Download MultiPar 1.3.1.9

MultiPar is an open source program that allows files and associated archive files to be checked for corruption. If necessary, it can reconstruct the data. This is used, among other things, for exchanging files via Usenet, since these are split into different parts and not all parts are available on all Usenet servers. MultiPar 1.3.1.9 was released a few days ago and the release notes for that release can be found below.

MultiPar version 1.3.1.9

This is the final release of v1.3.1 tree. There would be no serious problem. While I fixed some rare bugs and improved a bit, it’s hard to test all possible cases. When you see a bug, odd incident, or strange behavior, please let me know. I will fix as possible as I can.

I tested verification of multiple source files on my new PC. From the result, I set max number of threads for NVMe SSD to 4 threads, when CPU has 6 or more logical cores. This will improve speed at verifying complete source files. (It doesn’t affect for PAR files nor damaged files.)
SATA SSD : It will verify max 2 files at once.
NVMe SSD : It will verify max 3 or 4 files at once.

When many input file slices are same, their checksums become same, too. There was a bug in my sorting function. Nobody found the error for over than 10 years, and I solved this problem at last. thanks NilEinne for reporting the very rare incident.

When a file includes duplicated data, it’s difficult to find slices in proper position. In old versions, it might ignore overlap of slices for speed. Then, it happens to fail finding some slices. I implemented more complex method, and it will work well in most cases. thanks swarup459 for bug report, offering samples, and many tests.

It’s possible to add PAR2 recovery record to a ZIP file. When I wrote the instructions ago, 4 GB over ZIP file was not common so much. Because recent Windows OS supports ZIP64 format, I updated the text for compatibility. You may read the “Add recovery record” page of MultiPar’s Help documents. Or, you may read the article on my website. Now, MultiPar supports large ZIP file with ZIP64 format. thanks Dwaine Gonyier for notifying the potential problem.

Installer update

• Inno Setup was updated from v6.1.2 to v6.2.0.

GUI update

• Change
  • Clickable link to access author’s page becomes SSL.
  • Appending recovery record supports 2 GB over file size.

PAR2 client update

• Change

  • When source files are on NVMe SSD, verification may become faster.
  • Appending recovery record supports ZIP64 format.

• Improvement

  • Simple verification will find a short slice in a tiny file.

• bug fix

  • A stack overflow problem in quick sort function was removed.
  • A bug of searching slices in a file with repeated content was fixed.

• Inno Setup was updated from v6.1.2 to v6.2.0.

GUI update

• Change
  • Clickable link to access author’s page becomes SSL.
  • Appending recovery record supports 2 GB over file size.

PAR2 client update

• Change

  • When source files are on NVMe SSD, verification may become faster.
  • Appending recovery record supports ZIP64 format.

• Improvement

  • Simple verification will find a short slice in a tiny file.

• bug fix

  • A stack overflow problem in quick sort function was removed.
  • A bug of searching slices in a file with repeated content was fixed.