[FFmpeg-user] Image extraction broken with ffmpeg, but not with mencoder. How can I fix this?

James Board jpboard2 at yahoo.com
Thu Sep 5 20:28:30 CEST 2013

Let me try a different tact and explain what I'm doing in the
big picture.  I wrote a Video Editor to edit my videos.  It takes
a sequence of images as input, displays them on the screen.  I
can then play forward and backwards in that sequence, and select
Start/End frames, and delete those sequences.  The output of the
whole process is a file, which has a list of Start/End frame numbers
for the segments to be included in the output video.  I then take
those Start/End numbers and use them with ffmpeg's select
filter to actually perform the edits.

So, in order for me to use timestamps, I have to be able to convert
a frame number to a timestamp.  I'm not trying to upset you.  That's
just what my application requires.

You say timestamps are properties of frames, and I 'just read them'.
Where do I read them from?  Can I run some ffmpeg command that
prints the timestamp for every frame?

>No, your video is not 29.97 fps; it has probably 1001/30000 as a time base.

You are correct.  It isn't 29.97.  It's closer to 29.97002997002997.....
So, I rounded off.  Isn't this ironic?

Thanks for trying to help.

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