Quote:
Originally Posted by jfs
As long as you haven't resampled the video frame, the SAR is constant regardless of crop. That's the point of using the sample aspect ratio, rather than the display (or frame) aspect ratio.
Also I believe that the sample aspect ratio for 16:9 480 line video would be more along the lines of 1.2:1.
480 lines / (16/9 pixels/line) = 853.33 pixels
853.33 display pixels / 710.85 encoded pixels = 1.2 stretch factor
Please correct me if I'm wrong.
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You're right, but there's an easier way to calculate it in my opinion.
DAR / SAR = PAR, so (16/9) / (3/2) = 32/27 = 1.18 = PAR.
(DAR is Display Aspect Ratio, SAR is Storage Aspect Ratio, and PAR is Pixel Aspect Ratio = stretch factor).
The PAR for 16/9 DVD video should be 32/27 (1.18)
The PAR for 4/3 DVD video should likewise be 8/9 (0.89).