Reside streams will begin trying a complete lot nicer quickly. YouTube has begun rolling out assist for an up to date streaming protocol, which when paired with the upcoming OBS Studio 29.1 replace, will permit customers to broadcast AV1 video, a.ok.a. the way forward for GPU streaming.
The advance is so substantial that customers can stream great-looking 4K 60FPS video at simply 6 megabits per second – a bitrate that traditionally been deemed “not enough” to supply high-quality 1080p streams in H.264 over on Twitch.
What’s AV1?
At simply 10mbps, an AV1 YouTube stream at 4K 60FPS appears to be like far superior to most 1080p 60FPS Twitch streams at 6mbps.
Adam Taylor / IDG
AV1 is a brand new, open supply video codec that goals to dethrone H.264 as the first video commonplace after its practically 20 year-long reign. AV1 is developed by the Alliance for Open Media – a consortium backed by plenty of main tech companies adjoining to streaming and video, together with the likes of Google, Netflix, Arm, Apple, Amazon, Intel, Microsoft, and Nvidia.
The AV1 encoder has been very powerful to run at excessive speeds when operating in software program in your CPU, however the previous couple years have seen large enhancements to the effectivity of the accessible encoders. Over the previous 9 months we’ve gotten graphics playing cards from AMD, Intel, and Nvidia which have {hardware} AV1 encoding built-in, permitting customers to encode AV1 video in real-time with minimal efficiency penalty.
Enhanced RTMP
For the primary time in 10 years, the RTMP streaming protocol spec has obtained an replace, dubbed “Enhanced RTMP.” The spotlight from this replace is assist for extra video codecs: HEVC/H.265, VP9, and AV1. YouTube helps RTMP.
HEVC was already supported by YouTube utilizing the HLS protocol – however that protocol didn’t at all times play properly with some web connections and sometimes introduced greater latency to getting streams to viewers. Enhanced RTMP appears (in my testing) to hold the identical latency that standard RTMP streaming had.
OBS 29.1
Adam Taylor/IDG
Within the upcoming OBS Studio 29.1 replace, customers will be capable of use these codecs by deciding on “YouTube – RTMPS” in Stream settings. Then any accessible HEVC and AV1 encoders will probably be made accessible, together with the SVT and AOM CPU-based AV1 encoders.
Adam Taylor/IDG
On the time of testing, solely Nvidia and Intel {hardware} AV1 encoders are supported, however AMD assist will probably be coming shortly.
Graphics playing cards that assist AV1 encoding:
It’s additionally price noting that Nvidia GeForce RTX 3000 and AMD Radeon RX 6000 graphics playing cards assist AV1 decoding for playback, however don’t assist encoding on {hardware}.
Customers of graphics playing cards going again to even Nvidia’s older GTX 10-series (GTX 1050 ti and better) will be capable of stream HEVC with this replace, nevertheless, bringing greater high quality streams to older GPUs too!
Decrease bitrates
In my testing over the course of a number of multi-hour streams, you possibly can obtain top quality, clear video with far decrease bitrates than ever earlier than.
Streaming 1440p 60FPS can look nice with simply 4-8mbps. 4K 60FPS can look nice with simply 10-20mbps. That is really game-changing—each for folks with restricted add bandwidth and people with not a lot laborious drive area for recording capacities.
Presently, AV1 streams to YouTube are usually not delivered to viewers in AV1. As YouTube at all times transcodes the movies and streams it ingests (in comparison with Twitch, the place the default is “Source Quality” untouched by compression), streams at greater than 1080p decision (1440p and 4K) will probably be delivered to viewers in VP9, and 1080p and decrease streams will probably be delivered in both AVC (H.264) or VP9, relying on viewership. This doesn’t considerably impression high quality greater than anticipated, and VP9 does an important job at preserving picture integrity over blocking and artifacts.
This isn’t a great-looking stream, nevertheless it’s fairly acquainted to those that browse random Twitch streams. However this isn’t the everyday 3.5-4mbps Twitch stream, that is 1440p60 at a mere 500kbps streamed to YouTube!
Adam Taylor/IDG
In my testing, I did discover that the assorted AV1 encoders did battle to stay to their exact-specified CBR targets I entered in OBS – nevertheless it wasn’t an enormous difficulty, and the general gained headroom makes up for it.
I even examined as little as 500kbps for 1440p60 and whereas it was clearly a pixelated mess, my viewers decided it was nonetheless surprisingly watchable in comparison with a whole lot of present 1080p Twitch streams.
The Way forward for Streaming
This can be a large win for YouTube and instantly begins permitting creators to avoid wasting on bandwidth and achieve high quality inside their dwell streams. As {hardware} continues to enhance AV1 efficiency, an increasing number of streamers will begin utilizing this characteristic.
However some questions on the way forward for AV1 implementations nonetheless stay.
Alliance for Open Media
First I’ve to marvel, when will Apple begin supporting AV1? Apple is an early AOM member, having joined in 2018, however they’ve by no means as soon as listed AV1 decode assist inside their {hardware} specs—even when loads of recreation consoles, good TVs, and different Android gadgets have carried out a number of generations of assist. Realizing Apple, I wouldn’t be shocked if they’re ready on the “right moment” to announce that the present era (be it M2 or iPhone 14 or 15, no matter is the most recent era on the time) of {hardware} has had AV1 assist this complete time and so they’re simply now turning it on—most likely introduced at WWDC or one other related occasion. However so far, they’ve been silent on the subject.
Talking of silence, there’s additionally the query of Twitch. The streaming large has been fairly quiet about their unique AV1 Roadmap since their Precept Video Engineer Yueshi Shen left for TikTok in 2021. I hope AV1 continues to be on monitor for Twitch, particularly since an up to date RTMP spec ought to be simpler to implement than a complete new protocol. Sadly, we’ve no method of understanding at the moment. Including to the discomfort, Video Encoding and Playback Software program Engineer “M3U8” suggests Twitch has a lot of labor forward of them to implement this replace:
Ought to Twitch nail AV1 assist someday quickly, they could have a bonus over YouTube for visible streaming high quality for the primary time. Since Twitch defaults to “Source” high quality – a stream that isn’t compressed between streamer and viewer – the benefits of low-bitrate AV1 streaming will probably be way more obvious to the viewer than the identical stream transcoded by YouTube’s VP9 encoders.
Solely time will inform, however competitors is ramping up. Take pleasure in these drool-worthy YouTube AV1 streams!
