Daala

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Daala
Incorrectly coded image with colored errors that is used instead of a logo


Incorrectly coded image with colored errors that is used instead of a logo

File extension : .ogv
MIME type : video / ogg
Developed by: Xiph.Org , Mozilla , IETF
Type: Video format , lossy video data compression
Contained in: Ogg
Website : xiph.org/daala


Incorrectly coded image with colored errors that is used instead of a logo

Daala is an open data format under development for lossy video compression . It is being developed under the direction of Timothy B. Terriberry of the Xiph.Org Foundation and main sponsor Mozilla . Engineers from Google Inc. and Cisco Systems are among three dozen other contributors outside of these organizations . Technologies from Daala and Opus are now being incorporated into AV1 .

The name is taken from the female fantasy character Admiral Natasi Daala from Star Wars .

The reference implementation is written in C and is published as free software including source code under the terms of a BSD-like license .

Software patents are registered for technologies used and developed in Daala and made freely available for general use. However, their use to defend against patent lawsuits by third parties is reserved.

Since June 20, 2013, the development has been accompanied by a series of irregularly published articles on the underlying technology on the website of the Xiph.Org Foundation. Project participants also give lectures at various IT conferences.

Design goals

It should be suitable as a future standard for use on the Internet and for real-time applications. For this, it should be openly documented and usable free of software data restrictions so that it can spread as freely as possible. Furthermore, it should be suitable for a wide range of usage scenarios.

A performance comparable or better than that of other modern methods is sought. For reasons of patent law, the developers rely less on the incremental further development of proven design patterns. Instead, riskier investments in finding and testing basic coding techniques should yield more new and potentially more rewarding approaches. This is intended to break through the ever increasing increase in the coding effort with further improvements, which is evident in the development of other methods. All previous methods in use have shared the same basic design for two decades ( H.261 ).

In addition, options for parallel processing should be considered and hardware support should be sought.

It is intended as a highly efficient video format for similar applications such as High Efficiency Video Coding (HEVC or H.265) and VP9 . Its performance is declared to be aimed at a generation after HEVC and VP9.

technology

An unconventional cosine transform with overlapping blocks is used as a basic technique. Compared to other video codecs that use the discrete cosine transformation (DCT) directly, this reduces the occurrence of block artifacts without having to implement additional filter measures against block artifacts.

For quantization, Daala uses perceptual vector quantization ( PVQ , a spherical vector quantization ), which is based on human perception . Chrominance components are predicted from the luminance component. A conditional replacement filter similar to a median and a bilateral filter is used as an in-loop filter against ringing artifacts.

The output data of the encoder are packed into a single bit stream with area coding .

history

Within the family of Xiph-Org multimedia formats, Daala is the successor to the Theora format, which was completed in 2004 . The problems with the agreement on codecs for WebRTC and the successes in the development of the audio coding standard Opus are named as the main motivations for the development of a video coding standard . Following on from the success of the Opus project of the Internet Engineering Task Force (IETF), a global standard is also to be developed there from Daala. The purpose of Daala is to be an initial template for the development of this standard. It is, therefore, hoped that it will be reshaped or absorbed by many useful contributions from other parties.

The first experimental code already existed in 2010. As of May 27, 2013, the first steps should be taken from a pure research project to a functioning codec prototype. Then on May 30th, video was streamed through the Internet with an alpha prototype .

After several preliminary meetings since October 1, 2014, a corresponding working group of the IETF officially became active on May 18, 2015. Among other things, a number of coding techniques from Daala were presented as a working basis.

In June 2016, Daala ( according to the algorithmic metric PSNR-HVS-M ) had almost the same bit rate efficiency as HEVC.

NetVC

The Internet Engineering Task Force (IETF) has set up a working group that is tasked with developing an “Internet Video Codec” (“NetVC”). As part of the working group, other partners are now also involved in the further development of Daala. For example, technology is now being integrated that was brought in by Cisco Systems, which was also involved in the development of HEVC. Both Daala and the Thor codec presented by Cisco are to be incorporated into NetVC.

Some of the preliminary design requirements for NetVC are support for 8 to 12 bits per sample color depth , support for resolutions up to 4K , support for 4: 2: 0, 4: 2: 2, and 4: 4: 4 color subsampling , Support for the color spaces Rec. 709 and Rec. 2020 and consideration for parallel processing. Additional features that could be added to NetVC depending on the complexity are lossless compression, RGB color mode and alpha channels .

literature

  • Henrique S. Malvar: Extended lapped transforms: properties, applications, and fast algorithms . In: IEEE Transactions on Signal Processing . tape 40 , no. 11 , 1992, pp. 2703-2714 , doi : 10.1109 / 78.165657 ( microsoft.com [PDF]).
  • Trac D. Tran, Jie Liang, Chengjie Tu: Lapped transform via time-domain pre- and post-filtering . In: IEEE Transactions on Signal Processing . tape 51 , no. 6 , 2003, p. 1557–1571 , doi : 10.1109 / TSP.2003.811222 ( thanglong.ece.jhu.edu [PDF]).

Web links

Individual evidence

  1. ↑ Janko Roettgers: Open codec pioneer leaves Red Hat, joins Mozilla to work on next-generation video codec . In: GigaOm . October 15, 2013. Retrieved April 20, 2014.
  2. ↑ Sebastian Grüner: Free video codec: Daala must patent technology , golem.de, February 1, 2015
  3. ^ A b Christopher Montgomery : Introducing Daala , Xiph . Org Foundation . June 20, 2013. Accessed June 21, 2013.  
  4. ^ TD Tran, Jie Liang, Chengjie Tu: Lapped transform via time-domain pre- and post-filtering . In: IEEE Transactions on Signal Processing . tape 51 , no. 6 , June 2003, p. 1557–1571 , doi : 10.1109 / TSP.2003.811222 ( thanglong.ece.jhu.edu [PDF]). Lapped transform via time-domain pre- and post-filtering ( memento of the original from March 4, 2016 in the Internet Archive ) 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.  @1@ 2Template: Webachiv / IABot / thanglong.ece.jhu.edu
  5. ↑ Extended Lapped Transforms: Properties, Applications, and Fast Algorithms , Henrique S. Malvar, Dept. of Electrical Engineering, Universidade de Brasília. in: IEEE Trans. on Signal Processing. Volume 40, No. 11, pp. 2703-2714, November 1992 (PDF).
  6. ↑ a b Lucian Armasu: IETF Begins Standardization Process For Next-Generation 'NETVC' Video Codec (Daala) , Tom's Hardware . March 25, 2015. Accessed March 28, 2015. 
  7. ↑ Rudi Schmidts: Daala - better than H.265 / HEVC and V9? , slashCAM, October 23, 2013
  8. ↑ Thomas Daede: Senior Honors Thesis - Daala in Hardware ( Memento of the original from March 20, 2015 in the Internet Archive ) 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. , November 25, 2013 @1@ 2Template: Webachiv / IABot / thomasdaede.com
  9. ↑ Stephen Shankland: VLC steps into next-gen video wars with VP9, ​​HEVC support . In: CNET . November 15, 2013. Retrieved April 20, 2014.
  10. ↑ Lucian Parfeni: Mozilla Announces Next-Generation Video Codec to Leapfrog Google's VP9 and H.265 . In: Softpedia . October 30, 2013. Retrieved April 20, 2014.
  11. ^ Nathan Willis: Developing the Opus and Daala codecs . In: LWN.net . October 30, 2013. Retrieved April 20, 2014.
  12. ↑ Thomas R. Fischer: A pyramid vector quantizer . In: IEEE (Ed.): IEEE Transactions on Information Theory . tape 32 , no. July 4 , 1986.
  13. ↑ Jean-Marc Valin: Revisiting Daala Technology Demos , June 6, 2016
  14. ^ Initial import of Timothy Terriberry's daala-exp code. In: github.com. GitHub, October 13, 2010, accessed August 1, 2015 .
  15. ^ Message from Timothy B. Terriberry dated May 20, 2013 on the IETF video-codec mailing list: Daala Coding Party
  16. ↑ Internet Video Codec (netvc) - History
  17. ↑ Draft documents of the NetVC working group
  18. ↑ Sebastian Grüner (golem.de), June 9, 2016: Free video codecs sometimes better than H.265
  19. ↑ NETVC Hackathon Results IETF 93 (Prague) (PDF)
  20. ↑ Sebastian Grüner: Video codec free of license fees: Make one out of three , golem.de, 23 September 2015
  21. ↑ a b J. Moffitt: video codec requirements , IETF. March 9, 2015. Accessed March 28, 2015.