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Hash : 6530203f
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Date : 2016-12-09T10:21:29
Build: More GNUInstallDirs improvements These improvements enable build systems to use GNUInstallDirs to define custom directory variables. - The set_dir() macro was renamed to GNUInstallDirs_set_install_dir(), in keeping with the module's established macro naming convention. - Rather than detecting whether the prefix has changed, the new GNUInstallDirs_set_install_dir() macro instead examines whether the default for the variable in question has changed. This allows for more flexibility, since build systems may decide to change the defaults based on factors other than the prefix. It also enables the macro to work properly outside of the module. - The module now performs directory variable substitution within the body of GNUInstallDirs_get_absolute_install_dir(). - The JAVADIR variable is no longer included in GNUInstallDirs. That directory is not part of the GNU spec, and it turns out that various operating systems use different conventions for the location of Java classes. Instead, the variable is now implemented in our build system as a demonstration of the aforementioned GNUInstallDirs enhancements.
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README
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TurboJPEG Java Wrapper ====================== The TurboJPEG shared library can optionally be built with a Java Native Interface wrapper, which allows the library to be loaded and used directly from Java applications. The Java front end for this is defined in several classes located under org/libjpegturbo/turbojpeg. The source code for these Java classes is licensed under a BSD-style license, so the files can be incorporated directly into both open source and proprietary projects without restriction. A Java archive (JAR) file containing these classes is also shipped with the "official" distribution packages of libjpeg-turbo. TJExample.java, which should also be located in the same directory as this README file, demonstrates how to use the TurboJPEG Java API to compress and decompress JPEG images in memory. Performance Pitfalls -------------------- The TurboJPEG Java API defines several convenience methods that can allocate image buffers or instantiate classes to hold the result of compress, decompress, or transform operations. However, if you use these methods, then be mindful of the amount of new data you are creating on the heap. It may be necessary to manually invoke the garbage collector to prevent heap exhaustion or to prevent performance degradation. Background garbage collection can kill performance, particularly in a multi-threaded environment (Java pauses all threads when the GC runs.) The TurboJPEG Java API always gives you the option of pre-allocating your own source and destination buffers, which allows you to re-use those buffers for compressing/decompressing multiple images. If the image sequence you are compressing or decompressing consists of images of the same size, then pre-allocating the buffers is recommended. Installation Directory ---------------------- The TurboJPEG Java Wrapper will look for the TurboJPEG JNI library (libturbojpeg.so, libturbojpeg.jnilib, or turbojpeg.dll) in the system library paths or in any paths specified in LD_LIBRARY_PATH (Un*x), DYLD_LIBRARY_PATH (Mac), or PATH (Windows.) Failing this, on Un*x and Mac systems, the wrapper will look for the JNI library under the library directory configured when libjpeg-turbo was built. If that library directory is /opt/libjpeg-turbo/lib32, then /opt/libjpeg-turbo/lib64 is also searched, and vice versa. If you installed the JNI library into another directory, then you will need to pass an argument of -Djava.library.path={path_to_JNI_library} to java, or manipulate LD_LIBRARY_PATH, DYLD_LIBRARY_PATH, or PATH to include the directory containing the JNI library.