Differences between mp4 & 3gpp file format

Differences in MP4 & 3GPP (Audio) file formats:
# 3GP is a simplified version of the MPEG-4 Part 14 (MP4) container format, designed to decrease storage and bandwidth requirements in order to accommodate mobile phones.
# 3GPP stores video streams as MPEG-4 Part 2 or H.263 or MPEG-4 Part 10 (AVC/H.264), and audio streams as AMR-NB or AMR-WB or AAC-LC.ISO/IEC 26234-7XX documents and ISO/IEC 14496-12,14 standard. http://www.iso.org]
# .3gp, .3g2 used by mobile phones can also include content not defined for .mp4 i.e. H.263, AMR.3GPP TS 26.244 V7.1.0 (2007-03) document : http://www.3gpp.org]
# In 3GPP, Compact sample sizes ('stz2') shall not be used for tracks containing H.263, MPEG-4 video, AMR, AMR-WB, AAC or Timed text.
# All index numbers used in the 3GPP file format start with the value one rather than zero.
# BIFS scene description tracks or OD Object descriptors are optional in 3GPP. This systems tracks are needed for interactivity and more complex presentation in MP4 files.
# In 3GPP, the inclusion of MPEG-4 media does not imply the usage of MPEG-4 systems architecture.
# The major, minor brands supported in both file formats might differ in preference & precedence over each other. [ [http://www.ftyps.com Complete List of all known MP4/QT 'ftyp' designations ] ]
# All 3GP files of Release 5 or later shall contain compatible brand ‘isom’ indicating that they conform to the ISO base media file format.

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