Opus

Not to be confused with the Opus-CBCS BBS software.

File Format
Name	Opus
Ontology	Electronic File Formats Audio and Music Opus

Opus is a lossy audio compression format designed by the Internet Engineering Task Force (IETF) for applications requiring high-quality, low-delay audio transmission (e.g. telephony or network music performance). It incorporates technology from Skype's SILK codec and Xiph.org's CELT codec.

Opus-coded audio is usually found inside an Ogg container (where it carries the extension .opus) or in a WebM container.

Information

• RFC 6716 - Definition of the Opus Audio Codec
• Ogg Encapsulation for the Opus Audio Codec (draft-ietf-codec-oggopus-00)
• RTP Payload Format for Opus Speech and Audio Codec (draft-spittka-payload-rtp-opus-03)
• Opus, the Swiss Army Knife of Audio Codecs (Presentation at linux.conf.au 2012]

Software

The Opus Codec downloads page contains opus-tools (encode / inspect / decode) .opus files and opusfile, an API for developers.

• foobar2000 can play back and encode Opus files (with the Free Encoder Pack
• SoX
• FFmpeg

Sample files

• dexvert samples — audio/opus
• https://github.com/xiph/opus-website/tree/master/static/examples

Links

• Bitstream conformance set
• The .opus test set (including intentionally malformed files)
• How Opus Came To Be

See Also

• CELT
• SILK