Why is it that I can post the attached mp4 but not the source as a gif?

To make the mp4 I encoded the gif in handbrake, which actually made increased the file size but reduced the dimensions.

Source gif:  728*408, 785.5 KiB
Encoded mp4: 640*360, 836.7 KiB
  • tal@lemmy.todayEnglish
    0·
    10 days ago

    On size, Lemmy uses pict-rs. There’s a per-instance-settable byte limit max on the max file size that can be uploaded to a pict-rs instance. I’ve got no idea whether it supports animated gifs.

    EDIT: So, a bit of experimentation later, Pict-rs does take WebM. And WebM can contain AV1-encoded stuff, which can be lossless. But AV1 doesn’t appear to be optimized for GIF-style flat color images, the way MNG and APNG are. Still, you can get a (larger) file which a pict-rs instance will accept as long as it doesn’t hit the filesize limit, which represents the video in the GIF file without loss:

    $  stat --format=%s ibjtdug-imgur.gif
804394
$ ffmpeg -i ibjtdug-imgur.gif -c:v libaom-av1 -aom-params lossless=1 ibjtdug-imgur-av1-lossless.webm
$ stat --format=%s ibjtdug-imgur-av1-lossless.webm
1856545
$

    That slightly more than doubles the filesize.

    That being said, I will point out that GIF itself really isn’t a great format for this. Like, the reason that many codecs won’t do well with this is because they deal poorly with dithered images. The original data (the original original data, pre-GIF-encoding) isn’t dithered, and got smashed down to 256 colors and an ordered dither when it was encoded as a GIF, and it’d probably be preferable to not dither it; using that would probably result in a better-quality and smaller video.