I just tried adding an .ogv clip in the timeline, and the thumbnails weren't showing; just white blocks. Reproducible: Always Steps to Reproduce: 1. Add an .ogv video clip to the Project Bin. 2. Insert video into the timeline. Actual Results: The thumbnails aren't there. Instead, there are white blocks. Expected Results: Should show thumbnails. Bug discovered while using Kdenlive via kdenlive-master ppa on Ubuntu GNOME 16.04 x64.
UPDATE: if it helps, these videos are made from gtk-recordmydesktop application, .ogv, 1920x1056, h.264 codec (I think). I can provide a link to download a sample video, if that helps, too.
This bug has been fixed in the latest git build. Marking bug as resolved.