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node.jsffmpegoggfluent-ffmpeg

ffmpeg output files differ

The following code outputs differing files. Why?

I used both the diff command and cmp which says they start to differ at byte 15. I also tried changing the argument to toFormat() from 'ogg' to 'mp3'. Same results. 

ffmpeg( './original/test.mp3' )
    .toFormat( 'ogg' )
    .on( 'error', function(error, stdout, stderr)
    {
        console.log( 'Cannot process file: \n' + error );
    })
    .output( './tmp_a/' + filename )
    .output( './tmp_b/' + filename )
    .run();

I can't tell if I'm doing something wrong or if this is expected behavior.

Solution

  • The OGG format muxer writes a unique serial number or ID tag. Add -flags +bitexact to set it to zero.