Bug 217555 - "Cannot display preview" error when browsing
Summary: "Cannot display preview" error when browsing
Status: RESOLVED FIXED
Alias: None
Product: digikam
Classification: Applications
Component: Preview-Image (show other bugs)
Version: 1.0.0
Platform: Ubuntu Linux
: NOR normal
Target Milestone: ---
Assignee: Digikam Developers
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2009-12-06 12:24 UTC by DGardner
Modified: 2012-06-27 10:38 UTC (History)
2 users (show)

See Also:
Latest Commit:
Version Fixed In: 1.7.0
Sentry Crash Report:


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Description DGardner 2009-12-06 12:24:43 UTC
Version:           1.0.0-beta5 (using KDE 4.3.4)
OS:                Linux
Installed from:    Ubuntu Packages

When rating images, I preview them in full-screen mode and move
through them with "Space" and "Backspace".

In 0.10.0, digiKam sometimes failed to show the preview for the
next image after hitting "Space". The thumbnail bar showed that
the next image was selected, but until I hit "Backspace" and
"Space" a few times, the preview image was not updated and
continued to show the old image.

In 1.0.0-beta5, this problem still exists in another form. It is
so bad that I had to go an file this bug report for therapeutic
reasons. Every second or third image is not being shown on the
first attempt and some take two or three attempts. Unlike in
0.10.0, instead of continuing to show the previous image,
digiKam now shows a white screen in the preview area with the
message:

  'Cannot display preview for
         "<filename>"'

centred on the screen. If I hit "Backspace" and "Space" a few
times, the preview is eventually displayed.

I really don't want to know why digiKam "Cannot display preview";
I can only assume it is being belligerent. After all, the file
is there and if I kick it a few times, the preview is eventually
displayed.

Please, please fix this. If nothing else, I would prefer the
behaviour of 0.10.0 where it just looks like a bug. In 1.0.0 it
just seems to be taking the piss.
Comment 1 caulier.gilles 2009-12-09 11:29:46 UTC
Try with digiKam 1.0.0-rc

Gilles Caulier
Comment 2 Marcel Wiesweg 2009-12-22 20:44:06 UTC
You may imagine that this would be fixed if we could reproduce.
So, please report if this still occurs with 1.0, which types of files are affected, and if there is any output on the console (50003 enabled in kdebugdialog)
Comment 3 DGardner 2009-12-23 16:31:40 UTC
Same problem with digiKam 1.0.0-rc1--it just happened right now
with some files that I had newly imported. These are full size
15MP JPEG files from a Canon 50D, about 3-7MB each.

Sometimes the message is shown and a few seconds later the image
appears; other times, the image never appears and the message
remains. Right now, with these new images, it is a mix of both
(when it does not work first time).

On this particular set of images, the message appears for about
15% of them and remains for about 10% of them, which is about
average in my experience. When I reported the original bug, I
had a set of images where I was getting the message much more
frequently. It seems to happen mostly to new images. However,
most of my new images are from a new 50D that produces files
that are larger than any other camera I have owned, so maybe
the extra time taken to load them is causing some kind of
time-out. That might explain some of the behaviour, though
often a 7MB image will be fine and a following 4MB image
will not be shown on the first attempt.

I don't know what "50003 enabled in kdebugdialog" means, but I
ran digiKam from the console just now and nothing was reported
at the point that the message appeared instead of the image.
Comment 4 Marcel Wiesweg 2009-12-23 17:20:53 UTC
Start the "kdebugdialog" tool and ensure that 50003/digikam is checked.

Which sidebar is opened on the right hand side?
Do you load previews in full size?
Do you need to iterate quickly through your album or does it happen as well if there is plenty of time before going to the next image?
Comment 5 DGardner 2010-02-09 15:41:28 UTC
No sidebar: I'm in full-screen mode with a thumbnail strip on the left.

I view full-size previews only. (Reduced size previews would be useful
if they switched to full size previews when I zoomed in. Previously, I
used to delete images thinking they were out of focus until I discovered
that I wasn't looking at the original image! Never used reduced sized
previews again after that.)

I generally move quite quickly through the images, but it often happens
when I leave plenty of time (five or more seconds) between images. I'll
try to remember the debugging thing and get back to you.

Under what conditions is digiKam expected to display that error message
normally?
Comment 6 Marcel Wiesweg 2010-02-09 19:53:03 UTC
It will be shown if the file cannot be loaded, when the image loader cannot read it.
Comment 7 Marcel Wiesweg 2010-05-15 23:11:40 UTC
Any news here with a recent version (1.2.0)?
Comment 8 Andi Clemens 2010-11-29 22:04:35 UTC
Bump... any news here?
Comment 9 DGardner 2010-11-30 19:59:23 UTC
I haven't seen this problem for a while. I'm now on 1.4.0.

Is there a chance it is related to having read-only image
files? I noticed that the metadata was not updated (without
any warning given) in my image files because many of them
were read-only. I changed them all to read-write, but I
don't know if that would have made any difference.
Comment 10 caulier.gilles 2010-11-30 20:18:21 UTC
I think no. Read only image can be previewed as well...

So, i close this file now...

Gilles Caulier