[Feature] Feature to select video preview image thumnail

I have searched the existing feature requests to make sure this is not a duplicate request. • Yes The feature Why is the preview image for saved videos inconsistent, and can we have a manual selection option? When saving videos, if the first frame is completely black, a preview image is often generated from a few frames later. However, this behavior is inconsistent. For example: In this video: the generated preview image looks like this: ![image]( In contrast, for this video: the first frame looks like this: ![image]( But the generated preview image ends up being this: ![image]( For some videos where the initial frame is a black screen, the frame a few seconds later is appropriately selected as the thumbnail, while for other videos, the first frame seems to be used. This inconsistency makes it difficult to predict or control the thumbnail. Suggestion: It would be helpful if users could manually select a specific frame of a video as a thumbnail, …