Speex: A Free Codec For Free Speech
It provides a free solution for speech transmission in communication applications, but is incremental as it builds on existing CELP technology.
The paper introduces Speex, a free, open-source speech codec developed since 2002 to transmit speech over low-latency, unreliable packet networks, based on the CELP algorithm and optimized for applications like communication.
The Speex project has been started in 2002 to address the need for a free, open-source speech codec. Speex is based on the Code Excited Linear Prediction (CELP) algorithm and, unlike the previously existing Vorbis codec, is optimised for transmitting speech for low latency communication over an unreliable packet network. This paper presents an overview of Speex, the technology involved in it and how it can be used in applications. The most recent developments in Speex, such as the fixed-point port, acoustic echo cancellation and noise suppression are also addressed.