M2TS to AU Converter
FileFlip converts M2TS to AU entirely inside your browser, using FFmpeg compiled to WebAssembly. The file is never uploaded to a server: it is read off your disk, converted on your own machine, and saved back by the browser. That means no file-size limit, no queue and no account.
How do I convert an M2TS file to AU?#
- Drop your M2TS file onto the converter at the top of this page, or click it to pick one from your computer. You can add as many as you like.
- Leave the target set to AU and the conversion starts on its own. FileFlip downloads 30.8 MB of WebAssembly the first time and nothing after that, then runs FFmpeg on your own machine.
- Save the AU file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting M2TS to AU lose quality?#
It depends on what is inside the file. M2TS is a container rather than a codec, so whether the AU conversion copies the streams across untouched or re-encodes them is decided by the codecs that particular file happens to use.
Is it safe to convert M2TS files online?#
Yes, because nothing is uploaded. FileFlip converts M2TS files inside the browser tab you already have open, using WebAssembly builds of the same engines a desktop converter would install. Your file is read from your own disk into the page's memory, and no request carrying it is ever made.
You do not have to take that on trust. Open your browser's network panel, run a conversion, and you will see the engine come down and your file go nowhere. There is no upload, no server-side copy, no retention window, and no account tied to what you converted.
How FileFlip works lists every engine, its version and its download size, and shows how to check for yourself that nothing leaves your machine.
What M2TS to AU actually does to the file#
Converting M2TS to AU runs on FFmpeg, downloads 30.8 MB of WebAssembly the first time and nothing after that, re-encodes or copies through depending on the codecs in the file, and drops encoded streams and video tracks.
| Engine | FFmpeg |
|---|---|
| Conversion path | One step: M2TS → AU |
| Downloaded to your browser | 30.8 MB, once, then cached by your browser |
| Quality | Decided by the codecs inside the file |
| You get back | One file |
| Where it runs | In a background worker, so the page stays responsive |
What survives the conversion
| What is in the file | This conversion | Why |
|---|---|---|
| Encoded streams | Dropped | The target format has nowhere to put it. |
| Video tracks | Dropped | The target format has nowhere to put it. |
What is an M2TS file?#
An M2TS file holds a BDAV MPEG-2 transport stream, the timestamped variant of MPEG-TS that Blu-ray Disc authoring software writes into a disc's BDMV/STREAM folder.
Keep footage as M2TS while it's still part of a Blu-ray authoring or playback pipeline that expects that exact stream structure.
Convert M2TS to MP4 or MKV once the goal is normal playback or editing outside of Blu-ray software, since both drop the disc-specific overhead while keeping the same video and audio.
What is an AU file?#
An AU file holds audio in Sun Microsystems' Unix workstation format, a plain header followed by raw sample data that was the standard system-alert and early web audio format before WAV and MP3 took over.
AU still shows up as the format Java's javax.sound and some Unix system tools default to for short sound effects, where its simplicity is the point.
Convert AU to WAV or MP3 when the audio needs to play in modern media players, browsers, or editing software that no longer ship AU support by default.
M2TS to AU questions people ask#
What produces an M2TS file?
M2TS files come from Blu-ray Disc authoring software, from ripping or ejecting a Blu-ray's BDMV/STREAM folder, and from professional camcorders that record straight to the Blu-ray-compatible format. Any tool built around the Blu-ray Disc Association's BDAV structure writes this extension.
Why won't my M2TS file play?
Most general media players struggle with M2TS because it expects the surrounding disc structure or a codec the player doesn't have, particularly for VC-1 or high-bitrate H.264 video. VLC decodes M2TS directly without needing the rest of the disc, so it's the most reliable first thing to try.
What's the difference between M2TS and MTS?
They're the same BDAV MPEG-2 transport stream underneath. M2TS is the extension Blu-ray Disc authoring software and players use for the STREAM folder on a disc, while MTS is the extension the AVCHD camcorder standard assigns to the identical stream structure when it's recorded onto a memory card instead of a disc.
What should I convert an M2TS file to?
Convert M2TS to MP4 for general playback and sharing, or to MKV if the goal is to keep every audio track and subtitle stream a Blu-ray rip contains. Either drops the disc-specific packet overhead without touching the underlying video quality.