Hash :
c8358fcb
Author :
Date :
2016-12-08T14:43:59
Build: Various improvements to install/pkg system - GNUInstallDirs: any directory variable can now reference any other directory variable by including its name in angle brackets (<>). - Changed the documentation of the directory variables in BUILDING.md accordingly. This commit also includes some formatting tweaks to that section (using boldface for directory names, as is our convention.) - Changed the package scripts such that they use CMAKE_INSTALL_DATAROOTDIR rather than CMAKE_INSTALL_DATADIR. - We no longer override the install dir. defaults on Windows unless performing an official build. It may be useful, for instance, to use the GNU defaults when installing into an MSYS environment.
libjpeg-turbo is a JPEG image codec that uses SIMD instructions (MMX, SSE2, AVX2, NEON, AltiVec) to accelerate baseline JPEG compression and decompression on x86, x86-64, ARM, and PowerPC systems. On such systems, libjpeg-turbo is generally 2-6x as fast as libjpeg, all else being equal. On other types of systems, libjpeg-turbo can still outperform libjpeg by a significant amount, by virtue of its highly-optimized Huffman coding routines. In many cases, the performance of libjpeg-turbo rivals that of proprietary high-speed JPEG codecs. libjpeg-turbo implements both the traditional libjpeg API as well as the less powerful but more straightforward TurboJPEG API. libjpeg-turbo also features colorspace extensions that allow it to compress from/decompress to 32-bit and big-endian pixel buffers (RGBX, XBGR, etc.), as well as a full-featured Java interface. libjpeg-turbo was originally based on libjpeg/SIMD, an MMX-accelerated derivative of libjpeg v6b developed by Miyasaka Masaru. The TigerVNC and VirtualGL projects made numerous enhancements to the codec in 2009, and in early 2010, libjpeg-turbo spun off into an independent project, with the goal of making high-speed JPEG compression/decompression technology available to a broader range of users and developers.