Is it just me or does the author here sound like they're hating just to hate? The writing doesn't sound that terrible. Maybe it's a bit amateur but isn't that what you're expect from an engineering blog post written by people whose day job is to write code. And for a layman, the image comparison isn't as bad as they make it out to seem.
Video encoding requires using your eyes
11–20 of 53 posts
Re: Video encoding requires using your eyes
#12I'd imagine that for the group of people who can see the difference, it must be very aggravating - much like when you start to see kerning mistakes. For the rest of us, though, it is imperceptible.
Re: Video encoding requires using your eyes
#13I don't see (or maybe don't recognize) any issues with the image that they're talking about (ringing, color shift, or fake details). It most certainly doesn't look awful to me, it looks exactly the same, only a bit sharper.
You can see some ringing in the sky around the trees and on the line between the crow's beak/feathers if you look closely. (Alvin's?) fur goes much farther down his forehead as well. People who work deeply with codecs are usually hypersensitive to these sorts of issues that mere mortals like us need to try to see. There used to be a legendary blog called "Diaries of an x264 developer" by Fiona Glaser [0] where she'd…
I agree the "negative" artifacts are almost impossible to see, and came here to the comments to see what the heck the author was talking about.
> People who work deeply with codecs are usually hypersensitive to these sorts of issues that mere mortals like us need to try to see.
I think that kind of shows that the author is unfairly critical.
They're saying "this should not have shipped", when it seems just fine to us "mere mortals".
Yes, video encoding requires using your eyes. But it also seems like it should use normal eyes, not hypersensitive eyes...?
Re: Video encoding requires using your eyes
#14Is downscaling difficult? I can understand that upscaling is hard and you need learning. But when downscaling, for me OpenCV's "area" interpolation always gives great results super fast.
Re: Video encoding requires using your eyes
#15Is downscaling difficult? I can understand that upscaling is hard and you need learning. But when downscaling, for me OpenCV's "area" interpolation always gives great results super fast.
Is “area” just a box filter, which is what it sounds like? If so, it gives really blurry results; hardly great.
Re: Video encoding requires using your eyes
#16I love bagging on lazy engineers who just chuck code over the fence without caring about the user experience, but I seriously doubt I would notice this. The sad truth is a lot of video is watched in the background and Netflix knows this. For the specific case of a children's cartoon, I doubt the children watching will notice or care.
If there is user feedback about the quality, then by all means listen to users and at least have an "advanced settings" menu in the app to let users toggle between encoders if they really care.
Re: Video encoding requires using your eyes
#17> Is Lanczos an example, or the current best option
What’s the best (computationally not that more expensive than Lanczos) option?
Edit: also some CV researchers write like that (the Netflix writing) — bicubic is like a flag in opencv that they just use. Probably those researchers were much more preoccupied with the researchy problem than actual wide deployment, which is what many researchers do
Re: Video encoding requires using your eyes
#18Is downscaling difficult? I can understand that upscaling is hard and you need learning. But when downscaling, for me OpenCV's "area" interpolation always gives great results super fast.
Is “area” just a box filter, which is what it sounds like? If so, it gives really blurry results; hardly great.
Yes, it can be seen as a box filter (with the size equal to the stride length) on the nearest-neighbor upscaled image. Basically if you imagine overlaying the new square grid over the old one and then each new pixel gets a weighted combination of the overlapping old pixel squares, weighted by the overlap areas.
To my eyes it's more pleasant than Lanczos, which has too much ringing.
Re: Video encoding requires using your eyes
#19I love bagging on lazy engineers who just chuck code over the fence without caring about the user experience, but I seriously doubt I would notice this. The sad truth is a lot of video is watched in the background and Netflix knows this. For the specific case of a children's cartoon, I doubt the children watching will notice or care. If there is user feedback about the quality, then by all means listen to users and a…
When will people finally learn that people do not know what they want. You, the expert has to know what works and how and whats the best way to use it properly.
And do not rely on user feedback. Again. People don't know whats wrong, they don't even know what's right. They just feel that something is off. And only a very small percentage of users would write an email and even fewer would get through the automated AI bullshit or the snotty person who would dare to hand you a HOW TO USE NETFLIX pdf when you want to report something.
Re: Video encoding requires using your eyes
#20I don't see (or maybe don't recognize) any issues with the image that they're talking about (ringing, color shift, or fake details). It most certainly doesn't look awful to me, it looks exactly the same, only a bit sharper.
You can see some ringing in the sky around the trees and on the line between the crow's beak/feathers if you look closely. (Alvin's?) fur goes much farther down his forehead as well. People who work deeply with codecs are usually hypersensitive to these sorts of issues that mere mortals like us need to try to see. There used to be a legendary blog called "Diaries of an x264 developer" by Fiona Glaser [0] where she'd…
The color shift was the most obvious to me. The other artifacts may not be super visible, but if you care about preserving the original picture, it’s certainly an important quality difference.