The extension 3G2 identifies multimedia files, which are mostly generated by or intended for mobile phones. This standard was developed by the 3GPP2 organization for 3G-CDMA2000 phones. It is a modification of 3gp and has several extensions and limitations.
Like avi or Quicktime 3G2 is a container format. It is based on the MP4 container, but was adapted to the special conditions of mobile phones.
The video and audio data may be encoded in various compression methods. Subtitles are also supported.
The videos can also be protected with a DRM-like system. Then you need the respective, possibly paid license to view the content.
The support of the format by hardware players, be it phones or other devices, varies in severity. Most 3G-capable phones, but also some 2G and 4G phones support the format. How much depends on the capabilities of the hardware (storage space, display and camera resolution, etc.).
Many phones bring their own software for processing.
Many players support the 3G2 container, but whether the content can be displayed depends on the particular compression methods (codecs) used and their support by the player.
Most often resolving problems with opening 3G2 files is very simple. Just install an appropriate program that supports such files. All of the listed programs support 3G2 files, but may vary in offered function and purpose. Some programs may be capable only of viewing contents of 3G2 files or offer file conversion options, but may not be capable of editing such files.
It is possible that although a compatible program has been installed on user’s system, it is not used by the system to open it. This may happen because no default application was associated with this type of files. To associate 3G2 files with given application, select "Open with" from drop-down menu (accessed by right-clicking on the file). Then select from the list the program or application you want to be used to open this type of file. If the QuickTime Player applications is not on the list, select "Browse" option in order to manually locate the directory where QuickTime Player has been installed.
Sometimes problems with opening 3G2 files may not lie with the application itself, but can arise due to other causes, such as: