[FFmpeg-user] Image extraction broken with ffmpeg, but not with mencoder. How can I fix this?
Paul B Mahol
onemda at gmail.com
Mon Sep 2 21:39:57 CEST 2013
On 9/2/13, James Board <jpboard2 at yahoo.com> wrote:
>>> Please tell me I didn't waste 4 hours because of an ffmpeg bug.
>>You never mentioned what you are actually doing.
> I'm converting a video file to a sequence of image files. I used both
> ffmpeg and
> mencoder (actually, mplayer) (I mentioned this is the first line). Here is
> an example:
> ffmpeg -i IN.avi -q:v 4 -f image2 %08d.jpg
>>For image demuxer you need to set input frame rate or default one
>>will be used, which may not be what you want.
> The image2 muxer documentation doesn't mention this. How do I
> specify an input frame rate (24000/1001) for the above command?
You need it for whatever reads images not for creating them....
So it is needed for DEmuxer, not for muxer (unless you want to
dupe/remove random frames).
> Also, I have a huge edit list which took 4 hours to generate. Is there
> some formula I can use which will convert the frame numbers that ffmpeg
> used as output for the jpeg images to the equivalent frame numbers that
> will use as input to the select filter?
Use same frame rate for input as for output, its simple enough.
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