CRC -> specific blocks for par2-?

[aculaone]

Hello Community!

I sometimes have problems with CRC-Errors and corrupted downloads.
This sucks especially with large downloads, because I have to download them over and over again and it mostly doesn't even help!

I've read a German topic with the same problem: https://www.altbinz.net/forum/german-(deutsch)/crc-fehler-korrigierbar/
In there someone suggested: "Identify missing blocks!"

I tried to use several recommended par2-correction-apps, e.g. QuickPar.
It says there for my latest download: "2116 blocks missing".

How do I do identify missing blocks?
And once I've done that, how do I re-download those specific blocks?
And when I've done that, is it easy to recombine the missing blocks?

Thanks for your help!!
AculaOne

[cr4zyfr4g]

Alt.binz will do all this for you if you set it up correctly.

https://www.altbinz.net/wiki/Quick_Start_Guide#Set_up_download_processing_options

The Screenshots in the Link above are not accurate but will show you what to set some options to.

[aculaone]

Thank you!
But I still have no clue on how to work with my problem...

I've watched the recommendations in the wiki, but it doesn't make sense to me...

For instance: if I check "import par2 as paused" as it is recommended, it won't download them. Am I right?
And if it doesn't download the par2 files, how is it supposed to correct the missing blocks?

As it is now, it doesn't even correct the corrupted files if I DO download all par2 files!

I'm confused...

[cr4zyfr4g]

with the above settings, alt.binz will only download the small par2 file to check the files.
If there are any errors or missing blocks it will automatically unpause just as much par2 files to repair those errors/blocks.

In your case however the download is most likely too incomplete to repair.
Reasons might be:
- files are older than your providers retention time
- files are incomplete on the usenet server
- your pc has hardware problems and files become corrupt during transfer, decoding or storage (unlikely though)

[aculaone]

So if errors occur, that means the automatic repair function of alt.binz did not work - and so it's impossible to repair at all?

I filter downloads by retention time during nzb search, so that can't be the problem.
But how can I filter downloads that are incomplete from the start???

I use nzbindex.nl and nzbclub.com.
I only download files that are marked as healthy and complete and age<=700 days.

It really annoys me, because this happens quite often...

Cheers,
AculaOne

[Rdl]

Which usenet provider do you use?

Search engines showing it as complete doesn't mean that your usenet provider has it in the same condition.

[aculaone]

My provider is gebruikhet.
It says there, retention is 700+ days...

So how do I find out in what condition the binaries are with my provider?

[Hecks]

There are a few apps that will check completion for you.

Like this one (needs .NET 4.0):
http://www.zoon.dk/2011/01/25/nzb-completion-checker/

Or this one:
http://www.softsea.com/review/NZB-Download-Checker.html

But you'll probably want to just avoid all the frustration by getting a proper usenet provider. Unlimited accts are so cheap these days that cost/benefit is a no-brainer.

[aculaone]

Thank you for the apps!
I will try them out immediately!

I chose gebruikhet above all because of the anonymous payment option....

[aculaone]

So I just tested nzb_completion_checker with some of my latest incomplete downloads...
And indeed there are some parts missing on the server.

Is there any chance to get missing parts for downloads I've already made?
Or does it just mean that I have to check every nzb before downloading and no chance to get a specific one if parts are missing?

[aculaone]

So there's no way to get the missing 0,08%?
If so, it sucks.
Bigtime. :-(

[Rdl]

Well, not really. That's why par2 files are posted for.

[aculaone]

Does that mean the par2 files should normally be able to repair the missing segments?
Because in the sample download above only about 6MB are missing from 7.6GB!

[Rdl]

Yeah it should if you have enough par2 blocks.
Alt.binz should take care of it on its own if it's setup that way.

If you need help with this send a screenshots of par2 set expanded in par2 tab(if you already downloaded just import small par2 file and wait for altbinz to recheck all) and expanded files(par2 files) in queue via PM.

[davidq666]

Does that mean the par2 files should normally be able to repair the missing segments?
Because in the sample download above only about 6MB are missing from 7.6GB!

That depends entirely on the amount of par2 files posted. Usualy there are about 5-10% par2 files, so you should be able to repair it, if the the par2 files themselves are intact.