MXF to AU Converter
FileFlip converts MXF 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 MXF file to AU?#
- Drop your MXF 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 MXF to AU lose quality?#
It depends on what is inside the file. MXF 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 MXF files online?#
Yes, because nothing is uploaded. FileFlip converts MXF 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 MXF to AU actually does to the file#
Converting MXF 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: MXF → 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 MXF file?#
An MXF file wraps video, audio and extensive metadata for broadcast and post-production, a SMPTE container designed to move footage between cameras, editing systems and archives without losing timecode, captions or provenance along the way.
Use MXF for broadcast delivery, tapeless camera ingest or any post-production pipeline where downstream tools expect the metadata and operational pattern a plain container cannot carry.
Convert MXF to MP4 or MOV once a project leaves the broadcast or post-production chain, for review copies, web delivery, or anywhere the metadata MXF exists to carry is no longer needed.
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.
MXF to AU questions people ask#
What is an MXF file used for?
MXF is the file professional cameras, editing systems and broadcasters exchange footage in, because it carries timecode, captions and other production metadata that a consumer container like MP4 has no place to store. Sony XDCAM and Panasonic P2 cameras record directly to MXF, and it is the delivery format most TV stations and streaming platforms require.
Why won't my media player open an MXF file?
MXF is built for professional editing and broadcast tools, not general playback, and consumer media players often lack the demuxer for it. VLC opens most MXF files through its libavformat backend, but the codec wrapped inside the MXF still has to be one it supports, since MXF itself is just the container.
Why do two MXF files from different cameras behave differently?
MXF defines several operational patterns and can wrap many different video codecs, so a file's actual structure depends on which camera or system wrote it. Sony XDCAM and Panasonic P2 both produce standard-compliant MXF, but their early implementations diverged enough that files from one system did not always import cleanly into tools built around the other.
What creates an AU file?
AU files come from Unix and Sun workstation software, from Java's built-in sound APIs, and from older system sound effects, since AU was the default audio format on SunOS and NeXT machines. Websites in the 1990s also used it for embedded sound clips before WAV and MP3 became standard.