Use Case | Channels | Bitrate (Kb/s) | Notes |
---|---|---|---|
Low bandwidth HF/VHF digital radio | 1 (mono) | Use Codec 2 | Opus only supports bitrates down to 6 Kb/s. Codec 2 handles ultra low bitrate speech at 0.7 - 3.2 Kb/s. |
VoIP | 1 | 10 - 24 | 10 Kb/s will deliver narrowband most of the time, 24 Kb/s should give fullband. More details in the relevant table further down this page. |
Audiobooks / Podcasts | 1 | 24 | Bitrates from here on up tend to deliver fullband audio. |
2 (stereo) | 32 | ||
Music Streaming / Radio | 2 | 64 - 96 | Opus has better quality than MP3, AAC and Vorbis at these rates. (listening test results: 64 Kb/s, 96 Kb/s) |
Music Storage | 2 | 96 - 128 | Opus at 128 KB/s (VBR) is pretty much transparent. |
6 (5.1 surround) | 128 - 256 | For surround sound, Opus uses surround-sound bitrate allocation. | |
8 (7.1 surround) | 256 - 450 | ||
Music Archiving | 1 - 8 | Use FLAC | If you are archiving audio, use a lossless audio format to prevent generation loss. |
--downmix-mono
- downmixes all input channels to mono--downmix-stereo
- downmixes all input channels to stereo (if there are more than 2 input channels, e.g. surround sound)Bandpass Range (Hz) | Rough Bitrate Required (Kb/s) | |||
---|---|---|---|---|
Mono | Stereo | |||
Voice | Music | Voice | Music | |
NarrowBand (3 - 4000) | 12 | 15 | ? | ? |
MediumBand (3 - 6000) | 15 | 18-22 | ? | ? |
WideBand (3 - 8000) | 16-20 | 22-28 | ? | ? |
SuperWideBand (3-12000) | 24-28 | 28-32 | ? | ? |
FullBand (3-20000) | 28-40 | 32-64 | 32-64 | 64-128 |