Adding 7.1 multichannel audio record and stream
Created by: pkviet
This is a very hasty proof-of-concept attempt to enable multichannel audio support for both recording and streaming with OBS 19.0.2.
- Downmixing of decklink is bypassed
- 7.1 channel selection is enabled in UI (settings > audio )
- max audio channels increased from 2 to 8 in audio-io.h
- flv-mux enabled with 7.1 audio (beware, rtmp supports multichannel but flv files do not)
This basically works :
- recording of 7.1 works fine in either standard or advanced recording mode with ts or mkv file
- streaming of mpeg-ts and rtmp with multichannel audio both work ==> this was checked by recording with ffmpeg the rtmp and mpeg-ts streams as mp4 and ts files respectively. (NB: mpeg-ts tcp stream works perfectly, but mpeg-ts udp has audio sync issues)
To do:
- improve code with a downmixing switch; downmixing should be a default option
- add other multichannel setups in the audio UI: 3.0 3.1 4.0 4.1 5.1 6.1 7.0 8.0 16.0 (8.0 and 16.0 have to be supported by the audio encoder ==> pcm is ok in mkv ; for aac 7.1 is probably max)