Playing videos from a PC to a data projector

[Bus429]

Hello,
I've recently taken delivery of an ACER Aspire 9104WLMi. I use it to present Powerpoint using a data projector. I also play video through Powerpoint and standalone. If I play video with the computer's display and the data projector valid, video will not show through the projector but will show on the computer's display. If I deselect the computer's display, video plays through the projector no probs. I've tried using "HELP" and various graphic accelerator topics but cannot find the specific fault.
Any ideas?

[Conan the Librarian]

Try Fn-F5 for starters. That is the Aspire Hotkey to switch displays.

Conan

[CBLong]

Hi Bus,

I've been playing with video playback from my Thinkpad to my TV recently, so my experience may be relevant... Is your projector connected to a standard VGA connector on the back of the laptop, or via S-video (a small round plug)? On my Thinkpad, the output from the VGA connector is just a duplicate of what you see on the screen, but the S-video output actually comes from a second (possibly virtual) graphics card. From the "display properties" dialog, I have to enable the TV as a second monitor, and can then move windows back and forth between the computer screen and the TV. Something to look into, perhaps.

The reason I suspect something along these lines is this - when you play back video on a modern graphics card, the video picture isn't technically part of the main windows desktop - it's overlaid by some other part of the electronic wizardry. For example, on my laptop, if I play a DVD in a window (ie not full-screen) and try to grab a screen-shot, all I get is a blank rectangle. Similarly, if I pause the DVD and the move the window, I get some very strange effects.

Your problem sounds like the video is possibly being overlaid onto one or other of your outputs, but not both.

On the other hand, I could be completely wrong... :)

Crispy.

[Jhieminga]

Sometimes you can get problems like this if the resolutions on the laptop and projector aren't matched. Some laptops use widescreen displays with unorthodox resolution settings. If you then try to get this image onto your data projector it won't accept this setting. Setting the laptop to 1024x768 might solve this.

Another thing to try might be to go to your display driver settings, and disable 'hardware acceleration'. This is what CBLong is explaining, the hardware is used to build the image, and disabling this setting forces Windows to render the image as a normal graphic. CBLong: This will also allow you to take a screenshot from a video (performance is affected with this setting, but that's not important for the screenshot).

[Crashing Software]

This is one of those "it's not a bug, it's a feature" type things

CBL is on the right lines. When a "normal" program displays something, it's using the Windows GDI (Graphical Drawing Interface) so all the API calls to draw something on the screen effectively go through the operating system, hence you can do screen captures, print screen etc.

However, that approach is waaaay too slow for video, so that's displayed using DirectX - in brief this allows the application to get a pointer to the RAM on the graphics card, and directly set the pixels as required. As the OS isn't involved, which monitor the results are displayed on depends on the application, and AFAIK, currently they all default to the laptop screen - unless that's selected off.

So, if you have a projector connected to the laptop (i.e. acting as a monitor) video can only be displayed on one screen at any one time. The black rectangles that should have the video inside them appear because the OS DOES know about the borders of the window.

Hope that helps

[Bus429]

All,

Thanks for info. FN-F5 is for switching displays - no probs there. Will try other suggestions.

:)