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-   -   Video direct out of projector to Camera? (https://www.dvinfo.net/forum/open-dv-discussion/37938-video-direct-out-projector-camera.html)

Jeff Toogood January 18th, 2005 07:26 AM

Video direct out of projector to Camera?
 
I am filming a day long seminar at the end of the month which consists of several speakers presenting their powerpoint presentations. What I thought about trying was if possible taking a video out from the projector right into my backup camera and using it in the final edit when I need a detailed shot of a slide.

In the past I have run the powerpoint through CamStudio which converts it to a AVI, but it is a very time consuming and tedious job. (especially getting the timing of the presentation right)

Anybody try this? I assume I would need some sort of VGA to RCA cable?

Jeremy Davidson January 18th, 2005 09:41 AM

What you're thinking of doing is possible, though you'll need more than just a VGA to composite (RCA) "cable." A device known as a scan converter will take the VGA signal (which uses many separate wires for the RGBHV signals) and convert it to a composite or S-Video signal that you can input into your camera. It'll also convert the high-resolution PowerPoint image (which is hopefully 1024x768) down to standard NTSC (720x480). Some converters may also shrink the image to keep it within the TV safe zone.

You may notice more artifacting on the images if you're doing to DV. My experience with computer graphics is that DV doesn't handle the sharp, high-contrast edges very well ('though it could partially be my cheap codec).

Why is Camstudio so time consuming? I thought it captured straight to AVI (so your slides should already be timed properly). Can you give more detail on your post-production process?

Jeff Toogood January 18th, 2005 10:03 AM

Camstudio is so time consuming because I don't run it live at the show, because I find it bogs down the user's computer too much.
So usually I take a wide shot of the screen and in post I have to record the powerpoint presentation (by me running it) to avi by following the tape that I recorded for the proper slide timings, because most of these speakers don't use pre-planned timing in their presentations.

Jeremy Davidson January 18th, 2005 03:44 PM

Ah, now I understand.

What if you took your second camera and simply pointed it at the projection screen? It wouldn't have very good quality, but it would give you your slide timings. Once you put that on the timeline, take your screen grabs from PowerPoint (aka Camstudio) and align them to the video track. This would give you a guide for the timings but with the maximum quality possible.

One other thought: newer versions of PowerPoint have the ability to export slides as JPG's or BMP's. I believe they're at a resolution right around video (720 x something). This may save you a step if you still want to substitute still images for the slides.

If you go that route, let me know if you figure out how to change the export resolution. I haven't found that setting yet. If, however, this is still too much work, recording through a scan converter to DV may be the best route (are there other recording formats that can take VGA directly... anyone?).


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