libre is a generic library for real-time communications with asynchronous I/O support. It is written in portable POSIX source code that conforms to the ANSI C89 and ISO C99 standards. It is robust and fast, with a low memory footprint. It also features RFC compliance and support for IPv4 and IPv6. Protocol implementations include SIP, SDP, RTP/RTCP, BFCP, DNS, STUN/TURN/ICE, HTTP, and WebSockets.
baresip is a bare-bones SIP user agent. It supports SIP, SDP, RTP/RTCP, and STUN/TURN/ICE, and IPv4 and IPv6, and is RFC-compliant and has portable C89 and C99 source code. A modular plugin architecture provides stdio, cons, and evdev user interfaces, celt, g711, g722, gsm, ilbc, l16, and speex audio codecs, alsa, coreaudio, gst, portaudio, oss, winwav, and mda audio drivers, speex_pp, speex_aec, speex_resamp, and sndfile audio filters, the avcodec video codec, avformat, quicktime, qtcapture, v4l, and v4l2 video sources, sdl, opengl, and x11 video display drivers, and srtp media encoding.
RTSPdump is a tool for downloading a multimedia stream from a Windows Media server (WMServer). It accepts rtsp:// and mms:// URLs. It supports both UDP and TCP traffic. The stream can be saved into a WMV file for archiving or timeshifting purposes or passed through stdout to another program for processing or immediate viewing. It has also limited support for other brands of servers that also provide RTSP streaming.
DVBlast is a simple and powerful MPEG-2 transport stream demux and streaming application with several input methods, such as Linux DVB supported cards (DVB-S, DVB-S2, DVB-C, DVB-T, etc.), ASI cards, and UDP/RTP streams carrying a transport stream. It outputs one or several UDP/RTP streams carrying transport streams with hardware or software PID filtering, PID-based or service-based demultiplexing, and optional descrambling via a CAM device.
Scenic is a free software suite for streaming audio, video, and MIDI between live events. It was created at the Society for Arts and Technology (SAT) to give artists a powerful tool for telepresence in live arts contexts, and new media installations. The streaming is done over RTP with the GStreamer multimedia framework. Users can also choose low-bandwidth or high-quality codecs, depending on what is available on their system. It offers up to as many audio channels as your audio device supports. It consists of a desktop application and several command-line utilities: scenic (a Desktop application to stream audio, video, and MIDI over RTP); milhouse (streams audio and video over RTP); midistream (streams MIDI notes and controls over RTP); dc-ctl (controls connected DC IEEE 1394 cameras); firereset (resets an IEEE 1394 bus to help in case of problems); and jack-info (prints information about running JACK servers).
Jingle Nodes is a relay auto-discovery service that provides Jingle Relay Type Candidates that can be used in ICE-UDP and also on RAW-UDP Jingle sessions. Relay candidates can provide NAT traversal for users who don't have STUN/TURN Support, but also for users with STUN/TURN support for whom negotiation failed. It is designed to allow you to communicate freely with your friends without being attached to closed service providers like Skype or telecommunications carriers.