linphone
OSip
http://www.gnu.org/software/osip/
The GNU oSIP library is written in C and get no dependencies except the standard C library. oSIP is thread safe and will generally be used in a multi-threaded application. Nevertheless, this is optional.
oSIP is little in size and code and thus could be use to implement IP soft-phone as well as embedded SIP software. oSIP is not limited to endpoint agents, and can also be used to implement "SIP proxy".
oSIP does not intend to provide a high layer API for controlling "SIP Session" at this step. Instead, it currently provides an API for the SIP message parser, SDP message parser, and library to handle "SIP transactions" as defined by the SIP document.
exOsip
http://savannah.gnu.org/projects/exosip/
http://savannah.nongnu.org/projects/exosip
GPL. This is a new library based on oSIP. It contains a high layer easier to use for implementing SIP End point.
speex
Speex: A Free Codec For Free Speech
need use --prefix=/usr while ./configure(use ./confiure --help for more info)
Speex is based on CELP (CodeExcitedLinearPrediction) and is designed to compress voice at bitrates ranging from 2 to 44 kbps. Some of Speex's features include:
Narrowband (8 kHz), wideband (16 kHz), and ultra-wideband (32 kHz) compression in the same bitstream
- Intensity stereo encoding
- Packet loss concealment
- Variable bitrate operation (VBR)
- Voice Activity Detection (VAD)
- Discontinuous Transmission (DTX)
- Fixed-point port
- Acoustic echo canceller
- Noise suppression
ffmpeg
need use --prefix=/usr while ./configure(use ./confiure --help for more info)
FFmpeg is a complete, cross-platform solution to record, convert and stream audio and video. It includes libavcodec - the leading audio/video codec library.