win-capture-audio
An OBS plugin based on OBS's win-capture/game-capture that hooks WASAPI's audio output functions (rather than the various graphics API funcitons) that enables capture of audio streams directly from applications. This eliminates the need for third-party software or hardware audio mixing tools that introduce complexity, and in the case of software tools introduce mandatory latency.
The modus operandi is identical to the aforementioned game-capture plugin (and most likely to Discord's solution), and is inherently liable to instability and other issues due to the lack of a more "official" solution from the Windows API.
WARNING: I am not able to guarantee that using this is anti-cheat safe, however similar hook methods are employed in many widely deployed applications (Discord, Steam Overlay, RTSS, NVIDIA's ShadowPlay, etc...).
Limitations (current)
- WASAPI only (no DirectSound, WaveOut, etc...)
- No Windows App support (probably?)
- Chrome and Chrome-based (e.g. Electron) applications don't work (probably a limitation of the process selection logic rather than the hooking)
- Directly conflicts with Discord streaming (and maybe ShadowPlay) (unresolvable?)
Installation and Usage
- Head over to the Releases page and download the latest installer (or zip if you are using a portable installation)
- Run the setup wizard, selecting your OBS folder when asked (or extract the zip to the portable OBS root directory)
- Lauch OBS and check out the newly available "Application Audio Output Capture" source