> Reread my original post carefully - my point is that if you're stuck with 1080p as the maximum resolution, than the quality you can get with the revised ladder is strictly worse, because Netflix will want to jump up to UHD resolutions, but your device won't support it.
These are for their HEVC encodes. Apple (and most others) require H264 to have a separate ladder which will be 1080p limited and will be generated on different encode set and maximum video quality.* Almost any HEVC capable device can go to 4k, even if the screen is only 1080p. It will be used than down scaled.
> (And even assuming that the UHD will be better based on this chart is kind of a leap, because it depends on what artifacts you're most sensitive to. Objective metrics ≠ subjective experience. In several of their comparisons, I prefer the lower res version because the new one is simply too artifacted.)
Certainly objective and subjective metrics have differences, but VMAF does correlate pretty tightly with subjective metrics. This is a very detailed subject, I summed up many of my thoughts on the differences in my demuxed talk last year here: https://www.youtube.com/watch?v=nCUsXhSPyyw
Really? I wasn't aware Netflix even offered anything other than H.264 at <= 1080p. I know Youtube doesn't. If this is all HEVC maybe you're right and the resolution issue isn't such a big deal. If this is actually the case I wish they would have said so explicitly in the blog post.
> VMAF does correlate pretty tightly with subjective metrics. This is a very detailed subject, I summed up many of my thoughts on the differences in my demuxed talk last year here: https://www.youtube.com/watch?v=nCUsXhSPyyw
Thanks, I'll check that out when I have the time. I'd still emphasize that it's quite possible for objective metrics to be fooled (that's why codecs have psy tunings!), and I do prefer several "old-ladder" images over the newer versions in Netflix comparisons here. I suppose I've become rather cynical about claims made on the basis of metrics ("now 50% less bitrate for the same quality!"), when to my eye, web video has always been very bad and is getting worse as companies keep reducing the bitrate.
Youtube offers various codecs, also including VP8 at all resolution/framerate settings H.264 is offered on (not all formats will always be available). For example, here's the youtube-dl format list for a well-known video:
[youtube] dQw4w9WgXcQ: Downloading webpage
[info] Available formats for dQw4w9WgXcQ:
format code extension resolution note
249 webm audio only tiny 49k , opus @ 50k (48000Hz), 1.18MiB
250 webm audio only tiny 65k , opus @ 70k (48000Hz), 1.55MiB
140 m4a audio only tiny 130k , m4a_dash container, mp4a.40.2@128k (44100Hz), 3.27MiB
251 webm audio only tiny 136k , opus @160k (48000Hz), 3.28MiB
394 mp4 256x144 144p 73k , av01.0.00M.08, 25fps, video only, 1.72MiB
278 webm 256x144 144p 97k , webm container, vp9, 25fps, video only, 2.25MiB
160 mp4 256x144 144p 107k , avc1.4d400c, 25fps, video only, 2.05MiB
395 mp4 426x240 240p 159k , av01.0.00M.08, 25fps, video only, 3.42MiB
242 webm 426x240 240p 217k , vp9, 25fps, video only, 4.04MiB
133 mp4 426x240 240p 290k , avc1.4d4015, 25fps, video only, 4.48MiB
396 mp4 640x360 360p 340k , av01.0.01M.08, 25fps, video only, 6.68MiB
243 webm 640x360 360p 396k , vp9, 25fps, video only, 6.96MiB
134 mp4 640x360 360p 484k , avc1.4d401e, 25fps, video only, 8.27MiB
244 webm 854x480 480p 586k , vp9, 25fps, video only, 10.03MiB
397 mp4 854x480 480p 603k , av01.0.04M.08, 25fps, video only, 11.37MiB
135 mp4 854x480 480p 741k , avc1.4d401e, 25fps, video only, 11.56MiB
247 webm 1280x720 720p 1035k , vp9, 25fps, video only, 17.67MiB
136 mp4 1280x720 720p 1077k , avc1.4d401f, 25fps, video only, 16.72MiB
398 mp4 1280x720 720p 1133k , av01.0.05M.08, 25fps, video only, 22.07MiB
399 mp4 1920x1080 1080p 2106k , av01.0.08M.08, 25fps, video only, 40.74MiB
248 webm 1920x1080 1080p 2666k , vp9, 25fps, video only, 58.46MiB
137 mp4 1920x1080 1080p 4640k , avc1.640028, 25fps, video only, 78.96MiB
18 mp4 640x360 360p 601k , avc1.42001E, 25fps, mp4a.40.2@ 96k (44100Hz), 15.19MiB (best)
Netflix has a debug screen that will show you the codec info. It varies depending on platform but you can Google it to find the one for your platform. For the Windows app, it's Ctrl-Alt-Shift-D. That shows H264 on my device since I don't have hardware that can decode H265. On Android, I've seen VP9 streams.
These are for their HEVC encodes. Apple (and most others) require H264 to have a separate ladder which will be 1080p limited and will be generated on different encode set and maximum video quality.* Almost any HEVC capable device can go to 4k, even if the screen is only 1080p. It will be used than down scaled.
> (And even assuming that the UHD will be better based on this chart is kind of a leap, because it depends on what artifacts you're most sensitive to. Objective metrics ≠ subjective experience. In several of their comparisons, I prefer the lower res version because the new one is simply too artifacted.)
Certainly objective and subjective metrics have differences, but VMAF does correlate pretty tightly with subjective metrics. This is a very detailed subject, I summed up many of my thoughts on the differences in my demuxed talk last year here: https://www.youtube.com/watch?v=nCUsXhSPyyw
* https://developer.apple.com/documentation/http_live_streamin... 1.23 iirc