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Wikipedia

Container format

January 13, 2023

This article is about a kind of computer file. For other uses, see container format (disambiguation).

A container format (informally, sometimes called a wrapper) or metafile is a file format that allows multiple data streams to be embedded into a single file, usually along with metadata for identifying and further detailing those streams.[1] Notable examples of container formats include archive files (such as the ZIP format) and formats used for multimedia playback (such as Matroska, MP4, and AVI). Among the earliest cross-platform container formats were Distinguished Encoding Rules and the 1985 Interchange File Format.

Design

 
The layouts of common container formats: AVI, Matroska and PDF (in German)

Although containers may identify how data or metadata is encoded, they do not actually provide instructions about how to decode that data. A program that can open a container must also use an appropriate codec to decode its contents. If the program doesn't have the required algorithm, it can't use the contained data. In these cases, programs usually emit an error message that complains of a missing codec, which users may be able to acquire.

Container formats can be made to wrap any kind of data. Though there are some examples of such file formats (e.g. Microsoft Windows's DLL files), most container formats are specialized for specific data requirements. For example, since audio and video streams can be coded and decoded with many different algorithms, a container format may be used to provide the appearance of a single file format to users of multimedia playback software.

Considerations

The differences between various container formats arise from five main issues:

  1. Popularity; how widely supported a container is.
  2. Overhead. This is the difference in file-size between two files with the same content in a different container.
  3. Support for advanced codec functionality. Older formats such as AVI do not support new codec features like B-frames, VBR audio or VFR video natively. The format may be "hacked" to add support, but this creates compatibility problems.
  4. Support for advanced content, such as chapters, subtitles, meta-tags, user-data.
  5. Support of streaming media.

Single coding formats

In addition to pure container formats, which specify only the wrapper but not the coding, a number of file formats specify both a storage layer and the coding, as part of modular design and forward compatibility.

Examples include JPEG File Interchange Format (JFIF) for containing JPEG data, and Portable Network Graphics (PNG).

In principle, coding can be changed while the storage layer is retained; for example, Multiple-image Network Graphics (MNG) uses the PNG container format but provides animation, while JPEG Network Graphics (JNG) puts JPEG encoded data in a PNG container; in both cases however, the different formats have different magic numbers – the format specifies the coding, though a MNG can contain both PNG-encoded images and JPEG-encoded images.

Multimedia container formats

Further information: Audio file format, Image file formats, and Video file format
See also: Comparison of video container formats

The container file is used to identify and interleave different data types. Simpler container formats can contain different types of audio formats, while more advanced container formats can support multiple audio and video streams, subtitles, chapter-information, and meta-data (tags) — along with the synchronization information needed to play back the various streams together. In most cases, the file header, most of the metadata and the synchro chunks are specified by the container format. For example, container formats exist for optimized, low-quality, internet video streaming which differs from high-quality Blu-ray streaming requirements.

Container format parts have various names: "chunks" as in RIFF and PNG, "atoms" in QuickTime/MP4, "packets" in MPEG-TS (from the communications term), and "segments" in JPEG. The main content of a chunk is called the "data" or "payload". Most container formats have chunks in sequence, each with a header, while TIFF instead stores offsets. Modular chunks make it easy to recover other chunks in case of file corruption or dropped frames or bit slip, while offsets result in framing errors in cases of bit slip.

Some containers are exclusive to audio:

Other containers are exclusive to still images:

Other flexible containers can hold many types of audio and video, as well as other media. The most popular multi-media containers are:

There are many other container formats, such as NUT, MXF, GXF, ratDVD, SVI, VOB and DivX Media Format

See also

References

  1. ^ Ho, Anthony T. S.; Li, Shujun (20 May 2016). Handbook of Digital Forensics of Multimedia Data and Devices, Enhanced E-Book. John Wiley & Sons. pp. 146–(?). ISBN 9781118757079. OCLC 953319457.

External links

  • Online Video File Format Identification Tool - Designed primarily for CCTV video formats and codecs

January 13, 2023
container, format, this, article, multiple, issues, please, help, improve, discuss, these, issues, talk, page, learn, when, remove, these, template, messages, this, article, incomprehensible, very, hard, understand, please, help, rewording, intended, meaning, . This article has multiple issues Please help improve it or discuss these issues on the talk page Learn how and when to remove these template messages This article may be incomprehensible or very hard to understand Please help by rewording it if the intended meaning can be determined The talk page may have details November 2018 This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Container format news newspapers books scholar JSTOR June 2017 Learn how and when to remove this template message Learn how and when to remove this template message This article is about a kind of computer file For other uses see container format disambiguation A container format informally sometimes called a wrapper or metafile is a file format that allows multiple data streams to be embedded into a single file usually along with metadata for identifying and further detailing those streams 1 Notable examples of container formats include archive files such as the ZIP format and formats used for multimedia playback such as Matroska MP4 and AVI Among the earliest cross platform container formats were Distinguished Encoding Rules and the 1985 Interchange File Format Contents 1 Design 1 1 Considerations 1 2 Single coding formats 2 Multimedia container formats 3 See also 4 References 5 External linksDesign Edit The layouts of common container formats AVI Matroska and PDF in German Although containers may identify how data or metadata is encoded they do not actually provide instructions about how to decode that data A program that can open a container must also use an appropriate codec to decode its contents If the program doesn t have the required algorithm it can t use the contained data In these cases programs usually emit an error message that complains of a missing codec which users may be able to acquire Container formats can be made to wrap any kind of data Though there are some examples of such file formats e g Microsoft Windows s DLL files most container formats are specialized for specific data requirements For example since audio and video streams can be coded and decoded with many different algorithms a container format may be used to provide the appearance of a single file format to users of multimedia playback software Considerations Edit This section possibly contains original research Please improve it by verifying the claims made and adding inline citations Statements consisting only of original research should be removed January 2011 Learn how and when to remove this template message The differences between various container formats arise from five main issues Popularity how widely supported a container is Overhead This is the difference in file size between two files with the same content in a different container Support for advanced codec functionality Older formats such as AVI do not support new codec features like B frames VBR audio or VFR video natively The format may be hacked to add support but this creates compatibility problems Support for advanced content such as chapters subtitles meta tags user data Support of streaming media Single coding formats Edit In addition to pure container formats which specify only the wrapper but not the coding a number of file formats specify both a storage layer and the coding as part of modular design and forward compatibility Examples include JPEG File Interchange Format JFIF for containing JPEG data and Portable Network Graphics PNG In principle coding can be changed while the storage layer is retained for example Multiple image Network Graphics MNG uses the PNG container format but provides animation while JPEG Network Graphics JNG puts JPEG encoded data in a PNG container in both cases however the different formats have different magic numbers the format specifies the coding though a MNG can contain both PNG encoded images and JPEG encoded images Multimedia container formats EditFurther information Audio file format Image file formats and Video file format See also Comparison of video container formats The container file is used to identify and interleave different data types Simpler container formats can contain different types of audio formats while more advanced container formats can support multiple audio and video streams subtitles chapter information and meta data tags along with the synchronization information needed to play back the various streams together In most cases the file header most of the metadata and the synchro chunks are specified by the container format For example container formats exist for optimized low quality internet video streaming which differs from high quality Blu ray streaming requirements Container format parts have various names chunks as in RIFF and PNG atoms in QuickTime MP4 packets in MPEG TS from the communications term and segments in JPEG The main content of a chunk is called the data or payload Most container formats have chunks in sequence each with a header while TIFF instead stores offsets Modular chunks make it easy to recover other chunks in case of file corruption or dropped frames or bit slip while offsets result in framing errors in cases of bit slip Some containers are exclusive to audio AIFF IFF file format widely used on Mac OS platform WAV RIFF file format widely used on Windows platform XMF Extensible Music Format Other containers are exclusive to still images FITS Flexible Image Transport System still images raw data and associated metadata TIFF Tagged Image File Format still images and associated metadata Macintosh PICT resource PICT superseded by PDF in Mac OS X Windows Metafile WMF EMF Enhanced Metafile Encapsulated PostScript EPS Computer Graphics Metafile CGM Portable Document Format PDF Corel Draw File CDR Scalable Vector Graphics SVG Rich Text Format file RTF Other flexible containers can hold many types of audio and video as well as other media The most popular multi media containers are 3GP used by many mobile phones based on the ISO base media file format ASF container for Microsoft WMA and WMV which today usually do not use a container AVI the standard Microsoft Windows container also based on RIFF DVR MS Microsoft Digital Video Recording proprietary video container format developed by Microsoft based on ASF Flash Video FLV F4V container for video and audio from Adobe Systems IFF first platform independent container format Matroska MKV not limited to any coding format as it can hold virtually anything it is an open standard container format MJ2 Motion JPEG 2000 file format based on the ISO base media file format which is defined in MPEG 4 Part 12 and JPEG 2000 Part 12 QuickTime File Format standard QuickTime video container from Apple Inc MPEG program stream standard container for MPEG 1 and MPEG 2 elementary streams on reasonably reliable media such as disks used also on DVD Video discs MPEG 2 transport stream a k a MPEG TS standard container for digital broadcasting and for transportation over unreliable media used also on Blu ray Disc video typically contains multiple video and audio streams and an electronic program guide MP4 standard audio and video container for the MPEG 4 multimedia portfolio based on the ISO base media file format defined in MPEG 4 Part 12 and JPEG 2000 Part 12 which in turn was based on the QuickTime file format Ogg standard container for Xiph org audio formats Vorbis and Opus and video format Theora RM RealMedia standard container for RealVideo and RealAudio WebM subset of Matroska used for web based media distribution on online platforms container for royalty free audio formats Vorbis Opus and video formats VP8 VP9 AV1 There are many other container formats such as NUT MXF GXF ratDVD SVI VOB and DivX Media FormatSee also EditArchive format Comparison of audio coding formats Comparison of video codecs Comparison of video container formats NTFS Metafiles List of codecs List of open source codecs SerializationReferences Edit Ho Anthony T S Li Shujun 20 May 2016 Handbook of Digital Forensics of Multimedia Data and Devices Enhanced E Book John Wiley amp Sons pp 146 ISBN 9781118757079 OCLC 953319457 External links EditOnline Video File Format Identification Tool Designed primarily for CCTV video formats and codecs Retrieved from https en wikipedia org w index php title Container format amp oldid 1120054340, wikipedia, wiki, book, books, library,

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