Buffering Issues

[RPW]

We publish PowerPoint (2007 & 2010) presentations with audio using Adobe Presenter (v7 and v9). We then upload the zip folder onto our AdobeConnect server. From there, we share the presentation in an Adobe Connect (v9) seminar room, and play the recording. We have two issues:

1. Major Buffering: When the presentations have videos or "Advance by User" slides, the presentation buffers for minutes or ad infinitum.
   
   
2. Minor Buffering: When the presentations have only audio and we click around and the settle at one, the slides buffer for under a second at each transition.

Has anyone else experience the Major and Minor buffering issue? Does anyone have a workaround?

Thank you.

[Jorma_at_CoSo]

You may be fighting a couple things.

First, check in the Quality section of the Settings tool that the 'disable preloading of Flash content' isn't selected. That setting means that each slide starts loading when the viewer gets to it, so a buffering message will be seen on every slide.

Second, it's worth knowing how Presenter pre-loads, as you are getting ahead of it, and probably seeing the buffering as a result. When you load a Presenter Presentation, the first three slides load fully during the loading screen (now you know why that presentation that has a 15 min video on slide 3 takes so long to load). Then an additional slide begins pre-loading every 3 seconds. So, slide 5 will begin preloading 6 seconds into the presentation playing back, for example. So, skipping to slide 38 right after the presentation starts playing will cause a buffering message and a wait due to the fact that that slide hasn't yet preloaded.

[BlauKirsche]

Hi Jorma,

I am a week into an Adobe Presenter trial, and happily I seem to have overcome a series of challenges to date. I am now so close to buying but am struggling with buffering during playback.

As you pointed out in response to RPW's query, I had, indeed, disabled preloading and I'm sure that was the main cause of my major buffering issues. So I thank you for that tip.

However, the buffering continues, although to a lesser extent, requiring the user to hit the advance slide button to load every slide from the point at which the buffering begins. Up to that point, all slide transitions are automatic as per Powerpoint.

Would you have any further tips for me?

Many thanks in hope.

[Jorma_at_CoSo]

Other than looking at the content of your presentation and seeing if there are large objects (images and/or videos) that may be causing an issue, the only other change that I can think of making would be limiting the number of slides that are pre-loaded. This may help limit the bandwidth demand of presentations loading if many of the slides have large objects on them. No promises on it changing anything, but may be worth a try. Here is the process (and credit should be given to Adobe Support for passing along this information to me a while back). It should be noted that this was for Presenter

1). Publish from Presenter locally on your hard drive.

2). Navigate to the folder where you have published the presentation from step #1

3). Locate the vconfig.xml its in the data folder:

4). Add following tags in the vconfig.xml,  This will preload only 3 slides from the current slide.

<preloader>

<setBool name="precacheSlides" value="false"/>

<setInt name="getNPrecedingSlides" value="1"/>

<setInt name="getNSuccessiveSlides" value="3"/> <!--here you specify the number of slides you would want to preload from the current slide-->

</preloader>

<preloader>…</preloader> tags are sibling to <colors>…</colors> tag.

1. e.g.

</colors>

<preloader>

<setInt name="audioBufferTime" value="0"/>

<setBool name="precacheSlides" value="false"/>

<setInt name="getNPrecedingSlides" value="1"/>

<setInt name="getNSuccessiveSlides" value="3"/>

</preloader>

<language id="en">

5). Zip the published content with the modified vconfig.xml file and upload it to Connect.

Give it a shot, play with the numbers and see if any of these values will help.

[BlauKirsche]

Firstly, many thanks for the prompt response.

I have a question regarding your response.

Should the tags you have shown replace the one currently standing within the preloader section, or should they be placed before or after it?

The current layout is:

<preloader>

     <setInt value="0" name="audioBufferTime"/>

</preloader>

In trying to diagnose the cause, I have noticed the following:

- The same problem occurs when running the preview

- The same problem occurs in Internet Explorer & Chrome

- It is now consistently happening at the end of the slide with the largest narration audio file (a 3,649 KB MP3 - 5 minutes)

Before I attempt your recommended changes, I'll split the slide into two slides in an effort to nail this down, and I'll let you know the outcome for future reference.

Many thanks.

[Jorma_at_CoSo]

You will want to add to the existing tags, not replace them. Though you could also change the audio buffer time value and see if it works any better/worse.

Since the problem is seen consistantly across all methods of viewing (you might try publishing to PDF just to see if it happens there), I suspect it something to do with that slide, and possibly its audio. You might try removing the audio (save the file somewhere of course) and then either re-inserting the audio or re-encoding it and then re-inserting it to see if there is just some strange corruption there. I have had plenty of slides with more than 5 minutes of audio on them and haven't seen this problem before.

Let us know what you find.

[BlauKirsche]

Hi Jorma,

You were right to suspect the slides and specifically the audio associated with them.

The buffering problem arose at the end of 5 of the 18 slides, and each of the 5 slides was fixed simply by deleting the audio file and then inserting the same audio file from the same source as previously.

Since I created the audio from within PowerPoint rather than within Video Express, the cause of the problem would appear to be within PowerPoint, and not within Presenter 10. I'll be trying the Video Express option next.

Many thanks for your support through this challenge.

[BlauKirsche]

Hi RPW,

Please forgive the intrusion, but did you ever resolve your buffering issue?

I was confident that Jorma's suggested remedy would resolve the issue, but unfortunately not.

Many thanks in hope.

[Saumitra15A7]

This is an old ticket but wanted to share a resolution. This is happening with one of our clients and the solution is to have user do a 'click' - browsers are blocking auto-play and work fine when users click or interact using scrubber in the UI or any other mechanism to interact with the slide. What we did is included a launch file that redirected to the index.html (the start page) but has to be in the same window. And the buffering issue is resolved.