Question one; what is the unit used in the length? 128 in a previous example means 128 what? Milliseconds, frames?
Question two; what file type should be used for an animated painting? gif, mp4? It appears as if the mod won't accept file types that aren't .png but obviously you can't animate .png files.

128 pixels
file type used is .png. minecraft doesnt take gif or mp4

animated paintings use the same principle as animated blocks. its a file of all frames underneath each other
https://learn.microsoft.com/en-us/minecraft/creator/documents/createanimatedblocktexture?view=minecraft-bedrock-stable

Okay, 128 in length across width wise? So in a 1920x1080 image you would place 1080 in the file?
And is it a limitation that animated files can only be 1x1 not 1x2 or vice versa?

there is no limit on blocksize (1x1, 1x2)
I do not recommand using a HD image to make a painting or animated paintings of.

give the x and y values the size of the regular painting, and the anim value the size of the length of the actual file. this will allow the painting gui to crop your painting correctly and not have it show up squashed.

as stated in the wiki, the x and y values are the size of your actual painting (16x16, 16x32, ...)
the anim value is the length of the animatedi mage file > the link u send before, and generally how minecraft animated textures work, is to put all frames in a column in one file. so if your painting is 16x16 (1x1) and you have 8 frames, your file is 128 pixels long.
if you have 3 frames, your image will be 48 pixels long.

Okay. It's just a limitation of the GIF to Minecraft animated texture program I found that it has to be a 1x1 not a game limitation itself. If you know of a better one I would like to know. The only one that actually worked was called "AnimationCreator" from like 7 years ago or so. Haven't found a setting in it that changes the ratios or anything either.

if you are looking to turn a gif into a sequence of images that you can make a painting of,
try any free video editor on the web. most of them have a "export all frames" option. you could import the gif and export all frames in a batch, then use a tool like Gimp (image editing software) to paste them one under another

Okay thx, I will give that a shot. Is there a way to quick move the frames under each other? As one of the videos I am trying to animated is 800 frames and I'd rather not manually fit 800 frames into the program.