Show HN: Backblaze Reed-Solomon erasure codes(github.com)
github.com
Show HN: Backblaze Reed-Solomon erasure codes
https://github.com/Backblaze/JavaReedSolomon
5 comments
Reed-Solomon is also used in parity files (Parchive [1]) which were especially popular in the newsgroup/usenet days.
> parity files could be created that were then uploaded along with the original data files. If any of the data files were damaged or lost while being propagated between Usenet servers, users could download parity files and use them to reconstruct the damaged or missing files.
[1]: https://en.wikipedia.org/wiki/Parchive
> parity files could be created that were then uploaded along with the original data files. If any of the data files were damaged or lost while being propagated between Usenet servers, users could download parity files and use them to reconstruct the damaged or missing files.
[1]: https://en.wikipedia.org/wiki/Parchive
In 2000, I wrote a Java reed solomon implementation that also includes native libraries for linux-x86 and win32. I expect it to be at least 5x faster than a pure Java implementation.
http://www.bytebucket.org/onionnetworks/fec
http://www.bytebucket.org/onionnetworks/fec
I believe RS codes are used on optical media such as CDs and DVDs which allows perfect playback with a few scratches here and there. They're also used in QR codes, so even if the scan is imperfect, the data can be reconstructed correctly. In the case of QR codes, the standard allows the QR code creator to set the level of error correction, providing a wide range of of data size vs resilience to corruption choices.