Editing 3GP and 3G2 (section)

===3GP===
The 3GP file format stores video streams as [[MPEG-4 Part 2]], [[H.263]], or [[H.264|MPEG-4 Part 10 (AVC/H.264)]], and audio streams as [[Adaptive Multi-Rate|AMR-NB]], [[AMR-WB]], [[AMR-WB+]], [[Advanced Audio Coding|AAC-LC]], [[HE-AAC]] v1 or Enhanced aacPlus (HE-AAC v2). 3GPP allowed use of AMR and H.263 codecs in the ISO base media file format (MPEG-4 Part 12), 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 ("MP4 Family" files).<ref name="mpeg4part12-3gp">{{cite web
  | title = ISO/IEC 14496-12:2008, Information technology -- Coding of audio-visual objects -- Part 12: ISO base media file format
  | publisher = [[International Organization for Standardization]]
  | year = 2008
  | url = http://standards.iso.org/ittf/PubliclyAvailableStandards/c051533_ISO_IEC_14496-12_2008.zip
  | format = PDF
  | page = 95
  | access-date = 2009-05-30 
 }} 
</ref><ref name="mp4ra">{{cite web
 |title       = Registered types – Codecs
 |publisher   = Registration authority for code-points in "MP4 Family" files – mp4ra.org
 |year        = 2008
 |url         = http://www.mp4ra.org/codecs.html
 |access-date  = 2009-05-31
 |archive-url  = https://web.archive.org/web/20090419074514/http://www.mp4ra.org/codecs.html
 |archive-date = 2009-04-19
 |url-status     = dead
}}</ref> 

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.<ref name="3gp-spec-mpeg4part12" />

A 3GP file is always [[Endianness|big-endian]], storing and transferring the most significant bytes first. {{Citation needed|date=September 2017}}