G.729 codec
G.729 codec
G.729 is a codec with low bandwidth requirements; it provides good audio quality.
- The codec encodes audio in frames of 10 ms long. Given a sampling frequency of 8 kHz, a 10 ms frame contains 80 audio samples.
- The codec algorithm encodes each frame into 10 bytes, so the resulting bitrate is 8 kbit/s in one direction.
- G.729 is a licensed codec. End-users who want to use this codec should buy a hardware that implements it (be it a VoIP phone or gateway).
- A frequently used variant of G.729 is G.729a. It is wire-compatible with the original codec but has lower CPU requirements.
| Codec & Bit Rate (Kbps) | Codec Sample Size (Bytes) | Codec Sample Interval (ms) | Mean Opinion Score (MOS) | Voice Payload Size (Bytes) | Voice Payload Size (ms) | Packets Per Second (PPS) | Bandwidth MP or FRF.12 (Kbps) | Bandwidth w/cRTP MP or FRF.12 (Kbps) | Bandwidth Ethernet (Kbps) |
|---|---|---|---|---|---|---|---|---|---|
| G.711 (64 Kbps) | 80 Bytes | 10 ms | 4.1 | 160 Bytes | 20 ms | 50 | 82.8 Kbps | 67.6 Kbps | 87.2 Kbps |
| G.729 (8 Kbps) | 10 Bytes | 10 ms | 3.92 | 20 Bytes | 20 ms | 50 | 26.8 Kbps | 11.6 Kbps | 31.2 Kbps |