Change Aspect Ratio without re-encode

[80r]

I just encoded a video with the correct resolution, but neglected to change the input DAR from 16:9 to 12:5, which the video should be. Is there a way I can fix this without re-encoding? The file is H264/MKV.

I searched around and found some answers, but I couldn't find a program that works for H264/MKV.

[Selur]

1. open the file with mkvmerge (mmg.exe; which is part of the mkvtoolnix package); drag&drop
2. select the V_MPEG4/ISO/AVC Stream than switch from gneral track-options to format specific options, specify the aspect ratio you want
3. Save the file under a new name (start muxing)

Assuming the player you use for playback properly supports mkv this should do the trick,..

[80r]

It worked! Thanks a lot!