In video files used on computers, we can see the file extensions mp4, m4v, avi, mkv, vob and many others. mkv and avi are very commonly found terms among video files. In essence, these are just wrappings used to put together the contents; i.e. the audio and video files, inside. AVI format was developed by Microsoft in early 1990`s, and mkv was introduced in 2002.
AVI
AVI stands for Audio Video Interleave, which is a multimedia container format developed by Microsoft for windows operating system environment. AVI was developed from Resource Interchange File Format (RIFF), which is the previous proprietary format of Microsoft and IBM. AVI is designed for synchronous play of both audio and video files. AVI compress data or use uncompressed data encoding; therefore, the audio/video quality of the format is dependent on the compression. Often data is encoded with uncompressed or very low compression ratio. Therefore, an ordinary AVI file takes relatively higher storage space.
In AVI files, the media data is stored in chunks (common in all RIFF derivatives), where AVI file itself is a single chunk, which is further divided into two mandatory “chunks” and one optional “chunk”. The chunks hdrl and movi are mandatory and idx1 chunk is optional. Metadata can be stored in the info chunk of the file.
DV AVI is a compressed form of the AVI that enables the file format, so that it is compatible with the DV format. Since the development of the AVI, new features have been developed in digital video technology, and the structure of the AVI file format prevents incorporating these changes into the file format. Therefore, the popularity and usage of the file format has dropped.
MKV
MKV is a media container format, which is both open standard and free. It is named after the Russian nesting dolls and called Matroska Multimedia Container. It is given this name specifically because of the containers ability to hold any number of data streams within a single file. It is completely an open specification and open source platforms and software use and support it extensively.
MKV files can hold multiple media streams within the same file. For example, a movie can be encoded in MKV to contain audio tracks in two languages, in the same file. The required track can be selected when playing. The individual tracks of a media file are saved as individual data lines. Conceptually, it is similar to the MP4 and AVI file formats, and share the chunk based architecture. Because of this, it’s easier to edit and store multimedia files in MKV format. Also, MKV format allows storing highest amount of data possible in a single file, rather conveniently.
Many media players developed for windows and Mac platforms now support the MKV file format; if not, installing a generic codec like K-lite codec pack will enable the player to run MKV files.
MKV vs AVI
• Both MKV and AVI are containers for digital Audio and Video (different from encoding formats).
• MKV is an open container format while AVI is a proprietary container format developed by Microsoft.
• Both can use the commonly used codecs such as h.264 and A3C, but AVI has limitations for H.264/AVC. Therefore, HD content might not be available.
• AVI can only store a single video stream and a single audio stream while MKV can store several audio and video streams in the same file (container).