please upload a simple test case with those slide transitions where you see that glitch.

Created attachment 99209 [details]
minimal test case

This is a minimal test case file.
Slide transition 'fade smoothly' from a slide with black background to one without (white).

I tested the same on an Ubuntu 13.10 system, with Libreofficce 4.0, also with Nvidia card but with proprietary drivers. There the glitch did not appear.
Could it be be that this is not a problem of LibreOffice but of glx?

no problem with test case under Win7x64 using LibO 4.2.4.2.

Thanks for the test.
Any suggestions how to track down the source of the error I see? It would be interesting if someone else could test this under Fedora Linux.

Requesting advice - but I believe this is NOTOURBUG. I'll let a developer who knows a lot more than I do set the status though :)

I am experiencing the same behavior. I've had to turn off the transitions to avoid the white flash.

A bit of history that might be helpful. I'm using Linux Mint 17 now. I was running Linux Mint 16 previously and did not see this problem in LibreOffice (not exactly sure of the version). I installed OpenOffice at the same time, and OpenOffice did show the white flash. I upgraded to Linux Mint 17 this summer and LibreOffice started the flashes. I have received a new laptop since then, put Linux Mint 17 on it, and it also flashes. This is with LibreOffice 4.2.4.2, Build ID: 420m0(Build:2)

My current hardware is a Dell Latitude E5440. The OpenGL is provided by Mesa 10.1.3 with the Vendor shown as "Intel Open Source Technology Center".

lspci shows: VGA compatible controller: Intel Corporation Haswell-ULT Integrated Graphics Controller (rev 09) (prog-if 00 [VGA controller])

If this is a regression a bibisect would be nice:


https://wiki.documentfoundation.org/QA/HowToBibisect

Further information: I ran 'apitrace trace /usr/bin/loffice' and showed a couple slides that flash during transition. It produced a ~/soffice.bin.trace (rather than loffice.bin.trace ? ). I then ran 'glretrace -s /tmp/frame ~/soffice.bin.trace' which produced little PNG thumbnails of all the frames as it's fading in the slide.

The third frame in the sequence is all white. The two before it look all black. The one after it is a dark rendition of the slide.

I know next to nothing about GL, but I ran the same test above using qapitrace, a graphical front-end to GL API tracing. qapitrace shows each of the API calls in sequence, and in frame number 2 (which is the third frame), it is showing the frame turning white after this API call:

glDrawArrays(GL_TRIANGLES, 0, 6)


It's probably also important to note that because of different screen and slide aspect ratios, the display puts vertical black bars on either side of the slide to fill the screen, and the white screen has those black bars on either side. So it looks as though something really did intend to show an all-white slide.

Here is a list of some of the API calls before that glDrawArrays() (from 'apitrace dump'):

348 glPushMatrix()
349 glDisable(cap = GL_DEPTH_TEST)
350 glBindTexture(target = GL_TEXTURE_2D, texture = 1)
351 glPushMatrix()
352 glScaled(x = 0.8989751098096632, y = 1, z = 1)
353 glEnableClientState(array = GL_VERTEX_ARRAY)
354 glEnableClientState(array = GL_NORMAL_ARRAY)
355 glEnableClientState(array = GL_TEXTURE_COORD_ARRAY)
356 glTexCoordPointer(size = 2, type = GL_DOUBLE, stride = 0, pointer = blob(96))
357 glNormalPointer(type = GL_DOUBLE, stride = 0, pointer = blob(144))
358 glVertexPointer(size = 3, type = GL_DOUBLE, stride = 0, pointer = blob(144))
359 glDrawArrays(mode = GL_TRIANGLES, first = 0, count = 6)

I'll keep the trace around. Its over 2MiB so I'm not sure if it can be uploaded.

LibreOffice 4.2.6.3
Ubuntu 14.04.1 AMD64 (brand-new install)
Dell Latitude E5400
Intel Mobile 4 Series Integrated Graphics

I am also experiencing the same issue with a white flash on slide transitions when using Fade smoothly.  File format is .ODP.  System is a fresh install on clean drive, fully up-to-date, and no additional drivers to install.

Just figured I'd add my experience as well since I'm not the only Latitude E5400 series laptop having this issue.

set status to NEW because of independent confirmation in previous comment.
has anybody of the reproducing users already tried LO 4.3.2.2? is issue still there?

I have not tried LO 4.3.2.2 yet and I am on a time crunch to get this present done tonight...yay.  However, I will give it a try (after my presentation tomorrow) on the same file to see if I still have the issue on the newer version and report back.  For now I am just going without the transitions.

I just installed 4.3.3.2 and the white flash just happened.

I have a theory about what is happening. Through the year and a half that I've had to do presentations regularly, I have usually seen this problem, but as I went from one version of LibreOffice to the next, its behavior changed slightly. E.g., for 4.3.2.2 and 4.3.3.2, the flash does not usually occur, but for earlier versions, it usually did occur.

Because of the nature of the variations, I think that the performance of my computer may be a factor. When I use a cpufreq applet to keep the processor running full speed, I do not believe I have seen the flash occur. So I suspect there is a race between drawing in a buffer and the graphics code displaying it. Perhaps the buffer is being displayed before it has been filled, and thus we see a flash.

(In reply to ablumer from comment #14)
> I just installed 4.3.3.2 and the white flash just happened.
> 
> I have a theory about what is happening. Through the year and a half that
> I've had to do presentations regularly, I have usually seen this problem,
> but as I went from one version of LibreOffice to the next, its behavior
> changed slightly. E.g., for 4.3.2.2 and 4.3.3.2, the flash does not usually
> occur, but for earlier versions, it usually did occur.
> 
> Because of the nature of the variations, I think that the performance of my
> computer may be a factor. When I use a cpufreq applet to keep the processor
> running full speed, I do not believe I have seen the flash occur. So I
> suspect there is a race between drawing in a buffer and the graphics code
> displaying it. Perhaps the buffer is being displayed before it has been
> filled, and thus we see a flash.

On my laptop (Compa

(In reply to pieter kristensen from comment #15)
> (In reply to ablumer from comment #14)
> > I just installed 4.3.3.2 and the white flash just happened.
> > 
> > I have a theory about what is happening. Through the year and a half that
> > I've had to do presentations regularly, I have usually seen this problem,
> > but as I went from one version of LibreOffice to the next, its behavior
> > changed slightly. E.g., for 4.3.2.2 and 4.3.3.2, the flash does not usually
> > occur, but for earlier versions, it usually did occur.
> > 
> > Because of the nature of the variations, I think that the performance of my
> > computer may be a factor. When I use a cpufreq applet to keep the processor
> > running full speed, I do not believe I have seen the flash occur. So I
> > suspect there is a race between drawing in a buffer and the graphics code
> > displaying it. Perhaps the buffer is being displayed before it has been
> > filled, and thus we see a flash.
> 
> On my laptop (Compaq 6720s - Intel GME965/GLE960 Integrated Graphics Controller, Kubuntu 14.04 32 bit, LO 4.4.0.3) - I have this white flash effect too. The flash is very short but rather intens.

> On my laptop (Compaq 6720s - Intel GME965/GLE960 Integrated Graphics Controller, Kubuntu 14.04 32 bit, LO 4.4.0.3) - I have this white flash effect too. The flash is very short but rather intens.

Sorry, this went wrong. This is the more elegant way to say something here.

Just an update. I am now using 4.4.0.3. The flash still occurs. I have also seen it occur when cpufreq is set to maximum CPU frequency, but it does seem to happen less often. So I am still suspecting a race of some kind.

I am testing 5.0.0.2 Kubuntu 14.04 32 bit.

There has always been a white flash during 3d transitions on this computer. With 5.0.0.2 the flash perhaps got a little shorter.
But it clearly is still there.

The cpu is not a speed monster on this machine http://www.cpubenchmark.net/cpu_lookup.php?cpu=Intel+Celeron+M+530+%40+1.73GHz&id=705 (single core) it is possible that that has something to do with it.

Created attachment 118470 [details]
screencast demonstrating the issue

FWIW, I'm also seeing this on Fedora 22 64-bit with open-source "radeonsi" drivers for the Radeon HD 7770, running GNOME Shell 3.16 on X11.

This is with LibreOffice 5.0.1.2 (official RPMs downloaded from the LibreOffice website)

Created attachment 120780 [details]
some transitions impacted by the color's bug

I've tested some of transitions and record a little movie (see attachement)

I'm running on Win10 family 64bits, with Intel+Radeon videocard (HP4740s notebook)
I've tested with 5.0.(1 to 3) and with Libreoffice 5.1.0 alpha release (november, 24th)
Version: 5.1.0.0.alpha1 (x64)
Build ID: 0b48731919433e46e4fda7e5a5ca27c08c28b981
Locale : fr-FR (fr_FR)

As you'll see, forms and texts colors changes while transition occurs and get back at the end of effect.
Not all transitions are impacted but the most important one (Fade smoothly) cause problem (especially when showing educational curses to my students or when trying to record animation for education purpose)

Graphic card detail : AMD Radeon HD 7650M

Seems to be solved in 5.2 alpha1 release of LibreOffice.
Version: 5.2.0.0.alpha0+
Build ID: 1ed6d1423c7cffa5403dad69a9946ec790a374f2
Threads 2; Ver: Windows 6.19; Render: GL; 

TinderBox: Win-x86@42, Branch:master, Time: 2015-11-29_01:57:00
Locale: fr-FR (fr_FR)

nice to hear that.
set status to RESOLVED WORKSFORME

other users are encouraged to retest.
if the fix is verified we could do a reverse bibisect in order to obtain a 4.1.x backport

Sorry, bad bug number (I'm following two bugs :( )
It still a small flash from transition to final slide... so it's not solved !

(I've to search for the second bug with colors in transitions that are inverted)
However, there is a causal effet : if colors are inverted, at the end of the transition, it could show a white flash.
For now, it still a flash but not white : I would say, like a snapshot with a different scale or few pixels offset.

Created attachment 121024 [details]
square while transitions (flashing)

I've made some new tests : in fact, the transition occurs and at the end, the previous slide appears one frame !
on the attached slides, each square is removed on each slide, but while transition, near the last time of it, the previous slide (say 'A') with square present where it was removed on new slide (say 'B').

The strange thing, is I can't record it (with NCH Debut software), like this flash occurs between two synchronisation screen

Wrong status.

As my english wasn't very clear (sorry!) here is a better explanation :

[SlideA] -- SlideA mixed with SlideB -- [SlideB] [SlideA a very short time] [SlideB]

(In reply to roumanet from comment #27)
> As my english wasn't very clear (sorry!) here is a better explanation :
> 
> [SlideA] -- SlideA mixed with SlideB -- [SlideB] [SlideA a very short time]
> [SlideB]

No problem here.

Ubuntu 15.10 64-bit 
Version: 5.0.3.2
Build ID: 1:5.0.3~rc2-0ubuntu1
Locale: en-US (en_US.UTF-8)

Not reproducible for me with the minimal test case with LO 5.0.5.0.0+ under Ubuntu 15.10 x86-64.
That said the status unconfirmed is wrong because this bug has been confirmed (see history). Set back to NEW.

Best regards. JBF

On this Windows machine, (32 bit W10) the problem has become less. The flash is not white any more but at the end of the transition there is a distorsion. All 3d transitions do this.

Same symptoms in 5.3.0 alpha 1.  On windows 10 64bit and Lubuntu 16.04 64 bit.

The very last step of the fade-in for a split second shows what's underneath.  Seems like a weird Z-layering/transparency issue.

E.g. transitioning from Slide A to Slide B with fade smoothly looks like:
A + B @ 0% transparency
A + B @ 10% transparency
A + B @ 20% transparency
A + B @ 30% transparency
A + B @ 40% transparency
A + B @ 50% transparency
A + B @ 60% transparency
A + B @ 70% transparency
A + B @ 80% transparency
A + B @ 90% transparency
A + B @ 0% transparency  <-- zero percent transparency ??
B @ 100% transparency 

For a split second B disappears so you get a "Flash" of the previous slide  below it.  

I think these bugs slide/animation transition problems are all the same:

slide flash
https://bugs.documentfoundation.org/show_bug.cgi?id=73273

slide transition
https://bugs.documentfoundation.org/show_bug.cgi?id=95479

Animation problem:
https://bugs.documentfoundation.org/show_bug.cgi?id=47341

There are many other duplicates of this bug.  I really hope this can get some attention.

This is older bug, not obvious. Please retest. Please see bug 91456.

In response to Comment #36.

In LibreOffice 7.062 the minimal test case works without problems.
The problem seems to be solved

Thanks!

I still see a flash(on Windows)
Version: 7.3.0.0.alpha0+ (x64) / LibreOffice Community
Build ID: 93115d2c54d645bcf2f80fde325e3ede39dee4d5
CPU threads: 4; OS: Windows 6.3 Build 9600; UI render: Skia/Raster; VCL: win
Locale: nl-NL (nl_NL); UI: en-US
Calc: CL

Seems we had earlier Windows confirmations, but OS was not changed to All.

It is working on my machine using LO 7.3 alpha (build from Oct 14) and the kf5 backend. I used the "minimal test case" and it worked as expected, without the initial flash.

Version: 7.3.0.0.alpha0+ / LibreOffice Community
Build ID: c998691e22ceda15c89d55cf7005201f0392dadb
CPU threads: 16; OS: Linux 5.11; UI render: default; VCL: kf5 (cairo+xcb)
Locale: pt-BR (pt_BR.UTF-8); UI: en-US
TinderBox: Linux-rpm_deb-x86_64@86-TDF, Branch:master, Time: 2021-10-14_11:54:20
Calc: threaded

Maybe a Windows-only issue?

On LO 7.5.7.1 the bug is not present any more and the minimal test case works as expected.

I cannot say exactly what version resolved it, though.

Marking as resolved. Thanks to all who have contributed!