在VC2015中调试FFMPEG

编译X264需要至少 VS2013 update 2 以上版本. 本文使用 VS2015.

示例工程：https://github.com/gitgjogh/FFmpeg-gitgjogh/tree/msvc/build_msvc

Build Libav*** Using MSVC Compiler Under MINGW32

Import vcvar Into MSYS (MINGW32)

• Scheme#1: From Start Menu->vs2015->tools->VS2015 x86 本机工具命令提示 start msys.bat binding with mingw32. (Don't use mingw64)
• Scheme#2: Add call "C:/Program Files/Microsoft Visual Studio 14.0/VC/vcvarsall.bat" to the 1st line of msys.bat. Then kick off msys.bat.

Confirm vcvar has been imported:

$ which link nmake  
/c/Program Files (x86)/Microsoft Visual Studio 14.0/VC/BIN/link.exe  
/c/Program Files (x86)/Microsoft Visual Studio 14.0/VC/BIN/nmake.exe  

nmake is the make programe under MSVC. Needed for making zlib. See later.

Fix Collision Between VC-link And MSYS-LINK

• VC-link links obj/libs files to create exe/dll file
• MSYS-LINK creates a link named FILE2 to an existing FILE1.

It is possible that msys's file linker or coreutils's linker conflicts with MSVC’s linker. You can find out by runningwhich link to see which link binary you are using. If it is located at /bin/link.exe, mv /bin/link.exe to /bin/msys-link.exe

Yasm

X264

You need at least VS2013 update 2 to compile x264.

Go to an x264 source tree

> $ CC=cl ./configure --prefix=${PATH_TO_build_msvc} --enable-static --disable-gpl --enable-debug --enable-win32thread
> $ make && make install  
> $ MSVC='/c/Program Files (x86)/Microsoft Visual Studio 14.0/VC/'  
> $ cp libx264.lib ${MSVC}/lib/x264.lib
> $ cp x264.h x264_config.h ${MSVC}/include/

Zlib

• $ cd zlib-1.2.8
• Edit win32/Makefile.msc so that CFLAGS uses -MT instead of -MD, since this is how FFmpeg is built as well.
  > del CFLAGS = -nologo -MD -W3 -O2 -Oy--Zi -Fd"zlib" $(LOC)
  > add CFLAGS = -nologo -MT -W3 -O2 -Oy -Zi -Fd"zlib" $(LOC)
• Edit zconf.h and remove its inclusion of unistd.h. This gets erroneously included when building FFmpeg.
• $ nmake -f win32/Makefile.msc
• Move zlib.lib, zconf.h and zlib.h to somewhere MSVC can see.
  > $ MSVC='/c/Program Files (x86)/Microsoft Visual Studio 14.0/VC/'
  > $ cp zlib.lib ${MSVC}/VC/lib/
  > $ cp zconf.h zlib.h ${MSVC}/include/

reference: http://www.ffmpeg.org/platform.html

Build FFmpeg Libs Using msvc Toolchain

under build_msvc:

> $ madir build && cd build  
> $ ../../configure --prefix=`pwd`/.. --toolchain=msvc --disable-shared --enable-static --enable-libx264 --enable-gpl  
> $ make --debug | tee make.log  
> $ make install  

If configuration failed because 'can't find libx264':

> $ export PKG_CONFIG_PATH=${PATH_TO_build_msvc}/lib/pkg-config:$PKG_CONFIG_PATH 

Create Win32 Console App. Project

Add the following files to the project:

cmdutils.h cmdutils_common_opt.h build/config.h ffmpeg.h  
cmdutils.c ffmpeg.c ffmpeg_dxva2.cffmpeg_filter.c ffmpeg_opt.c  

Clue: Run grep "^CC" make.log to see what files are compiled.

Add Dependency

• Additional Include Directories: include;build
• Additional Library Directories: lib
• Additional Dependent Libraries:vfw32.lib;psapi.lib;strmiids.lib;shlwapi.lib;ws2_32.lib;x264.lib;zlib.lib;libavdevice.a;libavfilter.a;libswscale.a;libpostproc.a;libavformat.a;libavcodec.a;libswresample.a;libavutil.a

Clue#1: Under build_msvc, run env PKG_CONFIG_PATH=lib/pkgconfig/ pkg-config --libs libavdevice to see what additional libs need to be added. For example, my result is:

vfw32.lib user32.lib gdi32.lib psapi.lib ole32.lib strmiids.lib uuid.lib oleaut32.lib shlwapi.lib ws2_32.lib x264.lib zlib.lib advapi32.lib shell32.lib -L../lib -lavdevice -lavfilter -lswscale -lpostproc -lavformat -lavcodec -libpath:../lib -lswresample -lavutil

Clue#2: The following lines in the generated 'Malefile' also can be took as reference to decide lib orders

# $(FFLIBS-yes) needs to be in linking order
FFLIBS-$(CONFIG_AVDEVICE)   += avdevice
FFLIBS-$(CONFIG_AVFILTER)   += avfilter
FFLIBS-$(CONFIG_AVFORMAT)   += avformat
FFLIBS-$(CONFIG_AVCODEC)    += avcodec
FFLIBS-$(CONFIG_AVRESAMPLE) += avresample
FFLIBS-$(CONFIG_POSTPROC)   += postproc
FFLIBS-$(CONFIG_SWRESAMPLE) += swresample
FFLIBS-$(CONFIG_SWSCALE)    += swscale

Set Preprocessor

-D_ISOC99_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_WIN32_WINNT=0x0502 -nologo -D_USE_MATH_DEFINES -D_CRT_SECURE_NO_WARNINGS 

Clue#1: search 'CPPFLAGS','CFLAGS','CXXFLAGS'.'ASFLAGS' in 'config.mak' to see how autoconfig deal with 'inline','snprintf' compatibility by setting '--toolchain=msvc' option.

Clue#2: search '^cl' in 'config.log', see that how MSVC compiler 'cl.exe' is called. Here is an example:

"cl -D_ISOC99_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_WIN32_WINNT=0x0502 -nologo -D_USE_MATH_DEFINES -D_CRT_SECURE_NO_WARNINGS -I../include -Z7 -W4 -wd4244 -wd4127 -wd4018 -wd4389 -wd4146 -wd4057 -wd4204 -wd4706 -wd4305 -wd4152 -wd4324 -we4013 -wd4100 -wd4214 -wd4307 -wd4273 -wd4554 -wd4701 -O2 -Oy- -P -Fi./ffconf.wAKKajHY.o ./ffconf.FbkkcFDo.c"

Problems

Fix Collision Between LIBCMT.lib and msvcrtd.lib

1>------ 已启动生成:  项目: build_msvc, 配置: Debug Win32 ------  
1>LIBCMT.lib(open.obj) : error LNK2005: __sopen 已经在 MSVCRT.lib(MSVCR120.dll) 中定义  
1>LIBCMT.lib(invarg.obj) : error LNK2005: __invoke_watson 已经在 MSVCRT.lib(MSVCR120.dll) 中定义  
1>LIBCMT.lib(_file.obj) : error LNK2005: ___iob_func 已经在 MSVCRT.lib(MSVCR120.dll) 中定义  

reason: some code link to the static RTL(run time library), while some code link to dynamic RTL solution: set msvcr to /MT in "properties->C/C++->Code generation"

reference: https://msdn.microsoft.com/en-us/library/2kzt1wy3%28v=VS.71%29.aspx

Undefined Reference To 'avresample_version', 'postproc_version'

two scheme:

1) goto "cmdutil.c"::"print_all_libs_info()", comment the following two lines:
    // PRINT_LIB_INFO(avresample, AVRESAMPLE, flags, level);
    // PRINT_LIB_INFO(postproc, POSTPROC, flags, level);
2) configure --enable-avresample

Network Module

which has to link to the WINDOWS SDK, so be careful with how '_WIN32_WINNT' defined in 'config.mak' or 'config.log', copied it to the VC preprocessors. Reference to the "set preprocessor" section.