I'm maybe missing something, but: the article states that Android previously provided an AV1 software decoder. New versions of Android ship a new software decoder called "libdav1d", which is currently opt-in - apps that don't opt in will get the old decoder. Youtube has opted in to using the new decoder.

But… doesn't this just mean that devices that were previously decoding AV1 Youtube streams in software will now decode them using a more efficient decoder? It doesn't say anything about Youtube changing the default stream format. Am I missing something?

3840x2160 resolution on a mobile screen seems just plain dumb and wasteful to me, and I have really exceptionally good vision. Even on a 27" monitor I can just barely see the pixels at that res.

I agree, but with an important caveat: Youtube's 1080p streams are over-compressed. I have a 1080p projector, but 4K Youtube videos still look noticeably better due to the higher bitrate.

Admittedly this is on a huge projector and not a phone. I don't watch enough Youtube videos on my phone to know if it would matter there.

They added a high-bitrate 1080p option on some videos for YouTube Premium subscribers.

That's nice, but a little odd that it's paywalled when the 4K option is not.

There is a small benefit as some videos have "enhanced 1080” but no higher resolutions.

Afair Apple users also get those higher bitrates by default, for free.

I don't know what you're responding to? This isn't moving anyone new to 4K, just making 4K more efficient when it is utilized.

The very first sentence in the article (summary) is about 4k video, and it's supposedly something mobile users are whining about:

> With the rise of 4K video, the AV1 codec is becoming popular for better quality on Android devices.

So I don't get why people are putting themselves in that situation in the first place. It's like choosing to use a fork to row a boat and then going waaaahhhh this isn't working very well... no shit, wrong tool for the job.

They will use the same codec for a variety of resolutions and bitrates. The article mentioned most devices supporting 720p30.

It likely vastly simplifies their backend to use one codec for everything.

My phone screen pixels often occupy a larger angle of my vision than my 4k TV on account of being less than a foot from my face instead of 10 feet away.

A lot of Youtube videos I saw don't have AV1 option (check with yt-dlp --list-formats). So are they going to re-encode everything now?

They might. Especially if they are popular.

It is a certainty that, some time in the future, the bandwidth cost of not re-encoding will exceed the one-time cost of re-encoding.

How far in the future probably informed this decision.