General Documentation

Table of Contents

1. external libraries

FFmpeg can be hooked up with a number of external libraries to add support for more formats. None of them are used by default, their use has to be explicitly requested by passing the appropriate flags to ‘./configure’.

1.1 OpenCORE AMR

FFmpeg can make use of the OpenCORE libraries for AMR-NB decoding/encoding and AMR-WB decoding.

Go to http://sourceforge.net/projects/opencore-amr/ and follow the instructions for installing the libraries. Then pass --enable-libopencore-amrnb and/or --enable-libopencore-amrwb to configure to enable the libraries.

Note that OpenCORE is under the Apache License 2.0 (see http://www.apache.org/licenses/LICENSE-2.0 for details), which is incompatible with the LGPL version 2.1 and GPL version 2. You have to upgrade FFmpeg’s license to LGPL version 3 (or if you have enabled GPL components, GPL version 3) to use it.

2. Supported File Formats and Codecs

You can use the -formats and -codecs options to have an exhaustive list.

2.1 File Formats

FFmpeg supports the following file formats through the libavformat library:

X means that encoding (resp. decoding) is supported.

2.2 Image Formats

FFmpeg can read and write images for each frame of a video sequence. The following image formats are supported:

X means that encoding (resp. decoding) is supported.

E means that support is provided through an external library.

2.3 Video Codecs

X means that encoding (resp. decoding) is supported.

E means that support is provided through an external library.

2.4 Audio Codecs

X means that encoding (resp. decoding) is supported.

E means that support is provided through an external library.

I means that an integer-only version is available, too (ensures high performance on systems without hardware floating point support).

2.5 Subtitle Formats

X means that the feature is supported.

2.6 Network Protocols

X means that the protocol is supported.

2.7 Input/Output Devices

X means that input/output is supported.

3. Platform Specific information

3.1 DOS

Using a cross-compiler is preferred for various reasons.

3.1.1 DJGPP

FFmpeg cannot be compiled because of broken system headers, add --extra-cflags=-U__STRICT_ANSI__ to the configure options as a workaround.

3.2 OS/2

For information about compiling FFmpeg on OS/2 see http://www.edm2.com/index.php/FFmpeg.

3.3 Unix-like

Some parts of FFmpeg cannot be built with version 2.15 of the GNU assembler which is still provided by a few AMD64 distributions. To make sure your compiler really uses the required version of gas after a binutils upgrade, run:

$(gcc -print-prog-name=as) --version

If not, then you should install a different compiler that has no hard-coded path to gas. In the worst case pass --disable-asm to configure.

3.3.1 BSD

BSD make will not build FFmpeg, you need to install and use GNU Make (‘gmake’).

3.3.2 (Open)Solaris

GNU Make is required to build FFmpeg, so you have to invoke (‘gmake’), standard Solaris Make will not work. When building with a non-c99 front-end (gcc, generic suncc) add either --extra-libs=/usr/lib/values-xpg6.o or --extra-libs=/usr/lib/64/values-xpg6.o to the configure options since the libc is not c99-compliant by default. The probes performed by configure may raise an exception leading to the death of configure itself due to a bug in the system shell. Simply invoke a different shell such as bash directly to work around this:

bash ./configure

3.3.3 Darwin (MacOS X, iPhone)

MacOS X on PowerPC or ARM (iPhone) requires a preprocessor from http://github.com/yuvi/gas-preprocessor to build the optimized assembler functions. Just download the Perl script and put it somewhere in your PATH, FFmpeg’s configure will pick it up automatically.

3.4 Windows

To get help and instructions for building FFmpeg under Windows, check out the FFmpeg Windows Help Forum at http://ffmpeg.arrozcru.org/.

3.4.1 Native Windows compilation

FFmpeg can be built to run natively on Windows using the MinGW tools. Install the latest versions of MSYS and MinGW from http://www.mingw.org/. You can find detailed installation instructions in the download section and the FAQ.

FFmpeg does not build out-of-the-box with the packages the automated MinGW installer provides. It also requires coreutils to be installed and many other packages updated to the latest version. The minimum version for some packages are listed below:

• bash 3.1
• msys-make 3.81-2 (note: not mingw32-make)
• w32api 3.13
• mingw-runtime 3.15

FFmpeg automatically passes -fno-common to the compiler to work around a GCC bug (see http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37216).

Within the MSYS shell, configure and make with:

./configure --enable-memalign-hack
make
make install

This will install ‘ffmpeg.exe’ along with many other development files to ‘/usr/local’. You may specify another install path using the --prefix option in ‘configure’.

Notes:

• Building natively using MSYS can be sped up by disabling implicit rules in the Makefile by calling make -r instead of plain make. This speed up is close to non-existent for normal one-off builds and is only noticeable when running make for a second time (for example in make install).
• In order to compile FFplay, you must have the MinGW development library of SDL. Get it from http://www.libsdl.org. Edit the ‘bin/sdl-config’ script so that it points to the correct prefix where SDL was installed. Verify that ‘sdl-config’ can be launched from the MSYS command line.
• By using ./configure --enable-shared when configuring FFmpeg, you can build libavutil, libavcodec and libavformat as DLLs.

3.4.2 Microsoft Visual C++ compatibility

As stated in the FAQ, FFmpeg will not compile under MSVC++. However, if you want to use the libav* libraries in your own applications, you can still compile those applications using MSVC++. But the libav* libraries you link to must be built with MinGW. However, you will not be able to debug inside the libav* libraries, since MSVC++ does not recognize the debug symbols generated by GCC. We strongly recommend you to move over from MSVC++ to MinGW tools.

This description of how to use the FFmpeg libraries with MSVC++ is based on Microsoft Visual C++ 2005 Express Edition. If you have a different version, you might have to modify the procedures slightly.

3.4.2.1 Using static libraries

Assuming you have just built and installed FFmpeg in ‘/usr/local’.

1. Create a new console application ("File / New / Project") and then select "Win32 Console Application". On the appropriate page of the Application Wizard, uncheck the "Precompiled headers" option.
2. Write the source code for your application, or, for testing, just copy the code from an existing sample application into the source file that MSVC++ has already created for you. For example, you can copy ‘libavformat/output-example.c’ from the FFmpeg distribution.
3. Open the "Project / Properties" dialog box. In the "Configuration" combo box, select "All Configurations" so that the changes you make will affect both debug and release builds. In the tree view on the left hand side, select "C/C++ / General", then edit the "Additional Include Directories" setting to contain the path where the FFmpeg includes were installed (i.e. ‘c:\msys\1.0\local\include’). Do not add MinGW’s include directory here, or the include files will conflict with MSVC’s.
4. Still in the "Project / Properties" dialog box, select "Linker / General" from the tree view and edit the "Additional Library Directories" setting to contain the ‘lib’ directory where FFmpeg was installed (i.e. ‘c:\msys\1.0\local\lib’), the directory where MinGW libs are installed (i.e. ‘c:\mingw\lib’), and the directory where MinGW’s GCC libs are installed (i.e. ‘C:\mingw\lib\gcc\mingw32\4.2.1-sjlj’). Then select "Linker / Input" from the tree view, and add the files ‘libavformat.a’, ‘libavcodec.a’, ‘libavutil.a’, ‘libmingwex.a’, ‘libgcc.a’, and any other libraries you used (i.e. ‘libz.a’) to the end of "Additional Dependencies".
5. Now, select "C/C++ / Code Generation" from the tree view. Select "Debug" in the "Configuration" combo box. Make sure that "Runtime Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in the "Configuration" combo box and make sure that "Runtime Library" is set to "Multi-threaded DLL".
6. Click "OK" to close the "Project / Properties" dialog box.
7. MSVC++ lacks some C99 header files that are fundamental for FFmpeg. Get msinttypes from http://code.google.com/p/msinttypes/downloads/list and install it in MSVC++’s include directory (i.e. ‘C:\Program Files\Microsoft Visual Studio 8\VC\include’).
8. MSVC++ also does not understand the inline keyword used by FFmpeg, so you must add this line before #includeing libav*:

   #define inline _inline

9. Build your application, everything should work.

3.4.2.2 Using shared libraries

This is how to create DLL and LIB files that are compatible with MSVC++:

1. Add a call to ‘vcvars32.bat’ (which sets up the environment variables for the Visual C++ tools) as the first line of ‘msys.bat’. The standard location for ‘vcvars32.bat’ is ‘C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat’, and the standard location for ‘msys.bat’ is ‘C:\msys\1.0\msys.bat’. If this corresponds to your setup, add the following line as the first line of ‘msys.bat’:

   call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"

   Alternatively, you may start the ‘Visual Studio 2005 Command Prompt’, and run ‘c:\msys\1.0\msys.bat’ from there.

2. Within the MSYS shell, run lib.exe. If you get a help message from ‘Microsoft (R) Library Manager’, this means your environment variables are set up correctly, the ‘Microsoft (R) Library Manager’ is on the path and will be used by FFmpeg to create MSVC++-compatible import libraries.
3. Build FFmpeg with

   ./configure --enable-shared --enable-memalign-hack make make install

   Your install path (‘/usr/local/’ by default) should now have the necessary DLL and LIB files under the ‘bin’ directory.

To use those files with MSVC++, do the same as you would do with the static libraries, as described above. But in Step 4, you should only need to add the directory where the LIB files are installed (i.e. ‘c:\msys\usr\local\bin’). This is not a typo, the LIB files are installed in the ‘bin’ directory. And instead of adding the static libraries (‘libxxx.a’ files) you should add the MSVC import libraries (‘avcodec.lib’, ‘avformat.lib’, and ‘avutil.lib’). Note that you should not use the GCC import libraries (‘libxxx.dll.a’ files), as these will give you undefined reference errors. There should be no need for ‘libmingwex.a’, ‘libgcc.a’, and ‘wsock32.lib’, nor any other external library statically linked into the DLLs. The ‘bin’ directory contains a bunch of DLL files, but the ones that are actually used to run your application are the ones with a major version number in their filenames (i.e. ‘avcodec-51.dll’).

FFmpeg headers do not declare global data for Windows DLLs through the usual dllexport/dllimport interface. Such data will be exported properly while building, but to use them in your MSVC++ code you will have to edit the appropriate headers and mark the data as dllimport. For example, in libavutil/pixdesc.h you should have:

extern __declspec(dllimport) const AVPixFmtDescriptor av_pix_fmt_descriptors[];

Note that using import libraries created by dlltool requires the linker optimization option to be set to "References: Keep Unreferenced Data (/OPT:NOREF)", otherwise the resulting binaries will fail during runtime. This isn’t required when using import libraries generated by lib.exe.

3.4.3 Cross compilation for Windows with Linux

You must use the MinGW cross compilation tools available at http://www.mingw.org/.

Then configure FFmpeg with the following options:

./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-

(you can change the cross-prefix according to the prefix chosen for the MinGW tools).

Then you can easily test FFmpeg with Wine (http://www.winehq.com/).

3.4.4 Compilation under Cygwin

Please use Cygwin 1.7.x as the obsolete 1.5.x Cygwin versions lack llrint() in its C library.

Install your Cygwin with all the "Base" packages, plus the following "Devel" ones:

binutils, gcc4-core, make, git, mingw-runtime, texi2html

And the following "Utils" one:

diffutils

Then run

./configure --enable-static --disable-shared

to make a static build.

The current gcc4-core package is buggy and needs this flag to build shared libraries:

./configure --enable-shared --disable-static --extra-cflags=-fno-reorder-functions

If you want to build FFmpeg with additional libraries, download Cygwin "Devel" packages for Ogg and Vorbis from any Cygwin packages repository:

libogg-devel, libvorbis-devel

These library packages are only available from Cygwin Ports (http://sourceware.org/cygwinports/) :

yasm, libSDL-devel, libdirac-devel, libfaac-devel, libgsm-devel,
libmp3lame-devel, libschroedinger1.0-devel, speex-devel, libtheora-devel,
libxvidcore-devel

The recommendation for libnut and x264 is to build them from source by yourself, as they evolve too quickly for Cygwin Ports to be up to date.

Cygwin 1.7.x has IPv6 support. You can add IPv6 to Cygwin 1.5.x by means of the libgetaddrinfo-devel package, available at Cygwin Ports.

3.4.5 Crosscompilation for Windows under Cygwin

With Cygwin you can create Windows binaries that do not need the cygwin1.dll.

Just install your Cygwin as explained before, plus these additional "Devel" packages:

gcc-mingw-core, mingw-runtime, mingw-zlib

and add some special flags to your configure invocation.

For a static build run

./configure --target-os=mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin

and for a build with shared libraries

./configure --target-os=mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin

This document was generated by Kyle Schwarz on May 18, 2011 using texi2html 1.82.