On Tuesday, May 16, 2017, at Streaming Media East, I’m presenting a talk entitled How To: Comparing and Choosing The Best HEVC Codec. Unfortunately, I could only get two codec vendors to participate, x265 and MainConcept. It’s not for lack of trying; I also asked Elemental, Beamr/Vanguard, and Fraunhofer if they’d like to participate and all declined, as did Intel, Ittiam, and NTT.
To add some context to the analysis, I included VP9 and H.264 encodes. Then Bitmovin announced their live AV1 demonstration at NAB, so I asked them to participate and send comparison clips encoded with their compiled version of the AV1 codec, or Bitmovin AV1. They have, and I’ll be sharing the results during the session.
In addition to the PSNR comparisons I’ve used in the past, I’ll also be sharing some comparisons using the Netflix VMAF metric as computed by cloud encoding vendor Hybrik. This is the quality metric that Netflix relies upon to assist in their encoding process, and it’s exciting to finally check it out.
Just to let you know, the AV1 comparisons likely will be PSNR/MS SSIM only due to logistical issues. But the x265/VP9/MainConcept/H.264 results will be graded by VMAF in addition to PSNR. As you can see in the figure, at least in this configuration (1080p encodes for Netflix’s Meridian clip), Bitmovin AV1 performed very well. I’m in the process of checking all my work, so this slide is preliminary, but the results were impressive in many cases (still haven’t seen the 4K comparisons). There are also lots of caveats about encoding time and the like that I’ll share at the session.
To make sure that I optimized all encodes, I set the basic parameters and MainConcept prepared presets for their encodes, and MulticoreWare prepared presets for x265. I prepared the presets for VP9 with guidance from Google (they reviewed the VP9 chapter of my latest book, where I created the encoding recommendations). I performed all these encodes in my office, keeping my trusty HP Z840 running nights and weekends for awhile. Bitmovin created the presets and performed all Bitmovin AV1 encodes in their cloud facility; I decoded and tested the quality in my office.
Between Bitmovin AV1 and VMAF, I know we’ll have some interesting data to share. I want to thank all the companies that assisted along the way, including Bitmovin, Google, HP, Hybrik, MainConcept, MulticoreWare, and Netflix.