[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 21:02:22 CEST 2013

On 9/2/13, James Board <jpboard2 at yahoo.com> wrote:
> If I convert a rawvideo, or ffvhuff-compressed AVI file to images
> with both ffmpeg and mencoder, the images are not the same.   For
> example, image 1000 from the mencoder output might correspond
> to image 998 from ffmpeg.  As the image number gets higher and
> higher, they diverge further.  The results are not consistent from one
> video file to to the next.
> This is causing my problems with incorrect cut edits:
> The ffmpeg select filter is counting frames differently then the
> ffmpeg image demuxer, or whatever you call the component that
> ffmpeg uses to convert video into image files.
> Why is this happening?  Is it possible that ffmpeg doesn't handle dropped
> frames correctly?  Is there any easy way to fix this?  I spent several
> hours editing video based on what now seems like incorrect frame
> numbers.  Is there a way I can get ffmpeg to tell me when it dropped
> a frame so that the output agrees with mencoder, which is correct?
> Please tell me I didn't waste 4 hours because of an ffmpeg bug.

You never mentioned what you are actually doing.

For image demuxer you need to set input frame rate or default one
will be used, which may not be what you want.

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