3GP Video
Convert 3GP files to MP4, WebM, or GIF directly in your browser — no upload, no server. FileDex uses FFmpeg WASM to transcode legacy mobile video locally, keeping your recordings private.
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أسئلة شائعة
How do I play 3GP files on my computer?
Install VLC Media Player, which includes built-in decoders for all 3GP codecs (H.263, AMR-NB, AMR-WB). Alternatively, convert the 3GP to MP4 using FileDex in your browser for universal playback without installing any software.
Can I convert 3GP to MP4 without losing quality?
If the 3GP contains H.264 video and AAC audio, yes — FileDex can remux (container swap) to MP4 with zero quality loss. If it uses H.263 or AMR codecs, transcoding is required, but CRF 23 in H.264 produces visually identical results at the typically low resolutions of 3GP recordings.
Why are 3GP files so small compared to MP4?
3GP files were designed for 3G mobile networks with limited bandwidth. They use low resolutions (176x144 to 320x240), low frame rates (12-15fps), and aggressive compression settings. The small size comes from reduced quality, not from superior compression technology.
What happened to the 3GP format?
3GP was the standard mobile video format from 2001 to roughly 2010. The iPhone (2007) and Android standardized on MP4 with H.264/AAC for video recording, making 3GP obsolete. Modern phones no longer record in 3GP, but billions of legacy 3GP files still exist from the feature phone era.
ما يميز .3GP
Mobile video in the early 2000s demanded a container format that could play on devices with 2 MHz processors, 32 KB of RAM, and no floating-point unit. 3GP answered that demand. Defined by the 3rd Generation Partnership Project (3GPP) as part of the Release 5 specification in 2002, 3GP is a simplified profile of the ISO Base Media File Format (ISOBMFF) — the same foundation underlying MP4. The critical difference: 3GP mandates support for H.263 and AMR-NB codecs at a maximum 176x144 resolution as the baseline profile, ensuring any 3GPP-compliant phone from 2003 onward can play the file regardless of manufacturer.
اكتشف التفاصيل التقنية
Container structure
3GP uses the same atom/box hierarchy as MP4. A valid 3GP file contains ftyp, moov, and mdat boxes. The ftyp box declares the brand as 3gp4, 3gp5, or 3gp6 depending on the specification version, which signals to the player which codecs to expect.
| 3GP version | Year | Max video codec | Max audio codec |
|---|---|---|---|
| 3GPP Release 5 | 2002 | H.263 Profile 0 Level 10 | AMR-NB 12.2 kbps |
| 3GPP Release 6 | 2004 | H.264 Baseline Level 1 | AMR-WB 23.85 kbps |
| 3GPP2 (3G2) | 2003 | MPEG-4 Part 2 Simple | EVRC 9.6 kbps |
3GPP2 (.3g2) is the CDMA variant used by carriers like Verizon and Sprint. It supports EVRC audio instead of AMR and uses different file type brands. The two formats are structurally identical but target different network standards.
Codec profiles and bitrate constraints
The baseline H.263 Profile 0 Level 10 codec operates at 64 kbps maximum video bitrate with QCIF resolution (176x144). At this quality level, a 30-second video clip occupies roughly 240 KB. AMR-NB (Adaptive Multi-Rate Narrowband) audio compresses speech to 4.75-12.2 kbps using a codebook-excited linear prediction model optimized for voice, not music.
Release 6 added H.264 Baseline Profile support, dramatically improving quality. A 320x240 H.264 video at 384 kbps with AMR-WB audio looks reasonable on a 2-inch screen. The codec upgrade mattered because carriers began offering video messaging (MMS) with file size limits of 300 KB to 1 MB, and H.264 delivered roughly 3x the visual quality per bit compared to H.263.
MMS and carrier integration
Multimedia Messaging Service was 3GP's primary distribution channel. Carriers imposed strict file constraints:
- File size: 100 KB to 600 KB depending on carrier
- Duration: 15-30 seconds maximum
- Resolution: 176x144 (QCIF) or 320x240 (QVGA)
- Bitrate: 64-384 kbps combined
These limits shaped the format's identity. 3GP was never designed for feature films or high-quality video. It existed to move short clips across 2G and 3G cellular networks where bandwidth was measured in kilobits.
Why 3GP still exists
Billions of 3GP files sit in phone backups, carrier archives, and forensic evidence stores. Feature phones running Symbian, BREW, and Java ME recorded natively to 3GP. Many of these recordings are irreplaceable — early smartphone footage of events, personal memories from 2003-2012, and MMS messages stored on carrier servers.
FileDex converts 3GP to MP4 in the browser by re-muxing H.264 streams directly (no re-encode needed) or transcoding H.263 content to H.264. AMR audio requires transcoding to AAC since no modern browser supports AMR playback natively.
Limitations and alternatives
3GP offers no subtitle support, no chapter markers, and no HDR metadata. Its maximum practical resolution tops out at 720x480 in later profiles. For any modern mobile video workflow, MP4 with H.264 or H.265 is the correct choice. Android and iOS both record to MP4 natively. 3GP's role today is purely archival — a format you convert from, never to.
حوّل .3GP إلى...
المرجع التقني
- نوع MIME
video/3gpp- Magic Bytes
00 00 00 xx 66 74 79 70 33 67 70ftyp box with 3gp brand.- المطوّر
- 3rd Generation Partnership Project
- سنة التقديم
- 2001
- معيار مفتوح
- نعم
ftyp box with 3gp brand.
البنية الثنائية
3GP files use the ISO Base Media File Format (ISOBMFF), the same box-based structure as MP4 and MOV. The file begins with an ftyp box at offset 0, declaring the major brand '3gp4', '3gp5', or '3gp6' with compatible brands. The moov box contains the movie-level metadata: mvhd (movie header with timescale, duration), followed by one or more trak boxes. Each trak has a tkhd (track header), mdia (media container with mdhd, hdlr, and minf), and stbl (sample table). The stbl box is the index: stsd describes the codec (s263 for H.263, mp4v for MPEG-4 Visual, avc1 for H.264, samr for AMR-NB, sawb for AMR-WB), stts maps sample-to-time, stsc maps sample-to-chunk, stsz holds sample sizes, and stco/co64 holds chunk offsets into the mdat box. The mdat box contains the raw compressed media data. In files recorded by mobile devices, the moov box is often placed after mdat, requiring a full file read before playback can begin.
| Offset | Length | Field | Example | Description |
|---|---|---|---|---|
0x00 | 4 bytes | Box size | 00 00 00 14 | Size of the ftyp box in bytes (big-endian uint32). Typically 20 bytes for 3GP. |
0x04 | 4 bytes | Box type | 66 74 79 70 | ASCII 'ftyp' — file type identification box, always first in ISOBMFF. |
0x08 | 4 bytes | Major brand | 33 67 70 35 | ASCII '3gp5' (3GPP Release 5). Other values: '3gp4' (Release 4), '3gp6' (Release 6). |
0x0C | 4 bytes | Minor version | 00 00 01 00 | Version of the brand specification (big-endian uint32). |
0x10 | variable | Compatible brands | 33 67 70 35 69 73 6F 6D | List of compatible brands. Common: 3gp5, isom, mp41. Determines which decoders can handle the file. |
variable | variable | moov box | 6D 6F 6F 76 | Movie metadata container. Holds track definitions, codec descriptions (stsd), and sample index tables (stbl). |
variable | variable | mdat box | 6D 64 61 74 | Media data box containing compressed H.263/H.264 video frames and AMR/AAC audio samples. |
نقاط الضعف
- Malformed moov/stbl boxes — crafted box sizes can trigger integer overflows in parsers (ISOBMFF-wide vulnerability class)
- AMR decoder exploits — malformed AMR frames have caused buffer overflows in older Android media frameworks (e.g., Stagefright)
- Oversized mdat reference — stco entries pointing beyond file boundary cause read past end of file
الحماية: FileDex decodes 3GP entirely in the browser sandbox using FFmpeg WASM. No server-side processing, no file upload. The WASM memory sandbox prevents any buffer overflow from reaching the host system.