FFmpeg 中./configure的解析
本文以ffmpeg-5.1.6中的./configure为蓝本进行编译过程的解析。
接上文“Android Liunx ffmpeg交叉编译”中的android_build1.sh的脚本执行过程来分析。
一、ffmpeg-5.1.6中的./configure：
1、定位./configure脚本：
进入ffmpeg文件夹中，可以找到./configure脚本文件。现在在此文件目录下只执行./configure脚本会发生什么。
./configure 2、执行./configure：
执行./configure打印出如的log：
3、在./configure脚本log代码定位：
./configure脚本代码中的7474行，开启了终端的log的打印，对应上图的终端打印的显示结果。
4、./configure脚本log打印代码：
当quite设置不为yes时会执行如下代码：
if test "$quiet" != "yes"; thenecho "install prefix $prefix"
echo "source path $source_path"
echo "C compiler $cc"
echo "C library $libc_type"
if test "$host_cc" != "$cc"; thenecho "host C compiler $host_cc"echo "host C library $host_libc_type"
fi
echo "ARCH $arch ($cpu)"
if test "$build_suffix" != ""; thenecho "build suffix $build_suffix"
fi
if test "$progs_suffix" != ""; thenecho "progs suffix $progs_suffix"
fi
if test "$extra_version" != ""; thenecho "version string suffix $extra_version"
fi
echo "big-endian ${bigendian-no}"
echo "runtime cpu detection ${runtime_cpudetect-no}"
if enabled x86; thenecho "standalone assembly ${x86asm-no}"echo "x86 assembler ${x86asmexe}"echo "MMX enabled ${mmx-no}"echo "MMXEXT enabled ${mmxext-no}"echo "3DNow! enabled ${amd3dnow-no}"echo "3DNow! extended enabled ${amd3dnowext-no}"echo "SSE enabled ${sse-no}"echo "SSSE3 enabled ${ssse3-no}"echo "AESNI enabled ${aesni-no}"echo "AVX enabled ${avx-no}"echo "AVX2 enabled ${avx2-no}"echo "AVX-512 enabled ${avx512-no}"echo "AVX-512ICL enabled ${avx512icl-no}"echo "XOP enabled ${xop-no}"echo "FMA3 enabled ${fma3-no}"echo "FMA4 enabled ${fma4-no}"echo "i686 features enabled ${i686-no}"echo "CMOV is fast ${fast_cmov-no}"echo "EBX available ${ebx_available-no}"echo "EBP available ${ebp_available-no}"
fi
if enabled aarch64; thenecho "NEON enabled ${neon-no}"echo "VFP enabled ${vfp-no}"
fi
if enabled arm; thenecho "ARMv5TE enabled ${armv5te-no}"echo "ARMv6 enabled ${armv6-no}"echo "ARMv6T2 enabled ${armv6t2-no}"echo "VFP enabled ${vfp-no}"echo "NEON enabled ${neon-no}"echo "THUMB enabled ${thumb-no}"
fi
if enabled mips; thenecho "MIPS FPU enabled ${mipsfpu-no}"echo "MIPS DSP R1 enabled ${mipsdsp-no}"echo "MIPS DSP R2 enabled ${mipsdspr2-no}"echo "MIPS MSA enabled ${msa-no}"echo "LOONGSON MMI enabled ${mmi-no}"
fi
if enabled ppc; thenecho "AltiVec enabled ${altivec-no}"echo "VSX enabled ${vsx-no}"echo "POWER8 enabled ${power8-no}"echo "PPC 4xx optimizations ${ppc4xx-no}"echo "dcbzl available ${dcbzl-no}"
fi
if enabled loongarch; thenecho "LSX enabled ${lsx-no}"echo "LASX enabled ${lasx-no}"
fi
echo "debug symbols ${debug-no}"
echo "strip symbols ${stripping-no}"
echo "optimize for size ${small-no}"
echo "optimizations ${optimizations-no}"
echo "static ${static-no}"
echo "shared ${shared-no}"
echo "postprocessing support ${postproc-no}"
echo "network support ${network-no}"
echo "threading support ${thread_type-no}"
echo "safe bitstream reader ${safe_bitstream_reader-no}"
echo "texi2html enabled ${texi2html-no}"
echo "perl enabled ${perl-no}"
echo "pod2man enabled ${pod2man-no}"
echo "makeinfo enabled ${makeinfo-no}"
echo "makeinfo supports HTML ${makeinfo_html-no}"
echo "xmllint enabled ${xmllint-no}"
test -n "$random_seed" &&echo "random seed ${random_seed}"
echoecho "External libraries:"
print_enabled '' $EXTERNAL_LIBRARY_LIST $EXTERNAL_AUTODETECT_LIBRARY_LIST | print_in_columns
echoecho "External libraries providing hardware acceleration:"
print_enabled '' $HWACCEL_LIBRARY_LIST $HWACCEL_AUTODETECT_LIBRARY_LIST | print_in_columns
echoecho "Libraries:"
print_enabled '' $LIBRARY_LIST | print_in_columns
echoecho "Programs:"
print_enabled '' $PROGRAM_LIST | print_in_columns
echofor type in decoder encoder hwaccel parser demuxer muxer protocol filter bsf indev outdev; doecho "Enabled ${type}s:"eval list=\$$(toupper $type)_LISTprint_enabled '_*' $list | print_in_columnsecho
doneif test -n "$ignore_tests"; thenignore_tests=$(echo $ignore_tests | tr ',' ' ')echo "Ignored FATE tests:"echo $ignore_tests | print_in_columnsecho
fiecho "License: $license"fi # test "$quiet" != "yes"5、./configure中Options设置选项：
执行./configure --help会打印出所有的Option可设置的选项如下图：
6、在./configure脚本Options代码定位：
./configure脚本源码Options的开始行为59行，如下图显示：
这些设置的选择就是android_build1.sh中编译设置的来源，可根据的编译的需求进行可选编译设置。
show_help(){cat <<EOF
Usage: configure [options]
Options: [defaults in brackets after descriptions]Help options:--help print this message--quiet Suppress showing informative output--list-decoders show all available decoders--list-encoders show all available encoders--list-hwaccels show all available hardware accelerators--list-demuxers show all available demuxers--list-muxers show all available muxers--list-parsers show all available parsers--list-protocols show all available protocols--list-bsfs show all available bitstream filters--list-indevs show all available input devices--list-outdevs show all available output devices--list-filters show all available filtersStandard options:--logfile=FILE log tests and output to FILE [ffbuild/config.log]--disable-logging do not log configure debug information--fatal-warnings fail if any configure warning is generated--prefix=PREFIX install in PREFIX [$prefix_default]--bindir=DIR install binaries in DIR [PREFIX/bin]--datadir=DIR install data files in DIR [PREFIX/share/ffmpeg]--docdir=DIR install documentation in DIR [PREFIX/share/doc/ffmpeg]--libdir=DIR install libs in DIR [PREFIX/lib]--shlibdir=DIR install shared libs in DIR [LIBDIR]--incdir=DIR install includes in DIR [PREFIX/include]--mandir=DIR install man page in DIR [PREFIX/share/man]--pkgconfigdir=DIR install pkg-config files in DIR [LIBDIR/pkgconfig]--enable-rpath use rpath to allow installing libraries in pathsnot part of the dynamic linker search pathuse rpath when linking programs (USE WITH CARE)--install-name-dir=DIR Darwin directory name for installed targetsLicensing options:--enable-gpl allow use of GPL code, the resulting libsand binaries will be under GPL [no]--enable-version3 upgrade (L)GPL to version 3 [no]--enable-nonfree allow use of nonfree code, the resulting libsand binaries will be unredistributable [no]Configuration options:--disable-static do not build static libraries [no]--enable-shared build shared libraries [no]--enable-small optimize for size instead of speed--disable-runtime-cpudetect disable detecting CPU capabilities at runtime (smaller binary)--enable-gray enable full grayscale support (slower color)--disable-swscale-alpha disable alpha channel support in swscale--disable-all disable building components, libraries and programs--disable-autodetect disable automatically detected external libraries [no]Program options:--disable-programs do not build command line programs--disable-ffmpeg disable ffmpeg build--disable-ffplay disable ffplay build--disable-ffprobe disable ffprobe buildDocumentation options:--disable-doc do not build documentation--disable-htmlpages do not build HTML documentation pages--disable-manpages do not build man documentation pages--disable-podpages do not build POD documentation pages--disable-txtpages do not build text documentation pagesComponent options:--disable-avdevice disable libavdevice build--disable-avcodec disable libavcodec build--disable-avformat disable libavformat build--disable-swresample disable libswresample build--disable-swscale disable libswscale build--disable-postproc disable libpostproc build--disable-avfilter disable libavfilter build--disable-pthreads disable pthreads [autodetect]--disable-w32threads disable Win32 threads [autodetect]--disable-os2threads disable OS/2 threads [autodetect]--disable-network disable network support [no]--disable-dct disable DCT code--disable-dwt disable DWT code--disable-error-resilience disable error resilience code--disable-lsp disable LSP code--disable-mdct disable MDCT code--disable-rdft disable RDFT code--disable-fft disable FFT code--disable-faan disable floating point AAN (I)DCT code--disable-pixelutils disable pixel utils in libavutilIndividual component options:--disable-everything disable all components listed below--disable-encoder=NAME disable encoder NAME--enable-encoder=NAME enable encoder NAME--disable-encoders disable all encoders--disable-decoder=NAME disable decoder NAME--enable-decoder=NAME enable decoder NAME--disable-decoders disable all decoders--disable-hwaccel=NAME disable hwaccel NAME--enable-hwaccel=NAME enable hwaccel NAME--disable-hwaccels disable all hwaccels--disable-muxer=NAME disable muxer NAME--enable-muxer=NAME enable muxer NAME--disable-muxers disable all muxers--disable-demuxer=NAME disable demuxer NAME--enable-demuxer=NAME enable demuxer NAME--disable-demuxers disable all demuxers--enable-parser=NAME enable parser NAME--disable-parser=NAME disable parser NAME--disable-parsers disable all parsers--enable-bsf=NAME enable bitstream filter NAME--disable-bsf=NAME disable bitstream filter NAME--disable-bsfs disable all bitstream filters--enable-protocol=NAME enable protocol NAME--disable-protocol=NAME disable protocol NAME--disable-protocols disable all protocols--enable-indev=NAME enable input device NAME--disable-indev=NAME disable input device NAME--disable-indevs disable input devices--enable-outdev=NAME enable output device NAME--disable-outdev=NAME disable output device NAME--disable-outdevs disable output devices--disable-devices disable all devices--enable-filter=NAME enable filter NAME--disable-filter=NAME disable filter NAME--disable-filters disable all filtersExternal library support:Using any of the following switches will allow FFmpeg to link to thecorresponding external library. All the components depending on that librarywill become enabled, if all their other dependencies are met and they are notexplicitly disabled. E.g. --enable-libopus will enable linking tolibopus and allow the libopus encoder to be built, unless it isspecifically disabled with --disable-encoder=libopus.Note that only the system libraries are auto-detected. All the other externallibraries must be explicitly enabled.Also note that the following help text describes the purpose of the librariesthemselves, not all their features will necessarily be usable by FFmpeg.--disable-alsa disable ALSA support [autodetect]--disable-appkit disable Apple AppKit framework [autodetect]--disable-avfoundation disable Apple AVFoundation framework [autodetect]--enable-avisynth enable reading of AviSynth script files [no]--disable-bzlib disable bzlib [autodetect]--disable-coreimage disable Apple CoreImage framework [autodetect]--enable-chromaprint enable audio fingerprinting with chromaprint [no]--enable-frei0r enable frei0r video filtering [no]--enable-gcrypt enable gcrypt, needed for rtmp(t)e supportif openssl, librtmp or gmp is not used [no]--enable-gmp enable gmp, needed for rtmp(t)e supportif openssl or librtmp is not used [no]--enable-gnutls enable gnutls, needed for https supportif openssl, libtls or mbedtls is not used [no]--disable-iconv disable iconv [autodetect]--enable-jni enable JNI support [no]--enable-ladspa enable LADSPA audio filtering [no]--enable-lcms2 enable ICC profile support via LittleCMS 2 [no]--enable-libaom enable AV1 video encoding/decoding via libaom [no]--enable-libaribb24 enable ARIB text and caption decoding via libaribb24 [no]--enable-libass enable libass subtitles rendering,needed for subtitles and ass filter [no]--enable-libbluray enable BluRay reading using libbluray [no]--enable-libbs2b enable bs2b DSP library [no]--enable-libcaca enable textual display using libcaca [no]--enable-libcelt enable CELT decoding via libcelt [no]--enable-libcdio enable audio CD grabbing with libcdio [no]--enable-libcodec2 enable codec2 en/decoding using libcodec2 [no]--enable-libdav1d enable AV1 decoding via libdav1d [no]--enable-libdavs2 enable AVS2 decoding via libdavs2 [no]--enable-libdc1394 enable IIDC-1394 grabbing using libdc1394and libraw1394 [no]--enable-libfdk-aac enable AAC de/encoding via libfdk-aac [no]--enable-libflite enable flite (voice synthesis) support via libflite [no]--enable-libfontconfig enable libfontconfig, useful for drawtext filter [no]--enable-libfreetype enable libfreetype, needed for drawtext filter [no]--enable-libfribidi enable libfribidi, improves drawtext filter [no]--enable-libglslang enable GLSL->SPIRV compilation via libglslang [no]--enable-libgme enable Game Music Emu via libgme [no]--enable-libgsm enable GSM de/encoding via libgsm [no]--enable-libiec61883 enable iec61883 via libiec61883 [no]--enable-libilbc enable iLBC de/encoding via libilbc [no]--enable-libjack enable JACK audio sound server [no]--enable-libjxl enable JPEG XL de/encoding via libjxl [no]--enable-libklvanc enable Kernel Labs VANC processing [no]--enable-libkvazaar enable HEVC encoding via libkvazaar [no]--enable-liblensfun enable lensfun lens correction [no]--enable-libmodplug enable ModPlug via libmodplug [no]--enable-libmp3lame enable MP3 encoding via libmp3lame [no]--enable-libopencore-amrnb enable AMR-NB de/encoding via libopencore-amrnb [no]--enable-libopencore-amrwb enable AMR-WB decoding via libopencore-amrwb [no]--enable-libopencv enable video filtering via libopencv [no]--enable-libopenh264 enable H.264 encoding via OpenH264 [no]--enable-libopenjpeg enable JPEG 2000 de/encoding via OpenJPEG [no]--enable-libopenmpt enable decoding tracked files via libopenmpt [no]--enable-libopenvino enable OpenVINO as a DNN module backendfor DNN based filters like dnn_processing [no]--enable-libopus enable Opus de/encoding via libopus [no]--enable-libplacebo enable libplacebo library [no]--enable-libpulse enable Pulseaudio input via libpulse [no]--enable-librabbitmq enable RabbitMQ library [no]--enable-librav1e enable AV1 encoding via rav1e [no]--enable-librist enable RIST via librist [no]--enable-librsvg enable SVG rasterization via librsvg [no]--enable-librubberband enable rubberband needed for rubberband filter [no]--enable-librtmp enable RTMP[E] support via librtmp [no]--enable-libshaderc enable GLSL->SPIRV compilation via libshaderc [no]--enable-libshine enable fixed-point MP3 encoding via libshine [no]--enable-libsmbclient enable Samba protocol via libsmbclient [no]--enable-libsnappy enable Snappy compression, needed for hap encoding [no]--enable-libsoxr enable Include libsoxr resampling [no]--enable-libspeex enable Speex de/encoding via libspeex [no]--enable-libsrt enable Haivision SRT protocol via libsrt [no]--enable-libssh enable SFTP protocol via libssh [no]--enable-libsvtav1 enable AV1 encoding via SVT [no]--enable-libtensorflow enable TensorFlow as a DNN module backendfor DNN based filters like sr [no]--enable-libtesseract enable Tesseract, needed for ocr filter [no]--enable-libtheora enable Theora encoding via libtheora [no]--enable-libtls enable LibreSSL (via libtls), needed for https supportif openssl, gnutls or mbedtls is not used [no]--enable-libtwolame enable MP2 encoding via libtwolame [no]--enable-libuavs3d enable AVS3 decoding via libuavs3d [no]--enable-libv4l2 enable libv4l2/v4l-utils [no]--enable-libvidstab enable video stabilization using vid.stab [no]--enable-libvmaf enable vmaf filter via libvmaf [no]--enable-libvo-amrwbenc enable AMR-WB encoding via libvo-amrwbenc [no]--enable-libvorbis enable Vorbis en/decoding via libvorbis,native implementation exists [no]--enable-libvpx enable VP8 and VP9 de/encoding via libvpx [no]--enable-libwebp enable WebP encoding via libwebp [no]--enable-libx264 enable H.264 encoding via x264 [no]--enable-libx265 enable HEVC encoding via x265 [no]--enable-libxavs enable AVS encoding via xavs [no]--enable-libxavs2 enable AVS2 encoding via xavs2 [no]--enable-libxcb enable X11 grabbing using XCB [autodetect]--enable-libxcb-shm enable X11 grabbing shm communication [autodetect]--enable-libxcb-xfixes enable X11 grabbing mouse rendering [autodetect]--enable-libxcb-shape enable X11 grabbing shape rendering [autodetect]--enable-libxvid enable Xvid encoding via xvidcore,native MPEG-4/Xvid encoder exists [no]--enable-libxml2 enable XML parsing using the C library libxml2, neededfor dash and imf demuxing support [no]--enable-libzimg enable z.lib, needed for zscale filter [no]--enable-libzmq enable message passing via libzmq [no]--enable-libzvbi enable teletext support via libzvbi [no]--enable-lv2 enable LV2 audio filtering [no]--disable-lzma disable lzma [autodetect]--enable-decklink enable Blackmagic DeckLink I/O support [no]--enable-mbedtls enable mbedTLS, needed for https supportif openssl, gnutls or libtls is not used [no]--enable-mediacodec enable Android MediaCodec support [no]--enable-mediafoundation enable encoding via MediaFoundation [auto]--disable-metal disable Apple Metal framework [autodetect]--enable-libmysofa enable libmysofa, needed for sofalizer filter [no]--enable-openal enable OpenAL 1.1 capture support [no]--enable-opencl enable OpenCL processing [no]--enable-opengl enable OpenGL rendering [no]--enable-openssl enable openssl, needed for https supportif gnutls, libtls or mbedtls is not used [no]--enable-pocketsphinx enable PocketSphinx, needed for asr filter [no]--disable-sndio disable sndio support [autodetect]--disable-schannel disable SChannel SSP, needed for TLS support onWindows if openssl and gnutls are not used [autodetect]--disable-sdl2 disable sdl2 [autodetect]--disable-securetransport disable Secure Transport, needed for TLS supporton OSX if openssl and gnutls are not used [autodetect]--enable-vapoursynth enable VapourSynth demuxer [no]--disable-vulkan disable Vulkan code [autodetect]--disable-xlib disable xlib [autodetect]--disable-zlib disable zlib [autodetect]The following libraries provide various hardware acceleration features:--disable-amf disable AMF video encoding code [autodetect]--disable-audiotoolbox disable Apple AudioToolbox code [autodetect]--enable-cuda-nvcc enable Nvidia CUDA compiler [no]--disable-cuda-llvm disable CUDA compilation using clang [autodetect]--disable-cuvid disable Nvidia CUVID support [autodetect]--disable-d3d11va disable Microsoft Direct3D 11 video acceleration code [autodetect]--disable-dxva2 disable Microsoft DirectX 9 video acceleration code [autodetect]--disable-ffnvcodec disable dynamically linked Nvidia code [autodetect]--enable-libdrm enable DRM code (Linux) [no]--enable-libmfx enable Intel MediaSDK (AKA Quick Sync Video) code via libmfx [no]--enable-libnpp enable Nvidia Performance Primitives-based code [no]--enable-mmal enable Broadcom Multi-Media Abstraction Layer (Raspberry Pi) via MMAL [no]--disable-nvdec disable Nvidia video decoding acceleration (via hwaccel) [autodetect]--disable-nvenc disable Nvidia video encoding code [autodetect]--enable-omx enable OpenMAX IL code [no]--enable-omx-rpi enable OpenMAX IL code for Raspberry Pi [no]--enable-rkmpp enable Rockchip Media Process Platform code [no]--disable-v4l2-m2m disable V4L2 mem2mem code [autodetect]--disable-vaapi disable Video Acceleration API (mainly Unix/Intel) code [autodetect]--disable-vdpau disable Nvidia Video Decode and Presentation API for Unix code [autodetect]--disable-videotoolbox disable VideoToolbox code [autodetect]Toolchain options:--arch=ARCH select architecture [$arch]--cpu=CPU select the minimum required CPU (affectsinstruction selection, may crash on older CPUs)--cross-prefix=PREFIX use PREFIX for compilation tools [$cross_prefix]--progs-suffix=SUFFIX program name suffix []--enable-cross-compile assume a cross-compiler is used--sysroot=PATH root of cross-build tree--sysinclude=PATH location of cross-build system headers--target-os=OS compiler targets OS [$target_os]--target-exec=CMD command to run executables on target--target-path=DIR path to view of build directory on target--target-samples=DIR path to samples directory on target--tempprefix=PATH force fixed dir/prefix instead of mktemp for checks--toolchain=NAME set tool defaults according to NAME(gcc-asan, clang-asan, gcc-msan, clang-msan,gcc-tsan, clang-tsan, gcc-usan, clang-usan,valgrind-massif, valgrind-memcheck,msvc, icl, gcov, llvm-cov, hardened)--nm=NM use nm tool NM [$nm_default]--ar=AR use archive tool AR [$ar_default]--as=AS use assembler AS [$as_default]--ln_s=LN_S use symbolic link tool LN_S [$ln_s_default]--strip=STRIP use strip tool STRIP [$strip_default]--windres=WINDRES use windows resource compiler WINDRES [$windres_default]--x86asmexe=EXE use nasm-compatible assembler EXE [$x86asmexe_default]--cc=CC use C compiler CC [$cc_default]--cxx=CXX use C compiler CXX [$cxx_default]--objcc=OCC use ObjC compiler OCC [$cc_default]--dep-cc=DEPCC use dependency generator DEPCC [$cc_default]--nvcc=NVCC use Nvidia CUDA compiler NVCC or clang [$nvcc_default]--ld=LD use linker LD [$ld_default]--metalcc=METALCC use metal compiler METALCC [$metalcc_default]--metallib=METALLIB use metal linker METALLIB [$metallib_default]--pkg-config=PKGCONFIG use pkg-config tool PKGCONFIG [$pkg_config_default]--pkg-config-flags=FLAGS pass additional flags to pkgconf []--ranlib=RANLIB use ranlib RANLIB [$ranlib_default]--doxygen=DOXYGEN use DOXYGEN to generate API doc [$doxygen_default]--host-cc=HOSTCC use host C compiler HOSTCC--host-cflags=HCFLAGS use HCFLAGS when compiling for host--host-cppflags=HCPPFLAGS use HCPPFLAGS when compiling for host--host-ld=HOSTLD use host linker HOSTLD--host-ldflags=HLDFLAGS use HLDFLAGS when linking for host--host-extralibs=HLIBS use libs HLIBS when linking for host--host-os=OS compiler host OS [$target_os]--extra-cflags=ECFLAGS add ECFLAGS to CFLAGS [$CFLAGS]--extra-cxxflags=ECFLAGS add ECFLAGS to CXXFLAGS [$CXXFLAGS]--extra-objcflags=FLAGS add FLAGS to OBJCFLAGS [$CFLAGS]--extra-ldflags=ELDFLAGS add ELDFLAGS to LDFLAGS [$LDFLAGS]--extra-ldexeflags=ELDFLAGS add ELDFLAGS to LDEXEFLAGS [$LDEXEFLAGS]--extra-ldsoflags=ELDFLAGS add ELDFLAGS to LDSOFLAGS [$LDSOFLAGS]--extra-libs=ELIBS add ELIBS [$ELIBS]--extra-version=STRING version string suffix []--optflags=OPTFLAGS override optimization-related compiler flags--nvccflags=NVCCFLAGS override nvcc flags [$nvccflags_default]--build-suffix=SUFFIX library name suffix []--enable-pic build position-independent code--enable-thumb compile for Thumb instruction set--enable-lto use link-time optimization--env="ENV=override" override the environment variablesAdvanced options (experts only):--malloc-prefix=PREFIX prefix malloc and related names with PREFIX--custom-allocator=NAME use a supported custom allocator--disable-symver disable symbol versioning--enable-hardcoded-tables use hardcoded tables instead of runtime generation--disable-safe-bitstream-readerdisable buffer boundary checking in bitreaders(faster, but may crash)--sws-max-filter-size=N the max filter size swscale uses [$sws_max_filter_size_default]Optimization options (experts only):--disable-asm disable all assembly optimizations--disable-altivec disable AltiVec optimizations--disable-vsx disable VSX optimizations--disable-power8 disable POWER8 optimizations--disable-amd3dnow disable 3DNow! optimizations--disable-amd3dnowext disable 3DNow! extended optimizations--disable-mmx disable MMX optimizations--disable-mmxext disable MMXEXT optimizations--disable-sse disable SSE optimizations--disable-sse2 disable SSE2 optimizations--disable-sse3 disable SSE3 optimizations--disable-ssse3 disable SSSE3 optimizations--disable-sse4 disable SSE4 optimizations--disable-sse42 disable SSE4.2 optimizations--disable-avx disable AVX optimizations--disable-xop disable XOP optimizations--disable-fma3 disable FMA3 optimizations--disable-fma4 disable FMA4 optimizations--disable-avx2 disable AVX2 optimizations--disable-avx512 disable AVX-512 optimizations--disable-avx512icl disable AVX-512ICL optimizations--disable-aesni disable AESNI optimizations--disable-armv5te disable armv5te optimizations--disable-armv6 disable armv6 optimizations--disable-armv6t2 disable armv6t2 optimizations--disable-vfp disable VFP optimizations--disable-neon disable NEON optimizations--disable-inline-asm disable use of inline assembly--disable-x86asm disable use of standalone x86 assembly--disable-mipsdsp disable MIPS DSP ASE R1 optimizations--disable-mipsdspr2 disable MIPS DSP ASE R2 optimizations--disable-msa disable MSA optimizations--disable-mipsfpu disable floating point MIPS optimizations--disable-mmi disable Loongson MMI optimizations--disable-lsx disable Loongson LSX optimizations--disable-lasx disable Loongson LASX optimizations--disable-fast-unaligned consider unaligned accesses slowDeveloper options (useful when working on FFmpeg itself):--disable-debug disable debugging symbols--enable-debug=LEVEL set the debug level [$debuglevel]--disable-optimizations disable compiler optimizations--enable-extra-warnings enable more compiler warnings--disable-stripping disable stripping of executables and shared libraries--assert-level=level 0(default), 1 or 2, amount of assertion testing,2 causes a slowdown at runtime.--enable-memory-poisoning fill heap uninitialized allocated space with arbitrary data--valgrind=VALGRIND run "make fate" tests through valgrind to detect memoryleaks and errors, using the specified valgrind binary.Cannot be combined with --target-exec--enable-ftrapv Trap arithmetic overflows--samples=PATH location of test samples for FATE, if not set use\$FATE_SAMPLES at make invocation time.--enable-neon-clobber-test check NEON registers for clobbering (should beused only for debugging purposes)--enable-xmm-clobber-test check XMM registers for clobbering (Win64-only;should be used only for debugging purposes)--enable-random randomly enable/disable components--disable-random--enable-random=LIST randomly enable/disable specific components or--disable-random=LIST component groups. LIST is a comma-separated listof NAME[:PROB] entries where NAME is a component(group) and PROB the probability associated withNAME (default 0.5).--random-seed=VALUE seed value for --enable/disable-random--disable-valgrind-backtrace do not print a backtrace under Valgrind(only applies to --disable-optimizations builds)--enable-ossfuzz Enable building fuzzer tool--libfuzzer=PATH path to libfuzzer--ignore-tests=TESTS comma-separated list (without "fate-" prefixin the name) of tests whose result is ignored--enable-linux-perf enable Linux Performance Monitor API--enable-macos-kperf enable macOS kperf (private) API--disable-large-tests disable tests that use a large amount of memory--disable-ptx-compression don't compress CUDA PTX code even when possibleNOTE: Object files are built at the place where configure is launched.
EOFexit 0
}
二、android_build1.sh分析：
执行流程如下：
1、build all（方法入口）——> 2、拼接./configure的Option参数（如：“--disable-static”不编译静态库）——> 3、build函数（如：build "arm64-v8a"，传入"arm64-v8a"参数到函数build()）——> 4、build()根据不同平台遍历出对应的所需的交叉工具链，设置到./configure的Option参数中 ——> 5、执行./configure ${CONFIGURATION} ——> 6、make -j 及make install开始make操作。
代码如下：
#!/bin/bash
# 用于编译android平台的脚本# NDK所在目录
NDK_PATH=/home/wyy/Android/NDKS/android-ndk-r27c # tag1
# macOS 平台编译，其他平台看一下 $NDK_PATH/toolchains/llvm/prebuilt/ 下的文件夹名称
HOST_PLATFORM=linux-x86_64 #tag1
# minSdkVersion
API=23TOOLCHAINS="$NDK_PATH/toolchains/llvm/prebuilt/$HOST_PLATFORM"
SYSROOT="$NDK_PATH/toolchains/llvm/prebuilt/$HOST_PLATFORM/sysroot"
# 生成 -fpic 与位置无关的代码
CFLAG="-D__ANDROID_API__=$API -Os -fPIC -DANDROID "
LDFLAG="-lc -lm -ldl -llog "# 输出目录
PREFIX=`pwd`/android
# 日志输出目录
CONFIG_LOG_PATH=${PREFIX}/log
# 公共配置
COMMON_OPTIONS=
# 交叉配置
CONFIGURATION=build() {APP_ABI=$1echo "======== > Start build $APP_ABI"case ${APP_ABI} inarmeabi-v7a)ARCH="arm"CPU="armv7-a"MARCH="armv7-a"TARGET=armv7a-linux-androideabiCC="$TOOLCHAINS/bin/$TARGET$API-clang"CXX="$TOOLCHAINS/bin/$TARGET$API-clang++"LD="$TOOLCHAINS/bin/$TARGET$API-clang"# 交叉编译工具前缀CROSS_PREFIX="$TOOLCHAINS/bin/arm-linux-androideabi-"EXTRA_CFLAGS="$CFLAG -mfloat-abi=softfp -mfpu=vfp -marm -march=$MARCH "EXTRA_LDFLAGS="$LDFLAG"EXTRA_OPTIONS="--enable-neon --cpu=$CPU ";;arm64-v8a)ARCH="aarch64"TARGET=$ARCH-linux-androidCC="$TOOLCHAINS/bin/$TARGET$API-clang"CXX="$TOOLCHAINS/bin/$TARGET$API-clang++"LD="$TOOLCHAINS/bin/$TARGET$API-clang"CROSS_PREFIX="$TOOLCHAINS/bin/$TARGET-"EXTRA_CFLAGS="$CFLAG"EXTRA_LDFLAGS="$LDFLAG"EXTRA_OPTIONS="";;x86)ARCH="x86"CPU="i686"MARCH="i686"TARGET=i686-linux-androidCC="$TOOLCHAINS/bin/$TARGET$API-clang"CXX="$TOOLCHAINS/bin/$TARGET$API-clang++"LD="$TOOLCHAINS/bin/$TARGET$API-clang"CROSS_PREFIX="$TOOLCHAINS/bin/$TARGET-"#EXTRA_CFLAGS="$CFLAG -march=$MARCH -mtune=intel -mssse3 -mfpmath=sse -m32"EXTRA_CFLAGS="$CFLAG -march=$MARCH -mssse3 -mfpmath=sse -m32"EXTRA_LDFLAGS="$LDFLAG"EXTRA_OPTIONS="--cpu=$CPU ";;x86_64)ARCH="x86_64"CPU="x86-64"MARCH="x86_64"TARGET=$ARCH-linux-androidCC="$TOOLCHAINS/bin/$TARGET$API-clang"CXX="$TOOLCHAINS/bin/$TARGET$API-clang++"LD="$TOOLCHAINS/bin/$TARGET$API-clang"CROSS_PREFIX="$TOOLCHAINS/bin/$TARGET-"#EXTRA_CFLAGS="$CFLAG -march=$CPU -mtune=intel -msse4.2 -mpopcnt -m64"EXTRA_CFLAGS="$CFLAG -march=$CPU -msse4.2 -mpopcnt -m64"EXTRA_LDFLAGS="$LDFLAG"EXTRA_OPTIONS="--cpu=$CPU ";;esacecho "-------- > Start clean workspace"
make cleanecho "-------- > Start build configuration"CONFIGURATION="$COMMON_OPTIONS"CONFIGURATION="$CONFIGURATION --logfile=$CONFIG_LOG_PATH/config_$APP_ABI.log"CONFIGURATION="$CONFIGURATION --prefix=$PREFIX"CONFIGURATION="$CONFIGURATION --libdir=$PREFIX/libs/$APP_ABI"CONFIGURATION="$CONFIGURATION --incdir=$PREFIX/includes/$APP_ABI"CONFIGURATION="$CONFIGURATION --pkgconfigdir=$PREFIX/pkgconfig/$APP_ABI"CONFIGURATION="$CONFIGURATION --cross-prefix=$CROSS_PREFIX"CONFIGURATION="$CONFIGURATION --arch=$ARCH"CONFIGURATION="$CONFIGURATION --sysroot=$SYSROOT"CONFIGURATION="$CONFIGURATION --cc=$CC"CONFIGURATION="$CONFIGURATION --cxx=$CXX"CONFIGURATION="$CONFIGURATION --ld=$LD"# nm 和 stripCONFIGURATION="$CONFIGURATION --nm=$TOOLCHAINS/bin/llvm-nm"CONFIGURATION="$CONFIGURATION --strip=$TOOLCHAINS/bin/llvm-strip"CONFIGURATION="$CONFIGURATION $EXTRA_OPTIONS"echo "-------- > Start config makefile with $CONFIGURATION --extra-cflags=${EXTRA_CFLAGS} --extra-ldflags=${EXTRA_LDFLAGS}"./configure ${CONFIGURATION} \--extra-cflags="$EXTRA_CFLAGS" \--extra-ldflags="$EXTRA_LDFLAGS"echo "-------- > Start make $APP_ABI with -j1"make -j1echo "-------- > Start install $APP_ABI"make installecho "++++++++ > make and install $APP_ABI complete."}build_all() {#配置开源协议声明COMMON_OPTIONS="$COMMON_OPTIONS --enable-gpl"#目标android平台COMMON_OPTIONS="$COMMON_OPTIONS --target-os=android"#取消默认的静态库COMMON_OPTIONS="$COMMON_OPTIONS --disable-static"COMMON_OPTIONS="$COMMON_OPTIONS --enable-shared"COMMON_OPTIONS="$COMMON_OPTIONS --enable-protocols"#开启交叉编译COMMON_OPTIONS="$COMMON_OPTIONS --enable-cross-compile"COMMON_OPTIONS="$COMMON_OPTIONS --enable-optimizations"COMMON_OPTIONS="$COMMON_OPTIONS --disable-debug"#尽可能小COMMON_OPTIONS="$COMMON_OPTIONS --enable-small"COMMON_OPTIONS="$COMMON_OPTIONS --disable-doc"#不要命令（执行文件）COMMON_OPTIONS="$COMMON_OPTIONS --disable-programs" # do not build command line programsCOMMON_OPTIONS="$COMMON_OPTIONS --disable-ffmpeg" # disable ffmpeg buildCOMMON_OPTIONS="$COMMON_OPTIONS --disable-ffplay" # disable ffplay buildCOMMON_OPTIONS="$COMMON_OPTIONS --disable-ffprobe" # disable ffprobe buildCOMMON_OPTIONS="$COMMON_OPTIONS --disable-symver"COMMON_OPTIONS="$COMMON_OPTIONS --disable-network"COMMON_OPTIONS="$COMMON_OPTIONS --disable-x86asm"COMMON_OPTIONS="$COMMON_OPTIONS --disable-asm"#启用COMMON_OPTIONS="$COMMON_OPTIONS --enable-pthreads"COMMON_OPTIONS="$COMMON_OPTIONS --enable-mediacodec"COMMON_OPTIONS="$COMMON_OPTIONS --enable-jni"COMMON_OPTIONS="$COMMON_OPTIONS --enable-zlib"COMMON_OPTIONS="$COMMON_OPTIONS --enable-pic"COMMON_OPTIONS="$COMMON_OPTIONS --enable-muxer=flv"#COMMON_OPTIONS="$COMMON_OPTIONS --enable-avresample"COMMON_OPTIONS="$COMMON_OPTIONS --enable-decoder=h264"COMMON_OPTIONS="$COMMON_OPTIONS --enable-decoder=mpeg4"COMMON_OPTIONS="$COMMON_OPTIONS --enable-decoder=mjpeg"COMMON_OPTIONS="$COMMON_OPTIONS --enable-decoder=png"COMMON_OPTIONS="$COMMON_OPTIONS --enable-decoder=vorbis"COMMON_OPTIONS="$COMMON_OPTIONS --enable-decoder=opus"COMMON_OPTIONS="$COMMON_OPTIONS --enable-decoder=flac"echo "COMMON_OPTIONS=$COMMON_OPTIONS"echo "PREFIX=$PREFIX"echo "CONFIG_LOG_PATH=$CONFIG_LOG_PATH"mkdir -p ${CONFIG_LOG_PATH}#build "armeabi-v7a"build "arm64-v8a"build "x86"build "x86_64"
}echo "-------- Start --------"
build_all
echo "-------- End --------"