MultiPar - file verification and redundancy

[smaragdus]

I do not think that MultiPar 1.2.9.6 is Beta:



Sometimes there are Betas followed by stable releases with the same version number (for example Phoner and PhonerLite) so what might have once been a Beta release may now be a stable release.

I compared the hashes of the files provided at the official web-site with those I downloaded from the unofficial mirror- they match. I don't have a reason to distrust the European mirror- it looks nicer, it is better organized, it offers RSS. I do not find anything fishy, malicious or tricky about the European mirror, the site is totally clean:

VirusTotal analysis - 0 / 68

[SYSTEM]

I do not think that MultiPar 1.2.9.6 is Beta:



Sometimes there are Betas followed by stable releases with the same version number (for example Phoner and PhonerLite) so what might have once been a Beta release may now be a stable release.

Note that some developers want that the final release is bit-for-bit identical to the last release candidate or beta. Such a practice avoids situations where the beta is spotless but the release has a bug.

If Mr. Yutaka Sawada follows that practice, the beta version has a final-like version number in the About dialog just so that he is able to release the exact same build as a stable release later (assuming that no bugs are found).

I would trust the website here.

[smaragdus]

MultiPar is at version 1.2.9.7. Whether it is beta or stable I cannot say. The official site states it is beta, the European mirror announces it as stable, so does Softpedia. Most likely SYSTEM is right about the betas.

I checked the two download sources:

https://www.livebusinesschat.com/smf/in ... pic=6069.0 - Official
https://multipar.eu/ - Mirror

The files are the same.

Direct Download Links for MultiPar 1.2.9.7:

Official:
Archive
Installer

Mirror:
Archive
Installer

[gezley]

I compared the hashes of the files provided at the official web-site with those I downloaded from the unofficial mirror- they match. I don't have a reason to distrust the European mirror- it looks nicer, it is better organized, it offers RSS. I do not find anything fishy, malicious or tricky about the European mirror, the site is totally clean:

smaragdus - I raised the issue not because the European mirror is suspect but rather because the developer of this software solicits donations at his website. For this reason it is unfair to promote an alternative mirror as the primary download source.

[webfork]

I sat down with Multipar to see what it could and couldn't do ...

Testing

WAV file

• I took a WAV file and created a 10% PAR file, I then cut a single second of silence out near the end. Multipar wasn't able to recover the file, I think because the audio editor (Wavosaur) modified the entire file. I think I understand what WaveShop's "bit-perfect" means.

TXT file

• I generated an 50k text document in Notepad++ with a repeating random text pattern and then deleted 3 random characters and saved it. The program was able to recover this so I went in and deleted 50 more characters and the program was still able to recover. Finally I deleted roughly a paragraph and the program was again able to pull it back.

Question

• Does anyone know why it outputs two PAR2 files? Does anyone know how to make it produce just one file?

Pros

• There's a good help file included, which is unique among programs like this.
• You can use multiple fragments of files to verify a given file, which is amazing.

Cons

• It's a little overwhelming in terms of a program. There's a lot of tools, a lot of options, and a lot of flexibility. I know only a few people who wouldn't flinch at the technical approach. Really the program leans on the fact that it has context menu options, which I don't enable for a more stealth approach.

Wishlist

• I'd change the "Open" button to "Verify/Repair"
• I'd like to see a simplified view that has drag-and-drop for a single file or a folder just provides 3 options with corresponding redundancy:
  - Protection against rare incident 10%
  - Recommended for most backups 20%
  - Have frequent errors in my transfers / backups 50%
  - Based on the available media storage size (with the current drop-down menu)
  
  (I'm pulling these numbers out of the help file. Someone who knows more about the protocol would have to determine that.)
• It would be nice (this may not be possible) to have the creation and verification interfaces include a processor priority control
• Ability to save a file that isn't 100% repaired to as close as the program is able.
• Help file elements:
  
  • The program gave an error in my process indicating I needed 2141 more blocks. I think some kind of button that would open to the help file to the "Verify and Repair" section or an additional entry on "FAQ: what does it mean when it says I need __ more blocks".
  • A "Help" button on the interface pointing to it might be worthwhile (right now it's underneath the "About" button.
  • Missing from the Help file is a set of use cases, meaning some possible reasons why you'd want to use MultiPar. Arguably it's really for sites like PortableFreeware to explain clearly, otherwise why did you download it?

[webfork]

I raised the issue not because the European mirror is suspect but rather because the developer of this software solicits donations at his website

Actually this is a weird one: the last time I checked the donation buttons pointed to the same place. Regardless, I think it should be site policy to link to the developer's site both for attribution and in case the donation system changes for some reason. I wouldn't be surprised based on ongoing bad news about Paypal.

[webfork]

1.2.9.8 is out but it looks like a minor release:

https://www.livebusinesschat.com/smf/in ... pic=6088.0

[smaragdus]

MultiPar at version 1.2.9.9, changes:

[Release note]

This is the last of v1.2.9 tree. After previous version, I fixed a rare bug only. I hope there is no noticeable problem.

[ Changes from 1.2.9.8 to 1.2.9.9 ]

PAR2 client update
Bug fix: A rare failure in finding complete slices was fixed.

and all downloads.

Direct Download Links:

Japanese ftp:
Archive
Installer

European mirror:
Archive
Installer

[webfork]

I'm happy to report that I successfully tested Multipar today. This has been on my list of things to do since it first appeared on the site.

I backed up a 20 gig file to a thumb drive, which was FAT formatted. As I don't really trust that drive fromat nor will it accept 20 gig files, I broke it up into parts with 7zip and used Multipar to create redundancy in the event of drive failure.

I set the base directory to where I'd saved all the split-up 7zip files and set the redundancy to 20% and split the PAR files into 15 meg chunks.



I then loaded up Multipar on a separate machine.

This part wasn't super obvious, but if you Click Open and then select the main PAR 2 file:



... the program will automatically start verifying:



For 23 gigs of backup files total (on a reasonably new flashdrive), it took 3:18 seconds.

There were fortunately no errors so I unzipped the file on the second system without issue. Win.

[Bok8K]

This is a problem that exists from V8 beta1: if you try to to use MUltiPAR while downloading, you get a message that files in
"!! newsleecher temporary !!" ( a subdirectory) cannot been accessed because they are owned by another process.
I'm using Multipar MultiPar1301_setup.exe. There should be an option preventing looking for files in subdirectories

[webfork]

When you say "use multipar while downloading" do you mean you run the program as a sort of verification that it's completed downloading? Or are you trying to repair a file that's come across incomplete?

Also have you tried contacting the dev about your issue?

[Bok8K]

When you say "use multipar while downloading" do you mean you run the program as a sort of verification that it's completed downloading? Or are you trying to repair a file that's come across incomplete?

Also have you tried contacting the dev about your issue?

I mean I start Multipart as soon as the first PAR file is downloaded, to completely replace the integrated Newsleecher PAR recovery which is less performant and does not allow to run a script on completion.
I left the same message on the Newsleecher forum, asking for an option to not lock subdirectories, but it has been ignored for years.
I could write an exe which will wait for the temporary file to disappear and only then launch Multipar, but that would delay the repair, Multipar loads a file as soon as it's downloaded.

[webfork]

Interesting article that talks about error correction that underlies the Par format. The headline sounds like it's taking a negative view but that's not the case.

‘Magical’ Error Correction Scheme Proved Inherently Inefficient
https://www.quantamagazine.org/magical- ... -20240109/