Add `libplacebo` as a supported (optional) library about homebrew-ffmpeg

[retokromer]

Done in #160

[slhck]

Good suggestion!

I think we still have to wait until ffmpeg 6.0 is out on Homebrew core, because libplacebo there still depends on ffmpeg 5.x. This is the open PR: Homebrew/homebrew-core#124363

[ahobsonsayers]

Interestingly, I was looking at the formula for libplacebo today and I'm actually unsure why ffmpeg is a dependency. Certainly it is not according to the libplacebo readme. I also tried modifying and installing the formula without ffmpeg as a dependency and libplacebo seems to work fine.

I was actually considering opening a PR over there, cos I can only deduct it was included as a dependency by mistake.

[slhck]

Yeah, you're right — thinking about it, it should be the other way around.

[retokromer]

Thank you @ahobsonsayers for the suggestion! Unless you open a PR before, possibly I can do it on Friday.

I was actually considering opening a PR over there, cos I can only deduct it was included as a dependency by mistake.

Update: I mean here on this repository. I have noticed your other PR.
Update 2: done.

[retokromer]

@ahobsonsayers : I have prepared a PR which should implement your suggestion, but I suggest to wait until your PR on Homebrew is done.

[ahobsonsayers]

@retokromer this is awesome! Thanks! You got on that amazingly quickly ☺️

[ahobsonsayers]

So I have created a PR to try and fix the libplacebo homebrew formula, however I am having problems getting it to work. If I'm honest I am a bit out of my depth as my background is not c++ and I have no experience in its toolchain or homebrews ecosystem for that matter.

Don't suppose anyone has any advice?

[slhck]

I'm afraid this is also beyond my experience!

[bbgdzxng1]

@ahobsonsayers, recent work on libplacebo in Homebrew/homebrew-core#153961 may help - there have been a few changes to libplacebo regarding shaderc/glslang and removing sdl2 as a dependency for plplay. Furthermore, it may be worth revisiting now that FFmpeg 6.1 is out. I'm too stupid to fully understand the implications, but it looks like there has been some housekeeping which may now clear upstream dependencies. Please ignore (or thumbs down) if this comment is irrelevant. Thanks for everyone's efforts in trying to get libplacebo into the homebrew-ffmpeg tap.

[ahobsonsayers]

@bbgdzxng1 thanks for the ping. I had been following the progress of that PR but hadn't noticed it had been merged. I'll see if I can have another look at it this weekend and hopefully create a PR to get it all working!