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It seems funny, but this year’s Apple’s WWDC was one of the most import yet, but not due to something said during the 2017’s Keynote. Instead, this low profile presentation will have far reaching implications over the next 8 to 10 years on the video delivery industry, from Google to Netflix. As Apple decided to use H.265 and WebVTT, the whole industry will be forced to follow suit.
The story started back in May 2010 when Google acquired On2 technologies, and specifically all the related IP to the VP8 video codec. Google was not happy with having to rely on an open source but patented video codecs for it’s future plans, and thought that VP8 would be a solution for that problem. VP8 was still a patented technology, although Google vowed never to use those patents as a weapon against users of VP8 encoders or decoders. However, Google actually tried to force it on the industry, announcing that it would support only VP8 on Google Chrome. Fortunately for everyone, this threat never materialised. This was due to a number of factors such as:
- VP8’s lack of performance against H.264
- Virtually non existing hardware decoding support
Eventually, Google caved in, and continued to support H.264, which is the de facto standard codec on both web and broadcast world. In the meantime, a number of codecs were rendered obsolete including VC-1, VP8 and MPEG-2.
Fast forward to 2017
Challenges om 2017 are fairly different. Now the industry’s buzzwords are UltraHD, Wide Colour Gamut, HDR and HFR, which means a new codec is needed to handle them all. This time, two alternatives came into consideration: MPEG Group H.265 (AKA HEVC) and Google’s VP9, both corresponding to evolutions to the corresponding previous version (H.264 and VP8, correspondingly).
So, a new codec war was envisioned. However, this time players moved significantly faster and before. Most silicon manufacturers were quite quick to react:
- Broadcom deployed H.265 supporting chipset to STBs in 2015 (did one of those myself in 2015 🙂 )
- Marvel’s Armada 1500, Rockchip’s RK3288 and AmLogic’s S812, all of those announced between 2015 and 2016.
Most of those offerings did not supported VP9 at time of launch, and then, most won’t support it though a microcode update. This creates a significant legacy installed base, for which VP9 is not an option.
On the mobile side, things weren’t that different. Qualcomm announced the Snapdragon 805 processor back in 2014, supporting 4K H.265 decoding, and encoding shortly afterwards. Even today, Qualcomm only supports VP9 decoding and encoding on the flagship Snapdragon 835 processor, leaving all other processors with software decoding as an option. On the encoding side, there’s not option at all. All current smartphones are limited to [email protected] as defined on the H.264 L5.1 profile, and even then, at a very high bandwidth, in excess of 50 mbps.
On the Samsung side, things aren’t that different: all Exynos processors since Exynos 7 support H.265 decoding, and only the latest chip, the Exynos 9 supports VP9.
The reason why VP9 hardware support is lacking is fairly easy to explain, and can be demonstrated by this screenshot coming from the VP9 specification’s page:
Contrary to H.265, whose format was finalised back in 2013, which first implementations in 2015, VP9 bitstream is still not final, making silicon vendors to take educated guests in order to support it on hardware, including using programmable components, making such silicon more expensive that the H.265 counterparts.
As a side effect of being ready sooner, H.265 now supports more features, such as native 3D support and scalable versions, allowing currently deployed hardware to be compatible with the base streams even if the new advanced features aren’t supported. Why is this important ? Bandwidth. Let’s take as an example a Satellite broadcaster such as Dish (yeah, I know satellite broadcasters are a dying breed, but they still account for more subscribers than IPTV…). It will be possible for such broadcasters to reuse the already broadcasting HD or 4K stream, and add an additional stream for the multi view 3D format, thus saving a significant amount of bandwidth (around 30% from the 30-40Mbps of an 3D 4K channel) and at the same time, being compatible with the already deployed set top boxes.