The H.265/HEVC state of play
Thursday, 01 June 2017
Apple seem pretty quiet when it comes to blessing the H.265 codec. It is a codec dedicated to better quality for large raster video at lower bandwidths. These kind of codecs are needed for 4K broadcast and streaming, and are useful for 360º/VR video distribution.
Like DV, HDV and H.264, new codecs are designed to be efficient using hardware that is expected to be commonly available a few years after launch.
That means that H.265 (aka HEVC or ‘High Efficiency Video Coding’) algorithms expect to access the kind of power that isn't mainstream yet. Although today’s commonly available hardware can decode H.265 quickly, encoding is more of a problem. This is especially true of Apple’s currently anaemic Mac hardware.
Another reason is that patents and algorithms mean that the best way of encoding 4K, 6K and 8K video streams hasn't yet been settled on by the industry.
The state of High Efficiency Video Coding codecs has been summarised by Jan Ozer of Streaming Learning Center. A PDF of the presentation he gave at Streaming Media East in May describes the state of play comparing different HEVC implementations, VP9 and Bitmovin AV1.
His conclusions include:
- Particularly at lower bitrates, x265, Main Concept (H.265) and VP9 deliver substantially better performance than H.264
- Both HEVC codecs and VP9 produce very similar performance
- Choice between x265 and Main Concept (H.265) should be based on factors other than quality
- AV1 Encoding times are still very inefficient
- AV1 is at least as good as HEVC now, and will likely be quite a lot better when specification has been fully decided on - it is still in development
Find out more on Jan’s blog.
The bottom line? Here is Jan commenting on some feedback to a post of his at Streaming Media:
HEVC will do well in broadcast, no doubt. Still not available in any browser, iOS, and Netflix prefers VP9/AV1 over HEVC for Android. VP9 gets you most browsers and many smart TVs and OTT boxes (like Roku 4), so it's the smart money UHD codec if you don't need HDR.