.3GP File Format – Brands and profiles

3GPP multimedia file

A 3GP file is an ISO base media file: the same boxes as MP4 (see its box structure), with the rules and extra boxes of 3GPP TS 26.244. What makes a file 3GP is the ftyp box and its brands. These pages follow TS 26.244 Release 19, read clause by clause, and the MP4 Registration Authority brand list.

ftyp in a 3GP file

OffsetSizeNameRule
84major brandThe file’s best use; should match the file extension. For a .3gp file, one of the profile brands below.
124minor versionFor a brand 3gLZ (L a letter, Z a digit) the file conforms to version Z.x.y of the specification, and the minor version is x × 256 + y.
164 × ncompatible brandsEvery profile the file conforms to. A file that also meets earlier releases should list 3gp4 to 3gp8 as well; without 3gp4 a Release 4 reader will not open it.

Readers should look through the compatible brands for one they know and not rely on the major brand. A typical file starts:

00 00 00 18 66 74 79 70 33 67 70 34 00 00 02 00   ....ftyp3gp4....
69 73 6F 6D 33 67 70 34                           isom3gp4

That is major brand 3gp4, minor version 0x200 (version 4.2.0 under the rule above), compatible with isom and 3gp4.

Release 9 profiles

BrandProfileConstraints
3gg9GeneralFewest restrictions; may hold alternative tracks. A superset of the other profiles, for files that fit none of them.
3gp9BasicSelf-contained (no external media); at most one video (or scene description), one audio and one text track; one sample entry per video and audio track; no references between tracks.
3gs9Streaming serverHint tracks for every media track, following 3GPP streaming; SDP for the session and media; streaming-server extensions (track selection) should be used.
3gr9Progressive downloadmoov directly after ftyp; media tracks interleaved with a depth of one second or less.
3ge9Extended presentationContains an extended presentation (TS 26.244 clause 11).
3gt9Media stream recordingRecorded streams in RTP (or, protected, SRTP) reception hint tracks or media tracks, with RTCP or SRTCP hint tracks, key message tracks and SDP.
3gf9File-delivery serverUses file delivery hint tracks and the file delivery extensions of ISO/IEC 14496-12, for sending over FLUTE.
3gh9Adaptive streamingmoov after ftyp (and any pdin), with no samples in it (stts, stsc, stco entry counts 0) and an mvex; then moof and mdat pairs, each moof with at least one track fragment, using default-base-is-moof addressing.
3gm9Media segmentLabels segments of this release; the segment rules are in TS 26.247.

All 3GPP and 3GPP2 brands

BrandMeaning
3gp4Release 4
3gp5Release 5
3gp6Release 6 basic profile
3gg6Release 6 general profile
3gr6Release 6 progressive-download profile
3gs6Release 6 streaming-server profile
3ge6Release 6 extended-presentation profile
3gp7Release 7
3ge7Release 7 extended-presentation profile
3gp8Release 8
3gt8Release 8 media stream recording profile
3gp9Release 9 basic profile
3gg9Release 9 general profile
3gr9Release 9 progressive-download profile
3gs9Release 9 streaming-server profile
3ge9Release 9 extended-presentation profile
3gt9Release 9 media stream recording profile
3gf9Release 9 file-delivery server profile
3gh9Release 9 adaptive streaming profile
3gm9Release 9 media segment profile
3gmAMedia segment in the 3GP-DASH media segment format
3gtvTV over 3GPP services
3gvr3GPP VR presentation
3vra3GPP VR advanced video media profile
3vrb3GPP VR basic video media profile
3vrm3GPP VR main video media profile
3g2a3GPP2 file (.3g2), defined by 3GPP2 C.S0050

The Release 9 profile brands are the ones TS 26.244 Release 9 and later define; later releases keep these codes. 3GPP2’s .3g2 files follow 3GPP2’s own specification, which is not covered here beyond its brand and its sample entries.

styp

A segment starts with a segment type box, styp, laid out like ftyp. Its brands should include those of the ftyp before the moov, and may add others such as 3gm9. A styp that is not first in its file may be ignored, and may be dropped when segments are joined.