Youtube already has it's own HDR video codec with VP9. Also, HDR10+ and Dolby Vision aren't HDR formats, they're formats for storing dynamic metadata that can help TVs better display HDR video. The article seems to misinterpret what their purpose is. HDR video can be presented just fine without HDR10+ or Dolby Vision.
So if VP9 and AV1 already store HDR data, How is Dolby Vision used? Its HDR metadata shipped alongside video formats that don't already encode this data?
Like if I stream netflix to a TV supporting Dolby Vision what format is the video being streamed in and is the TV manufacturer just paying Dolby for the right to correctly decode this HDR info then?
Dolby Vision supplements the HDR data already present in a video. For example, when you buy a Blu-ray disc that supports Dolby Vision, the disc contains several m2ts files containing HEVC encoded videos. Present within the HEVC stream is also the metadata, which supplies metadata for each frame. To see what this data is, I used[1], and then got the info for frame 1000 and saved it as a json in this [2] pastebin. As you can see, it contains info regarding the minimum and maximum PQ encoded values, the coefficients of the ycc to rgb matrix, among other things. This allows TVs to better display the HDR data, as currently, video data encoded using rec. 2020 color primaries with max light level of 10000 nits is far outside what current TVs are capable of displaying, so metadata showing max pq of a frame or scene allows these devices to make better decisions.
Dolby Vision is a format of that metadata - it's hiding either at the beginning or as part of a frames in proprietary metadata extensions. When the video is being played, this metadata is extracted by video decoder (or demuxer) and then sent together with video frames to the display where the display then applies the
(color, etc.) metadata to correctly show the frames based on its capabilities.
Since the format of this metadata is proprietary, the demuxers, decoders and displays need to understand it and properly apply it when rendering. That's the part that needs to be implemented and paid for.
But that's really not all of the technology - Dolby Vision isn't just the metadata format, it's also definition of how the videos are mastered and under which limitations (e.g. DV allows video to be stored in 12-bit per pixel format, allows mastering with up to 10.000 nits of brightness for white pixels and defines wider color range so better, brighter colors can be displayed by a panel capable of doing that).
https://www.elecard.com/page/article_hdr is actually a pretty good article that overviews this topic (although you do need a basic understading how digital video encoding works).
> HDR video can be presented just fine without HDR10+ or Dolby Vision.
To see HDR content at its full dynamic range, you'll need an HDR-capable device or display. Viewers watching on non-HDR devices/displays will see an SDR¹ video derived from the HDR source.
¹ "Standard dynamic range" or "smooshed dynamic range"
> To see HDR content at its full dynamic range, you'll need an HDR-capable device or display.
Not exactly - you need an HDR Mastering display to see HDR content at full dynamic range. There are essentially no high volume consumer-level devices, with the exception of maybe Apple's XDR lineup (MBP, iPad, iPhone, Pro Display) with the capability of displaying non-windowed HDR content at full brightness.
Everything else relies on tone mapping, even the latest 2022 OLED & QDOLED TVs.
Even HDR mastering monitors can only reach 2000 to 4000 nits [1], whereas PQ gamma goes up to 10000 nits. This is why most hdr streams contain metadata containing mastering display peak luminance.
Linus Tech tips talked about it. HDR on YouTube is a nightmare. There's no way to know if it'll come out in the right colours or get crushed into an ugly mess.
The entire points of Dolby Vision is that it should give you the same image no matter what display you display it on, if the device is capable of displaying it. It’s an absolute format of light and color values, rather than a format based on RGB values.
