This text gives a fast overview of the AV1 codec: what it’s, the way it performs, what it prices, and what it’s good for. As you’ll be taught, the AV1 codec is difficult to transcode in actual time at this cut-off date, so it doesn’t play a task in lots of dwell workflows, excepting some WebRTC implementations. Encoding price and the codec’s restricted however rising attain additionally slim the related scope of video on demand (VOD) functions. As you’ll learn, even YouTube solely makes use of the AV1 codec on movies which can be watched a number of tens of millions of occasions.

On the time of this writing, AV1 isn’t supported in any of Wowza’s services or products. 

What Is the AV1 Codec?

The AV1 codec is the primary codec shipped by the Alliance for Open Media (AOM), a consortium of streaming firms anchored by founding members like Amazon, Apple, Cisco, Fb, Google, Intel, Microsoft, Mozilla, Netflix, NVIDIA, and Samsung. AOM was introduced in September 2015. The group shaped as a result of member firms like Google had been pissed off that they didn’t have related enter into standards-based codecs, and since many within the founding group had been involved about complicated and overreaching HEVC royalty insurance policies. As well as, three of the founding firms had been individually working in the direction of an open-source codec — Google (VP10), Cisco (Thor), and Mozilla (Daala) — so it made sense to affix forces and produce a single open-source code.

AV1 was finalized and launched round Might 2018. On the time, AOM members predicted immediate assist inside most member firm’s browsers, and a two-year adoption cycle for cellular and OTT functions. AV1 assist inside Chrome, Edge, and Firefox got here in a short time, and the primary Sensible TVs with AV1 assist shipped in early 2020 as predicted. Nevertheless, cellular {hardware} deployments look like pushed out to 2026-2027 (see David Ronca’s interview with John Porterfield right here, about 31 minutes in), altering the cellular technique from {hardware} assist to software program assist.

To this point, AOM has printed 5 specs, for the AV1 Bitstream, AV1 in ISOBMFF, ID3 Timed Metadata, AV1 Picture File format, and RTP payload Format for AV1 (draft). In response to AOM documentation, every AOM licensee will get “a non-sublicensable, perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable (besides as expressly acknowledged on this License) patent license to its Needed Claims to make, use, promote, provide on the market, import or distribute any Implementation.” Nevertheless, in March 2019, Luxembourg-based Sisvel Worldwide S.A. introduced two new patent swimming pools providing licenses on patents “related to the VP9 and AV1 specs.”

On April 8, 2019, AOM issued a press release that “AOM is conscious of the latest third-party announcement making an attempt to launch a joint patent licensing program for AV1.” The assertion discusses the steps AOM had taken to make sure that AV1 didn’t infringe on third-party rights however didn’t deny the infringement, which was affordable provided that the related patent checklist was not but accessible. In response to one trade observer, “All the premise of AV1’s basis as a totally royalty-free video codec has subsequently been thrown into doubt — which has stunned virtually nobody.” As of this date, the problem has not been resolved.

Compatibility

The web site CanIUse lists AV1 browser compatibility for each desktop and cellular at 74.9% as in comparison with H.264’s 98.23%, VP9’s 96.26%, and HEVC’s 18.07%. The one main browsers that lack AV1 assist are the Safari browsers on the Mac and iOS, that are two of the few browsers that assist HEVC, regardless of Apple being an AOM member. In response to playback outcomes right here and right here, AV1 ought to play again effectively inside the browser on most newer desktop and pocket book computer systems, so deployments received’t want to attend for {hardware} decoding as they could on cellular platforms and virtually definitely will on OTT.

AV1 is supported on the Android platform natively, and, as talked about, has nascent assist amongst Sensible TV distributors and different front room units. In response to a number of experiences (see right here, right here, and right here) Google required all Android TV-based units shipped after March 31, 2021 to assist the AV1 codec. Nonetheless, as in comparison with the put in base of front room units, which principally assist HEVC in addition to H.264 and VP9, the put in base of AV1-compatible front room units remains to be very small.

Efficiency

When gauging codec efficiency, you contemplate two points: (1) encoding complexity or velocity, and (2) encoding high quality. With most codecs, together with the 4 mentioned on this sequence, there’s an inverse relationship between the 2. That’s, the higher the encoding high quality, the longer it takes to encode. This interprets to increased encoding and transcoding prices. Since no codec can fully exchange H.264 at this level, these encoding or transcoding prices are additive to current H.264 encoding-related prices.

When first shipped, AV1 encoding occasions had been insanely lengthy, which restricted business use. Since then, AV1 encoding occasions have dropped considerably, although encoding prices stay excessive for a lot of cloud distributors (see right here and right here), presumably reflecting the encoding time wanted to output the codec.

AV1 high quality varies by the AV1 implementation. This assessment examined 4 implementations, AOM’s standalone aomenc encoder, Intel/Netflix’s SVT-AV1 codec, Visionular’s Aurora1 codec, and libaom, the AOM codec in FFmpeg. At finest, AV1 was about 24% extra environment friendly than x265, the HEVC codec in FFmpeg, and about 50% extra environment friendly than x264, the H.264 codec in FFmpeg. Since then, the Alliance for Open Media shaped a Working Group to advance the SVT-AV1 encoder “to create AV1 encoder implementations that ship glorious video compression throughout functions in ways in which take away computational complexity trade-offs for an ever-growing video supply market.”

As explored on this article, the excessive price of AV1 encoding, mixed with dropping costs for CDN supply, make AV1 a cheap selection just for movies with extraordinarily excessive view counts. For instance, whereas writing this text, I checked YouTube’s Trending movies. Within the ‘Now’ class, solely one of many high 5 movies had been encoding utilizing AV1, and that was the one music video within the group (Ruger – Bounce, then, 3.4 million views).

Within the ‘Films’ class, YouTube encoded 4 of the highest 5 trending motion pictures, all above 4.7 million views, with AV1. The lesson appears clear: even if you happen to’re YouTube, if a video doesn’t mission to high out over a number of million views, the elevated encoding price isn’t more likely to be recouped within the type of bandwidth financial savings.

Suitability

Now let’s study AV1’s suitability for a variety of particular encoding functions. AV1 is poorly fitted to dwell origination and transcode as a result of there are few, if any, {hardware} encoders for both perform. The identical is true for HTTP-based low-latency functions. Although a number of organizations have added real-time AV1 encoding to their WebRTC platforms, it’s not but an possibility in Wowza’s WebRTC implementation.

AV1 is properly fitted to very high-volume 4K movies for browser-based playback, although encoding price and playback efficiency must be thought-about. Notice that YouTube makes use of VP9 for many 4K movies, not AV1. As mentioned, {hardware} assist for AV1 playback in the lounge is nascent, and whereas AV1 can be utilized to ship HDR10+ metadata, AV1 just isn’t at present a supported codec for DolbyVision supply.

Royalty Standing

As talked about, a patent pool administrator named Sisvel launched a patent pool for AV1(and VP9) in March 2019 in search of royalties on client units, however not VP-encoded content material. On the WebM Mission FAQ referring to VP9, Google introduced that they’re conscious of the pool, however acknowledged that they’ve “no plans to restrict our use of VP9 or AV1 or change upcoming utilization plans primarily based on this announcement from Sisvel.” Since Sisvel isn’t at present in search of royalties on content material, the pool ought to have minimal affect on streaming producers contemplating publishing with the AV1 codec.

What You Have to Know to Produce AV1

AV1 has three profiles, Fundamental, Excessive, and Skilled. In response to AOM documentation, “[t]he Fundamental profile helps YUV 4:2:0 or monochrome bitstreams with bit depth equal to eight or 10. The Excessive profile additional provides assist for 4:4:4 bitstreams with the identical bit depth constraints. Lastly, the Skilled profile extends assist over the Excessive profile to additionally bitstreams with bit depth equal to 12, and likewise provides assist for the 4:2:2 video format.” There are additionally 14 ranges that outline playback capabilities from 426×240@ 30 fps to 7680×4320@120 kbps.

Curiously, Roku doesn’t establish the supported AV1 profile or stage for the Roku Extremely. Neither does Samsung, although their Kizen Sensible TV specs do outline supported AV1 resolutions and body charges for the varied fashions, which just about definitely pertains to the supported ranges. 

The overwhelming majority of AV1 encodes seem to make use of the Fundamental profile. For instance, the FFmpeg libaom AV1 Encoding Information doesn’t point out profiles, although you may set them with -profile change. In response to the FFmpeg documentation, AV1 “defaults to utilizing the profile which matches the bit depth and chroma subsampling of the enter.” So, if you happen to’re transcoding the everyday H.264 mezzanine file, FFmpeg ought to select the Fundamental profile mechanically.

Should you’re making an attempt to provide HDR10+ HDR output with AV1, it’s possible you’ll have to manually set the profile and stage. In any other case, except you’re a {hardware} developer or are actually pushing the decision / body charge / colour depth / dynamic vary spectrum, you most likely don’t want to fret about AV1 profiles and ranges.

Presets and Pace Controls

Like most codecs, all AV1 codecs have a profile or comparable setting that allows you to select the optimum mix of encoding time and output high quality in your AV1 encodes. This text discusses the varied presets utilized by the 4 AV1 codecs examined and may present helpful perception into what the presets do and the way they work.

Nowadays, nevertheless, you’ll have to make use of a non-Wowza expertise to distribute your AV1 encoded streams, since neither Wowza Streaming Engine or Wowza Streaming Cloud helps AV1 for both enter or output.

In our subsequent and ultimate article, we focus on Versatile Video Coding, or VVC.

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Extra Assets:

• The Streaming Codec Panorama in 2021
• Video Codecs and Encoding: Every part You Ought to Know
• VP9 Codec: Google’s Open-Supply Expertise Defined

About Jan Ozer

Jan Ozer is a number one professional on H.264, H.265, VP9, and AV1 encoding for dwell and on-demand manufacturing. Jan develops coaching programs for streaming media professionals, gives testing companies to encoder builders, and helps video producers excellent their encoding ladders… View extra