3GPP to M2TS Converter

3GPP to M2TS Converter

A .3gpp file is a mobile-phone clip in the 3GPP container — the same format as .3gp, just spelled out. A .m2ts file is a BDAV-framed MPEG transport stream: the packet layout Blu-ray and AVCHD use, and the spelling most non-linear editors expect when they import camcorder footage onto a computer.

That word "BDAV" is the whole point of this page. .m2ts is not simply .ts with a longer name — the packets are physically laid out differently, and this converter writes the BDAV form. Everything below explains what that means for your file, what audio codec you should pick, and where this conversion is genuinely the right call.

What BDAV Framing Actually Does to the Bytes

A plain transport stream is a run of 188-byte packets, each starting with the sync byte 0x47. BDAV wraps every one of those packets in a 4-byte arrival-timestamp header, producing 192-byte units where the sync byte now sits at offset 4. That header is what Blu-ray players and AVCHD tools use to pace playback.

We encoded one 3GPP clip twice with identical settings, changing only the output extension:

The .m2ts is 2.56% larger from the same encode, which is the 4-byte-in-192 overhead almost exactly. The practical consequence is the one people get wrong: renaming a .ts or .mts file to .m2ts does not add the framing. You get a mislabelled plain stream, and any tool that validates BDAV structure will see through it. Convert to the spelling you need rather than renaming into it.

How to Convert 3GPP to M2TS

1. Upload Your 3GPP File: Drag the .3gpp clip onto the page or click "+ Add Files". Batch uploads convert with a single set of settings.
2. Leave Video Codec on H.264: The dropdown also offers H.265, MPEG-2, MPEG-1, MPEG-4, Xvid and DivX, but H.264 is the codec BDAV-based formats are built around and the only one AVCHD tools reliably accept. There is no reason to change it for this target.
3. Consider Switching Audio Codec to AC3: The page defaults to AAC. AAC is a perfectly good codec and a general-purpose transport stream carries it happily — but it is not one of the audio formats AVCHD and Blu-ray define. If the .m2ts is bound for an AVCHD-aware editor or authoring tool, choose AC3 instead. AAC, EAC3, MP2 and MP3 are also listed.
4. Set Resolution or Trim, Then Convert: Video resolution opens on Keep original, which is what you want for phone footage; Trim opens on "Unchanged" and takes a Time Range. Click Convert to download the .m2ts. Files are uploaded over an encrypted connection, processed on our servers, and deleted automatically after a few hours — no sign-up, no watermark.

3GPP Source vs M2TS Output

Frequently Asked Questions

Is the .m2ts this tool produces a valid AVCHD file?

The stream is right, the audio default is not, and a single file is not a disc. The BDAV framing and the H.264 video are exactly what AVCHD expects. The default AAC soundtrack is not — AVCHD defines Dolby AC-3 and uncompressed linear PCM as its audio formats. Switch Audio Codec to AC3 before converting if AVCHD compatibility matters. Beyond that, a genuine AVCHD disc also needs the surrounding BDMV folder structure with its index and playlist files, which no single-file conversion can produce; an authoring tool builds that around the stream you supply.

Why does the M2TS come out larger than a .ts of the same clip?

Because BDAV adds four bytes to every packet. A plain transport stream stores 188-byte packets; BDAV prefixes each one with a 4-byte arrival timestamp, so the same payload occupies 192 bytes instead of 188. That is roughly 2.1% of pure overhead, and in our measurement the finished .m2ts came out 2.56% larger than the identical encode written as .ts once program tables and padding were counted. The picture and sound are unchanged; you are paying for the timing headers.

Can I rename a .ts or .mts file to .m2ts instead of converting?

No, and this is the single most common mistake with these extensions. .ts and .mts files contain plain 188-byte packets with the sync byte at the start of each one; a real .m2ts has 192-byte BDAV units with a timestamp header in front. Renaming changes the label without touching a single byte of framing. Some permissive players will not care, but the tools that specifically want .m2ts — authoring software, Blu-ray-aware editors — check the structure and will reject a renamed file.

Should I use .mts or .m2ts for my editor?

Try .mts first if the footage is meant to look like camcorder media, and .m2ts if it is meant to look like something already imported to a computer or read from a disc. That is the convention the formats grew up with: camcorders write .mts onto their own storage and the same clips appear as .m2ts once transferred. If your editor is specific about it, convert directly to the one it wants — 3GPP to MTS writes the plain framing and this page writes BDAV.

Will converting my phone clip to M2TS make it look like camcorder footage?

Only in file structure. A .3gpp recording was captured at QCIF or CIF resolution with a low bitrate, and no container change adds detail that was never there. Setting a 1080p resolution preset produces a 1080p file that still looks like upscaled phone video, only several times larger. Leave Video resolution on "Keep original" and let the editor position the small clip on its HD timeline — as an insert, a picture-in-picture, or with the frame scaled at playback time where the scaling is at least reversible.

What audio codec should I pick, and why is AAC the default?

AAC is the default because it is the sensible general-purpose choice for a transport stream and the codec most players decode. It is the wrong choice if the destination is an AVCHD or Blu-ray workflow, where AC-3 and linear PCM are the defined formats — pick AC3 there. One caution about the list: DTS (DCA) appears among the options, but our pipeline treats the DTS encoder as experimental and substitutes AC-3 before the job runs, so choosing it gets you an AC-3 track under a different name. Select AC3 directly if that is what you want.

My source audio is 8 kHz AMR — does that matter here?

It limits what any output codec can carry. AMR-NB samples at a fixed 8 kHz and keeps roughly the telephone band from 200 Hz to 3.4 kHz; everything outside that was discarded by the handset when it recorded. Re-encoding into AAC or AC-3 preserves what survived and cannot reconstruct the rest. Worth knowing if you plan to drop the clip onto a timeline with 48 kHz camcorder audio: the phone track will sound obviously narrower, and that difference is baked into the source rather than introduced by the conversion.

Is .3gpp different from .3gp?

No. They are two spellings of the same 3GPP container, built on the ISO base media file format and defined in 3GPP TS 26.244. A file with either extension has the same internal structure, and renaming between them changes nothing. This page reads .3gpp uploads; 3GP to M2TS is the identical conversion for the shorter spelling.

What plays a .m2ts file after conversion?

VLC handles .m2ts on Windows, macOS and Linux without extra components, and professional editors — Premiere Pro, DaVinci Resolve, Vegas — import them as a matter of course since that is the format camcorder footage arrives in. Consumer players and browsers generally will not: the format is a professional and disc-oriented one rather than a sharing one. If you want a file that opens anywhere, convert to 3GPP to MP4 instead, which carries the same H.264 video without the BDAV packaging.

How are my files handled during conversion?

The .3gpp you upload is transferred over an encrypted connection, converted on our servers, and deleted automatically a few hours later along with the .m2ts we produced. Nothing is shared or made public and no account is required. In our testing a 402 KB 10-second 3GPP clip produced a 590 KB .m2ts at the default H.264 and AAC settings, so files from this route are small and the round trip is quick.