Some AVIFs fail to embed successfully

[juliobbv-p]

1. Download this image (rename extension to .avif after download)
2. Upload image to Discord

Expected

Image embeds successfully

Observed

Image fails to embed, leaving just a download link

Notes

This image happens to be a SDR image, but in 10 bit format. I've noticed that there are a few other images of this kind (but not all of them) that fail to embed in a similar way, so that might be a lead.
10 and 12 bit SDR images are valid in the AVIF format, and are preferable as higher bit depths are superior at handling gradients. See this issue for an example.

[skidder]

Thanks for filing this issue @juliobbv-p !

The problem is that the source image pixel-count exceeds the 15 million pixels, the maximum allowed for Discord image embeds. This is a safe-guard to provide some kind of upper bound on the size of images we'll transform.

Discord's current max is 15 million pixels. The image you linked is 31,961,088 pixels (4896px x 6528px). Our current limit of 15M pixels should comfortably allow for 4K (3840px x 2160px, or 8,294,400 total pixels) uploads.

I'm sorry about the inconvenience - it seems like Discord could improve the error message for this situation, maybe including a message along with the attachment indicating it's too large to show as an embed. wdyt?

[juliobbv-p]

Hi @skidder,

Thanks for following up! I guess my source of confusion is that some of the bigger images do seem to embed, but there's currently no straightforward way to know ahead of time whether it'll embed or not. For example, this AVIF is also 4896px x 6528px, but it does embed. Do you think if there could be a timeout limit at play as well?

For the message, Discord could warn the user if the image to embed is over 4K. That should make it clear enough what's happening under the hood. Does that sound good?