The Evolution of Video Codecs: AV1 and HEVC Take the Lead

HEVC and AV1 - The Evolution of Codecs

For years, H.264 has remained dominant because it plays everywhere; but as videos grow larger, faster, and deeper in color, cost of distributing H.264 has become too high.

AV1 has leap-frogged VP9 in the so-called “open-source” horse race, while HEVC is the clear successor to H.264 in standards-based codecs, at least for the next 3-4 years as VVC slowly matures.

AV1 and HEVC have had their well-known Achilles heels, AV1 in the living room and on Apple devices, and HEVC in browsers. The last few months have seen critical movement and new data in all these platforms that will fundamentally change how we use them.

AV1 in the Living Room

HEVC has dominated Smart TVs and OTT dongles since 4K and High Dynamic Range (HDR) became must-haves for premium content producers. However, in late 2021, Netflix began distributing AV1 video to this market, and device support has burgeoned since then. As Bitmovin reported in this blog post, AV1 runs on smart TVs running Android TV and Google TV operating systems, including Sony Google TV models from 2021 and forward and many Amazon Fire TV models as far back as 2020. Starting in late 2020, most Samsung TVs have hardware AV1 decoders, with LG extending support to some TVs.

HEVC and AV1 - The Evolution of Codecs
Figure 1. Netflix started the migration of living room content towards AV1. 

Regarding OTT dongles, the Amazon Fire TV Stick 4K Max and the Roku Streaming Stick 4K, and other Roku models support AV1 playback, as does the PlayStation 4 Pro and Xbox One.

The one caveat is that AV1 support for dynamic metadata is nascent. The HDR10+ AV1 Metadata Handling Specification was finalized on December 7, 2022, so it will take a while for encoders and decoders to fully and reliably support it. Since Google’s Project Caviar is proposing a royalty-free alternative to Dolby Vision, Dolby Vision still only supports H.264 and HEVC and may never support AV1.

To be clear, YouTube supports HDR with AV1, so it’s technically feasible today. But standards like the HDR10+ Metadata Handling Specification promote broad playback compatibility necessary for most publishers to help it. For example, when Netflix first started streaming video to bright TV sets in 2021, it was Standard Dynamic Range only, and that’s still the case. Besides, suppose you’re already encoding your video to HEVC for living room delivery in HDR. In that case, it may not make economic sense to reencode to AV1 for slightly more efficient delivery to a market that you’re already serving.

Play Video about HEVC and AV1 - The Evolution of Codecs - thumbnail
Watch the full conversation on YouTube:

HEVC Plays in Chrome

Browser playback has been a traditional strength of AV1 since it first launched. Not surprising, given that all major browser developers are members of the Alliance for Open Media. For the same reason, it’s also no surprise that browsers like Chrome and Firefox never supported HEVC, even when hardware or software on the computer or device did support HEVC playback.

This changed in September 2022, when Google “fixed a bug” and enabled HEVC support when the hardware HEVC playback was available on the system. As the story goes, the lack of HEVC playback was reported by Bitmovin as a bug in 2015. On September 19, 2022, Google responded six years later, “Enabled by default on all releases.” Within weeks, browser support for HEVC, as reported in CanIUse, jumped from the low 20s to 86.49, well ahead of AV1 at around 73%.

This could be a massive benefit to streaming sites that deliver primarily to computers and mobile devices and have avoided HEVC because of the lack of Chrome playback. In a straightforward bugfix, Google enabled HEVC playback on all supported platforms with existing decoders, including Windows, Mac, iOS, and Android.

A caveat exists here, as well, specifically that “HEVC with Widevine DRM is not supported at this point.” This obviously limits the benefit of Chrome support for premium content producers.

Apple May Start Supporting AV1

Apple has a checkered history with the Alliance for Open Media. When Apple joined in 2018, they big footed their way in as a “founding member,” even though the organization was formed over two years earlier. Despite this aggressive posturing, Apple has never supported AV1 playback in its operating systems or browsers and was a massive supporter of HEVC.

Figure 2. Apple is now supporting AV1 playback in Safari 16.4.

At least respecting AV1, this may be about to change. With Safari 16.4, Apple added AV1 support in the media capabilities API and WebRTC support for hardware AV1 decoding on supported device configurations. It turns out that the software AV1 decoder dav1d is already included in the updated WebKit engine used in Apple Safari Technology Preview 161.

Apple is dipping its toes in the AV1 waters; this could mean that it intends to support AV1 playback via software in the short term or that it may unlock previously unannounced hardware playback capabilities in existing CPUs. It could also mean hardware AV1 support will be added in future CPUs. Whatever the strategy, it’s probably safe to assume that Safari will play AV1 at some point in the future, hopefully sooner than later.

That said, the major data point that recently surfaced was a Scientamobile report that indicated that while 86.60% of HEVC smartphones had HEVC hardware support, only 2.52% had AV1 support. Since hardware support guarantees full frame rate playback at minimal power draw, HEVC will likely remain the format of choice for mobile devices for the next 12-24 months.

Figure 3. HEVC currently enjoys much greater hardware support in mobile devices than AV1.

Whether you decide to stay with H.264 for your live transcodes, or transition to AV1 or HEVC, NETINT has you covered. Our G4-based line of products (T408, T432) transcode to H.264 and HEVC, while the G5-based Quadra line (T1, T1A, T2A) support H.264, HEVC, and AV1. All products deliver competitive video quality, market-leading density, a highly affordable cost per stream, and the lowest possible power consumption and OPEX.