Le 17.12.2006 00:19:06, Nicolas Maufrais a écrit :
Hello,http://cvs.cinelerra.org/docs/split_manual_en/cinelerra_cv_manual_en_5.html#SEC67
As I understand it, this part of the documentation is related to *importation* images into cinelerra from still pictures or other computer-generated source media.
There are two aspect ratios: - Image aspect ratio - Pixels aspect ratio PAL image aspect ratio is 4:3 But 720x576 gives a 5:4 pixels aspect ratio This is because the pixels on a TV set are not square.So, PAL does not have square pixels in mind because the pixel on a TV set areent square. But the pixels on a computer display are square.
This is the meaning of : New horizontal size=(5 / 4) / (4 / 3) x Original horizontal size This means:New horizontal size=(pixels aspect ratio)/(image aspect ratio) x original horizontal size
If the picture is from a "who know" source (like still images), Cinelerra cannot know the picture aspect ratio of the picture and it is up to you to convert the image for the right aspect ratio. But if the imported images are a PAL stream (or any known television standard), I suppose (I hope) there is no conversion to do. Neither to export the media as Cinelerra should do the proper conversion according to the video standard you have choosen in FIle-->Format. More probably the conversion is done to display the video correctly in the viewer and compositor and internally the pixture is still in the right format.
Regards Jean-Luc
On Sat, Dec 16, 2006 at 09:41:32PM +0100, Yannick Patois wrote: > Hi, > > If I understand, PAL DVD format have 25f/s images, 720x576 pixels, and > 4:3 aspect ratio. But I also read that those are non square pixels (they > must be because 720/576 != 4/3), and that point is worrying me. > > As I'm creating my movie from images, what would be the best for me? > Should I keep rendering 640x480 images (4:3 aspect ratio) images with > square pixels and let cinelerra work from it? Should I render 720x576 > images with non square pixels? > > Thanks for suggestions, > > Yannick >
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