Commit be0efc0c authored by Martin Boehme's avatar Martin Boehme Committed by Diego Biurrun

Since there have been quite a few questions recently on how to use the

FFmpeg libraries with Visual C++, here's a patch for the documentation
that explains everything in (excruciating) detail.

patch by Martin Boehme <boehme -- at -- inb -- dot -- uni-luebeck -- dot -- de>

Originally committed as revision 4620 to svn://svn.ffmpeg.org/ffmpeg/trunk
parent 51587548
......@@ -160,8 +160,8 @@ related to the compiler.
Yes, but the MinGW tools @emph{must} be used to compile FFmpeg. You
can link the resulting DLLs with any other Windows program. Read the
@emph{Native Windows Compilation} section in the FFmpeg documentation
to find more information.
@emph{Native Windows Compilation} and @emph{Visual C++ compatibility}
sections in the FFmpeg documentation to find more information.
@section Can you add automake, libtool or autoconf support ?
......@@ -201,6 +201,7 @@ the compilation failure then you are probably not qualified for this.
You need a C compiler (Visual C++ is not compliant to the C standard).
If you wish - for whatever weird reason - to use Visual C++ for your
project then you can link the Visual C++ code with libav* as long as
you compile the latter with a working C compiler.
you compile the latter with a working C compiler. For more information, see
the @emph{Visual C++ compatibility} section in the FFmpeg documentation.
@bye
......@@ -918,10 +918,134 @@ headers in @file{Program Files/FFmpeg}.
when configuring FFmpeg, FFmpeg tries to use the Microsoft Visual
C++ @code{lib} tool to build @code{avcodec.lib} and
@code{avformat.lib}. With these libraries you can link your Visual C++
code directly with the FFmpeg DLLs.
code directly with the FFmpeg DLLs (see below).
@end itemize
@subsection Visual C++ compatibility
FFmpeg will not compile under Visual C++ -- and it has too many
dependencies on the GCC compiler to make a port viable. However,
if you want to use the FFmpeg libraries in your own applications,
you can still compile those applications using Visual C++. An
important restriction to this is that you have to use the
dynamically linked versions of the FFmpeg libraries (i.e. the
DLLs), and you have to make sure that Visual-C++-compatible
import libraries are created during the FFmpeg build process.
This description of how to use the FFmpeg libraries with Visual C++ is
based on Visual C++ 2005 Express Edition Beta 2. If you have a different
version, you might have to modify the procedures slightly.
Here are the step-by-step instructions for building the FFmpeg libraries
so they can be used with Visual C++:
@enumerate
@item Install Visual C++ (if you haven't done so already).
@item Install MinGW and MSYS as described above.
@item Add a call to @file{vcvars32.bat} (which sets up the environment
variables for the Visual C++ tools) as the first line of
@file{msys.bat}. The standard location for @file{vcvars32.bat} is
@file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
and the standard location for @file{msys.bat} is
@file{C:\msys\1.0\msys.bat}. If this corresponds to your setup, add the
following line as the first line of @file{msys.bat}:
@code{call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"}
@item Start the MSYS shell (file @file{msys.bat}) and type @code{link.exe}.
If you get a help message with the command line options of @code{link.exe},
this means your environment variables are set up correctly, the
Microsoft linker is on the path and will be used by FFmpeg to
create Visual-C++-compatible import libraries.
@item Extract the current version of FFmpeg (the latest release version or
the current CVS snapshot, whichever is recommended) and change to the
FFmpeg directory.
@item Type the command
@code{./configure --enable-shared --enable-memalign-hack} to configure and,
if that didn't produce any errors, type @code{make} to build FFmpeg.
@item The subdirectories @file{libavformat}, @file{libavcodec}, and
@file{libavutil} should now contain the files @file{avformat.dll},
@file{avformat.lib}, @file{avcodec.dll}, @file{avcodec.lib},
@file{avutil.dll}, and @file{avutil.lib}, respectively. Copy the three
DLLs to your System32 directory (typically @file{C:\Windows\System32}).
@end enumerate
And here is how to use these libraries with Visual C++:
@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 Visual C++ has already created for you. (Note that your source
filehas to have a @code{.cpp} extension; otherwise, Visual C++ won't
compile the FFmpeg headers correctly because in C mode, it doesn't
recognize the @code{inline} keyword.) For example, you can copy
@file{output_example.c} from the FFmpeg distribution (but you will
have to make minor modifications so the code will compile under
C++, see below).
@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 complete paths to the
@file{libavformat}, @file{libavcodec}, and @file{libavutil}
subdirectories of your FFmpeg directory. Note that the directories have
to be separated using semicolons. Now select "Linker / General" from the
tree view and edit the "Additional Library Directories" setting to
contain the same three directories.
@item Still in the "Project / Properties" dialog box, select "Linker / Input"
from the tree view, then add the files @file{avformat.lib},
@file{avcodec.lib}, and @file{avutil.lib} to the end of the "Additional
Dependencies". Note that the names of the libraries have to be separated
using spaces.
@item Now, select "C/C++ / Preprocessor" from the tree view. Select "Debug"
in the "Configuration" combo box. Add @code{EMULATE_INTTYPES} to the
"Preprocessor Definitions". (Note that the various preprocessor
definitions have to be separated using semicolons.) Select "Release" in
the "Configuration" combo box and, again, add @code{EMULATE_INTTYPES} to
the "Preprocessor Definitions". (This has to be done separately because
debug and release builds have different preprocessor definitions.)
Finally, 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 and build
the application. Hopefully, it should compile and run cleanly. If you
used @file{output_example.c} as your sample application, you will get a
few compiler errors, but they are easy to fix. The first type of error
occurs because Visual C++ doesn't allow an @code{int} to be converted to
an @code{enum} without a cast. To solve the problem, insert the required
casts (this error occurs once for a @code{CodecID} and once for a
@code{CodecType}). The second type of error occurs because C++ requires
the return value of @code{malloc} to be cast to the exact type of the
pointer it is being assigned to. Visual C++ will complain that, for
example, @code{(void *)} is being assigned to @code{(uint8_t *)} without
an explicit cast. So insert an explicit cast in these places to silence
the compiler. The third type of error occurs because the @code{snprintf}
library function is called @code{_snprintf} under Visual C++. So just
add an underscore to fix the problem. With these changes,
@file{output_example.c} should compile under Visual C++, and the
resulting executable should produce valid video files.
@end enumerate
@subsection Cross compilation for Windows with Linux
You must use the MinGW cross compilation tools available at
......
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