par2py 0.1.2

"par2 Python Utilities"

Par2Py

MIT Licensed par2 parser / A Python framework for interacting with Par2 files

Par2 is a file format for using Reed-Solomon Coding to perform file recovery operations using "blocks" of recovery data.

#Rationale While working on a QR code based backup solution, I found myself wanting additional redundancy. Which is where Par2 comes in. Par2 is a great system with many advantages:

• Everything is in "packets", with extremely easy to decode headers.
• Packet headers are easy to find, with their "magic" values ?guaranteed? to only show up there.
• Any amount of padding (including random data) is allowed between packets.
• Provided that enough redundancy exists, a missing file can be completely reconstructed.

To increase the likelihood of file recovery I found myself needing to perform byte alignment on individual packets. There were other reasons as well, but this led to creating a par2 parser, and I decided that it would be worth it as a standalone program.

References:

• Official Specification
• Packet & Header format
• "magic" & "type"/"signature" values

Note that you can recover everything in the second link easily from any "vol...par2" file.

Other (similar) projects:

• par2ools by Jason Moiron