3G2

3G2 is a multimedia container format defined by 3GPP2 for mobile devices. It is derived from the 3GP container used by 3GPP networks and is intended for storing and streaming video and audio on CDMA2000-based networks. Files typically use the .3g2 extension.

Technically, 3G2 is based on the ISO base media file format (MPEG-4 Part 12) and uses the same general file layout as MP4, with branding that identifies it as a 3G2 file. It can contain multiple tracks, including video, audio, and timed text, and is capable of streaming or progressive download.

Supported codecs include video such as H.263, MPEG-4 Part 2, and H.264, and audio such as AMR-NB, AMR-WB, and AAC. The exact codec support depends on the encoder and device. 3G2 was widely used on early 3G CDMA devices and remains supported by many modern players, though MP4 has largely supplanted it in popularity.

Related formats include 3GP (the 3GPP container) and MP4; 3G2 files are decoded by most general-purpose media players and editor tools with appropriate codecs and container support.