Support zstd compression method 93 in zip archives
Posted: 2022-12-30, 16:01 UTC
ZIP format had officially allocated compression method ID for Zstandard few years ago. It would be nice to support it in total commander's internal zip packer/unpacker.
I was even looking whether it would be possible to implement support myself as a plugin (or if there is any other plugin already doing it), but I was not able to find how. Seems like wcx plugin API doesn't really have a way to expose implementations of additional compression methods for use by internal zip packer. There is a plugin with zstd support, but it works with individual files and doesn't help with zip archives having zstd-compressed content.
So, alternatively, if there is no desire to support zstd compression method out of the box - I would appreciate some guidance on supporting it as a plugin.
For reference, zstd's ID is 93 according to APPNOTE.txt: https://pkware.cachefly.net/webdocs/casestudies/APPNOTE.TXT
Winzip claims its support since version 24 (released in 2019): https://www.winzip.com/en/support/compression-methods/
7-Zip-ZS has support for it as well. Although, from personal experience I can say there are some bugs in its zip handling and adding/removing files to existing files.
I was even looking whether it would be possible to implement support myself as a plugin (or if there is any other plugin already doing it), but I was not able to find how. Seems like wcx plugin API doesn't really have a way to expose implementations of additional compression methods for use by internal zip packer. There is a plugin with zstd support, but it works with individual files and doesn't help with zip archives having zstd-compressed content.
So, alternatively, if there is no desire to support zstd compression method out of the box - I would appreciate some guidance on supporting it as a plugin.
For reference, zstd's ID is 93 according to APPNOTE.txt: https://pkware.cachefly.net/webdocs/casestudies/APPNOTE.TXT
Winzip claims its support since version 24 (released in 2019): https://www.winzip.com/en/support/compression-methods/
7-Zip-ZS has support for it as well. Although, from personal experience I can say there are some bugs in its zip handling and adding/removing files to existing files.