Adventures with ffmpeg and color ranges • Hacker News Board

Re: Adventures with ffmpeg and color ranges

#91

Post by saurik » Wed, May 29, 2019, 10:05 PM UTC

shawabawa3 wrote: post #78

saurik wrote: post #56

Earlier quoted context omitted.

Not only does the full URL not show in my browser (Safari), the full URL doesn't even show on this forum (for me it is cut off after "content"). When you receive a URL via chat or on social networks, it is in the form of a preview and might not even show the domain name. The user also isn't typing these URLs in, with or without human readable text in the path. Essentially all of the arguments for making URLs more bri…

> Essentially all of the arguments for making URLs more brittle (which is what you are doing by adding human readable text) Not if done right, like e.g. stack overflow, see https://stackoverflow.com/questions/517355/string-formatting... The human readable text is actually meaningless, and anything after the id will redirect there, e.g. https://stackoverflow.com/questions/517355/this-could-be-any...

This technique (which I almost commented on in my original comment, but didn't) is brittle in a different way (making it so that attempts to search for the URL have no well-known canonical representation), and quite simply totally undermines the entire argument being made (which is why I didn't comment on it) that someone can use the slug of a URL to decide whether or not they want to click on the content: you can change the URL to say anything you want. At this point, there is no value in bothering with having done this: it is just extra text in the URL for no concrete benefit.

meta.stackexchange.com/questions/148454/why-does-stack-overflow-use-title-slugs/

Re: Adventures with ffmpeg and color ranges

#92

Post by bscphil » Thu, May 30, 2019, 12:33 AM UTC

jacobush wrote: post #57

bscphil wrote: post #40

Earlier quoted context omitted.

This is correct. In fact, the following statement from the post is nonsense: > For arcane reasons related to TV broadcast limitations, many video formats restrict the YUV color components to be in the 16..235 or 16..240 range instead of the full 0..255 range. Losing 14% of the already-barely-enough 8 bit dynamic range is bad enough, but it also often results in the black range starting at a quite visible grey value b…

Wow! Talladega nights was the first movie I saw on a Bluray setup. (PS3 at a friends.) I was shocked at how badly mastered it was. It sounds exactly like that problem. Everything was washed out.

Yeah, that was one of the first Blurays that ever came out, as I recall. Another issue that you often see with those early ones is that they're actually encoded with the MPEG-2 video codec (H.262), same as DVDs. That's allowed under the Bluray spec, but of course anything released these days is going to use H.264 with vastly better picture quality as a result.

Re: Adventures with ffmpeg and color ranges

#93

Post by brokenmachine » Thu, May 30, 2019, 2:13 AM UTC

zaroth wrote: post #33

brokenmachine wrote: post #25

Earlier quoted context omitted.

>I have a high end OLED screen in a very dark room, and I was very disappointed by the picture quality. Unfortunately for you, high end OLED in a very dark room is literally the most likely conditions under which you'd be annoyed by these problems... :-) HDR is the way to go.

It’s Dolby Vision from the ATV to the set, it’s the source encoding I assume that just couldn’t live up to material. Perhaps bitrate compromises have to be made when you’re streaming to so many people at once, but it’s not usually so glaring.

Oh, that's surprising. If it is truly Dolby Vision then the dynamic metadata should cope very well with darker scenes, so it must be either the source material or the compression for streaming.

It will be interesting to see if it looks better when a higher-quality Bluray version comes out.

Re: Adventures with ffmpeg and color ranges

#94

Post by jacobush » Thu, May 30, 2019, 8:34 AM UTC

bscphil wrote: post #92

jacobush wrote: post #57

Earlier quoted context omitted.

Wow! Talladega nights was the first movie I saw on a Bluray setup. (PS3 at a friends.) I was shocked at how badly mastered it was. It sounds exactly like that problem. Everything was washed out.

Yeah, that was one of the first Blurays that ever came out, as I recall. Another issue that you often see with those early ones is that they're actually encoded with the MPEG-2 video codec (H.262), same as DVDs. That's allowed under the Bluray spec, but of course anything released these days is going to use H.264 with vastly better picture quality as a result.

I didn’t know about MPEG2 in Bluray. Still, with higher bitrate?