oRTP is a library implemeting Real-time Transport Protocol (RFC3550), licensed under LGPL.



  • Written in C, works under Linux (and probably any Unix) and Windows.
  • Implement the RFC3550 (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.
  • Includes support for multiples profiles, AV profile (RFC3551) being the one by default.
  • Includes a packet scheduler for to send and recv packet "on time", according to their timestamp.
    Scheduling is optionnal, rtp sessions can remain not scheduled.
  • Supports mutiplexing IO, so that hundreds of RTP sessions can be scheduled by a single thread.
  • Supports part of RFC2833 for telephone events over RTP.
  • Includes an API to parse and compose RTCP packets, including AVPF RTCP packets.
  • The API is documented using doxygen
  • Licensed under the Lesser Gnu Public License.



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

  • under LGPL license - 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