avcodec.h stopped including channel_layout.h per FFmpeg commit
1be3d8a0cb77 [1]. Fixes compilation error on macOS against
FFmpeg later than the mentioned commit.
[1] 1be3d8a0cb
avcodec.h stopped including channel_layout.h per FFmpeg commit
1be3d8a0cb77 [1]. Fixes compilation error on macOS against
FFmpeg later than the mentioned commit.
[1] 1be3d8a0cb