This is a combination of a bug report and a feature request.

Currently it appears that there are two thumbnail modes.

1/ Most often there are just two thumbnails for each clip, one at the beginning, one at the end.

2/ When zoomed right in, every individual frame is shown as a thumbnail.

I would like something in between. There should always be several thumbnails. Probably the exact number

would be user configurable,, but I think choosing thumbnails so that about 2/3ths of the line was thumbnails

and 1/3 was space between thumbnails would look quite good. This would be the same no matter how

much zoom was imposed.

The bug is that currently, when you zoom right in, it seems to render all of the thumbnail. So if I have a very large

clip (20minutes) kdenlive stops responding for a few minutes while the thumbnails are rendered.