FFmpeg doesn't have a particularly stable API or ABI. Dynamically
linking to it isn't that great of an idea because the .so number version
increments fairly often requiring at least a relink. The audio decode
routine is up to avcodec_decode_audio4 by now, and who knows when
avcodec_decode_audio5 will happen. The deprecated functions do
eventually get removed and distros can have them compiled out.
It's a really good lib if you can require specific versions, and either
static-link it or ship with the version you build with, but I imagine
the constantly-breaking ABI would be more of a headache for a codebase
like Wine unless you directly copy over the code (but then, why not just
take the decoder routines ffmpeg has and wrap them into whatever Windows
audio decoder API?).
Another issue is that ffmpeg requires C99 to build, whereas Wine doesn't.
