&audiocodec
Lets you specify the audio codec
Viewer-Side Option! (&view, &scene, &room, &solo)
Options
Example: &audiocodec=opus
Details
&audiocodec on the viewer side can let you specify the audio codec; opus (default), pcmu, pcma, isac, g722, red and pcm.
red
&audiocodec=red is pretty much like sending two opus streams, with one as a backup in case of packet loss; support in Chromium 97 and up, but the only way I can so far tell that it is working is to check if the audio bitrate has doubled.
When using &proaudio, &stereo, or higher than &audiobitrate=216 with this, the resulting bitrate may not actually double. I don't quite understand what's going on here, if its still working or not, so to be safe when using &proaudio or &stereo, along with &audiocodec=red, I set the bitrate to 216 by default, which will then result in a sending bitrate of around 440-kbps.
I've tried to enable RED-mode to work with PCM audio, but so far it will only work with OPUS audio.
pcm
&audiocodec=pcm now will support 48khz and 44.1khz mono playback (48khz default), and if &stereo is used, it changes to two-channel stereo 32khz.
The existing &samplerate=44100 option can lower the sample rate of this pcm mode (down to 8khz even), and hence the resulting audio bitrate. Since PCM is raw, &audiobitrate won't work, so expect 550 to 1200-kbps in just audio bitrates per viewer.
There may be clicking when using PCM mode (L16) if you are on a bad connection, as PCM doesn't have much in the way of error correction. You'll need to address this yourself probably with post-processing if any issue.
Future options
In the near future you'll be able to send PCM audio via &chunked mode, which will guarantees delivery of all packets sent, however there may be buffering issues if your connection can't keep up with bandwidth requirements.
Currently &chunked mode does work with OPUS-audio though; please provide feedback and requests if you use it. Chunked mode does not support WHIP/WHEP or Meshcast.
Related
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