize the loss in voice quality. This process is known as packet loss concealment (PLC). It works surprisingly well even under high packet loss rates.

Adaptive Digital's G.729AB voice compression algorithm is a highly optimized version of the G.729 ITU Annex A and Annex B standard. G.729 AB offers toll quality speech at a reasonably low bit rate of 8Kbps. The G.729 AB codec uses Discontinuous Transmission (DTX), Voice Activity Detection (VAD), and Comfort Noise Generation (CNG) to reduce bandwidth usage. G.729AB is used in wireless voice, voice-over-packet-networks, multimedia, and voice circuit multiplexing applications.

Data sheet .pdf

Click here for G.729 information on the following topics. G.729 comparisons and differences.

✓ DECIPHERING THE MANY ANNEXES & APPENDICES of G.729

✓ PATENT ISSUES

✓ COMPARISON SHOPPING

SPECIFICATIONS

TI TMS320C6000

G.729 C64x, C64x+ / C66x