get_children mime type video

What specifically do you want to do? If you save video thumbnails as children of the video (this is an option in the plugin settings), you could do something like

get_children(
     post_parent => $video_id,
     post_mime_type => 'image'
);

and that would get any image whose parent is that particular video.

The thumbnail ID is also saved in the video’s post meta field _kgflashmediaplayer-poster-id

Hi, thanks for getting back to me!
So here’s a link where you can see what I’m trying to do.
https://jennynordberg.se/the-blocket-series-2005-2011-2011-2/
The images are pulled from the post and I want to add video thumbnails at the end of that.

Regards
Marcus

Which video thumbnails? Video thumbnails attached to that post or thumbnails of videos attached to that post? You could choose to save the video thumbnails as children of the post instead of children of the video. I can’t tell from that page what thumbnails you have available and how they are saved.