最全的FFmpeg编译for Android

首先，如果编译环境是ubuntu，执行sudo apt install build-essential确保C/C++编译环境安装好了。

然后，修改FFmpeg根目录文件configure里so生成的文件格式, 为的是生成的so没有版本号：

SLIBNAME_WITH_MAJOR='$(SLIBNAME).$(LIBMAJOR)'
LIB_INSTALL_EXTRA_CMD='$$(RANLIB) "$(LIBDIR)/$(LIBNAME)"'
SLIB_INSTALL_NAME='$(SLIBNAME_WITH_VERSION)'
SLIB_INSTALL_LINKS='$(SLIBNAME_WITH_MAJOR) $(SLIBNAME)'

修改为如下：

SLIBNAME_WITH_MAJOR='$(SLIBPREF)$(FULLNAME)-$(LIBMAJOR)$(SLIBSUF)'
LIB_INSTALL_EXTRA_CMD='$$(RANLIB)"$(LIBDIR)/$(LIBNAME)"'
SLIB_INSTALL_NAME='$(SLIBNAME_WITH_MAJOR)'
SLIB_INSTALL_LINKS='$(SLIBNAME)'

然后，在FFmpeg根目录下创建一个shell文件叫build_android.sh, 内容如下，作用是Android生成的so需要配合NDK配置别的参数，比如：toolchain、sysroot, cc和cxx路径等

#!/bin/bash

export NDK=/home/phil/Android/Sdk/ndk/22.1.7171670
export TOOLCHAIN=$NDK/toolchains/llvm/prebuilt/linux-x86_64
export SYSROOT=$NDK/toolchains/llvm/prebuilt/linux-x86_64/sysroot
export API=21

function build_android {
    echo "Compiling FFmpeg for $CPU"
    ./configure \
        --prefix=$PREFIX \
        --libdir=$LIB_DIR \
        --enable-neon \
        --enable-hwaccels \
        --enable-gpl \
        --enable-postproc \
        --enable-shared \
        --enable-jni \
        --enable-mediacodec \
        --disable-decoders \
        --enable-decoder=h264_mediacodec \
        --enable-decoder=h264 \
        --enable-decoder=mpeg4 \
        --enable-decoder=aac \
        --enable-decoder=aac_latm \
        --enable-decoder=mjpeg \
        --enable-decoder=png \
        --enable-decoder=mpeg4_mediacodec \
        --disable-encoders \
        --enable-encoder=h264_v4l2m2m \
        --disable-demuxers \
        --enable-demuxer=rtsp \
        --enable-demuxer=rtp \
        --enable-demuxer=flv \
        --enable-demuxer=h264 \
        --disable-muxers \
        --enable-muxer=rtsp \
        --enable-muxer=rtp \
        --enable-muxer=flv \
        --enable-muxer=h264 \
        --disable-parsers \
        --enable-parser=mpeg4video \
        --enable-parser=aac \
        --enable-parser=h264 \
        --enable-parser=vp9 \
        --disable-protocols \
        --enable-protocol=rtmp \
        --enable-protocol=rtp \
        --enable-protocol=tcp \
        --enable-protocol=udp \
        --disable-bsfs \
        --disable-indevs \
        --enable-indev=v4l2 \
        --disable-outdevs \
        --disable-filters \
        --disable-postproc \
        --disable-static \
        --disable-doc \
        --disable-ffmpeg \
        --disable-ffplay \
        --disable-ffprobe \
        --disable-avdevice \
        --disable-symver \
        --target-os=android \
        --enable-small \
        --disable-swresample \
        --disable-postproc \
        --disable-programs \
        --disable-runtime-cpudetect \
        --disable-htmlpages \
        --disable-manpages \
        --disable-podpages \
        --disable-txtpages \
        --disable-stripping \
        --arch=$ARCH \
        --cpu=$CPU \
        --cc=$CC \
        --cxx=$CXX \
        --enable-cross-compile \
        --sysroot=$SYSROOT \
        --extra-cflags="-Os -fpic $OPTIMIZE_CFLAGS" \
        --extra-ldflags="$ADDI_LDFLAGS" \
        --disable-x86asm \
        --disable-asm \
        $COMMON_FF_CFG_FLAGS
    make clean
    make -j8
    make install
    echo "The Compilation of FFmpeg for Android[$CPU] is completed.\n"
}

# armv8-a
OUTPUT_FOLDER="arm64-v8a"
ARCH=arm64
CPU="armv8-a"
TOOL_CPU_NAME=aarch64
TOOL_PREFIX=${TOOLCHAIN}/bin/${TOOL_CPU_NAME}-linux-android
CC="${TOOL_PREFIX}${API}-clang"
CXX="${TOOL_PREFIX}${API}-clang++"
PREFIX="${PWD}/output/${OUTPUT_FOLDER}"
LIB_DIR="${PWD}/output/libs/${OUTPUT_FOLDER}"
OPTIMIZE_CFLAGS="-march=${CPU}"
build_android

# armv7-a
OUTPUT_FOLDER="armeabi-v7a"
ARCH="arm"
CPU="armv7-a"
TOOL_CPU_NAME=armv7a
TOOL_PREFIX=${TOOLCHAIN}/bin/${TOOL_CPU_NAME}-linux-android
CC="$TOOLCHAIN/bin/armv7a-linux-androideabi${API}-clang"
CXX="$TOOLCHAIN/bin/armv7a-linux-androideabi${API}-clang++"
PREFIX="${PWD}/output/${OUTPUT_FOLDER}"
LIB_DIR="${PWD}/output/libs/${OUTPUT_FOLDER}"
OPTIMIZE_CFLAGS="-march=${CPU}"
build_android

# x86
OUTPUT_FOLDER="x86"
ARCH="x86"
CPU="x86"
TOOL_CPU_NAME="i686"
TOOL_PREFIX=${TOOLCHAIN}/bin/${TOOL_CPU_NAME}-linux-android
CC="${TOOL_PREFIX}${API}-clang"
CXX="${TOOL_PREFIX}${API}-clang++"
PREFIX="${PWD}/output/${OUTPUT_FOLDER}"
LIB_DIR="${PWD}/output/libs/${OUTPUT_FOLDER}"
OPTIMIZE_CFLAGS="-march=i686 -mtune=intel -mssse3 -mfpmath=sse -m32"
build_android

#  x86_64
OUTPUT_FOLDER="x86_64"
ARCH="x86_64"
CPU="x86-64"
TOOL_CPU_NAME="x86_64"
TOOL_PREFIX=${TOOLCHAIN}/bin/${TOOL_CPU_NAME}-linux-android
CC="${TOOL_PREFIX}${API}-clang"
CXX="${TOOL_PREFIX}${API}-clang++"
PREFIX="${PWD}/output/${OUTPUT_FOLDER}"
LIB_DIR="${PWD}/output/libs/${OUTPUT_FOLDER}"
OPTIMIZE_CFLAGS="-march=${CPU}"
build_android

最后，按你的需要注释掉部分编译目标的脚本来达到编译不同cpu架构的so，在FFmpeg跟目录下执行"./build_android.sh"即可等待编译完成，如有报错再查看NDK路径是错误，如果是用mac os编译那么TOOLCHAIN和SYSROOT里的linux-x86_64需要改为darwin-x86_64。
FFmpeg编出来的so如果还嫌弃体积大或者某项功能不支持，你还得查阅configure里更详细的配置项，然后按需配置来达到减小so体积或者支持新功能。