This article may be too technical for most readers to understand.(September 2023) |
Inception | 2014 |
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Website | https://www.dolby.com/technologies/dolby-vision/ |
Dolby Vision is a set of technologies developed by Dolby Laboratories for high dynamic range (HDR) video. [1] [2] [3] It covers content creation, distribution, and playback. [1] [4] [5] [6] 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, [1] [7] making it the first available HDR format. HDR10+ is a competitor HDR format that also uses dynamic metadata. [8]
Dolby Vision IQ is an update designed to optimize Dolby Vision content according to the ambient light. [9]
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. [10]
Dolby Vision allows for a maximum resolution of 8K, up to 12-bit color depth, and maximum peak brightness of 10,000 nits. [11] 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. [12]
Dolby Vision includes the PQ transfer function, a wide-gamut color space (ITU-R Rec. BT.2020 in YCBCR 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. [13]
This dynamic metadata allows adjusting of the image on a scene-by-scene or even frame-by-frame basis. [14] 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. [15]
The Dolby Vision format is capable of representing videos with a peak brightness up to 10,000 cd/m2 and a color gamut up to Rec. 2020. [16] 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: [17]
Dolby Vision metadata include: [15]
Dolby Vision 4.0 introduces new secondary trims for hue and saturation adjustment. [18]
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 | SDR | |
10 | 10-bit AV1 | None or HDR10 or SDR or HLG | |
20 | 10bit MV-HEVC for 3D or HEVC for 2D | None (It uses proprietary IPTPQc2) |
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 |
Some Dolby Vision profiles are dual layer (for example: the profile 7 used for Ultra HD Blu-ray). [20] The base layer (BL) and the enhancement layer (EL) are combined to produce a 12-bit video stream. [4]
The enhancement layer can be full enhancement layer (FEL) or minimum enhancement layer (MEL). [20]
Dolby Vision is a proprietary solution by Dolby. [27]
In 2021, compatible color grading systems can create Dolby Vision automatic metadata with no additional cost for content creators. [27] A $2,500 annual license is required to activate the trims allowing content creators to manually adjust the video. [27] OEM and manufacturer of a grading, mastering, editorial, or other professional application or device need to apply for a license. [27]
Dolby SVP of Business Giles Baker has stated that the royalty cost for Dolby Vision is less than $3 per TV. [28] [29] [30]
Despite the proprietary nature, several free software implementations of Dolby Vision exist (see § Software).
Dolby Laboratories, Inc. is a British-American technology corporation specializing in audio noise reduction, audio encoding/compression, spatial audio, and HDR imaging. Dolby licenses its technologies to consumer electronics manufacturers.
High-Definition Multimedia Interface (HDMI) is a proprietary audio/video interface for transmitting uncompressed video data and compressed or uncompressed digital audio data from an HDMI-compliant source device, such as a display controller, to a compatible computer monitor, video projector, digital television, or digital audio device. HDMI is a digital replacement for analog video standards.
High dynamic range (HDR), also known as wide dynamic range, extended dynamic range, or expanded dynamic range, is a signal with a higher dynamic range than usual.
8K resolution refers to an image or display resolution with a width of approximately 8,000 pixels. 8K UHD is the highest resolution defined in the Rec. 2020 (UHDTV) standard.
ITU-R Recommendation BT.2020, more commonly known by the abbreviations Rec. 2020 or BT.2020, defines various aspects of ultra-high-definition television (UHDTV) with standard dynamic range (SDR) and wide color gamut (WCG), including picture resolutions, frame rates with progressive scan, bit depths, color primaries, RGB and luma-chroma color representations, chroma subsamplings, and an opto-electronic transfer function. The first version of Rec. 2020 was posted on the International Telecommunication Union (ITU) website on August 23, 2012, and two further editions have been published since then.
FreeSync is an adaptive synchronization technology that allows LCD and OLED displays to support a variable refresh rate aimed at avoiding tearing and reducing stuttering caused by misalignment between the screen's refresh rate and the content's frame rate.
Ultra HD Blu-ray is a digital optical disc data storage format that is an enhanced variant of Blu-ray. Ultra HD Blu-ray supports 4K UHD video at frame rates up to 60 progressive frames per second, encoded using High-Efficiency Video Coding. These discs are incompatible with existing standard Blu-ray players.
The hybrid log–gamma (HLG) transfer function is a transfer function jointly developed by the BBC and NHK for high dynamic range (HDR) display. It is backward compatible with the transfer function of SDR. It was approved as ARIB STD-B67 by the Association of Radio Industries and Businesses (ARIB). It is also defined in ATSC 3.0, Digital Video Broadcasting (DVB) UHD-1 Phase 2, and International Telecommunication Union (ITU) Rec. 2100.
HDR10 Media Profile, more commonly known as HDR10, is an open high-dynamic-range video (HDR) standard announced on August 27, 2015, by the Consumer Electronics Association. It is the most widespread HDR format.
DCI-P3 is a color space defined in 2005 as part of the Digital Cinema Initiative, for use in theatrical digital motion picture distribution (DCDM). Display P3 is a variant developed by Apple Inc. for wide-gamut displays.
Standard-dynamic-range video is a video technology which represents light intensity based on the brightness, contrast and color characteristics and limitations of a cathode ray tube (CRT) display. SDR video is able to represent a video or picture's colors with a maximum luminance around 100 cd/m2, a black level around 0.1 cd/m2 and Rec.709 / sRGB color gamut. It uses the gamma curve as its electro-optical transfer function.
Ultra HD Forum is an organization whose goal is to help solve the real world hurdles in deploying Ultra HD video and thus to help promote UHD deployment. The Ultra HD Forum will help navigate amongst the standards related to high dynamic range (HDR), high frame rate (HFR), next generation audio (NGA), and wide color gamut (WCG). The Ultra HD Forum is an industry organisation that is complementary to the UHD Alliance, covering different aspects of the UHD ecosystem.
ITU-R Recommendation BT.2100, more commonly known by the abbreviations Rec. 2100 or BT.2100, introduced high-dynamic-range television (HDR-TV) by recommending the use of the perceptual quantizer or hybrid log–gamma (HLG) transfer functions instead of the traditional "gamma" previously used for SDR-TV.
The perceptual quantizer (PQ), published by SMPTE as SMPTE ST 2084, is a transfer function that allows for HDR display by replacing the gamma curve used in SDR. It is capable of representing luminance level up to 10000 cd/m2 (nits) and down to 0.0001 nits. It was developed by Dolby and standardized in 2014 by SMPTE and also in 2016 by ITU in Rec. 2100. ITU specifies the use of PQ or HLG as transfer functions for HDR-TV. PQ is the basis of HDR video formats and is also used for HDR still picture formats. PQ is not backward compatible with the BT.1886 EOTF, while HLG is compatible.
High-dynamic-range television (HDR-TV) is a technology that uses high dynamic range (HDR) to improve the quality of display signals. It is contrasted with the retroactively-named standard dynamic range (SDR). HDR changes the way the luminance and colors of videos and images are represented in the signal, and allows brighter and more detailed highlight representation, darker and more detailed shadows, and more intense colors.
The Apple TV app is a line of media player software programs developed by Apple Inc. for viewing television shows and films delivered by Apple to consumer electronic devices. It can stream content from the iTunes Store, the Apple TV Channels a la carte video on demand service, and the Apple TV+ original content subscription service. On iPhone, iPad, iPod Touch, Vision Pro, and Apple TV devices it can also index and access content from linked apps of other video on demand services.
JPEG XT is an image compression standard which specifies backward-compatible extensions of the base JPEG standard.
HDR10+ is a high dynamic range (HDR) video technology that adds dynamic metadata to HDR10 source files. The dynamic metadata are used to adjust and optimize each frame of the HDR video to the consumer display's capabilities in a way based on the content creator's intentions.
The third-generation iPhone SE is a smartphone designed and developed by Apple Inc. It is part of the 15th generation of the iPhone, alongside the iPhone 13 and 13 Mini and iPhone 13 Pro and 13 Pro Max models. Apple announced the third-generation iPhone SE on March 8, 2022, as the successor to the second-generation iPhone SE of 2020. Pre-orders began on March 11, 2022, and the phone was released afterwards on March 18, 2022. It was released with a starting price of US$429, a $30 increase over its predecessor.
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