Dear all;
I have sequence tga files form others and I have to composite them in my clip. These tga files are 720*576 resolution PAL system but I have to render to 720*486 resolution NTSC system .How can I convert
thses tga files from PAL to NTSC . I know the best way is rerender these files but I have not so much time .
So any ideas ?

Thanks advance.


Winnie

That just depends on what you want to do - you can resize them in COPs, but the aspect ratio will be wrong(squished vertically), or you can crop them, but you'll be missing information top and bottom which might affect your composition. You've composed for PAL, now you need to go NTSC without recomposing and re-rendering - it's just a decision that you have to make based on what the shots look like. I'm assuming you know how to use Scale and Crop in COPs, though…

Cheers,

J.C.

Well, there is no perfect way to do this since you are taking PAL 25 frame per second video (50 interlaced half frames) and trying to convert it to NTSC 30 frame per second (60 interlaced half frames).

There are ways to try to “deinterlace” them (if they are interlaced, but most likely they are) and then do motion estimation algorithms to try to put them in the right place for the different frame rate (which is what a program called “Twixtor” does), but that is difficult and complex and expensive and may be overboard for what you are trying to do.

If you don't care about it looking perfect to the biggest critical video geek (like me) and want it to stay cheap, there are a couple options.

Outside of Houdini I would suggest getting VirtualDub (www.virtualdub.org) which is a free program to process video (or use some other video tool) to do the PAL to NTSC conversion which may be decent or crappy, depending on how the program does it.

Inside of Houdini I would suggest that you treat your PAL frames like they are 24 FPS film frames and just to a 3:2 pulldown (perhaps after deinterlacing it first in COPs if it does that or do a “smart deinterlace” in VirtualDub before bringing it into COPs..) that is used to convert film to video. The files will slow down very slightly upon playback but it should be imperceptible. A lot of independent film-makers are shooting their films on PAL 25 FPS DV camcorders and then transferring it to film frame for frame and don't feel the slowdown is noticeable.

Also, if there isn't a lot of fast motion in your video clip, you can get away with much less effort in this conversion as dumb deinterlacing algorithms in almost any video package work well when there isn't much movement. With a lot of movement the dumb deinterlacing algorithms make the image a lot blurrier and “softer”.

Check out www.vcdhelp.com for articles on dealing with PAL to NTSC conversion.

-Craig

Here is a good site about deinterlacing with a lot of pictures:

http://www.100fps.com/ [100fps.com]

It doesn't cover PAL to NTSC though..

-Craig