3G2 Video Format

What is 3G2 video format? 3G2 video format (3GPP2 video format) is a multimedia container format defined by the 3GPP2 for 3G CDMA2000 multimedia services. It is very similar to 3GP video format, but has some extensions and limitations in comparison to 3GP. 3G2 is defined in 3GPP2 technical specification.

The 3G2 video format can store the same video streams and most of audio streams used in the 3GP video format. In addition, 3G2 stores audio streams as EVRC, EVRC-B, EVRC-WB, 13K (QCELP), SMV or VMR-WB, which was specified by 3GPP2 for use in ISO base media file format. The 3G2 specification also defined some enhancements to 3GPP Timed Text. 3G2 file format does not store Enhanced aacPlus (HE-AAC v2) and AMR-WB+ audio streams. For the storage of MPEG-4 media (MPEG-4 Part 2, MPEG-4 Part 3 - AAC, MPEG-4 Part 10 - H.264/AVC) in 3G2 files, the 3G2 specification refers to the MP4 file format and the AVC file format specification, which described usage of this content in the ISO base media file format. For the storage of H.263 and AMR content 3G2 specification refers to the 3GP video format specification. Some cell phones use the .mp4 extension for 3GP video.

3GP and 3G2 video file formats are both structurally based on the ISO base media file format defined in ISO/IEC 14496-12 - MPEG-4 Part 12, but older versions of the 3GP file format did not use some of its features. 3GP and 3G2 are container formats similar to MPEG-4 Part 14 (MP4), which is also based on MPEG-4 Part 12. 3GP and 3G2 video format were designed to decrease storage and bandwidth requirements in order to accommodate mobile phones.

3GP and 3G2 video file formats are similar standards, but with some differences:
?3GPP file format was designed for GSM-based Phones and may have the filename extension .3gp
?3GPP2 file format was designed for CDMA-based Phones and may have the filename extension .3g2