CinemaDNG

CinemaDNG is the result of an Adobe-led initiative to define an industry-wide open file format for digital cinema files.[1] CinemaDNG caters for sets of movie clips, each of which is a sequence of raw video images, accompanied by audio and metadata. CinemaDNG supports stereoscopic cameras and multiple audio channels. CinemaDNG specifies directory structures containing one or more video clips, and specifies requirements and constraints for the open format files, (DNG, TIFF, XMP, and/or MXF), within those directories, that contain the content of those clips.[2]

CinemaDNG is different from the Adobe DNG (Digital Negative) format that is primarily used as a raw image format for still cameras. However, each CinemaDNG image is encoded using that DNG image format. The image stream can then be stored in one of two formats: either as video essence using frame-based wrapping in an MXF file, or as a sequence of DNG image files in a specified file directory. Each clip uses just one of these formats, but the set of clips in a movie may use both.

Rationale

The purpose of CinemaDNG is to streamline workflows and help ensure easy archiving and exchange. There are several advantages from using raw image data for cinema, just as there are for still photography, but like the latter the presence of proprietary raw formats can inhibit the required integration. Movie development typically involves complicated workflows involving many stages and multiple suppliers of software and hardware components.[3] All of these indicate the desirability of using open formats.

The ability to store images either within an MXF wrapper or as a DNG-sequence, with the ability to transfer from one to the other, provides extra flexibility. An additional benefit of using DNG is that there can be interchange between a CinemaDNG workflow and a still camera workflow.[2] One use is to extract stills from a movie for publicity or other purposes.

The DNG images that Adobe provided in the short example of how to store a video clip as a sequence of DNG files,[4] (see "Tangible deliverables"), were taken with a Canon EOS 30D dSLR camera, (and converted to DNG), rather than with a more conventional movie camera. This shows how any boundaries between different types of photography are weak, and illustrates why such open formats are important for the workflows of the future.

Timeline

Signs of progress

CinemaDNG has become an accepted file format in its brief history:

Tangible deliverables

All of these are free and freely available;[4] however, at November 2009 the products are prerelease versions:

Standardization

There does not appear to be any commitment from Adobe (or any other company) to submit CinemaDNG to a standards body such as ISO. However, they have repeatedly emphasized that it will be an open format, and Adobe has stated "CinemaDNG uses fully-documented, vendor-neutral, standard formats for video and imaging – DNG, TIFF/EP, and MXF. The format is unencrypted and free from intellectual property encumbrances or license requirements".[28] It is reasonable to speculate that eventually CinemaDNG will become a formal standard, based on the history of DNG itself which has been submitted to ISO for use in the revision of ISO 12234-2 (TIFF/EP).

Rather than creating entirely new file formats, the strategy for CinemaDNG is primarily to specify how to package files and other data-sets, of existing open and/or standard formats, in consistent ways, so that not only can individual components of a movie be interchanged and archived, but so can sets of clips with all their associated video, audio, and metadata files.[2] The emphasis is on having a systematic structure that supports the very complicated workflows, involving many stages and suppliers and software and hardware components, of movie development.[3] The CinemaDNG specification is largely about this systematic directory structure and the requirements and constraints that ensure that individual files fit within it.

If CinemaDNG follows the same sort of path to standardization as DNG, (or indeed, PDF), there will first be a period while the specification is tested in the marketplace to ensure that it works in practise as well as theory. It will then be revised accordingly, so that whatever is standardized will be credible, well supported by products, and ready for immediate use.

In November 2014 Blackmagic Design introduced a proprietary extension to the CinemaDNG format in the form of a lossy compression scheme used in their URSA cameras.[29] These CinemaDNG files are only supported by Blackmagic Design's own DaVinci Resolve software.

See also

Digital Negative (DNG)

References

  1. 1 2 Adobe Press Release: Adobe Starts Initiative to Develop Open Format for Digital Cinema Files
  2. 1 2 3 4 Adobe Labs: CinemaDNG - Image Data Format Specification (Version 1.0.0.0) (PDF)
  3. 1 2 3 Adobe Labs: CinemaDNG Workflow - Using the CinemaDNG File Format in Cinema Workflows (PDF)
  4. 1 2 3 4 Adobe Labs Downloads: CinemaDNG
  5. ↑ Macworld: Adobe plans CinemaDNG format for cinema files
  6. ↑ electronista: Adobe plans CinemaDNG standard for cinema files
  7. ↑ IT Broadcast and Digital Camera: Raw Quality Key
  8. ↑ Adobe Labs: CinemaDNG
  9. ↑ ZDNet: Adobe offers CinemaDNG format for raw video
  10. ↑ Kopriva, Todd (28 September 2012). "CinemaDNG in After Effects CS6 (and elsewhere)". Adobe Systems.
  11. ↑ "Premier Pro CC". 8 August 2014.
  12. ↑ IRIDAS press release: IRIDAS Supports CinemaDNG RAW Standard
  13. ↑ Silicon Imaging press release: Silicon Imaging Oscar Filmmaking Digital Cinema Cameras go 3D
  14. ↑ Vision Research forum: Query about support for CinemaDNG
  15. ↑ RadiantGrid press release: RadiantGrid Technologies Launches v5.0 of the RadiantGrid Platform at IBC 2009
  16. ↑ Gamma & Density press release: 3cP - Cinematographer's Color Correction Program
  17. ↑ Press release in Forbes: ViewPLUS Introduces Lumiere 4K x 2K 60 FPS Digital Camera System
  18. ↑ ViewPLUS: Lumiere
  19. ↑ https://www.blackmagicdesign.com/press/pressdetails?releaseID=38121
  20. ↑ https://www.blackmagicdesign.com/press/pressdetails?releaseID=38108
  21. ↑ https://convergent-design.com/products/odyssey-raw/sony-fs700.html
  22. ↑ https://www.blackmagicdesign.com/press/pressdetails?releaseID=60307
  23. ↑ http://www.atomos.com/shogun/
  24. ↑ http://www.slimraw.com/
  25. ↑ http://www.dji.com/product/zenmuse-x5s/x5r
  26. ↑ http://www.fastcinemadng.com/
  27. ↑ Adobe Labs forum: CinemaDNG
  28. ↑ Adobe Labs: CinemaDNG File Format
  29. ↑ https://www.blackmagicdesign.com/press/release/20141120-01


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