https://www.ffmpeg.org/doxygen/trunk/ac3dec__fixed_8c.html
FFmpeg: libavcodec/ac3dec_fixed.c File Reference
ffmpegfixedcfile
https://www.ffmpeg.org/doxygen/trunk/ac3dec__fixed_8c_source.html
FFmpeg: libavcodec/ac3dec_fixed.c Source File
ffmpegfixedcfile