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View Full Version : Changing aspect ratio and speeding up comp


phix95
02-28-2006, 10:32 PM
I know AE alright but never had to deal with this problem:
In order to post my movie on a site, they need it to be 320x240, 15 fps NTSC. The movie I want to post was made for another project earlier and it is 720x480, 29.97 fps.
So how do I change the aspect ratio in this case so everything is at 320x240?
Also, I figure if I change it from 29.97 to 15 fps, it will end up playing slower so I suppose I will need to speed it up.
How do I go about doing all this?

Thanks

dbates
02-28-2006, 10:39 PM
Well, about the stretching: just import the rendered movie into a new composition, and scale it to 320x240, and render it to a new movie. It will squash the video unless you scale it proportionally, in which case you will have black bars on the top and bottom of the screen.

Changing the new composition's frame rate to 15 fps will not (as far as I remember) change the speed of the composition. It will simply drop nearly every other frame. So it will be choppy, but the same length.

phix95
02-28-2006, 11:00 PM
Hey thanks. I always forget rendering it out first. Duh. But as for the choppiness, it needs to be smooth and at the same speed. Duration isn't an issue. How do I do that?

Thanks!!

dbates
03-01-2006, 12:38 AM
15fps is always going to be choppier than drop-30, no matter what clip length. The computer is only playing 15 individual frames per second, instead of thirty (which would give the illusion of motion).

Check this page out for more info:
http://en.wikipedia.org/wiki/Persistence_of_vision

beenyweenies
03-01-2006, 01:38 AM
Hey thanks. I always forget rendering it out first. Duh. But as for the choppiness, it needs to be smooth and at the same speed. Duration isn't an issue. How do I do that?

Thanks!!

If you need to compress your movie for the web, don't bother doing anything too fancy except pulling your movie into a comp in AE and adding it to the render queue. Then, here's what I would recommend in terms of settings:

In AE's render setup, tell it to stretch your movie to 320X240 RATHER than nesting it into a small comp. Choose quicktime as your output type, and in the settings dialog choose Sorenson Codec. Open the Sorenson options dialog and set it to 15fps. Also set the codec to use 2-pass VBR (variable bit rate). with a datarate around 584 - 850.

With these settings (or any for that matter) your footage would not be slowed down by a 15fps frame rate - note the "per second" part - it will just use less frames to represent each second of footage. It WILL look slightly less smooth, but that's what happens when you use 15fps. The ideal is to use full 29.97 but just find a good compression setting that gets the file size down.

Good luck!

phix95
03-01-2006, 06:22 AM
Thanks. I'll try that. But just to be thorough, here are their specific req's:

QuickTime:
Video Codec: Sorenson Video 3 Compressor
Audio Codec: QDesign Music 2 Compressor
Aspect Ratio: 4:3 Standard NTSC/PAL, Image Size: 320x240 pixels
NTSC Frame Rate: 15 FPS
PAL Frame Rate: 12.5 FPS
Recommended Video Data Rate: 400 Kbites/Sec
Recommended Total Data Rate (Including Audio): 460 Kbites/Sec
Note: Select "AutoPlay" in window.


Media player:
Video and Audio Codec: Windows Media Player 7 and Higher
Aspect Ratio: 4:3 Standard NTSC/PAL, Image Size: 320x240 Pixels
NTSC Frame Rate: 15 FPS
PAL Frame Rate: 12.5 FPS
Recommended Video Data Rate: 400 Kbites/Sec
Recommended Total Data Rate (Including Audio): 460 Kbites/Sec

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