Secure Reliable Transport (SRT) Protocol

Introduction

Secure Reliable Transport (SRT) is an open source transport technology that optimizes streaming performance across unpredictable networks, such as the Internet.

Secure	Encrypts video streams
Reliable	Recovers from severe packet loss
Transport	Dynamically adapts to changing network conditions

SRT is applied to contribution and distribution endpoints as part of a video stream workflow to deliver the best quality and lowest latency video at all times.

As audio/video packets are streamed from a source to a destination device, SRT detects and adapts to the real-time network conditions between the two endpoints. SRT helps compensate for jitter and bandwidth fluctuations due to congestion over noisy networks, such as the Internet. Its error recovery mechanism minimizes the packet loss typical of Internet connections. And SRT supports AES encryption for end-to-end security, keeping your streams safe from prying eyes.

Join the conversation in the #development channel on Slack.

Guides

• SRT API Documents
• Using the srt-live-transmit App
• SRT Developer's Guide
• Contributing
• Reporting Issues
• SRT RFC: Latest IETF Draft, Latest Working Copy, GitHub Repo
• SRT CookBook: Website, GitHub Repo
• SRT Protocol Technical Overview
• Why SRT Was Created

Requirements

• C++03 (or above) compliant compiler.
• CMake 2.8.12 or above (as build system).
• OpenSSL 1.1 (to enable encryption, or build with -DENABLE_ENCRYPTION=OFF).
• Multithreading is provided by either of the following:
  • C++11: standard library (std by -DENABLE_STDCXX_SYNC=ON CMake option);
  • C++03: Pthreads (for POSIX systems it's built in, for Windows there is a ported library).
• Tcl 8.5 (optional, used by ./configure script or use CMake directly).

For a detailed description of the build system and options, please refer to SRT Build Options.

Build on Linux

Install cmake and openssl-devel (or similar name) package. For pthreads there should be -lpthreads linker flag added.

Default installation path prefix of make install is /usr/local.

To define a different installation path prefix, use the --prefix option with configure or -DCMAKE_INSTALL_PREFIX CMake option.

To uninstall, call make -n install to list all the dependencies, and then pass the list to rm.

Ubuntu 14

sudo apt-get update
sudo apt-get upgrade
sudo apt-get install tclsh pkg-config cmake libssl-dev build-essential
./configure
make

CentOS 7

sudo yum update
sudo yum install tcl pkgconfig openssl-devel cmake gcc gcc-c++ make automake
./configure
make

CentOS 6

sudo yum update
sudo yum install tcl pkgconfig openssl-devel cmake gcc gcc-c++ make automake
sudo yum install centos-release-scl-rh devtoolset-3-gcc devtoolset-3-gcc-c++
scl enable devtoolset-3 bash
./configure --use-static-libstdc++ --with-compiler-prefix=/opt/rh/devtoolset-3/root/usr/bin/
make

Build on Mac (Darwin, iOS)

Homebrew supports "srt" formula.

brew update
brew install srt

If you prefer using a head commit of master branch, you should add --HEAD option to brew command.

brew install --HEAD srt

Also, SRT can be built with cmake and make on Mac. Install cmake and openssl with development files from "brew". Note that the system version of OpenSSL is inappropriate, although you should be able to use any newer version compiled from sources, if you prefer.

brew install cmake
brew install openssl
export OPENSSL_ROOT_DIR=$(brew --prefix openssl)
export OPENSSL_LIB_DIR=$(brew --prefix openssl)"/lib"
export OPENSSL_INCLUDE_DIR=$(brew --prefix openssl)"/include"
./configure
make

Build on Windows

Follow the Building SRT for Windows instructions.