# Building FFmpeg on Windows
The script ffmpeg_build.sh allows compiling FFmpeg on Windows for the following targets :

  - Win32 using VS2015
  - Android arm/arm64/x86/x86_64 using CLANG

The script allows to build both release and debug versions of the library.

## Prerequisites

  - MSYS : http://www.mingw.org or MSYS2 (https://msys2.github.io/)
  - FFmpeg sources : get the sources of a release from https://github.com/FFmpeg/ (tested with 2.8.4)
  - YASM : http://yasm.tortall.net/Download.html (use a "Win32 .exe" release) (note : needs VC2010 redistributable)

Rename the YASM executable to yasm.exe and put in in your PATH.


## Building for Win32 with VS2013

### Prerequisites

  - C99-to-C89 : https://github.com/libav/c99-to-c89/releases
      Needed because VS only supports C99 from version 2013 onwards.
  - msinttypes : https://code.google.com/p/msinttypes/
      For inttypes.h and possibly stdint.h if your VS doesn't already have it.

Unzip C99-to-C89 and msinttypes to the same folder.
Add this folder to your PATH and INCLUDE variables (create INCLUDE if needed).

### Build

- Launch a Visual Studio shell (there should be a shortcut in your start menu).
For Windows 64bits exec : C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat x86_amd64
From this shell, launch an MSYS shell (msys32\msys2_shell.bat or msys32\msys2_shell.cmd -full-path)

- To initialise MSYS configuration the first time run the command:
$ pacman -Syu
$ pacman -S make

- Make sure cl and link point to VS executables (`which cl`, `which link`).
If it isn't the case for win32:
$ export "PATH=/c/Program Files (x86)/Microsoft Visual Studio 14.0/VC/bin:$PATH"
for win64:
$ export "PATH=/c/Program Files (x86)/Microsoft Visual Studio 14.0/VC/bin/x86_amd64:$PATH"

- You can now build FFmpeg (use absolute paths to specify directories) :
`./ffmpeg_build.sh <win32/win64> <debug/release> <ffmpeg sources dir> <build destination dir>`

Windows commands:
cd $SCOL_DEPENDENCIES_PATH/ffmpeg/sources
./ffmpeg_build.sh win32 release $SCOL_DEPENDENCIES_PATH/ffmpeg/sources/FFmpeg $SCOL_DEPENDENCIES_PATH/ffmpeg/sdk/windows/x86
./ffmpeg_build.sh win64 release $SCOL_DEPENDENCIES_PATH/ffmpeg/sources/FFmpeg $SCOL_DEPENDENCIES_PATH/ffmpeg/sdk/windows/x64

If the build fails because of mutliple int type declarations, remove stdint.h from the folder where you unpacked msinttypes.

*Note* : You can't link a debug Scol build with a release FFmpeg build, and vice versa.


## Building for Android

### Prerequisites

  - Android NDK (tested with 19b)
  - Make installed in MSYS

### Build

In an MSYS shell:
 $ cd $SCOL_DEPENDENCIES_PATH/ffmpeg/sources
 $ ./ffmpeg_build_android.sh
 
Or manually: 
  Use this command to add the binaries of the Android NDK to the PATH :
    export PATH="$ANDROID_NDK/toolchains/llvm/prebuilt/windowsx86-64/bin":$PATH

  Build FFmpeg with the desired options (use absolute paths to specify directories) :
    `./ffmpeg_build.sh android <debug/release> <ffmpeg sources dir> <build destination dir> <ANDROID_NDK_PATH> <ANDROID_TARGET_API> <ANDROID_TARGET_ABI> <OPENSSL_BASE_PATH>`

export PATH="$ANDROID_NDK/toolchains/llvm/prebuilt/windowsx86-64/bin":$PATH
cd $SCOL_DEPENDENCIES_PATH/ffmpeg/sources
./ffmpeg_build.sh android release $SCOL_DEPENDENCIES_PATH/ffmpeg/sources/FFmpeg $SCOL_DEPENDENCIES_PATH/ffmpeg/sdk/android/armeabi-v7a $ANDROID_NDK 19 armeabi-v7a $SCOL_DEPENDENCIES_PATH/sdk/android/armeabi-v7a
./ffmpeg_build.sh android release $SCOL_DEPENDENCIES_PATH/ffmpeg/sources/FFmpeg $SCOL_DEPENDENCIES_PATH/ffmpeg/sdk/android/arm64-v8a $ANDROID_NDK 21 arm64-v8a $SCOL_DEPENDENCIES_PATH/sdk/android/arm64-v8a
./ffmpeg_build.sh android release $SCOL_DEPENDENCIES_PATH/ffmpeg/sources/FFmpeg $SCOL_DEPENDENCIES_PATH/ffmpeg/sdk/android/x86 $ANDROID_NDK 19 x86 $SCOL_DEPENDENCIES_PATH/sdk/android/x86
./ffmpeg_build.sh android release $SCOL_DEPENDENCIES_PATH/ffmpeg/sources/FFmpeg $SCOL_DEPENDENCIES_PATH/ffmpeg/sdk/android/x86_64 $ANDROID_NDK 21 x86_64 $SCOL_DEPENDENCIES_PATH/sdk/android/x86_64