How to save all the I-frames?

[version]

I have been using File > Save as Image to capture the I-frames.

Is there a way I can save all the I-frames at once?

Perhaps using command line mode?

[Jan Gruuthuse]

Maybe possible with ffmpeg, perhaps 2 steps
1st to video, then from new video to .jpeg
If it can work this way.

see:
- https://ffmpeg.org/ffmpeg-filters.html#select_002c-aselect
- https://ffmpeg.org/ffmpeg-filters.html#toc-Examples-119