M4V to AU Converter

Extract M4V audio as Sun/NeXT AU sound files

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Unix Standard

AU is native to Sun/Unix systems. Extract M4V audio for server-side processing, Unix tools, and cross-platform workflows.

Online Processing

No Unix command-line tools needed — convert M4V to AU entirely through our browser-based cloud converter.

Privacy First

Uploaded M4V files are erased immediately. AU output is deleted within 24 hours from our servers.

How to convert M4V to AU

1

Select files from Computer, Google Drive, Dropbox, URL or by dragging it on the page.

2

Choose au or any other format you need as a result (more than 200 formats supported)

3

Let the file convert and you can download your au file right afterwards

About formats

M4V is a video container format developed by Apple Inc. and introduced alongside the iTunes Video Store in October 2005. Technically, M4V is nearly identical to the standard MP4 format (MPEG-4 Part 14), with the primary distinction being optional FairPlay DRM protection applied to purchased content from the iTunes Store. Unprotected M4V files are fully compatible with any player that handles MP4, as the underlying container structure and codec support are the same. The format typically contains H.264 video and AAC audio, supporting resolutions up to 4K and features like chapter markers, subtitle tracks, and metadata tags for title, artwork, and ratings. Apple chose the M4V extension to distinguish iTunes content from generic MP4 files, primarily so that DRM-protected purchases would be recognized by the Apple ecosystem of devices and software. M4V files play natively on macOS, iOS, iPadOS, and Apple TV, and unprotected versions work seamlessly in most major media players across all platforms. The format gained significant traction as the iTunes Store became a dominant platform for purchasing and renting digital movies and TV shows. Compatibility with the broader MP4 ecosystem means that video and audio streams within DRM-free M4V files can be processed by virtually any modern editing or transcoding tool without conversion.
Developer: Apple Inc.
Initial release: October 2005
AU is an audio file format introduced by Sun Microsystems for its Unix workstations and the NeXT platform. It features a minimal 24-byte header specifying data offset, size, encoding type, sample rate, and channel count, followed by the audio payload. AU supports numerous encodings, including uncompressed linear PCM at various bit depths, mu-law and A-law companding (logarithmic compression used in telephone systems), and several ADPCM variants. This versatility made AU a workhorse across early Unix environments, web audio (Java applets defaulted to AU), and telephony applications. One advantage is simplicity: the compact header and straightforward structure make it trivial to parse, generate, and stream programmatically. The built-in mu-law option provides another benefit, delivering reasonable voice quality at just 8 KB per second — half the rate of 16-bit uncompressed audio — invaluable when storage and bandwidth were scarce. Although modern formats have largely supplanted AU in consumer applications, it retains a foothold in scientific computing and audio processing pipelines where minimal overhead and reliable cross-platform behavior are valued.
Developer: Sun Microsystems
Initial release: 1992

Frequently Asked Questions

Why convert M4V to AU?

AU is the standard audio format on Sun/Unix systems. Converting M4V audio to AU provides compatibility with Unix-based audio tools.

What opens AU files?

Audacity, VLC, SoX, and most Unix audio utilities handle AU natively. It is a simple, well-documented format across platforms.

Is AU a modern format?

AU dates back to Sun Microsystems but remains practical for Unix scripting, web audio (Java), and cross-platform audio exchange.

Does AU support high quality?

AU supports various encodings including 16-bit and 32-bit PCM at any sample rate. Quality depends on the encoding you select.

Can I batch convert?

Upload multiple M4V files and extract AU audio from each simultaneously. All files process in a single session.