After extensive testing, I might have figured it out.
Any JPEG image with truecolor, 100% JPEG quality, and >5 megapixels silently fails. It’s very specific but I’ll see what else I can do.
edit: I think I figured it out (again). Lemmy has a timeout of ~30s for images. It takes more than 30s for pictrs to process a JPEG image with the properties above (about ~45s). The image will be processed and can be accessed via its URL but Lemmy won’t return the URL because of the timeout. The timeout is actually hardcoded to 30s. I’m not sure why it’s hardcoded nor do I understand why it takes pictrs to process the image for so long (it only takes a second when I do magick convert image.jpg image.webp). I assume this is why videos don’t get processed either when I tested some time ago. Anyway, I’ll try to bring it up with the devs.
Could it be that it doesn’t handle images encoded as YCbCr4:4:4?
After extensive testing, I might have figured it out.
Any JPEG image with truecolor, 100% JPEG quality, and >5 megapixels silently fails. It’s very specific but I’ll see what else I can do.
edit: I think I figured it out (again). Lemmy has a timeout of ~30s for images. It takes more than 30s for pictrs to process a JPEG image with the properties above (about ~45s). The image will be processed and can be accessed via its URL but Lemmy won’t return the URL because of the timeout. The timeout is actually hardcoded to 30s. I’m not sure why it’s hardcoded nor do I understand why it takes pictrs to process the image for so long (it only takes a second when I do
magick convert image.jpg image.webp). I assume this is why videos don’t get processed either when I tested some time ago. Anyway, I’ll try to bring it up with the devs.