FFmpeg源代码简单分析：makefile
来源：互联网 发布：googlenet tensorflow 编辑：程序博客网 时间：2024/06/07 23:04
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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# leixiaohua1020@126.com# 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 $(SRC_PATH)#CONFIG_XXX取值为yes#PROGS-yes= ffmpeg ffplay ffprobePROGS-$(CONFIG_FFMPEG) += ffmpegPROGS-$(CONFIG_FFPLAY) += ffplayPROGS-$(CONFIG_FFPROBE) += ffprobePROGS-$(CONFIG_FFSERVER) += ffserver#config.mak中：#EXESUF=.exe#PROGSSUF=#$(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.oTESTTOOLS = audiogen videogen rotozoom tiny_psnr base64HOSTPROGS := $(TESTTOOLS:%=tests/%)TOOLS = qt-faststart trasherTOOLS-$(CONFIG_ZLIB) += cws2fws#PROGS= ffmpeg.exe ffplay.exe ffprobe.exe#INSTPROGS= ffmpeg.exe ffplay.exe ffprobe.exe#OBJS= ffmpeg.o ffplay.o ffprobe.oBASENAMES = ffmpeg ffplay ffprobe ffserverALLPROGS = $(BASENAMES:%=%$(PROGSSUF)$(EXESUF))ALLPROGS_G = $(BASENAMES:%=%$(PROGSSUF)_g$(EXESUF))ALLMANPAGES = $(BASENAMES:%=%.1)#ALLPROGS= ffmpeg.exe ffplay.exe ffprobe.exe ffserver.exe#ALLPROGS_G= ffmpeg_g.exe ffplay_g.exe ffprobe_g.exe ffserver_g.exe#ALLMANPAGES=ffmpeg.1 ffplay.1 ffprobe.1 ffserver.1FFLIBS-$(CONFIG_AVDEVICE) += avdeviceFFLIBS-$(CONFIG_AVFILTER) += avfilterFFLIBS-$(CONFIG_AVFORMAT) += avformatFFLIBS-$(CONFIG_AVCODEC) += avcodecFFLIBS-$(CONFIG_POSTPROC) += postprocFFLIBS-$(CONFIG_SWRESAMPLE)+= swresampleFFLIBS-$(CONFIG_SWSCALE) += swscale#FFLIBS-yes= avdevice avfilter avformat avcodec postproc swresample swscale#一定需要libavutilFFLIBS := 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.xsdSKIPHEADERS = 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 = -lzconfig.h: .config.config: $(wildcard $(FFLIBS:%=$(SRC_PATH)/lib%/all*.c))@-tput bold 2>/dev/null@-printf '\nWARNING: $(?F) newer than config.h, rerun configure\n\n'@-tput sgr0 2>/dev/null#给子目录中的Makefile使用的变量SUBDIR_VARS := OBJS FFLIBS CLEANFILES DIRS TESTPROGS EXAMPLES SKIPHEADERS \ ALTIVEC-OBJS MMX-OBJS NEON-OBJS X86-OBJS YASM-OBJS-FFT YASM-OBJS \ HOSTPROGS BUILT_HEADERS TESTOBJS ARCH_HEADERS ARMV6-OBJS TOOLSdefine RESET$(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Makefileinclude $(SRC_PATH)/$(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 $(SRC_PATH)/library.makendef#=================================#$(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SDLffplay.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.shGIT_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 PROGSinstall: install-progs install-dataendif#安装类库和头文件install: install-libs install-headers#install-libs-yes位于library.makinstall-libs: install-libs-yesinstall-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$(RM) -r coverage-htmldistclean::$(RM) $(DISTCLEANSUFFIXES)$(RM) config.* .version version.h libavutil/avconfig.hconfig:$(SRC_PATH)/configure $(value FFMPEG_CONFIGURATION)# Without the sed genthml thinks "libavutil" and "./libavutil" are two different thingscoverage.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/Makefileinclude $(SRC_PATH)/tests/Makefile$(sort $(OBJDIRS)):$(Q)mkdir -p $@# Dummy rule to stop make trying to rebuild removed or renamed headers%.h:@:# Disable suffix rules. Most of the builtin rules are suffix rules,# so this saves some time on slow systems..SUFFIXES:#显示地指明一个目标是“伪目标”.PHONY: all all-yes alltools *clean config examples install*.PHONY: testprogs uninstall*根目录Makefile代码一开始的时候包含了config.mak文件。这个文件是运行./configure的后生成的配置文件，包含了所有的配置信息。
随后代码定义了ffplay.exe，ffmpeg.exe，ffprobe.exe与ffplay_g.exe，ffmpeg_g.exe，ffprobe_g.exe的依赖关系。然后定义了ffplay_g.exe，ffmpeg_g.exe，ffprobe_g.exe与libavformat，libavcodec等这些类库的依赖关系。
根目录Makefile中也定义了all，install，uninstall，clean等等一系列的伪目标，这样可以通过给Makefile指定不同的目标来完成不同的事。
此外根目录的Makefile中有一个很重要的命令包DOSUBDIR。在该命令包通过包含libavXXX/Makefile和library.mak等文件，定义了FFmpeg类库（例如libavformat，libavcodec，libavutil等）的依赖关系。config.mak
config.mak文件是运行./configure的后生成的配置文件，包含了所有的配置信息。简单注释过的config.mak的代码如下所示。# FFmpeg config.mak## 注释：雷霄骅# leixiaohua1020@126.com# http://blog.csdn.net/leixiaohua1020## Configure脚本生成的Makefile，包含了各种配置信息。## Automatically generated by configure - do not modify!#基本信息ifndef FFMPEG_CONFIG_MAKFFMPEG_CONFIG_MAK=1FFMPEG_CONFIGURATION=#各种路径========================================prefix=/usr/localLIBDIR=$(DESTDIR)${prefix}/libSHLIBDIR=$(DESTDIR)${prefix}/binINCDIR=$(DESTDIR)${prefix}/includeBINDIR=$(DESTDIR)${prefix}/binDATADIR=$(DESTDIR)${prefix}/share/ffmpegMANDIR=$(DESTDIR)${prefix}/share/man#是个相对路径SRC_PATH=.ifndef MAIN_MAKEFILESRC_PATH:=$(SRC_PATH:.%=..%)endif#工具集==========================================CC_IDENT=gcc 4.6.2 (GCC)#架构ARCH=x86#编译器CC=gccCXX=g++AS=gcc#链接器LD=gccDEPCC=gcc#汇编器YASM=yasmYASMDEP=yasm#生成静态库.a工具AR=arRANLIB=ranlibCP=cp -pLN_S=ln -sfSTRIP=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-prototypesCXXFLAGS= -D__STDC_CONSTANT_MACROSASFLAGS= -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:libavutilFFSERVERLDFLAGS=-Wl,-ESHFLAGS=-shared -Wl,--output-def,$$(@:$(SLIBSUF)=.def) -Wl,--out-implib,$(SUBDIR)lib$(SLIBNAME:$(SLIBSUF)=.dll.a) -Wl,--enable-runtime-pseudo-reloc -Wl,--enable-auto-image-base -Wl,-Bsymbolic -Wl,--version-script,$(SUBDIR)lib$(NAME).verYASMFLAGS=-f win32 -DPREFIX#前缀后缀========================================BUILDSUF=PROGSSUF=#${NAME}位于每个liavXXX/Makefile中，例如avformatFULLNAME=$(NAME)$(BUILDSUF)LIBPREF=libLIBSUF=.a#例如libavformat.aLIBNAME=$(LIBPREF)$(FULLNAME)$(LIBSUF)SLIBPREF=SLIBSUF=.dllEXESUF=.exeEXTRA_VERSION=DEPFLAGS=$(CPPFLAGS) $(CFLAGS) -MMCCDEP=CXXDEP=$(DEPCC) $(DEPFLAGS) $< | sed -e "/^\#.*/d" -e "s,^[[:space:]]*$(*F)\\.o,$(@D)/$(*F).o," > $(@:.o=.d)ASDEP=CC_DEPFLAGS=-MMD -MF $(@:.o=.d) -MT $@AS_DEPFLAGS=-MMD -MF $(@:.o=.d) -MT $@HOSTCC=gccHOSTCFLAGS=-D_ISOC99_SOURCE -O3 -g -std=c99 -WallHOSTEXESUF=.exeHOSTLDFLAGS=HOSTLIBS=-lmTARGET_EXEC=TARGET_PATH=$(CURDIR)#SDLSDL_LIBS=-L/lib -lmingw32 -lSDLmain -lSDL -mwindowsSDL_CFLAGS=-I/include/SDL -D_GNU_SOURCE=1 -Dmain=SDL_mainLIB_INSTALL_EXTRA_CMD=$$(RANLIB) "$(LIBDIR)/$(LIBNAME)"#链接EXTRALIBS=-lavicap32 -lws2_32 -L/lib -lmingw32 -lSDLmain -lSDL -mwindows -lm -lz -lpsapi INSTALL=installLIBTARGET=i386#例如libavformat.dllSLIBNAME=$(SLIBPREF)$(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)$(SLIBSUF)#例如libavformat-53.31.100.dllSLIBNAME_WITH_MAJOR=$(SLIBPREF)$(FULLNAME)-$(LIBMAJOR)$(SLIBSUF)SLIB_CREATE_DEF_CMD=#生成导出库lib，会调用lib.exeSLIB_EXTRA_CMD=-lib.exe /machine:$(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=53.60.100libavcodec_VERSION_MAJOR=53libavdevice_VERSION=53.4.100libavdevice_VERSION_MAJOR=53libavfilter_VERSION=2.60.100libavfilter_VERSION_MAJOR=2libavformat_VERSION=53.31.100libavformat_VERSION_MAJOR=53libavutil_VERSION=51.34.101libavutil_VERSION_MAJOR=51libpostproc_VERSION=52.0.100libpostproc_VERSION_MAJOR=52libswresample_VERSION=0.6.100libswresample_VERSION_MAJOR=0libswscale_VERSION=2.1.100libswscale_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=yesARCH_X86=yesARCH_X86_32=yes!ARCH_X86_64=yes#HAVE_!HAVE_ALTIVEC=yesHAVE_AMD3DNOW=yesHAVE_AMD3DNOWEXT=yes!HAVE_ARMV5TE=yes!HAVE_ARMV6=yes!HAVE_ARMV6T2=yes!HAVE_ARMVFP=yesHAVE_AVX=yes!HAVE_IWMMXT=yes!HAVE_MMI=yesHAVE_MMX=yesHAVE_MMX2=yes!HAVE_NEON=yes!HAVE_PPC4XX=yesHAVE_SSE=yesHAVE_SSSE3=yes!HAVE_VFPV3=yes!HAVE_VIS=yes!HAVE_BIGENDIAN=yesHAVE_FAST_UNALIGNED=yes!HAVE_PTHREADS=yesHAVE_W32THREADS=yes!HAVE_OS2THREADS=yesHAVE_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=yesHAVE_ATTRIBUTE_MAY_ALIAS=yesHAVE_ATTRIBUTE_PACKED=yesHAVE_CBRTF=yesHAVE_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=yesHAVE_DOS_PATHS=yesHAVE_EBP_AVAILABLE=yesHAVE_EBX_AVAILABLE=yesHAVE_EXP2=yesHAVE_EXP2F=yes!HAVE_FAST_64BIT=yesHAVE_FAST_CLZ=yes!HAVE_FAST_CMOV=yes!HAVE_FCNTL=yes!HAVE_FORK=yes!HAVE_GETADDRINFO=yes!HAVE_GETHRTIME=yesHAVE_GETPROCESSAFFINITYMASK=yesHAVE_GETPROCESSMEMORYINFO=yesHAVE_GETPROCESSTIMES=yes!HAVE_GETRUSAGE=yesHAVE_GNU_AS=yes!HAVE_IBM_ASM=yes!HAVE_INET_ATON=yesHAVE_INLINE_ASM=yesHAVE_ISATTY=yesHAVE_KBHIT=yes!HAVE_LDBRX=yesHAVE_LLRINT=yesHAVE_LLRINTF=yesHAVE_LOCAL_ALIGNED_16=yesHAVE_LOCAL_ALIGNED_8=yes!HAVE_LOCALTIME_R=yesHAVE_LOG2=yesHAVE_LOG2F=yes!HAVE_LOONGSON=yesHAVE_LRINT=yesHAVE_LRINTF=yes!HAVE_LZO1X_999_COMPRESS=yes!HAVE_MACHINE_IOCTL_BT848_H=yes!HAVE_MACHINE_IOCTL_METEOR_H=yesHAVE_MAKEINFO=yesHAVE_MALLOC_H=yesHAVE_MAPVIEWOFFILE=yes!HAVE_MEMALIGN=yes!HAVE_MKSTEMP=yes!HAVE_MMAP=yesHAVE_PEEKNAMEDPIPE=yes!HAVE_POLL_H=yes!HAVE_POSIX_MEMALIGN=yesHAVE_ROUND=yesHAVE_ROUNDF=yes!HAVE_SCHED_GETAFFINITY=yesHAVE_SDL=yesHAVE_SDL_VIDEO_SIZE=yesHAVE_SETMODE=yes!HAVE_SETRLIMIT=yes!HAVE_SNDIO_H=yesHAVE_SOCKLEN_T=yes!HAVE_SOUNDCARD_H=yes!HAVE_STRERROR_R=yes!HAVE_STRPTIME=yesHAVE_STRUCT_ADDRINFO=yesHAVE_STRUCT_IPV6_MREQ=yes!HAVE_STRUCT_RUSAGE_RU_MAXRSS=yesHAVE_STRUCT_SOCKADDR_IN6=yes!HAVE_STRUCT_SOCKADDR_SA_LEN=yesHAVE_STRUCT_SOCKADDR_STORAGE=yes!HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE=yesHAVE_SYMVER=yesHAVE_SYMVER_ASM_LABEL=yes!HAVE_SYMVER_GNU_ASM=yes!HAVE_SYSCONF=yes!HAVE_SYSCTL=yes!HAVE_SYS_MMAN_H=yesHAVE_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=yesHAVE_THREADS=yesHAVE_TRUNC=yesHAVE_TRUNCF=yes!HAVE_VFP_ARGS=yesHAVE_VIRTUALALLOC=yesHAVE_WINSOCK2_H=yes!HAVE_XFORM_ASM=yes!HAVE_XMM_CLOBBERS=yesHAVE_YASM=yes#CONFIG_CONFIG_BSFS=yesCONFIG_DECODERS=yesCONFIG_DEMUXERS=yesCONFIG_ENCODERS=yesCONFIG_FILTERS=yes!CONFIG_HWACCELS=yesCONFIG_INDEVS=yesCONFIG_MUXERS=yesCONFIG_OUTDEVS=yesCONFIG_PARSERS=yesCONFIG_PROTOCOLS=yesCONFIG_FFPLAY=yesCONFIG_FFPROBE=yes!CONFIG_FFSERVER=yesCONFIG_FFMPEG=yes!CONFIG_AVPLAY=yes!CONFIG_AVPROBE=yes!CONFIG_AVSERVER=yesCONFIG_AANDCT=yesCONFIG_AC3DSP=yesCONFIG_AVCODEC=yesCONFIG_AVDEVICE=yesCONFIG_AVFILTER=yesCONFIG_AVFORMAT=yes!CONFIG_AVISYNTH=yes!CONFIG_BZLIB=yes!CONFIG_CRYSTALHD=yesCONFIG_DCT=yes!CONFIG_DOC=yesCONFIG_DWT=yes!CONFIG_DXVA2=yesCONFIG_FASTDIV=yesCONFIG_FFT=yes!CONFIG_FREI0R=yes!CONFIG_GNUTLS=yesCONFIG_GOLOMB=yes!CONFIG_GPL=yes!CONFIG_GRAY=yesCONFIG_H264CHROMA=yesCONFIG_H264DSP=yesCONFIG_H264PRED=yes!CONFIG_HARDCODED_TABLES=yesCONFIG_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=yesCONFIG_LPC=yesCONFIG_LSP=yesCONFIG_MDCT=yesCONFIG_MEMALIGN_HACK=yes!CONFIG_MLIB=yesCONFIG_MPEGAUDIODSP=yesCONFIG_NETWORK=yes!CONFIG_NONFREE=yes!CONFIG_OPENAL=yes!CONFIG_OPENSSL=yes!CONFIG_PIC=yes!CONFIG_POSTPROC=yesCONFIG_RDFT=yesCONFIG_RTPDEC=yes!CONFIG_RUNTIME_CPUDETECT=yesCONFIG_SAFE_BITSTREAM_READER=yes!CONFIG_SHARED=yesCONFIG_SINEWIN=yes!CONFIG_SMALL=yes!CONFIG_SRAM=yesCONFIG_STATIC=yesCONFIG_SWRESAMPLE=yesCONFIG_SWSCALE=yesCONFIG_SWSCALE_ALPHA=yes!CONFIG_THUMB=yes!CONFIG_VAAPI=yes!CONFIG_VDA=yes!CONFIG_VDPAU=yes!CONFIG_VERSION3=yes!CONFIG_X11GRAB=yesCONFIG_ZLIB=yesCONFIG_AVUTIL=yes!CONFIG_GPLV3=yes!CONFIG_LGPLV3=yesCONFIG_AAC_ADTSTOASC_BSF=yesCONFIG_CHOMP_BSF=yesCONFIG_DUMP_EXTRADATA_BSF=yesCONFIG_H264_MP4TOANNEXB_BSF=yesCONFIG_IMX_DUMP_HEADER_BSF=yesCONFIG_MJPEG2JPEG_BSF=yesCONFIG_MJPEGA_DUMP_HEADER_BSF=yesCONFIG_MP3_HEADER_COMPRESS_BSF=yesCONFIG_MP3_HEADER_DECOMPRESS_BSF=yesCONFIG_MOV2TEXTSUB_BSF=yesCONFIG_NOISE_BSF=yesCONFIG_REMOVE_EXTRADATA_BSF=yesCONFIG_TEXT2MOVSUB_BSF=yesCONFIG_AASC_DECODER=yesCONFIG_AMV_DECODER=yesCONFIG_ANM_DECODER=yesCONFIG_ANSI_DECODER=yesCONFIG_ASV1_DECODER=yesCONFIG_ASV2_DECODER=yesCONFIG_AURA_DECODER=yesCONFIG_AURA2_DECODER=yesCONFIG_AVRP_DECODER=yesCONFIG_AVS_DECODER=yesCONFIG_BETHSOFTVID_DECODER=yesCONFIG_BFI_DECODER=yesCONFIG_BINK_DECODER=yesCONFIG_BMP_DECODER=yesCONFIG_BMV_VIDEO_DECODER=yesCONFIG_C93_DECODER=yesCONFIG_CAVS_DECODER=yesCONFIG_CDGRAPHICS_DECODER=yesCONFIG_CINEPAK_DECODER=yesCONFIG_CLJR_DECODER=yesCONFIG_CSCD_DECODER=yesCONFIG_CYUV_DECODER=yesCONFIG_DFA_DECODER=yesCONFIG_DIRAC_DECODER=yesCONFIG_DNXHD_DECODER=yesCONFIG_DPX_DECODER=yesCONFIG_DSICINVIDEO_DECODER=yesCONFIG_DVVIDEO_DECODER=yesCONFIG_DXA_DECODER=yesCONFIG_DXTORY_DECODER=yesCONFIG_EACMV_DECODER=yesCONFIG_EAMAD_DECODER=yesCONFIG_EATGQ_DECODER=yesCONFIG_EATGV_DECODER=yesCONFIG_EATQI_DECODER=yesCONFIG_EIGHTBPS_DECODER=yesCONFIG_EIGHTSVX_EXP_DECODER=yesCONFIG_EIGHTSVX_FIB_DECODER=yesCONFIG_ESCAPE124_DECODER=yesCONFIG_ESCAPE130_DECODER=yesCONFIG_FFV1_DECODER=yesCONFIG_FFVHUFF_DECODER=yesCONFIG_FLASHSV_DECODER=yesCONFIG_FLASHSV2_DECODER=yesCONFIG_FLIC_DECODER=yesCONFIG_FLV_DECODER=yesCONFIG_FOURXM_DECODER=yesCONFIG_FRAPS_DECODER=yesCONFIG_FRWU_DECODER=yesCONFIG_GIF_DECODER=yesCONFIG_H261_DECODER=yesCONFIG_H263_DECODER=yesCONFIG_H263I_DECODER=yesCONFIG_H264_DECODER=yes#此处省略若干条…CONFIG_RTMP_PROTOCOL=yesCONFIG_RTMPT_PROTOCOL=yesCONFIG_RTMPE_PROTOCOL=yesCONFIG_RTMPTE_PROTOCOL=yesCONFIG_RTMPS_PROTOCOL=yesCONFIG_RTP_PROTOCOL=yesCONFIG_TCP_PROTOCOL=yes!CONFIG_TLS_PROTOCOL=yesCONFIG_UDP_PROTOCOL=yes#TestACODEC_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_MAKconfig.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# leixiaohua1020@126.com# 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/demuxersOBJS-$(CONFIG_A64_MUXER) += a64.oOBJS-$(CONFIG_AAC_DEMUXER) += aacdec.o rawdec.oOBJS-$(CONFIG_AC3_DEMUXER) += ac3dec.o rawdec.oOBJS-$(CONFIG_AC3_MUXER) += rawenc.oOBJS-$(CONFIG_ACT_DEMUXER) += act.oOBJS-$(CONFIG_ADF_DEMUXER) += bintext.o sauce.oOBJS-$(CONFIG_ADX_DEMUXER) += adxdec.oOBJS-$(CONFIG_ADX_MUXER) += rawenc.oOBJS-$(CONFIG_ADTS_MUXER) += adtsenc.oOBJS-$(CONFIG_AEA_DEMUXER) += aea.o pcm.oOBJS-$(CONFIG_AIFF_DEMUXER) += aiffdec.o riff.o pcm.o isom.oOBJS-$(CONFIG_AIFF_MUXER) += aiffenc.o riff.o isom.oOBJS-$(CONFIG_AMR_DEMUXER) += amr.oOBJS-$(CONFIG_AMR_MUXER) += amr.oOBJS-$(CONFIG_ANM_DEMUXER) += anm.oOBJS-$(CONFIG_APC_DEMUXER) += apc.oOBJS-$(CONFIG_APE_DEMUXER) += ape.o apetag.oOBJS-$(CONFIG_APPLEHTTP_DEMUXER) += applehttp.oOBJS-$(CONFIG_ASF_DEMUXER) += asfdec.o asf.o asfcrypt.o \ riff.o avlanguage.oOBJS-$(CONFIG_ASF_MUXER) += asfenc.o asf.o riff.oOBJS-$(CONFIG_ASS_DEMUXER) += assdec.oOBJS-$(CONFIG_ASS_MUXER) += assenc.oOBJS-$(CONFIG_AU_DEMUXER) += au.o pcm.oOBJS-$(CONFIG_AU_MUXER) += au.oOBJS-$(CONFIG_AVI_DEMUXER) += avidec.o riff.oOBJS-$(CONFIG_AVI_MUXER) += avienc.o riff.oOBJS-$(CONFIG_AVISYNTH) += avisynth.oOBJS-$(CONFIG_AVM2_MUXER) += swfenc.oOBJS-$(CONFIG_AVS_DEMUXER) += avs.o vocdec.o voc.oOBJS-$(CONFIG_BETHSOFTVID_DEMUXER) += bethsoftvid.oOBJS-$(CONFIG_BFI_DEMUXER) += bfi.oOBJS-$(CONFIG_BINK_DEMUXER) += bink.oOBJS-$(CONFIG_BINTEXT_DEMUXER) += bintext.o sauce.oOBJS-$(CONFIG_BIT_DEMUXER) += bit.oOBJS-$(CONFIG_BIT_MUXER) += bit.oOBJS-$(CONFIG_BMV_DEMUXER) += bmv.oOBJS-$(CONFIG_C93_DEMUXER) += c93.o vocdec.o voc.oOBJS-$(CONFIG_CAF_DEMUXER) += cafdec.o caf.o mov.o mov_chan.o \ riff.o isom.oOBJS-$(CONFIG_CAF_MUXER) += cafenc.o caf.o riff.o isom.oOBJS-$(CONFIG_CAVSVIDEO_DEMUXER) += cavsvideodec.o rawdec.oOBJS-$(CONFIG_CAVSVIDEO_MUXER) += rawenc.oOBJS-$(CONFIG_CDG_DEMUXER) += cdg.oOBJS-$(CONFIG_CRC_MUXER) += crcenc.oOBJS-$(CONFIG_DAUD_DEMUXER) += daud.oOBJS-$(CONFIG_DAUD_MUXER) += daud.oOBJS-$(CONFIG_DFA_DEMUXER) += dfa.oOBJS-$(CONFIG_DIRAC_DEMUXER) += diracdec.o rawdec.oOBJS-$(CONFIG_DIRAC_MUXER) += rawenc.oOBJS-$(CONFIG_DNXHD_DEMUXER) += dnxhddec.o rawdec.oOBJS-$(CONFIG_DNXHD_MUXER) += rawenc.oOBJS-$(CONFIG_DSICIN_DEMUXER) += dsicin.oOBJS-$(CONFIG_DTS_DEMUXER) += dtsdec.o rawdec.oOBJS-$(CONFIG_DTS_MUXER) += rawenc.oOBJS-$(CONFIG_DV_DEMUXER) += dv.oOBJS-$(CONFIG_DV_MUXER) += dvenc.oOBJS-$(CONFIG_DXA_DEMUXER) += dxa.o riff.oOBJS-$(CONFIG_EA_CDATA_DEMUXER) += eacdata.oOBJS-$(CONFIG_EA_DEMUXER) += electronicarts.oOBJS-$(CONFIG_EAC3_DEMUXER) += ac3dec.o rawdec.oOBJS-$(CONFIG_EAC3_MUXER) += rawenc.oOBJS-$(CONFIG_FFM_DEMUXER) += ffmdec.oOBJS-$(CONFIG_FFM_MUXER) += ffmenc.oOBJS-$(CONFIG_FFMETADATA_DEMUXER) += ffmetadec.oOBJS-$(CONFIG_FFMETADATA_MUXER) += ffmetaenc.oOBJS-$(CONFIG_FILMSTRIP_DEMUXER) += filmstripdec.oOBJS-$(CONFIG_FILMSTRIP_MUXER) += filmstripenc.oOBJS-$(CONFIG_FLAC_DEMUXER) += flacdec.o rawdec.o \ oggparsevorbis.o \ vorbiscomment.oOBJS-$(CONFIG_FLAC_MUXER) += flacenc.o flacenc_header.o \ vorbiscomment.oOBJS-$(CONFIG_FLIC_DEMUXER) += flic.oOBJS-$(CONFIG_FLV_DEMUXER) += flvdec.oOBJS-$(CONFIG_FLV_MUXER) += flvenc.o avc.oOBJS-$(CONFIG_FOURXM_DEMUXER) += 4xm.oOBJS-$(CONFIG_FRAMECRC_MUXER) += framecrcenc.oOBJS-$(CONFIG_FRAMEMD5_MUXER) += md5enc.oOBJS-$(CONFIG_GIF_MUXER) += gif.oOBJS-$(CONFIG_GSM_DEMUXER) += gsmdec.oOBJS-$(CONFIG_GXF_DEMUXER) += gxf.oOBJS-$(CONFIG_GXF_MUXER) += gxfenc.o audiointerleave.oOBJS-$(CONFIG_G722_DEMUXER) += rawdec.oOBJS-$(CONFIG_G722_MUXER) += rawenc.oOBJS-$(CONFIG_G723_1_DEMUXER) += g723_1.oOBJS-$(CONFIG_G723_1_MUXER) += rawenc.oOBJS-$(CONFIG_G729_DEMUXER) += g729dec.oOBJS-$(CONFIG_H261_DEMUXER) += h261dec.o rawdec.oOBJS-$(CONFIG_H261_MUXER) += rawenc.oOBJS-$(CONFIG_H263_DEMUXER) += h263dec.o rawdec.oOBJS-$(CONFIG_H263_MUXER) += rawenc.oOBJS-$(CONFIG_H264_DEMUXER) += h264dec.o rawdec.oOBJS-$(CONFIG_H264_MUXER) += rawenc.oOBJS-$(CONFIG_ICO_DEMUXER) += icodec.oOBJS-$(CONFIG_IDCIN_DEMUXER) += idcin.oOBJS-$(CONFIG_IDF_DEMUXER) += bintext.oOBJS-$(CONFIG_IFF_DEMUXER) += iff.oOBJS-$(CONFIG_IMAGE2_DEMUXER) += img2.oOBJS-$(CONFIG_IMAGE2_MUXER) += img2.oOBJS-$(CONFIG_IMAGE2PIPE_DEMUXER) += img2.oOBJS-$(CONFIG_IMAGE2PIPE_MUXER) += img2.oOBJS-$(CONFIG_INGENIENT_DEMUXER) += ingenientdec.o rawdec.oOBJS-$(CONFIG_IPMOVIE_DEMUXER) += ipmovie.oOBJS-$(CONFIG_ISS_DEMUXER) += iss.oOBJS-$(CONFIG_IV8_DEMUXER) += iv8.oOBJS-$(CONFIG_IVF_DEMUXER) += ivfdec.o riff.oOBJS-$(CONFIG_IVF_MUXER) += ivfenc.oOBJS-$(CONFIG_JV_DEMUXER) += jvdec.oOBJS-$(CONFIG_LATM_DEMUXER) += rawdec.oOBJS-$(CONFIG_LATM_MUXER) += latmenc.oOBJS-$(CONFIG_LMLM4_DEMUXER) += lmlm4.oOBJS-$(CONFIG_LOAS_DEMUXER) += loasdec.oOBJS-$(CONFIG_LXF_DEMUXER) += lxfdec.oOBJS-$(CONFIG_M4V_DEMUXER) += m4vdec.o rawdec.oOBJS-$(CONFIG_M4V_MUXER) += rawenc.oOBJS-$(CONFIG_MATROSKA_DEMUXER) += matroskadec.o matroska.o \ riff.o isom.o rmdec.o rm.oOBJS-$(CONFIG_MATROSKA_MUXER) += matroskaenc.o matroska.o \ riff.o isom.o avc.o \ flacenc_header.o avlanguage.oOBJS-$(CONFIG_MD5_MUXER) += md5enc.oOBJS-$(CONFIG_MICRODVD_DEMUXER) += microdvddec.oOBJS-$(CONFIG_MICRODVD_MUXER) += microdvdenc.o rawenc.oOBJS-$(CONFIG_MJPEG_DEMUXER) += rawdec.oOBJS-$(CONFIG_MJPEG_MUXER) += rawenc.oOBJS-$(CONFIG_MLP_DEMUXER) += rawdec.oOBJS-$(CONFIG_MLP_MUXER) += rawenc.oOBJS-$(CONFIG_MM_DEMUXER) += mm.oOBJS-$(CONFIG_MMF_DEMUXER) += mmf.o pcm.oOBJS-$(CONFIG_MMF_MUXER) += mmf.o riff.oOBJS-$(CONFIG_MOV_DEMUXER) += mov.o riff.o isom.o mov_chan.oOBJS-$(CONFIG_MOV_MUXER) += movenc.o riff.o isom.o avc.o \ movenchint.o rtpenc_chain.o \ mov_chan.oOBJS-$(CONFIG_MP2_MUXER) += mp3enc.o rawenc.oOBJS-$(CONFIG_MP3_DEMUXER) += mp3dec.oOBJS-$(CONFIG_MP3_MUXER) += mp3enc.o rawenc.o id3v2enc.oOBJS-$(CONFIG_MPC_DEMUXER) += mpc.o apetag.oOBJS-$(CONFIG_MPC8_DEMUXER) += mpc8.oOBJS-$(CONFIG_MPEG1SYSTEM_MUXER) += mpegenc.oOBJS-$(CONFIG_MPEG1VCD_MUXER) += mpegenc.oOBJS-$(CONFIG_MPEG2DVD_MUXER) += mpegenc.oOBJS-$(CONFIG_MPEG2VOB_MUXER) += mpegenc.oOBJS-$(CONFIG_MPEG2SVCD_MUXER) += mpegenc.oOBJS-$(CONFIG_MPEG1VIDEO_MUXER) += rawenc.oOBJS-$(CONFIG_MPEG2VIDEO_MUXER) += rawenc.oOBJS-$(CONFIG_MPEGPS_DEMUXER) += mpeg.oOBJS-$(CONFIG_MPEGTS_DEMUXER) += mpegts.o isom.oOBJS-$(CONFIG_MPEGTS_MUXER) += mpegtsenc.o adtsenc.oOBJS-$(CONFIG_MPEGVIDEO_DEMUXER) += mpegvideodec.o rawdec.oOBJS-$(CONFIG_MPJPEG_MUXER) += mpjpeg.oOBJS-$(CONFIG_MSNWC_TCP_DEMUXER) += msnwc_tcp.oOBJS-$(CONFIG_MTV_DEMUXER) += mtv.oOBJS-$(CONFIG_MVI_DEMUXER) += mvi.oOBJS-$(CONFIG_MXF_DEMUXER) += mxfdec.o mxf.oOBJS-$(CONFIG_MXF_MUXER) += mxfenc.o mxf.o audiointerleave.oOBJS-$(CONFIG_MXG_DEMUXER) += mxg.oOBJS-$(CONFIG_NC_DEMUXER) += ncdec.oOBJS-$(CONFIG_NSV_DEMUXER) += nsvdec.oOBJS-$(CONFIG_NULL_MUXER) += nullenc.oOBJS-$(CONFIG_NUT_DEMUXER) += nutdec.o nut.o riff.oOBJS-$(CONFIG_NUT_MUXER) += nutenc.o nut.o riff.oOBJS-$(CONFIG_NUV_DEMUXER) += nuv.o riff.oOBJS-$(CONFIG_OGG_DEMUXER) += oggdec.o \ oggparsecelt.o \ oggparsedirac.o \ oggparseflac.o \ oggparseogm.o \ oggparseskeleton.o \ oggparsespeex.o \ oggparsetheora.o \ oggparsevorbis.o \ riff.o \ vorbiscomment.oOBJS-$(CONFIG_OGG_MUXER) += oggenc.o \ vorbiscomment.oOBJS-$(CONFIG_OMA_DEMUXER) += omadec.o pcm.o oma.oOBJS-$(CONFIG_OMA_MUXER) += omaenc.o rawenc.o oma.o id3v2enc.oOBJS-$(CONFIG_PCM_ALAW_DEMUXER) += pcmdec.o pcm.o rawdec.oOBJS-$(CONFIG_PCM_ALAW_MUXER) += pcmenc.o rawenc.oOBJS-$(CONFIG_PCM_F32BE_DEMUXER) += pcmdec.o pcm.o rawdec.oOBJS-$(CONFIG_PCM_F32BE_MUXER) += pcmenc.o rawenc.oOBJS-$(CONFIG_PCM_F32LE_DEMUXER) += pcmdec.o pcm.o rawdec.oOBJS-$(CONFIG_PCM_F32LE_MUXER) += pcmenc.o rawenc.oOBJS-$(CONFIG_PCM_F64BE_DEMUXER) += pcmdec.o pcm.o rawdec.oOBJS-$(CONFIG_PCM_F64BE_MUXER) += pcmenc.o rawenc.oOBJS-$(CONFIG_PCM_F64LE_DEMUXER) += pcmdec.o pcm.o rawdec.oOBJS-$(CONFIG_PCM_F64LE_MUXER) += pcmenc.o rawenc.oOBJS-$(CONFIG_PCM_MULAW_DEMUXER) += pcmdec.o pcm.o rawdec.oOBJS-$(CONFIG_PCM_MULAW_MUXER) += pcmenc.o rawenc.oOBJS-$(CONFIG_PCM_S16BE_DEMUXER) += pcmdec.o pcm.o rawdec.oOBJS-$(CONFIG_PCM_S16BE_MUXER) += pcmenc.o rawenc.oOBJS-$(CONFIG_PCM_S16LE_DEMUXER) += pcmdec.o pcm.o rawdec.oOBJS-$(CONFIG_PCM_S16LE_MUXER) += pcmenc.o rawenc.oOBJS-$(CONFIG_PCM_S24BE_DEMUXER) += pcmdec.o pcm.o rawdec.oOBJS-$(CONFIG_PCM_S24BE_MUXER) += pcmenc.o rawenc.oOBJS-$(CONFIG_PCM_S24LE_DEMUXER) += pcmdec.o pcm.o rawdec.oOBJS-$(CONFIG_PCM_S24LE_MUXER) += pcmenc.o rawenc.oOBJS-$(CONFIG_PCM_S32BE_DEMUXER) += pcmdec.o pcm.o rawdec.oOBJS-$(CONFIG_PCM_S32BE_MUXER) += pcmenc.o rawenc.oOBJS-$(CONFIG_PCM_S32LE_DEMUXER) += pcmdec.o pcm.o rawdec.oOBJS-$(CONFIG_PCM_S32LE_MUXER) += pcmenc.o rawenc.oOBJS-$(CONFIG_PCM_S8_DEMUXER) += pcmdec.o pcm.o rawdec.oOBJS-$(CONFIG_PCM_S8_MUXER) += pcmenc.o rawenc.oOBJS-$(CONFIG_PCM_U16BE_DEMUXER) += pcmdec.o pcm.o rawdec.oOBJS-$(CONFIG_PCM_U16BE_MUXER) += pcmenc.o rawenc.oOBJS-$(CONFIG_PCM_U16LE_DEMUXER) += pcmdec.o pcm.o rawdec.oOBJS-$(CONFIG_PCM_U16LE_MUXER) += pcmenc.o rawenc.oOBJS-$(CONFIG_PCM_U24BE_DEMUXER) += pcmdec.o pcm.o rawdec.oOBJS-$(CONFIG_PCM_U24BE_MUXER) += pcmenc.o rawenc.oOBJS-$(CONFIG_PCM_U24LE_DEMUXER) += pcmdec.o pcm.o rawdec.oOBJS-$(CONFIG_PCM_U24LE_MUXER) += pcmenc.o rawenc.oOBJS-$(CONFIG_PCM_U32BE_DEMUXER) += pcmdec.o pcm.o rawdec.oOBJS-$(CONFIG_PCM_U32BE_MUXER) += pcmenc.o rawenc.oOBJS-$(CONFIG_PCM_U32LE_DEMUXER) += pcmdec.o pcm.o rawdec.oOBJS-$(CONFIG_PCM_U32LE_MUXER) += pcmenc.o rawenc.oOBJS-$(CONFIG_PCM_U8_DEMUXER) += pcmdec.o pcm.o rawdec.oOBJS-$(CONFIG_PCM_U8_MUXER) += pcmenc.o rawenc.oOBJS-$(CONFIG_PMP_DEMUXER) += pmpdec.oOBJS-$(CONFIG_PVA_DEMUXER) += pva.oOBJS-$(CONFIG_QCP_DEMUXER) += qcp.oOBJS-$(CONFIG_R3D_DEMUXER) += r3d.oOBJS-$(CONFIG_RAWVIDEO_DEMUXER) += rawvideodec.o rawdec.oOBJS-$(CONFIG_RAWVIDEO_MUXER) += rawenc.oOBJS-$(CONFIG_RL2_DEMUXER) += rl2.oOBJS-$(CONFIG_RM_DEMUXER) += rmdec.o rm.oOBJS-$(CONFIG_RM_MUXER) += rmenc.o rm.oOBJS-$(CONFIG_ROQ_DEMUXER) += idroqdec.oOBJS-$(CONFIG_ROQ_MUXER) += idroqenc.o rawenc.oOBJS-$(CONFIG_RSO_DEMUXER) += rsodec.o rso.o pcm.oOBJS-$(CONFIG_RSO_MUXER) += rsoenc.o rso.oOBJS-$(CONFIG_RPL_DEMUXER) += rpl.oOBJS-$(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.oOBJS-$(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.oOBJS-$(CONFIG_RTSP_DEMUXER) += rtsp.o rtspdec.o httpauth.oOBJS-$(CONFIG_RTSP_MUXER) += rtsp.o rtspenc.o httpauth.o \ rtpenc_chain.oOBJS-$(CONFIG_SAP_DEMUXER) += sapdec.oOBJS-$(CONFIG_SAP_MUXER) += sapenc.o rtpenc_chain.oOBJS-$(CONFIG_SBG_DEMUXER) += sbgdec.oOBJS-$(CONFIG_SDP_DEMUXER) += rtsp.oOBJS-$(CONFIG_SEGAFILM_DEMUXER) += segafilm.oOBJS-$(CONFIG_SEGMENT_MUXER) += segment.oOBJS-$(CONFIG_SHORTEN_DEMUXER) += rawdec.oOBJS-$(CONFIG_SIFF_DEMUXER) += siff.oOBJS-$(CONFIG_SMACKER_DEMUXER) += smacker.oOBJS-$(CONFIG_SMJPEG_DEMUXER) += smjpegdec.o smjpeg.oOBJS-$(CONFIG_SMJPEG_MUXER) += smjpegenc.o smjpeg.oOBJS-$(CONFIG_SOL_DEMUXER) += sol.o pcm.oOBJS-$(CONFIG_SOX_DEMUXER) += soxdec.o pcm.oOBJS-$(CONFIG_SOX_MUXER) += soxenc.oOBJS-$(CONFIG_SPDIF_DEMUXER) += spdif.o spdifdec.oOBJS-$(CONFIG_SPDIF_MUXER) += spdif.o spdifenc.oOBJS-$(CONFIG_SRT_DEMUXER) += srtdec.oOBJS-$(CONFIG_SRT_MUXER) += rawenc.oOBJS-$(CONFIG_STR_DEMUXER) += psxstr.oOBJS-$(CONFIG_SWF_DEMUXER) += swfdec.oOBJS-$(CONFIG_SWF_MUXER) += swfenc.oOBJS-$(CONFIG_THP_DEMUXER) += thp.oOBJS-$(CONFIG_TIERTEXSEQ_DEMUXER) += tiertexseq.oOBJS-$(CONFIG_MKVTIMESTAMP_V2_MUXER) += mkvtimestamp_v2.oOBJS-$(CONFIG_TMV_DEMUXER) += tmv.oOBJS-$(CONFIG_TRUEHD_DEMUXER) += rawdec.oOBJS-$(CONFIG_TRUEHD_MUXER) += rawenc.oOBJS-$(CONFIG_TTA_DEMUXER) += tta.oOBJS-$(CONFIG_TTY_DEMUXER) += tty.o sauce.oOBJS-$(CONFIG_TXD_DEMUXER) += txd.oOBJS-$(CONFIG_VC1_DEMUXER) += rawdec.oOBJS-$(CONFIG_VC1T_DEMUXER) += vc1test.oOBJS-$(CONFIG_VC1T_MUXER) += vc1testenc.oOBJS-$(CONFIG_VMD_DEMUXER) += sierravmd.oOBJS-$(CONFIG_VOC_DEMUXER) += vocdec.o voc.oOBJS-$(CONFIG_VOC_MUXER) += vocenc.o voc.oOBJS-$(CONFIG_VQF_DEMUXER) += vqf.oOBJS-$(CONFIG_W64_DEMUXER) += wav.o riff.o pcm.oOBJS-$(CONFIG_WAV_DEMUXER) += wav.o riff.o pcm.oOBJS-$(CONFIG_WAV_MUXER) += wav.o riff.oOBJS-$(CONFIG_WC3_DEMUXER) += wc3movie.oOBJS-$(CONFIG_WEBM_MUXER) += matroskaenc.o matroska.o \ riff.o isom.o avc.o \ flacenc_header.o avlanguage.oOBJS-$(CONFIG_WSAUD_DEMUXER) += westwood_aud.oOBJS-$(CONFIG_WSVQA_DEMUXER) += westwood_vqa.oOBJS-$(CONFIG_WTV_DEMUXER) += wtvdec.o wtv.o asfdec.o asf.o asfcrypt.o \ avlanguage.o mpegts.o isom.o riff.oOBJS-$(CONFIG_WTV_MUXER) += wtvenc.o wtv.o asf.o asfenc.o riff.oOBJS-$(CONFIG_WV_DEMUXER) += wv.o apetag.oOBJS-$(CONFIG_XA_DEMUXER) += xa.oOBJS-$(CONFIG_XBIN_DEMUXER) += bintext.o sauce.oOBJS-$(CONFIG_XMV_DEMUXER) += xmv.o riff.oOBJS-$(CONFIG_XWMA_DEMUXER) += xwma.o riff.oOBJS-$(CONFIG_YOP_DEMUXER) += yop.oOBJS-$(CONFIG_YUV4MPEGPIPE_MUXER) += yuv4mpeg.oOBJS-$(CONFIG_YUV4MPEGPIPE_DEMUXER) += yuv4mpeg.o# external librariesOBJS-$(CONFIG_LIBMODPLUG_DEMUXER) += libmodplug.oOBJS-$(CONFIG_LIBNUT_DEMUXER) += libnut.o riff.oOBJS-$(CONFIG_LIBNUT_MUXER) += libnut.o riff.o# protocols I/OOBJS+= avio.o aviobuf.oOBJS-$(CONFIG_APPLEHTTP_PROTOCOL) += applehttpproto.oOBJS-$(CONFIG_CACHE_PROTOCOL) += cache.oOBJS-$(CONFIG_CONCAT_PROTOCOL) += concat.oOBJS-$(CONFIG_CRYPTO_PROTOCOL) += crypto.oOBJS-$(CONFIG_FILE_PROTOCOL) += file.oOBJS-$(CONFIG_GOPHER_PROTOCOL) += gopher.oOBJS-$(CONFIG_HTTP_PROTOCOL) += http.o httpauth.oOBJS-$(CONFIG_HTTPPROXY_PROTOCOL) += http.o httpauth.oOBJS-$(CONFIG_HTTPS_PROTOCOL) += http.o httpauth.oOBJS-$(CONFIG_MMSH_PROTOCOL) += mmsh.o mms.o asf.oOBJS-$(CONFIG_MMST_PROTOCOL) += mmst.o mms.o asf.oOBJS-$(CONFIG_MD5_PROTOCOL) += md5proto.oOBJS-$(CONFIG_PIPE_PROTOCOL) += file.o# external or internal rtmpRTMP-OBJS-$(CONFIG_LIBRTMP) = librtmp.oRTMP-OBJS-$(!CONFIG_LIBRTMP) = rtmpproto.o rtmppkt.oOBJS-$(CONFIG_RTMP_PROTOCOL) += $(RTMP-OBJS-yes)OBJS-$(CONFIG_RTP_PROTOCOL) += rtpproto.oOBJS-$(CONFIG_TCP_PROTOCOL) += tcp.oOBJS-$(CONFIG_TLS_PROTOCOL) += tls.oOBJS-$(CONFIG_UDP_PROTOCOL) += udp.oSKIPHEADERS-$(CONFIG_NETWORK) += network.h rtsp.hTESTPROGS = seekTOOLS = 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# leixiaohua1020@126.com# 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=53LIBVERSION := $(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)-staticinstall-libs-$(CONFIG_SHARED): install-lib$(NAME)-shareddefine 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,$$^) $(FFEXTRALIBS) $(EXTRAOBJS)$(SLIB_EXTRA_CMD)#SLIBNAME_WITH_MAJOR包含了Major版本号。例如：libavformat-53.dllifdef SUBDIR$(SUBDIR)$(SLIBNAME_WITH_MAJOR): $(DEP_LIBS)endif#清空clean::$(RM) $(addprefix $(SUBDIR),*-example$(EXESUF) *-test$(EXESUF) $(CLEANFILES) $(CLEANSUFFIXES) $(LIBSUFFIXES)) \ $(foreach dir,$(DIRS),$(CLEANSUFFIXES:%=$(SUBDIR)$(dir)/%)) \ $(HOSTOBJS) $(HOSTPROGS)distclean:: clean$(RM) $(DISTCLEANSUFFIXES:%=$(SUBDIR)%) \ $(foreach dir,$(DIRS),$(DISTCLEANSUFFIXES:%=$(SUBDIR)$(dir)/%))#安装库文件=====================install-lib$(NAME)-shared: $(SUBDIR)$(SLIBNAME)$(Q)mkdir -p "$(SHLIBDIR)"$$(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()#$(addprefix src/,foo bar)返回值是“src/foo src/bar”。#【HEADERS来自于每个类库的Makefile】#例如libavformat中HEADERS = avformat.h avio.h version.hinstall-lib$(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# leixiaohua1020@126.com# 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 targetall: all-yesifndef SUBDIR#在控制台打印信息ifndef VQ = @#输出ECHO = printf "$(1)\t%s\n" $(2)BRIEF = CC CXX AS YASM AR LD HOSTCC STRIP CPSILENT = DEPCC YASMDEP RM RANLIBMSG = $@M = @$(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libALLFFLIBS = 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.asmHOSTCFLAGS += $(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:libavutilLDFLAGS := $(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_MACROSdefine 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):endifOBJS-$(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): | toolsOBJDIRS := $(OBJDIRS) $(dir $(OBJS) $(HOSTOBJS) $(TESTOBJS))CLEANSUFFIXES = *.d *.o *~ *.ho *.map *.ver *.gcno *.gcdaDISTCLEANSUFFIXES = *.pcLIBSUFFIXES = *.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
leixiaohua1020@126.com
http://blog.csdn.net/leixiaohua1020
6 0
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- 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 ： av_register_all()
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- 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 ： av_register_all()
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- 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 ： av_register_all()
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