项目源码
FFmpeg开发文档
编译过程中涉及到很多ndk中的so库和头文件以及交叉编译的工具，在命令执行的时候会在ndk相应的目录下去查找，所以我们可以使用export命令事先将这些路径设置到环境变量，使用的时候可以很方便的找到
//NDK加入环境变量，以我的ndk存放路径为例
export NDK=/root/renzhenming/ffmpeg/android-ndk-r14b
//ndk的platforms文件夹中存放的是各个版本架构下的so库和头文件
export PLATFORM=$NDK/platforms/android-21/arch-arm
//指定交叉编译工具的路径
export TOOLCHAIN=$NDK/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64
//指定输出类型,以armv7-a为例
export CPU=armv7-a
//指定so文件编译后的输出路径
export PREFIX=./android/$CPU
相关命令解析
脚本中定义了一个方法build_ffmpeg，最终它被调用两次生成支持neon和硬解码的so库和不支持neon和硬解码的so库
configure ：是ffmpeg中已有的一个配置文件，我们的脚本其实也就是去执行这个文件，所有生成so的工作都在这里进行
prefix : 指定最终生成的so的安装目录
target-os ： 指定目标系统，早期很多脚本在2.x上把这个指定为linux,可以，但是ffmpeg更新之后，在3.x的版本之上会导致问题，头文件找不到之类的，这是一点差异
cross-prefix：指定交叉编译的前缀，在交叉编译的情况下，比如交叉编译使用的gcc，那么会在gcc前加上这个前缀，就是一个完整的gcc工具的路径，可以通过这个路径找到这个工具（/home/renzhenming/ffmpeg/android-ndk-r14b/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64/bin/arm-linux-androideabi-gcc）
sysroot:指定这套系统依赖的库和头文件位置，就是我们配置的PLATFORMS，交叉编译在本系统中是找不到这些库的，可以把这些库看作是交叉编译的环境。如果在编译时指定了-sysroot就是为编译时指定了逻辑目录。编译过程中需要引用的库，头文件，如果要到/usr/include目录下去找的情况下，则会在前面加上逻辑目录。
extra-cflags：是使用$（CC）(cc中指定的编译器)编译C文件的选项,给gcc提供的一系列参数，这个可配可不配。 -fPIC编译动态链接库的参数， -mfpu指定协处理器，-mfloat-abi=softfp软浮点
cc : linux下cc一般是一个符号连接，指向gcc，一般是makefile里面的一个名字，即宏定义，就把他当做一个已经定义好的变量，可以指定编译器即可，ffmpeg是c语言写的，这里指定gcc为编译器，g++是c++编译器
nm：符号查看工具，nm 命令显示关于指定 File 中符号的信息，文件可以是对象文件、可执行文件或对象文件库。如果文件没有包含符号信息，nm 命令报告该情况，但不把它解释为出错条件。 nm 命令缺省情况下报告十进制符号表示法下的数字值。
enable-shared：编译成动态库，大概在3.4之前的ffmpeg版本，我们编译的时候需要修改configure文件中的一些参数，因为默认生成的so库文件名有问题，无法直接调用，3.4不再需要手动修改
enable-runtime-cpudetect ：开启运行期cpu检测，不支持的指令可以自动被替换
enable-gpl：ffmpeg要求商用中如果开启这个gpl，那么你的代码要开源，否则不准开启，不开启有些库无法使用
enable-small：打出来的so更小
enable-asm:允许汇编，指令优化
支持硬解码，打开后jni可以调用java的源码
--enable-jni
--enable-mediacodec
解码器
--enable-decoder=h264_mediacodec
硬件加速
--enable-hwaccel=h264_mediacodec \
完整的编译脚本
这个脚本目前经过验证，可以正常的进行编译3.4版本和3.4.4版本的ffmpeg,前提是需要保证每一个配置参数的正确，一般如果编译出现问题，大多是由于ndk的几个路径错误，NDK/PLATFORM/TOOLCHAIN这三个变量核对一下是否和你的ndk目录一致
#!/bin/bash
echo "进入编译ffmpeg脚本"
NDK=/home/ren/ffmpeg/android-ndk-r14b
#5.0
PLATFORM=$NDK/platforms/android-21/arch-arm
TOOLCHAIN=$NDK/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64
CPU=arm
#输出路径
PREFIX=./android/$CPU
function build_ffmpeg
{
echo "开始编译ffmpeg"
./configure \
--prefix=$PREFIX \
--target-os=android \
--cross-prefix=$TOOLCHAIN/bin/arm-linux-androideabi- \
--arch=arm \
--cpu=$CPU \
--extra-libs=-lgcc \
--sysroot=$PLATFORM \
--extra-cflags="$CFLAG" \
--cc=$TOOLCHAIN/bin/arm-linux-androideabi-gcc \
--nm=$TOOLCHAIN/bin/arm-linux-androideabi-nm \
--enable-shared \
--enable-runtime-cpudetect \
--enable-gpl \
--enable-small \
--enable-cross-compile \
--disable-debug \
--disable-static \
--disable-doc \
--disable-ffmpeg \
--disable-ffplay \
--disable-ffprobe \
--disable-ffserver \
--disable-postproc \
--disable-avdevice \
--disable-symver \
--disable-stripping \
$ADD
#开启16个线程
make -j16
make install
echo "编译结束！"
}
###########################################################
echo "编译支持neon和硬解码"
CPU=armv7-a
PREFIX=./android/armv7-a-neon-hard
#-fPIC 作用于编译阶段，告诉编译器产生与位置无关代码(Position-Independent Code)，
#则产生的代码中，没有绝对地址，全部使用相对地址，故而代码可以被
#加载器加载到内存的任意位置，都可以正确的执行。这正是共享库所要
#求的，共享库被加载时，在内存的位置不是固定的。
#如果不加-fPIC,则加载.so文件的代码段时,代码段引用的数据对象需要重
#定位, 重定位会修改代码段的内容,这就造成每个使用这个.so文件代码段
#的进程在内核里都会生成这个.so文件代码段的copy.每个copy都不一样,
#取决于 这个.so文件代码段和数据段内存映射的位置. 也就是
#不加fPIC编译出来的so,是要再加载时根据加载到的位置再次重定位的.(因
#为它里面的代码并不是位置无关代码)
#如果被多个应用程序共同使用,那么它们必须每个程序维护一份.so的代码
#副本了.(因为.so被每个程序加载的位置都不同,显然这些重定位后的代码
#也不同,当然不能共享)
#我们总是用fPIC来生成so,也从来不用fPIC来生成.a;
#-mfpu=neon 浮点协处理器指令，使用硬件浮点的时候，我们需要给编译器传递一些参数，让编译器编译出硬件浮点单元处理器能识别的指令。参数-mfpu就是用来指定要产生哪种硬件浮点运算指令,常用的右vfp和neon等.
#-mfloat-abi=soft使用这个参数时，其将调用软浮点库(softfloat lib)来持
#对浮点的运算，GCC编译器已经有这个库了，一般在libgcc里面。这
#时根本不会使用任何浮点指令，而是采用常用的指令来模拟浮点运算。
#但使用的ARM芯片不支持硬浮点时，可以考虑使用这个参数。
#-mfloat-abi=softfp
#-mfloat-abi=hard
#这两个参数都用来产生硬浮点指令，至于产生哪种类型的硬浮点指令，
#需要由-mfpu=xxx参数来指令。这两个参数不同的地方是：
#-mfloat-abi=softfp生成的代码采用兼容软浮点调用接口(即使用-mfloat-abi=soft时的调用接口)，
#这样带来的好处是：兼容性和灵活性。库可以采用-mfloat-abi=soft编
#译，而关键的应用程序可以采用-mfloat-abi=softfp来编译。特别是在库
#由第三方发布的情况下。
#-mfloat-abi=hard生成的代码采用硬浮点(FPU)调用接口。这样要求所有
#库和应用程序必须采用这同一个参数来编译，否则连接时会出现接口不
#兼容错误。
#默认情况下，gcc在下面目录中搜索头文件：
#/usr/local/include/
#/usr/include/
#在下面目录中搜索库：
#/usr/local/lib/
#/usr/lib/
CFLAG="-I$PLATFORM/usr/include -fPIC -DANDROID -mfpu=neon -mfloat-abi=softfp "
#--enable-asm程序集优化
ADD="--enable-asm \
#neon指令集，开发者可以为需要高性能的应用程序编写NEON指令来实现相应功能
#NEON:SIMD(SingleInstructionMultipleData单指令多重数据)指令集，其针对多媒体
#和讯号处理程式具备标准化的加速能力。
--enable-neon \
#添加jni支持，那么ffmpeg可以调用java代码
--enable-jni \
# 硬解码相关
--enable-mediacodec \
--enable-decoder=h264_mediacodec \
--enable-hwaccel=h264_mediacodec "
build_ffmpeg
###########################################################
echo "编译不支持neon和硬解码"
CPU=armv7-a
PREFIX=./android/$CPU
#VFP:(VectorFloatPoint),向量浮点运算单元，arm11（s3c6410支持
#VFPv2），Cortex-#A8（s5pv210）支持VFPv3.
#-mfpu=name（neonorvfpvx）指定FPU单元
#-mfloat-abi=name（soft、hard、softfp）：指定软件浮点或硬件浮点或兼容软浮点调用
#接口
#如果只指定-mfpu，那么默认编译不会选择选择硬件浮点指令集
#如果只指定-mfloat-abi=hard或者softfp，那么编译会使用硬件浮点指令集
CFLAG="-I$PLATFORM/usr/include -fPIC -DANDROID -mfpu=vfp -mfloat-abi=softfp "
ADD=
build_ffmpeg
ffmpeg编译参数解析
来自./configure --help
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 filters
Standard 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 [/usr/local]
--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 paths
not part of the dynamic linker search path
use rpath when linking programs (USE WITH CARE)
--install-name-dir=DIR Darwin directory name for installed targets
Licensing options:
--enable-gpl allow use of GPL code, the resulting libs
and binaries will be under GPL [no]
--enable-version3 upgrade (L)GPL to version 3 [no]
--enable-nonfree allow use of nonfree code, the resulting libs
and 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 build
--disable-ffserver disable ffserver build
Documentation 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 pages
Component 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
--enable-avresample enable libavresample build [no]
--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-lzo disable LZO decoder 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 libavutil
Individual 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 filters
--disable-v4l2_m2m disable V4L2 mem2mem code [autodetect]
External library support:
Using any of the following switches will allow FFmpeg to link to the
corresponding external library. All the components depending on that library
will become enabled, if all their other dependencies are met and they are not
explicitly disabled. E.g. --enable-libwavpack will enable linking to
libwavpack and allow the libwavpack encoder to be built, unless it is
specifically disabled with --disable-encoder=libwavpack.
Note that only the system libraries are auto-detected. All the other external
libraries must be explicitly enabled.
Also note that the following help text describes the purpose of the libraries
themselves, 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 support
if openssl, librtmp or gmp is not used [no]
--enable-gmp enable gmp, needed for rtmp(t)e support
if openssl or librtmp is not used [no]
--enable-gnutls enable gnutls, needed for https support
if openssl is not used [no]
--disable-iconv disable iconv [autodetect]
--disable-jack disable libjack support [autodetect]
--enable-jni enable JNI support [no]
--enable-ladspa enable LADSPA audio filtering [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-libdc1394 enable IIDC-1394 grabbing using libdc1394
and 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-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-libkvazaar enable HEVC encoding via libkvazaar [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-libopus enable Opus de/encoding via libopus [no]
--enable-libpulse enable Pulseaudio input via libpulse [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-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-libssh enable SFTP protocol via libssh [no]
--enable-libtesseract enable Tesseract, needed for ocr filter [no]
--enable-libtheora enable Theora encoding via libtheora [no]
--enable-libtwolame enable MP2 encoding via libtwolame [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-libwavpack enable wavpack encoding via libwavpack [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-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 [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]
--disable-lzma disable lzma [autodetect]
--enable-decklink enable Blackmagic DeckLink I/O support [no]
--enable-libndi_newtek enable Newteck NDI I/O support [no]
--enable-mediacodec enable Android MediaCodec support [no]
--enable-libmysofa enable libmysofa, needed for sofalizer filter [no]
--enable-openal enable OpenAL 1.1 capture support [no]
--enable-opencl enable OpenCL code
--enable-opengl enable OpenGL rendering [no]
--enable-openssl enable openssl, needed for https support
if gnutls is not used [no]
--disable-sndio disable sndio support [autodetect]
--disable-schannel disable SChannel SSP, needed for TLS support on
Windows if openssl and gnutls are not used [autodetect]
--disable-sdl2 disable sdl2 [autodetect]
--disable-securetransport disable Secure Transport, needed for TLS support
on OSX if openssl and gnutls are not used [autodetect]
--disable-xlib disable xlib [autodetect]
--disable-zlib disable zlib [autodetect]
The following libraries provide various hardware acceleration features:
--disable-audiotoolbox disable Apple AudioToolbox code [autodetect]
--disable-cuda disable dynamically linked Nvidia CUDA code [autodetect]
--enable-cuda-sdk enable CUDA features that require the CUDA SDK [no]
--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]
--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-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-vaapi disable Video Acceleration API (mainly Unix/Intel) code [autodetect]
--disable-vda disable Apple Video Decode Acceleration 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 []
--cpu=CPU select the minimum required CPU (affects
instruction selection, may crash on older CPUs)
--cross-prefix=PREFIX use PREFIX for compilation tools []
--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-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
--nm=NM use nm tool NM [nm -g]
--ar=AR use archive tool AR [ar]
--as=AS use assembler AS []
--ln_s=LN_S use symbolic link tool LN_S [ln -s -f]
--strip=STRIP use strip tool STRIP [strip]
--windres=WINDRES use windows resource compiler WINDRES [windres]
--x86asmexe=EXE use nasm-compatible assembler EXE [nasm]
--cc=CC use C compiler CC [gcc]
--cxx=CXX use C compiler CXX [g++]
--objcc=OCC use ObjC compiler OCC [gcc]
--dep-cc=DEPCC use dependency generator DEPCC [gcc]
--nvcc=NVCC use Nvidia CUDA compiler NVCC [nvcc]
--ld=LD use linker LD []
--pkg-config=PKGCONFIG use pkg-config tool PKGCONFIG [pkg-config]
--pkg-config-flags=FLAGS pass additional flags to pkgconf []
--ranlib=RANLIB use ranlib RANLIB [ranlib]
--doxygen=DOXYGEN use DOXYGEN to generate API doc [doxygen]
--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-libs=HLIBS use libs HLIBS when linking for host
--host-os=OS compiler host OS []
--extra-cflags=ECFLAGS add ECFLAGS to CFLAGS []
--extra-cxxflags=ECFLAGS add ECFLAGS to CXXFLAGS []
--extra-objcflags=FLAGS add FLAGS to OBJCFLAGS []
--extra-ldflags=ELDFLAGS add ELDFLAGS to LDFLAGS []
--extra-ldexeflags=ELDFLAGS add ELDFLAGS to LDEXEFLAGS []
--extra-ldlibflags=ELDFLAGS add ELDFLAGS to LDLIBFLAGS []
--extra-libs=ELIBS add ELIBS []
--extra-version=STRING version string suffix []
--optflags=OPTFLAGS override optimization-related compiler flags
--nvccflags=NVCCFLAGS override nvcc flags [-gencode arch=compute_30,code=sm_30 -O2]
--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 variables
Advanced 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-reader
disable buffer boundary checking in bitreaders
(faster, but may crash)
--sws-max-filter-size=N the max filter size swscale uses [256]
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-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 SIMD optimizations
--disable-fast-unaligned consider unaligned accesses slow
Developer options (useful when working on FFmpeg itself):
--disable-debug disable debugging symbols
--enable-debug=LEVEL set the debug level []
--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 memory
leaks 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
$FATE_SAMPLES at make invocation time.
--enable-neon-clobber-test check NEON registers for clobbering (should be
used only for debugging purposes)
--enable-xmm-clobber-test check XMM registers for clobbering (Win64-only;
should be used only for debugging purposes)
--enable-random randomly enable/disable components
--disable-random
--enable-random=LIST randomly enable/disable specific components or
--disable-random=LIST component groups. LIST is a comma-separated list
of NAME[:PROB] entries where NAME is a component
(group) and PROB the probability associated with
NAME (default 0.5).
--random-seed=VALUE seed value for --enable/disable-random
--disable-valgrind-backtrace do not print a backtrace under Valgrind
(only applies to --disable-optimizations builds)
--enable-osfuzz Enable building fuzzer tool
--libfuzzer=PATH path to libfuzzer
--ignore-tests=TESTS comma-separated list (without "fate-" prefix
in the name) of tests whose result is ignored
--enable-linux-perf enable Linux Performance Monitor API
经试验，最简脚本为：
#!/bin/bash
echo "进入编译ffmpeg脚本"
NDK=/Users/renzm/rzm/android-ndk-r12b
#5.0
PLATFORM=$NDK/platforms/android-21/arch-arm
TOOLCHAIN=$NDK/toolchains/arm-linux-androideabi-4.9/prebuilt/darwin-x86_64
CPU=armv7-a
#输出路径
PREFIX=./android/$CPU
function build_ffmpeg
{
echo "开始编译ffmpeg"
./configure \
--prefix=$PREFIX \
--target-os=android \
--cross-prefix=$TOOLCHAIN/bin/arm-linux-androideabi- \
--sysroot=$PLATFORM \
--arch=arm \
--cpu=$CPU \
--enable-shared \
--disable-static
#开启16个线程
make -j16
make install
echo "编译结束！"
}
build_ffmpeg
