AVI file contains three parts: file header, data block and index block. The data block contains the actual data stream, that is, image and sound sequence data. This is the main body of the file and the main part that determines the file capacity. The size of a video file is equal to the data rate of the file multiplied by the length of playing the video, and the index block includes a list of data blocks and their positions in the file to provide random access to the data in the file. The file header includes general information of the file, data format definition, compression algorithm used and other parameters.

Extended data:

AVI information is mainly used for multimedia CD-ROM, which is used to save various image information such as TV and movies. It was introduced by Microsoft in 1992, and is known and familiar with people together with Windows3. 1. The so-called "audio and video interleaving" means that video and audio can be intertwined and played simultaneously.

The advantage of this video format is that it has good picture quality and can be used across multiple platforms. The disadvantage is that it is too large, and what is worse is that the compression standards are not uniform. The most common phenomenon is that the higher version of Windows media player can't play the AVI format video that was encoded and edited earlier.