Add Zstandard support for zip archives and CHDs #11827
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* Fast x86-64 assembly language Huffman decoder disabled for now. * Only compression and decompression components built. * Library documentation not included.
Zstandard is not enabled by default so new CHDs will not be incompatible by default. Use zstd for regular Zstandard codec, and cdzs for Zstandard CD codec.
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The main impact this has it that it bloats the source a bit. Apart from that, it’s pretty much invisible to the user if they don’t consciously try to use it. |
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Finally, chd has added zstd support. If used properly, zstd decompression will exceed the speed of copying. |
Luigi30
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Dec 16, 2023
* 3rdparty/zstd: Added Zstandard compression library version 1.5.5. * util/unzip.cpp: Added support for Zstandard compression (method 93). * util/chdcodec.cpp: Added support for Zstandard compression. * 3rdparty/flac: Always define NDEBUG to avoid log spam.
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This seems promising, maybe we can run these CHDs in Wii soon :) |
einstein95
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to einstein95/mame
that referenced
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Mar 2, 2024
* 3rdparty/zstd: Added Zstandard compression library version 1.5.5. * util/unzip.cpp: Added support for Zstandard compression (method 93). * util/chdcodec.cpp: Added support for Zstandard compression. * 3rdparty/flac: Always define NDEBUG to avoid log spam.
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This does three things:
zstdandcdzscodecs).We occasionally get requests for Zstandard compression support (e.g. issue #7402). It gives far better decompression performance than zlib or particularly LZMA while delivering better compression ratios than zlib. This is important to people using emulators on low-end devices. CHD decompression speed affects performance of emulated software that streams from hard disk or CD, and zip decompression performance affects initial load time for emulated systems.
By default, chdman will not use Zstandard compression. This ensures that new CHDs will be backwards compatible if the user does not intentionally enable Zstandard compression.
You can create zip archives using Zstandard compression with WinZip, a fork of p7zip, and various other tools.