3gp The 3GP file format and its associated filename extension .3gp is an audio, video, and text container developed by the 3rd generation partnership project. The target market for the 3gp file format is 3G enabled UMTS mobile phones through associated UMTS multimedia services. Though mobile devices operating on high speed networks are the intended hardware associated with playing .3gp files, many PC codec packs exist which grant compatibility for .3gp playback. The format has a basic profile in which files of this format do not reference any external media sources and support for audio, video, and text is limited to a single track.
avi The AVI file format is one of the most widely used multimedia containers ever devised. AVI, which stands for audio video interleaved, was first introduced to the public by Microsoft in 1992 as part of their 'video for windows' multimedia framework. Being a container format, an AVI file with the .avi filename extension can exist with both video and audio content synchronized for playback. The format can thus be used by authors to edit and encode audio video sequences or just video sequences. The Digital video AVI format exists in two forms, Type 1 and Type 2.