Building Libwebm

To build libwebm you must first create project files. To do this run cmake
and pass it the path to your libwebm repo.

Makefile.unix can be used as a fallback on systems that cmake does not
support.


CMake Basics

To generate project/make files for the default toolchain on your system simply
run cmake with the path to the libwebm repo:

$ cmake path/to/libwebm

On Windows the above command will produce Visual Studio project files for the
newest Visual Studio detected on the system. On Mac OS X and Linux systems, the
above command will produce a makefile.

To control what types of projects are generated the -G parameter is added to
the cmake command line. This argument must be followed by the name of a
generator. Running cmake with the --help argument will list the available
generators for your system.

On Mac OS X you would run the following command to generate Xcode projects:

$ cmake path/to/libwebm -G Xcode

On a Windows box you would run the following command to generate Visual Studio
2013 projects:

$ cmake path/to/libwebm -G "Visual Studio 12"

To generate 64-bit Windows Visual Studio 2013 projects:

$ cmake path/to/libwebm "Visual Studio 12 Win64"


CMake Makefiles: Debugging and Optimization

Unlike Visual Studio and Xcode projects, the build configuration for make builds
is controlled when you run cmake. The following examples demonstrate various
build configurations.

Omitting the build type produces makefiles that use build flags containing
neither optimization nor debug flags:
$ cmake path/to/libwebm

A makefile using release (optimized) flags is produced like this:
$ cmake path/to/libwebm -DCMAKE_BUILD_TYPE=release

A release build with debug info can be produced as well:
$ cmake path/to/libwebm -DCMAKE_BUILD_TYPE=relwithdebinfo

And your standard debug build will be produced using:
$ cmake path/to/libwebm -DCMAKE_BUILD_TYPE=debug


Tests

To enable libwebm tests add -DENABLE_TESTS=ON CMake generation command line. For
example:

$ cmake path/to/libwebm -G Xcode -DENABLE_TESTS=ON

Libwebm tests depend on googletest. By default googletest is expected to be a
sibling directory of the Libwebm repository. To change that, update your CMake
command to be similar to the following:

$ cmake path/to/libwebm -G Xcode -DENABLE_TESTS=ON \
  -DGTEST_SRC_DIR=/path/to/googletest

The tests rely upon the LIBWEBM_TEST_DATA_PATH environment variable to locate
test input. The following example demonstrates running the muxer tests from the
build directory:

$ LIBWEBM_TEST_DATA_PATH=path/to/libwebm/testing/testdata ./muxer_tests

Note: Libwebm Googletest integration was built with googletest from
      https://github.com/google/googletest.git at git revision
      ddb8012eb48bc203aa93dcc2b22c1db516302b29.