Daala is a

video coding format A video coding format (or sometimes video compression format) is a content representation format of digital video content, such as in a data file or bitstream. It typically uses a standardized video compression algorithm, most commonly based on ...

under development by the

Xiph.Org Foundation The Xiph.Org Foundation is a nonprofit organization that produces free multimedia formats and software tools. It focuses on the Ogg family of formats, the most successful of which has been Vorbis, an open and freely licensed audio format and ...

under the lead of Timothy B. Terriberry mainly sponsored by the

Mozilla Corporation The Mozilla Corporation is a wholly owned subsidiary of the Mozilla Foundation that coordinates and integrates the development of Internet-related applications such as the Firefox web browser, by a global community of open-source developers, s ...

. Like

Theora Theora is a free lossy video compression format. It was developed by the Xiph.Org Foundation and distributed without licensing fees alongside their other free and open media projects, including the Vorbis audio format and the Ogg contai ...

and

Opus Opus (: opera Opera is a form of History of theatre#European theatre, Western theatre in which music is a fundamental component and dramatic roles are taken by Singing, singers. Such a "work" (the literal translation of the Italian word "opera ...

, Daala is available free of any royalties and its reference implementation is being developed as

free and open-source software Free and open-source software (FOSS) is software available under a license that grants users the right to use, modify, and distribute the software modified or not to everyone free of charge. FOSS is an inclusive umbrella term encompassing free ...

. The name is taken from the fictional character of Admiral Natasi Daala from the ''

Star Wars ''Star Wars'' is an American epic film, epic space opera media franchise created by George Lucas, which began with the Star Wars (film), eponymous 1977 film and Cultural impact of Star Wars, quickly became a worldwide popular culture, pop cu ...

'' universe. The

reference implementation In the software development process, a reference implementation (or, less frequently, sample implementation or model implementation) is a program that implements all requirements from a corresponding specification. The reference implementation ...

is written in C and published, together with its

source code In computing, source code, or simply code or source, is a plain text computer program written in a programming language. A programmer writes the human readable source code to control the behavior of a computer. Since a computer, at base, only ...

, as

free software Free software, libre software, libreware sometimes known as freedom-respecting software is computer software distributed open-source license, under terms that allow users to run the software for any purpose as well as to study, change, distribut ...

under the terms of a BSD-like license.

Software patent A software patent is a patent on a piece of software, such as a computer program, library, user interface, or algorithm. The validity of these patents can be difficult to evaluate, as software is often at once a product of engineering, something ...

s are being filed for techniques used in and developed for Daala. Those patents are freely licensed to everybody to use for any purpose. However, the patent holders reserve the right to use them to counter patent infringement lawsuits filed by others. Since June 20, 2013, the development is accompanied by a series of sporadically published posts on the underlying technology on the website of the Xiph.Org Foundation. The Daala project is one of the collaborators in the

IETF The Internet Engineering Task Force (IETF) is a standards organization for the Internet standard, Internet and is responsible for the technical standards that make up the Internet protocol suite (TCP/IP). It has no formal membership roster ...

NETVC NETVC was the name given to a planned royalty-free video codec that was intended to be developed in the former Internet Video Codec working group of the IETF. It was intended to provide a royalty-free alternative to industry standards such as H.2 ...

project.

Design goals

Daala is aimed to be a suitable proposal for a new video coding standard for the

Internet The Internet (or internet) is the Global network, global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a internetworking, network of networks ...

and real-time applications. Therefore, it is meant to be usable free from patent licensing constraints and to be openly documented to enable widespread adoption. Also, it is being designed to cover a broad spectrum of use cases. Daala was projected to eventually perform as well as if not better than other modern formats. The developers want to rely less on improving traditional design principles incrementally as such effort is observed to deliver decreasing returns after many years, and tends to grow complexity. (All widely adopted designs to date share the same basic design that dates back to

H.261 H.261 is an ITU-T video compression standard, first ratified in November 1988. It is the first member of the H.26x family of video coding standards in the domain of the ITU-T Study Group 16 Video Coding Experts Group (VCEG, then Specialists Gr ...

from three decades ago.) Instead, the higher risk of researching and trying new basic techniques is expected to yield unprecedented and potentially more useful algorithms. Such an approach also makes software patent infringement less likely. Moreover, possibilities for parallel processing are considered and hardware support is being pursued. Daala is intended to be a high-efficiency video coding format for use cases similar to those of

High Efficiency Video Coding High Efficiency Video Coding (HEVC), also known as H.265 and MPEG-H Part 2, is a video compression standard designed as part of the MPEG-H project as a successor to the widely used Advanced Video Coding (AVC, H.264, or MPEG-4 Part 10). In compa ...

(HEVC or H.265) and VP9. It has been stated that the performance goal is to be a generation beyond HEVC and VP9.

Technology

As a basic technology Daala uses an unconventional discrete cosine transform with overlapping blocks. This reduces the blocking artifacts characteristic of other video codecs that use the

discrete cosine transform A discrete cosine transform (DCT) expresses a finite sequence of data points in terms of a sum of cosine functions oscillating at different frequency, frequencies. The DCT, first proposed by Nasir Ahmed (engineer), Nasir Ahmed in 1972, is a widely ...

(DCT) directly, without the need for additional filtering against blocking artifacts. The coefficients are coded by Perceptual Vector Quantisation (PVQ, a spherical

vector quantisation Vector quantization (VQ) is a classical quantization technique from signal processing that allows the modeling of probability density functions by the distribution of prototype vectors. Developed in the early 1980s by Robert M. Gray, it was orig ...

), which models human perception. All substreams that the encoder produces are coded to one bitstream by a range encoder.

History

Within the family of Xiph.Org multimedia formats, Daala is the successor to

from 2004. Problems with agreeing on video formats for

WebRTC WebRTC (Web Real-Time Communication) is a free and open-source project providing web browsers and mobile applications with real-time communication (RTC) via application programming interfaces (APIs). It allows audio and video communication and ...

and successes in the development of the audio coding standard

are being cited as motivations for developing a video coding standard. Following up on the successful standardisation of Opus at the

Internet Engineering Task Force The Internet Engineering Task Force (IETF) is a standards organization for the Internet standard, Internet and is responsible for the technical standards that make up the Internet protocol suite (TCP/IP). It has no formal membership roster ...

(IETF), it was planned to also develop a worldwide video coding standard there. The purpose of Daala is to provide an initial proposal for the development of that standard. Therefore, it is hoped to be transformed by or reassembled with a lot of useful contributions by other parties. First experimental code already existed in 2010. First steps in moving from merely investigating coding techniques to having a functional prototype were planned to start on May 27, 2013. On May 30 an

alpha Alpha (uppercase , lowercase ) is the first letter of the Greek alphabet. In the system of Greek numerals, it has a value of one. Alpha is derived from the Phoenician letter ''aleph'' , whose name comes from the West Semitic word for ' ...

prototype of Daala was used to

stream A stream is a continuous body of water, body of surface water Current (stream), flowing within the stream bed, bed and bank (geography), banks of a channel (geography), channel. Depending on its location or certain characteristics, a strea ...

video over the Internet. On September 17, 2014, it was generally stated that it could produce better results than its peers up to about 0.5 bits per pixel. According to Timothy Terriberry, another year of development is needed as of January 2015. After several preliminary meetings, a respective working group with the mission to develop an Internet Video Codec (NetVC) officially commenced activity on May 18, 2015. Among other contributions, a series of coding techniques from Daala were officially proposed to the group. On September 1, 2015, Mozilla announced that the

Alliance for Open Media The Alliance for Open Media (AOMedia) is a non-profit industry consortium headquartered in Wakefield, Massachusetts, and formed to develop open, royalty-free technology for multimedia delivery. It uses the ideas and principles of open web standa ...

would use elements of Daala to develop a royalty free video format,

AOMedia Video 1 AOMedia Video 1 (AV1) is an open, royalty-free video coding format initially designed for video transmissions over the Internet. It was developed as a successor to VP9 by the Alliance for Open Media (AOMedia), a consortium founded in 2015 tha ...

NETVC

On March 24, 2015, Daala was presented to the IETF as a candidate for their Internet Video Codec (

) video standard. Daala coding techniques have been proposed to the IETF for inclusion into NETVC.

References

* Monika Ermert, Volker Zota, March 25, 2015 (heise.de): /heise.de/-2584566 Lizenzfreier Videocodec Daala geht ins WebRTC-Rennen

External links

* {{Compression software Free video codecs Open formats Xiph.Org projects