# Dolby Vision

Dolby Vision is a set of technologies developed by Dolby Laboratories for high dynamic range (HDR) video. It covers content creation, distribution, and playback. It includes dynamic metadata that define the aspect ratio and adjust the picture based on a display's capabilities on a per-shot or even per-frame basis, optimizing the presentation.
Dolby Vision was introduced in 2014, making it the first available HDR format. HDR10+ is a competitor HDR format that also uses dynamic metadata.
Dolby Vision IQ is an update designed to optimize Dolby Vision content according to the ambient light.
Dolby Cinema also uses Dolby Vision in conjunction with Dolby Atmos sound systems, though because of the use of 2.6 gamma and thus 48 nits in SDR cinemas, the 108 nits used in Dolby Cinema is already HDR.

## Description

Dolby Vision allows for a maximum resolution of 8K, up to 12-bit color depth, and maximum peak brightness of 10,000 nits. However, according to the Dolby Vision white paper, as of 2018 professional reference monitors, such as the Dolby Vision HDR reference monitor, are currently limited to 4,000 nits of peak brightness.
Dolby Vision includes the PQ transfer function, a wide-gamut color space (ITU-R Rec. BT.2020 in YC$_B$C$_R$ or IPTPQc2), up to 8K resolution, and for some profiles (FEL) up to 12-bit. It can encode mastering display colorimetry information using static metadata (SMPTE ST 2086) and also provide dynamic metadata (SMPTE ST 2094-10, Dolby format) for each scene or frame.
This dynamic metadata allows adjusting of the image on a scene-by-scene or even frame-by-frame basis. These adjustments, called "trims" in Dolby's support documents, include parameters such as Lift, Gamma, Gain, Saturation, Chroma Weight, and so on. Each set of trims is specific to its respective target displays defined by nits and colorspace. Image aspect ratios can also be defined on a per-shot basis.

## Technical details

The Dolby Vision format is capable of representing videos with a peak brightness up to 10,000 cd/m$^2$ and a color gamut up to Rec. 2020. Current displays cannot reproduce the full Dolby Vision brightness and gamut capability. There are no brightness and color gamut capability requirements for consumer displays. When the consumer display has lower color volume than the mastering display, the content is adjusted to the consumer display capability based on the dynamic metadata.
Dolby Vision mastering displays require:
* EOTF: PQ
* Peak brightness: at least 1,000 cd/m$^2$
* Black level: at most 0.005 cd/m$^2$
* Contrast ratio: at least 200,000:1
* Color gamut: at least 99% of P3

### Metadata

Dolby Vision metadata include:
* L0 (static): Mastering and target display characteristics
* L1 (dynamic): Automatically generated
* L2 trims (dynamic): Manually generated per frame or per scene
* L3 trims (dynamic): Manually generated per frame or per scene (since CMv4.0)
* L8 trims (dynamic): Manually generated per frame or per scene (since CMv4.0) (equivalent of L2 trims)
* L5: Timeline aspect ratio description
* L6 (static and optional): MaxCLL and MaxFALL (required for HDR10)
* L9 (dynamic): Mastering display color primaries (since CMv4.0)
Dolby Vision 4.0 introduces new secondary trims for hue and saturation adjustment.

### Profiles

Dolby Vision profiles :
| Profile | Codec | BL:EL resolution | Backward compatibility |
| 4 | 10-bit HEVC | 1:1/4 | SDR |
| 5 | 10-bit HEVC | No enhancement layer | None (It uses proprietary IPTPQc2) |
| 7 | 10-bit HEVC | 1:1/4 for UHD 1:1 for FHD | Ultra HD Blu-ray |
| 8 | 10-bit HEVC | No enhancement layer | HDR10 or SDR or HLG |
| 9 | 8-bit AVC High or High Progressive Profile | No enhancement layer | SDR |
| 10 | 10-bit AV1 | No enhancement layer | None or HDR10 or SDR or HLG |
| 20 | 10bit MV-HEVC for 3D or HEVC for 2D | No enhancement layer | None (It uses proprietary IPTPQc2) |
Profiles not supported for new applications :
| Profile | Codec | BL:EL resolution | Backward compatibility |
| 0 | AVC | 1:1/4 | SDR |
| 1 | AVC | 1:1 | None |
| 2 | 8-bit HEVC | 1:1/4 | SDR |
| 3 | 8-bit HEVC | 1:1 | None |
| 6 | 10-bit HEVC | 1:1/4 | HDR10 |
| 8 | 10-bit HEVC | No enhancement layer | |

### Dual layer

Some Dolby Vision profiles are dual layer (for example: the profile 7 used for Ultra HD Blu-ray). The base layer (BL) and the enhancement layer (EL) are combined to produce a 12-bit video stream.
The enhancement layer can be full enhancement layer (FEL) or minimum enhancement layer (MEL).

### File formats

* ISO Base Media File Format
** MP4
** DECE
** Common File Format (CFF)
** Protected Interoperable File Format (PIFF)
* HTTP Live Streaming
* MPEG-2 Transport Stream Format
* MPEG-DASH
* MKV

## License

Dolby Vision is a proprietary solution by Dolby.
In 2021, compatible color grading systems can create Dolby Vision automatic metadata with no additional cost for content creators. A $2,500 annual license is required to activate the trims allowing content creators to manually adjust the video. OEM and manufacturer of a grading, mastering, editorial, or other professional application or device need to apply for a license.
Dolby SVP of Business Giles Baker has stated that the royalty cost for Dolby Vision is less than $3 per TV.
Despite the proprietary nature, several free software implementations of Dolby Vision exist (see § Software).

## Adoption
### Hardware

* Televisions:
** Hisense
** LG
** Panasonic
** Philips
** Sony
** TCL
** Vizio
* Monitors:
** ASUS
* Smartphones:
** Display:
*** LG G6
*** iPhone 8/8 Plus, X, XS/XS Max, XR, 11, 11 Pro/11 Pro Max, SE (2nd generation), 12/12 mini, 12 Pro/12 Pro Max and 13/13 mini, 13 Pro/13 Pro Max.
*** Xiaomi: Mi 11 Ultra, Mi 11 Pro
** Camera:
*** iPhone 12/12 mini, 12 Pro/12 Pro Max, iPhone 13/13 mini, 13 Pro/13 Pro Max, iPhone 14/14 Plus, 14 Pro/14 Pro Max, and iPhone 15/15 Plus, 15 Pro/15 Pro Max.
*** Xiaomi 12S Ultra
*** Xiaomi MIX Fold 2
*** Xiaomi 13
*** Xiaomi 13 Pro
*** Vivo X90 Pro+
* Gaming consoles:
** Xbox One X/S: Streaming apps only.
** Xbox Series X/S: Streaming apps and gaming.
* Other:
** Apple Vision Pro
** Nvidia Shield TV (from 2019)

### Content distribution

* Ultra HD Blu-ray
* Streaming services
** Vimeo: Only for Apple devices
** Netflix
** Disney+
** Hulu
** HBO Max
** Amazon Prime Video
** Bilibili

### Software

* Media players:
** mpv, the first free software player to support Profile 5
** Libplacebo (part of the VideoLAN project) has support for Dolby Vision Profile 5's IPTPQc2 color space, MMR and reshaping, but no current support for dynamic metadata or NLQ
** MPC-HC has partial support (profiles 5, 8.1, 8.4) through MPC Video Renderer
** Exoplayer
** Shaka Player (device dependent)
** Windows 10/11 built-in media players (Dolby Vision Extension required, profiles 4/5/8/9 only)
* Encoders:
** x265: Profile 5, profile 8.1 and profile 8.2 (since version 3.0)
* Color grading software:
** Autodesk Lustre
** Autodesk Flame 2021
** Blackmagic Design Davinci Resolve
** Digital Vision Nucoda
** Filmlight Baselight
** Grass Valley RIO
** SGO Mistika