AV1 is the new and improved video compression codec on the block. Whether the sense of competition is real or just perceived between the AV1 and current video compression standard HEVC, the battle lines are being drawn. Can the two get along?
AV1, or AOMedia Video Codec 1.0, is an open-source royalty-free video codec that was developed by the Alliance for Open Media, which counts Amazon, Apple, Facebook, Google, Intel, Microsoft and Netflix among its founding members. The group’s promoting members include Adobe, Bitmovin, CableLabs and Hulu. In short, a lot of big companies support AV1. After years of development, AV1 officially debuted in late March.
“Nearly three years after launching AOMedia, the AV1 codec addresses real bottlenecks for unleashing the highest-quality video for the entire ecosystem, allowing for better viewing experiences across all screens and data networks,” said AOMedia Executive Director Gabe Frost in a statement. “By listening to the industry’s feedback in an open and collaborative manner and bringing together leading experts to develop AV1, an entire ecosystem can begin creating video products and experiences that customers love.”
AV1 could find itself now going up against HEVC. HEVC (H.265), or high efficiency video codec, was built by the International Telecommunication Union and the Moving Pictures Expert Group (MPEG). It was designed to better handle higher resolution video and can provide high-quality video at bitrates of about 50% less than H.264. Access to the HEVC codec is obtained through independent licensing administrator HEVC Advance.
Both codecs are built to handle 4K and other higher-bitrate video technologies, but HEVC has been in use for a while now and AV1 was just released. Before we pit them against each other, let’s get to know AV1 a little better.
AV1 101
AV1 is something of a successor to VP9, an open-source video compression codec developed by Google. AV1 promise 30% better compression than VP9, based on testing performed by Bitmovin. That means AV1 can deliver 4K UHD video content while using less data.
AOMedia built AV1 for both commercial and noncommercial use in internet applications and services including browsers, streaming and videoconferencing services, as well as hardware and software implementation. AV1 is defined by a bitstream specification, binding specifications for using the codec with different file formats and encryption, and an encoder and decoder reference code.
Frost said that throughout 2018, AV1 will gain support in all HTML5-based browsers and all major open-source tools like FFmpeg, and silicon IP will begin coming out in some of the smaller vendors. He said the HTML5 sockets will allow people to consume the content and the tools will allow companies to produce the content. Frost predicted that by 2020, AV1 will begin showing up broadly in mobile chipsets.
Consumers will most likely see the effects of AV1 in a few different ways, Frost said. First, it will be used for delivering more HD content to users on their current devices, particularly when they are connected to mobile networks with lower bandwidth. Second, it will impact the experience for real-time communication applications, again, particularly on mobile networks. Third, he said AV1 will improve time to first frame and reduce buffering.
“When you have less bits that you need to send down initially from when you hit play to when you actually see the video start to play, you can dramatically reduce that time when you have great compression efficiency,” Frost said.
Facebook said in recent tests that AV1 surpasses its stated goal of 30% better compression than VP9, and achieved gains of 50.3%, 46.2% and 34.0%, compared to x264 main profile, x264 high profile and libvpx-vp9, respectively. But it also said AV1 requires longer encoding times vs. current alternatives due to increased complexity.
“Our tests were conducted primarily with Standard Definition (SD) and High Definition (HD) video files, because those are currently the most popular video formats on Facebook. But because AV1's performance increased as video resolution increased, we conclude the new compression codec will likely deliver even higher efficiency gains with UHD/4K and 8K content,” Facebook Software Engineer Yu Liu wrote in a blog post.
During the NAB Show in Las Vegas, Matt Frost, head of strategy and partnerships for Google Chrome Media and founding board member of AOMedia, it’s too early to predict what the average stream size will be for AV1 videos, but he revealed that during the AV1 launch party, AOMedia members were able to show a 720p video on a Samsung mobile device and have it only use 207 kilobits.
AV1 vs. HEVC
Despite longer encode times, AV1 flashes a multitude of impressive compression stats that could make HEVC feel threatened. But Gabe Frost said that the HEVC codec doesn’t loom over AOMedia’s work with AV1.
“It’s natural to want to create war between this thing and that thing. I can say that we very rarely talk about HEVC in the work that we do,” Gabe Frost said.
He did however say that AOMedia was finding that the online video environment that had been created over the last five to 10 years had started to become unsuitable for companies hoping to have an impact with video product.
“We need to take advantage of the advances with silicon screens and connectivity to deliver great products and for video, that shows up in codecs. When we can’t get codecs deployed because there’s enough uncertainty in the space that it’s holding up adoption, you can’t get user engagement,” Gabe Frost said, adding that HEVC is part of that conversation due to the uncertainty around licensing the codec.
“We wanted to shift the focus from jamming a bunch of intellectual property into a codec to making the codec efficient and low-cost to the point where it can be royalty free,” said Gabe Frost. “We want companies to be able to compete with each other in building great products rather than in this underlying foundation.”
HEVC Advance CEO Peter Moller offered a somewhat more skeptical view of AV1. He said AV1 and HEVC can and will co-exist, just as AVC and VP9 co-exist today. He also said that with Google using its YouTube platform to promote AV1, and others in the streaming world that have voiced support, AV1 will undoubtedly provide a competing codec to HEVC in some use cases. But he questioned if AV1 could live up to its promises of improved performance and no royalties.
“The biggest question with AV1, of course, is whether the performance claims and promised improvements ever come to fruition. And whether such improvements will ever offset the cost and expense of companies implementing another codec alongside HEVC,” said Moller. “As well, the IP issues remain unknown. The stated promise of AV1 being a royalty free codec seems optimistic at best, and, as a result, it seems highly likely that companies that implement AV1 will be assuming a great deal of unknown IP risk.”
At NAB, when streaming media analyst Dan Rayburn asked Matt Frost about how AOMedia will convince content owners to switch to AV1 and change their workflows, he admitted it won’t be easy.
“It is a pain to switch to a new codec. It is costly to support multiple codecs. But having a codec that is 30% to 40% better is worth it,” Matt Frost said.
He also said that AOMedia has created a fund to help pay for the defense of any AV1 user or AOMedia member that is sued for patent infringement.
“We’ve taken every step possible to eliminate IP risk,” Matt Frost said, adding that it’s impossible to fully guarantee that patent litigation won’t pop up at some point.
As AV1 moves through the different phases of implementation and as some uncertainty continues to swirl around the new codec, HEVC will still have a place in the online video industry. But if AV1 can continue to prove true all its promises about considerably more efficient compression and steer clear of royalties and legal drama, it will be a strong competitor for HEVC.