I have been having this problem for a long time and still can not find a fix for it. Anytime i'm working with some footage it would decide to start to glitch and pixelate, most of the pixels would try to overlap other parts of the footage then go back. whats even weirder is that if I check the preview of that specific layer the footage seems fine but when I go back to my compasition to see if it would be fine it goes back to being pixelated. sometimes I would unblur the edges and that would work in the preview but when I would export the video it ends up pixelated again. I tried most methods of purging the caches and turning off hardware acceleration, updating my graphics driver, I tried all of it but still no luck
Show us what is under the hood*. Cropped screenshots of the problem tell us nothing about your workflow or your comp.
Select the problem layers, press 'uu' to reveal all modified properties, make sure at least one of the footage layers is selected in the Project Panel so we can see what the footage is, make sure that both the switches and modes columns are showing so we can see blend modes, fx, and layer switches by turning on the first two column switches in the bottom left corner of the timeline, then take a full UI screenshot and embed it.
My first guess is 3D layers in the C4D workspace sharing the same plane. 3D layers in C4D comps must be separated by at least 1 pixel (usually in z).
My second guess, MP4 footage that comes from a screen capture or mobile device. My third guess, GPU rendering problems because of drivers or incompatibility. My last guess, your AE version is a previous build with a bug so Update to the latest build or if you did not have this problem with previous builds use the Creative Cloud app to roll back to a previous version.
* The "Drag & Drop here..." area is buggy and should not be used to share images. Please use the toolbar or just drag your images to the reply field.
Something like this? footage was taken from youtube. GPU is a xfx rx 580 8gb with the latest drivers
It looks like compression artifacts.
What was the original size of the downloaded video?
Did you download your files or did you do screen captures?
If the original footage was very low quality and/or dimensions and you are putting it into FHD, 1920 x 1080p Composition, then it could show undesirable artifacts.
I also note your screen grabs show >Untitled Project... I hope that means this is just a copy and that are saving your projects with meaningful file names!
original file was 64 mbs it wasn't screen recorded it was downloaded. footage origninal res is 1920 x 1080p
Try transcoding the screen recordings outside of After Effects and then use File > Replace Footage to swap the original clips for the transcoded clips.
Since you're on Windows, Handbrake is probably your best option.