If you insert a video file into Impress 18.104.22.168 (on ubuntu 14.04 64bit) and run the screenshow, the video plays as expected. However, if you save the presentation and exit impress and reopen impress and load the presentation the video is missing.
This occurs with both ppt/pptx file formats with Impress 22.214.171.124.
I believe the same issues are present in the previous versions of impress as I could never have a embedded video file, so had to resort to animated gifs. Having a link to a presentation isn’t an option.
Unclear why this problem hasn’t been picked up and resolved previously and was hoping 5.1 had the resolution