Generally, following command can work:
ffmpeg -i [input file] [output file]
but in some machines, it well report an error like “Too many packets buffered for output stream 0:1.” and corrupt. Try this command:
ffmpeg -i [input file] -max_muxing_queue_size [Parameter] [output file]
the “parameter” can be any large value like “1024” or “2048”…