Eagerly awaited across the tech industry, this week the Alliance for Open Media (AOMedia) has published the first complete version of the bitstream and decoding process specification for their royalty-free AV1 video codec. The release of the AV1 1.0 spec will enable backers of AOMedia to add support for the technology to their products or services, including taking the all-important step of finalizing the designs for the low-power hardware decoders critical for driving the codec's adoption. At least initially, AV1 will be used primarily for streaming video and user-generated content as an alternative to HEVC and its ongoing royalty disputes, but eventually adoption of AV1 may expand to other applications.

The AV1 open-source video codec was developed with 4K+ ultra-high-def resolutions, HDR, and wide color gamut in mind. Among the key features the new codec, AOMedia mentions a 30% more efficient compression algorithm compared to existing methods, predictable requirements for computational capabilities of hardware, and maximum flexibility and scalability. The backers of the AV1 want the codec to be ubiquitous across devices and platforms, therefore expect it to be supported not only by major chipmakers, software designers, and service providers, but also by leading makers of consumer electronics.

AOMedia does not disclose key technological peculiarities of the AV1 video codec in a short whitepaper form, meanwhile parsing through a 600-page bitstream and decoding spec for developers does not necessarily help to explain all the peculiarities of the tech in general. Therefore, I am going to limit technical details about the AV1 to a necessary minimum here.

On a high level, the AV1 is conceptually similar to existing codecs, such as H.264 or H.265. AV1 uses the same basic elements as various codecs have used for well over a decade: block-based coding, variable block sizes (up to 128x128 pixels), block motion compensation, intra-frame compression, forward-integer transform and so on. Meanwhile, since we are talking about compression algorithms more efficient than existing ones, it is natural that the AV1 has a number of advantages over contemporary codecs.

The AV1 performs internal processing in 8, 10 or 12 bits per sample precision, it also supports all three widespread types of chroma subsampling (4:2:0, 4:2:2, 4:4:4), and virtually all major color gamuts and formats (sRGB, BT.2020 (both 10-bit and 12-bit), BT.2100, etc.). The BT.2020 and the BT.2100 recommendations include support not only for 3840×2160, but also for 7680×4320 (8K) resolution, so the AV1 is technically ready for the next-gen monitors and TVs.

AV1 Profiles
seq_profile Bit Depth sRGB Gamut Support Chroma Subsampling
0 8 or 10 No YUV 4:2:0
1 8 or 10 Yes YUV 4:4:4
2 8 or 10 No YUV 4:2:2
2 12 Yes YUV 4:2:0
YUV 4:2:2
YUV 4:4:4

Speaking of displays, it is necessary to note that the AV1 was designed to be compatible with existing interconnections, such as DisplayPort, eDP, HDMI and so on. That said, the technology should also be compatible with contemporary content protection technologies.

The publication of the AV1 spec 1.0 is merely the first step towards adoption of the technology by the market. AOMedia expects content creation tools and desktop browsers to begin to roll out support for AV1 later this year. To ensure this, AOMedia released an unoptimized/experimental AV1 software decoder and encoder for use in software applications. Then, sometimes in 2019, the consortium anticipates select chips and programs to support the tech. More widespread support of the AV1 along with adoption by software is projected for 2020.

Speaking of adoption, the list of AOMedia members includes a variety of influential companies, including Apple, Amazon, AMD, Arm, Broadcom, Facebook, Google, Hulu, Intel, IBM, Microsoft, Netflix, NVIDIA, Realtek, Sigma and many others. These companies either control huge ecosystems themselves, or develop chips that are used by hundreds of millions of customers worldwide. Their support will ensure widespread adoption of the AV1 in the next decade. In the meantime, AOMedia has already started R&D for the AV2, which is to succeed the AV1 codec.

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Source: AOMedia



View All Comments

  • tuxRoller - Saturday, March 31, 2018 - link

    Other than what others have mentioned, I'm not sure what you're saying.
    It's your main concern that the org isn't interested in itu status, and thus, uncertain ott?
  • GreenReaper - Sunday, April 1, 2018 - link

    They managed to get VP9 into PC hardware - I'm sure they can manage AV1 more generally. Reply
  • npz - Friday, March 30, 2018 - link

    I will wait until the some effective implementations arrive. They had the same intentions with VP8, then VP9, and still did not succeed. I hope they do this time, but am not holding my breath.

    I also hope that both software and hardware implementations actually support all profiles. That was not the case with H.264 and is still not the case with H.265, which is disappointing. Imagine encoding your MP3 in certain ways and finding out that your portable player can't support VBR or that your phone won't support joint stereo. That's how it feels like with these implementations--free or proprietary on decode side.
  • saratoga4 - Friday, March 30, 2018 - link

    >I will wait until the some effective implementations arrive. They had the same intentions with VP8, then VP9, and still did not succeed.

    VP9 was very successful. The VPx codecs went from nothing to being used by the biggest content sites (Youtube, Netflix, etc). The speed at which VP9 was adopted is why everyone is onboard with AV1 (which is a rebrand of VP10).
  • npz - Friday, March 30, 2018 - link

    VP9 is absolutely not succesful. Just because youtube offers it means nothing. The ONLY times it's used is on desktop browser in linux or other *nix platforms. Otherwise, you'll be using the h.264 stream because that's the choice for built-in OS support and hardware acceleration across a variety of devices. I bet you if Google made stats available of when h.264 is used vs VP9 you'll see it overwhelmingly in favor of h.264. And you can absolutely forget about VP9 in the professional content creation space.

    AV1 is supposed to compete with h.265 yet I don't see an incentive yet, despite it being royality free. If AV1 started at the same time as h.265 several years ago I could see AV1 taking off, but since h.265 has already been established it has the economic network effect in its favor. Everyone has already invested into it especially on the professional side for content editing and creation both software and hardware (and already the superior encoder x265, in FOSS ironically) and there isn't even a good implementation of AV1 yet.

    I'll actually consider something successful when I see usage stats and actual broad implemenation
  • npz - Friday, March 30, 2018 - link

    furthermore what limits VP9 usage even further is that Google pairs the VP9 video with OPUS audio in their webm stream and while a limited set of devices (mostly discrete gpus, very few embeded devices and SoCs) offer limited VP9 decode (like I mentioned above not all profiles) they absolutely do not offer h/w OPUS decode and so the selection will still go to the h264+aac stream.

    And even when devices offer limited VP9 decode you can forget about encode.
  • npz - Friday, March 30, 2018 - link

    edit: actually by discrete gpus I meant Intel, nvidia, amd, not necessarily discrete, to distinguish between the big 3 and mobile, soc or dedicated professional devices Reply
  • eSyr - Friday, March 30, 2018 - link

    So, you meant virtually all desktop GPUs, qualcomm since 820, exynos since 7420, and mediatek since x20? And, for encoding, it's available in virtually every GPU and SoC released in the last 2 years. Reply
  • npz - Friday, March 30, 2018 - link

    Show me where can I use VP9 to record with on.my qualcom LG and Samsing phones. Show me the support page of smart TVs and roku like devices for playing back VP9 content. Reply
  • npz - Friday, March 30, 2018 - link

    As well as OPUS btw since both are required for the webm stream to be chosen over the mp4 dash stream Reply

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