------------------
- autoconf 2.56 or later
-
- automake 1.7 or later
-
- libtool 1.4 or later
* If using Xcode 4.3 or later on OS X, autoconf and automake are no longer
provided. The easiest way to obtain them is from
easily build and install NASM from a source RPM by downloading one of the
SRPMs from
- http://www.nasm.us/pub/nasm/releasebuilds
+ <http://www.nasm.us/pub/nasm/releasebuilds>
and executing the following as root:
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
+ 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.
+ <http://www.java.com>.
Out-of-Tree Builds
This will generate the following files under .libs/:
-**libjpeg.a**
+**libjpeg.a**
Static link library for the libjpeg API
-**libjpeg.so.{version}** (Linux, Unix)
-**libjpeg.{version}.dylib** (OS X)
-**cygjpeg-{version}.dll** (Cygwin)
+**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)
+**libjpeg.so** (Linux, Unix)
+**libjpeg.dylib** (OS X)
Development symlink for the libjpeg API
-**libjpeg.dll.a** (Cygwin)
+**libjpeg.dll.a** (Cygwin)
Import library for the libjpeg API
-**libturbojpeg.a**
+**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)
+**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)
+**libturbojpeg.so** (Linux, Unix)
+**libturbojpeg.dylib** (OS X)
Development symlink for the TurboJPEG API
-**libturbojpeg.dll.a** (Cygwin)
+**libturbojpeg.dll.a** (Cygwin)
Import library for the TurboJPEG API
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)*
+ *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"
IOS_CFLAGS="-march=armv7 -mcpu=cortex-a8 -mtune=cortex-a8 -mfpu=neon"
- *ARMv7s (code will run on iPhone 5/iPad 4th Generation and newer)*
+ *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"
### Building libjpeg-turbo for Android
-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.
+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}
- 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:
-
- http://msdn.microsoft.com/en-us/windows/bb980924.aspx
-
+ installing the
+ [Windows SDK](http://msdn.microsoft.com/en-us/windows/bb980924.aspx).
The Windows SDK includes both 32-bit and 64-bit Visual C++ compilers and
everything necessary to build libjpeg-turbo.
- * You can also use Microsoft Visual Studio Express Edition, which is a free
- download. (NOTE: versions prior to 2012 can only be used to build 32-bit
- code.)
+ * You can also use Microsoft Visual Studio Express/Community Edition, which
+ is a free download. (NOTE: versions prior to 2012 can only be used to
+ build 32-bit code.)
* If you intend to build libjpeg-turbo from the command line, then add the
appropriate compiler and SDK directories to the `INCLUDE`, `LIB`, and
`PATH` environment variables. This is generally accomplished by
- MinGW
- MinGW-builds (http://sourceforge.net/projects/mingwbuilds/) or
- tdm-gcc (http://tdm-gcc.tdragon.net/) recommended if building on a Windows
+ [MinGW-builds](http://sourceforge.net/projects/mingwbuilds/) or
+ [tdm-gcc](http://tdm-gcc.tdragon.net/) 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.
a 64-bit build)
- If building the TurboJPEG Java wrapper, JDK 1.5 or later is required. This
- can be downloaded from http://www.java.com.
+ can be downloaded from <http://www.java.com>.
Out-of-Tree Builds
The following files will be generated under *{build_directory}*:
-**jpeg-static.lib**
+**jpeg-static.lib**
Static link library for the libjpeg API
-**sharedlib/jpeg{version}.dll**
+**sharedlib/jpeg{version}.dll**
DLL for the libjpeg API
-**sharedlib/jpeg.lib**
+**sharedlib/jpeg.lib**
Import library for the libjpeg API
-**turbojpeg-static.lib**
+**turbojpeg-static.lib**
Static link library for the TurboJPEG API
-**turbojpeg.dll**
+**turbojpeg.dll**
DLL for the TurboJPEG API
-**turbojpeg.lib**
+**turbojpeg.lib**
Import library for the TurboJPEG API
*{version}* is 62, 7, or 8, depending on whether libjpeg v6b (default), v7, or
This will generate the following files under *{build_directory}*:
-**{configuration}/jpeg-static.lib**
+**{configuration}/jpeg-static.lib**
Static link library for the libjpeg API
-**sharedlib/{configuration}/jpeg{version}.dll**
+**sharedlib/{configuration}/jpeg{version}.dll**
DLL for the libjpeg API
-**sharedlib/{configuration}/jpeg.lib**
+**sharedlib/{configuration}/jpeg.lib**
Import library for the libjpeg API
-**{configuration}/turbojpeg-static.lib**
+**{configuration}/turbojpeg-static.lib**
Static link library for the TurboJPEG API
-**{configuration}/turbojpeg.dll**
+**{configuration}/turbojpeg.dll**
DLL for the TurboJPEG API
-**{configuration}/turbojpeg.lib**
+**{configuration}/turbojpeg.lib**
Import library for the TurboJPEG API
*{configuration}* is Debug, Release, RelWithDebInfo, or MinSizeRel, depending
This will generate the following files under *{build_directory}*:
-**libjpeg.a**
+**libjpeg.a**
Static link library for the libjpeg API
-**sharedlib/libjpeg-{version}.dll**
+**sharedlib/libjpeg-{version}.dll**
DLL for the libjpeg API
-**sharedlib/libjpeg.dll.a**
+**sharedlib/libjpeg.dll.a**
Import library for the libjpeg API
-**libturbojpeg.a**
+**libturbojpeg.a**
Static link library for the TurboJPEG API
-**libturbojpeg.dll**
+**libturbojpeg.dll**
DLL for the TurboJPEG API
-**libturbojpeg.dll.a**
+**libturbojpeg.dll.a**
Import library for the TurboJPEG API
*{version}* is 62, 7, or 8, depending on whether libjpeg v6b (default), v7, or
libjpeg-turbo includes two APIs that can be used to compress and decompress
JPEG images:
-- **TurboJPEG API**
+- **TurboJPEG API**
This API provides an easy-to-use interface for compressing and decompressing
JPEG images in memory. It also provides some functionality that would not be
straightforward to achieve using the underlying libjpeg API, such as
transforms on an image. The Java interface for libjpeg-turbo is written on
top of the TurboJPEG API.
-- **libjpeg API**
+- **libjpeg API**
This is the de facto industry-standard API for compressing and decompressing
JPEG images. It is more difficult to use than the TurboJPEG API but also
more powerful. The libjpeg API implementation in libjpeg-turbo is both
#### Fully supported
-- **libjpeg: IDCT scaling extensions in decompressor**
+- **libjpeg: IDCT scaling extensions in decompressor**
libjpeg-turbo supports IDCT scaling with scaling factors of 1/8, 1/4, 3/8,
1/2, 5/8, 3/4, 7/8, 9/8, 5/4, 11/8, 3/2, 13/8, 7/4, 15/8, and 2/1 (only 1/4
and 1/2 are SIMD-accelerated.)
- **libjpeg: Arithmetic coding**
-- **libjpeg: In-memory source and destination managers**
+- **libjpeg: In-memory source and destination managers**
See notes below.
-- **cjpeg: Separate quality settings for luminance and chrominance**
+- **cjpeg: Separate quality settings for luminance and chrominance**
Note that the libpjeg v7+ API was extended to accommodate this feature only
for convenience purposes. It has always been possible to implement this
feature with libjpeg v6b (see rdswitch.c for an example.)
NOTE: As of this writing, extensive research has been conducted into the
usefulness of DCT scaling as a means of data reduction and SmartScale as a
means of quality improvement. The reader is invited to peruse the research at
-http://www.libjpeg-turbo.org/About/SmartScale and draw his/her own conclusions,
+<http://www.libjpeg-turbo.org/About/SmartScale> and draw his/her own conclusions,
but it is the general belief of our project that these features have not
demonstrated sufficient usefulness to justify inclusion in libjpeg-turbo.
-- **libjpeg: DCT scaling in compressor**
+- **libjpeg: DCT scaling in compressor**
`cinfo.scale_num` and `cinfo.scale_denom` are silently ignored.
There is no technical reason why DCT scaling could not be supported when
emulating the libjpeg v7+ API/ABI, but without the SmartScale extension (see
below), only scaling factors of 1/2, 8/15, 4/7, 8/13, 2/3, 8/11, 4/5, and
8/9 would be available, which is of limited usefulness.
-- **libjpeg: SmartScale**
+- **libjpeg: SmartScale**
`cinfo.block_size` is silently ignored.
SmartScale is an extension to the JPEG format that allows for DCT block
sizes other than 8x8. Providing support for this new format would be
interest in providing this feature would be as a means of supporting
additional DCT scaling factors.
-- **libjpeg: Fancy downsampling in compressor**
+- **libjpeg: Fancy downsampling in compressor**
`cinfo.do_fancy_downsampling` is silently ignored.
This requires the DCT scaling feature, which is not supported.
-- **jpegtran: Scaling**
+- **jpegtran: Scaling**
This requires both the DCT scaling and SmartScale features, which are not
supported.
-- **Lossless RGB JPEG files**
+- **Lossless RGB JPEG files**
This requires the SmartScale feature, which is not supported.
### What About libjpeg v9?
projects / libjpeg-turbo / commitdiff