Hello, I have a camera recording which is an MXF file and the codec is DNxHD I suppose it is a single-frame codec so literally it is a container of images which are independently stored in the file. Recordings are taken at 50 fps progressive. Now what I want is to extract only half of the frames, so that it becomes 25 fps Note that I need to do it _without re-encoding_ for two reasons: 1. Conversion must be as fast as possible, files can be really huge 2. No changes to original information should occur
Theoretically this is an elementary operation, it should just take every second frame from source and write to output leaving everything else as is. I have tried several options whith "-r ..." and added "-c:v copy" These commands I have tried: ffmpeg -i Capture0006V_720p.mxf -r 25 -c:v copy out1.mxf ffmpeg -r 50 -i Capture0006V_720p.mxf -r 25 -c:v copy out1.mxf ffmpeg -r 2 -i Capture0006V_720p.mxf -r 1 -c:v copy out1.mxf But they all produce again 50 fps video, so I suppose stream copy just ignores all "-r" options so I don't know what can I do to achieve what I want. I have searched a lot, so I've registered here hoping for solution. Is it possible that ffmpeg cannot do this without re-encoding? If no, how can one do this? Thanks in advance. _______________________________________________ ffmpeg-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email [email protected] with subject "unsubscribe".
