5 ms·

The first one will re-encode.

• pvg 5y ago
  Right but it's conceivable the default behaviour might change, the explicit one is quite unlikely to.
  • _Gyan_ 5y ago
    It hasn't, since ffmpeg's inception. It's very unlikely - it would require that ffmpeg verify codec compatibility with the output muxer. Not all muxers have registered a codec tags list , so that can't happen.