[HN Gopher] Support HDR images in your app [video]
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       Support HDR images in your app [video]
        
       Author : janandonly
       Score  : 48 points
       Date   : 2023-10-06 17:49 UTC (5 hours ago)
        
 (HTM) web link (developer.apple.com)
 (TXT) w3m dump (developer.apple.com)
        
       | Moldoteck wrote:
       | Idk if iphones have this problem, but on Android, insta reels are
       | so messed up bc of hdr. I'm watching em at night with low
       | brightness and suddenly a hdr video pops out and it brightens my
       | eyes to oblivion... And this issue is present for years
        
         | altairprime wrote:
         | I tested and it looks like the iPhone lowers the peak nits
         | based on the brightness slider, so the HDR reels aren't "max
         | phone brightness" bright, like they're trying to be. Dunno how
         | that compares, but yes, it's present to some degree. (Low Power
         | Mode disables EDR, which works around it, but has other effects
         | as well.)
        
       | Night_Thastus wrote:
       | HDR is such a clusterf*ck right now.
       | 
       | Especially with monitors. I am so sick of every monitor with Vesa
       | HDR-400 claiming they're an "HDR" monitor. I'm sorry, but that
       | standard is garbage. It's so bad it's meaningless.
       | 
       | Not only is that a pathetic amount of brightness, but the local
       | dimming required is just awful. You can have a screen with a
       | whopping 4 zones that react terribly and slap an HDR label on it.
       | 
       | HDR-600 is barely any better, frankly.
        
         | Trigg3r wrote:
         | Have had 3 monitors claiming "HDR-400" now; all look equally as
         | shit with HDR enabled in Windows & Gaming, first two where
         | between PS120 - PS250, third was a "premium" monitor @ PS500.
         | Current "HDR" can get te fuck ;)
        
           | formerly_proven wrote:
           | Most of these are IPS and struggle reaching contrast ratios
           | of 700:1 and black levels darker than noon. Some of the LG
           | ones barely manage 500:1 in sRGB mode...
        
             | Trigg3r wrote:
             | All 3 have been VA to be fair. I do wonder if have missed a
             | trick with IPS but have been lead to believe VA has the
             | speed (and HDR as a plus)? that is kind of the point though
             | I suppose, buying a "HDR ready screen" - it's been a real
             | pain for a few years now from what I have seen >_<
        
         | [deleted]
        
         | Culonavirus wrote:
         | The standard may suck due to too few local dimming zones, but
         | the "pathetic amount of brightness" is a hard "for you" kind of
         | deal. It depends on your use case.
         | 
         | I use an LG OLED TV as a monitor for work (and a game here and
         | there), 4k 120Hz and I'm more than happy with the brightness in
         | HDR content. In fact, it's kind of just at the edge of being
         | too bright for me... given the distance.
        
           | Night_Thastus wrote:
           | My complaint about HDR 400 was mostly with LCD monitors, not
           | OLEDs. OLEDs may not get bright, but at least they get
           | infinite contrast and perfect blacks.
           | 
           | That's a huge improvement compared to a lot of the garbage
           | HDR 400 rated LCD monitors.
        
         | crazygringo wrote:
         | Not just monitors but video players too.
         | 
         | Trying to play HDR content on a regular SDR screen is a mess.
         | 
         | If you rip an HDR version of a movie:
         | 
         | - VLC does nothing. It shows it as so dark it's unwatchable
         | 
         | - IINA shows it as brightness comparable to an SDR version of
         | the movie, but with a weird green tint
         | 
         | - QuickTime is weirdly in-between, brighter than VLC but not as
         | bright as an SDR version
         | 
         | - Infuse got fixed this year so that it plays HDR content to
         | visually match the SDR version of the same content on a SDR
         | screen (the _only_ player I 've found that can on Macs)
         | 
         | And if you want to convert your file in ffmpeg, good luck. I
         | still haven't found the magic settings that reverses whatever
         | entertainment studios are doing to translate their SDR into
         | HDR. (The magic settings that Infuse has somehow figured out.)
         | There's no flag or setting for it -- you have to input a bunch
         | of custom values.
        
           | lldb wrote:
           | mpv with --tone-mapping=bt.2446a (or whichever you like from
           | https://mpv.io/manual/stable/#options-tone-mapping), --hdr-
           | compute-peak=yes, and --target-peak=SDR monitor nits, does
           | the best I've seen yet.
        
           | PaulBGD_ wrote:
           | Plex does a fairly good conversion too, iirc using ffmpeg.
        
           | zimpenfish wrote:
           | I can't remember where I found this but it's what I've been
           | using to downscale and convert the occasional 10bit downloads
           | (using the nvenc GPU acceleration.)                   ffmpeg
           | -hide_banner -y -probesize 100M -i "$file" -map 0:v:0 -c:v
           | h264_nvenc -x264-params b_pyramid=2:ref=4:vbv-
           | maxrate=30000:vbv-bufsize=15000 -refs 4      -crf 17
           | -preset:v fast -profile:v high -b_strategy 2 -rc-lookahead
           | 900 -level 4.1 -pix_fmt yuv420p -color_range 1 -colorspace 1
           | -color_primaries bt709 -color_trc bt709 -subq 10 -vf zscale=t
           | in=smpte2084:min=bt2020nc:pin=bt2020:rin=tv:t=smpte2084:m=bt2
           | 020nc:p=bt2020:r=tv,zscale=t=linear,format=gbrpf32le,zscale=p
           | =bt709,tonemap=tonemap=hable:desat=0,zscale=t=bt709:m=bt709:r
           | =tv,format=yuv420p,zscale=s=1280x720 -c:a copy output.mkv
        
         | wilg wrote:
         | What's the * stand for?
        
           | clnq wrote:
           | Impossible to know.
        
           | Night_Thastus wrote:
           | It's a regex wildcard symbol.
        
       | chongli wrote:
       | Has anyone actually used a decent HDR display? I'm really
       | skeptical of the technology. I really don't want websites and
       | videos to be able to display blindingly bright white and other
       | pure colours on my screen. I like things to be readable and not
       | painful to look at.
        
         | baq wrote:
         | Any OLED display since 2015ish. I've got a 2017 LG C7 and it's
         | amazing to this day.
        
           | Night_Thastus wrote:
           | OLEDs have amazing blacks and great contrast, but they truly
           | struggle to get bright. That still isn't solved, at least to
           | my satisfaction. They can get bright briefly or in small
           | areas of the screen, but tend to crunch the brightness a lot
           | otherwise.
        
             | baq wrote:
             | Yeah I do pull the curtains down to watch tv during the
             | day. Don't care too much since I rarely have time when the
             | sun's up. At night it's absolutely stunning when the
             | content's right.
        
         | sgt wrote:
         | Any new or recent iPhone. When I first got my 14 Pro and
         | displayed a photo with HDR I was blown away.
        
         | FL410 wrote:
         | Yes. The HDR on a recent Macbook Pro is the real deal, and
         | unmistakable when you see it. Same with modern OLED HDR TVs -
         | they can get so bright it hurts.
        
           | Night_Thastus wrote:
           | What OLEDS have decent brightness? OLEDS really struggle with
           | that because of burn in. They can get temporarily bright, or
           | bright in tiny zones, but in less than ideal conditions they
           | crunch it right down.
        
             | astrange wrote:
             | LEDs have separate backlights, which is good for getting
             | brighter but bad for contrast because they can't get as
             | dark as OLEDs.
             | 
             | I think the reason you don't want to drive OLEDs as hard
             | (so there's current limitation/ABL) is more about burn-out
             | than burn-in.
        
             | [deleted]
        
           | iteratethis wrote:
           | I'm sure you mean LED TVs. OLED TVs are notorious for having
           | a limited brightness. Only since 2022 are there some newer
           | panels (called OLED.ext) that can do decent HDR.
        
           | cwillu wrote:
           | > they can get so bright it hurts.
           | 
           | I regret that hn doesn't have HDR support so as to properly
           | emphasize that <em><blink><pain>THIS IS NOT A
           | FEATURE.</pain></blink></em>
        
             | mort96 wrote:
             | It would have been a pretty nice feature though, if it
             | could've been used to uniformly make SDR content brighter,
             | to make the laptops more useful in sunlight and with
             | sunglasses. Too bad that's not a feature (I'm guessing
             | because it wear out the screen or something).
        
               | chongli wrote:
               | _sunlight and with sunglasses_
               | 
               | No thank you! If I'm outside enjoying the sun with
               | sunglasses on then I have zero interest in using a
               | laptop!
        
               | mort96 wrote:
               | Sure, but there are also times when the desire to do
               | something computery is greater than the desire to be
               | outside. In those situations, it's a choice between being
               | inside with a computer or being outside with a computer.
        
         | NovemberWhiskey wrote:
         | Do you use an OLED iPhone?
        
         | Night_Thastus wrote:
         | If you're willing to sacrifice everything else (including
         | money), yes, there are some nice HDR displays. Get something
         | with HDR1000 standard or above. Get something with FALD and a
         | LOT of zones. Make sure to check its color space coverage. Look
         | at independent reviews. Be prepared to spend at least a couple
         | grand.
         | 
         | But you'll have to turn HDR on and off depending on the content
         | you're looking at. If you're looking at SDR content, it will
         | look wrong if the display is in HDR mode. That sucks, and I
         | hope some day is properly fixed.
         | 
         | OLED is also nice because it has perfect blacks (no local
         | dimming needed), but it struggles with brightness, which is the
         | other half of HDR. We still haven't figured out how to get
         | both.
        
           | astrange wrote:
           | You don't have to turn HDR on and off if the OS does color
           | management correctly. But of course only Apple platforms do
           | this.
        
         | mort96 wrote:
         | I think my laptop has a decent HDR display? It's a MacBook Pro
         | 14" with "Liquid Retina XDR" as they call it. I think HDR
         | content looks more or less ... as intended.
         | 
         | I think it's terrible. The only time I even remember that HDR
         | is a thing is when some embedded video in a web page gets much
         | brighter than the rest of the screen and the rest of the screen
         | looks dim as a result. It's never a "wow that sun looks
         | amazing" style experience, it's always a "wow most of my screen
         | just got really dark" style experience.
         | 
         | I think maybe HDR has a place in movies and TV shows and even
         | maybe YouTube style videos (not that I've experienced that),
         | but I think enabling HDR for small video embeds on a web page
         | was a terrible decision.
        
           | Night_Thastus wrote:
           | It's because trying to view SDR content on an HDR display
           | doesn't work. It will look like garbage. You have to turn HDR
           | on and off depending on what content you view.
        
             | wlesieutre wrote:
             | Have you tried it on a Mac laptop? The OS will
             | transparently boost the backlight brightness while shifting
             | the white point of the non-HDR content down so that
             | everything else on screen is completely unaffected.
             | 
             | It's very different from the experience I've had in Windows
             | where if you enable the HDR setting everything looks shitty
             | and washed out.
        
             | Toutouxc wrote:
             | On Apple displays you don't have to turn HDR on or off,
             | it's available all the time. SDR content is displayed as
             | usual (exactly like everything looked 10 years ago) and HDR
             | content can sit directly next to it and use whatever
             | brightness headroom is available for extended dynamic
             | range. It's totally seamless and transparent, but the
             | experience can make the user think that SDR content is
             | getting darker as their eyes adjust to HDR.
        
               | Night_Thastus wrote:
               | That must be nice. Hopefully the rest of the world
               | catches up to that.
        
           | baq wrote:
           | What you've described is absolutely not anywhere close to
           | decent.
           | 
           | Right now it's basically OLED in a dark room or don't bother.
           | Large TVs can get away with FALD, maybe.
        
         | lexlash wrote:
         | For productivity/reading, I want one of the new eInk screens.
         | For gaming and video, the HDR OLED displays I have (LG and
         | Dell) look incredible. Mixed content looks awful, just like
         | mixes of high DPI UIs rendering low DPI websites.
         | 
         | Windows HDR support is a very mixed bag, just like their early
         | support for high DPI, and I think that's probably what leads
         | some reviewers to dismiss it.
        
           | clnq wrote:
           | Windows struggles with HiDPI?
        
       | nchase wrote:
       | Naive question: why is this newsworthy? What are the
       | implications?
        
         | adzm wrote:
         | HDR and higher bit colors are becoming more popular but are
         | still very much a mess from the consumer and software developer
         | standpoint.
        
         | altairprime wrote:
         | The original title referred to Apple's endorsement of an
         | upcoming ISO standard that defines how to represent HDR images
         | within existing still image file formats such as JPEG-XL and
         | HEIF. It turns out that there _isn't_ any such finalized
         | standard -- unlike, for example, BT.2020 in the moving image
         | file formats space.
         | 
         | So, presumably, the existence of a standard under development
         | -- and the endorsement of it by a major manufacturer of cameras
         | and displays -- was considered newsworthy by the OP.
        
         | [deleted]
        
       | dang wrote:
       | The submitted title was "Apple put their weight behind an open
       | HDR standard called "ISO/TS 22028-5"" but that broke the HN
       | guideline against editorializing: " _Please use the original
       | title, unless it is misleading or linkbait; don 't
       | editorialize._" -
       | https://news.ycombinator.com/newsguidelines.html
       | 
       | If you want to say what you think is important about an article,
       | that's fine, but do it by adding a comment to the thread. Then
       | your view will be on a level playing field with everyone else's:
       | https://hn.algolia.com/?dateRange=all&page=0&prefix=false&so...
        
         | wilg wrote:
         | I simply wouldn't have looked at this with the new title. The
         | original title was better. The new title deletes the
         | interesting insight about the format they are using. Now it
         | just looks like a video about general HDR workflow and I don't
         | know why it's been posted. The newsworthy element may not be
         | the entire link but some element on the page, especially for
         | longer form content.
        
           | altairprime wrote:
           | Submitting a blog post about this would have been much more
           | effective than linking an Apple developer video with a
           | modified title. (And, then I wouldn't have had to add quotes
           | and context as a comment below.)
        
             | wilg wrote:
             | Arguably, everything worked out fine until the title
             | changed.
        
               | pvg wrote:
               | It didn't - one of the main reasons you can't make up
               | your own title is that it acts as a kind of mega-comment
               | over everyone else's comments. If you want to just
               | comment, write a regular comment. If you want your own
               | title with your own commentary, write your own commentary
               | and submit it to HN with your title.
               | 
               | What you can't do is use someone else's stuff to make
               | your commentary more important.
        
               | wilg wrote:
               | Well, it wasn't really commentary though. It was a
               | pointer to the interesting information in the link.
        
               | pvg wrote:
               | That's commentary/editorializing. Nothing wrong with
               | these things, you just don't get to do them in the title
               | for the reasons mentioned in the previous comment.
        
           | xd1936 wrote:
           | Agreed. Original title was not clickbait or misleading in any
           | way.
        
             | pvg wrote:
             | "original title" means the original title of the article,
             | not the title the submitter originally made up.
        
               | tormeh wrote:
               | That's the original title of the submission, though.
        
               | pvg wrote:
               | Yes but the guideline about 'original title' doesn't mean
               | that. That's the editorialized title, not the original
               | title of the thing. What you're suggesting is
               | misconstruing the guideline to mean the opposite of what
               | it actually means.
        
           | dang wrote:
           | A good place to explain why an article is being posted is by
           | adding a comment to the thread.
        
             | wilg wrote:
             | No it isn't, because you can't see that from the main page
             | so there's no reason to look at the link or comments if you
             | don't know what is interesting about the post. This rule
             | makes sense for editorialized titles, but not as much for
             | trying to point to news that is buried in some larger page
             | that does not have a useful title.
        
         | ShamelessC wrote:
         | Putting a notice either like this or as an indicator on the
         | submission would go a long way towards reducing (my)
         | frustration with moderation's title edits.
        
           | dang wrote:
           | The problem with that is that there are many such notices and
           | indicators we might put up about many things. If we did all
           | of them, the site would get messier and more annoying and
           | nannyish.
           | 
           | It seems generally better (or at least in keeping with HN's
           | 'DNA') to err on the side of keeping things minimal and trust
           | users to figure them out.
        
             | ShamelessC wrote:
             | That's fair. I was thinking something in the realm of a
             | bolded asterisk next to the title. Or something similarly
             | subtle with an explanation in the rules perhaps. Obviously
             | there are users who would meta comment about this each time
             | it happened (as is happening currently), so I can
             | understand the reluctance.
        
       | [deleted]
        
       | altairprime wrote:
       | ISO/TS 22028-5:2023 Photography and graphic technology --
       | Extended colour encodings for digital image storage, manipulation
       | and interchange -- Part 5: High dynamic range and wide colour
       | gamut encoding for still images (HDR/WCG)
       | 
       | https://www.iso.org/standard/81863.html
       | 
       | Note that, in this specification's title, "HDR" refers to
       | luminosity ranges that are broader than sRGB supports, and "WCG"
       | refers to colorspaces that are broader than sRGB supports.
       | 
       | Apple's video is focused on the HDR component of still images,
       | which is relatively new and not yet finalized into any ISO or W3C
       | standards.
       | 
       | Support for WCG images is already widespread courtesy of ICC
       | profiles, though many holdouts (such as Slack and Discord)
       | continue to damage WCG images posted to their services.
       | 
       | Quoting Apple's video transcript at this time index:
       | 
       | https://developer.apple.com/wwdc23/10181?time=205
       | 
       | > _This specification, TS22028-5, provides a structure for
       | encoding HDR content into existing still image formats without
       | compromising quality._
       | 
       | > _The specification requires Hybrid Log-Gamma, HLG, or
       | Perceptual Quantizer, PQ, as the encoding transfer function.
       | These are functionally analogous to the gamma curves used in SDR
       | images._
       | 
       | > _The color primaries for ISO HDR files are the BT.2020
       | primaries_
       | 
       | > _HDR images are required to be 10 bits or more per component.
       | This means that some formats, like HEIF, can encode HDR, but some
       | others, like traditional JPEG, are not able to be 22028-5
       | compliant, as they only support 8 bits per component._
       | 
       | PNG _only_ supports 8-bit or 16-bit, making it quite inefficient
       | for 10- and 12-bit HDR. However, JPEG-XL seems to support 10 bits
       | or more per component. This may provide supporting context for
       | why Apple began supporting a new image format this fall.
       | 
       | > _for required metadata, both traditional ICC profiles and CICP
       | tags are valid._
        
         | the8472 wrote:
         | Isn't that just BT.2100?
        
           | turnsout wrote:
           | Yeah, it does appear to be a reiteration of Rec. 2100 /
           | BT.2100. I wonder if it's because this refers to still images
           | rather than video?
        
             | altairprime wrote:
             | Yes, that's why:
             | 
             | https://stage.color.org/hdr/07-Nicolas_Bonnier.pdf (slide
             | "Motivations"):
             | 
             | > _Several attempts to use PQ /HLG and BT.2020 for still
             | photography are surfacing_
             | 
             | > _But so far, the digital still imaging industry has not
             | settled on a reference HDR /WCG image encoding for
             | consumers_
             | 
             | > _The purpose of TS 22028-5 is to provide requirements and
             | guidelines for HDR /WCG colour encoding of still images_
             | 
             | And a bit further down, referring specifically to BT.2100:
             | 
             | > _Shall use ITU-R BT.2020 /2100-2 colour primaries_
        
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