FFmpeg源代码简单分析：makefile
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FFmpeg的库函数源代码分析文章列表：
【架构图】
FFmpeg源代码结构图 - 解码
FFmpeg源代码结构图 - 编码
【通用】
FFmpeg 源代码简单分析：av_register_all()
FFmpeg 源代码简单分析：avcodec_register_all()
FFmpeg 源代码简单分析：内存的分配和释放（av_malloc()、av_free()等）
FFmpeg 源代码简单分析：常见结构体的初始化和销毁（AVFormatContext，AVFrame等）
FFmpeg 源代码简单分析：avio_open2()
FFmpeg 源代码简单分析：av_find_decoder()和av_find_encoder()
FFmpeg 源代码简单分析：avcodec_open2()
FFmpeg 源代码简单分析：avcodec_close()
【解码】
图解FFMPEG打开媒体的函数avformat_open_input
FFmpeg 源代码简单分析：avformat_open_input()
FFmpeg 源代码简单分析：avformat_find_stream_info()
FFmpeg 源代码简单分析：av_read_frame()
FFmpeg 源代码简单分析：avcodec_decode_video2()
FFmpeg 源代码简单分析：avformat_close_input()
【编码】
FFmpeg 源代码简单分析：avformat_alloc_output_context2()
FFmpeg 源代码简单分析：avformat_write_header()
FFmpeg 源代码简单分析：avcodec_encode_video()
FFmpeg 源代码简单分析：av_write_frame()
FFmpeg 源代码简单分析：av_write_trailer()
【其它】
FFmpeg源代码简单分析：日志输出系统（av_log()等）
FFmpeg源代码简单分析：结构体成员管理系统-AVClass
FFmpeg源代码简单分析：结构体成员管理系统-AVOption
FFmpeg源代码简单分析：libswscale的sws_getContext()
FFmpeg源代码简单分析：libswscale的sws_scale()
FFmpeg源代码简单分析：libavdevice的avdevice_register_all()
FFmpeg源代码简单分析：libavdevice的gdigrab
【脚本】
FFmpeg源代码简单分析：makefile
FFmpeg源代码简单分析：configure
【H.264】
FFmpeg的H.264解码器源代码简单分析：概述
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本文记录FFmpeg的Makefile的源代码。Makefile用于编译FFmpeg的源代码。通过分析Makefile文件，可以了解FFmpeg的源代码生成的流程。有关Makefile这部分我本身基础不算很牢，很多地方还在慢慢摸索，所以分析的内容不能保证完全准确。以后有时间和其他朋友多交流再慢慢完善这篇文章。
PS：make有一个很有用的命令：“make -n”。该选项会显示命令，但不会执行命令，十分有助于分析Makefile
FFmpeg中与Makefile相关的文件
FFmpeg中与Makefile相关的文件主要有以下几个：根目录Makefile：最基本的Makefile；
config.mak：由configure生成的Makefile，保存了Configure的设置信息；
libavXXXX/Makefile：每个类库的Makefile（仅仅设置了几个变量）；
library.mak：编译类库的Makefile（和libavXXXX/Makefile配合使用）；
common.mak：包含一些通用代码的Makefile；
它们之间的关系如下图所示。
XXX.c：C语言文件；
XXX.h：C语言文件用到的头文件；
XXX.o：C语言文件对应的目标文件；
XXX.d：C语言文件对应的依赖关系文件；
Make Install 之间的关系
简单分析了一下Makefile中的make install之间的关系，如下图所示（使用的是MinGW编译器）。
从图中可以看出，install伪目标依赖于4个伪目标：
install-progs：安装应用程序ffmpeg.exe，ffplay.exe，ffprobe.exe；
install-data：安装数据（*.ffpreset之类的文件，没研究过）
install-libs：安装类库（libavcodec.dll等文件）
install-headers：安装头文件（libavcodec/avcodec.h等文件）
install-progs依赖于ffmpeg.exe，ffplay.exe，ffprobe.exe以及install-progs-yes伪目标。在CONFIG_SHARED取值为yes的情况下，install-progs-yes依赖于install-libs。
install-libs依赖于伪目标install-libs-yes。install-libs-yes的依赖关系位于library.mak文件中。如果CONFIG_STATIC取值为yes，install-libs-yes依赖于install-lib$(NAME)-static（其中${NAME}为类库文件名，例如avformat）；如果CONFIG_SHARED取值为yes，install-libs-yes依赖于install-lib$(NAME)-shared。install-headers依赖于伪目标install-lib$(NAME)-headers和install-lib$(NAME)-pkgconfig。
和install相对应，uninstall伪目标依赖于4个伪目标：uninstall-progs：卸载应用程序；
uninstall-data：卸载数据；
uninstall-libs：卸载类库；
uninstall-headers：卸载头文件；
其中uninstall-libs和uninstall-headers的依赖关系位于library.mak中。
根目录Makefile
根目录Makefile是最重要的。简单注释过的Makefile如下所示。
# FFmpeg Main Makefile # # 注释：雷霄骅 # [email protected] # http://blog.csdn.net/leixiaohua1020 # # FFmpeg的 Main Makefile。最重要。 MAIN_MAKEFILE=1 #重要：包含了configure信息 include config.mak #config.mak中： #SRC_PATH=. #在SRC_PATH搜索各种类型的文件 vpath %.c $(SRC_PATH) vpath %.cpp $(SRC_PATH) vpath %.h $(SRC_PATH) vpath %.S $(SRC_PATH) vpath %.asm $(SRC_PATH) vpath %.v $(SRC_PATH) vpath %.texi $(SRC_PATH) vpath %/fate_config.sh.template $(SRC_PATH) #CONFIG_XXX取值为yes #PROGS-yes= ffmpeg ffplay ffprobe PROGS-$(CONFIG_FFMPEG) += ffmpeg PROGS-$(CONFIG_FFPLAY) += ffplay PROGS-$(CONFIG_FFPROBE) += ffprobe PROGS-$(CONFIG_FFSERVER) += ffserver #config.mak中： #EXESUF=.exe #PROGSSUF= #$(var:%.c=%.o)意思是把.c 为结尾的变量替换成.o。 #没有“.c”的时候，代表匹配所有 PROGS := $(PROGS-yes:%=%$(EXESUF)) INSTPROGS = $(PROGS-yes:%=%$(PROGSSUF)$(EXESUF)) OBJS = $(PROGS-yes:%=%.o) cmdutils.o TESTTOOLS = audiogen videogen rotozoom tiny_psnr base64 HOSTPROGS := $(TESTTOOLS:%=tests/%) TOOLS = qt-faststart trasher TOOLS-$(CONFIG_ZLIB) += cws2fws #PROGS= ffmpeg.exe ffplay.exe ffprobe.exe #INSTPROGS= ffmpeg.exe ffplay.exe ffprobe.exe #OBJS= ffmpeg.o ffplay.o ffprobe.o BASENAMES = ffmpeg ffplay ffprobe ffserver ALLPROGS = $(BASENAMES:%=%$(PROGSSUF)$(EXESUF)) ALLPROGS_G = $(BASENAMES:%=%$(PROGSSUF)_g$(EXESUF)) ALLMANPAGES = $(BASENAMES:%=%.1) #ALLPROGS= ffmpeg.exe ffplay.exe ffprobe.exe ffserver.exe #ALLPROGS_G= ffmpeg_g.exe ffplay_g.exe ffprobe_g.exe ffserver_g.exe #ALLMANPAGES=ffmpeg.1 ffplay.1 ffprobe.1 ffserver.1 FFLIBS-$(CONFIG_AVDEVICE) += avdevice FFLIBS-$(CONFIG_AVFILTER) += avfilter FFLIBS-$(CONFIG_AVFORMAT) += avformat FFLIBS-$(CONFIG_AVCODEC) += avcodec FFLIBS-$(CONFIG_POSTPROC) += postproc FFLIBS-$(CONFIG_SWRESAMPLE)+= swresample FFLIBS-$(CONFIG_SWSCALE) += swscale #FFLIBS-yes= avdevice avfilter avformat avcodec postproc swresample swscale #一定需要libavutil FFLIBS := avutil #让通配符在变量中展开，需要使用wildcard关键字 DATA_FILES := $(wildcard $(SRC_PATH)/presets/*.ffpreset) $(SRC_PATH)/doc/ffprobe.xsd SKIPHEADERS = cmdutils_common_opts.h #重要 include $(SRC_PATH)/common.mak #依赖的类库 FF_EXTRALIBS := $(FFEXTRALIBS) FF_DEP_LIBS := $(DEP_LIBS) #伪目标 #all是最关键的，生成最后的程序 #all: ffmpeg.exe ffplay.exe ffprobe.exe # all: $(PROGS) #config.mak中： #EXESUF=.exe #PROGSSUF= #$@是一个自动化变量。可以简单理解为目标的集合。 #$<是一个自动化变量。可以简单理解为依赖目标的集合。 #%是通配符 #两个冒号，“静态模式规则”。 #ffmpeg_g.exe生成ffmpeg.exe；ffplay_g.exe生成ffplay.exe；ffprobe_g.exe生成ffprobe.exe #strip经常用来去除目标文件中的一些符号表、调试符号表信息,以减小程序的大小 $(PROGS): %$(EXESUF): %$(PROGSSUF)_g$(EXESUF) $(CP) $< $@$(PROGSSUF) $(STRIP) $@$(PROGSSUF) $(TOOLS): %$(EXESUF): %.o $(LD) $(LDFLAGS) -o $@ $< $(ELIBS) tools/cws2fws$(EXESUF): ELIBS = -lz config.h: .config .config: $(wildcard $(FFLIBS:%=$(SRC_PATH)/lib%/all*.c)) @-tput bold 2>/dev/null @-printf '\nWARNING: $(?F) newer than config.h, rerun configure\n\n' @-tput sgr0 2>/dev/null #给子目录中的Makefile使用的变量 SUBDIR_VARS := OBJS FFLIBS CLEANFILES DIRS TESTPROGS EXAMPLES SKIPHEADERS \ ALTIVEC-OBJS MMX-OBJS NEON-OBJS X86-OBJS YASM-OBJS-FFT YASM-OBJS \ HOSTPROGS BUILT_HEADERS TESTOBJS ARCH_HEADERS ARMV6-OBJS TOOLS define RESET $(1) := $(1)-yes := endef #$(call <expression>,<parm1>,<parm2>,<parm3>...) #当make执行这个函数时，<expression>参数中的变量，如$(1)，$(2)，$(3)等，会被参数 #<parm1>，<parm2>，<parm3>依次取代。而<expression>的返回值就是call函数的返回值。 #命令包=========================== #用于编译每个库 #$(1)取值为libavcodec，libavcodec等等 define DOSUBDIR $(foreach V,$(SUBDIR_VARS),$(eval $(call RESET,$(V)))) SUBDIR := $(1)/ #每个库目录下的Makefile include $(SRC_PATH)/$(1)/Makefile #注：make一般情况下如果在中途检测到有执行出错的情况(返回非 0 状态)，那么就会放弃对当前规则后续命令的执行。 #在命令前面加上“-”号之后，就算执行错误了，也会继续执行下去 -include $(SRC_PATH)/$(1)/$(ARCH)/Makefile #编译类库 include $(SRC_PATH)/library.mak endef #================================= #$(foreach <var>,<list>,<text>) #把参数<list>中的单词逐一取出放到参数<var>所指定的变量中， #然后再执行<text>所包含的表达式。 #$(eval text) #text的内容将作为makefile的一部分而被make解析和执行 # #循环调用DOSUBDIR命令包 #这一步会将libavcodec，libavformat等文件夹下的Makefile包含进来。 $(foreach D,$(FFLIBS),$(eval $(call DOSUBDIR,lib$(D)))) #ffplay需要SDL ffplay.o: CFLAGS += $(SDL_CFLAGS) ffplay_g$(EXESUF): FF_EXTRALIBS += $(SDL_LIBS) ffserver_g$(EXESUF): LDFLAGS += $(FFSERVERLDFLAGS) #链接生成ffmpeg_g.exe等等 #FF_DEP_LIBS= libavcodec/libavcodec.a libavutil/libavutil.a .... %$(PROGSSUF)_g$(EXESUF): %.o cmdutils.o $(FF_DEP_LIBS) $(LD) $(LDFLAGS) -o $@ $< cmdutils.o $(FF_EXTRALIBS) OBJDIRS += tools -include $(wildcard tools/*.d) VERSION_SH = $(SRC_PATH)/version.sh GIT_LOG = $(SRC_PATH)/.git/logs/HEAD .version: $(wildcard $(GIT_LOG)) $(VERSION_SH) config.mak .version: M=@ version.h .version: $(M)$(VERSION_SH) $(SRC_PATH) version.h $(EXTRA_VERSION) $(Q)touch .version # force version.sh to run whenever version might have changed -include .version #安装install #安装程序 ifdef PROGS install: install-progs install-data endif #安装类库和头文件 install: install-libs install-headers #install-libs-yes位于library.mak install-libs: install-libs-yes install-progs-yes: install-progs-$(CONFIG_SHARED): install-libs #config.mak中： #BINDIR=$(DESTDIR)${prefix}/bin #INSTALL=install #cp与install区别： #cp会先清空文件后往里写入新文件，而install则会先删除掉原先的文件然后写入新文件。 install-progs: install-progs-yes $(PROGS) $(Q)mkdir -p "$(BINDIR)" $(INSTALL) -c -m 755 $(INSTPROGS) "$(BINDIR)" install-data: $(DATA_FILES) $(Q)mkdir -p "$(DATADIR)" $(INSTALL) -m 644 $(DATA_FILES) "$(DATADIR)" #卸载 uninstall: uninstall-libs uninstall-headers uninstall-progs uninstall-data #addprefix()用于加前缀 #在这里获取ffmpeg.exe等的完整路径（用于删除） uninstall-progs: $(RM) $(addprefix "$(BINDIR)/", $(ALLPROGS)) uninstall-data: $(RM) -r "$(DATADIR)" #清空 clean:: $(RM) $(ALLPROGS) $(ALLPROGS_G) $(RM) $(CLEANSUFFIXES) $(RM) $(TOOLS) $(RM) $(CLEANSUFFIXES:%=tools/%) $(RM) coverage.info $(RM) -r coverage-html distclean:: $(RM) $(DISTCLEANSUFFIXES) $(RM) config.* .version version.h libavutil/avconfig.h config: $(SRC_PATH)/configure $(value FFMPEG_CONFIGURATION) # Without the sed genthml thinks "libavutil" and "./libavutil" are two different things coverage.info: $(wildcard *.gcda *.gcno */*.gcda */*.gcno */*/*.gcda */*/*.gcno) $(Q)lcov -c -d . -b . | sed -e 's#/./#/#g' > $@ coverage-html: coverage.info $(Q)mkdir -p $@ $(Q)genhtml -o $@ $< $(Q)touch $@ include $(SRC_PATH)/doc/Makefile include $(SRC_PATH)/tests/Makefile $(sort $(OBJDIRS)): $(Q)mkdir -p $@ # Dummy rule to stop make trying to rebuild removed or renamed headers %.h: @: # Disable suffix rules. Most of the builtin rules are suffix rules, # so this saves some time on slow systems. .SUFFIXES: #显示地指明一个目标是“伪目标” .PHONY: all all-yes alltools *clean config examples install* .PHONY: testprogs uninstall*
根目录Makefile代码一开始的时候包含了config.mak文件。这个文件是运行./configure的后生成的配置文件，包含了所有的配置信息。
随后代码定义了ffplay.exe，ffmpeg.exe，ffprobe.exe与ffplay_g.exe，ffmpeg_g.exe，ffprobe_g.exe的依赖关系。然后定义了ffplay_g.exe，ffmpeg_g.exe，ffprobe_g.exe与libavformat，libavcodec等这些类库的依赖关系。
根目录Makefile中也定义了all，install，uninstall，clean等等一系列的伪目标，这样可以通过给Makefile指定不同的目标来完成不同的事。
此外根目录的Makefile中有一个很重要的命令包DOSUBDIR。在该命令包通过包含libavXXX/Makefile和library.mak等文件，定义了FFmpeg类库（例如libavformat，libavcodec，libavutil等）的依赖关系。config.mak
config.mak文件是运行./configure的后生成的配置文件，包含了所有的配置信息。简单注释过的config.mak的代码如下所示。# FFmpeg config.mak # # 注释：雷霄骅 # [email protected] # http://blog.csdn.net/leixiaohua1020 # # Configure脚本生成的Makefile，包含了各种配置信息。 # # Automatically generated by configure - do not modify! #基本信息 ifndef FFMPEG_CONFIG_MAK FFMPEG_CONFIG_MAK=1 FFMPEG_CONFIGURATION= #各种路径======================================== prefix=/usr/local LIBDIR=$(DESTDIR)${prefix}/lib SHLIBDIR=$(DESTDIR)${prefix}/bin INCDIR=$(DESTDIR)${prefix}/include BINDIR=$(DESTDIR)${prefix}/bin DATADIR=$(DESTDIR)${prefix}/share/ffmpeg MANDIR=$(DESTDIR)${prefix}/share/man #是个相对路径 SRC_PATH=. ifndef MAIN_MAKEFILE SRC_PATH:=$(SRC_PATH:.%=..%) endif #工具集========================================== CC_IDENT=gcc 4.6.2 (GCC) #架构 ARCH=x86 #编译器 CC=gcc CXX=g++ AS=gcc #链接器 LD=gcc DEPCC=gcc #汇编器 YASM=yasm YASMDEP=yasm #生成静态库.a工具 AR=ar RANLIB=ranlib CP=cp -p LN_S=ln -sf STRIP=strip #参数集========================================== #编译器的参数 CPPFLAGS= -D_ISOC99_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -U__STRICT_ANSI__ CFLAGS= -std=c99 -fno-common -fomit-frame-pointer -I/include/SDL -D_GNU_SOURCE=1 -Dmain=SDL_main -g -Wdeclaration-after-statement -Wall -Wno-parentheses -Wno-switch -Wno-format-zero-length -Wdisabled-optimization -Wpointer-arith -Wredundant-decls -Wno-pointer-sign -Wcast-qual -Wwrite-strings -Wtype-limits -Wundef -Wmissing-prototypes -Wno-pointer-to-int-cast -Wstrict-prototypes -O3 -fno-math-errno -fno-signed-zeros -fno-tree-vectorize -Werror=implicit-function-declaration -Werror=missing-prototypes CXXFLAGS= -D__STDC_CONSTANT_MACROS ASFLAGS= -g #目标文件有关的参数 AS_O=-o $@ CC_O=-o $@ CXX_O=-o $@ #链接器有关的参数 LDFLAGS= -Wl,--as-needed -Wl,--warn-common -Wl,-rpath-link=libpostproc:libswresample:libswscale:libavfilter:libavdevice:libavformat:libavcodec:libavutil FFSERVERLDFLAGS=-Wl,-E SHFLAGS=-shared -Wl,--output-def,$$(@:$(SLIBSUF)=.def) -Wl,--out-implib,$(SUBDIR)lib$(SLIBNAME:$(SLIBSUF)=.dll.a) -Wl,--enable-runtime-pseudo-reloc -Wl,--enable-auto-image-base -Wl,-Bsymbolic -Wl,--version-script,$(SUBDIR)lib$(NAME).ver YASMFLAGS=-f win32 -DPREFIX #前缀后缀======================================== BUILDSUF= PROGSSUF= #${NAME}位于每个liavXXX/Makefile中，例如avformat FULLNAME=$(NAME)$(BUILDSUF) LIBPREF=lib LIBSUF=.a #例如libavformat.a LIBNAME=$(LIBPREF)$(FULLNAME)$(LIBSUF) SLIBPREF= SLIBSUF=.dll EXESUF=.exe EXTRA_VERSION= DEPFLAGS=$(CPPFLAGS) $(CFLAGS) -MM CCDEP= CXXDEP=$(DEPCC) $(DEPFLAGS) $< | sed -e "/^\#.*/d" -e "s,^[[:space:]]*$(*F)\\.o,$(@D)/$(*F).o," > $(@:.o=.d) ASDEP= CC_DEPFLAGS=-MMD -MF $(@:.o=.d) -MT $@ AS_DEPFLAGS=-MMD -MF $(@:.o=.d) -MT $@ HOSTCC=gcc HOSTCFLAGS=-D_ISOC99_SOURCE -O3 -g -std=c99 -Wall HOSTEXESUF=.exe HOSTLDFLAGS= HOSTLIBS=-lm TARGET_EXEC= TARGET_PATH=$(CURDIR) #SDL SDL_LIBS=-L/lib -lmingw32 -lSDLmain -lSDL -mwindows SDL_CFLAGS=-I/include/SDL -D_GNU_SOURCE=1 -Dmain=SDL_main LIB_INSTALL_EXTRA_CMD=$$(RANLIB) "$(LIBDIR)/$(LIBNAME)" #链接 EXTRALIBS=-lavicap32 -lws2_32 -L/lib -lmingw32 -lSDLmain -lSDL -mwindows -lm -lz -lpsapi INSTALL=install LIBTARGET=i386 #例如libavformat.dll SLIBNAME=$(SLIBPREF)$(FULLNAME)$(SLIBSUF) #LIBVERSION变量位于library.mak #例如libavformat-53.dll #生成的Dll似乎就是这个版本的 SLIBNAME_WITH_VERSION=$(SLIBPREF)$(FULLNAME)-$(LIBVERSION)$(SLIBSUF) #例如libavformat-53.31.100.dll SLIBNAME_WITH_MAJOR=$(SLIBPREF)$(FULLNAME)-$(LIBMAJOR)$(SLIBSUF) SLIB_CREATE_DEF_CMD= #生成导出库lib，会调用lib.exe SLIB_EXTRA_CMD=-lib.exe /machine:$(LIBTARGET) /def:$$(@:$(SLIBSUF)=.def) /out:$(SUBDIR)$(SLIBNAME:$(SLIBSUF)=.lib) SLIB_INSTALL_NAME=$(SLIBNAME_WITH_MAJOR) SLIB_INSTALL_LINKS= SLIB_INSTALL_EXTRA_LIB=lib$(SLIBNAME:$(SLIBSUF)=.dll.a) $(SLIBNAME_WITH_MAJOR:$(SLIBSUF)=.def) SLIB_INSTALL_EXTRA_SHLIB=$(SLIBNAME:$(SLIBSUF)=.lib) SAMPLES:=$(FATE_SAMPLES) NOREDZONE_FLAGS=-mno-red-zone #版本信息======================================== libavcodec_VERSION=53.60.100 libavcodec_VERSION_MAJOR=53 libavdevice_VERSION=53.4.100 libavdevice_VERSION_MAJOR=53 libavfilter_VERSION=2.60.100 libavfilter_VERSION_MAJOR=2 libavformat_VERSION=53.31.100 libavformat_VERSION_MAJOR=53 libavutil_VERSION=51.34.101 libavutil_VERSION_MAJOR=51 libpostproc_VERSION=52.0.100 libpostproc_VERSION_MAJOR=52 libswresample_VERSION=0.6.100 libswresample_VERSION_MAJOR=0 libswscale_VERSION=2.1.100 libswscale_VERSION_MAJOR=2 #组件配置======================================== #ARCH_ !ARCH_ALPHA=yes !ARCH_ARM=yes !ARCH_AVR32=yes !ARCH_AVR32_AP=yes !ARCH_AVR32_UC=yes !ARCH_BFIN=yes !ARCH_IA64=yes !ARCH_M68K=yes !ARCH_MIPS=yes !ARCH_MIPS64=yes !ARCH_PARISC=yes !ARCH_PPC=yes !ARCH_PPC64=yes !ARCH_S390=yes !ARCH_SH4=yes !ARCH_SPARC=yes !ARCH_SPARC64=yes !ARCH_TOMI=yes ARCH_X86=yes ARCH_X86_32=yes !ARCH_X86_64=yes #HAVE_ !HAVE_ALTIVEC=yes HAVE_AMD3DNOW=yes HAVE_AMD3DNOWEXT=yes !HAVE_ARMV5TE=yes !HAVE_ARMV6=yes !HAVE_ARMV6T2=yes !HAVE_ARMVFP=yes HAVE_AVX=yes !HAVE_IWMMXT=yes !HAVE_MMI=yes HAVE_MMX=yes HAVE_MMX2=yes !HAVE_NEON=yes !HAVE_PPC4XX=yes HAVE_SSE=yes HAVE_SSSE3=yes !HAVE_VFPV3=yes !HAVE_VIS=yes !HAVE_BIGENDIAN=yes HAVE_FAST_UNALIGNED=yes !HAVE_PTHREADS=yes HAVE_W32THREADS=yes !HAVE_OS2THREADS=yes HAVE_ALIGNED_STACK=yes !HAVE_ALSA_ASOUNDLIB_H=yes !HAVE_ALTIVEC_H=yes !HAVE_ARPA_INET_H=yes !HAVE_ASM_MOD_Y=yes !HAVE_ASM_TYPES_H=yes HAVE_ATTRIBUTE_MAY_ALIAS=yes HAVE_ATTRIBUTE_PACKED=yes HAVE_CBRTF=yes HAVE_CLOSESOCKET=yes !HAVE_CMOV=yes !HAVE_DCBZL=yes !HAVE_DEV_BKTR_IOCTL_BT848_H=yes !HAVE_DEV_BKTR_IOCTL_METEOR_H=yes !HAVE_DEV_IC_BT8XX_H=yes !HAVE_DEV_VIDEO_BKTR_IOCTL_BT848_H=yes !HAVE_DEV_VIDEO_METEOR_IOCTL_METEOR_H=yes !HAVE_DLFCN_H=yes !HAVE_DLOPEN=yes HAVE_DOS_PATHS=yes HAVE_EBP_AVAILABLE=yes HAVE_EBX_AVAILABLE=yes HAVE_EXP2=yes HAVE_EXP2F=yes !HAVE_FAST_64BIT=yes HAVE_FAST_CLZ=yes !HAVE_FAST_CMOV=yes !HAVE_FCNTL=yes !HAVE_FORK=yes !HAVE_GETADDRINFO=yes !HAVE_GETHRTIME=yes HAVE_GETPROCESSAFFINITYMASK=yes HAVE_GETPROCESSMEMORYINFO=yes HAVE_GETPROCESSTIMES=yes !HAVE_GETRUSAGE=yes HAVE_GNU_AS=yes !HAVE_IBM_ASM=yes !HAVE_INET_ATON=yes HAVE_INLINE_ASM=yes HAVE_ISATTY=yes HAVE_KBHIT=yes !HAVE_LDBRX=yes HAVE_LLRINT=yes HAVE_LLRINTF=yes HAVE_LOCAL_ALIGNED_16=yes HAVE_LOCAL_ALIGNED_8=yes !HAVE_LOCALTIME_R=yes HAVE_LOG2=yes HAVE_LOG2F=yes !HAVE_LOONGSON=yes HAVE_LRINT=yes HAVE_LRINTF=yes !HAVE_LZO1X_999_COMPRESS=yes !HAVE_MACHINE_IOCTL_BT848_H=yes !HAVE_MACHINE_IOCTL_METEOR_H=yes HAVE_MAKEINFO=yes HAVE_MALLOC_H=yes HAVE_MAPVIEWOFFILE=yes !HAVE_MEMALIGN=yes !HAVE_MKSTEMP=yes !HAVE_MMAP=yes HAVE_PEEKNAMEDPIPE=yes !HAVE_POLL_H=yes !HAVE_POSIX_MEMALIGN=yes HAVE_ROUND=yes HAVE_ROUNDF=yes !HAVE_SCHED_GETAFFINITY=yes HAVE_SDL=yes HAVE_SDL_VIDEO_SIZE=yes HAVE_SETMODE=yes !HAVE_SETRLIMIT=yes !HAVE_SNDIO_H=yes HAVE_SOCKLEN_T=yes !HAVE_SOUNDCARD_H=yes !HAVE_STRERROR_R=yes !HAVE_STRPTIME=yes HAVE_STRUCT_ADDRINFO=yes HAVE_STRUCT_IPV6_MREQ=yes !HAVE_STRUCT_RUSAGE_RU_MAXRSS=yes HAVE_STRUCT_SOCKADDR_IN6=yes !HAVE_STRUCT_SOCKADDR_SA_LEN=yes HAVE_STRUCT_SOCKADDR_STORAGE=yes !HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE=yes HAVE_SYMVER=yes HAVE_SYMVER_ASM_LABEL=yes !HAVE_SYMVER_GNU_ASM=yes !HAVE_SYSCONF=yes !HAVE_SYSCTL=yes !HAVE_SYS_MMAN_H=yes HAVE_SYS_PARAM_H=yes !HAVE_SYS_RESOURCE_H=yes !HAVE_SYS_SELECT_H=yes !HAVE_SYS_SOUNDCARD_H=yes !HAVE_SYS_VIDEOIO_H=yes !HAVE_TERMIOS_H=yes HAVE_THREADS=yes HAVE_TRUNC=yes HAVE_TRUNCF=yes !HAVE_VFP_ARGS=yes HAVE_VIRTUALALLOC=yes HAVE_WINSOCK2_H=yes !HAVE_XFORM_ASM=yes !HAVE_XMM_CLOBBERS=yes HAVE_YASM=yes #CONFIG_ CONFIG_BSFS=yes CONFIG_DECODERS=yes CONFIG_DEMUXERS=yes CONFIG_ENCODERS=yes CONFIG_FILTERS=yes !CONFIG_HWACCELS=yes CONFIG_INDEVS=yes CONFIG_MUXERS=yes CONFIG_OUTDEVS=yes CONFIG_PARSERS=yes CONFIG_PROTOCOLS=yes CONFIG_FFPLAY=yes CONFIG_FFPROBE=yes !CONFIG_FFSERVER=yes CONFIG_FFMPEG=yes !CONFIG_AVPLAY=yes !CONFIG_AVPROBE=yes !CONFIG_AVSERVER=yes CONFIG_AANDCT=yes CONFIG_AC3DSP=yes CONFIG_AVCODEC=yes CONFIG_AVDEVICE=yes CONFIG_AVFILTER=yes CONFIG_AVFORMAT=yes !CONFIG_AVISYNTH=yes !CONFIG_BZLIB=yes !CONFIG_CRYSTALHD=yes CONFIG_DCT=yes !CONFIG_DOC=yes CONFIG_DWT=yes !CONFIG_DXVA2=yes CONFIG_FASTDIV=yes CONFIG_FFT=yes !CONFIG_FREI0R=yes !CONFIG_GNUTLS=yes CONFIG_GOLOMB=yes !CONFIG_GPL=yes !CONFIG_GRAY=yes CONFIG_H264CHROMA=yes CONFIG_H264DSP=yes CONFIG_H264PRED=yes !CONFIG_HARDCODED_TABLES=yes CONFIG_HUFFMAN=yes !CONFIG_LIBAACPLUS=yes !CONFIG_LIBASS=yes !CONFIG_LIBCDIO=yes !CONFIG_LIBCELT=yes !CONFIG_LIBDC1394=yes !CONFIG_LIBDIRAC=yes !CONFIG_LIBFAAC=yes !CONFIG_LIBFREETYPE=yes !CONFIG_LIBGSM=yes !CONFIG_LIBMODPLUG=yes !CONFIG_LIBMP3LAME=yes !CONFIG_LIBNUT=yes !CONFIG_LIBOPENCORE_AMRNB=yes !CONFIG_LIBOPENCORE_AMRWB=yes !CONFIG_LIBOPENCV=yes !CONFIG_LIBOPENJPEG=yes !CONFIG_LIBPULSE=yes !CONFIG_LIBRTMP=yes !CONFIG_LIBSCHROEDINGER=yes !CONFIG_LIBSPEEX=yes !CONFIG_LIBSTAGEFRIGHT_H264=yes !CONFIG_LIBTHEORA=yes !CONFIG_LIBUTVIDEO=yes !CONFIG_LIBV4L2=yes !CONFIG_LIBVO_AACENC=yes !CONFIG_LIBVO_AMRWBENC=yes !CONFIG_LIBVORBIS=yes !CONFIG_LIBVPX=yes !CONFIG_LIBX264=yes !CONFIG_LIBXAVS=yes !CONFIG_LIBXVID=yes CONFIG_LPC=yes CONFIG_LSP=yes CONFIG_MDCT=yes CONFIG_MEMALIGN_HACK=yes !CONFIG_MLIB=yes CONFIG_MPEGAUDIODSP=yes CONFIG_NETWORK=yes !CONFIG_NONFREE=yes !CONFIG_OPENAL=yes !CONFIG_OPENSSL=yes !CONFIG_PIC=yes !CONFIG_POSTPROC=yes CONFIG_RDFT=yes CONFIG_RTPDEC=yes !CONFIG_RUNTIME_CPUDETECT=yes CONFIG_SAFE_BITSTREAM_READER=yes !CONFIG_SHARED=yes CONFIG_SINEWIN=yes !CONFIG_SMALL=yes !CONFIG_SRAM=yes CONFIG_STATIC=yes CONFIG_SWRESAMPLE=yes CONFIG_SWSCALE=yes CONFIG_SWSCALE_ALPHA=yes !CONFIG_THUMB=yes !CONFIG_VAAPI=yes !CONFIG_VDA=yes !CONFIG_VDPAU=yes !CONFIG_VERSION3=yes !CONFIG_X11GRAB=yes CONFIG_ZLIB=yes CONFIG_AVUTIL=yes !CONFIG_GPLV3=yes !CONFIG_LGPLV3=yes CONFIG_AAC_ADTSTOASC_BSF=yes CONFIG_CHOMP_BSF=yes CONFIG_DUMP_EXTRADATA_BSF=yes CONFIG_H264_MP4TOANNEXB_BSF=yes CONFIG_IMX_DUMP_HEADER_BSF=yes CONFIG_MJPEG2JPEG_BSF=yes CONFIG_MJPEGA_DUMP_HEADER_BSF=yes CONFIG_MP3_HEADER_COMPRESS_BSF=yes CONFIG_MP3_HEADER_DECOMPRESS_BSF=yes CONFIG_MOV2TEXTSUB_BSF=yes CONFIG_NOISE_BSF=yes CONFIG_REMOVE_EXTRADATA_BSF=yes CONFIG_TEXT2MOVSUB_BSF=yes CONFIG_AASC_DECODER=yes CONFIG_AMV_DECODER=yes CONFIG_ANM_DECODER=yes CONFIG_ANSI_DECODER=yes CONFIG_ASV1_DECODER=yes CONFIG_ASV2_DECODER=yes CONFIG_AURA_DECODER=yes CONFIG_AURA2_DECODER=yes CONFIG_AVRP_DECODER=yes CONFIG_AVS_DECODER=yes CONFIG_BETHSOFTVID_DECODER=yes CONFIG_BFI_DECODER=yes CONFIG_BINK_DECODER=yes CONFIG_BMP_DECODER=yes CONFIG_BMV_VIDEO_DECODER=yes CONFIG_C93_DECODER=yes CONFIG_CAVS_DECODER=yes CONFIG_CDGRAPHICS_DECODER=yes CONFIG_CINEPAK_DECODER=yes CONFIG_CLJR_DECODER=yes CONFIG_CSCD_DECODER=yes CONFIG_CYUV_DECODER=yes CONFIG_DFA_DECODER=yes CONFIG_DIRAC_DECODER=yes CONFIG_DNXHD_DECODER=yes CONFIG_DPX_DECODER=yes CONFIG_DSICINVIDEO_DECODER=yes CONFIG_DVVIDEO_DECODER=yes CONFIG_DXA_DECODER=yes CONFIG_DXTORY_DECODER=yes CONFIG_EACMV_DECODER=yes CONFIG_EAMAD_DECODER=yes CONFIG_EATGQ_DECODER=yes CONFIG_EATGV_DECODER=yes CONFIG_EATQI_DECODER=yes CONFIG_EIGHTBPS_DECODER=yes CONFIG_EIGHTSVX_EXP_DECODER=yes CONFIG_EIGHTSVX_FIB_DECODER=yes CONFIG_ESCAPE124_DECODER=yes CONFIG_ESCAPE130_DECODER=yes CONFIG_FFV1_DECODER=yes CONFIG_FFVHUFF_DECODER=yes CONFIG_FLASHSV_DECODER=yes CONFIG_FLASHSV2_DECODER=yes CONFIG_FLIC_DECODER=yes CONFIG_FLV_DECODER=yes CONFIG_FOURXM_DECODER=yes CONFIG_FRAPS_DECODER=yes CONFIG_FRWU_DECODER=yes CONFIG_GIF_DECODER=yes CONFIG_H261_DECODER=yes CONFIG_H263_DECODER=yes CONFIG_H263I_DECODER=yes CONFIG_H264_DECODER=yes #此处省略若干条… CONFIG_RTMP_PROTOCOL=yes CONFIG_RTMPT_PROTOCOL=yes CONFIG_RTMPE_PROTOCOL=yes CONFIG_RTMPTE_PROTOCOL=yes CONFIG_RTMPS_PROTOCOL=yes CONFIG_RTP_PROTOCOL=yes CONFIG_TCP_PROTOCOL=yes !CONFIG_TLS_PROTOCOL=yes CONFIG_UDP_PROTOCOL=yes #Test ACODEC_TESTS=ac3_fixed adpcm_adx adpcm_ima_qt adpcm_ima_wav adpcm_ms adpcm_swf adpcm_yam alac aref flac g722 g723_1 g726 mp2 pcm_alaw pcm_f32be pcm_f32le pcm_f64be pcm_f64le pcm_mulaw pcm_s16be pcm_s16le pcm_s24be pcm_s24daud pcm_s24le pcm_s32be pcm_s32le pcm_s8 pcm_u8 wmav1 wmav2 VCODEC_TESTS=amv asv1 asv2 cljr dnxhd_1080i dnxhd_720p dnxhd_720p_10bit dnxhd_720p_rd dv dv50 dv_411 error ffv1 flashsv flashsv2 flv h261 h263 h263p huffyuv jpeg2000 jpegls ljpeg mjpeg mpeg mpeg1b mpeg2 mpeg2_422 mpeg2_idct_int mpeg2_ilace mpeg2_ivlc_qprd mpeg2thread mpeg2thread_ilace mpeg4 mpeg4_adap mpeg4_qpel mpeg4_qprd mpeg4adv mpeg4nr mpeg4thread mpng msmpeg4 msmpeg4v2 msvideo1 prores qtrle qtrlegray rc rgb roq rv10 rv20 snow snowll svq1 v210 vref wmv1 wmv2 yuv zlib zmbv LAVF_TESTS=aiff alaw asf au avi bmp caf dpx dv_fmt ffm flv_fmt gif gxf jpg mkv mmf mov mpg mulaw mxf mxf_d10 nut ogg pbmpipe pcx pgm pgmpipe pixfmt png ppm ppmpipe rm rso sgi sox swf tga tiff ts voc voc_s16 wav wtv yuv4mpeg LAVFI_TESTS=crop crop_scale crop_scale_vflip crop_vflip null pixdesc pixfmts_copy pixfmts_crop pixfmts_hflip pixfmts_null pixfmts_pad pixfmts_scale pixfmts_vflip scale200 scale500 vflip vflip_crop vflip_vflip SEEK_TESTS=seek_ac3_rm seek_adpcm_ima_wav seek_adpcm_ms_wav seek_adpcm_qt_aiff seek_adpcm_swf_flv seek_adpcm_yam_wav seek_alac_m4a seek_asv1_avi seek_asv2_avi seek_dnxhd_1080i_mov seek_dnxhd_720p_dnxhd seek_dnxhd_720p_rd_dnxhd seek_dv411_dv seek_dv50_dv seek_dv_dv seek_error_mpeg4_adv_avi seek_ffv1_avi seek_flac_flac seek_flashsv_flv seek_flv_flv seek_g726_wav seek_h261_avi seek_h263_avi seek_h263p_avi seek_huffyuv_avi seek_image_bmp seek_image_jpg seek_image_pcx seek_image_pgm seek_image_ppm seek_image_sgi seek_image_tga seek_image_tiff seek_jpegls_avi seek_lavf_aif seek_lavf_al seek_lavf_asf seek_lavf_au seek_lavf_avi seek_lavf_dv seek_lavf_ffm seek_lavf_flv seek_lavf_gif seek_lavf_gxf seek_lavf_mkv seek_lavf_mmf seek_lavf_mov seek_lavf_mpg seek_lavf_mxf seek_lavf_mxf_d10 seek_lavf_nut seek_lavf_ogg seek_lavf_rm seek_lavf_swf seek_lavf_ts seek_lavf_ul seek_lavf_voc seek_lavf_wav seek_lavf_wtv seek_lavf_y4m seek_ljpeg_avi seek_mjpeg_avi seek_mp2_mp2 seek_mpeg1_mpg seek_mpeg1b_mpg seek_mpeg2_422_mpg seek_mpeg2_idct_int_mpg seek_mpeg2i_mpg seek_mpeg2ivlc_qprd_mpg seek_mpeg2reuse_mpg seek_mpeg2thread_mpg seek_mpeg2threadivlc_mpg seek_mpeg4_adap_avi seek_mpeg4_adv_avi seek_mpeg4_nr_avi seek_mpeg4_qprd_avi seek_mpeg4_rc_avi seek_mpeg4_thread_avi seek_msmpeg4_avi seek_msmpeg4v2_avi seek_odivx_mp4 seek_pbmpipe_pbm seek_pcm_alaw_wav seek_pcm_f32be_au seek_pcm_f32le_wav seek_pcm_f64be_au seek_pcm_f64le_wav seek_pcm_mulaw_wav seek_pcm_s16be_mov seek_pcm_s16le_wav seek_pcm_s24be_mov seek_pcm_s24daud_302 seek_pcm_s24le_wav seek_pcm_s32be_mov seek_pcm_s32le_wav seek_pcm_s8_mov seek_pcm_u8_wav seek_pgmpipe_pgm seek_ppmpipe_ppm seek_rgb_avi seek_roqav_roq seek_rv10_rm seek_rv20_rm seek_snow53_avi seek_snow_avi seek_svq1_mov seek_wmav1_asf seek_wmav2_asf seek_wmv1_avi seek_wmv2_avi seek_yuv_avi endif # FFMPEG_CONFIG_MAK
config.mak代码大致可以分为以下几类信息：
（1）各种路径（prefix等）
（2）工具集（arch、cc、ld、yasm等）
（3）参数集（cppflag、cflag、ldflag等）
（4）前缀后缀（.a、.dll、.exe等）
（5）类库版本（libavXXX_version信息）
（6）组件配置。这一部分信息使用{组件名}=yes的方式进行书写。对于不支持的组件，则在该组件所在行的前面标记上“！”号（感叹号似乎在Makefile语法中并没有什么特殊的用意，此处可能仅仅是作为一种标记？）。这一部分可以分为3类信息：
a) ARCH_信息b) HAVE_信息c) CONFIG_信息。这一部分内容最多，将近有1000行。
（7）Test信息（测试组件的结果？还没研究）
libavXXXX/Makefile
libavXXXX/Makefile指的是FFmpeg类库（libavformat、libavcodec、libavutil等）所在的文件夹下的Makefile。例如libavformat文件夹下的Makefile代码如下所示。# FFmpeg Libavformat Makefile # # 注释：雷霄骅 # [email protected] # http://blog.csdn.net/leixiaohua1020 # # FFmpeg中libavformat的Makefile。 # 注意该Makefile并没有定义类库的编译规则（这一部分统一在library.mak中完成）。 # 该Makefile中只是赋值了几个重要的字符串： # NAME，FFLIBS，HEADERS，OBJS，OBJS-yes #重要：包含了configure信息，位于上一级目录 include $(SUBDIR)../config.mak #名称 NAME = avformat #用到的库？ FFLIBS = avcodec avutil #SDK中的头文件 HEADERS = avformat.h avio.h version.h #OBJS存储的是必须的目标文件 OBJS = allformats.o \ cutils.o \ id3v1.o \ id3v2.o \ metadata.o \ options.o \ os_support.o \ sdp.o \ seek.o \ utils.o \ #OBJS-yes存储的是可选的目标文件 OBJS-$(CONFIG_NETWORK) += network.o # muxers/demuxers OBJS-$(CONFIG_A64_MUXER) += a64.o OBJS-$(CONFIG_AAC_DEMUXER) += aacdec.o rawdec.o OBJS-$(CONFIG_AC3_DEMUXER) += ac3dec.o rawdec.o OBJS-$(CONFIG_AC3_MUXER) += rawenc.o OBJS-$(CONFIG_ACT_DEMUXER) += act.o OBJS-$(CONFIG_ADF_DEMUXER) += bintext.o sauce.o OBJS-$(CONFIG_ADX_DEMUXER) += adxdec.o OBJS-$(CONFIG_ADX_MUXER) += rawenc.o OBJS-$(CONFIG_ADTS_MUXER) += adtsenc.o OBJS-$(CONFIG_AEA_DEMUXER) += aea.o pcm.o OBJS-$(CONFIG_AIFF_DEMUXER) += aiffdec.o riff.o pcm.o isom.o OBJS-$(CONFIG_AIFF_MUXER) += aiffenc.o riff.o isom.o OBJS-$(CONFIG_AMR_DEMUXER) += amr.o OBJS-$(CONFIG_AMR_MUXER) += amr.o OBJS-$(CONFIG_ANM_DEMUXER) += anm.o OBJS-$(CONFIG_APC_DEMUXER) += apc.o OBJS-$(CONFIG_APE_DEMUXER) += ape.o apetag.o OBJS-$(CONFIG_APPLEHTTP_DEMUXER) += applehttp.o OBJS-$(CONFIG_ASF_DEMUXER) += asfdec.o asf.o asfcrypt.o \ riff.o avlanguage.o OBJS-$(CONFIG_ASF_MUXER) += asfenc.o asf.o riff.o OBJS-$(CONFIG_ASS_DEMUXER) += assdec.o OBJS-$(CONFIG_ASS_MUXER) += assenc.o OBJS-$(CONFIG_AU_DEMUXER) += au.o pcm.o OBJS-$(CONFIG_AU_MUXER) += au.o OBJS-$(CONFIG_AVI_DEMUXER) += avidec.o riff.o OBJS-$(CONFIG_AVI_MUXER) += avienc.o riff.o OBJS-$(CONFIG_AVISYNTH) += avisynth.o OBJS-$(CONFIG_AVM2_MUXER) += swfenc.o OBJS-$(CONFIG_AVS_DEMUXER) += avs.o vocdec.o voc.o OBJS-$(CONFIG_BETHSOFTVID_DEMUXER) += bethsoftvid.o OBJS-$(CONFIG_BFI_DEMUXER) += bfi.o OBJS-$(CONFIG_BINK_DEMUXER) += bink.o OBJS-$(CONFIG_BINTEXT_DEMUXER) += bintext.o sauce.o OBJS-$(CONFIG_BIT_DEMUXER) += bit.o OBJS-$(CONFIG_BIT_MUXER) += bit.o OBJS-$(CONFIG_BMV_DEMUXER) += bmv.o OBJS-$(CONFIG_C93_DEMUXER) += c93.o vocdec.o voc.o OBJS-$(CONFIG_CAF_DEMUXER) += cafdec.o caf.o mov.o mov_chan.o \ riff.o isom.o OBJS-$(CONFIG_CAF_MUXER) += cafenc.o caf.o riff.o isom.o OBJS-$(CONFIG_CAVSVIDEO_DEMUXER) += cavsvideodec.o rawdec.o OBJS-$(CONFIG_CAVSVIDEO_MUXER) += rawenc.o OBJS-$(CONFIG_CDG_DEMUXER) += cdg.o OBJS-$(CONFIG_CRC_MUXER) += crcenc.o OBJS-$(CONFIG_DAUD_DEMUXER) += daud.o OBJS-$(CONFIG_DAUD_MUXER) += daud.o OBJS-$(CONFIG_DFA_DEMUXER) += dfa.o OBJS-$(CONFIG_DIRAC_DEMUXER) += diracdec.o rawdec.o OBJS-$(CONFIG_DIRAC_MUXER) += rawenc.o OBJS-$(CONFIG_DNXHD_DEMUXER) += dnxhddec.o rawdec.o OBJS-$(CONFIG_DNXHD_MUXER) += rawenc.o OBJS-$(CONFIG_DSICIN_DEMUXER) += dsicin.o OBJS-$(CONFIG_DTS_DEMUXER) += dtsdec.o rawdec.o OBJS-$(CONFIG_DTS_MUXER) += rawenc.o OBJS-$(CONFIG_DV_DEMUXER) += dv.o OBJS-$(CONFIG_DV_MUXER) += dvenc.o OBJS-$(CONFIG_DXA_DEMUXER) += dxa.o riff.o OBJS-$(CONFIG_EA_CDATA_DEMUXER) += eacdata.o OBJS-$(CONFIG_EA_DEMUXER) += electronicarts.o OBJS-$(CONFIG_EAC3_DEMUXER) += ac3dec.o rawdec.o OBJS-$(CONFIG_EAC3_MUXER) += rawenc.o OBJS-$(CONFIG_FFM_DEMUXER) += ffmdec.o OBJS-$(CONFIG_FFM_MUXER) += ffmenc.o OBJS-$(CONFIG_FFMETADATA_DEMUXER) += ffmetadec.o OBJS-$(CONFIG_FFMETADATA_MUXER) += ffmetaenc.o OBJS-$(CONFIG_FILMSTRIP_DEMUXER) += filmstripdec.o OBJS-$(CONFIG_FILMSTRIP_MUXER) += filmstripenc.o OBJS-$(CONFIG_FLAC_DEMUXER) += flacdec.o rawdec.o \ oggparsevorbis.o \ vorbiscomment.o OBJS-$(CONFIG_FLAC_MUXER) += flacenc.o flacenc_header.o \ vorbiscomment.o OBJS-$(CONFIG_FLIC_DEMUXER) += flic.o OBJS-$(CONFIG_FLV_DEMUXER) += flvdec.o OBJS-$(CONFIG_FLV_MUXER) += flvenc.o avc.o OBJS-$(CONFIG_FOURXM_DEMUXER) += 4xm.o OBJS-$(CONFIG_FRAMECRC_MUXER) += framecrcenc.o OBJS-$(CONFIG_FRAMEMD5_MUXER) += md5enc.o OBJS-$(CONFIG_GIF_MUXER) += gif.o OBJS-$(CONFIG_GSM_DEMUXER) += gsmdec.o OBJS-$(CONFIG_GXF_DEMUXER) += gxf.o OBJS-$(CONFIG_GXF_MUXER) += gxfenc.o audiointerleave.o OBJS-$(CONFIG_G722_DEMUXER) += rawdec.o OBJS-$(CONFIG_G722_MUXER) += rawenc.o OBJS-$(CONFIG_G723_1_DEMUXER) += g723_1.o OBJS-$(CONFIG_G723_1_MUXER) += rawenc.o OBJS-$(CONFIG_G729_DEMUXER) += g729dec.o OBJS-$(CONFIG_H261_DEMUXER) += h261dec.o rawdec.o OBJS-$(CONFIG_H261_MUXER) += rawenc.o OBJS-$(CONFIG_H263_DEMUXER) += h263dec.o rawdec.o OBJS-$(CONFIG_H263_MUXER) += rawenc.o OBJS-$(CONFIG_H264_DEMUXER) += h264dec.o rawdec.o OBJS-$(CONFIG_H264_MUXER) += rawenc.o OBJS-$(CONFIG_ICO_DEMUXER) += icodec.o OBJS-$(CONFIG_IDCIN_DEMUXER) += idcin.o OBJS-$(CONFIG_IDF_DEMUXER) += bintext.o OBJS-$(CONFIG_IFF_DEMUXER) += iff.o OBJS-$(CONFIG_IMAGE2_DEMUXER) += img2.o OBJS-$(CONFIG_IMAGE2_MUXER) += img2.o OBJS-$(CONFIG_IMAGE2PIPE_DEMUXER) += img2.o OBJS-$(CONFIG_IMAGE2PIPE_MUXER) += img2.o OBJS-$(CONFIG_INGENIENT_DEMUXER) += ingenientdec.o rawdec.o OBJS-$(CONFIG_IPMOVIE_DEMUXER) += ipmovie.o OBJS-$(CONFIG_ISS_DEMUXER) += iss.o OBJS-$(CONFIG_IV8_DEMUXER) += iv8.o OBJS-$(CONFIG_IVF_DEMUXER) += ivfdec.o riff.o OBJS-$(CONFIG_IVF_MUXER) += ivfenc.o OBJS-$(CONFIG_JV_DEMUXER) += jvdec.o OBJS-$(CONFIG_LATM_DEMUXER) += rawdec.o OBJS-$(CONFIG_LATM_MUXER) += latmenc.o OBJS-$(CONFIG_LMLM4_DEMUXER) += lmlm4.o OBJS-$(CONFIG_LOAS_DEMUXER) += loasdec.o OBJS-$(CONFIG_LXF_DEMUXER) += lxfdec.o OBJS-$(CONFIG_M4V_DEMUXER) += m4vdec.o rawdec.o OBJS-$(CONFIG_M4V_MUXER) += rawenc.o OBJS-$(CONFIG_MATROSKA_DEMUXER) += matroskadec.o matroska.o \ riff.o isom.o rmdec.o rm.o OBJS-$(CONFIG_MATROSKA_MUXER) += matroskaenc.o matroska.o \ riff.o isom.o avc.o \ flacenc_header.o avlanguage.o OBJS-$(CONFIG_MD5_MUXER) += md5enc.o OBJS-$(CONFIG_MICRODVD_DEMUXER) += microdvddec.o OBJS-$(CONFIG_MICRODVD_MUXER) += microdvdenc.o rawenc.o OBJS-$(CONFIG_MJPEG_DEMUXER) += rawdec.o OBJS-$(CONFIG_MJPEG_MUXER) += rawenc.o OBJS-$(CONFIG_MLP_DEMUXER) += rawdec.o OBJS-$(CONFIG_MLP_MUXER) += rawenc.o OBJS-$(CONFIG_MM_DEMUXER) += mm.o OBJS-$(CONFIG_MMF_DEMUXER) += mmf.o pcm.o OBJS-$(CONFIG_MMF_MUXER) += mmf.o riff.o OBJS-$(CONFIG_MOV_DEMUXER) += mov.o riff.o isom.o mov_chan.o OBJS-$(CONFIG_MOV_MUXER) += movenc.o riff.o isom.o avc.o \ movenchint.o rtpenc_chain.o \ mov_chan.o OBJS-$(CONFIG_MP2_MUXER) += mp3enc.o rawenc.o OBJS-$(CONFIG_MP3_DEMUXER) += mp3dec.o OBJS-$(CONFIG_MP3_MUXER) += mp3enc.o rawenc.o id3v2enc.o OBJS-$(CONFIG_MPC_DEMUXER) += mpc.o apetag.o OBJS-$(CONFIG_MPC8_DEMUXER) += mpc8.o OBJS-$(CONFIG_MPEG1SYSTEM_MUXER) += mpegenc.o OBJS-$(CONFIG_MPEG1VCD_MUXER) += mpegenc.o OBJS-$(CONFIG_MPEG2DVD_MUXER) += mpegenc.o OBJS-$(CONFIG_MPEG2VOB_MUXER) += mpegenc.o OBJS-$(CONFIG_MPEG2SVCD_MUXER) += mpegenc.o OBJS-$(CONFIG_MPEG1VIDEO_MUXER) += rawenc.o OBJS-$(CONFIG_MPEG2VIDEO_MUXER) += rawenc.o OBJS-$(CONFIG_MPEGPS_DEMUXER) += mpeg.o OBJS-$(CONFIG_MPEGTS_DEMUXER) += mpegts.o isom.o OBJS-$(CONFIG_MPEGTS_MUXER) += mpegtsenc.o adtsenc.o OBJS-$(CONFIG_MPEGVIDEO_DEMUXER) += mpegvideodec.o rawdec.o OBJS-$(CONFIG_MPJPEG_MUXER) += mpjpeg.o OBJS-$(CONFIG_MSNWC_TCP_DEMUXER) += msnwc_tcp.o OBJS-$(CONFIG_MTV_DEMUXER) += mtv.o OBJS-$(CONFIG_MVI_DEMUXER) += mvi.o OBJS-$(CONFIG_MXF_DEMUXER) += mxfdec.o mxf.o OBJS-$(CONFIG_MXF_MUXER) += mxfenc.o mxf.o audiointerleave.o OBJS-$(CONFIG_MXG_DEMUXER) += mxg.o OBJS-$(CONFIG_NC_DEMUXER) += ncdec.o OBJS-$(CONFIG_NSV_DEMUXER) += nsvdec.o OBJS-$(CONFIG_NULL_MUXER) += nullenc.o OBJS-$(CONFIG_NUT_DEMUXER) += nutdec.o nut.o riff.o OBJS-$(CONFIG_NUT_MUXER) += nutenc.o nut.o riff.o OBJS-$(CONFIG_NUV_DEMUXER) += nuv.o riff.o OBJS-$(CONFIG_OGG_DEMUXER) += oggdec.o \ oggparsecelt.o \ oggparsedirac.o \ oggparseflac.o \ oggparseogm.o \ oggparseskeleton.o \ oggparsespeex.o \ oggparsetheora.o \ oggparsevorbis.o \ riff.o \ vorbiscomment.o OBJS-$(CONFIG_OGG_MUXER) += oggenc.o \ vorbiscomment.o OBJS-$(CONFIG_OMA_DEMUXER) += omadec.o pcm.o oma.o OBJS-$(CONFIG_OMA_MUXER) += omaenc.o rawenc.o oma.o id3v2enc.o OBJS-$(CONFIG_PCM_ALAW_DEMUXER) += pcmdec.o pcm.o rawdec.o OBJS-$(CONFIG_PCM_ALAW_MUXER) += pcmenc.o rawenc.o OBJS-$(CONFIG_PCM_F32BE_DEMUXER) += pcmdec.o pcm.o rawdec.o OBJS-$(CONFIG_PCM_F32BE_MUXER) += pcmenc.o rawenc.o OBJS-$(CONFIG_PCM_F32LE_DEMUXER) += pcmdec.o pcm.o rawdec.o OBJS-$(CONFIG_PCM_F32LE_MUXER) += pcmenc.o rawenc.o OBJS-$(CONFIG_PCM_F64BE_DEMUXER) += pcmdec.o pcm.o rawdec.o OBJS-$(CONFIG_PCM_F64BE_MUXER) += pcmenc.o rawenc.o OBJS-$(CONFIG_PCM_F64LE_DEMUXER) += pcmdec.o pcm.o rawdec.o OBJS-$(CONFIG_PCM_F64LE_MUXER) += pcmenc.o rawenc.o OBJS-$(CONFIG_PCM_MULAW_DEMUXER) += pcmdec.o pcm.o rawdec.o OBJS-$(CONFIG_PCM_MULAW_MUXER) += pcmenc.o rawenc.o OBJS-$(CONFIG_PCM_S16BE_DEMUXER) += pcmdec.o pcm.o rawdec.o OBJS-$(CONFIG_PCM_S16BE_MUXER) += pcmenc.o rawenc.o OBJS-$(CONFIG_PCM_S16LE_DEMUXER) += pcmdec.o pcm.o rawdec.o OBJS-$(CONFIG_PCM_S16LE_MUXER) += pcmenc.o rawenc.o OBJS-$(CONFIG_PCM_S24BE_DEMUXER) += pcmdec.o pcm.o rawdec.o OBJS-$(CONFIG_PCM_S24BE_MUXER) += pcmenc.o rawenc.o OBJS-$(CONFIG_PCM_S24LE_DEMUXER) += pcmdec.o pcm.o rawdec.o OBJS-$(CONFIG_PCM_S24LE_MUXER) += pcmenc.o rawenc.o OBJS-$(CONFIG_PCM_S32BE_DEMUXER) += pcmdec.o pcm.o rawdec.o OBJS-$(CONFIG_PCM_S32BE_MUXER) += pcmenc.o rawenc.o OBJS-$(CONFIG_PCM_S32LE_DEMUXER) += pcmdec.o pcm.o rawdec.o OBJS-$(CONFIG_PCM_S32LE_MUXER) += pcmenc.o rawenc.o OBJS-$(CONFIG_PCM_S8_DEMUXER) += pcmdec.o pcm.o rawdec.o OBJS-$(CONFIG_PCM_S8_MUXER) += pcmenc.o rawenc.o OBJS-$(CONFIG_PCM_U16BE_DEMUXER) += pcmdec.o pcm.o rawdec.o OBJS-$(CONFIG_PCM_U16BE_MUXER) += pcmenc.o rawenc.o OBJS-$(CONFIG_PCM_U16LE_DEMUXER) += pcmdec.o pcm.o rawdec.o OBJS-$(CONFIG_PCM_U16LE_MUXER) += pcmenc.o rawenc.o OBJS-$(CONFIG_PCM_U24BE_DEMUXER) += pcmdec.o pcm.o rawdec.o OBJS-$(CONFIG_PCM_U24BE_MUXER) += pcmenc.o rawenc.o OBJS-$(CONFIG_PCM_U24LE_DEMUXER) += pcmdec.o pcm.o rawdec.o OBJS-$(CONFIG_PCM_U24LE_MUXER) += pcmenc.o rawenc.o OBJS-$(CONFIG_PCM_U32BE_DEMUXER) += pcmdec.o pcm.o rawdec.o OBJS-$(CONFIG_PCM_U32BE_MUXER) += pcmenc.o rawenc.o OBJS-$(CONFIG_PCM_U32LE_DEMUXER) += pcmdec.o pcm.o rawdec.o OBJS-$(CONFIG_PCM_U32LE_MUXER) += pcmenc.o rawenc.o OBJS-$(CONFIG_PCM_U8_DEMUXER) += pcmdec.o pcm.o rawdec.o OBJS-$(CONFIG_PCM_U8_MUXER) += pcmenc.o rawenc.o OBJS-$(CONFIG_PMP_DEMUXER) += pmpdec.o OBJS-$(CONFIG_PVA_DEMUXER) += pva.o OBJS-$(CONFIG_QCP_DEMUXER) += qcp.o OBJS-$(CONFIG_R3D_DEMUXER) += r3d.o OBJS-$(CONFIG_RAWVIDEO_DEMUXER) += rawvideodec.o rawdec.o OBJS-$(CONFIG_RAWVIDEO_MUXER) += rawenc.o OBJS-$(CONFIG_RL2_DEMUXER) += rl2.o OBJS-$(CONFIG_RM_DEMUXER) += rmdec.o rm.o OBJS-$(CONFIG_RM_MUXER) += rmenc.o rm.o OBJS-$(CONFIG_ROQ_DEMUXER) += idroqdec.o OBJS-$(CONFIG_ROQ_MUXER) += idroqenc.o rawenc.o OBJS-$(CONFIG_RSO_DEMUXER) += rsodec.o rso.o pcm.o OBJS-$(CONFIG_RSO_MUXER) += rsoenc.o rso.o OBJS-$(CONFIG_RPL_DEMUXER) += rpl.o OBJS-$(CONFIG_RTP_MUXER) += rtp.o \ rtpenc_aac.o \ rtpenc_latm.o \ rtpenc_amr.o \ rtpenc_h263.o \ rtpenc_mpv.o \ rtpenc.o \ rtpenc_h264.o \ rtpenc_vp8.o \ rtpenc_xiph.o \ avc.o OBJS-$(CONFIG_RTPDEC) += rdt.o \ rtp.o \ rtpdec.o \ rtpdec_amr.o \ rtpdec_asf.o \ rtpdec_g726.o \ rtpdec_h263.o \ rtpdec_h264.o \ rtpdec_latm.o \ rtpdec_mpeg4.o \ rtpdec_qcelp.o \ rtpdec_qdm2.o \ rtpdec_qt.o \ rtpdec_svq3.o \ rtpdec_vp8.o \ rtpdec_xiph.o OBJS-$(CONFIG_RTSP_DEMUXER) += rtsp.o rtspdec.o httpauth.o OBJS-$(CONFIG_RTSP_MUXER) += rtsp.o rtspenc.o httpauth.o \ rtpenc_chain.o OBJS-$(CONFIG_SAP_DEMUXER) += sapdec.o OBJS-$(CONFIG_SAP_MUXER) += sapenc.o rtpenc_chain.o OBJS-$(CONFIG_SBG_DEMUXER) += sbgdec.o OBJS-$(CONFIG_SDP_DEMUXER) += rtsp.o OBJS-$(CONFIG_SEGAFILM_DEMUXER) += segafilm.o OBJS-$(CONFIG_SEGMENT_MUXER) += segment.o OBJS-$(CONFIG_SHORTEN_DEMUXER) += rawdec.o OBJS-$(CONFIG_SIFF_DEMUXER) += siff.o OBJS-$(CONFIG_SMACKER_DEMUXER) += smacker.o OBJS-$(CONFIG_SMJPEG_DEMUXER) += smjpegdec.o smjpeg.o OBJS-$(CONFIG_SMJPEG_MUXER) += smjpegenc.o smjpeg.o OBJS-$(CONFIG_SOL_DEMUXER) += sol.o pcm.o OBJS-$(CONFIG_SOX_DEMUXER) += soxdec.o pcm.o OBJS-$(CONFIG_SOX_MUXER) += soxenc.o OBJS-$(CONFIG_SPDIF_DEMUXER) += spdif.o spdifdec.o OBJS-$(CONFIG_SPDIF_MUXER) += spdif.o spdifenc.o OBJS-$(CONFIG_SRT_DEMUXER) += srtdec.o OBJS-$(CONFIG_SRT_MUXER) += rawenc.o OBJS-$(CONFIG_STR_DEMUXER) += psxstr.o OBJS-$(CONFIG_SWF_DEMUXER) += swfdec.o OBJS-$(CONFIG_SWF_MUXER) += swfenc.o OBJS-$(CONFIG_THP_DEMUXER) += thp.o OBJS-$(CONFIG_TIERTEXSEQ_DEMUXER) += tiertexseq.o OBJS-$(CONFIG_MKVTIMESTAMP_V2_MUXER) += mkvtimestamp_v2.o OBJS-$(CONFIG_TMV_DEMUXER) += tmv.o OBJS-$(CONFIG_TRUEHD_DEMUXER) += rawdec.o OBJS-$(CONFIG_TRUEHD_MUXER) += rawenc.o OBJS-$(CONFIG_TTA_DEMUXER) += tta.o OBJS-$(CONFIG_TTY_DEMUXER) += tty.o sauce.o OBJS-$(CONFIG_TXD_DEMUXER) += txd.o OBJS-$(CONFIG_VC1_DEMUXER) += rawdec.o OBJS-$(CONFIG_VC1T_DEMUXER) += vc1test.o OBJS-$(CONFIG_VC1T_MUXER) += vc1testenc.o OBJS-$(CONFIG_VMD_DEMUXER) += sierravmd.o OBJS-$(CONFIG_VOC_DEMUXER) += vocdec.o voc.o OBJS-$(CONFIG_VOC_MUXER) += vocenc.o voc.o OBJS-$(CONFIG_VQF_DEMUXER) += vqf.o OBJS-$(CONFIG_W64_DEMUXER) += wav.o riff.o pcm.o OBJS-$(CONFIG_WAV_DEMUXER) += wav.o riff.o pcm.o OBJS-$(CONFIG_WAV_MUXER) += wav.o riff.o OBJS-$(CONFIG_WC3_DEMUXER) += wc3movie.o OBJS-$(CONFIG_WEBM_MUXER) += matroskaenc.o matroska.o \ riff.o isom.o avc.o \ flacenc_header.o avlanguage.o OBJS-$(CONFIG_WSAUD_DEMUXER) += westwood_aud.o OBJS-$(CONFIG_WSVQA_DEMUXER) += westwood_vqa.o OBJS-$(CONFIG_WTV_DEMUXER) += wtvdec.o wtv.o asfdec.o asf.o asfcrypt.o \ avlanguage.o mpegts.o isom.o riff.o OBJS-$(CONFIG_WTV_MUXER) += wtvenc.o wtv.o asf.o asfenc.o riff.o OBJS-$(CONFIG_WV_DEMUXER) += wv.o apetag.o OBJS-$(CONFIG_XA_DEMUXER) += xa.o OBJS-$(CONFIG_XBIN_DEMUXER) += bintext.o sauce.o OBJS-$(CONFIG_XMV_DEMUXER) += xmv.o riff.o OBJS-$(CONFIG_XWMA_DEMUXER) += xwma.o riff.o OBJS-$(CONFIG_YOP_DEMUXER) += yop.o OBJS-$(CONFIG_YUV4MPEGPIPE_MUXER) += yuv4mpeg.o OBJS-$(CONFIG_YUV4MPEGPIPE_DEMUXER) += yuv4mpeg.o # external libraries OBJS-$(CONFIG_LIBMODPLUG_DEMUXER) += libmodplug.o OBJS-$(CONFIG_LIBNUT_DEMUXER) += libnut.o riff.o OBJS-$(CONFIG_LIBNUT_MUXER) += libnut.o riff.o # protocols I/O OBJS+= avio.o aviobuf.o OBJS-$(CONFIG_APPLEHTTP_PROTOCOL) += applehttpproto.o OBJS-$(CONFIG_CACHE_PROTOCOL) += cache.o OBJS-$(CONFIG_CONCAT_PROTOCOL) += concat.o OBJS-$(CONFIG_CRYPTO_PROTOCOL) += crypto.o OBJS-$(CONFIG_FILE_PROTOCOL) += file.o OBJS-$(CONFIG_GOPHER_PROTOCOL) += gopher.o OBJS-$(CONFIG_HTTP_PROTOCOL) += http.o httpauth.o OBJS-$(CONFIG_HTTPPROXY_PROTOCOL) += http.o httpauth.o OBJS-$(CONFIG_HTTPS_PROTOCOL) += http.o httpauth.o OBJS-$(CONFIG_MMSH_PROTOCOL) += mmsh.o mms.o asf.o OBJS-$(CONFIG_MMST_PROTOCOL) += mmst.o mms.o asf.o OBJS-$(CONFIG_MD5_PROTOCOL) += md5proto.o OBJS-$(CONFIG_PIPE_PROTOCOL) += file.o # external or internal rtmp RTMP-OBJS-$(CONFIG_LIBRTMP) = librtmp.o RTMP-OBJS-$(!CONFIG_LIBRTMP) = rtmpproto.o rtmppkt.o OBJS-$(CONFIG_RTMP_PROTOCOL) += $(RTMP-OBJS-yes) OBJS-$(CONFIG_RTP_PROTOCOL) += rtpproto.o OBJS-$(CONFIG_TCP_PROTOCOL) += tcp.o OBJS-$(CONFIG_TLS_PROTOCOL) += tls.o OBJS-$(CONFIG_UDP_PROTOCOL) += udp.o SKIPHEADERS-$(CONFIG_NETWORK) += network.h rtsp.h TESTPROGS = seek TOOLS = aviocat ismindex pktdumper probetest
从代码可以看出，libavformat文件夹下的Makefile的规则十分简单，并不包含文件之间的依赖关系（依赖关系位于library.mak中），仅仅是设置了几个变量的值：
NAME：类库名称。注意不包含类库前面的“lib”以及类库的后缀。在这里是“avformat”。
FFLIBS：该类库依赖的类库名称。在这里用到了“avcodec”和“avutil”。
HEADERS：该类库导出的头文件。在这里是“avformat.h”，“avio.h”，“version.h”。
OBJS：该类库依赖的目标文件（必须的）。在这里是“utils.o”等等。
OBJS-yes：该类库依赖的目标文件（可选的）。在这里是“flvdec.o”、“flvenc.o”等等。
library.mak
library.mak专门用于存储编译类库的规则，是和libavXXX/Makefile配合使用的。它的源代码如下所示。# FFmpeg library.mak # # 注释：雷霄骅 # [email protected] # http://blog.csdn.net/leixiaohua1020 # # 编译类库(libavformat等)专用的Makefile，其中包含了编译类库的规则。 #【NAME位于每个类库的Makefile】，可以取avcodec，avformat等等 SRC_DIR := $(SRC_PATH)/lib$(NAME) include $(SRC_PATH)/common.mak #这些信息都位于config.mak中 #例如： # libavformat_VERSION=53.31.100 # libavformat_VERSION_MAJOR=53 LIBVERSION := $(lib$(NAME)_VERSION) LIBMAJOR := $(lib$(NAME)_VERSION_MAJOR) INCINSTDIR := $(INCDIR)/lib$(NAME) THIS_LIB := $(SUBDIR)$($(CONFIG_SHARED:yes=S)LIBNAME) all-$(CONFIG_STATIC): $(SUBDIR)$(LIBNAME) all-$(CONFIG_SHARED): $(SUBDIR)$(SLIBNAME) $(SUBDIR)%-test.o: $(SUBDIR)%-test.c $(COMPILE_C) $(SUBDIR)%-test.o: $(SUBDIR)%.c $(COMPILE_C) #汇编？ $(SUBDIR)x86/%.o: $(SUBDIR)x86/%.asm $(YASMDEP) $(YASMFLAGS) -I $(<D)/ -M -o $@ $< > $(@:.o=.d) $(YASM) $(YASMFLAGS) -I $(<D)/ -o $@ $< $(OBJS) $(OBJS:.o=.s) $(SUBDIR)%.ho $(TESTOBJS): CPPFLAGS += -DHAVE_AV_CONFIG_H $(TESTOBJS): CPPFLAGS += -DTEST #【OBJS来自于每个类库的Makefile】 #$@ 表示规则中的目标文件集 #$^ 所有的依赖目标的集合。 #生成静态库？ $(SUBDIR)$(LIBNAME): $(OBJS) $(RM) $@ $(AR) rc $@ $^ $(EXTRAOBJS) $(RANLIB) $@ #安转头文件，根目录的Makefile调用 install-headers: install-lib$(NAME)-headers install-lib$(NAME)-pkgconfig #install-libs-yes被install-libs（位于根目录Makefile）调用 install-libs-$(CONFIG_STATIC): install-lib$(NAME)-static install-libs-$(CONFIG_SHARED): install-lib$(NAME)-shared define RULES $(EXAMPLES) $(TESTPROGS) $(TOOLS): %$(EXESUF): %.o $$(LD) $(LDFLAGS) -o $$@ $$^ -l$(FULLNAME) $(FFEXTRALIBS) $$(ELIBS) $(SUBDIR)$(SLIBNAME): $(SUBDIR)$(SLIBNAME_WITH_MAJOR) $(Q)cd ./$(SUBDIR) && $(LN_S) $(SLIBNAME_WITH_MAJOR) $(SLIBNAME) $(SUBDIR)$(SLIBNAME_WITH_MAJOR): $(OBJS) $(SUBDIR)lib$(NAME).ver $(SLIB_CREATE_DEF_CMD) $$(LD) $(SHFLAGS) $(LDFLAGS) -o $$@ $$(filter %.o,$$^) $(FFEXTRALIBS) $(EXTRAOBJS) $(SLIB_EXTRA_CMD) #SLIBNAME_WITH_MAJOR包含了Major版本号。例如：libavformat-53.dll ifdef SUBDIR $(SUBDIR)$(SLIBNAME_WITH_MAJOR): $(DEP_LIBS) endif #清空 clean:: $(RM) $(addprefix $(SUBDIR),*-example$(EXESUF) *-test$(EXESUF) $(CLEANFILES) $(CLEANSUFFIXES) $(LIBSUFFIXES)) \ $(foreach dir,$(DIRS),$(CLEANSUFFIXES:%=$(SUBDIR)$(dir)/%)) \ $(HOSTOBJS) $(HOSTPROGS) distclean:: clean $(RM) $(DISTCLEANSUFFIXES:%=$(SUBDIR)%) \ $(foreach dir,$(DIRS),$(DISTCLEANSUFFIXES:%=$(SUBDIR)$(dir)/%)) #安装库文件===================== install-lib$(NAME)-shared: $(SUBDIR)$(SLIBNAME) $(Q)mkdir -p "$(SHLIBDIR)" $$(INSTALL) -m 755 $$< "$(SHLIBDIR)/$(SLIB_INSTALL_NAME)" $$(STRIP) "$(SHLIBDIR)/$(SLIB_INSTALL_NAME)" $(Q)$(foreach F,$(SLIB_INSTALL_LINKS),cd "$(SHLIBDIR)" && $(LN_S) $(SLIB_INSTALL_NAME) $(F);) $(if $(SLIB_INSTALL_EXTRA_SHLIB),$$(INSTALL) -m 644 $(SLIB_INSTALL_EXTRA_SHLIB:%=$(SUBDIR)%) "$(SHLIBDIR)") $(if $(SLIB_INSTALL_EXTRA_LIB),$(Q)mkdir -p "$(LIBDIR)") $(if $(SLIB_INSTALL_EXTRA_LIB),$$(INSTALL) -m 644 $(SLIB_INSTALL_EXTRA_LIB:%=$(SUBDIR)%) "$(LIBDIR)") install-lib$(NAME)-static: $(SUBDIR)$(LIBNAME) $(Q)mkdir -p "$(LIBDIR)" $$(INSTALL) -m 644 $$< "$(LIBDIR)" $(LIB_INSTALL_EXTRA_CMD) #安装头文件===================== #-m #权限：644,755,777 #644 rw-r--r-- #755 rwxr-xr-x #777 rwxrwxrwx #从左至右，1-3位数字代表文件所有者的权限，4-6位数字代表同组用户的权限，7-9数字代表其他用户的权限。 #通过4、2、1的组合，得到以下几种权限：0（没有权限）；4（读取权限）；5（4+1 | 读取+执行）；6（4+2 | 读取+写入）；7（4+2+1 | 读取+写入+执行） #addprefix() #$(addprefix src/,foo bar)返回值是“src/foo src/bar”。 #【HEADERS来自于每个类库的Makefile】 #例如libavformat中HEADERS = avformat.h avio.h version.h install-lib$(NAME)-headers: $(addprefix $(SUBDIR),$(HEADERS) $(BUILT_HEADERS)) $(Q)mkdir -p "$(INCINSTDIR)" $$(INSTALL) -m 644 $$^ "$(INCINSTDIR)" install-lib$(NAME)-pkgconfig: $(SUBDIR)lib$(NAME).pc $(Q)mkdir -p "$(LIBDIR)/pkgconfig" $$(INSTALL) -m 644 $$^ "$(LIBDIR)/pkgconfig" #卸载 uninstall-libs:: -$(RM) "$(SHLIBDIR)/$(SLIBNAME_WITH_MAJOR)" \ "$(SHLIBDIR)/$(SLIBNAME)" \ "$(SHLIBDIR)/$(SLIBNAME_WITH_VERSION)" -$(RM) $(SLIB_INSTALL_EXTRA_SHLIB:%="$(SHLIBDIR)"%) -$(RM) $(SLIB_INSTALL_EXTRA_LIB:%="$(LIBDIR)"%) -$(RM) "$(LIBDIR)/$(LIBNAME)" uninstall-headers:: $(RM) $(addprefix "$(INCINSTDIR)/",$(HEADERS)) $(addprefix "$(INCINSTDIR)/",$(BUILT_HEADERS)) $(RM) "$(LIBDIR)/pkgconfig/lib$(NAME).pc" -rmdir "$(INCINSTDIR)" endef $(eval $(RULES)) $(EXAMPLES) $(TESTPROGS) $(TOOLS): $(THIS_LIB) $(DEP_LIBS) $(TESTPROGS): $(SUBDIR)$(LIBNAME) examples: $(EXAMPLES) testprogs: $(TESTPROGS)
library.mak代码中首先包含了common.mak文件。这个文件定义了通用的一些编译规则。然后定义了类库的依赖关系。
此外library.mak中也定义了install-headers，install-lib$(NAME)-shared，install-lib$(NAME)-static，install-lib$(NAME)-headers，clean等等一系列的伪目标（NAME取值avformat、avcodec等）。这些目标主要配合根目录的Makefile使用。
common.mak
common.mak文件定义了通用的一些编译规则。代码如下所示。
# FFmpeg common.mak # # 注释：雷霄骅 # [email protected] # http://blog.csdn.net/leixiaohua1020 # # 通用的Makefile，其中包含了通用的编译规则。 # # common bits used by all libraries # # first so "all" becomes default target all: all-yes ifndef SUBDIR #在控制台打印信息 ifndef V Q = @ #输出 ECHO = printf "$(1)\t%s\n" $(2) BRIEF = CC CXX AS YASM AR LD HOSTCC STRIP CP SILENT = DEPCC YASMDEP RM RANLIB MSG = $@ M = @$(call ECHO,$(TAG),$@); $(foreach VAR,$(BRIEF), \ $(eval override $(VAR) = @$$(call ECHO,$(VAR),$$(MSG)); $($(VAR)))) $(foreach VAR,$(SILENT),$(eval override $(VAR) = @$($(VAR)))) $(eval INSTALL = @$(call ECHO,INSTALL,$$(^:$(SRC_DIR)/%=%)); $(INSTALL)) endif #所有的lib ALLFFLIBS = avcodec avdevice avfilter avformat avutil postproc swscale swresample # NASM requires -I path terminated with / #各种Flag #SRC_PATH=. IFLAGS := -I. -I$(SRC_PATH)/ CPPFLAGS := $(IFLAGS) $(CPPFLAGS) CFLAGS += $(ECFLAGS) CCFLAGS = $(CFLAGS) CXXFLAGS := $(CFLAGS) $(CXXFLAGS) YASMFLAGS += $(IFLAGS) -I$(SRC_PATH)/libavutil/x86/ -Pconfig.asm HOSTCFLAGS += $(IFLAGS) #avcodec处理后成为-Llibavcodec #config.mak文件中： #LDFLAGS= -Wl,--as-needed -Wl,--warn-common -Wl, #-rpath-link=libpostproc:libswresample:libswscale:libavfilter:libavdevice:libavformat:libavcodec:libavutil LDFLAGS := $(ALLFFLIBS:%=-Llib%) $(LDFLAGS) #命令包 #具体编译命令 # #$(1)可以取CC、CXX等 #例如取$(1)取CC #config.mak文件中： #SRC_PATH=. #CC=gcc # #CCFLAGS=$(CFLAGS) #CFLAGS= -std=c99 -fno-common -fomit-frame-pointer -I/include/SDL -D_GNU_SOURCE=1 -Dmain=SDL_main # -g -Wdeclaration-after-statement -Wall -Wno-parentheses -Wno-switch -Wno-format-zero-length # -Wdisabled-optimization -Wpointer-arith -Wredundant-decls -Wno-pointer-sign -Wcast-qual -Wwrite-strings # -Wtype-limits -Wundef -Wmissing-prototypes -Wno-pointer-to-int-cast -Wstrict-prototypes # -O3 -fno-math-errno -fno-signed-zeros -fno-tree-vectorize -Werror=implicit-function-declaration -Werror=missing-prototypes # #CPPFLAGS= -D_ISOC99_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -U__STRICT_ANSI__ #CC_O=-o $@ #CC_DEPFLAGS=-MMD -MF $(@:.o=.d) -MT $@ #举例： #gcc -I. -Itest/ -c -o $@ $< #再例如$(1)取CXX #CXXFLAGS= -D__STDC_CONSTANT_MACROS define COMPILE $($(1)DEP) $($(1)) $(CPPFLAGS) $($(1)FLAGS) $($(1)_DEPFLAGS) -c $($(1)_O) $< endef #编译命令 #$(call <expression>,<parm1>,<parm2>,<parm3>...) #当make执行这个函数时，<expression>参数中的变量，如$(1)，$(2)，$(3)等，会被参数 #<parm1>，<parm2>，<parm3>依次取代。而<expression>的返回值就是call函数的返回值。 COMPILE_C = $(call COMPILE,CC) COMPILE_CXX = $(call COMPILE,CXX) COMPILE_S = $(call COMPILE,AS) #COMPILE_C为： #$(CC DEP) #$($(CC) $(CPPFLAGS) $($(1)FLAGS) $($(1)_DEPFLAGS) -c $($(1)_O) $< #依赖关系 #C语言 %.o: %.c #编译 $(COMPILE_C) #C++ %.o: %.cpp $(COMPILE_CXX) %.s: %.c $(CC) $(CPPFLAGS) $(CFLAGS) -S -o $@ $< %.o: %.S $(COMPILE_S) %.ho: %.h $(CC) $(CPPFLAGS) $(CFLAGS) -Wno-unused -c -o $@ -x c $< %.ver: %.v $(Q)sed 's/$$MAJOR/$($(basename $(@F))_VERSION_MAJOR)/' $^ > $@ %.c %.h: TAG = GEN # Dummy rule to stop make trying to rebuild removed or renamed headers %.h: @: # Disable suffix rules. Most of the builtin rules are suffix rules, # so this saves some time on slow systems. .SUFFIXES: # Do not delete intermediate files from chains of implicit rules $(OBJS): endif OBJS-$(HAVE_MMX) += $(MMX-OBJS-yes) #源自Makefile #OBJS：该类库必须的目标文件 #OBJS-yes：该类库可配置的目标文件 OBJS += $(OBJS-yes) #FFLIBS：必须的类库 #FFLIBS-yes：可选的类库 #FFLIBS = avcodec avutil .... FFLIBS := $(FFLIBS-yes) $(FFLIBS) TESTPROGS += $(TESTPROGS-yes) FFEXTRALIBS := $(FFLIBS:%=-l%$(BUILDSUF)) $(EXTRALIBS) EXAMPLES := $(EXAMPLES:%=$(SUBDIR)%-example$(EXESUF)) #排序？ OBJS := $(sort $(OBJS:%=$(SUBDIR)%)) TESTOBJS := $(TESTOBJS:%=$(SUBDIR)%) $(TESTPROGS:%=$(SUBDIR)%-test.o) TESTPROGS := $(TESTPROGS:%=$(SUBDIR)%-test$(EXESUF)) HOSTOBJS := $(HOSTPROGS:%=$(SUBDIR)%.o) HOSTPROGS := $(HOSTPROGS:%=$(SUBDIR)%$(HOSTEXESUF)) TOOLS += $(TOOLS-yes) TOOLOBJS := $(TOOLS:%=tools/%.o) TOOLS := $(TOOLS:%=tools/%$(EXESUF)) #DEP_LIBS= libavcodec/libavcodec.a libavutil/libavutil.a .... DEP_LIBS := $(foreach NAME,$(FFLIBS),lib$(NAME)/$($(CONFIG_SHARED:yes=S)LIBNAME)) ALLHEADERS := $(subst $(SRC_DIR)/,$(SUBDIR),$(wildcard $(SRC_DIR)/*.h $(SRC_DIR)/$(ARCH)/*.h)) SKIPHEADERS += $(ARCH_HEADERS:%=$(ARCH)/%) $(SKIPHEADERS-) SKIPHEADERS := $(SKIPHEADERS:%=$(SUBDIR)%) checkheaders: $(filter-out $(SKIPHEADERS:.h=.ho),$(ALLHEADERS:.h=.ho)) alltools: $(TOOLS) $(HOSTOBJS): %.o: %.c $(HOSTCC) $(HOSTCFLAGS) -c -o $@ $< $(HOSTPROGS): %$(HOSTEXESUF): %.o $(HOSTCC) $(HOSTLDFLAGS) -o $@ $< $(HOSTLIBS) $(OBJS): | $(sort $(dir $(OBJS))) $(HOSTOBJS): | $(sort $(dir $(HOSTOBJS))) $(TESTOBJS): | $(sort $(dir $(TESTOBJS))) $(TOOLOBJS): | tools OBJDIRS := $(OBJDIRS) $(dir $(OBJS) $(HOSTOBJS) $(TESTOBJS)) CLEANSUFFIXES = *.d *.o *~ *.ho *.map *.ver *.gcno *.gcda DISTCLEANSUFFIXES = *.pc LIBSUFFIXES = *.a *.lib *.so *.so.* *.dylib *.dll *.def *.dll.a *.exp #依赖文件.d（dependence） -include $(wildcard $(OBJS:.o=.d) $(TESTOBJS:.o=.d))
从代码中可以看出，common.mak定义了一些通用的编译规则，例如编译时候的控制台输出格式，编译命令COMPILE_C、COMPILE_CXX、COMPILE_S，以及.c、.o等文件之间的依赖关系等。
雷霄骅
[email protected]
http://blog.csdn.net/leixiaohua1020