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Re: IDLtoAVIGENERATOR gives unexpected output when dimension is not power of 2? [message #52114 is a reply to message #52105]

Mon, 08 January 2007 09:39

Rick Towler
Messages: 821
Registered: August 1998

Senior Member

The issue is most likely related to the fact that your frame sizes
aren't evenly divisible by 4, 8, or 16. To be safe, your frame sizes
should be divisible by 8 and some codecs are optimized for 16. I am
stumped as to why the demo 300x400 works but your code doesn't. I
suspect that you used different codecs between the test and your code.
I'll guess the test was done with the cinepack codec?

Stick with "legal" frame sizes and you should have better luck.

-Rick

biophys wrote:
> Hello,
>
> I've been using idl2avi.dlm and lately the new IDLtoAVIGENERATOR.dlm
> quite a few times and it all gives me satisfactory results. Recently I
> need to make avi output under windows with some random size, say
> 258x349, not 128x128,256x256 as usual. The program runs smoothly and
> generates avi output. However, when I open avi with windows media
> player, the frames are like skewed by 30 to 60 degrees and sometimes
> the color is also screwed up. When I force the program to feed 256x256
> images, it works fine. It seems to be codec independent and
> reproducible in different machines. Also it does not matter if it is
> generated with 8bits or 24 bits. My guess in the title may not be
> completely true since I did not try all possible combinations of
> dimensions. The example testAVIgenerator works with its default size
> 300x400, but not some other size 258x349. But strangely 300x400 does
> not work in my program. I also had good luck with size of 512x[some
> random dimension smaller than 512] or [some random dimension smaller
> than 512]x512. I am totally lost here. Am I the only one who has this
> problem? Can someone help me understand this?
>
> Many thanks!
> BP
>

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[Message index]

		Re: IDLtoAVIGENERATOR gives unexpected output when dimension is not power of 2? By: Haje Korth on Tue, 09 January 2007 10:07
		Re: IDLtoAVIGENERATOR gives unexpected output when dimension is not power of 2? By: biophys on Tue, 09 January 2007 00:36
		Re: IDLtoAVIGENERATOR gives unexpected output when dimension is not power of 2? By: Rick Towler on Mon, 08 January 2007 09:39
		Re: IDLtoAVIGENERATOR gives unexpected output when dimension is not power of 2? By: Haje Korth on Mon, 08 January 2007 05:28
		Re: IDLtoAVIGENERATOR gives unexpected output when dimension is not power of 2? By: badjelly.witch on Wed, 10 January 2007 15:17

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