Audio Video Interleave (AVI) is a way to digitally store multimedia audio and video content in a file for playback. The AVI format, introduced in the 1990s, is a built-in function of the Windows® operating system (operating system). AVI files use the file extension. Avi, and consists of a header tag followed by a series of information blocks. The AVI file format header provides details about the contents of the files, such as width, height and frame rate, while the information blocks store the actual audio and video data. An important advantage of the AVI format is that it can reproduce on most computers around the world.
Playing a multimedia file of any format, including AVI format, requires compatible software that understands the details of the file contents. If the correct software is not available to open and play a media file, the user will see a dialog box stating that Windows cannot open the file. Options are provided that allow the user to select the program from a list of available software or use the web to find the program. The AVI format generally eliminates the need to select a program.
In the years since the AVI format was created, many video techniques were introduced that were not designed when the AVI specification was defined. Also, the compression systems used to optimize space requirements when writing AVI files are not as effective as the techniques used in the most recently developed multimedia formats. As such, the AVI format requires about 5 megabytes (MB) of storage for each hour of video and does not support the ability to specify multimedia details such as aspect ratio, time codes or audio sample rate per under 32 kilohertz (kHz).
Many newer media file formats are making their way around the internet, including Ogg, MOV and NUT. Motion Picture Experts Group (MPEG), however, is becoming a standard and growing steadily in popularity. Software for creating and playing MPEG media files is included with Windows® and Mac operating systems
