[FFmpeg-user] Bug in I-Frame Retrieval?

[Zbigniew Zdziarski]

On 14-07-2014 14:29, Zbigniew Zdziarski wrote:
> Hello,
>
> I'm trying to extract I frames from mpeg files but I've noticed
> something weird happening. The frames that are saved in my folder by
> ffmpeg do not match the frames marked as I frames either by ffprobe 
> or
> ffmpeg with parameter "-loglevel debug".
>
> The command I'm using is the following:
>
> ffmpeg -i C:\vid1.mp4 -vf select='eq(pict_type\,I)' -vsync 0
> C:\%03d.jpg -loglevel debug 2> vid1.txt
>
> For some videos, the first few frames saved are correct. For some
> videos, all but the first frame are incorrectly saved.
>
> Is my command incorrect or is there a bug???
>
> Cheers,
> Zig
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I did some more digging around and found that this problem doesn't 
occur for all videos. E.g. the last 2 frames
saved by the command above for the following video are different to 
those marked as being I-frames:
https://www.scss.tcd.ie/~zdziarze/vid1.mp4

But all works fine for this video:
https://www.scss.tcd.ie/~zdziarze/vid6.mp4


Cheers,
Zig