Dirac is a prototype algorithm for the encoding and decoding (see codec) of raw video and sound. It was presented by the BBC in January 2004 as the basis of a new file format for the transmission of video over the Internet. Flowcharts are often used to represent algorithms. ... Codec is a portmanteau of either Compressor-Decompressor or Coder-Decoder, which describes a device or program capable of performing transformations on a data stream or signal. ... The British Broadcasting Corporation (BBC) was formed in 1927 by means of a royal charter. ... 2004 : January - February - March - April - May - June - July - August - September - October - November - December- → January 31, 2004 The United States defence budget is set to exceed US$400 billion next year—an almost 7% increase—according to budget proposals inadvertently posted on the Pentagons website. ... A file format is a particular way to encode information for storage in a computer file. ... In communications, transmission is the act of transmitting electrical messages (and the associated phenonomena of radiant energy that pass through media). ... Video (from Latin, I see) is the technology of processing electronic signals for representing moving pictures. ...

The codec is still not finished as a product, and thus regarded as still being under development. The immediate aim is to be able to decode standard digital TV definition (720 x 576i pixels per frame at 25 frames per second) in real time; the current version can decode about 17 frames per second on a 3 GHz PC but extensive optimisation is planned. 576i is the shorthand name for a video mode. ... Frame rate, or frame frequency, is the measurement of how quickly an imaging device can produce several consecutive images, called frames. ...

Similar to common video codecs such as the the ISO/IEC Moving Picture Experts Group (MPEG)'s MPEG-4 Part 2 or Microsoft's WMV 7, it can compress any size of picture from low-resolution QCIF (176x144 pixels) to HDTV (1920x1080) and beyond. However, it promises significant savings in bandwidth and improvements in quality over these codecs, by some claims even superior to those promised by the latest generation of codecs such as H.264/AVC (which is technically identical to MPEG's MPEG-4 Part 10) or SMPTE's VC-1 (which is based on Microsoft's WMV 9), by employing wavelet compression, replacing or augmenting the discrete cosine transforms used in older codecs with Wavelet transforms. Dirac's implementors make the preliminary claim of "a two-fold reduction in bit rate over MPEG-2 for high definition video"[1], an estimate which would put the design in about the same class of compression capability as the latest standardization efforts of H.264/AVC and VC-1. MPEG-2 is the previous generation video codec used in the standard DVD format today. Codec is a portmanteau of either Compressor-Decompressor or Coder-Decoder, which describes a device or program capable of performing transformations on a data stream or signal. ... Logo of the International Organization for Standardization The International Organization for Standardization (ISO or iso) is an international standard-setting body made up of representatives from national standards bodies. ... The International Electrotechnical Commission (IEC) is a standards organization dealing with electrical, electronic and related technologies. ... The Moving Picture Experts Group (MPEG) is a working group of ISO/IEC charged with the development of video and audio encoding standards. ... MPEG-4, introduced in late 1998, is the designation for a group of audio and video coding standards and related technology agreed upon by the ISO/IEC Moving Picture Experts Group (MPEG). ... Microsoft Corporation, (NASDAQ: MSFT) headquartered in Redmond, Washington, USA, was founded in 1975 by Bill Gates and Paul Allen. ... H.264 is a high compression digital video codec standard written by the ITU-T Video Coding Experts Group (VCEG) together with the ISO/IEC Moving Picture Experts Group (MPEG) as the product of a collective partnership effort known as the Joint Video Team (JVT). ... The Moving Picture Experts Group (MPEG) is a working group of ISO/IEC charged with the development of video and audio encoding standards. ... MPEG-4, introduced in late 1998, is the designation for a group of audio and video coding standards and related technology agreed upon by the ISO/IEC Moving Picture Experts Group (MPEG). ... The Society of Motion Picture and Television Engineers or SMPTE (pronounced simptee or sometimes sumptee) is a US professional association of engineers. ... VC-1 is the title of the SMPTE standardization effort of a video codec based on Microsoft Windows Media Video version 9. ... Wavelet compression is a form of data compression well suited for image compression (sometimes also video compression and audio compression). ... The discrete cosine transform (DCT) is a Fourier-related transform similar to the discrete Fourier transform (DFT), but using only real numbers. ... The wavelet transform is a transformation to basis functions that are localized in scale and in time as well (where the Fourier transform is only localized in frequency, never giving any information about where in space or time the frequency happens). ... H.264 is a high compression digital video codec standard written by the ITU-T Video Coding Experts Group (VCEG) together with the ISO/IEC Moving Picture Experts Group (MPEG) as the product of a collective partnership effort known as the Joint Video Team (JVT). ... VC-1 is the title of the SMPTE standardization effort of a video codec based on Microsoft Windows Media Video version 9. ... MPEG-2 (1994) is the designation for a group of audio and video coding standards agreed upon by MPEG (Moving Pictures Experts Group), and published as the ISO/IEC 13818 international standard. ...

Dirac is one of several projects attempting to apply wavelets to video compression. Others include Rududu [2] and Snow. Also of note is the Xiph.org Foundation's Tarkin, developed by the creators of the Vorbis audio codec, which offered impressive performance but saw only limited adoption. Tarkin showed much promise, but was put on hold so its creators could focus their efforts on Theora, a less experimental video codec based on On2 Technologies' VP3. Snow is an experimental lossy video codec developed by Michael Niedermayer for the FFmpeg package. ... The Xiph. ... Tarkin is an experimental lossy video codec formerly under development by the Xiph. ... Vorbis is an open and free audio compression (codec) project from the Xiph. ... Theora is a video codec being developed by the Xiph. ... VP3 was originally a proprietary video codec developed by On2 Technologies. ...

Wavelet compression is not merely experimental. It has already proven its viability in the JPEG 2000 compression standard for photographic images. However, it has not been shown to provide substantially superior compression capability than other techniques based on more traditional block-based coding. For example, H.264 is often as good or better in compression capability for still images, despite the wavelet-based design of JPEG-2000. The primary benefits of JPEG-2000 relative to other codecs are functionality aspects, such as scalability features, rather than compression capability. JPEG 2000 is a wavelet-based image compression standard. ... H.264 is a high compression digital video codec standard written by the ITU-T Video Coding Experts Group (VCEG) together with the ISO/IEC Moving Picture Experts Group (MPEG) as the product of a collective partnership effort known as the Joint Video Team (JVT). ...

The codec is named in honour of the British scientist Paul Dirac. This article is about the profession. ... Paul Adrien Maurice Dirac Paul Adrien Maurice Dirac, (August 8, 1902 – October 20, 1984) was a British theoretical physicist and a founder of the field of quantum physics. ...

Licence

The experimental and unfinished Dirac codec, written in C++, was released under an Open Source licence at SourceForge on 11 March 2004. C++ (pronounced see plus plus) is a general-purpose computer programming language. ... Open source refers to projects that are open to the public and which draw on other projects that are freely available to the general public. ... SourceForge is a collaborative software development management system. ... 11 March is the 70th day of the year in the Gregorian Calendar (71st in Leap year). ... 2004 is a leap year starting on Thursday of the Gregorian calendar. ...

While the BBC owns some patents on Dirac, they have irrevocably given royalty-free license of the Dirac related patents to all of humanity, enabling the public to utilize Dirac for any imaginable purpose. The BBC releases Dirac under the Mozilla Public License which also allows GPL and LGPL programs to use it. This may accelerate its adoption and lower entry costs into the emerging industry of Internet television. The Mozilla Public License is an open source and a free software license. ... // Origins Because of the increase in Internet connection speeds and the total number of people online, and the decrease in connection costs; it is increasingly common to find traditional television content, accessible freely and legally over the Internet. ...

See also

• Internet television

// Origins Because of the increase in Internet connection speeds and the total number of people online, and the decrease in connection costs; it is increasingly common to find traditional television content, accessible freely and legally over the Internet. ...

External links

• Dirac project page
• Dirac project project page on SourceForge
• BBC Research and Development the Department (largely) working on the codec