PowerPoint and Live View

We have been starting out using the Live View and have found that when using PowerPoint 2013, the slides in the attached browsers do not appear to follow those in the projected image.  It is more obvious when there is a simple build in the slides (e.g. lines of text appearing) but can also apply to complete slides.  An update can be forced by a refresh of the attached browser but that isn't always helpful.  It's not always consistent.  We set up four browsers - two on android, two on iOS.  Between them, there was significant variation as to what was updated and when.  The PowerPoint slides themselves were not that difficult.  We were running Windows 10.

The corresponding stage view wasn't impacted.

Has anyone else seem this and more importantly, does anyone have a fix?




  • OpenLP doesn't show presentations or videos on the Live View (technological limitations).
  • Raoul
    Thanks for the reply but I am slightly confused since Live View does seem to show the PowerPoint presentations embedded in a service.  We have successfully demonstrated it work from our Windows 10 PC onto iOS and Android phones, PCs and macs by looking at the webpage at xxx.xxx.xxx.xxx:4316/main !  The only issue is that sometimes it is a slide behind.

    Am I missing something?

  • Well, it shows snapshots of the slides, it doesn't actually use PowerPoint and show the slides.
  • Thanks for the clarification.  The snapshots work fine for my requirements.  However, is there anyway for forcing the browsers to consistently do a refresh as the snapshots are updated?  As I mentioned before, in practice, I find that most browsers on mobile devices end up a snapshot behind after a short period - but not always.
  • OpenLP's stuff already tries to force the browser to refresh every half-second. Unfortunately the browser is in control, not OpenLP, so there's not much we can do.
  • Thanks.  What I find interesting is that 
    a) I don't see it in stage view
    b) The effect seems to imply some buffering is going on somewhere in live view.  This is because what we see is that if the slide is progressed, the attached browsers do update at that time, it's just that it is the last slide.

    To make it clear, here is a typical sequence
    a) PowerPoint slide 1 displayed inside OpenLP.  Attached browsers show this slide.
    b) OpenLP advances to slide 2, browsers stay on slide 1
    c) OpenLP advances to slide 3, browsers advance onto slide 2 and stay in that state until
    d) OpenLP advances to slide 4, browsers advance onto slide 3

    It's not 100% consistent - sometimes one of the attached browsers randomly will catch up.  
  • Hi, I just wanted to say that I have experienced the same issue, is there any chance of ironing this problem out. P.S. I've been using a similar setup since (i think) 2.4.1 and there wasn't any problems. Perhaps one day I'll go back and do some testing to see if that version worked.
  • Has there been any progress on resolving this matter? I still see the slide of delay very consistently with OpenLP 2.4.6 (i.e. the latest version) with every browser/machine I've tried (Win7/Win10/Android/ with Firefox/Chrome/IE) and would love to be able to get this sorted out.

    Given that this is just a problem with the presentation laptop displaying PowerPoint or LibreOffice slides, but not with image groups or songs etc., yet the web main view is just rendering snapshots in this scenario, presumably like when I show a group of images live (which is fine), I'm curious as to what the difference is and hence why it's a problem.

    If someone would be able to point me to where in the code this web feed is handled and how it's meant to work I might be able to look at what's going on with my system and fix it. (I know Python from my job as a software developer and can call in a friend who's knowledgeable about web stuff.)

    Rest of OpenLP is great, so thanks devs for your hard work producing this!
  • If it's of relevance, when I look at the raw html for the page that's served for the main view (at <ip>:<port>/main) I see the image field update without needing a browser refresh whenever I change song or image slide, but it only changes after a 1 slide or 1 animation (i.e. change of stuff on the output screen) delay for ppt, unless I manually refresh the webpage. It feels like somewhere something hasn't noticed that the output screen has updated, but that really is a guess.
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