[FFmpeg-user] Selecting/dropping frames without re-encoding

[Carl Eugen Hoyos]

2016-10-06 16:16 GMT+02:00 Mikhail V <mikhailwas at gmail.com>:

> I admit I am not fully getting your idea then.

Your original email (and subsequent ones) sounded as if you knew
exactly what has to be done, you were just asking if it is possible
without a little shell magic (I think it is not).

You can do:
$ ffmpeg -i input -vcodec copy -f image2 frame%4d

Now make symbolic links to every second frame but
with sequential numbers (Don't ask me how).
$ ffmpeg -f image2 -vcodec dnxhd -i linked_frames%4d -vcodec copy out.mxf
(25fps is the default for the image2 demuxer, use -framerate to change it)

Or simply concatenate the frames you like with "cat" and do:
$ ffmpeg -i concatenated_file -vcodec copy out.mxf

Carl Eugen