In addition to creating or copying DVD’s, the other useful application of DVD-R is to record NTSC sources in the USA, Canada, and several other countries that support it. The National Television Standards Committee established this interlaced standard in the 1940's and modified it in 1953 with the advent of color television. It uses 525 lines of horizontal video which is written 262.5 lines in one pass and 59.94 seconds later, the gaps are filled in. The horizontal rate is 15,734 Hz and the vertical rate is 59.94 Hz and both signals are transmitted by a television station or generated in a settop DVD player or in a computer TV out card.
NTSC video is displayed, from the perspective of computer pixels, with a horizontal display of about 633 pixels and vertical of about 430. The remaining information at the top and bottom of the screen is not visible to the human eye and contains teletext information and other coded data.. A VCR actually displays fewer vertical pixels, more on the order of 360 pixels from a resolution standpoint. From a video capture standpoint, capturing video at 640X480 is ideal
since all of the information from NTSC will be available without wasting disc space by capturing
at a higher resolution.