Container format is the way digital information is stored on a computer system. The two main media formats are multimedia container formats and single coding formats. Computer systems use container formats to decode files so users are able to see the data stored in a particular file. This applies to audio and video files. The first generic container format was called interchange file format, or IFF.
Multimedia container formats contain audio codecs which is a coding and decoding software. Codec is used during the formatting process to modify the audio portion of digital data files for the most efficient storage. Audio codec is also programmed to coordinate with video files so they are synchronized when viewed. The most common types of container format are 3GPP, ASF, and AVI.
Third generation partnership project, or 3GPP, is a container format used primarily in mobile phones. 3GPP is a collaborative effort between the European Telecommunications Standard Institute, the China Communications Standards Association, the Telecommunications Technology Association, and the Alliance for Telecommunications Industry Solutions. This multi-country collaboration provides global access and consistent format for video playback and recording on mobile phones.
Advanced systems format, or ASF, is a container format used most often with Microsoft based computer systems. The output files are either Windows Media Audio (WMA) or Windows Media Video (WMV). In addition to just the video and audio portion, ASF container format files also contain information such as the artist, title and name of the album. This is especially helpful when playing from a programmed song list because the information is available on screen.
Audio video interweave, or AVI, is another Microsoft based container format. Similar to a DVD, an AVI file plays both audio and video simultaneously. AVI is a subset of resource interchange file format (RIFF). The AVI files are small parts of audio and video file that are formatted in RIFF style. The combined AVI files are strung together to form the audio and video portions of the movie being played.
Single coding container formats include both the storage and coding. Once the file is opened the coding can be modified while the storage remains the same. Examples of a single coding container format include portable network graphics (PNG) and joint photographic experts group (JPG) network graphics (JNG). JPEG is the most common way digital photographs are stored that allows the image to be compressed so it can be saved to a computer system without using a significant amount of storage space.