It's frustrating to get only 99%
of a file from BitTorrent or Usenet.
Error
correcting
codes could help. The basic
idea of an ECC is that the file you download is 110% bigger, but if
you're missing 5% of the file you can still recover it. PC hard
drives, memory, and modems use ECCs: why not file distribution?
A popular Reed-Solomon code is RS(255,223) with 8-bit symbols. Each
codeword contains 255 code word bytes, of which 223 bytes are data and
32 bytes are parity. ...
errors in up to 16 bytes anywhere in the codeword can be automatically
corrected.
RAR
archives support ECCs via data recovery blocks, but few people use them.
There's momentum behind
PArchive, a
file format.
It
seems optimized for transferring large lists of files rather
than a single archive.
PAR usability is low but
QuickPar is OK.
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