[FFmpeg-user] Setting Display Aspect Ratio of MXF/DV video
ch0d4 at free.fr
Tue Apr 14 10:25:10 CEST 2015
> For future questions, please always test current
> FFmpeg git head.
> (Nothing else is supported here.)
Sorry, I obviously forgot to mention that I had re-run the tests with
the 20150413 static build (based on git g013498b) which was the
latest available at the time I wrote my message.
>> Stream #0:0: Video: dvvideo, yuv420p, 720x576 [SAR 16:15 DAR 4:3]
>> A bit of context: the input file is supposed to
>> be broadcasted in 16:9, but as you can see it
>> is reported as 4:3 by ffprobe.
>I am not sure I understand:
>Do you mean that FFmpeg detects the aspect ratio
>incorrectly? If yes, this should be fixed first
>(and all remaining issues depend on this).
FFmpeg is not at fault: the original file was erroneously generated
in 4:3 by the content provider while it should have been created in
16:9. I was just explaining why I needed to fix the aspect ratio.
>> $> ffmpeg -i in.mxf -vcodec copy -aspect "16:9" -an out_copy.mxf
> This does not work because libavformat writes
> mxf aspect ratio differently from all other
> containers (sadly).
> To some degree this is related to the fact
> that mxf aspect ratio is defined in a rather
> brain-dead way.
Ok, thanks for the info.
>> At this point, my understanding is that
>> the MXF container is always assigned a
>> display aspect ratio of 4:3, even when it
>> should be assigned 16:9.
>This is certainly not true but as said, mxf
>aspect in FFmpeg on muxing is different
>from other containers.
>(And this is a bug imo.)
This was just a straightforward conclusion of mine, since I couldn't
get it to work as it did with other containers. You made it clear
that it actually works differently.
I guess for now for I'll just stick with FFmbc for this peculiar
Thanks for your answer.
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