Some parts of Libav 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
BSD make will not build Libav, you need to install and use GNU Make
GNU Make is required to build Libav, so you have to invoke (
standard Solaris Make will not work. When building with a non-c99 front-end
(gcc, generic suncc) add either
--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:
The toolchain provided with Xcode is sufficient to build the basic unacelerated code.
OS X on PowerPC or ARM (iPhone) requires a preprocessor from git://git.libav.org/gas-preprocessor.git to build the optimized assembler functions. Put the Perl script somewhere in your PATH, Libav’s configure will pick it up automatically.
Using a cross-compiler is preferred for various reasons. http://www.delorie.com/howto/djgpp/linux-x-djgpp.html
For information about compiling Libav on OS/2 see http://www.edm2.com/index.php/FFmpeg.
Libav can be built to run natively on Windows using the MinGW or MinGW-w64 toolchains. Install the latest versions of MSYS and MinGW or MinGW-w64 from http://www.mingw.org/ or http://mingw-w64.sourceforge.net/. You can find detailed installation instructions in the download section and the FAQ.
make -rinstead 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 during
./configure --enable-sharedwhen configuring Libav, you can build all libraries as DLLs.
Libav can be built with MSVC using a C99-to-C89 conversion utility and wrapper.
You will need the following prerequisites:
To set up a proper MSVC environment in MSYS, you simply need to run
msys.bat from the Visual Studio command prompt.
somewhere in your
Next, make sure
inttypes.h and any other headers and libs you want to use
are located in a spot that MSVC can see. Do so by modifying the
INCLUDE environment variables to include the Windows paths to
these directories. Alternatively, you can try and use the
--extra-ldflags configure options.
./configure --toolchain=msvc make make install
If you wish to compile shared libraries, add
--enable-shared to your
configure options. Note that due to the way MSVC handles DLL imports and
exports, you cannot compile static and shared libraries at the same time, and
enabling shared libraries will automatically disable the static ones.
link.execonflicts with MSVC’s linker. You can find out by running
which linkto see which
link.exeyou are using. If it is located at
/bin/link.exe, then you have the wrong one in your
PATH. Either move or remove that copy, or make sure MSVC’s
link.exetakes precedence in your
zlib.libwith MSVC. Regardless of which method you use, you must still follow step 3, or compilation will fail.
win32/Makefile.mscso that it uses -MT instead of -MD, since this is how Libav is built as well.
zconf.hand remove its inclusion of
unistd.h. This gets erroneously included when building Libav.
nmake -f win32/Makefile.msc.
zlib.hto somewhere MSVC can see.
If you plan to link with MSVC-built static libraries, you will need
to make sure you have
Runtime Library set to
Multi-threaded (/MT) in your project’s settings.
Libav 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;
You will also need to define
inline to something MSVC understands:
#define inline __inline
Also note, that as stated in Microsoft Visual C++, you will need an MSVC-compatible inttypes.h.
If you plan on using import libraries created by dlltool, you must
No (/OPT:NOREF) under the linker optimization
settings, otherwise the resulting binaries will fail during runtime.
This is not required when using import libraries generated by
This issue is reported upstream at
To create import libraries that work with the
(which is enabled by default in Release mode), follow these steps:
Alternatively, in a normal command line prompt, call ‘vcvars32.bat’ which sets up the environment variables for the Visual C++ tools (the standard location for this file is something like ‘C:\Program Files (x86_\Microsoft Visual Studio 10.0\VC\bin\vcvars32.bat’).
lib /machine:i386 /def:..\lib\foo-version.def /out:foo.lib
foo with the respective library names.
You must use the MinGW cross compilation tools available at http://www.mingw.org/.
Then configure Libav 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 Libav with Wine.
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
In order to run FATE you will also need the following "Utils" packages:
If you want to build Libav with additional libraries, download Cygwin "Devel" packages for Ogg and Vorbis from any Cygwin packages repository:
These library packages are only available from Cygwin Ports:
yasm, libSDL-devel, libfaac-devel, libgsm-devel, libmp3lame-devel, libschroedinger1.0-devel, speex-devel, libtheora-devel, libxvidcore-devel
The recommendation for x264 is to build it from source, as it evolves too quickly for Cygwin Ports to be up to date.
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 --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
and for a build with shared libraries
./configure --target-os=mingw32 --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
The native Plan 9 compiler does not implement all the C99 features needed by Libav so the gcc port must be used. Furthermore, a few items missing from the C library and shell environment need to be fixed.
Replacements adequate for building Libav can be found in the
compat/plan9 directory. Place these somewhere they will be
found by the shell. These are not full implementations of the
commands and are not suitable for general use.
Replacement headers are available from http://code.google.com/p/plan9front/issues/detail?id=152.
Some functions in the C library are missing or incomplete. The
gcc-apelibs-1207 package from
includes an updated C library, but installing the full package gives
unusable executables. Instead, keep the files from
/386/lib/gnu. From the
libc.a archive in the
gcc-apelibs-1207 package, extract the following object files and
turn them into a library:
--extra-libs option of
configure to inform the
build system of this library.
Unlike most other systems, Plan 9 enables FPU exceptions by default. These must be disabled before calling any Libav functions. While the included tools will do this automatically, other users of the libraries must do it themselves.