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ZIP files

Version 3.16 adds support for viewing the contents of ZIP files.

As always, Disk Decipher will only download/decrypt those parts of the ZIP file that are needed to serve your requests. This enables you to access big ZIP files efficiently.

The initial implementation will support the most common ZIP file options. This page lists both the supported options and the limitations.

Disk Decipher will allow you to open a ZIP file within a ZIP file (recursively).

Be aware that if a ZIP file is stored compressed inside another ZIP file, performance will suffer when reading from the child ZIP file, since compressed files do not allow seek operations. In this case the child ZIP file needs to be read from the start up to the requested part(s).

Supported options

  • Compression methods: Zlib (deflate), XZ
  • ZIP64 (ZIP files larger than 4 GB)
  • Password protection: standard ZipCrypto (weak) and WinZIP AES encryption (strong)

Limitations

  • Read-only, you cannot make changes to the ZIP file even if it is stored in a writable container
  • BZIP2, LZMA, and ZSTD compression methods are not supported
  • Streaming audio/video files within a ZIP file will perform badly, since the compressed stream does not allow seek operations.

Please let me know if any of the limitations above are important for you to get lifted.

Error codes

In case an error occurs while reading a ZIP file, Disk Decipher will show an error code. The errors are returned by the minizip-ng library, you can find the meaning of the error codes in the minizip-ng documentation.

If you feel the reported error is a bug, please report it to me. If possible, include a small container exhibiting the issue.