rmedboer82
28th September 2008, 21:13
I've read the Determining the capture window of a capture card guide and I got a few questions regarding it.
I made several captures of the test DVD:
CAPTURE SIZE (PC) / DVD-PIXELS (MEASURED) / PC-PIXELS (MEASURED) -> RATIO (INVERTED RATIO) | CAPTURED DVD-PIXELS
1) 720 / 661 / 676 -> 1 DVD PIX = 1,0226 PC PIX (0,9778) | 704,0236 DVD-PIXELS
2) 768 / 661 / 721 -> 1 DVD PIX = 1,0907 PC PIX (0,9167) | 704,0887 DVD-PIXELS
3) 704 / 681 / 681 -> 1 DVD PIX = 1 PC PIX | 704 DVD-PIXELS
I know that 702 or 704 will give a 4:3 image. It looks like capturing on 704 would give a 1:1 correspondence between the DVD (or VHS) player, but looking at the images (see attachment) the lines look blurry compared to the other 720 and 768 captures. Can it be that the capture card did some resizing? And what would be the best capture format after seeing those images (some are text better and others lines better)?
How does the DVD (or VHS) player display these pixels? When writing to DVD will 720 resized to 704 or 702 and will these be stretched to get 720 pixels? Because anyone says that I just have to capture at 720 and burn it to DVD, but will these be stretched again then if it would not be shrinked to 704 or 702 (I assume it is somewhere stored in 702 or 704 format thus 1 pixel width)?
And when creating an AVI-file, would you create 3 PC pixels to fit in a DVD pixel for example (which has been 1 but now stretched to 3 because of the 13.5 mhz clock for example)? So you will retain the wide format? or will you resize by 1/3 so s stretched DVD pixel of 3 PC pixels will be 1 PC pixel?
I've read a lot of things about pixel aspect ratio etc but I somehow still missing the last step in this think process.
Thank you for your help.
I made several captures of the test DVD:
CAPTURE SIZE (PC) / DVD-PIXELS (MEASURED) / PC-PIXELS (MEASURED) -> RATIO (INVERTED RATIO) | CAPTURED DVD-PIXELS
1) 720 / 661 / 676 -> 1 DVD PIX = 1,0226 PC PIX (0,9778) | 704,0236 DVD-PIXELS
2) 768 / 661 / 721 -> 1 DVD PIX = 1,0907 PC PIX (0,9167) | 704,0887 DVD-PIXELS
3) 704 / 681 / 681 -> 1 DVD PIX = 1 PC PIX | 704 DVD-PIXELS
I know that 702 or 704 will give a 4:3 image. It looks like capturing on 704 would give a 1:1 correspondence between the DVD (or VHS) player, but looking at the images (see attachment) the lines look blurry compared to the other 720 and 768 captures. Can it be that the capture card did some resizing? And what would be the best capture format after seeing those images (some are text better and others lines better)?
How does the DVD (or VHS) player display these pixels? When writing to DVD will 720 resized to 704 or 702 and will these be stretched to get 720 pixels? Because anyone says that I just have to capture at 720 and burn it to DVD, but will these be stretched again then if it would not be shrinked to 704 or 702 (I assume it is somewhere stored in 702 or 704 format thus 1 pixel width)?
And when creating an AVI-file, would you create 3 PC pixels to fit in a DVD pixel for example (which has been 1 but now stretched to 3 because of the 13.5 mhz clock for example)? So you will retain the wide format? or will you resize by 1/3 so s stretched DVD pixel of 3 PC pixels will be 1 PC pixel?
I've read a lot of things about pixel aspect ratio etc but I somehow still missing the last step in this think process.
Thank you for your help.