Solved by update to MW.

Seems to work!

The only thing I will mention on this is that archive.org, which is one of the main sources for URL-based uploading, can have slow (sometimes extremely slow) download times. So perhaps the download stage, when the size of the file has been announced by the host from which it is being downloaded, should be allowed to proceed until the download has completed (for async jobs).

Even if the speed of the connection to IA had been unlimited (or there had been no timeout for that portion), wouldn't the operation still fail at the publication stage?

@Bawolff To be clear, I first tried async publication, and only later tried a non-async to see if it would work. But async from stash is what I was trying multiple times and it just didn't work. I also tried async from archive.org, too, but (unsurprisingly) that didn't work either.

The notion that YouTube videos must be converted to a free format is a misconception. YouTube already prefers VP9/Opus in WebM as its delivery format. Also, YouTube Premium, though it allows downloading of videos, doesn't allow for them to be downloaded as files on the user's filesystem, whereas yt-dlp does. So those two points aren't material.

The "according to the same reasoning almost everywhere" is doing a lot of work, because it is far from established that any other court (in a different country, with different laws) would necessarily come to the same conclusions.

I would suggest, by the way, that the original file be conserved on the server side, in part to allow for potential better re-encodes in the future (as well as release of the original, once the codecs are free).

Btw, when this goes live (on Commons and on enwiki), can you let me know?

@C.Suthorn, I think you're conflating two issues here (and this makes some sense, because V2C does two separate things which might be problamtic).

I also frequently get

Anecdotally (from uploading some large videos), I find that somewhere between 4 and 5 GB, the failure rate goes from pretty low to ~100%. Like, I have no issue uploading a 3.85 GB video. I can't upload a 4.85 GB video. Basically, this is really just a problem when I am uploading my AV1 encodes of feature films, which can really benefit from getting as close to 5 GB as possible.

Another typical error:

I've tried numerous times with the chunked uploader. I am able to get the files to upload to the stash perfectly reliably, but every attempt to get the file to publish (via async + MW API sandbox) fails. Always just fails at the publish stage. I've tried a bunch of times over the past few days, and so I'd hope that it would work, but I just couldn't get it to... I keep getting stashfailed timeouts when trying to publish. This is probably because these files are large (close to, but not above, the upload limit).

It can't be using grain synth in the output, because it is encoding VP9 (and some other non-AV1 codecs), which doesn't have a grain synthesis feature like AV1.

As a photographer who has a few thousand of his own photos on Commons: I'd support adding AVIF, and I would use it if available.

Might the issue be related to which decoder ffmpeg uses for AV1 (libdav1d or libaom-av1)? I've been using libaom-av1 for decode in the build of ffmpeg I'm using locally.

Uploaded a 1-minute test file (AV1 with FGS). Video transcodes all error out (on both enwiki and commons).

Yes, the film grain features of AV1 were used in encoding. I had no issue using ffmpeg with this clip on my local machine; could this be an issue in an older version of ffmpeg deployed on WMF servers?

Don't know if it is AV1 that is causing the issue, but for comparison, https://commons.wikimedia.org/wiki/File:The_Kid_(1921).webm is also an AV1 file (actually, both a larger file overall and with almost 5 times the bitrate) and it transcoded just fine (uploaded on January 12).

Please add

For non-stash and async... here's an example of a failed upload (same error occurs whether the chunk size is large or small).

In T355031#9531204, @Racconish wrote:

Not sure such an upload would be fair use.

<edit> I added another file, but got it to upload myself after multiple tries.

To add: