🚀 go-pugleaf

Back by popular demand...

> Is there a standard resolution to render at when doing work for video?  If
> so... what is it?  And, if not... on what does it depend ?

The following video formats are in common use:

STD TV:
NTSC	Composite analog format with 525 total lines, and 485 active
59.94Hz	lines.  Since this format contains half-line definitions, one
	normally renders 486 full-sized lines.  The horizontal resolution
	depends on your video system.  Since this format has a 4/3 aspect
	ratio, you would expect to render 4/3*486 = 648 pixels in a
	square-pixel format.  The CCIR601 digital standard uses 720x486
	non-square pixels (still 4/3 aspect ratio).  If you wanted to use
	4Fsc digital (D2) you would have yet-another resolution.

PAL	Composite analog format with 625 total lines, and 575 active
50Hz	lines.  Since this format contains half-line definitions, one
	normally renders 576 full-sized lines.  The horizontal resolution
	depends on your video system.  Since this format has a 4/3 aspect
	ratio, you would expect to render 4/3*576 = 768 pixels in a
	square-pixel format.  The CCIR601 digital standard used 720x576
	non-square pixels (still 4/3 aspect ratio)


HDTV:
SMPTE	There is really only one digital resolution used here.
240M	1920 pixels by 1035 lines at 16/9 aspect ratio.
60Hz	This is a non-square pixel format.

Eureka	Once again, only one digital resolution is used.
1250	1920 pixels by 1152 lines at 16/9 aspect ratio.
50Hz	This is a non-square pixel format.


When producing material for video, you should be aware of the "TV Safe"
area which is inset 5% from the edges of active video.  You should not
have any important data outside this region of the picture.

Additionally, the "Safe Title" area is inset 10% from the edges.  You
should not have any text etc. that you want the viewer to see outside
this region.


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Scott Pritchett                    Silicon Graphics
Video Software Manager	 Advanced Graphics Division
skp@sgi.com                            415-390-3080
___________________________________________________




---------------------------------------------------
Scott Pritchett                    Silicon Graphics
skp@sgi.com                            415-390-3080
___________________________________________________