WebM Codec SDK: README

WebM Codec SDK

README

    README - 9 January 2017

    Welcome to the WebM VP8/VP9 Codec SDK!

    COMPILING THE APPLICATIONS/LIBRARIES:
      The build system used is similar to autotools. Building generally consists of
      "configuring" with your desired build options, then using GNU make to build
      the application.

      1. Prerequisites

        * All x86 targets require the Yasm[1] assembler be installed.
        * All Windows builds require that Cygwin[2] be installed.
        * Building the documentation requires Doxygen[3]. If you do not
          have this package, the install-docs option will be disabled.
        * Downloading the data for the unit tests requires curl[4] and sha1sum.
          sha1sum is provided via the GNU coreutils, installed by default on
          many *nix platforms, as well as MinGW and Cygwin. If coreutils is not
          available, a compatible version of sha1sum can be built from
          source[5]. These requirements are optional if not running the unit
          tests.

        [1]: http://www.tortall.net/projects/yasm
        [2]: http://www.cygwin.com
        [3]: http://www.doxygen.org
        [4]: http://curl.haxx.se
        [5]: http://www.microbrew.org/tools/md5sha1sum/

      2. Out-of-tree builds
      Out of tree builds are a supported method of building the application. For
      an out of tree build, the source tree is kept separate from the object
      files produced during compilation. For instance:

        $ mkdir build
        $ cd build
        $ ../libvpx/configure <options>
        $ make

      3. Configuration options
      The 'configure' script supports a number of options. The --help option can be
      used to get a list of supported options:
        $ ../libvpx/configure --help

      4. Cross development
      For cross development, the most notable option is the --target option. The
      most up-to-date list of supported targets can be found at the bottom of the
      --help output of the configure script. As of this writing, the list of
      available targets is:

        arm64-android-gcc
        arm64-darwin-gcc
        arm64-linux-gcc
        armv7-android-gcc
        armv7-darwin-gcc
        armv7-linux-rvct
        armv7-linux-gcc
        armv7-none-rvct
        armv7-win32-vs11
        armv7-win32-vs12
        armv7-win32-vs14
        armv7s-darwin-gcc
        armv8-linux-gcc
        mips32-linux-gcc
        mips64-linux-gcc
        sparc-solaris-gcc
        x86-android-gcc
        x86-darwin8-gcc
        x86-darwin8-icc
        x86-darwin9-gcc
        x86-darwin9-icc
        x86-darwin10-gcc
        x86-darwin11-gcc
        x86-darwin12-gcc
        x86-darwin13-gcc
        x86-darwin14-gcc
        x86-darwin15-gcc
        x86-iphonesimulator-gcc
        x86-linux-gcc
        x86-linux-icc
        x86-os2-gcc
        x86-solaris-gcc
        x86-win32-gcc
        x86-win32-vs10
        x86-win32-vs11
        x86-win32-vs12
        x86-win32-vs14
        x86_64-android-gcc
        x86_64-darwin9-gcc
        x86_64-darwin10-gcc
        x86_64-darwin11-gcc
        x86_64-darwin12-gcc
        x86_64-darwin13-gcc
        x86_64-darwin14-gcc
        x86_64-darwin15-gcc
        x86_64-iphonesimulator-gcc
        x86_64-linux-gcc
        x86_64-linux-icc
        x86_64-solaris-gcc
        x86_64-win64-gcc
        x86_64-win64-vs10
        x86_64-win64-vs11
        x86_64-win64-vs12
        x86_64-win64-vs14
        generic-gnu

      The generic-gnu target, in conjunction with the CROSS environment variable,
      can be used to cross compile architectures that aren't explicitly listed, if
      the toolchain is a cross GNU (gcc/binutils) toolchain. Other POSIX toolchains
      will likely work as well. For instance, to build using the mipsel-linux-uclibc
      toolchain, the following command could be used (note, POSIX SH syntax, adapt
      to your shell as necessary):

        $ CROSS=mipsel-linux-uclibc- ../libvpx/configure

      In addition, the executables to be invoked can be overridden by specifying the
      environment variables: CC, AR, LD, AS, STRIP, NM. Additional flags can be
      passed to these executables with CFLAGS, LDFLAGS, and ASFLAGS.

      5. Configuration errors
      If the configuration step fails, the first step is to look in the error log.
      This defaults to config.log. This should give a good indication of what went
      wrong. If not, contact us for support.

    VP8/VP9 TEST VECTORS:
      The test vectors can be downloaded and verified using the build system after
      running configure. To specify an alternate directory the
      LIBVPX_TEST_DATA_PATH environment variable can be used.

      $ ./configure --enable-unit-tests
      $ LIBVPX_TEST_DATA_PATH=../libvpx-test-data make testdata

    CODE STYLE:
      The coding style used by this project is enforced with clang-format using the
      configuration contained in the .clang-format file in the root of the
      repository.

      Before pushing changes for review you can format your code with:
      # Apply clang-format to modified .c, .h and .cc files
      $ clang-format -i --style=file \
        $(git diff --name-only --diff-filter=ACMR '*.[hc]' '*.cc')

      Check the .clang-format file for the version used to generate it if there is
      any difference between your local formatting and the review system.

      See also: http://clang.llvm.org/docs/ClangFormat.html

    SUPPORT
      This library is an open source project supported by its community. Please
      email webm-discuss@webmproject.org for help.