[FFmpeg-user] MP4 from MXP - Material Package Only
Carl Eugen Hoyos
ceffmpeg at gmail.com
Sun Feb 17 22:19:04 EET 2019
2019-02-17 20:22 GMT+01:00, DeBacker, Bart <Bart.Debacker at turner.com>:
> We are currently using ffmpeg to extract a lower resolution MP4 file
> from our MXF OP1A standard hi-res files. This is the command:
>
> ffmpeg -i hires.mxf -s 960x540 -preset veryfast -framerate 29.97
> -f mp4 lowres.mp4
Complete, uncut console output missing.
It is probably a good idea not to specify an output format "mp4" if the
suffix of your output file is "mp4" (which implies the default output
format "mp4"), specifying it makes debugging more difficult.
Is "-framerate 29.97" supposed to have an effect?
The reason I ask is that there is no output option "framerate" and
that - most likely - the correct framerate is 30000/1001, not 29.97.
The name of the option to force an output frame rate is "r".
(I cannot know if you want your output to have the same frame
rate as the input - in which case you should not specify an output
frame rate - or if you need constant frame rate. To make this more
complicated, FFmpeg's mp4 output only supports constant frame
rate, so it may make sense to specify "-r 30000/1001" in any case.)
Carl Eugen
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