[Digikam-users] crazy thumbnail syndrome

Mon Jan 19 20:12:14 GMT 2015

Hi all,
This sounds like a total nightmare but I found some hints that could
lead to a solution. We can simplify the definition of a syndrome as a
set of symptoms that seems to be related by a common cause. My DK is
experiencing several symptoms that seems to have a common cause despite
their differences.

_First the main symptoms of this "crazy thumbnail syndrome":_
- when grouping by Album, there are some album/folders that do not show
all their content. As an example it shows two thumbnails despite the
counter states 10 and using dolphin I confirmed there are indeed 10
photos there. Some of my albums appear completely empty. So, the hidden
thumbnails is the first symptom.
- large empty spaces between the albums. This may be just a consequence
of the previous symptom because albums that showup with all their
thumbnails, have no empty spaces separating from next album.
- the most weird, is that passing the pointer over some thumbnails, they
change!!! I mean the thumbnail changes and even the text underneath too
corresponding to other photo. It switches from the thumbnail
corresponding to the file A to the file B just by passing the mouse on
top rendering the thumbnail itself unreliable since I do not really know
if it corresponds or not to that album. Funny, when I scroll up or down
a bit, these switched thumbnails return to the previously shown
thumbnail. Again, mouse-over makes the thumbnail to switch again
repeating consistently the behavior.
- the switching thumbnails can occur as a complete change among
thumbnails or a partial case as overlapped thumbnails depending on the
zoom setting of the Thumbnail view mode.
- when filtering it is the same nightmare showing lesser thumbnails that
the real content of the folders.
- this is only happening to some images and not all images, they are
always the same with problematic thumbnails and despite their thumbnails
show-up perfectly fine when selecting their album directly (not as
sub-tree).

Too complex or needing a visual? ok, look this unlisted video and focus
on the content of albums 04 and 02...  http://youtu.be/FaIYpzCxYO0

_Now some light over this syndrome..._

* I checked the database connecting externally to it, and it is perfect.
Data allocated inside is fine, with all the tags perfect etc. Great. So
it is just the way DK presents on screen the thumbnails.

* erasing thumbnail.db to force rebuild the thumbnails or using the
rebuild tool does not solve the problem.

* Using Table instead of Thumbnail view mode, the thumbnails are all
shown and there is no crazy mouse-over nor large black empty spaces.
However the "group images by album" does not do anything on Table view
(that is another issue anyway). The point is that the problem occur only
under Thumbnail view mode and that all these symptoms have a common
cause because all of them are solved by simply changing the view mode.

* I tested every visualization combination and all the previous symptoms
occur under a specific visualization setting and only to some images
(not all). I did not find anything special (yet) to the images whose
thumbnails are shown under some settings and those that are shown
properly despite the settings.
The combination of terror is when having menu/View/ all the next settings:

a) Thumbnail view mode
b) enable the "include album sub-tree" and "include tag sub-tree"
c) Sort Images set on "by Date"
d) Group Images set on "by Album"

Any other combination is fine, but sadly this is the most useful for me...

_Partial solution_
just by changing "Sort Images" from "by Date" to "by Name" solves the
problem, no more crazy mouse-over behavior changing thumbnails, nor
missing thumbnails nor empty spaces. Since the file names from my camera
are time correlative, it ends by presenting the Thumbnails in an almost
same way to "by Date". Also, by changing "Group Images" from "by Album"
to "Flat list" solves the symptoms.

These findings suggest that our files are fine, since DK is able to show
their thumbnails properly in most cases but something is weird when
combining the "Group Images by Album" with "Sort Images by Date"
visualization settings.

_Probable related issues:_
Some time ago, Audun posted a similar symptom (no thumbnails). Also this
link to a post that seems to have similarities as well:
http://digikam.1695700.n4.nabble.com/no-photos-or-thumbnails-tp3073787.html
They do not mention the swuitching thumbnail mouse-over behavior but as
I mentioned it before, it happens also to some and not all thumbnails.
I cannot confirm my case is in fact related to audun's or others, but
maybe these cases can check if changing "sort images" from "by date" to
another option, solves their issues of "hidden thumbnails".

Other details:
This is happening to most of our boxes:

BOX1: asus desktop / nvidia / 6 cores / opensuse 13.2 / DK 4.6.0 / KDE
4.14.3 / Linux (x86_64) release 3.16.7-7-desktop.
BOX2: asus 4 cores / all the rest the same except it has DK 4.5.0.
BOX3: notebook HP pavillion / ATI / also with opensuse 13.2 (x86_64)/ DK
4.5.0
BOX4: notebook HP mini / ATI / also with opensuse 13.2 / DK 4.6.0 / KDE
4.14.3 / Linux (x86_64) release 3.16.6-2-default.
BOX5: asus 4 cores quite old / opensuse 13.2 / DK 4.6.0 / KDE 4.14.3 /
Linux (x86_64) release 3.16.7-7-desktop.

So the syndrome happens on DK4.5.0 and DK4.6.0 but not always. BOX3 does
not have this visualization issue (tested with the same images). All my
other boxes have the problem despite they have just being
clean-reinstalled and have different hardware. I know BOX3 had a patch
recently and BOX2 did not. Both are at the field right now and it is
hard for me to perform tests on them. However, in the case a patch
solved the problem on BOX3 (which I cannot confirm and do not know if
the problem was ever there before the patch neither), why boxes with
4.6.0 (a more recent version) have the issue anyway?

Hope this helps to solve the issue.
gps
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