RM to AU Converter

Extract Sun AU audio from RealMedia recordings

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Audio Rescue

Save audio from obsolete RM format. AU keeps your RealMedia content usable for Unix and Java applications.

Cloud Processing

AU extraction from RM runs on our servers — no legacy software needed on your system.

Secure Pipeline

RM uploads are deleted after extraction. AU output is purged from servers within 24 hours.

How to convert RM 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

RM (RealMedia) is a proprietary multimedia container format developed by RealNetworks beginning in 1997. The format was designed specifically for streaming media delivery over the internet, packaging RealVideo and RealAudio codecs into a container optimized for low-bandwidth playback. RM became one of the dominant streaming formats in the late 1990s and early 2000s, when RealPlayer was among the most widely installed media applications and RealNetworks pioneered the concept of buffered streaming video before broadband became widespread. The format uses constant bit rate encoding and a proprietary container structure that supports forward error correction, allowing reasonably smooth playback even over unreliable dial-up connections. RM files can contain multiple streams at different bit rates, enabling SureStream technology that adapts playback quality to available bandwidth) in real time. The container supports metadata for title, author, and copyright information, and RealNetworks developed the RTSP and PNA streaming protocols alongside the format for efficient network delivery. Compression in RM was considered impressive for its era, delivering watchable video at bit rates as low as 20-30 kbps when competing approaches struggled. While RealMedia has been largely replaced by modern streaming technologies, RM files remain in archives from the early internet era, including news organizations, educational institutions, and media libraries that adopted RealMedia during its peak popularity.
Developer: RealNetworks
Initial release: 1997
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 RM to AU?

AU is designed for Unix and Java applications. Extract audio from dying RM format into a purpose-built alternative.

What uses AU files?

Systems and applications built for Unix and Java applications accept AU as their native audio input format.

Is AU widely compatible?

AU is a specialized format. SOX and dedicated tools handle it; general media players may not.

Will quality be sufficient?

AU quality matches its intended purpose. Output depends on the quality of the RM source audio.

Can I batch convert?

Upload several RM files and extract AU audio from each simultaneously for efficient processing.