On Tue, 2007-05-22 at 23:17 +0200, Terje J. Hanssen wrote:
> HDV 1080i uses a pixel resolution 1440x1080 on tape. The rectangular
> pixel aspect ratio h:v=4:3=1.33, so when displayed the video frame is
> scaled to an aspect ratio of (1440x1.33)x1080=1920x1080 or 16:9.
> 
> What I wonder is:
> 
> 1) Does the HDV video frame imported to Cinelerra get a resolution of
> 1440x1080 with aspect ratio of 16:9 or does it being transformed to
> 1920x1080 resolution? If 1440x1080 is correct how can it possibly get a
> true 16:9 aspect ratio, if the display pixels is square and not rectangular?

 The display has to be stretched by the player.  If Cinelerra is told 
that the resolution is 1440x1080 and the aspect ratio is 16:9, it will
scale the image to fit the specified aspect ratio.

 Everything in your project will have to take those non-square pixels
into account, as the "native" shape of the 1080i HDV pixels is
rectangular.  The same goes for 4:3 DV, to a modest extent. 

 As long as you work with raster graphics, you can not expect this 
complexity to be hidden from you, as rescaling is lossy, and should
be kept to a minimum.


> 2) If HDMI can be used instead of i.Link (1394) to import video to
> harddisk, 

 I don't think you'll find HDMI inputs.  Just like there are no
cheap and common VGA or DVI "grabbers".  Those interfaces are one 
way only.


> what kind of video format does this result in. 

 Raw RGB.  But the disk would be too slow.

-- 
 Herman Robak


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