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Anyone happens to know a good differential compression library for C, and okay for commercial use (no GPL, so xdelta is out of the question)? I googled around, there was zdelta, but it hasn't been updated for almost 10 years and doesn't seem to support stream decompression. Thanks in advance!

poolie
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fy_iceworld
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  • wait I thought zlib only has gzip? – fy_iceworld Jul 26 '13 at 03:17
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    which type of compression do you need? – aah134 Jul 26 '13 at 03:19
  • its good if you are compressing something that you want to send over network connection, and then uncompress back. – aah134 Jul 26 '13 at 03:21
  • differential, the algorithm `rsync` uses – fy_iceworld Jul 26 '13 at 03:22
  • I'm not following you.. I need a tool to compress a bunch of similar binaries, while gzip is okay, differential compression will save much much much more, size wise – fy_iceworld Jul 26 '13 at 03:25
  • If you place all the binaries in a single tar ball, and gzip that, what compression ratio do you get? Then, how does that compression ratio compare to what you expect to be able to get with differential compression? – jxh Jul 26 '13 at 03:28
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    GPL IS valid for commercial use. Whay do you say that it is not? May be you can have redistribution problems, but that's another problem – dAm2K Jul 26 '13 at 14:50
  • @jxh with gzip I can get no better than 5:1, but with differential compression the number goes up to two digits (lots of binaries) – fy_iceworld Jul 26 '13 at 20:56

2 Answers2

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I saw a librsync in ubuntu's repositories: https://github.com/librsync/librsync

alastairtree
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bsdiff is a better differential compressor than xdelta, and has a very liberal BSD-like license.

Mark Adler
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