[feature] Support CMake build system.

[Haowei Hsu]

Since CMake is the most popular build system of C/C++, I would expect that FFmpeg can support using CMake to compile the source code. Moreover, I hope that CMake can provide Config files for find_package() and Imported Targets.

Normally, there would be the following files generated for find_package() in Config Mode:

• ffmpeg-config.cmake
• ffmpeg-config-version.cmake
• ffmpeg-targets.cmake
• ffmpeg-targets-[debug|release].cmake

As for Imported Targets, consider FFmpeg has several components, I suggest that it take Qt or Poco for reference, providing the following Component Imported Targets with the namespace ffmpeg:::

• ffmpeg::avcodec
• ffmpeg::avformat
• ffmpeg::avfilter
• ffmpeg::avdevice
• ffmpeg::avutil
• ffmpeg::swscale
• ffmpeg::swresample
• ffmpeg::postproc

[Haowei Hsu]

Replying to Elon Musk:

Why not support using CMake to build the FFmpeg project? Does it have some obstacles?

It seems that CMake is more convenient to compile the Cross-Platform projects.

If there are some obstacles indeed, then I suggest to provide some CMake-specific Config Files for find_package() at least.

[Balling]

Cmake is extra dependency. Why does linux kernel not do it? Same here.

It does not matter anyway, ffmpeg really requires a big framework to comfortably check everything out and compile all together.

[Haowei Hsu]

Replying to Balling:

Cmake is extra dependency. Why does linux kernel not do it? Same here.

It does not matter anyway, ffmpeg really requires a big framework to comfortably check everything out and compile all together.

What does it matter with "linux kernel"? What do you mean "big framework"?

I was thinking that since lots of C/C++ libraries use CMake as their build system, it is better for FFmpeg to do so, as well. Besides, using CMake to build projects is more convienient and easy-to-use in Windows.

[Elon Musk]

Sorry, bunch of FFmpeg devs are not switching to cmake anytime soon.
Besides there are more important task to be done first.

[Balling]

linux kernel (mainline, that is, no one uses it, everyone uses backports repo) ​https://github.com/torvalds/linux

big framework: ​https://github.com/rdp/ffmpeg-windows-build-helpers and many others.

[S.Nijboer]

If it's more about not willing to put in the effort of porting over, I'm more than willing to do so.