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by zbobet2012 2585 days ago
Netflix and other (similar) streaming services which user per-title encoding technologies deliver a harmonic mean PSNR of greater than 45 and greater than 94 VMAF on their highest rendition, which most well connected users pull. This is visually indistinguishable from a lossless encode.

Complaining about the _size_ or _bitrate_ of encoded file isn't worthwhile. Encoding technology has advanced substantially since blue-ray days and we simply no longer needs the 40mbps bitrate.

Indeed HEVC can offer a mathematically lossless encode at around 90mbps for most content.

2 comments

I'm sure you're very knowledgeable and correct about a lot of things, but where your argumentation falls down most is user experience.

A concrete example: You say here that what Netflix provides is "visually indistinguishable from a lossless encode". Try actually doing this with an open mind and then make this claim again. It was definitely not the case when I last tried it (very recently).

Argumentation of this nature is sort of endemic in the tech industry: "You think you see or experience this, but I know what you see and experience and you are wrong". It happens in discussions about battery life, visual appeal of different encoding options, basically anything which is at some point subjective and while the people claiming to see a difference could be (factually) wrong in a lot of cases (I often cannot tell), it is very arrogant to sit/stand there and tell them that you know better than them what they see.

But what about when it has been tested and proven that people cannot discern the difference? I don't know if this is what was done with the per-title encoding that the parent comment was referring to, but I know it is the situation with audio. So many audiophiles swear they can hear a difference between FLAC and high quality VBR MP3, but it has been repeatedly demonstrated that, when presented with both, humans cannot distinguish them better than chance.
> But what about when it has been tested and proven that people cannot discern the difference?

The way people perceive (and how to measure it) is in fact not a solved problem. There are studies done and we can often say with a high degree of certainty that something is probably not visible/distinguishable, but claiming something like that for everyone is too strong and also misrepresenting the state of our learning.

Huh? Open Netflix and play any recently added 1080p stream that contains dark scenes. Those scenes are literally unwatchable. I don't mean "not perfect". I mean they look like they were encoded with a 256 color palette. Bitrate is what matters–even with current codecs used by streaming services–and they do not provide something watchable.