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Dirac is a prototype algorithm for the encoding and decoding (see codec) of raw video. It was presented by the BBC in January 2004 as the basis of a new codec for the transmission of video over the Internet. Flowcharts are often used to represent algorithms. ...
A Codec is a device or program capable of performing encoding and decoding on a digital data stream or signal. ...
The British Broadcasting Corporation, invariably known as the BBC (and also informally known as the Beeb or Auntie) is the largest public broadcasting corporation in the world. ...
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 Codec is a device or program capable of performing encoding and decoding on a digital data stream or signal. ...
In communications, transmission is the act of transmitting electrical messages (and the associated phenonomena of radiant energy that pass through media). ...
Video is the technology of capturing, recording, processing, transmitting, and reconstructing moving pictures, typically using celluloid film, electronic signals, or digital media, primarily for viewing on television or computer monitors. ...
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 PAL 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. ...
The codec is named in honour of the British scientist Paul Dirac. The physicist Albert Einstein is probably the most famous scientist of our time. ...
Paul Adrien Maurice Dirac, OM, FRS (IPA: [dɪræk]) (August 8, 1902 – October 20, 1984) was a British theoretical physicist and a founder of the field of quantum physics. ...
Technology
Similar to common video codecs such as 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/MPEG-4 AVC or SMPTE's VC-1 (which is based on Microsoft's WMV 9), by employing wavelet compression, instead of the discrete cosine transforms used in older codecs. 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/MPEG-4 AVC and VC-1. MPEG-2 is the previous generation video codec used in the standard DVD format today. A Codec is a device or program capable of performing encoding and decoding on a digital data stream or signal. ...
The International Organization for Standardization (ISO) is an international standard-setting body composed of representatives from national standards bodies. ...
The International Electrotechnical Commission (IEC) is an international standards organization dealing with electrical, electronic and related technologies. ...
The Moving Picture Experts Group or MPEG is a working group of ISO/IEC charged with the development of video and audio encoding standards. ...
MPEG-4 is a standard used primarily to compress audio and video (AV) digital data. ...
The Microsoft Corporation, commonly known as just Microsoft, (NASDAQ: MSFT, HKSE: 4338) is a multinational computer technology corporation with global annual sales of US$44. ...
CIF (Common Intermediate Format) is used to standardize the horizontal and vertical resolutions in pixels of YUV sequences in video signals. ...
High-definition television (HDTV) means broadcast of television signals with a higher resolution than traditional formats (NTSC, SECAM, PAL) allow. ...
H.264, MPEG-4 Part 10, or AVC, for Advanced Video Coding, is a digital video codec standard which is noted for achieving very high data compression. ...
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 informal name of the SMPTE 421M video codec standard. ...
Wavelet compression is a form of data compression well suited for image compression (sometimes also video compression and audio compression). ...
2-D DCT compared to the DFT The discrete cosine transform (DCT) is a Fourier-related transform similar to the discrete Fourier transform (DFT), but using only real numbers. ...
H.264, MPEG-4 Part 10, or AVC, for Advanced Video Coding, is a digital video codec standard which is noted for achieving very high data compression. ...
VC-1 is the informal name of the SMPTE 421M video codec standard. ...
MPEG-2 is the designation for a group of coding and compression standards for Audio and Video (AV), agreed upon by MPEG (Moving Picture Experts Group), and published as the ISO/IEC 13818 international standard. ...
DVD (also known as Digital Versatile Disc or Digital Video Disc) is an optical disc storage media format that can be used for data storage, including movies with high video and sound quality. ...
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 lossy audio compression codec project headed by 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/MPEG-4 AVC is often as good or better in compression capability for still images,[citation needed] 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, MPEG-4 Part 10, or AVC, for Advanced Video Coding, is a digital video codec standard which is noted for achieving very high data compression. ...
Related projects The Schrödinger project aims to provide portable libraries, written in C, that implement the Dirac codec. It also hopes to allow embedding Dirac inside the Ogg container format. The project is named after Erwin Schrödinger. Wikibooks has a book on the topic of C Programming The C programming language (often, just C) is a general-purpose, procedural, imperative computer programming language developed in the early 1970s by Dennis Ritchie for use on the Unix operating system. ...
OGG can refer to several items: Ogg is a multimedia bitstream container, used for audio and video files, especially Vorbis audio files. ...
Erwin Schrödinger, as depicted on the former Austrian 1000 Schilling bank note. ...
License The experimental and unfinished Dirac codec, written in C++, was released under an Open Source license at SourceForge on 11 March 2004. C++ (generally pronounced /si plÊŒs plÊŒs/) is a general-purpose, high-level programming language with low-level facilities. ...
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. ...
March 11 is the 70th day of the year in the Gregorian Calendar (71st in Leap year). ...
2004 (MMIV) was a leap year starting on Thursday of the Gregorian calendar. ...
While the BBC owns some patents on Dirac, they have irrevocably granted a royalty-free license for their Dirac related patents to all of humanity. In addition, the BBC have checked (by extensive patent search) that Dirac doesn't infringe any third party patents, enabling the public to use Dirac for any imaginable purpose. The BBC releases Dirac under the Mozilla Public License, GPL, and LGPL. This may accelerate its adoption and lower entry costs into the emerging industry of Internet television. In computing, the Mozilla Public License is an open source and free software license. ...
The GNU logo For other uses of GPL, see GPL (disambiguation). ...
GNU logo The GNU Lesser General Public License (formerly the GNU Library General Public License) is an FSF approved Free Software license designed as a compromise between the GNU General Public License and simple permissive licenses such as the BSD license and the MIT License. ...
It has been suggested that IPTV be merged into this article or section. ...
See also It has been suggested that IPTV be merged into this article or section. ...
LiVES (LiVES is a Video Editing System) is a video editing program and VJ tool, released under GNU General Public License. ...
External links - Dirac project page
- Dirac project project page on SourceForge
- BBC Research and Development the Department (largely) working on the codec
- Schrödinger project
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