oRTP is a library implemeting Real-time Transport Protocol (RFC 3550), distributed under GNU GPLv2 or proprietary license.



  • Written in C, works under Linux (and probably any Unix) and Windows
  • Implement the RFC 3550 (RTP) with a easy to use API with high and low level access
  • Features an adaptive jitter algorithm for a receiver to adapt to the clockrate of the sender and network jitter
  • Includes support for multiples profiles, AV profile (RFC 3551) being the one by default
  • Supports part of RFC 4733 for telephone events over RTP
  • Includes an API to parse and compose RTCP packets, including AVPF RTCP packets
  • Features a congestion detector based on analysis of packet's arrival time
  • Comprises a download capacity estimator, usable for video streams



oRTP is dual licensed. It can be licensed and distributed:

  • under GPLv2 license since version 1.0.0 (previous versions are LGPLv2) - for free (open source)
  • under proprietary and commercial license to be used in closed source applications. Contact Belledonne Communications for costs and other service information.

Souce Code

Releases of source tar.gz are here.

Use git, read only access:

Project git


git clone git://git.linphone.org/ortp.git


Read API documentation.

The API is documented using doxygen