Ashutosh Pandey, Technical Head, Network 18
Many companies are joining the Alliance for Open Media (AOM), which is working on the next-generation AV1 video compression standard. The alliance is targeting an improvement of 50 percent over VP9/HEVC with reasonable increase in encoding and playback complexity. One focus is UHD video, including higher bitrate, wider color gamut, and increased frame rates, with the group targeting the ability to play 4K 60 fps in a browser on a reasonably fast computer. The base version of the codec will support 10-bit and 12-bit encoding, as well as the BT.2020 color space. Another focus is providing a codec for WebRTC (real-time communications), an initiative supported by the alliance members – Google and Mozilla, and similar applications including Microsoft’s Skype.
AV1 is positioned to compete directly with HEVC in most major streaming-related markets, including browser-based streaming, mobile, OTT, smart TVs, and set-top boxes, which are the primary markets served by the alliance members. Precise positioning will not be known until the codec is released and tested and comparative quality and CPU playback requirements can be assessed.
AV1’s most distinct competitive advantage is that it is royalty free, while HEVC comes encumbered with known royalties on devices via the MPEG LA and HEVC advance patent pools.
There are a few reasons, companies chose to support AV1. There are limitations when it comes to UHD. YouTube only encodes UHD in VP9, a compression format that no other device or browser is capable of decoding. Moreover, Netflix has clearly stated that as soon as AV1 is available, it will initially support AV1 in browsers as it is paying HEVC royalties, and if it can reduce these costs by using a different codec, without impacting the QoE, that is a win-win situation. If one wants to have one’s own OTT service, and the devices only support AV1 and not HEVC, they will cut themselves from those devices. That is not a great way to enter the OTT market.
AV1 mythbusters. The performance mentioned by AOM sources as being 25–35 percent better than HEVC has to be verified by independent sources.
One important aspect when it comes to adopting a codec is the decoding device support. All of the popular OTT devices (i.e., smartphones, tablets, IP STBs, and TVs) have a hardware decoder. The AV1 decoder is much more complex than HEVC and will require new devices.
Universality of a codec is key. If the AV1 decoder BoM (decoding system plus royalties) is higher than the HEVC BoM, then it will be a non-starter.
Encoding costs are also important to consider. Today, the AV1 reference model is 100 times slower than an optimized HEVC encoder. AV1 has hit another bump here, because if the encoding cost is too high, broadcasters and service providers will stay in the AVC/HEVC world.
AV1 is only for ABR and does not support broadcast.
AV1 has taken extra precautions to make sure no patents are infringed. The legal construction of AOM uses an umbrella patent scheme, meaning the AOM licensors license their AV1-connected patents to anyone, anywhere, anytime based on reciprocity.
The big question is whether AV1 is a competitor to VP9 and HEVC, or the next generation? For very large OTT companies, it is a potential competitor. For most other sites, it is looking more and more like the next generation.
Is the AV1 announcement as big of a deal as its support of HEVC? I do not think so for several reasons. We do not know intentions, AV1 faces serious roadblocks and AV1’s impact will not be meaningful before 2020. Until then, there is room for enhancement of AVC.
I believe that technology developers deserve as much money as they can possibly make from their efforts. If you can charge it, and people pay it, you have earned it. The critical mistake HEVC IP owners made was assuming that they were the only game in town. HEVC usage among their customers dropped by 50 percent, from 6 percent to 3 percent. Meanwhile, open-source VP9, in many ways the predecessor to AV1, debuted at 11 percent. It seldom makes sense to raise the cost of a product experiencing dramatic loss of market share. It is tough to say how the HEVC versus AV1 battle will turn out.