Bridge Any Format
Transcoding convertește audio între codec-uri diferite, permițând voice AI să comunice cu orice endpoint.
Common Transcoding Scenarios
PSTN ↔ Voice AI
📞
G.711🤖
PCM 16kHzPSTN calls use G.711, STT needs 16kHz PCM. Transcode at media server.
WebRTC ↔ PSTN
🌐
Opus📞
G.711WebRTC uses Opus, PSTN requires G.711. Gateway transcodes both directions.
Transcoding Matrix
| From → To | G.711 | Opus | G.729 | PCM |
|---|---|---|---|---|
| G.711 | — | Easy | Lossy | Easy |
| Opus | Easy | — | Lossy | Easy |
| G.729 | Quality loss | Quality loss | — | Quality loss |
| PCM | Lossless | Excellent | Good | — |
Transcoding Impact
⚠️ Latency
Each transcode adds 5-20ms delay.
No transcode: ~0ms
1x transcode: +10ms
2x transcode: +20ms
⚠️ Quality
Lossy→Lossy conversion degrades quality.
G.711→Opus: Minimal loss
G.729→G.711: ~0.3 MOS drop
2x lossy: ~0.5 MOS drop
⚠️ CPU
Transcoding consumes CPU resources.
G.711↔PCM: Low
G.711↔Opus: Medium
G.729↔any: High
Best Practices
✓ Do
- • Negotiate matching codecs when possible
- • Use PCM as intermediate format
- • Transcode once, not multiple times
- • Monitor transcode queue depth
✗ Avoid
- • G.729↔G.729 through different codec
- • Multiple chained transcodes
- • Transcoding for same codec family
- • Running out of CPU headroom
Transcoding Stats
45%
Calls Transcoded
8ms
Avg Transcode Time
12%
CPU for Transcode
0.1
Avg MOS Impact