mac编译ffmpeg

- code：

git clone https://git.ffmpeg.org/gitweb/ffmpeg.git

- 编译安装

https://trac.ffmpeg.org/wiki/CompilationGuide

        - 使用homebrew安装dependency

brew install automake fdk-aac git lame libass libtool libvorbis libvpx \
opus sdl shtool texi2html theora wget x264 x265 xvid nasm openssl rtmpdump

其中，                

• ​x264 encodes H.264 video. Use --enable-gpl --enable-libx264.
• ​fdk-aac encodes AAC audio. Use --enable-libfdk-aac.
• ​libvpx is a VP8 and VP9 encoder. Use --enable-libvpx.
• ​libvorbis encodes Vorbis audio . Requires ​libogg. Use --enable-libvorbis.
• ​libopus encodes Opus audio.
• ​LAME encodes MP3 audio. Use --enable-libmp3lame.
• ​libass is a subtitle renderer. Use --enable-libass.
• openssl and rtmpdump is used for --enable-librtmp.

        - configure

                因为`openssl安装在/usr/local/opt/openssl@3/`文件夹下，`pkg-config --list-all | grep ssl`找不到libssl, 所以添加PKG_CONFIG_PATH：`export PKG_CONFIG_PATH=$PKG_CONFIG_PATH:/usr/local/opt/openssl@3//lib/pkgconfig`

./configure  --prefix=/usr/local/ffmpeg --enable-openssl --enable-librtmp --enable-gpl --enable-nonfree --enable-libass \
--enable-libfdk-aac --enable-libfreetype --enable-libmp3lame \
--enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265 --enable-libopus --enable-libxvid --samples=fate-suite

出错查看ffbuild/config.log，有具体的错误原因 

         - make and install

make
sudo make install