Thursday, August 09, 2007

Trial and Errors

I finished the HD green screen test last night. Unfortunately, I haven't figured out how to show it to you yet. Let's see if I can explain this.

My HDV camera shoots frames that measure 1280 by 720 pixels. That's what I see in my Adobe Premiere Pro video editing program. If I use only video shot with that camera, it's fine. You can see that in the first HD test I posted.

But this time, I used an animated background and photographs of different dimensions. When I import them into Premiere Pro and add them to the video timeline, I can get them properly framed in the monitor window. Within the program the video plays in its proper 16:9 aspect ratio and looks like it should, as the still frame capture below shows.


The problem comes when I try to export the finished movie. When I export it as an AVI file, look what happens:


Instead of the 16:9 ratio, it creates a video file that's 4:3. Worse, it shows parts of the background photo that are supposed to be cropped just like in the first still frame capture. Back on the original HD test, I couldn't tell there was a problem because there was no background (or foreground, in the instances where I cover my face with a photo or video) so when creating the AVI file the extra space above and below the frame showed up black -- the so called "letterboxing" effect.

Premiere Pro has encoding software for other formats so I tried some. Flash video (FLV) would be great, that's the most easily viewed by Internet browsers, so it would work better here than the QuickTime movies I usually use. So I tried that.


Oops. That's not good. I noticed that in the place where I want to save the Flash file I'm creating, it makes the file but adds a ".mov" end the end of the file name. Something like this: "HDGreenScreen1.flv.mov" which is obviously not right.

What about QuickTime? That seemed to work. I could adjust the dimensions so that it would create a 16:9 file. Great! But when I played the QuickTime movie, the audio and video came unsynched about a minute or so into it. By two to three seconds. It did not seem to get progressively worse as the file played. The audio began lagging suddenly and stayed the same distance behind for the rest of the movie. The video turned white when the last video frame ended as the audio kept going.

I made a Windows Media file but that had the same problems as the AVI. I exported the movie as an MPEG2 file but the file it created had a .m2t suffix that my computer didn't recognize. I tried to burn a DVD from the timeline but it would create only a 720x480 size, not only the wrong aspect ratio but much smaller than the 1280x720. And it didn't shrink the video to fit in the frame, it simply cropped it.

This is a long-winded way of saying that I've got some research to do before I can show you how well (I think) my green screen test worked. I'd look in my Adobe user guide but it's not really helpful. They want you to buy the tutorial. It's not enough to pay for the program. Adobe wants you to pay again if you want to learn how to use it.

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