High dynamic range video

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High dynamic range video (HDR video) offers a wider dynamic range and color range than standard dynamic range video (SDR).

Conventional SDR uses a color depth of 8 bits, which corresponds to a dynamic range of around 6 f-stops (64: 1). HDR video uses a color depth of 10 bits and thus achieves a dynamic range of up to 17.6 f-stops (200,000: 1, on a corresponding output device with 2,000  cd / m² ).

history

In 1990, the first real-time HDR video recordings were made by combining two cameras with different exposure settings .

At the CES in early 2015, various manufacturers presented displays with HDR support for the first time. Since then, Amazon Video (HDR10), Apple (Dolby Vision), Vudu (Dolby Vision) and Netflix (HDR10 and Dolby Vision) have been offering selected content as HDR video. YouTube followed in November 2016.

technology

Currently (as of 2020) two different methods for the transmission of HDR video content compete against each other, both of which were certified for the Ultra HD Blu-ray format introduced in 2015 . To play back HDR10, Ultra HD televisions must have the HDMI 2.0a or DisplayPort 1.4 interface . With Dolby Vision, HDMI 1.4b is sufficient.

The Society of Motion Picture and Television Engineers (SMPTE) has brought together all technologies for dynamic HDR in document ST 2094-1 Core: Dynamic Metadata for Color Volume Transform - Core Components . These include Dolby Vision ST 2094-10, SL-HDR1 Philips ST 2094-20, Advanced HDR Technicolor ST 2094-30 and HDR10 + Samsung ST 2094-40. Dynamic HDR means that the metadata is used dynamically to determine image information such as the brightness for certain film scenes or even frame by frame.

HDR10

The HDR10 Media Profile , or HDR10 for short , is an extension of the video level dynamic with 10-bit color depth in the Rec. 2020 color space . As with previous 8-bit image information, the interpretation of the image information is carried out by the output device. Depending on the display settings and options, the displayed result can differ significantly from other output devices. SMPTE ST-2084 Perceptual Quantizer (PQ) sends the color calibration of the master display used as static metadata SMPTE ST-2086 to the output device. It is an open standard that is supported by a large number of manufacturers.

HLG

Hybrid Log Gamma (HLG) is an HDR format that was developed from a joint research project between the BBC and the Japanese broadcaster NHK. HLG is an HDR solution that is used in the broadcast sector. It combines standard dynamic range and high dynamic range videos into a feed that HLG-compatible televisions can decode and display, while non-compatible devices display a standard dynamic range (SDR) image.

HLG was added to the Sistema Brasileiro de Televisão Digital (SBTVD) in 2019 .

HDR10 +

HDR10 + , also known as HDR10 Plus , was announced in April 2017 by the South Korean consumer electronics company Samsung and the US on-demand video service provider Amazon Video . HDR10 + is a dynamic HDR technology based on the ST-2084 PQ curve invented by Dolby and defined by the SMPTE under the name ST 2094-40 . HDR10 + is an open standard that is license-free and can also be used in conjunction with the High Efficiency Video Coding (HEVC) standard . The first release in this format was the film Bad Times at the El Royale in early 2019 .

September 2017 it was announced that the US-American film production company 20th Century Fox and the Japanese electronics company Panasonic Corporation would support HDR10 +. At the beginning of January 2018, the participation of the US film company Warner Bros. Entertainment in Allianz was announced.

Dolby Vision

Dolby Vision logo

Dolby Vision supports the SMPTE ST-2084 Perceptual Quantizer (PQ) process, developed and standardized by them, and up to 12-bit color information. In practice, brightness information can be displayed with luminance levels of 10,000 cd / m². Master displays common today usually only achieve a maximum of 4,000 cd / m². A larger gamut range is made possible by ITU-R Rec. 2020. It also supports SMPTE ST 2086 and SMPTE ST 2094-10. The latter is able to transfer dynamic metadata to the output device. These can for example contain color calibrations depending on the scene, which results in a reproduction that is more faithful to the original. These dynamic metadata are summarized in an enhancement layer, in which two types are distinguished: MEL (M stands for minimal ) and FEL (F stands for full ). These two types differ in the amount of image information and the resulting size.

The maximum resolution with Dolby Vision is 7680 × 4320 pixels ( 8K ), the maximum refresh rate 120 fps. In the broadcast area, Dolby Vision is used together with HLG. The Dolby Vision metadata SMPTE ST 2094-10 is supplied in an HLG signal and is also downward compatible with the HDR standard of the HLG specification. At Dolby Vision, every television model series is technically measured precisely by skilled workers from Dolby before mass production using a pre-series model and all relevant data is stored in a chip on the television set. This data is used to calculate the optimal image, which is calculated using patented algorithms. Dolby Vision devices up to model year 2019 receive support up to algorithm version 2.9, from model year 2020 update to algorithm version 4.0 (except TV sets from LG model year 2019) . Algorithm version 4.0 brings improvements in the fine-tuning of the image, so that there are even more options for the colorist to adapt the image to the wishes of the director. In contrast to HDR10 +, Dolby Vision is not license-free for device manufacturers.

See also

Individual evidence

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  3. ↑ HDR AND DOLBY VISION - The temporary return of the thick TV. January 28, 2015, accessed October 24, 2017 .
  4. ↑ youtube.googleblog.com
  5. ↑ Grobi.TV: Dolby backwards compatible up to HDMI 1.4b. Retrieved May 10, 2016 .
  6. ↑ Rachel Cericola: What Makes a TV HDR Compatible? The CEA Sets Guidelines. Big Picture Big Sound, August 27, 2015, accessed September 21, 2015 .
  7. ^ Adrienne Maxwell: Dolby Vision vs. HDR10: What You Need to Know. hometheaterreview.com, May 2, 2016, accessed July 29, 2016 .
  8. ↑ David Katzmaier: Vizio upgrades TVs to work with both HDR formats (hands-on). CNET , August 10, 2016, accessed August 10, 2016 .
  9. ↑ Samsung and Amazon Video Deliver Next Generation HDR Video Experience with Updated Open Standard HDR10 + , Samsung . April 20, 2017. Archived from the original on June 13, 2017 Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. . Retrieved January 8, 2018. @1@ 2Template: Webachiv / IABot / news.samsung.com 
  10. ↑ Cho Mu-Hyun: Samsung, Amazon partner for HDR10 Plus , ZDNet . April 20, 2017. Retrieved January 8, 2018. 
  11. ^ John Archer: Samsung And Amazon Just Made The TV World Even More Confusing , Forbes . April 20, 2017. Retrieved January 8, 2018. 
  12. ^ SMPTE ST 2094 and Dynamic Metadata , Society of Motion Picture and Television Engineers . Retrieved January 8, 2018. 
  13. ↑ John Laposky: Samsung, Amazon Video Team To Deliver Updated Open Standard HDR10 + , Twice. April 20, 2017. Retrieved January 8, 2018. 
  14. ↑ Pradeep Ramachandran: x265 , MulticoreWare Inc dated September 17, 2017, accessed February 6, 2018
  15. ↑ From summer films in the dynamic HDR10 format at Amazon , heise.de on May 3, 2017, accessed on February 6, 2018
  16. ↑ https://heise.de/-4266258
  17. ↑ HDR10 + sets new image quality standards at IFA 2017 , Samsung . September 22, 2017. Retrieved January 8, 2018. 
  18. ↑ Official HDR10 + logo revealed - Warner jumps on the bandwagon! , 4kfilme.de from January 6, 2018, accessed on January 9, 2018
  19. ↑ Grobi.TV: Dolby ST-2084 standard. Retrieved May 10, 2016 .
  20. ^ Dolby Laboratories: Dolby Vision. (PDF) Accessed August 16, 2020 .
  21. ↑ SMPTE Standards Update: SMPTE ST 2094 and Dynamic Metadata. (PDF) Retrieved January 12, 2017 .
  22. ↑ Dolby Laboratories: Dolby Vision UHD Blu-ray Authoring Workflow Guide. (PDF) Accessed August 16, 2020 .
  23. ^ Dolby Laboratories: Dolby Vision Profiles and Levels. (PDF) Accessed August 16, 2020 .
  24. ↑ Grobi.TV: TV sets are calibrated at the factory. Retrieved May 10, 2016 .
  25. ↑ Dolby Laboratories: Dolby Vision Update 4.0 July 2020 (PDF) Retrieved August 16, 2020 .
  26. ^ Dolby Laboratories: Dolby Vision Color Grading Best Practices Guide. (PDF) Accessed August 16, 2020 .
  27. ^ Dolby Laboratories: Why content creators and producers should create Dolby Vision masters. (PDF) Accessed August 16, 2020 .