Bug 284368

Summary: Unstable/Wrong duration for transitions with Beamer (LaTeX)
Product: [Applications] okular Reporter: Christophe NINUCCI <zbouboutchi>
Component: PDF backendAssignee: Okular developers <okular-devel>
Status: RESOLVED NOT A BUG    
Severity: normal    
Priority: NOR    
Version First Reported In: 0.13.2   
Target Milestone: ---   
Platform: Arch Linux   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:
Attachments: Testing document.

Description Christophe NINUCCI 2011-10-18 14:54:46 UTC
Created attachment 64670 [details]
Testing document.

Version:           0.13.2 (using KDE 4.7.2) 
OS:                Linux

Transition's timing is wrong and unstable.

Reproducible: Always

Steps to Reproduce:
Open the linked pdf file, go in presentation mode (ctrl shift P) and then go to page 2 and wait for count down to begin. 

Actual Results:  
The transitions should be 1 second long but it's not regular and take much time.

Expected Results:  
The transitions must be 1 second long.

I tested the attached document with acrobat reader X and timing is good. I tested on 2 different computers, with small performances (1.66ghz intel atom with 2gig ram...), timing errors are bigger.

I have exactly the same symptoms on slackware 13.37.

I can eventually attach latex source code, or generate a much simpler document.
Comment 1 Albert Astals Cid 2011-10-18 18:04:16 UTC
The problem is that rendering takes time, and the second only starts counting after the rendering is done. You can see that if you go to presentation mode, manually go throught some slides, and then come back to slide 2 everything will be much smoother since the pages will be rendered already.

Not much we can do to fix this other than rendering faster thus I'm closing the bug as INVALID. Sorry about that. If you want to complain about rendering speed open a bug against poppler in bugs.freedesktop.org
Comment 2 Christophe NINUCCI 2011-10-18 19:24:56 UTC
You're right, I just tried to let go a (slow) first pass and then restarted the presentation and the timing was far better (I'd rather say, it was perfect !)...

I thought background generation and aggressive memory management would pre-render and pre-load pages.. I enabled these options and waited a bit before running the presentation's second page but no preloading have been done in order to prevent the «lag».

Have I done something wrong or could it be a preload misbehavior ? (feel free to answer ;) ..) 

Thanks for your help !