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

[Zbigniew Zdziarski]

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