What is D1 or D2?

[jfharper]

Could someone tell me what these are and the difference between D1 and D2 is?
Thanks,
JH

[rhegedus]

I think you're talking about dimensions of screen resolution i.e. D1 x D2 (horizontal x vertical).

[johns0]

If i think what you are asking d1 is 720(704)x480/576 and d2(d1/2) is 352x480/576 which are dvd resolution sizes,one full and the other 1/2 dvd.

[rhegedus]

Just read the glossary https://www.videohelp.com/glossary#D1

D1
A video resolution standard. In the NTSC system, "Full D1" means 720x480 pixels, and in the PAL and SECAM systems full D1 is 720x576. You also see "cropped D1", which is 704xNN, which is useful because the 8 pixels on either edge of the video frame aren't supposed to contain useful information. Therefore, some programs will prefer the cropped D1 resolution to save bandwidth. Other popular resolutions are often described in terms of D1: the SVCD resolution is 2/3 D1 (480xNN) and 352xNN is 1/2 D1. Occasionally you see SIF somewhat inaccurately described as 1/4 D1. videographica

I'm unsure as to whether D2 means half D1, or whether D2 is the vertical resolution since this https://www.videohelp.com/glossary#Half%20D1 implies D1 is the horizontal resolution.

Half D1
An MPEG-2 video encoding mode in which half the horizontal resolution is sampled (352x480 for NTSC, 352x576 for PAL). See also D1

[jfharper]

Thanks for the reply...I'll be sure to check the glossary next time...didn't see it as of yet.
JH