最近因为项目需要，引入了opencv2.framework，opencv2.framework中使用的libjpeg库版本号是9.0。而我的项目中使用的还是版本还是6.2，导致使用部分功能时报错：
Wrong JPEG library version: library is 62, caller expects 90
所以需要把libjpeg库升级到9.0。当前我使用的Xcode版本是11.2.1，在网上找到的编译脚本报错，故针对我的环境做了部分修改，具体修改我在脚本中已经注释说明。
脚本代码如下：
该脚本会自动下载对应的libjpeg库。只需要cd到指定的目录，然后执行:
bash xxx/build_ios_libjpeg_a.sh
#!/bin/bash
#感谢 zark_fun 提供的脚本
#参照 https://gist.github.com/eminarcissus/108c2ac0c7c9124b65709b44edabd424 做的微调。
#zark_fun 的博客地址：https://blog.csdn.net/zhangkai19890929/article/details/85598493
# Builds a Libjpeg framework for the iPhone and the iPhone Simulator.
# Creates a set of universal libraries that can be used on an iPhone and in the
# iPhone simulator. Then creates a pseudo-framework to make using libjpeg in Xcode
# less painful.
#
# To configure the script, define:
# IPHONE_SDKVERSION: iPhone SDK version (e.g. 8.0)
#
# Then go get the source tar.bz of the libjpeg you want to build, shove it in the
# same directory as this script, and run "bash libjpeg.sh". Grab a cuppa. And voila.
#===============================================================================
# 需要编译的libjpeg版本 可以在 http://www.ijg.org/files 看到所有libjpeg的版本
# 编译6.2版本会报错，因为没用到，没有研究
: ${LIB_VERSION:=9}
# Current iPhone SDK
# 自动获取当前版本，这个和你Xcode设置里面选择的 Command Line Tools 有关，建议不要使用
# : ${IPHONE_SDKVERSION:=`xcodebuild -showsdks | grep iphoneos | egrep "[[:digit:]]+\.[[:digit:]]+" -o | tail -1`}
# Specific iPhone SDK
# libjpeg最低支持的iOS系统，不要超过10，会提示不支持
: ${IPHONE_SDKVERSION:=8.0}
: ${XCODE_ROOT:=`xcode-select -print-path`}
: ${TARBALLDIR:=`pwd`}
: ${SRCDIR:=`pwd`/src}
: ${IOSBUILDDIR:=`pwd`/ios/build}
: ${OSXBUILDDIR:=`pwd`/osx/build}
: ${PREFIXDIR:=`pwd`/ios/prefix}
: ${IOSFRAMEWORKDIR:=`pwd`/ios/framework}
: ${OSXFRAMEWORKDIR:=`pwd`/osx/framework}
LIB_TARBALL=$TARBALLDIR/jpegsrc.v$LIB_VERSION.tar.gz
LIB_SRC=$SRCDIR/jpeg-${LIB_VERSION}
#===============================================================================
ARM_DEV_CMD="xcrun --sdk iphoneos"
SIM_DEV_CMD="xcrun --sdk iphonesimulator"
#===============================================================================
# Functions
#===============================================================================
abort()
{
echo
echo "Aborted: $@"
exit 1
}
doneSection()
{
echo
echo "================================================================="
echo "Done"
echo
}
#===============================================================================
cleanEverythingReadyToStart()
{
echo Cleaning everything before we start to build...
rm -rf iphone-build iphonesim-build
rm -rf $IOSBUILDDIR
rm -rf $PREFIXDIR
rm -rf $IOSFRAMEWORKDIR/$FRAMEWORK_NAME.framework
doneSection
}
#===============================================================================
downloadLibjpeg()
{
if [ ! -s $LIB_TARBALL ]; then
echo "Downloading libjpeg ${LIB_VERSION}"
curl -L -o $LIB_TARBALL http://www.ijg.org/files/jpegsrc.v${LIB_VERSION}.tar.gz
fi
doneSection
}
#===============================================================================
unpackLibjpeg()
{
[ -f "$LIB_TARBALL" ] || abort "Source tarball missing."
echo Unpacking libjpeg into $SRCDIR...
[ -d $SRCDIR ] || mkdir -p $SRCDIR
[ -d $LIB_SRC ] || ( cd $SRCDIR; tar xfj $LIB_TARBALL )
[ -d $LIB_SRC ] && echo " ...unpacked as $LIB_SRC"
doneSection
}
#===============================================================================
buildLibjpegForIPhoneOS()
{
export CC=$XCODE_ROOT/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang
export CC_BASENAME=clang
export CXX=$XCODE_ROOT/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++
export CXX_BASENAME=clang++
#编译模拟器版本
echo Building Libjpeg for iPhoneSimulator
mkdir -p $LIB_SRC/iphonesim-build
cd $LIB_SRC/iphonesim-build
# 在我的电脑编译的时候报错，我把 iPhoneSimulator${IPHONE_SDKVERSION}.sdk 替换成了 iPhoneSimulator.sdk
export CFLAGS="-O3 -arch i386 -arch x86_64 -isysroot $XCODE_ROOT/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator.sdk
-mios-simulator-version-min=${IPHONE_SDKVERSION}"
../configure --prefix=$PREFIXDIR/iphonesim-build --disable-dependency-tracking --enable-static=yes --enable-shared=no --host=i686-pc-none
make
make install
doneSection
#编译真机版本
echo Building Libjpeg for iPhone
mkdir -p $LIB_SRC/iphone-build
cd $LIB_SRC/iphone-build
# 在我的电脑编译的时候报错，我把 iPhoneOS${IPHONE_SDKVERSION}.sdk 替换成了 iPhoneOS.sdk
export CFLAGS="-O3 -arch armv7 -arch armv7s -arch arm64 -isysroot $XCODE_ROOT/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk -mios-version-min=${IPHONE_SDKVERSION}"
../configure --host=arm-apple-darwin --prefix=$PREFIXDIR/iphone-build --disable-dependency-tracking --enable-static=yes --enable-shared=no
make
make install
doneSection
}
#===============================================================================
scrunchAllLibsTogetherInOneLibPerPlatform()
{
cd $PREFIXDIR
# iOS Device
mkdir -p $IOSBUILDDIR/armv7
mkdir -p $IOSBUILDDIR/armv7s
mkdir -p $IOSBUILDDIR/arm64
# iOS Simulator
mkdir -p $IOSBUILDDIR/i386
mkdir -p $IOSBUILDDIR/x86_64
echo Splitting all existing fat binaries...
$ARM_DEV_CMD lipo "iphone-build/lib/libjpeg.a" -thin armv7 -o $IOSBUILDDIR/armv7/libjpeg.a
$ARM_DEV_CMD lipo "iphone-build/lib/libjpeg.a" -thin armv7s -o $IOSBUILDDIR/armv7s/libjpeg.a
$ARM_DEV_CMD lipo "iphone-build/lib/libjpeg.a" -thin arm64 -o $IOSBUILDDIR/arm64/libjpeg.a
# 因为我的项目不支持模拟器，所以我把模拟器相关的代码注释掉了，需要的可以打开
$SIM_DEV_CMD lipo "iphonesim-build/lib/libjpeg.a" -thin i386 -o $IOSBUILDDIR/i386/libjpeg.a
$SIM_DEV_CMD lipo "iphonesim-build/lib/libjpeg.a" -thin x86_64 -o $IOSBUILDDIR/x86_64/libjpeg.a
}
#===============================================================================
# framework编译报错，因为我不需要framework版本，所以没有做研究，有解决这个问题的麻烦告诉我下。
buildFramework()
{
: ${1:?}
FRAMEWORKDIR=$1
BUILDDIR=$2
VERSION_TYPE=Alpha
FRAMEWORK_NAME=libjpeg
FRAMEWORK_VERSION=A
FRAMEWORK_CURRENT_VERSION=$LIB_VERSION
FRAMEWORK_COMPATIBILITY_VERSION=$LIB_VERSION
FRAMEWORK_BUNDLE=$FRAMEWORKDIR/$FRAMEWORK_NAME.framework
echo "Framework: Building $FRAMEWORK_BUNDLE from $BUILDDIR..."
rm -rf $FRAMEWORK_BUNDLE
echo "Framework: Setting up directories..."
mkdir -p $FRAMEWORK_BUNDLE
mkdir -p $FRAMEWORK_BUNDLE/Versions
mkdir -p $FRAMEWORK_BUNDLE/Versions/$FRAMEWORK_VERSION
mkdir -p $FRAMEWORK_BUNDLE/Versions/$FRAMEWORK_VERSION/Resources
mkdir -p $FRAMEWORK_BUNDLE/Versions/$FRAMEWORK_VERSION/Headers
mkdir -p $FRAMEWORK_BUNDLE/Versions/$FRAMEWORK_VERSION/Documentation
echo "Framework: Creating symlinks..."
ln -s $FRAMEWORK_VERSION $FRAMEWORK_BUNDLE/Versions/Current
ln -s Versions/Current/Headers $FRAMEWORK_BUNDLE/Headers
ln -s Versions/Current/Resources $FRAMEWORK_BUNDLE/Resources
ln -s Versions/Current/Documentation $FRAMEWORK_BUNDLE/Documentation
ln -s Versions/Current/$FRAMEWORK_NAME $FRAMEWORK_BUNDLE/$FRAMEWORK_NAME
FRAMEWORK_INSTALL_NAME=$FRAMEWORK_BUNDLE/Versions/$FRAMEWORK_VERSION/$FRAMEWORK_NAME
echo "Lipoing library into $FRAMEWORK_INSTALL_NAME..."
$ARM_DEV_CMD lipo -create $BUILDDIR/*/libjpeg.a -o "$FRAMEWORK_INSTALL_NAME" || abort "Lipo $1 failed"
echo "Framework: Copying includes..."
cp -r $PREFIXDIR/include/libjpeg/* $FRAMEWORK_BUNDLE/Headers/
echo "Framework: Creating plist..."
cat > $FRAMEWORK_BUNDLE/Resources/Info.plist <
CFBundleDevelopmentRegion
English
CFBundleExecutable
${FRAMEWORK_NAME}
CFBundleIdentifier
org.libjpeg
CFBundleInfoDictionaryVersion
6.0
CFBundlePackageType
FMWK
CFBundleSignature
????
CFBundleVersion
${FRAMEWORK_CURRENT_VERSION}
EOF
doneSection
}
#===============================================================================
# Execution starts here
#===============================================================================
mkdir -p $IOSBUILDDIR
# cleanEverythingReadyToStart #may want to comment if repeatedly running during dev
echo "LIB_VERSION: $LIB_VERSION"
echo "LIB_SRC: $LIB_SRC"
echo "IOSBUILDDIR: $IOSBUILDDIR"
echo "PREFIXDIR: $PREFIXDIR"
echo "IOSFRAMEWORKDIR: $IOSFRAMEWORKDIR"
echo "IPHONE_SDKVERSION: $IPHONE_SDKVERSION"
echo "XCODE_ROOT: $XCODE_ROOT"
echo
downloadLibjpeg
unpackLibjpeg
buildLibjpegForIPhoneOS
scrunchAllLibsTogetherInOneLibPerPlatform
buildFramework $IOSFRAMEWORKDIR $IOSBUILDDIR
echo "Completed successfully"
#===============================================================================
另：github上我上传了libjpeg.a 8.0版本和9.0版本，有需要的小伙伴可以直接去仓库下载，免去自己编译的烦恼。
github地址：https://github.com/ayangcool/leo_libjpeg
opencv2.framework下载地址：https://pan.baidu.com/s/1UgseS-QTbhx4JUOwLt89Ig
参考文章：编译ios平台下的libjpeg静态库.a文件
https://blog.csdn.net/zhangkai19890929/article/details/85598493