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Ogg
Ogg is a digital multimedia container format designed to provide for efficient streaming and manipulation of digital multimedia. It is maintained by the Xiph.Org Foundation and is free and open, unrestricted by software patents. Its name is derived from "ogging", jargon from the computer game ''Netrek''. The Ogg container format can multiplex a number of independent streams for audio, video, text (such as subtitles), and metadata. In the Ogg multimedia framework, Theora provides a lossy video layer. The audio layer is most commonly provided by the music-oriented Vorbis format or its successor Opus. Lossless audio compression formats include FLAC, and OggPCM. Until 2007, the .ogg filename extension was used for all files whose content used the Ogg container format. Since then, the Xiph.Org Foundation recommends that .ogg only be used for Ogg Vorbis audio files. Xiph.Org decided to create a new set of file extensions and media types to describe different types of content ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vorbis
Vorbis is a free and open-source software project headed by the Xiph.Org Foundation. The project produces an audio coding format and software reference encoder/decoder ( codec) for lossy audio compression, libvorbis. Vorbis is most commonly used in conjunction with the Ogg container format and it is therefore often referred to as Ogg Vorbis. Version 1.0 of Vorbis was released in May 2000. Since 2013, the Xiph.Org Foundation has stated that the use of Vorbis should be deprecated in favor of the Opus codec, an improved and more efficient format that has also been developed by Xiph.Org. Name Vorbis is named after the character Exquisitor Vorbis in the '' Discworld'' novel '' Small Gods'' by Terry Pratchett. The Ogg format is named after ''ogging'', jargon from the computer game '' Netrek''. Development Vorbis is a continuation of audio compression development started in 1993 by Chris Montgomery. Intensive development began following a September 1998 letter from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opus (audio Format)
Opus is a Lossy audio compression, lossy audio coding format developed by the Xiph.Org Foundation and standardized by the Internet Engineering Task Force, designed to efficiently speech coding, code speech and general audio in a single format, while remaining latency (audio), low-latency enough for real-time interactive communication and low-complexity enough for low-end embedded processors. Opus replaces both Vorbis and Speex for new applications. Opus combines the speech-oriented Linear predictive coding, LPC-based SILK algorithm and the lower-latency Modified discrete cosine transform, MDCT-based CELT algorithm, switching between or combining them as needed for maximal efficiency. Bitrate, audio bandwidth, complexity, and algorithm can all be adjusted seamlessly in each frame. Opus has the low algorithmic delay (26.5 ms by default) necessary for use as part of a real-time communication link, networked music performances, and live lip sync; by trading off quality or bitrat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xiph
The Xiph.Org Foundation is a nonprofit organization that produces free software, 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 codec designed to compete with the patented Windows Media Audio, WMA, MP3 and Advanced audio coding, AAC. As of 2013, development work was focused on Daala, an open and patent-free video format and codec designed to compete with VP9 and the patented High Efficiency Video Coding. In addition to its in-house development work, the foundation has also brought several already-existing but complementary free software projects under its aegis, most of which have a separate, active group of developers. These include Speex, an audio codec designed for speech, and Free Lossless Audio Codec, FLAC, a lossless audio codec. The Xiph.Org Foundation has criticized Microsoft and the Recording Industry Association of America, RIAA for their ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 container. The libtheora video codec is the reference implementation of the Theora video compression format developed by the Xiph.Org Foundation. Theora was derived from the formerly proprietary VP3 codec, released into the public domain by On2 Technologies. It is broadly comparable in design and bitrate efficiency to MPEG-4 Part 2, early versions of Windows Media Video, and RealVideo while it lacked some of the features present in some of these other codecs. It is comparable in open standards philosophy to the BBC's Dirac codec. Theora was named after Theora Jones, Edison Carter's Controller on the '' Max Headroom'' television program. Technical details Theora is a variable-bitrate, DCT-based video compression scheme. Like most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FLAC
FLAC (; Free Lossless Audio Codec) is an audio coding format for lossless compression of digital audio, developed by the Xiph.Org Foundation, and is also the name of the free software project producing the FLAC tools, the reference software package that includes a codec implementation. Digital audio compressed by FLAC's algorithm can typically be reduced to between 50 and 70 percent of its original size and decompresses to an identical copy of the original audio data. FLAC is an open format with royalty-free licensing and a reference implementation which is free software. FLAC supports metadata tagging, album cover art, and fast seeking. History Development was started in 2000 by Josh Coalson. The bitstream format was frozen with the release of version 0.9 of the reference implementation on 31 March 2001. Version 1.0 was released on 20 July 2001. On 29 January 2003, the Xiph.Org Foundation and the FLAC project announced the incorporation of FLAC under the Xiph.org banner. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Demultiplexer (media File)
A demultiplexer for digital media files, or media demultiplexer, also called a file splitter by laymen or consumer software providers, is software that demultiplexes individual elementary streams of a media file, ''e.g.'', audio, video, or subtitles and sends them to their respective decoders for actual decoding. Media demultiplexers are not decoders themselves, but are format container handlers that separate media streams from a (container) file and supply them to their respective audio, video, or subtitles decoders. Notable file splitters * Microsoft AVI splitter - Part of Microsoft Windows. * Haali Media Splitter - demultiplexes MP4 ( MPEG-4), M2TS ( MPEG transport stream) and MKV ( Matroska) files. * FLV Splitter - demultiplexes Flash video files. * Gabest splitter (part of Media Player Classic) - demultiplexes e.g. 3GP, MP4 * LAV Splitter - part of the LAV Filters project (open source DirectShow media splitter and decoders). * libavformat (part of the FFmpeg proj ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dirac (codec)
Dirac (and Dirac Pro, a subset standardised as SMPTE VC-2) is an open and royalty-free video compression format, specification and software video codec developed by BBC Research & Development. Dirac aimed to provide high-quality video compression for Ultra HDTV and competed with existing formats such as H.264. The specification was finalised in January 2008, and further developments were only bug fixes and constraints. In September of that year, version 1.0.0 of an I-frame only subset known as Dirac Pro was released and was standardised by the SMPTE as VC-2. Version 2.2.3 of the full Dirac specification, including motion compensation and inter-frame coding, was issued a few days later. Dirac Pro was used internally by the BBC to transmit HDTV pictures at the Beijing Olympics in 2008. Two open source and royalty-free video codec software implementations, libschrodinger and dirac-research, were developed. The format implementations were named in honour of the theoretical ph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Speex
{{More citations needed, date=May 2025 The Speex project is an attempt to create a free software speech codec, unencumbered by patent restrictions. Speex is licensed under the BSD License and is used with the Xiph.org Foundation's Ogg container format. The Speex coder uses the Ogg bitstream format, and the Speex designers see their project as complementary to the Vorbis general-purpose audio compression project. Description Unlike many other speech codecs, Speex is not targeted at cell phones but rather at voice over IP (VoIP) and file-based compression. The design goals have been to make a codec that would allow both very good quality speech and low bit rate, which led to the development of a codec with multiple bit rates. Very good quality also meant the support of wideband (16 kHz sampling rate) in addition to narrowband (telephone quality, 8 kHz sampling rate). Designing for VoIP instead of cell phone use means that Speex must be robust to lost packets, but not to cor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Audio Coding Format
An audio coding format (or sometimes audio compression format) is a content representation format for storage or transmission of digital audio (such as in digital television, digital radio and in audio and video files). Examples of audio coding formats include MP3, AAC, Vorbis, FLAC, and Opus. A specific software or hardware implementation capable of audio compression and decompression to/from a specific audio coding format is called an '' audio codec''; an example of an audio codec is LAME, which is one of several different codecs which implements encoding and decoding audio in the MP3 audio coding format in software. Some audio coding formats are documented by a detailed technical specification document known as an audio coding specification. Some such specifications are written and approved by standardization organizations as technical standards, and are thus known as an audio coding standard. The term "standard" is also sometimes used for ''de facto'' standards as wel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lossy
In information technology, lossy compression or irreversible compression is the class of data compression methods that uses inexact approximations and partial data discarding to represent the content. These techniques are used to reduce data size for storing, handling, and transmitting content. Higher degrees of approximation create coarser images as more details are removed. This is opposed to lossless data compression (reversible data compression) which does not degrade the data. The amount of data reduction possible using lossy compression is much higher than using lossless techniques. Well-designed lossy compression technology often reduces file sizes significantly before degradation is noticed by the end-user. Even when noticeable by the user, further data reduction may be desirable (e.g., for real-time communication or to reduce transmission times or storage needs). The most widely used lossy compression algorithm is the discrete cosine transform (DCT), first published by N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subtitles
Subtitles are texts representing the contents of the audio in a film, television show, opera or other audiovisual media. Subtitles might provide a transcription or translation of spoken dialogue. Although naming conventions can vary, captions are subtitles that include written descriptions of other elements of the audio, like music or sound effects. Captions are thus especially helpful to deaf or hard-of-hearing people. Subtitles may also add information that is not present in the audio. Localizing subtitles provide cultural context to viewers. For example, a subtitle could be used to explain to an audience unfamiliar with sake that it is a type of Japanese wine. Lastly, subtitles are sometimes used for humor, as in '' Annie Hall'', where subtitles show the characters' inner thoughts, which contradict what they were saying in the audio. Creating, delivering, and displaying subtitles is a complicated and multi-step endeavor. First, the text of the subtitles needs to be wri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
