61 lines
2.3 KiB
Plaintext
61 lines
2.3 KiB
Plaintext
mozjpeg (Mozilla JPEG Encoder Project)
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mozjpeg is a fork of libjpeg-turbo from Mozilla Research. Its
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goal is to reduce the size of JPEG files without reducing quality
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or compatibility with the vast majority of the world's deployed
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decoders. The idea is to reduce transfer times for JPEGs on the Web,
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thus reducing page load times.
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mozjpeg is not intended to be a general JPEG library replacement. It
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makes tradeoffs that are intended to benefit Web use cases and
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focuses solely on improving encoding. It is best used as part of a Web
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encoding workflow.
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In essence, libjpeg-turbo (as shipped with Slackware) is optimized
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for speed of encoding/decoding, while mozjpeg is optimized for
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encoding smaller file sizes (at the expense of speed). mozjpeg will
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not interfere with Slackware's libjpeg-turbo package, as it installs
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to /opt/mozjpeg/.
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mozjpeg supports multiple versions of the libjpeg API. By default,
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version 6b is built. If you need compatibility with libjpeg 7 or 8,
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set API=7 or API=8 in the script's environment.
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Usage
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-----
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To run the binaries, either call them by their full paths, e.g:
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$ /opt/mozjpeg/bin/cjpeg
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...or else:
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$ source /etc/profile.d/mozjpeg.sh
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...to temporarily make mozjpeg the default, in the current shell.
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Running e.g. "cjpeg" will now run the mozjpeg one. If you wanted to
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do this permanently for all users (not recommended), you could:
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# chmod +x /etc/profile.d/mozjpeg.sh
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...then log out and back in. The profile script isn't executable by
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default, to avoid surprises.
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Development
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-----------
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To compile & link with the mozjpeg libraries, use -I/opt/mozjpeg/include
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and -L/opt/mozjpeg/lib (or lib64). You might also want -static, or
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else -Wl,-rpath,/opt/mozjpeg/lib (or lib64). Starting with version 3.2,
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there's also pkg-config support for mozjpeg. If you source the profile
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script, software that uses pkg-config should find and link with the
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mozjpeg libraries automatically.
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Java Support
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------------
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Optionally, mozjpeg can be built with Java wrapper support
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for turbojpeg. To do this, install one of: jdk, openjdk8,
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openjdk7, or openjdk6 (or possibly one of the zulu-openjdk*
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packages; untested). Then run this script with JAVA=yes in
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the environment. The Java library will be installed as
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/opt/mozjpeg/classes/turbojpeg.jar, and the docs will be in
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/usr/doc/mozjpeg-$VERSION/javadoc.
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