autoconf 2.56 or later
automake 1.7 or later
libtool 1.4 or later
NASM or YASM (if building x86 or x86-64 SIMD extensions)
The binary RPMs released by the NASM project do not work on older Linux systems, such as Red Hat Enterprise Linux 4. On such systems, you can easily build and install NASM from a source RPM by downloading one of the SRPMs from
http://www.nasm.us/pub/nasm/releasebuilds
and executing the following as root:
ARCH=`uname -m`
rpmbuild --rebuild nasm-{version}.src.rpm
rpm -Uvh /usr/src/redhat/RPMS/$ARCH/nasm-{version}.$ARCH.rpm
NOTE: the NASM build will fail if texinfo is not installed.
GCC v4.1 (or later) or clang recommended for best performance
If building the TurboJPEG Java wrapper, JDK or OpenJDK 1.5 or later is required. Some systems, such as Solaris 10 and later and Red Hat Enterprise Linux 5 and later, have this pre-installed. On OS X 10.5 and 10.6, it will be necessary to install the Java Developer Package, which can be downloaded from http://developer.apple.com/downloads (Apple ID required.) For other systems, you can obtain the Oracle Java Development Kit from http://www.java.com.
Binary objects, libraries, and executables are generated in the same directory from which configure was executed (the “binary directory”), and this directory need not necessarily be the same as the libjpeg-turbo source directory. You can create multiple independent binary directories, in which different versions of libjpeg-turbo can be built from the same source tree using different compilers or settings. In the sections below, {build_directory} refers to the binary directory, whereas {source_directory} refers to the libjpeg-turbo source directory. For in-tree builds, these directories are the same.
The following procedure will build libjpeg-turbo on Linux, FreeBSD, Cygwin, and Solaris/x86 systems (on Solaris, this generates a 32-bit library. See below for 64-bit build instructions.)
cd {source_directory}
autoreconf -fiv
cd {build_directory}
sh {source_directory}/configure [additional configure flags]
make
NOTE: Running autoreconf in the source directory is not necessary if building libjpeg-turbo from one of the official release tarballs.
This will generate the following files under .libs/:
libjpeg.a
Static link library for the libjpeg API
libjpeg.so.{version} (Linux, Unix)
libjpeg.{version}.dylib (OS X)
cygjpeg-{version}.dll (Cygwin)
Shared library for the libjpeg API
By default, {version} is 62.1.0, 7.1.0, or 8.0.2, depending on whether libjpeg v6b (default), v7, or v8 emulation is enabled. If using Cygwin, {version} is 62, 7, or 8.
libjpeg.so (Linux, Unix)
libjpeg.dylib (OS X)
Development symlink for the libjpeg API
libjpeg.dll.a (Cygwin)
Import library for the libjpeg API
libturbojpeg.a
Static link library for the TurboJPEG API
libturbojpeg.so.0.1.0 (Linux, Unix)
libturbojpeg.0.1.0.dylib (OS X)
cygturbojpeg-0.dll (Cygwin)
Shared library for the TurboJPEG API
libturbojpeg.so (Linux, Unix)
libturbojpeg.dylib (OS X)
Development symlink for the TurboJPEG API
libturbojpeg.dll.a (Cygwin)
Import library for the TurboJPEG API
Add --with-jpeg7 to the configure command line to build a version of libjpeg-turbo that is API/ABI-compatible with libjpeg v7. Add --with-jpeg8 to the configure command to build a version of libjpeg-turbo that is API/ABI-compatible with libjpeg v8. See README.md for more information on libjpeg v7 and v8 emulation.
When using libjpeg v6b or v7 API/ABI emulation, add --without-mem-srcdst to the configure command line to build a version of libjpeg-turbo that lacks the jpeg_mem_src() and jpeg_mem_dest() functions. These functions were not part of the original libjpeg v6b and v7 APIs, so removing them ensures strict conformance with those APIs. See README.md for more information.
Since the patent on arithmetic coding has expired, this functionality has been included in this release of libjpeg-turbo. libjpeg-turbo's implementation is based on the implementation in libjpeg v8, but it works when emulating libjpeg v7 or v6b as well. The default is to enable both arithmetic encoding and decoding, but those who have philosophical objections to arithmetic coding can add --without-arith-enc or --without-arith-dec to the configure command line to disable encoding or decoding (respectively.)
Add --with-java to the configure command line to incorporate an optional Java Native Interface wrapper into the TurboJPEG shared library and build the Java front-end classes to support it. This allows the TurboJPEG shared library to be used directly from Java applications. See java/README for more details.
You can set the JAVAC, JAR, and JAVA configure variables to specify alternate commands for javac, jar, and java (respectively.) You can also set the JAVACFLAGS configure variable to specify arguments that should be passed to the Java compiler when building the front-end classes, and JNI_CFLAGS to specify arguments that should be passed to the C compiler when building the JNI wrapper. Run configure --help for more details.
If you intend to install these libraries and the associated header files, then replace ‘make’ in the instructions above with
make install prefix={base dir} libdir={library directory}
For example,
make install prefix=/usr/local libdir=/usr/local/lib64
will install the header files in /usr/local/include and the library files in /usr/local/lib64. If prefix and libdir are not specified, then the default is to install the header files in /opt/libjpeg-turbo/include and the library files in /opt/libjpeg-turbo/lib32 (32-bit) or /opt/libjpeg-turbo/lib64 (64-bit.)
NOTE: You can specify a prefix of /usr and a libdir of, for instance, /usr/lib64 to overwrite the system‘s version of libjpeg. If you do this, however, then be sure to BACK UP YOUR SYSTEM’S INSTALLATION OF LIBJPEG before overwriting it. It is recommended that you instead install libjpeg-turbo into a non-system directory and manipulate the LD_LIBRARY_PATH or create symlinks to force applications to use libjpeg-turbo instead of libjpeg. See README.md for more information.
Add
--host i686-pc-linux-gnu CFLAGS='-O3 -m32' LDFLAGS=-m32
to the configure command line.
Add
--host x86_64-apple-darwin NASM=/opt/local/bin/nasm
to the configure command line. NASM 2.07 or later from MacPorts must be installed.
Add
--host i686-apple-darwin CFLAGS='-O3 -m32' LDFLAGS=-m32
to the configure command line.
Add
--host x86_64-apple-darwin NASM=/opt/local/bin/nasm \ CFLAGS='-mmacosx-version-min=10.5 -O3' \ LDFLAGS='-mmacosx-version-min=10.5'
to the configure command line. NASM 2.07 or later from MacPorts must be installed.
Add
--host i686-apple-darwin \ CFLAGS='-mmacosx-version-min=10.5 -O3 -m32' \ LDFLAGS='-mmacosx-version-min=10.5 -m32'
to the configure command line.
Add
--host x86_64-pc-solaris CFLAGS='-O3 -m64' LDFLAGS=-m64
to the configure command line.
Add
--host i386-unknown-freebsd CC='gcc -B /usr/lib32' CFLAGS='-O3 -m32' \ LDFLAGS='-B/usr/lib32'
to the configure command line. NASM 2.07 or later from FreeBSD ports must be installed.
Add
CC=cc
to the configure command line. libjpeg-turbo will automatically be built with the maximum optimization level (-xO5) unless you override CFLAGS.
To build a 64-bit version of libjpeg-turbo using Oracle Solaris Studio, add
--host x86_64-pc-solaris CC=cc CFLAGS='-xO5 -m64' LDFLAGS=-m64
to the configure command line.
Use CMake (see recipes below)
This release of libjpeg-turbo can use ARM NEON SIMD instructions to accelerate JPEG compression/decompression by approximately 2-4x on ARMv7 and later platforms. If libjpeg-turbo is configured on an ARM Linux platform, then the build system will automatically include the NEON SIMD routines, if they are supported. Build instructions for other ARM-based platforms follow.
iOS platforms, such as the iPhone and iPad, use ARM processors, some of which support NEON instructions. Additional steps are required in order to build libjpeg-turbo for these platforms.
PATH.Set the following shell variables for simplicity:
Xcode 4.2 and earlier
IOS_PLATFORMDIR=/Developer/Platforms/iPhoneOS.platform`
Xcode 4.3 and later
IOS_PLATFORMDIR=/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform
All Xcode versions
IOS_SYSROOT=$IOS_PLATFORMDIR/Developer/SDKs/iPhoneOS*.sdk IOS_GCC=$IOS_PLATFORMDIR/Developer/usr/bin/arm-apple-darwin10-llvm-gcc-4.2
ARMv6 (code will run on all iOS devices, not SIMD-accelerated)
[NOTE: Requires Xcode 4.4.x or earlier]
IOS_CFLAGS="-march=armv6 -mcpu=arm1176jzf-s -mfpu=vfp"
ARMv7 (code will run on iPhone 3GS-4S/iPad 1st-3rd Generation and newer)
IOS_CFLAGS="-march=armv7 -mcpu=cortex-a8 -mtune=cortex-a8 -mfpu=neon"
ARMv7s (code will run on iPhone 5/iPad 4th Generation and newer)
[NOTE: Requires Xcode 4.5 or later]
IOS_CFLAGS="-march=armv7s -mcpu=swift -mtune=swift -mfpu=neon"
Follow the procedure under “Building libjpeg-turbo” above, adding
--host arm-apple-darwin10 \ CC="$IOS_GCC" LD="$IOS_GCC" \ CFLAGS="-mfloat-abi=softfp -isysroot $IOS_SYSROOT -O3 $IOS_CFLAGS" \ LDFLAGS="-mfloat-abi=softfp -isysroot $IOS_SYSROOT $IOS_CFLAGS"
to the configure command line.
Set the following shell variables for simplicity:
IOS_PLATFORMDIR=/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform IOS_SYSROOT=$IOS_PLATFORMDIR/Developer/SDKs/iPhoneOS*.sdk IOS_GCC=/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang
ARMv7 (code will run on iPhone 3GS-4S/iPad 1st-3rd Generation and newer)
IOS_CFLAGS="-arch armv7"
ARMv7s (code will run on iPhone 5/iPad 4th Generation and newer)
IOS_CFLAGS="-arch armv7s"
Follow the procedure under “Building libjpeg-turbo” above, adding
--host arm-apple-darwin10 \ CC="$IOS_GCC" LD="$IOS_GCC" \ CFLAGS="-mfloat-abi=softfp -isysroot $IOS_SYSROOT -O3 $IOS_CFLAGS" \ LDFLAGS="-mfloat-abi=softfp -isysroot $IOS_SYSROOT $IOS_CFLAGS" \ CCASFLAGS="-no-integrated-as $IOS_CFLAGS"
to the configure command line.
Code will run on iPhone 5S/iPad Mini 2/iPad Air and newer.
Set the following shell variables for simplicity:
IOS_PLATFORMDIR=/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform IOS_SYSROOT=$IOS_PLATFORMDIR/Developer/SDKs/iPhoneOS*.sdk IOS_GCC=/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang IOS_CFLAGS="-arch arm64"
Follow the procedure under “Building libjpeg-turbo” above, adding
--host aarch64-apple-darwin \ CC="$IOS_GCC" LD="$IOS_GCC" \ CFLAGS="-isysroot $IOS_SYSROOT -O3 $IOS_CFLAGS" \ LDFLAGS="-isysroot $IOS_SYSROOT $IOS_CFLAGS"
to the configure command line.
NOTE: You can also add -miphoneos-version-min={version} to $IOS_CFLAGS above in order to support older versions of iOS than the default version supported by the SDK.
Once built, lipo can be used to combine the ARMv6, v7, v7s, and/or v8 variants into a universal library.
Building libjpeg-turbo for Android platforms requires the {Android NDK}(https://developer.android.com/tools/sdk/ndk) and autotools. 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/ndk}
BUILD_PLATFORM={the platform name for the NDK package you installed--
for example, "windows-x86" or "linux-x86_64" or "darwin-x86_64"}
TOOLCHAIN_VERSION={"4.8", "4.9", "clang3.5", etc. This corresponds to a
toolchain directory under ${NDK_PATH}/toolchains/.}
ANDROID_VERSION={The minimum version of Android to support-- for example,
"16", "19", etc. "21" or later is required for a 64-bit build.}
# 32-bit ARMv7 build
HOST=arm-linux-androideabi
SYSROOT=${NDK_PATH}/platforms/android-${ANDROID_VERSION}/arch-arm
ANDROID_CFLAGS="-march=armv7-a -mfloat-abi=softfp -fprefetch-loop-arrays \
--sysroot=${SYSROOT}"
# 64-bit ARMv8 build
HOST=aarch64-linux-android
SYSROOT=${NDK_PATH}/platforms/android-${ANDROID_VERSION}/arch-arm64
ANDROID_CFLAGS="--sysroot=${SYSROOT}"
TOOLCHAIN=${NDK_PATH}/toolchains/${HOST}-${TOOLCHAIN_VERSION}/prebuilt/${BUILD_PLATFORM}
ANDROID_INCLUDES="-I${SYSROOT}/usr/include -I${TOOLCHAIN}/include"
export CPP=${TOOLCHAIN}/bin/${HOST}-cpp
export AR=${TOOLCHAIN}/bin/${HOST}-ar
export AS=${TOOLCHAIN}/bin/${HOST}-as
export NM=${TOOLCHAIN}/bin/${HOST}-nm
export CC=${TOOLCHAIN}/bin/${HOST}-gcc
export LD=${TOOLCHAIN}/bin/${HOST}-ld
export RANLIB=${TOOLCHAIN}/bin/${HOST}-ranlib
export OBJDUMP=${TOOLCHAIN}/bin/${HOST}-objdump
export STRIP=${TOOLCHAIN}/bin/${HOST}-strip
cd {build_directory}
sh {source_directory}/configure --host=${HOST} \
CFLAGS="${ANDROID_INCLUDES} ${ANDROID_CFLAGS} -O3 -fPIE" \
CPPFLAGS="${ANDROID_INCLUDES} ${ANDROID_CFLAGS}" \
LDFLAGS="${ANDROID_CFLAGS} -pie" --with-simd ${1+"$@"}
make
If building for Android 4.0.x (API level < 16) or earlier, remove -fPIE from CFLAGS and -pie from LDFLAGS.
CMake v2.8.8 or later
NASM 0.98 or later (NASM 2.05 or later is required for a 64-bit build)
PATH.Microsoft Visual C++ 2005 or later
If you don't already have Visual C++, then the easiest way to get it is by installing the Windows SDK. The Windows SDK includes both 32-bit and 64-bit Visual C++ compilers and everything necessary to build libjpeg-turbo.
INCLUDE, LIB, and PATH environment variables. This is generally accomplished by executing vcvars32.bat or vcvars64.bat and SetEnv.cmd. vcvars32.bat and vcvars64.bat are part of Visual C++ and are located in the same directory as the compiler. SetEnv.cmd is part of the Windows SDK. You can pass optional arguments to SetEnv.cmd to specify a 32-bit or 64-bit build environment.... OR ...
MinGW
MinGW-builds or tdm-gcc recommended if building on a Windows machine. Both distributions install a Start Menu link that can be used to launch a command prompt with the appropriate compiler paths automatically set.
If building the TurboJPEG Java wrapper, JDK 1.5 or later is required. This can be downloaded from http://www.java.com.
Binary objects, libraries, and executables are generated in the same directory from which cmake was executed (the “binary directory”), and this directory need not necessarily be the same as the libjpeg-turbo source directory. You can create multiple independent binary directories, in which different versions of libjpeg-turbo can be built from the same source tree using different compilers or settings. In the sections below, {build_directory} refers to the binary directory, whereas {source_directory} refers to the libjpeg-turbo source directory. For in-tree builds, these directories are the same.
cd {build_directory}
cmake -G "NMake Makefiles" -DCMAKE_BUILD_TYPE=Release {source_directory}
nmake
This will build either a 32-bit or a 64-bit version of libjpeg-turbo, depending on which version of cl.exe is in the PATH.
The following files will be generated under {build_directory}:
jpeg-static.lib
Static link library for the libjpeg API
sharedlib/jpeg{version}.dll
DLL for the libjpeg API
sharedlib/jpeg.lib
Import library for the libjpeg API
turbojpeg-static.lib
Static link library for the TurboJPEG API
turbojpeg.dll
DLL for the TurboJPEG API
turbojpeg.lib
Import library for the TurboJPEG API
{version} is 62, 7, or 8, depending on whether libjpeg v6b (default), v7, or v8 emulation is enabled.
Choose the appropriate CMake generator option for your version of Visual Studio (run cmake with no arguments for a list of available generators.) For instance:
cd {build_directory}
cmake -G "Visual Studio 10" {source_directory}
NOTE: Add “Win64” to the generator name (for example, “Visual Studio 10 Win64”) to build a 64-bit version of libjpeg-turbo. Recent versions of CMake no longer document that. A separate build directory must be used for 32-bit and 64-bit builds.
You can then open ALL_BUILD.vcproj in Visual Studio and build one of the configurations in that project (“Debug”, “Release”, etc.) to generate a full build of libjpeg-turbo.
This will generate the following files under {build_directory}:
{configuration}/jpeg-static.lib
Static link library for the libjpeg API
sharedlib/{configuration}/jpeg{version}.dll
DLL for the libjpeg API
sharedlib/{configuration}/jpeg.lib
Import library for the libjpeg API
{configuration}/turbojpeg-static.lib
Static link library for the TurboJPEG API
{configuration}/turbojpeg.dll
DLL for the TurboJPEG API
{configuration}/turbojpeg.lib
Import library for the TurboJPEG API
{configuration} is Debug, Release, RelWithDebInfo, or MinSizeRel, depending on the configuration you built in the IDE, and {version} is 62, 7, or 8, depending on whether libjpeg v6b (default), v7, or v8 emulation is enabled.
NOTE: This assumes that you are building on a Windows machine. If you are cross-compiling on a Linux/Unix machine, then see “Build Recipes” below.
cd {build_directory}
cmake -G "MinGW Makefiles" {source_directory}
mingw32-make
This will generate the following files under {build_directory}:
libjpeg.a
Static link library for the libjpeg API
sharedlib/libjpeg-{version}.dll
DLL for the libjpeg API
sharedlib/libjpeg.dll.a
Import library for the libjpeg API
libturbojpeg.a
Static link library for the TurboJPEG API
libturbojpeg.dll
DLL for the TurboJPEG API
libturbojpeg.dll.a
Import library for the TurboJPEG API
{version} is 62, 7, or 8, depending on whether libjpeg v6b (default), v7, or v8 emulation is enabled.
Add -DCMAKE_BUILD_TYPE=Debug to the cmake command line. Or, if building with NMake, remove -DCMAKE_BUILD_TYPE=Release (Debug builds are the default with NMake.)
Add -DWITH_JPEG7=1 to the cmake command line to build a version of libjpeg-turbo that is API/ABI-compatible with libjpeg v7. Add -DWITH_JPEG8=1 to the cmake command line to build a version of libjpeg-turbo that is API/ABI-compatible with libjpeg v8. See README.md for more information on libjpeg v7 and v8 emulation.
When using libjpeg v6b or v7 API/ABI emulation, add -DWITH_MEM_SRCDST=0 to the cmake command line to build a version of libjpeg-turbo that lacks the jpeg_mem_src() and jpeg_mem_dest() functions. These functions were not part of the original libjpeg v6b and v7 APIs, so removing them ensures strict conformance with those APIs. See README.md for more information.
Since the patent on arithmetic coding has expired, this functionality has been included in this release of libjpeg-turbo. libjpeg-turbo's implementation is based on the implementation in libjpeg v8, but it works when emulating libjpeg v7 or v6b as well. The default is to enable both arithmetic encoding and decoding, but those who have philosophical objections to arithmetic coding can add -DWITH_ARITH_ENC=0 or -DWITH_ARITH_DEC=0 to the cmake command line to disable encoding or decoding (respectively.)
Add -DWITH_JAVA=1 to the cmake command line to incorporate an optional Java Native Interface wrapper into the TurboJPEG shared library and build the Java front-end classes to support it. This allows the TurboJPEG shared library to be used directly from Java applications. See java/README for more details.
If you are using CMake 2.8, you can set the Java_JAVAC_EXECUTABLE, Java_JAVA_EXECUTABLE, and Java_JAR_EXECUTABLE CMake variables to specify alternate commands or locations for javac, jar, and java (respectively.) You can also set the JAVACFLAGS CMake variable to specify arguments that should be passed to the Java compiler when building the front-end classes.
You can use the build system to install libjpeg-turbo into a directory of your choosing (as opposed to creating an installer.) To do this, add:
-DCMAKE_INSTALL_PREFIX={install_directory}
to the cmake command line.
For example,
cmake -G "NMake Makefiles" -DCMAKE_BUILD_TYPE=Release \
-DCMAKE_INSTALL_PREFIX=c:\libjpeg-turbo {source_directory}
nmake install
will install the header files in c:\libjpeg-turbo\include, the library files in c:\libjpeg-turbo\lib, the DLL's in c:\libjpeg-turbo\bin, and the documentation in c:\libjpeg-turbo\doc.
cd {build_directory}
CC=/usr/bin/x86_64-w64-mingw32-gcc \
cmake -G "Unix Makefiles" -DCMAKE_SYSTEM_NAME=Windows \
-DCMAKE_RC_COMPILER=/usr/bin/x86_64-w64-mingw32-windres.exe \
{source_directory}
make
This produces a 64-bit build of libjpeg-turbo that does not depend on cygwin1.dll or other Cygwin DLL's. The mingw64-x86_64-gcc-core and mingw64-x86_64-gcc-g++ packages (and their dependencies) must be installed.
cd {build_directory}
CC=/usr/bin/i686-w64-mingw32-gcc \
cmake -G "Unix Makefiles" -DCMAKE_SYSTEM_NAME=Windows \
-DCMAKE_RC_COMPILER=/usr/bin/i686-w64-mingw32-windres.exe \
{source_directory}
make
This produces a 32-bit build of libjpeg-turbo that does not depend on cygwin1.dll or other Cygwin DLL's. The mingw64-i686-gcc-core and mingw64-i686-gcc-g++ packages (and their dependencies) must be installed.
cd {build_directory}
CC={mingw_binary_path}/i686-pc-mingw32-gcc \
cmake -G "Unix Makefiles" -DCMAKE_SYSTEM_NAME=Windows \
-DCMAKE_RC_COMPILER={mingw_binary_path}/i686-pc-mingw32-windres \
-DCMAKE_AR={mingw_binary_path}/i686-pc-mingw32-ar \
-DCMAKE_RANLIB={mingw_binary_path}/i686-pc-mingw32-ranlib \
{source_directory}
make
The following commands can be used to create various types of release packages:
make rpm
Create Red Hat-style binary RPM package. Requires RPM v4 or later.
make srpm
This runs make dist to create a pristine source tarball, then creates a Red Hat-style source RPM package from the tarball. Requires RPM v4 or later.
make deb
Create Debian-style binary package. Requires dpkg.
make dmg
Create Macintosh package/disk image. This requires pkgbuild and productbuild, which are installed by default on OS X 10.7 and later and which can be obtained by installing Xcode 3.2.6 (with the “Unix Development” option) on OS X 10.6. Packages built in this manner can be installed on OS X 10.5 and later, but they must be built on OS X 10.6 or later.
make udmg [BUILDDIR32={32-bit build directory}]
On 64-bit OS X systems, this creates a Macintosh package and disk image that contains universal i386/x86-64 binaries. You should first configure a 32-bit out-of-tree build of libjpeg-turbo, then configure a 64-bit out-of-tree build, then run make udmg from the 64-bit build directory. The build system will look for the 32-bit build under {source_directory}/osxx86 by default, but you can override this by setting the BUILDDIR32 variable on the make command line as shown above.
make iosdmg [BUILDDIR32={32-bit build directory}] \
[BUILDDIRARMV6={ARMv6 build directory}] \
[BUILDDIRARMV7={ARMv7 build directory}] \
[BUILDDIRARMV7S={ARMv7s build directory}] \
[BUILDDIRARMV8={ARMv8 build directory}]
On OS X systems, this creates a Macintosh package and disk image in which the libjpeg-turbo static libraries contain ARM architectures necessary to build iOS applications. If building on an x86-64 system, the binaries will also contain the i386 architecture, as with make udmg above. You should first configure ARMv6, ARMv7, ARMv7s, and/or ARMv8 out-of-tree builds of libjpeg-turbo (see “Building libjpeg-turbo for iOS” above.) If you are building an x86-64 version of libjpeg-turbo, you should configure a 32-bit out-of-tree build as well. Next, build libjpeg-turbo as you would normally, using an out-of-tree build. When it is built, run make iosdmg from the build directory. The build system will look for the ARMv6 build under {source_directory}/iosarmv6 by default, the ARMv7 build under {source_directory}/iosarmv7 by default, the ARMv7s build under {source_directory}/iosarmv7s by default, the ARMv8 build under {source_directory}/iosarmv8 by default, and (if applicable) the 32-bit build under {source_directory}/osxx86 by default, but you can override this by setting the BUILDDIR32, BUILDDIRARMV6, BUILDDIRARMV7, BUILDDIRARMV7S, and/or BUILDDIRARMV8 variables on the make command line as shown above.
NOTE: If including an ARMv8 build in the package, then you may need to use Xcode‘s version of lipo instead of the operating system’s. To do this, pass an argument of LIPO="xcrun lipo" on the make command line.
make cygwinpkg
Build a Cygwin binary package.
If using NMake:
cd {build_directory}
nmake installer
If using MinGW:
cd {build_directory}
make installer
If using the Visual Studio IDE, build the “installer” project.
The installer package (libjpeg-turbo[-gcc][64].exe) will be located under {build_directory}. If building using the Visual Studio IDE, then the installer package will be located in a subdirectory with the same name as the configuration you built (such as {build_directory}\Debug\ or {build_directory}\Release).
Building a Windows installer requires the Nullsoft Install System (http://nsis.sourceforge.net/.) makensis.exe should be in your PATH.
The most common way to test libjpeg-turbo is by invoking make test on Unix/Linux platforms or ctest on Windows platforms, once the build has completed. This runs a series of tests to ensure that mathematical compatibility has been maintained between libjpeg-turbo and libjpeg v6b. This also invokes the TurboJPEG unit tests, which ensure that the colorspace extensions, YUV encoding, decompression scaling, and other features of the TurboJPEG C and Java APIs are working properly (and, by extension, that the equivalent features of the underlying libjpeg API are also working.)
Invoking make testclean or nmake testclean (if using NMake) or building the ‘testclean’ target (if using the Visual Studio IDE) will clean up the output images generated by make test.
On Unix/Linux platforms, more extensive tests of the TurboJPEG C and Java wrappers can be run by invoking make tjtest. These extended TurboJPEG tests essentially iterate through all of the available features of the TurboJPEG APIs that are not covered by the TurboJPEG unit tests (this includes the lossless transform options) and compare the images generated by each feature to images generated using the equivalent feature in the libjpeg API. The extended TurboJPEG tests are meant to test for regressions in the TurboJPEG wrappers, not in the underlying libjpeg API library.