Ogg

4f67.6753 hex Oggs (ASCII)

Ogg is a container file format for multimedia files, so it can contain both audio, video and text data. Ogg was designed with the goal of a free and unrestricted by software patents alternative to proprietary formats to offer to store multimedia content efficiently and stream. The streaming capability is the key design feature: Everything is packed in an Ogg container, can be streamed without any additional adjustments. This differs Ogg formats that only in certain dialects are streaming capable either (such as Matroska ) or not at all are live streaming capable ( such as MP4). Ogg streams can thereby be combined and chained without the need for an adjustment of the individual streams is necessary.

The development of the container format, is directed from the Xiph.Org Foundation, which is also responsible for some codecs that compress the content in a Ogg container.

The most popular codec is the audio codec Vorbis, which often simplistic (or erroneously ) referred to as Ogg, although Ogg is actually only the container format for Vorbis - encoded content.

History

The development of container format began in 1993 under the name of " squish", but the injured trademarks. Hence, the name was replaced by an expression from the computer game Netrek which means as much as to ogg: "to do anything forcefully, Possibly without consideration of the drain on future resources" (such as: " address something very energetic, possibly without consideration of the other effects "). With the name of one of the main characters of the Discworld novels - the name Vorbis is from a Discworld character -, the witch Nanny Ogg, this naming had nothing to do according to the Xiph.Org Foundation.

In autumn 1998, Christopher Montgomery began with the development of the audio codec Vorbis, after the Fraunhofer Society had begun to enforce license fees for its popular MP3 format. The increasing diffusion of Vorbis Ogg container format which experienced an upswing. On 12 July 2002 Ogg has been released in version 1.0, which was intended as a stable version for end users. In May 2003, the definition was followed by RFCs: RFC 3533 defines the encapsulated data stream, while RFC 3534 Internet Media Type of Ogg files, application / ogg defined.

In September 2008 RFC 3534 has been replaced by RFC 5334. Here, the Internet Media Type application / ogg were redefined and the Internet Media type audio / ogg for audio data and video / ogg supplements for video data. Were as file name extensions. Ogx for application / ogg, ogv set. For video / ogg and. Oga. Ogg and. Spx for audio / ogg. The rarely even used media type application / x- ogg, however, comes from an earlier period than the official type was not specified. Not part of the Ogg specification is the ending. Ogm, this is part of the Ogg - related ( but not identical ) format Ogg Media, which split from Ogg to support additional video playback functions.

File Format

The Ogg file format is a container bitstream format. The containers contains data, which in turn are compressed with different codecs. When compressing most of the text codec Writ, the voice data codec Speex, the audio codec Vorbis or FLAC and Theora video codec to be used. These data (text, audio, video image so ) then, depending on their capacity, in logical bitstreams grouped. Each logical bitstream is thereby processed only with the right codec to it. In a container can be " stored " multiple logical bitstreams. Multiple logical bit streams of the same type may be included in a container ( for example, three logical video streams so ). This can interfere with playback also. For storage or transmission of data over the network, this logical bit streams are transferred to a physical bit-stream (so-called data flow). This is then sent over the network. On the receiver side, a decoder for this data stream regains the various logical streams ( ie, for example, text, audio, video) back.

Dissemination

Audio

Ogg has established itself in the IT field now, in the audio range Ogg Vorbis is supported by many software and hardware products. The main breakthrough in personal use was made ​​so far.

Video

In the video area Ogg Theora is not very common. But He delights in the open source scene increasing popularity. So there are, among others of the short films Big Buck Bunny (2008) and Sintel (2010 ) each Ogg versions. Both films were created exclusively with free software distributed under the Creative Commons name registration will license ( CC- BY).

High-definition video, the Matroska format is also free now but, increasingly, outside the open source scene through, so remains to be seen what role Ogg Theora will play in the future.

Brand Terms

The term Ogg was registered from 2001 for a time as a brand. During this time, a company could use, based in London, this brand according to information medium for warnings; so who the name Ogg example, used on a website, was be prompted by a warning to high cash payments. This type of brand management, however, has always violated German trademark law, therefore, had no legal relevance. December 31, 2011 ended the period of protection, the brand was not renewed and therefore out.

Criticism

A FFmpeg developers estimated in March 2010, the qualities of Ogg container format as critical a. Among other things, he argues that the file size overhead is at least eight times larger by 1 % compared to the ISO MP4 format, and also that Ogg is not suitable for applications that require low latency. As an alternative with better properties in this respect allegedly he recommends the Matroska container format.

The Ogg developers described the allegations as though for the most part irrelevant and wrong. Among other things, MP4 and Matroska are just as ill-suited for applications with short latencies such as Ogg, particularly because the MP4 container is not live streamable, and the other stream properties to achieve Ogg, one has an inherently higher proportion of administrative data accept. If Matroska should be streamed, increase the proportion there even over the Ogg container. In general, he accused the critics, for each single property each pick out a certain other container for comparison, forgetting that each container must be customized for specific applications and for forcibly could only be suboptimal in other instances.

18463
de