doc: split platform specific information

Move the platform-specific information in its own file.

3 files changed, 360 insertions, 346 deletions

diff --git a/doc/Makefile b/doc/Makefile
index 3ff4417cfb..0acd9844af 100644
--- a/doc/Makefile
+++ b/doc/Makefile
@@ -7,6 +7,7 @@ HTMLPAGES   = $(PROGS-yes:%=doc/%.html)                                 \
               doc/general.html                                          \
               doc/git-howto.html                                        \
               doc/libavfilter.html                                      \
+              doc/platform.html                                         \
 
 DOCS = $(HTMLPAGES) $(MANPAGES) $(PODPAGES)
 
diff --git a/doc/general.texi b/doc/general.texi
index 451aed1308..17c0229661 100644
--- a/doc/general.texi
+++ b/doc/general.texi
@@ -763,350 +763,4 @@ performance on systems without hardware floating point support).
 
 @code{X} means that input/output is supported.
 
-
-@chapter Platform Specific information
-
-@section DOS
-
-Using a cross-compiler is preferred for various reasons.
-
-@section OS/2
-
-For information about compiling Libav on OS/2 see
-@url{http://www.edm2.com/index.php/FFmpeg}.
-
-@section Unix-like
-
-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:
-
-@example
-$(gcc -print-prog-name=as) --version
-@end example
-
-If not, then you should install a different compiler that has no
-hard-coded path to gas. In the worst case pass @code{--disable-asm}
-to configure.
-
-@subsection BSD
-
-BSD make will not build Libav, you need to install and use GNU Make
-(@file{gmake}).
-
-@subsection (Open)Solaris
-
-GNU Make is required to build Libav, so you have to invoke (@file{gmake}),
-standard Solaris Make will not work. When building with a non-c99 front-end
-(gcc, generic suncc) add either @code{--extra-libs=/usr/lib/values-xpg6.o}
-or @code{--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:
-
-@example
-bash ./configure
-@end example
-
-@anchor{Darwin}
-@subsection Darwin (OSX, iPhone)
-
-The toolchain provided with Xcode is sufficient to build the basic
-unacelerated code.
-
-OSX on PowerPC or ARM (iPhone) requires a preprocessor from
-@url{http://github.com/yuvi/gas-preprocessor} to build the optimized
-assembler functions. Just download the Perl script and put it somewhere
-in your PATH, Libav's configure will pick it up automatically.
-
-OSX on amd64 and x86 requires @command{yasm} to build most of the
-optimized assembler functions @url{http://mxcl.github.com/homebrew/, Homebrew},
-@url{http://www.gentoo.org/proj/en/gentoo-alt/prefix/bootstrap-macos.xml, Gentoo Prefix}
-or @url{http://www.macports.org, MacPorts} can easily provide it.
-
-@section Windows
-
-@subsection Native Windows compilation
-
-Libav can be built to run natively on Windows using the MinGW tools. Install
-the latest versions of MSYS and MinGW from @url{http://www.mingw.org/}.
-You can find detailed installation
-instructions in the download section and the FAQ.
-
-Libav 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:
-
-@itemize
-@item bash 3.1
-@item msys-make 3.81-2 (note: not mingw32-make)
-@item w32api 3.13
-@item mingw-runtime 3.15
-@end itemize
-
-Libav automatically passes @code{-fno-common} to the compiler to work around
-a GCC bug (see @url{http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37216}).
-
-Notes:
-
-@itemize
-
-@item Building natively using MSYS can be sped up by disabling implicit rules
-in the Makefile by calling @code{make -r} instead of plain @code{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
-@code{make install}).
-
-@item In order to compile AVplay, you must have the MinGW development library
-of @uref{http://www.libsdl.org/, SDL}.
-Edit the @file{bin/sdl-config} script so that it points to the correct prefix
-where SDL was installed. Verify that @file{sdl-config} can be launched from
-the MSYS command line.
-
-@item By using @code{./configure --enable-shared} when configuring Libav,
-you can build libavutil, libavcodec and libavformat as DLLs.
-
-@end itemize
-
-@subsection Microsoft Visual C++ compatibility
-
-As stated in the FAQ, Libav 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 @emph{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 Libav 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.
-
-@subsubsection Using static libraries
-
-Assuming you have just built and installed Libav in @file{/usr/local}.
-
-@enumerate
-
-@item 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.
-
-@item 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
-@file{libavformat/output-example.c} from the Libav distribution.
-
-@item 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 Libav includes were
-installed (i.e. @file{c:\msys\1.0\local\include}).
-Do not add MinGW's include directory here, or the include files will
-conflict with MSVC's.
-
-@item Still in the "Project / Properties" dialog box, select
-"Linker / General" from the tree view and edit the
-"Additional Library Directories" setting to contain the @file{lib}
-directory where Libav was installed (i.e. @file{c:\msys\1.0\local\lib}),
-the directory where MinGW libs are installed (i.e. @file{c:\mingw\lib}),
-and the directory where MinGW's GCC libs are installed
-(i.e. @file{C:\mingw\lib\gcc\mingw32\4.2.1-sjlj}). Then select
-"Linker / Input" from the tree view, and add the files @file{libavformat.a},
-@file{libavcodec.a}, @file{libavutil.a}, @file{libmingwex.a},
-@file{libgcc.a}, and any other libraries you used (i.e. @file{libz.a})
-to the end of "Additional Dependencies".
-
-@item 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".
-
-@item Click "OK" to close the "Project / Properties" dialog box.
-
-@item MSVC++ lacks some C99 header files that are fundamental for Libav.
-Get msinttypes from @url{http://code.google.com/p/msinttypes/downloads/list}
-and install it in MSVC++'s include directory
-(i.e. @file{C:\Program Files\Microsoft Visual Studio 8\VC\include}).
-
-@item MSVC++ also does not understand the @code{inline} keyword used by
-Libav, so you must add this line before @code{#include}ing libav*:
-@example
-#define inline _inline
-@end example
-
-@item Build your application, everything should work.
-
-@end enumerate
-
-@subsubsection Using shared libraries
-
-This is how to create DLL and LIB files that are compatible with MSVC++:
-
-Within the MSYS shell, build Libav with
-
-@example
-./configure --enable-shared
-make
-make install
-@end example
-
-Your install path (@file{/usr/local/} by default) should now have the
-necessary DLL and LIB files under the @file{bin} directory.
-
-Alternatively, build the libraries with a cross compiler, according to
-the instructions below in @ref{Cross compilation for Windows with Linux}.
-
-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. @file{c:\msys\usr\local\bin}). This is not a typo, the LIB files are
-installed in the @file{bin} directory. And instead of adding the static
-libraries (@file{libxxx.a} files) you should add the MSVC import libraries
-(@file{avcodec.lib}, @file{avformat.lib}, and
-@file{avutil.lib}). Note that you should not use the GCC import
-libraries (@file{libxxx.dll.a} files), as these will give you undefined
-reference errors. There should be no need for @file{libmingwex.a},
-@file{libgcc.a}, and @file{wsock32.lib}, nor any other external library
-statically linked into the DLLs.
-
-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:
-@example
-extern __declspec(dllimport) const AVPixFmtDescriptor av_pix_fmt_descriptors[];
-@end example
-
-Note that using import libraries created by dlltool requires
-the linker optimization option to be set to
-"References: Keep Unreferenced Data (@code{/OPT:NOREF})", otherwise
-the resulting binaries will fail during runtime. This isn't
-required when using import libraries generated by lib.exe.
-This issue is reported upstream at
-@url{http://sourceware.org/bugzilla/show_bug.cgi?id=12633}.
-
-To create import libraries that work with the @code{/OPT:REF} option
-(which is enabled by default in Release mode), follow these steps:
-
-@enumerate
-
-@item Open @file{Visual Studio 2005 Command Prompt}.
-
-Alternatively, in a normal command line prompt, call @file{vcvars32.bat}
-which sets up the environment variables for the Visual C++ tools
-(the standard location for this file is
-@file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat}).
-
-@item Enter the @file{bin} directory where the created LIB and DLL files
-are stored.
-
-@item Generate new import libraries with @file{lib.exe}:
-
-@example
-lib /machine:i386 /def:..\lib\avcodec-53.def  /out:avcodec.lib
-lib /machine:i386 /def:..\lib\avdevice-53.def /out:avdevice.lib
-lib /machine:i386 /def:..\lib\avfilter-2.def  /out:avfilter.lib
-lib /machine:i386 /def:..\lib\avformat-53.def /out:avformat.lib
-lib /machine:i386 /def:..\lib\avutil-51.def   /out:avutil.lib
-lib /machine:i386 /def:..\lib\swscale-2.def   /out:swscale.lib
-@end example
-
-@end enumerate
-
-@anchor{Cross compilation for Windows with Linux}
-@subsection Cross compilation for Windows with Linux
-
-You must use the MinGW cross compilation tools available at
-@url{http://www.mingw.org/}.
-
-Then configure Libav with the following options:
-@example
-./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
-@end example
-(you can change the cross-prefix according to the prefix chosen for the
-MinGW tools).
-
-Then you can easily test Libav with @uref{http://www.winehq.com/, Wine}.
-
-@subsection 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:
-@example
-binutils, gcc4-core, make, git, mingw-runtime, texi2html
-@end example
-
-And the following "Utils" one:
-@example
-diffutils
-@end example
-
-Then run
-
-@example
-./configure
-@end example
-
-to make a static build.
-
-The current @code{gcc4-core} package is buggy and needs this flag to build
-shared libraries:
-
-@example
-./configure --enable-shared --disable-static --extra-cflags=-fno-reorder-functions
-@end example
-
-If you want to build Libav with additional libraries, download Cygwin
-"Devel" packages for Ogg and Vorbis from any Cygwin packages repository:
-@example
-libogg-devel, libvorbis-devel
-@end example
-
-These library packages are only available from
-@uref{http://sourceware.org/cygwinports/, Cygwin Ports}:
-
-@example
-yasm, libSDL-devel, libdirac-devel, libfaac-devel, libgsm-devel,
-libmp3lame-devel, libschroedinger1.0-devel, speex-devel, libtheora-devel,
-libxvidcore-devel
-@end example
-
-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 @code{libgetaddrinfo-devel} package, available at Cygwin Ports.
-
-@subsection 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:
-@example
-gcc-mingw-core, mingw-runtime, mingw-zlib
-@end example
-
-and add some special flags to your configure invocation.
-
-For a static build run
-@example
-./configure --target-os=mingw32 --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
-@end example
-
-and for a build with shared libraries
-@example
-./configure --target-os=mingw32 --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
-@end example
-
 @bye
diff --git a/doc/platform.texi b/doc/platform.texi
new file mode 100644
index 0000000000..6a44640e8f
--- /dev/null
+++ b/doc/platform.texi
@@ -0,0 +1,359 @@
+\input texinfo @c -*- texinfo -*-
+
+@settitle Platform Specific information
+@titlepage
+@center @titlefont{Platform Specific information}
+@end titlepage
+
+@top
+
+@contents
+
+@chapter Unix-like
+
+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:
+
+@example
+$(gcc -print-prog-name=as) --version
+@end example
+
+If not, then you should install a different compiler that has no
+hard-coded path to gas. In the worst case pass @code{--disable-asm}
+to configure.
+
+@section BSD
+
+BSD make will not build Libav, you need to install and use GNU Make
+(@file{gmake}).
+
+@section (Open)Solaris
+
+GNU Make is required to build Libav, so you have to invoke (@file{gmake}),
+standard Solaris Make will not work. When building with a non-c99 front-end
+(gcc, generic suncc) add either @code{--extra-libs=/usr/lib/values-xpg6.o}
+or @code{--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:
+
+@example
+bash ./configure
+@end example
+
+@anchor{Darwin}
+@section Darwin (OSX, iPhone)
+
+The toolchain provided with Xcode is sufficient to build the basic
+unacelerated code.
+
+OSX on PowerPC or ARM (iPhone) requires a preprocessor from
+@url{http://github.com/yuvi/gas-preprocessor} to build the optimized
+assembler functions. Just download the Perl script and put it somewhere
+in your PATH, Libav's configure will pick it up automatically.
+
+OSX on amd64 and x86 requires @command{yasm} to build most of the
+optimized assembler functions @url{http://mxcl.github.com/homebrew/, Homebrew},
+@url{http://www.gentoo.org/proj/en/gentoo-alt/prefix/bootstrap-macos.xml, Gentoo Prefix}
+or @url{http://www.macports.org, MacPorts} can easily provide it.
+
+
+@chapter DOS
+
+Using a cross-compiler is preferred for various reasons.
+@url{http://www.delorie.com/howto/djgpp/linux-x-djgpp.html}
+
+
+@chapter OS/2
+
+For information about compiling Libav on OS/2 see
+@url{http://www.edm2.com/index.php/FFmpeg}.
+
+
+@chapter Windows
+
+@section Native Windows compilation
+
+Libav can be built to run natively on Windows using the MinGW tools. Install
+the latest versions of MSYS and MinGW from @url{http://www.mingw.org/}.
+You can find detailed installation
+instructions in the download section and the FAQ.
+
+Libav 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:
+
+@itemize
+@item bash 3.1
+@item msys-make 3.81-2 (note: not mingw32-make)
+@item w32api 3.13
+@item mingw-runtime 3.15
+@end itemize
+
+Libav automatically passes @code{-fno-common} to the compiler to work around
+a GCC bug (see @url{http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37216}).
+
+Notes:
+
+@itemize
+
+@item Building natively using MSYS can be sped up by disabling implicit rules
+in the Makefile by calling @code{make -r} instead of plain @code{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
+@code{make install}).
+
+@item In order to compile AVplay, you must have the MinGW development library
+of @uref{http://www.libsdl.org/, SDL}.
+Edit the @file{bin/sdl-config} script so that it points to the correct prefix
+where SDL was installed. Verify that @file{sdl-config} can be launched from
+the MSYS command line.
+
+@item By using @code{./configure --enable-shared} when configuring Libav,
+you can build libavutil, libavcodec and libavformat as DLLs.
+
+@end itemize
+
+@section Microsoft Visual C++ compatibility
+
+As stated in the FAQ, Libav 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 @emph{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 Libav 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.
+
+@subsection Using static libraries
+
+Assuming you have just built and installed Libav in @file{/usr/local}.
+
+@enumerate
+
+@item 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.
+
+@item 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
+@file{libavformat/output-example.c} from the Libav distribution.
+
+@item 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 Libav includes were
+installed (i.e. @file{c:\msys\1.0\local\include}).
+Do not add MinGW's include directory here, or the include files will
+conflict with MSVC's.
+
+@item Still in the "Project / Properties" dialog box, select
+"Linker / General" from the tree view and edit the
+"Additional Library Directories" setting to contain the @file{lib}
+directory where Libav was installed (i.e. @file{c:\msys\1.0\local\lib}),
+the directory where MinGW libs are installed (i.e. @file{c:\mingw\lib}),
+and the directory where MinGW's GCC libs are installed
+(i.e. @file{C:\mingw\lib\gcc\mingw32\4.2.1-sjlj}). Then select
+"Linker / Input" from the tree view, and add the files @file{libavformat.a},
+@file{libavcodec.a}, @file{libavutil.a}, @file{libmingwex.a},
+@file{libgcc.a}, and any other libraries you used (i.e. @file{libz.a})
+to the end of "Additional Dependencies".
+
+@item 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".
+
+@item Click "OK" to close the "Project / Properties" dialog box.
+
+@item MSVC++ lacks some C99 header files that are fundamental for Libav.
+Get msinttypes from @url{http://code.google.com/p/msinttypes/downloads/list}
+and install it in MSVC++'s include directory
+(i.e. @file{C:\Program Files\Microsoft Visual Studio 8\VC\include}).
+
+@item MSVC++ also does not understand the @code{inline} keyword used by
+Libav, so you must add this line before @code{#include}ing libav*:
+@example
+#define inline _inline
+@end example
+
+@item Build your application, everything should work.
+
+@end enumerate
+
+@subsection Using shared libraries
+
+This is how to create DLL and LIB files that are compatible with MSVC++:
+
+Within the MSYS shell, build Libav with
+
+@example
+./configure --enable-shared
+make
+make install
+@end example
+
+Your install path (@file{/usr/local/} by default) should now have the
+necessary DLL and LIB files under the @file{bin} directory.
+
+Alternatively, build the libraries with a cross compiler, according to
+the instructions below in @ref{Cross compilation for Windows with Linux}.
+
+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. @file{c:\msys\usr\local\bin}). This is not a typo, the LIB files are
+installed in the @file{bin} directory. And instead of adding the static
+libraries (@file{libxxx.a} files) you should add the MSVC import libraries
+(@file{avcodec.lib}, @file{avformat.lib}, and
+@file{avutil.lib}). Note that you should not use the GCC import
+libraries (@file{libxxx.dll.a} files), as these will give you undefined
+reference errors. There should be no need for @file{libmingwex.a},
+@file{libgcc.a}, and @file{wsock32.lib}, nor any other external library
+statically linked into the DLLs.
+
+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:
+@example
+extern __declspec(dllimport) const AVPixFmtDescriptor av_pix_fmt_descriptors[];
+@end example
+
+Note that using import libraries created by dlltool requires
+the linker optimization option to be set to
+"References: Keep Unreferenced Data (@code{/OPT:NOREF})", otherwise
+the resulting binaries will fail during runtime. This isn't
+required when using import libraries generated by lib.exe.
+This issue is reported upstream at
+@url{http://sourceware.org/bugzilla/show_bug.cgi?id=12633}.
+
+To create import libraries that work with the @code{/OPT:REF} option
+(which is enabled by default in Release mode), follow these steps:
+
+@enumerate
+
+@item Open @file{Visual Studio 2005 Command Prompt}.
+
+Alternatively, in a normal command line prompt, call @file{vcvars32.bat}
+which sets up the environment variables for the Visual C++ tools
+(the standard location for this file is
+@file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat}).
+
+@item Enter the @file{bin} directory where the created LIB and DLL files
+are stored.
+
+@item Generate new import libraries with @file{lib.exe}:
+
+@example
+lib /machine:i386 /def:..\lib\avcodec-53.def  /out:avcodec.lib
+lib /machine:i386 /def:..\lib\avdevice-53.def /out:avdevice.lib
+lib /machine:i386 /def:..\lib\avfilter-2.def  /out:avfilter.lib
+lib /machine:i386 /def:..\lib\avformat-53.def /out:avformat.lib
+lib /machine:i386 /def:..\lib\avutil-51.def   /out:avutil.lib
+lib /machine:i386 /def:..\lib\swscale-2.def   /out:swscale.lib
+@end example
+
+@end enumerate
+
+@anchor{Cross compilation for Windows with Linux}
+@section Cross compilation for Windows with Linux
+
+You must use the MinGW cross compilation tools available at
+@url{http://www.mingw.org/}.
+
+Then configure Libav with the following options:
+@example
+./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
+@end example
+(you can change the cross-prefix according to the prefix chosen for the
+MinGW tools).
+
+Then you can easily test Libav with @uref{http://www.winehq.com/, Wine}.
+
+@section 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:
+@example
+binutils, gcc4-core, make, git, mingw-runtime, texi2html
+@end example
+
+And the following "Utils" one:
+@example
+diffutils
+@end example
+
+Then run
+
+@example
+./configure
+@end example
+
+to make a static build.
+
+The current @code{gcc4-core} package is buggy and needs this flag to build
+shared libraries:
+
+@example
+./configure --enable-shared --disable-static --extra-cflags=-fno-reorder-functions
+@end example
+
+If you want to build Libav with additional libraries, download Cygwin
+"Devel" packages for Ogg and Vorbis from any Cygwin packages repository:
+@example
+libogg-devel, libvorbis-devel
+@end example
+
+These library packages are only available from
+@uref{http://sourceware.org/cygwinports/, Cygwin Ports}:
+
+@example
+yasm, libSDL-devel, libdirac-devel, libfaac-devel, libgsm-devel,
+libmp3lame-devel, libschroedinger1.0-devel, speex-devel, libtheora-devel,
+libxvidcore-devel
+@end example
+
+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 @code{libgetaddrinfo-devel} package, available at Cygwin Ports.
+
+@section 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:
+@example
+gcc-mingw-core, mingw-runtime, mingw-zlib
+@end example
+
+and add some special flags to your configure invocation.
+
+For a static build run
+@example
+./configure --target-os=mingw32 --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
+@end example
+
+and for a build with shared libraries
+@example
+./configure --target-os=mingw32 --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
+@end example
+
+@bye