交叉编译FFmpeg

• 搭建编译环境
• 构建编译脚本

一. 搭建编译环境

1. 安装Ubuntu-18.04.4-desktop-amd64

Ubuntu环境下命令安装：
apt-get install -y make 
apt-get install -y unzip

2. 下载NDK，这里选用的是ndk-r21d

3. 下载FFmpeg

二. 构建编译脚本

#!/bin/sh
echo Start building ff.
NDK=/home/hhu/share/transfer/android-ndk-r21b
ANDROID_VERSION=21
TOOLCHAIN_VERSION=4.9
BUILD_PLATFORM=linux-x86_64
ARCH=arm
HOST=arm-linux
ANDROID_ARCH_ABI=armeabi
SYSROOT=$NDK/toolchains/llvm/prebuilt/linux-x86_64/sysroot
TOOLCHAIN=$NDK/toolchains/llvm/prebuilt/linux-x86_64/bin
PREFIX=$(pwd)/android/${ANDROID_VERSION}/$ANDROID_ARCH_ABI
ADDI_LDFLAGS="-fPIE -pie"
ADDI_CFLAGS="-fPIE -pie -march=armv7-a -mfloat-abi=softfp -mfpu=neon"
build() {
./configure \
  --prefix=$PREFIX \
  --toolchain=clang-usan \
  --target-os=android \
  --arch=$ARCH \
  --cpu=armv7-a  \
  --sysroot=$SYSROOT \
  --cc=$TOOLCHAIN/armv7a-linux-androideabi21-clang \
  --cxx=$TOOLCHAIN/armv7a-linux-androideabi21-clang++ \
  --strip=$TOOLCHAIN/arm-linux-androideabi-strip \
  --extra-cflags="$ADDI_CFLAGS" \
  --extra-ldflags="$ADDI_LDFLAGS" \
  --enable-neon \
  --enable-hwaccels \
  --enable-gpl \
  --enable-jni \
  --enable-mediacodec \
  --enable-decoder=h264_mediacodec \
  --enable-hwaccel=h264_mediacodec \
  --enable-decoder=hevc_mediacodec \
  --enable-decoder=mpeg4_mediacodec \
  --enable-decoder=vp8_mediacodec \
  --enable-decoder=vp9_mediacodec \
  --enable-cross-compile \
  --enable-ffmpeg \
  --enable-shared \
  --disable-static \
  --disable-debug \
  --disable-static \
  --disable-doc \
  --disable-ffplay \
  --disable-ffprobe \
  --disable-postproc \
  --disable-avdevice \
  --disable-symver \
  --disable-stripping

  make clean
  make -j4
  make install
  echo "$ANDROID_ARCH_ABI installed"
}
build