I have numerous 50Mbps IMX50 wrapped MXF videos. Media info/media tab read the aspect ratio as 4:3. I'd like to change that to 16:9. Ideally I would not re-encode all the content because I have 1000s of hours of content to apply this to. Ideally ffmpeg would just perform the data modification to switch the aspect ratio to 16:9.

I used the command below and it changed the aspect ratio but it then made my bit video rate 200Kbps and removed 3 of my 4 audio tracks but left the audio bit rate untouched. The video and audio codec remained the same. I'd like the bit rate and number of audio tracks to remain untouched; again without re-encoding if possible.

ffmpeg -i input.mxf -vf setdar=16:9 output.mxf

I also found that I can't use the -vcodec copy and -acodec copy with the filters (-vf).

Is there a way to use the setdar parameter and retain the original audio and video codec settings?

  • This information is not part of the actual encoded frames, but bitstream data (which codec, btw?) that could theoretically be changed without re-encoding the footage. But I'm not aware of any tool that can do that. – slhck Aug 11 '17 at 10:48
  • @slhck - for H.264 streams, see forum.doom9.org/showthread.php?t=152419 – Gyan Aug 11 '17 at 13:23

No. At best you can try

ffmpeg -i input.mxf -map 0 -c copy -aspect 16:9 output.mxf

However, setdar is a filter and so, if used, the video will have to be re-encoded.

  • Thanks Mulvya. That's what I was afraid of. I had tried what you suggested before but it didn't work. I'll keep searching for another option. Re-encoding would take months. Thank you. – Halo Aug 11 '17 at 13:17

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