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something that always amazes me about OBS is how it is seamlessly cross-platform... and yet I assume the low-level ability to capture display output must be hig

something that always amazes me about OBS is how it is seamlessly cross-platform... and yet I assume the low-level ability to capture display output must be highly platform-dependent? Does OBS need to maintain totally distinct logic for capturing display output from different OSs? Or is there already an abstraction layer for this, maybe at the driver level? Or, third possibility - does it depend on a separate project/library for that? (I'm ready for the replies saying "read the source and find out" but I'm hoping for someone smarter than I to make sense of it for me :D)

xconverge 5y ago
Looks to be managed here https://github.com/obsproject/obs-studio/tree/master/plugins https://github.com/obsproject/obs-studio/tree/master/plugins Pretty clean source tree to reference :) Seems to be unique per OS and not dependent on third party projects.
- dodgepong 5y ago
  Indeed, all capture functionality is split out into plugins and they are platform-specific. Platform builds are handled by CMake to only include relevant plugins: https://github.com/obsproject/obs-studio/blob/master/plugins/CMakeLists.txt https://github.com/obsproject/obs-studio/blob/master/plugins...
qbasic_forever 5y ago
It looks like they have their own library for low level stuff (https://github.com/obsproject/obs-studio/tree/master/libobs https://github.com/obsproject/obs-studio/tree/master/libobs), but for the most part rely on ffmpeg's library for all the platform-specific video, audio, etc. stuff (https://www.ffmpeg.org/about.html https://www.ffmpeg.org/about.html). If you browse the CMakeLists.txt files in the repo you can get a rough idea the kinds of libraries they depend on and use.
- dodgepong 5y ago
  OBS uses FFmpeg for media source playback, some audio encoders, and specific video output contexts. Usually FFmpeg isn't used for video encoding, though -- that's handled by either a direct hardware encoder implementation or by a native x264 encoder (i.e. not FFmpeg's x264 implementation). OBS supports FFmpeg output in Advanced mode, but it's by no means the default.
HMH 5y ago
I have been following the development of screen capturing under Wayland a little and what I can tell you is that at least for Wayland OBS directly interfaces with pipewire (which is very much platform specific and low level), see: https://github.com/obsproject/obs-studio/pull/4287/files https://github.com/obsproject/obs-studio/pull/4287/files
ta988 5y ago
I had to install it to a colleague macos computer and it was a pain to setup the computer audio recording. Had to install a third-party closed source plugin, configure it...
- darkteflon 5y ago
  You can use [BlackHole](https://github.com/ExistentialAudio/BlackHole https://github.com/ExistentialAudio/BlackHole) for that, which is open-source, GPL-3. I do, it works, it’s great.
  - ta988 5y ago
    Thanks a lot!
stoicjumbotron 5y ago
Highly OT, but why did you use "smarter than I" instead of "smarter than me"? What is the difference between these two?

xconverge 5y ago

Looks to be managed here https://github.com/obsproject/obs-studio/tree/master/plugins https://github.com/obsproject/obs-studio/tree/master/plugins Pretty clean source tree to reference :) Seems to be unique per OS and not dependent on third party projects.

dodgepong 5y ago
Indeed, all capture functionality is split out into plugins and they are platform-specific. Platform builds are handled by CMake to only include relevant plugins: https://github.com/obsproject/obs-studio/blob/master/plugins/CMakeLists.txt https://github.com/obsproject/obs-studio/blob/master/plugins...

qbasic_forever 5y ago

It looks like they have their own library for low level stuff (https://github.com/obsproject/obs-studio/tree/master/libobs https://github.com/obsproject/obs-studio/tree/master/libobs), but for the most part rely on ffmpeg's library for all the platform-specific video, audio, etc. stuff (https://www.ffmpeg.org/about.html https://www.ffmpeg.org/about.html). If you browse the CMakeLists.txt files in the repo you can get a rough idea the kinds of libraries they depend on and use.

dodgepong 5y ago
OBS uses FFmpeg for media source playback, some audio encoders, and specific video output contexts. Usually FFmpeg isn't used for video encoding, though -- that's handled by either a direct hardware encoder implementation or by a native x264 encoder (i.e. not FFmpeg's x264 implementation). OBS supports FFmpeg output in Advanced mode, but it's by no means the default.

HMH 5y ago

I have been following the development of screen capturing under Wayland a little and what I can tell you is that at least for Wayland OBS directly interfaces with pipewire (which is very much platform specific and low level), see: https://github.com/obsproject/obs-studio/pull/4287/files https://github.com/obsproject/obs-studio/pull/4287/files

ta988 5y ago

I had to install it to a colleague macos computer and it was a pain to setup the computer audio recording. Had to install a third-party closed source plugin, configure it...

darkteflon 5y ago
You can use [BlackHole](https://github.com/ExistentialAudio/BlackHole https://github.com/ExistentialAudio/BlackHole) for that, which is open-source, GPL-3. I do, it works, it’s great.
- ta988 5y ago
  Thanks a lot!

stoicjumbotron 5y ago

Highly OT, but why did you use "smarter than I" instead of "smarter than me"? What is the difference between these two?