3GP is a multimedia container format defined by the Third Generation Partnership Project
for 3G UMTS multimedia services.
It is used on 3G mobile phones but can also be played on some 2G and 4G phones.
3G2 is a multimedia container format defined by the 3GPP2 for 3G CDMA2000 multimedia services.
It is very similar to the 3GP file format, but has some extensions and limitations in
comparison to 3GP.
Specifications 3GP is defined in the ETSI 3GPP technical
specification.
3GP is a required file format for video and associated speech/audio media types and timed
text in ETSI 3GPP technical specifications for IP Multimedia Subsystem, Multimedia Messaging
Service, Multimedia Broadcast/Multicast Service and Transparent end-to-end Packet-switched
Streaming Service.
3G2 is defined in the 3GPP2 technical specification.
Technical details
The 3GP and 3G2 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, which is also based on
MPEG-4 Part 12.
The 3GP and 3G2 file format were designed to decrease storage and bandwidth requirements
to accommodate mobile phones.
3GP and 3G2 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
Some cell phones use the .mp4 extension for 3GP video.
3GP The 3GP file format stores video streams as
MPEG-4 Part 2 or H.263 or MPEG-4 Part 10, and audio streams as AMR-NB, AMR-WB, AMR-WB+,
AAC-LC, HE-AAC v1 or Enhanced aacPlus.
3GPP allowed use of AMR and H.263 codecs in the ISO base media file format, because 3GPP
specified the usage of the Sample Entry and template fields in the ISO base media file
format as well as defining new boxes to which codecs refer.
These extensions were registered by the registration authority for code-points in ISO base media
file format.
For the storage of MPEG-4 media specific information in 3GP files, the 3GP specification refers
to MP4 and the AVC file format, which are also based on the ISO base media file format.
The MP4 and the AVC file format specifications described usage of MPEG-4 content in the ISO
base media file format.
A 3GP file is always big-endian, storing and transferring the most significant bytes first.
3G2 The 3G2 file format can store the same video
streams and most of the audio streams used in the 3GP file format.
In addition, 3G2 stores audio streams as EVRC, EVRC-B, EVRC-WB, 13K, 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 and AMR-WB+ audio streams.
For the storage of MPEG-4 media 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 file format
specification.
Device support Most 3G capable mobile phones support the
playback and recording of video in 3GP format.
Some newer/higher-end phones without 3G capabilities may also playback and record in this format.
Audio imported from CD onto a PlayStation 3 when it is set to encode to the MPEG-4 AAC
codec copies onto USB devices in the 3GP format.
The Nintendo DSi supports .3gp on an SD card.
Software support When transferred to a computer, 3GP movies
can be viewed on Windows, Mac OS X and Linux operating systems, with Windows Media Player,
MPlayer and VLC media player.
Programs such as Media Player Classic, K-Multimedia Player, Totem, RealPlayer, QuickTime, and
GOM Player can also be used.
3GP files can be encoded and decoded with open source software FFmpeg.
See also Comparison of container formats
References
External links 3GPP codecs specifications; 3G and beyond
/ GSM, 26 series 3GPP file format; 3GPP TS 26.244; Transparent
end-to-end packet switched streaming service - specification
3GPP2 specifications 3GPP2 File Formats for Multimedia Services;
3GPP2 C.S0050-B Version 1.0 - specification RFC 3839, MIME Type Registrations for 3rd
Generation Partnership Project Multimedia files
RFC 4393, MIME Type Registrations for 3GPP2 Multimedia Files
RFC 4281, The Codecs Parameter for "Bucket" Media Types
3GP FileExtension.org