Changing scaling corrupts file

[Collin Poczatek]

To reproduce (maybe)
- open file
- change scaling under rendering options
- click "save to file"
- close file
- reopen file

This generates a "broken uvf / bad header checksum" error.
My environment is openSUSE 11.1 (x86_64), building IV3D from source, last tried with rev 1536 from the svn.

It appears to be axis independent, and file independent. Tested on hand16.uvf, c60.uvf, and random .nrrd and QVis data.

[Tom Fogal (tfogal)]

I cannot reproduce on x86_64 Debian stable.

However, if I execute the task repeatedly, ImageVis3D will crash in rare cases. The crash appears to occur in UVF's GetBitWidth function, as it tries to access a vector; maybe an index out of range or something.

I have only been able to get the crash to occur in a release build, as of yet. This sounds like memory corruption... I will try with valgrind.

[Tom Fogal (tfogal)]

Attaching the backtrace when I saw one of those crashes.

This happened *during* a 'save to file' operation. It appears like we get a Qt event to render *while* the file is being written. I wouldn't doubt that something or other gets corrupted because of that. We should probably disable render events while we're performing this operation.

[Jens Krüger (jens-sci)]

please verify that this issue is fixed now

[Collin Poczatek (collin-poczatek)]

Looks fixed. Tested on c60.uvf and some QVis data. Added bonus file open/save appears to be faster?

[Jens Krüger (jens-sci)]

great,

well, I haven't done anything specifically to make the load/save faster but I added a progress dialog on load and fixing your bug meant that I prevented IV3D from accessing the data while it is being written. The former dialog may make it seem faster because you now get visual feedback, while the later may also speed up things as a side effect. Anyways, good to hear that the bug seems fixed.

Cheers
   Jens

Am 17.08.2010 um 16:49 schrieb Collin Poczatek:

> Looks fixed. Tested on c60.uvf and some QVis data. Added bonus file
> open/save appears to be faster?
>
> --
> Changing scaling corrupts file
> https://bugs.launchpad.net/bugs/618879
> You received this bug notification because you are a direct subscriber
> of the bug.
>
> Status in ImageVis3D, an out-of-core desktop volume renderer: Fix Committed
>
> Bug description:
> To reproduce (maybe)
> - open file
> - change scaling under rendering options
> - click "save to file"
> - close file
> - reopen file
>
> This generates a "broken uvf / bad header checksum" error.
> My environment is openSUSE 11.1 (x86_64), building IV3D from source, last tried with rev 1536 from the svn.
>
> It appears to be axis independent, and file independent. Tested on hand16.uvf, c60.uvf, and random .nrrd and QVis data.
>
> To unsubscribe from this bug, go to:
> https://bugs.launchpad.net/imagevis3d/+bug/618879/+subscribe