FreeSWITCH Documentation

ExprEval is a high-performance C-based expression evaluation library with a C++ wrapper. It is designed to parse and evaluate expressions containing variables, constants, and functions.

Key features:

• Multiple Expressions: Supports parsing multiple expressions in a single string, provided each sub-expression ends with a semicolon (;).
• Performance: Expressions are parsed into an action tree first, allowing the same expression to be evaluated many times efficiently.
• Shared Resources: Functions, constants, and variables are stored in separate lists that can be shared across multiple expression objects to reduce memory overhead and allow inter-expression dependency.

libSRTP is an implementation of the Secure Real-time Transport Protocol (SRTP), the Universal Security Transform (UST), and a supporting cryptographic kernel. It provides functions to protect RTP and RTCP data by providing confidentiality to RTP data and authentication to the RTP header and payload (as defined in RFC 3711).

Key components include:

• SRTP API: Documented in include/srtp.h.
• Library File: libsrtp2.a after compilation.
• srtp_stream_t: An opaque typedef pointing to a structure holding the state for an SRTP stream (keys, cipher/authentication parameters, and anti-replay data).
• srtp_t: An opaque typedef pointing to a structure holding the state for an entire SRTP session, which can contain multiple stream contexts.

libyuv relies on two core formats for its primary operations:

• I420: The core YUV format. All YUV formats can be converted to or from I420.
• ARGB: The core RGB format. All RGB formats can be converted to or from ARGB.

Filtering functions (such as scaling) and planar functions are designed to work specifically on I420 and/or ARGB. When performing conversions, function names typically follow the pattern [Source]To[Destination], such as I420ToARGB().

You can access the FreeSWITCH community and professional support through the following channels:

• IRC: #freeswitch on irc.freenode.net
• Mailing List: freeswitch-users on lists.freeswitch.org
• Professional Consulting: Visit freeswitchsolutions.com or email consulting@freeswitch.org.

To detect memory address errors, build with build_for_tool=asan and run the resulting unittests using Valgrind.

GYP_DEFINES="clang=0 target_arch=x64 build_for_tool=asan" python gyp_libyuv
ninja -C out/Debug
valgrind out/Debug/libyuv_unittest

Use gn to generate build files and ninja to compile for Release and Debug builds.

gn gen out/Release "--args=is_debug=false"
gn gen out/Debug "--args=is_debug=true"
ninja -v -C out/Release
ninja -v -C out/Debug

On Windows, you can use CMake to generate Visual Studio project files. Ensure you run these commands from within a Visual Studio command prompt or after running vcvarsall.bat.

# Create build subdirectory
mkdir build
cd build

# Make project files
cmake .. -G "Visual Studio 15 2017"

# Or for 64 bit project files
cmake .. -G "Visual Studio 15 2017 Win64"

To build a custom container, you must first generate a minimized archive of the FreeSWITCH files using the provided scripts. This requires a Debian-based distribution.

1. Install the vanilla configuration package: apt-get install freeswitch-conf-vanilla
2. Clone the FreeSWITCH repository.
3. Run the make_min_archive.sh script located in freeswitch/docker/base_image.
4. Build the image using docker build.

To build GoogleTest and GoogleMock as a standalone project using CMake, follow these steps:

1. Clone the repository and enter the directory.
2. Create a build directory.
3. Run CMake to generate build scripts.
4. Build using make (on *nix) or a Visual Studio/Xcode project file (on Windows/macOS).

To build only GoogleTest without GoogleMock, pass -DBUILD_GMOCK=OFF to the cmake command.

git clone https://github.com/google/googletest.git -b release-1.10.0
cd googletest
mkdir build
cd build
cmake .. -DBUILD_GMOCK=OFF
make