M4V to M2TS Converter

M4V to M2TS Converter

M4V is Apple's video flavour of the MPEG-4 container — structurally an MP4, usually holding H.264 video and an AAC soundtrack. M2TS is something quite different: the BDAV transport stream that Blu-ray discs, AVCHD camcorder recordings and disc-authoring software use, where the same H.264 video is chopped into fixed-size transport packets instead of sitting in an ISO-style container. This page rebuilds your M4V into that structure. It also tells you the two settings you almost certainly need to change to end up with something an AVCHD authoring tool or a standalone Blu-ray player will actually accept.

M2TS Format at a Glance

What This Converter Writes — and What You Have to Set Yourself

The framing is handled for you: the .m2ts written here is genuinely BDAV-packetised, not a plain transport stream under a fancier extension. We checked the bytes rather than trusting the muxer's documentation — the same encode written as .ts comes out in flat 188-byte packets, while the .m2ts comes out in 192-byte packets with the four-byte arrival-timestamp header ahead of each sync byte. That is the structure Blu-ray and AVCHD parsers look for.

What is not handled for you is spec compliance of the streams inside. Three of the starting selections are chosen for general-purpose conversion, not for disc authoring:

The Video Codec dropdown also offers H.265, MPEG-1, MPEG-4, DivX and Xvid. Those mux into a transport stream perfectly well, and are fine if your target is a media player or a software pipeline, but none of them is a Blu-ray or AVCHD video format — a standalone player will reject the result.

How to Convert M4V to M2TS

1. Upload Your M4V File: Drag your .m4v onto the page or click "Add Files". .mp4 sources are accepted too, and several clips can be queued and converted in one batch. FairPlay-protected iTunes purchases cannot be converted.
2. Set the Video and Audio Codec: Video Codec starts on H.264, which is what you want. Change Audio Codec from its starting AAC to AC3 if the file is destined for a disc or a standalone player; AAC is fine if you are only feeding a software player or media server.
3. Set Resolution and Rate Control: Video resolution starts on Keep original and does not downscale on its own, so choose 1080p or 720p from Preset Resolutions for AVCHD targets — the list is by height, with width following your source's aspect ratio. Under File Compression, Constraint Quality or Variable Bitrate let you cap the peak bitrate; Trim exports a single time range.
4. Convert and Download: Click Convert and save the .m2ts. Your file is uploaded over an encrypted connection, encoded on our servers and deleted automatically a few hours later. No sign-up, no watermark.

Turning the .m2ts Into a Playable Disc

A single .m2ts is a stream, not a disc. A Blu-ray or AVCHD volume needs the whole BDMV/ directory around it: the STREAM/ folder holding your .m2ts, PLAYLIST/ holding the .mpls playlists, CLIPINF/ holding the .clpi clip-information files, and the index objects that tell a player what to do when the disc is inserted. Those are generated by authoring software, not by a converter — multiAVCHD, tsMuxeR, ImgBurn with an AVCHD template, or the disc tools built into editing suites such as Vegas and EDIUS. Drop the converted stream into the authoring app's input list and it assembles the folder structure, which you then burn to DVD-R for AVCHD or BD-R for Blu-ray. If you only ever wanted a file that plays on phones, browsers and TVs without any of this, M4V to MP4 is the target you actually want. Coming the other way, M2TS to M4V unwraps a stream back into an Apple-friendly container.

Frequently Asked Questions

My M4V is already H.264 — why does it need re-encoding at all?

Because the container, the packet framing and the audio all change. An M4V wraps H.264 in an ISO base-media container with AAC audio and a single index at the front or back of the file. M2TS chops the same kind of video into 192-byte BDAV packets with per-packet arrival timestamps, and disc players expect AC-3 or LPCM audio rather than AAC. The video is re-encoded rather than copied through, so treat the original M4V as your master and this output as the disc-bound derivative.

What is the difference between .m2ts and .mts?

Naming convention only. .MTS is the 8.3-style filename AVCHD camcorders write directly onto SD cards, and .m2ts is the long-filename form used inside BDMV/STREAM/ on a finished disc. The bytes are the same BDAV transport stream in both cases. If your workflow specifically expects the camcorder-style extension, use M4V to MTS instead.

Why should I change the Audio Codec, and to what?

Because the dropdown starts on AAC, and AAC is not part of the AVCHD specification. AVCHD allows Dolby Digital (AC-3), at bitrates from 64 kbit/s up to 640 kbit/s, or uncompressed linear PCM. A software player will happily play AAC inside an .m2ts, but authoring tools and standalone Blu-ray players may refuse the stream or play it silently. Switch Audio Codec to AC3 whenever the file is headed for a disc. AC3, EAC3, DTS (DCA), MP2 and MP3 are the alternatives offered here.

Will a 4K M4V be downscaled automatically for AVCHD?

No, and this catches people out. Video resolution starts on Keep original, so a 4K source stays 4K and produces a stream no AVCHD device will touch — the specification tops out at 1920×1080. Set Preset Resolutions to 1080p (or 720p) yourself before converting. The presets are heights and the width follows your source's aspect ratio.

What bitrate should I target?

Stay under 24 Mbit/s peak for standard AVCHD 1.0 playback, which covers most standalone players and camcorder-era hardware; DVD-based AVCHD is tighter still at 18 Mbit/s. An AVCHD 2.0 authoring chain and a player that supports it will accept up to 28 Mbit/s. Use Constraint Quality or Variable Bitrate under File Compression and set the max-bitrate field — the default Quality Preset mode targets visual quality, not a bitrate ceiling, so it cannot guarantee compliance on complex footage.

Can I convert an M4V I bought or rented from the iTunes Store?

No. Purchases and rentals can carry Apple's FairPlay protection, which encrypts the video so it decodes only on a device authorised with the buying Apple ID. No web converter can read that stream. A quick test: an M4V that plays on your Apple devices but refuses to open in VLC is almost certainly FairPlay-locked. DRM-free M4V files — your own exports, camera footage, screen recordings — convert normally.

My source is 1080i camcorder footage. Will the conversion deinterlace it?

No. There is no deinterlacing anywhere in this pipeline, so interlaced fields pass through exactly as recorded and any combing stays in the output. For AVCHD that is often what you want, since the specification is built around interlaced 1080i and the player or television handles it. If you need a clean progressive file for editing or web use, deinterlace in a desktop editor first.

How are my files handled, and is there a size limit?

Files are uploaded over an encrypted connection, encoded on our servers, and deleted automatically a few hours later — no sign-up, no watermark, never shared or made public. There is no fixed cap on clip length or batch size; the real constraint on a multi-gigabyte HD source is upload time and connection stability, so if you only need one scene on the disc, use the Trim control to export just that range rather than converting the whole file.