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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 --disable-asm
to configure.
If you compiled Libav libraries statically and you want to use them to
build your own shared library, you may need to force PIC support (with
--enable-pic during Libav configure) and add the following option
to your project LDFLAGS:
-Wl,-Bsymbolic |
If your target platform requires position independent binaries, you should
pass the correct linking flag (e.g. -pie) to --extra-ldexeflags.
BSD make will not build Libav, you need to install and use GNU Make
(gmake).
GNU Make is required to build Libav, 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 |
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 assembly functions. Put the Perl script somewhere in your PATH, Libav's configure will pick it up automatically.
OS X on AMD64 and x86 requires yasm to build most of the
optimized assembly functions Homebrew,
Gentoo Prefix
or MacPorts can easily provide it.
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.
Notes:
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 during
make install).
pkg-config installed.
./configure --enable-shared when configuring Libav,
you can build all libraries as DLLs.
Libav can be built with MSVC 2012 or earlier using a C99-to-C89 conversion utility and wrapper, or with MSVC 2013 and ICL natively.
You will need the following prerequisites:
To set up a proper environment in MSYS, you need to run msys.bat from
the Visual Studio or Intel Compiler command prompt.
Place yasm.exe somewhere in your PATH. If using MSVC 2012 or
earlier, place c99wrap.exe and c99conv.exe somewhere in your
PATH as well.
Next, make sure any other headers and libs you want to use, such as zlib, are
located in a spot that the compiler can see. Do so by modifying the LIB
and INCLUDE environment variables to include the Windows-style
paths to these directories. Alternatively, you can try and use the
--extra-cflags/--extra-ldflags configure options. If using MSVC
2012 or earlier, place inttypes.h somewhere the compiler can see too.
Finally, run:
For MSVC: ./configure --toolchain=msvc For ICL: ./configure --toolchain=icl make make install |
If you wish to compile shared libraries, add --enable-shared to your
configure options. Note that due to the way MSVC and ICL handle 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.
Notes:
link.exe conflicts with MSVC's linker.
You can find out by running which link to see which link.exe you
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.exe takes precedence in your PATH over coreutils'.
zlib.lib with MSVC. Regardless of which method you use, you must still
follow step 3, or compilation will fail.
win32/Makefile.msc so that it uses -MT instead of -MD, since
this is how Libav is built as well.
zconf.h and remove its inclusion of unistd.h. This gets
erroneously included when building Libav.
nmake -f win32/Makefile.msc.
zlib.lib, zconf.h, and zlib.h to somewhere MSVC
can see.
Anything else is not officially supported.
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.
You will 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
set References to 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 lib.exe.
This issue is reported upstream at
http://sourceware.org/bugzilla/show_bug.cgi?id=12633.
To create import libraries that work with the /OPT:REF option
(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.exe:
lib /machine:i386 /def:..\lib\foo-version.def /out:foo.lib |
Replace foo-version and 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:
bc, diffutils |
If you want to build Libav 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:
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.
Working packages of these tools can be found at
ports2plan9.
They can be installed with 9front's pkg
utility by setting pkgpath to
http://ports2plan9.googlecode.com/files/.
head and printf commands
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.
stdint.h and inttypes.h
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
ports2plan9
includes an updated C library, but installing the full package gives
unusable executables. Instead, keep the files from gccbin.tgz
under /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:
strerror.o
strtoll.o
snprintf.o
vsnprintf.o
vfprintf.o
_IO_getc.o
_IO_putc.o
Use the --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.
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