Encountered a similar issue today that was corrected with information from ffmpeg issue 963: https://roundup.ffmpeg.org/roundup/ffmpeg/issue963
The input mkv I was working with had > 20 streams; changing MAX_STREAMS to 64 in libavformat/avformat.h in a recent checkout and rebuilding corrected the issue.
Encountered a similar issue today that was corrected with information from ffmpeg issue 963: https:/ /roundup. ffmpeg. org/roundup/ ffmpeg/ issue963
The input mkv I was working with had > 20 streams; changing MAX_STREAMS to 64 in libavformat/ avformat. h in a recent checkout and rebuilding corrected the issue.