libjpeg的编译和使用进行图片压缩

来点前奏说明

当你打开这个文档的时候，你已经做好准备了，话不多说开搞。
本文以https://github.com/libjpeg-turbo/libjpeg-turbo
的默认master分支进行编译，以Ubuntu进行演示编译过程。

1、硬件要求：

系统：  Unbuntu

2、软件要求：

sudo apt install git
sudo apt install yasm
sudo apt install vim
sudo snap install cmake 

NDK版本要求：NDK 14及其以前的版本

下载NDK 14以前包括14的版本

3、libjpeg 编译

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

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

先放上我已经写好的shell脚本，以ARMv8 (64-bit)写的,为命名为build_arm64_android.sh

#!/bin/bash
# Set these variables to suit your needs
NDK_PATH=/home/zhangbin/Android/Sdk/ndk-bundle
#TOOLCHAIN={"gcc" or "clang"-- "gcc" must be used with NDK r14b and earlier,and "clang" must be used with NDK r17c and later}
TOOLCHAIN=gcc
#ANDROID_VERSION={the minimum version of Android to support.  "21" or lateris required for a 64-bit build.}
ANDROID_VERSION=21
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 \

ARMv7 (32-bit)

# 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)

# 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

执行上面写好的脚本，我的脚本命名为build_arm64_android.sh

./build_arm64_android.sh

Installing libjpeg-turbo

sudo make install

成功的标志，a文件为静态库，so文件为动态库

目录下面生成  libjpeg.a 和  libturbojpeg.a

4、libjpeg 使用