Live streams will begin wanting a complete lot nicer quickly. YouTube has begun rolling out help 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.k.a. the future of GPU streaming.
The enchancment 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 is AV1?
At simply 10mbps, an AV1 YouTube stream at 4K 60FPS appears 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 normal after its almost 20 year-long reign. AV1 is developed by the Alliance for Open Media – a consortium backed by a number 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 big 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 help 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 all the time play properly with some web connections and sometimes introduced increased 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
In the upcoming OBS Studio 29.1 update, customers will be capable of use these codecs by deciding on “YouTube – RTMPS” in Stream settings. Then any accessible HEVC and AV1 encoders can be made accessible, together with the SVT and AOM CPU-based AV1 encoders.
Adam Taylor/IDG
At the time of testing, solely Nvidia and Intel {hardware} AV1 encoders are supported, however AMD help can be coming shortly.
Graphics playing cards that help AV1 encoding:
It’s additionally value noting that Nvidia GeForce RTX 3000 and AMD Radeon RX 6000 graphics playing cards help AV1 decoding for playback, however don’t help encoding on {hardware}.
Users 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 increased high quality streams to older GPUs too!
Lower bitrates
In my testing over the course of a number of multi-hour streams, you’ll be able to 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. This is really game-changing—each for individuals with restricted add bandwidth and people with not a lot arduous drive house for recording capacities.
Currently, AV1 streams to YouTube aren’t delivered to viewers in AV1. As YouTube all the time transcodes the movies and streams it ingests (in comparison with Twitch, the place the default is “Source Quality” untouched by compression), streams at increased than 1080p decision (1440p and 4K) can be delivered to viewers in VP9, and 1080p and decrease streams can be delivered in both AVC (H.264) or VP9, relying on viewership. This doesn’t considerably influence high quality greater than anticipated, and VP9 does a fantastic 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. But 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 varied AV1 encoders did battle to stay to their exact-specified CBR targets I entered in OBS – nevertheless it wasn’t an enormous concern, 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 Future of Streaming
This is a large win for YouTube and instantly begins permitting creators to avoid wasting on bandwidth and achieve high quality inside their stay streams. As {hardware} continues to enhance AV1 efficiency, increasingly more streamers will begin utilizing this function.
But 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 help inside their {hardware} specs—even when loads of sport consoles, sensible TVs, and different Android gadgets have applied a number of generations of help. Knowing Apple, I wouldn’t be shocked if they’re ready on the “right moment” to announce that the present technology (be it M2 or iPhone 14 or 15, no matter is the newest technology on the time) of {hardware} has had AV1 help this complete time they usually’re simply now turning it on—most likely introduced at WWDC or one other comparable occasion. But up to now, they’ve been silent on the subject.
Speaking of silence, there’s additionally the query of Twitch. The streaming big has been fairly quiet about their original AV1 Roadmap since their Principle Video Engineer Yueshi Shen left for TikTok in 2021. I hope AV1 continues to be on observe for Twitch, particularly since an up to date RTMP spec ought to be simpler to implement than a complete new protocol. Unfortunately, we’ve got no method of understanding presently. Adding to the discomfort, Video Encoding and Playback Software Engineer “M3U8” suggests Twitch has a lot of labor forward of them to implement this replace:
Should Twitch nail AV1 help 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 – some great benefits of low-bitrate AV1 streaming can be rather more obvious to the viewer than the identical stream transcoded by YouTube’s VP9 encoders.
Only time will inform, however competitors is ramping up. Enjoy these drool-worthy YouTube AV1 streams!