Speex

File Format
Name	Speex
Ontology	Electronic File Formats Audio and Music Speex
Extension(s)	.spx
MIME Type(s)	audio/ogg
LoCFDD	fdd000259, fdd000260
PRONOM	fmt/948

Description

Speex is an open-source audio compression format designed for speech. While the Speex codec and source is still available, it has been obsoleted by the Opus codec.

Speex could be distributed as a single stream (where it normally was given .spx extension in the event being saved to disk), and inside an Ogg container.

Information

• The Speex Codec Manual Version 1.2 Beta 3
• Speex Reference Manual 1.2-beta2
• RFC 5574 - RTP Payload Format for the Speex Codec
• Speex source

Software

• FFmpeg
• The latest source and binary releases of Speex are available here.
• Software supporting Speex can be found here.

Sample files

• dexvert samples — audio/speex
• A sample .spx file can be found here

Links

• Speex samples (decoded back to WAV format)