ITU-T G.729 Annex A Speech Coder for the TMS320C54x Generation |
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The ITU-T G.729 Annex A fixed-rate speech coder provides toll quality at very low bandwidth. G.729 compresses narrowband linear speech signals at a sample rate of 8kHz to 8kbps, using Conjugate-Structure, Algebraic Code-Excited Linear Prediction (CS-ACELP). The encoder extracts the parameters of the CELP coding model from 10-msec frames. G.729 Annex A is a less mathematically complex version of G.729. It requires roughly one half the cycles of G.729, yet is interoperable with it, with barely any loss of fidelity.
G.729 Annex A encoder is widely used in applications that require robust quality, including videoconferencing, internet, multimedia communications, satellite communications, and store/forward.
The G.729 Annex A is part of the DSP Wizard G.729 suite for TMS320C54x, which is comprised of five separate products:
| Algorithm | Complexity | SID Frames | Bit-rate |
|---|---|---|---|
| G.729 | High | No | 8.0kbps |
| G.729 Annex A | Low | No | 8.0kbps |
| G.729 Annex B | High | Yes | 8.0kbps |
| G.729 Annex A Annex B | Low | Yes | 8.0kbps |
| G.729 Annex D | Medium | No | 6.4kbps |
DSP Wizard’s G.729 Annex A implementation was designed for low resource requirements without sacrificing quality. It executes at 9.5 mips for worst-case data. The speed is faster than any other G.729 Annex A c54x implementation available. While it may seem that many dsp software vendors claim to have the best speeds, we can back up our claim. Please compare us to the competition.
| G.729 Annex A | Encoder | Decoder | Full Duplex |
|---|---|---|---|
| Program Code Memory (Kbytes) | 11.2 | 4.6 | 13.1 |
| Program Table Memory (Kbytes) | 0.0 | 0.0 | 0.0 |
| Data Table Memory (Kbytes) | 5.0 | 4.2 | 5.1 |
| Per Channel Data Memory (Kbytes) | 1.1 | 0.8 | 1.9 |
| Stack Memory (Kbytes) | 0.3 | 0.3 | 0.3 |
| Interrupt Latency (cycles) | 240 | 233 | 240 |
| Call Period (ms) | 10 | 10 | 10 |
| Processor Load: Worst-Case (MHz) | 7.9 | 1.6 | 9.5 |