-
Notifications
You must be signed in to change notification settings - Fork 2k
New issue
Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.
By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.
Already on GitHub? Sign in to your account
Add Zstandard support for zip archives and CHDs #11827
Merged
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
* 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.
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. |
Finally, chd has added zstd support. If used properly, zstd decompression will exceed the speed of copying. |
Luigi30
pushed a commit
to Luigi30/mame
that referenced
this pull request
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.
This seems promising, maybe we can run these CHDs in Wii soon :) |
einstein95
pushed a commit
to einstein95/mame
that referenced
this pull request
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.
This was referenced Jun 25, 2024
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This does three things:
zstd
andcdzs
codecs).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.