libjpeg-turbo androd 编译

官方编译文档： 

https://github.com/libjpeg-turbo/libjpeg-turbo/blob/dev/BUILDING.md#building-libjpeg-turbo-for-android 

Building libjpeg-turbo for Android

Building libjpeg-turbo for Android platforms requires v13b or later of the Android NDK.

ARMv7 (32-bit)

The following is a general recipe script that can be modified for your specific needs.

# Set these variables to suit your needs
NDK_PATH={full path to the NDK directory-- for example,
  /opt/android/android-ndk-r16b}
TOOLCHAIN={"gcc" or "clang"-- "gcc" must be used with NDK r16b and earlier,
  and "clang" must be used with NDK r17c and later}
ANDROID_VERSION={the minimum version of Android to support-- for example,
  "16", "19", etc.}

cd {build_directory}
cmake -G"Unix Makefiles" \
  -DANDROID_ABI=armeabi-v7a \
  -DANDROID_ARM_MODE=arm \
  -DANDROID_PLATFORM=android-${ANDROID_VERSION} \
  -DANDROID_TOOLCHAIN=${TOOLCHAIN} \
  -DCMAKE_ASM_FLAGS="--target=arm-linux-androideabi${ANDROID_VERSION}" \
  -DCMAKE_TOOLCHAIN_FILE=${NDK_PATH}/build/cmake/android.toolchain.cmake \
  [additional CMake flags] {source_directory}
make

ARMv8 (64-bit)

The following is a general recipe script that can be modified for your specific needs.

# Set these variables to suit your needs
NDK_PATH={full path to the NDK directory-- for example,
  /opt/android/android-ndk-r16b}
TOOLCHAIN={"gcc" or "clang"-- "gcc" must be used with NDK r14b and earlier,
  and "clang" must be used with NDK r17c and later}
ANDROID_VERSION={the minimum version of Android to support.  "21" or later
  is required for a 64-bit build.}

cd {build_directory}
cmake -G"Unix Makefiles" \
  -DANDROID_ABI=arm64-v8a \
  -DANDROID_ARM_MODE=arm \
  -DANDROID_PLATFORM=android-${ANDROID_VERSION} \
  -DANDROID_TOOLCHAIN=${TOOLCHAIN} \
  -DCMAKE_ASM_FLAGS="--target=aarch64-linux-android${ANDROID_VERSION}" \
  -DCMAKE_TOOLCHAIN_FILE=${NDK_PATH}/build/cmake/android.toolchain.cmake \
  [additional CMake flags] {source_directory}
make

 1、下载源码：

git clone https://github.com/libjpeg-turbo/libjpeg-turbo.git
cd libjpeg-turbo/

2、新建脚本android_build.sh，输入以下内容：

#!/bin/bash
# Set these variables to suit your needs
NDK_PATH=$NDK_HOME
BUILD_PLATFORM=darwin-x86_64
TOOLCHAIN_VERSION=4.9
ANDROID_VERSION=14
 
#添加cmake环境变量
export PATH="/Applications/CMake.app/Contents/bin":"$PATH"
SOURCE_DIR=$(pwd)
PREFIX=$(pwd)/android
 
 
# It should not be necessary to modify the rest
HOST=arm-linux-androideabi
SYSROOT=${NDK_PATH}/platforms/android-${ANDROID_VERSION}/arch-arm
export CFLAGS="-march=armv7-a -mfloat-abi=softfp -fprefetch-loop-arrays \
  -D__ANDROID_API__=${ANDROID_VERSION} --sysroot=${SYSROOT} \
  -isystem ${NDK_PATH}/sysroot/usr/include \
  -isystem ${NDK_PATH}/sysroot/usr/include/${HOST}"
export LDFLAGS=-pie
TOOLCHAIN=${NDK_PATH}/toolchains/${HOST}-${TOOLCHAIN_VERSION}/prebuilt/${BUILD_PLATFORM}
 
cat <<EOF >toolchain.cmake
set(CMAKE_SYSTEM_NAME Linux)
set(CMAKE_SYSTEM_PROCESSOR arm)
set(CMAKE_C_COMPILER ${TOOLCHAIN}/bin/${HOST}-gcc)
set(CMAKE_FIND_ROOT_PATH ${TOOLCHAIN}/${HOST})
EOF
 
cmake -G"Unix Makefiles" -DCMAKE_TOOLCHAIN_FILE=toolchain.cmake \
    -DCMAKE_POSITION_INDEPENDENT_CODE=1 \
    -DCMAKE_INSTALL_PREFIX=${PREFIX} \
    ${SOURCE_DIR}
 
make clean
make
make install

3、运行android_build.sh

chmod 777 ./android_build.sh
./android_build.sh

编辑成功后会在android目录下生成include、lib等结果

4、编写jni给java层调用

1) 新建Android Studio项目，选择Include C++ Support 

2) Copy 第三步的结果include和lib目录到app/src/main/cpp下面