4 ms·

Keep in mind that for historical reasons related to the way analog TVs used to work, black in video is almost never "#000". We call that setup, or superblack. I

Keep in mind that for historical reasons related to the way analog TVs used to work, black in video is almost never "#000". We call that setup, or superblack. In the analog days NTSC black was 7.5 IRE, not 0, which is why you could always tell when a television was turned on even with nothing on the screen. More than one digital standard kept this custom, setting black at (roughly, in your terms) "#111". So if you're seeing encoding artifacts or grayness on black video, that's more a legacy of video itself and not the encoding work done by whoever made the media. Say I sit down at a switcher and push the Black button. You'd think nothing would come out, right? Not quite: that switcher will almost always emit broadcast black, not "null," whether it's analog or digital. Sure, you can probably get Photoshop to spit out 0% then encode in some codec that lets you keep 0% and successfully display it on a modern digital television, but the more equipment and encodes you add to a video production the more likely the signal will be pulled up to broadcast black, so it's better to just think of that as black. There's a similar exercise with white on the upper end. Remember when analog TVs would buzz when you wired up your computer and put RGB white on the screen? That's superwhite.

Buge 9y ago
Well you should still be outputting full contrast. If it's not displaying black as fully black on your screen, there's a problem somewhere, probably in your playback software. In MPC there's an option Render Settings > Output Range > 0-255 or 16-235. When set to 0-255 (default) my videos play with full black.
- jsmthrowaway 9y ago
  That setting sounds like it's for clamping your output to drive analog televisions in case your media has supercolors in it, given its default. I mean, putting a lens cap on a camera will record 16, and a white title on black in most editors will use 235 white on 16 black. I'm not sure what you think that setting is doing in that circumstance, when playing "typical" media. It definitely shouldn't be scaling, because that would distort intended color.
  - sbierwagen 9y ago
    A unique pleasure of HN is watching programmers try to argue with domain experts on the topic of their domain expertise.
    - brigade 9y ago
      Domain experts sometimes don't realize when their knowledge is out of date. To wit: HDMI does allow for 0-255 (or 1023, etc) "full range" quantization instead of the default "limited range" of 16-235 for most CEA-861 formats, if the sink's EDID allows a selectable YCC quantization range and the source sends AVI YQ=1. Or even getting to the "plain black image full #000" remark that prompted this thread, images are basically always full range where black is 0 and there is no "superblack" concept. If it's being transmitted over HDMI, it's up to the GPU to do range conversion and RGB/YCbCr conversion as necessary, and up to the OS to do ICC colorspace conversion as necessary.
      - jsmthrowaway 9y ago
        > Domain experts sometimes don't realize when their knowledge is out of date. Sigh. Another unique pleasure of HN. Sometimes there's a difference between practical and possible. I did not say it was not possible. While you're technically correct, the worst kind of correct, very little content and few delivery systems actually utilize that capability -- look how much you had to type just to get there. Then how are you going to deliver that alternate colorspace content? To wit: I note you've overlooked ATSC and other delivery mechanisms, as well as HDMI being a specification designed to handle all cases including non-NTSC-legacy regions which had a different colorspace all along (notably PAL, which defined "blanking" and "black" as equivalent). Practically speaking, pretty much no content you'll ever play makes use of wide gamut in North American contexts. If you're cooking a file for yourself, that's one thing, but once you're producing something that's mass consumed there's a lot of compatibility issues to worry about. We still have fractional frame rates and picture safe zones, for crying out loud, despite drop frames being pointless for decades and overscan being a word nobody under 30 has heard. What's the point of leveraging wide gamut in HDMI if all your capture equipment, editing tech, broadcast delivery, playback equipment, and displays cannot handle it? For the general case you're counting on Vizio adding that ability into a $200 TV and Comcast handling it in their CPE. Good luck. Why does that matter? When producing video content handling a wide array of distribution media matters. Except for circumstances where you control the entire system end to end, such as a planetarium or some other kind of venue, you always have to plan for your content potentially being sent over lame, legacy-style HDTV broadcasting. That's the floor. Sometimes you even have to think about SDTV transmission; God help you, and have fun with chyrons... Not even Rec. 2020, which is designed for UHD and is way better, changed this[0]. It's not a concept that's in dispute, despite whatever HDMI -- one standard of several hundred that are involved in delivering you a single TV broadcast -- can do. [0]: https://en.wikipedia.org/wiki/Rec._2020#Digital_representation https://en.wikipedia.org/wiki/Rec._2020#Digital_representati...

Buge 9y ago

Well you should still be outputting full contrast. If it's not displaying black as fully black on your screen, there's a problem somewhere, probably in your playback software. In MPC there's an option Render Settings > Output Range > 0-255 or 16-235. When set to 0-255 (default) my videos play with full black.

jsmthrowaway 9y ago
That setting sounds like it's for clamping your output to drive analog televisions in case your media has supercolors in it, given its default. I mean, putting a lens cap on a camera will record 16, and a white title on black in most editors will use 235 white on 16 black. I'm not sure what you think that setting is doing in that circumstance, when playing "typical" media. It definitely shouldn't be scaling, because that would distort intended color.
- sbierwagen 9y ago
  A unique pleasure of HN is watching programmers try to argue with domain experts on the topic of their domain expertise.
  - brigade 9y ago
    Domain experts sometimes don't realize when their knowledge is out of date. To wit: HDMI does allow for 0-255 (or 1023, etc) "full range" quantization instead of the default "limited range" of 16-235 for most CEA-861 formats, if the sink's EDID allows a selectable YCC quantization range and the source sends AVI YQ=1. Or even getting to the "plain black image full #000" remark that prompted this thread, images are basically always full range where black is 0 and there is no "superblack" concept. If it's being transmitted over HDMI, it's up to the GPU to do range conversion and RGB/YCbCr conversion as necessary, and up to the OS to do ICC colorspace conversion as necessary.
    - jsmthrowaway 9y ago
      > Domain experts sometimes don't realize when their knowledge is out of date. Sigh. Another unique pleasure of HN. Sometimes there's a difference between practical and possible. I did not say it was not possible. While you're technically correct, the worst kind of correct, very little content and few delivery systems actually utilize that capability -- look how much you had to type just to get there. Then how are you going to deliver that alternate colorspace content? To wit: I note you've overlooked ATSC and other delivery mechanisms, as well as HDMI being a specification designed to handle all cases including non-NTSC-legacy regions which had a different colorspace all along (notably PAL, which defined "blanking" and "black" as equivalent). Practically speaking, pretty much no content you'll ever play makes use of wide gamut in North American contexts. If you're cooking a file for yourself, that's one thing, but once you're producing something that's mass consumed there's a lot of compatibility issues to worry about. We still have fractional frame rates and picture safe zones, for crying out loud, despite drop frames being pointless for decades and overscan being a word nobody under 30 has heard. What's the point of leveraging wide gamut in HDMI if all your capture equipment, editing tech, broadcast delivery, playback equipment, and displays cannot handle it? For the general case you're counting on Vizio adding that ability into a $200 TV and Comcast handling it in their CPE. Good luck. Why does that matter? When producing video content handling a wide array of distribution media matters. Except for circumstances where you control the entire system end to end, such as a planetarium or some other kind of venue, you always have to plan for your content potentially being sent over lame, legacy-style HDTV broadcasting. That's the floor. Sometimes you even have to think about SDTV transmission; God help you, and have fun with chyrons... Not even Rec. 2020, which is designed for UHD and is way better, changed this[0]. It's not a concept that's in dispute, despite whatever HDMI -- one standard of several hundred that are involved in delivering you a single TV broadcast -- can do. [0]: https://en.wikipedia.org/wiki/Rec._2020#Digital_representation https://en.wikipedia.org/wiki/Rec._2020#Digital_representati...