*.mp4 doesn't show as thumbnail,
*.gif readily shows as thumbnail for posts,
Tested a few times, in post's URL field.
( *.gif has to be on external web site )
Maybe this is already in the list of improvements to be made ?
What, really? I may be showing my age here but I always assumed that gifs, comprising nothing but a series of pictures, are way less complex than any video format, which is made to accommodate audio and subtitles and whatnot. Has that changed sometime in the last 20 years?
Gifs as an image file format has very poor compression, particularly for complex images. Each frame only contains the parts that are changed from the previous one, so simple graphics with only small parts that change work well. When the image starts getting larger and more detailed, proper video compression becomes much more efficient.
GIFs are an average of 5-10 times larger than an efficiently encoded MP4 video
So an automated process like Lemmy uses is efficient enough to do that? In my head, there exists a brain, somewhere, and I can't even get digital copies of my dvds down to any manageable size without fiddling with Handbrake endlessly.