Safari Users Unable to Play Newer 4K Video On YouTube in Native Resolution (macrumors.com)
It appears Google recently turned on VP9 codec on YouTube for delivering 4K video. However, because of this, Safari users are unable to watch videos uploaded to the service since early December in full 4K resolution. From a report: Specifically, YouTube appears to be storing video on its servers using either the more efficient VP9 codec or the older H.264 codec. Safari only supports the latter, which explains why recently uploaded 4K videos are only able to be viewed in up to 1440p. Funnily enough, the same videos can be streamed by Safari in native 4K as long as they're embedded in another website, suggesting that the VP9 codec support requirement only applies to videos viewed directly on YouTube's website. Until Apple updates Safari to support the VP9 codec, Mac users who want to access newer 4K video on YouTube in native 2160p resolution are advised to use a different browser.John Gruber of DaringFireball writes, "I'm curious what Google's thinking is here. My guess: a subtle nudge to get more Mac users to switch from Safari to Chrome. 4K playback is going to require H.264 support if they want it to work on iOS, though."
Closed Source Problems.
This says more about the sad state of the web than anything else.
Remember the big stink that was made about video support on HTML5? How it was going to make flash obsolete and whatnot?
Well, you should look at a matrix of supported formats for HTML5 video. Long story short, only h.264 is well supported out of the box by every browser (desktop + mobile).
VP9 and Theora are not supported by Edge nor Safari. h.265, IIRC, needs plugins on Firefox and Chrome. The picture is even bleaker on mobile.
Codec support is all over the place. It's a fucking mess.
Sadly enough, flash is still the only full proof way of displaying video (with controls that don't suck, but that's another issue).
Because a Lightning adapter is cheaper than an Apple TV.
But then because of limited throughput over Lightning, the Lightning adapter uses AirPlay protocol anyway, and it isn't even full 1080p.
4k is good for video editing, it is good if you watch blockbuster movies on a bigass screen, but for YouTube videos on your computer, really? It is a tech demo, there is little use for it.
To enjoy 4k, you need a monitor that supports it, that is large enough relative to the viewing distance, enough bandwidth and processing power. You also need a 4k source. Few people produce 4k video : it is more expensive, more difficult and the result is only marginally better.
If you manage to check all the boxes, then the browser is the least of your worries.
One day, maybe 4k will actually bring something, but it is a bit too soon. Still, it's interesting how far ahead Apple is when it comes to removing stuff (floppy drive, ethernet port, headphone jack, ...) but not so much when it comes to actually support the technology of the future.