Confused about D1/D2 (1/2 D1) resolution encoding

[Shudder]

Ok, got a quick question.. searching for D1 or d2 or such is difficult since it's such a small word..

I encoded a tv show (probably around 640x480) to D1 (720x480) and it looked good. Did it in D2 resolution and it still looked fine. What's the deal?

I'm mainly curious how the vertical resolution can stay the same but the horizontal is cut in half. That and if I encoded at say 3200 for the bitrate, would I be wasting a ton if I kept it at 720.. would it make things so much worse to double the hor. resolution? I haven't yet made a DVD to see if it looks bad on my TV, but I'm hoping it'll be fine. Thanks

[andkiich]

In a nutshell, 1/2D1 will look better at a lower bitrate than full D1. If I'm encoding MPEG2 and my bitrate falls around 3000, then I'm using 1/2D1. Anything above that and I'm using full D1, unless the source is VHS, then it's 1/2D1(due to source resolution).

Will the file size between the 2 resolutions with the same bitrate be different? No. Would most people be able to tell a difference in video quality? Depends on how they see things and what type of TV they are viewing the DVD on. Smaller tubes are more forgiving than larger tubes and projection TVs.

Through experience, and some technical knowledge, you'll learn to use the proper settings that give what you perceive to be the best quality.

[DaveS]

I thought 1/2 D1 wasn't actually in the DVD spec (??)..my only hesitation is using it for others...maybe it is part of the official spec for DVD?

[teegee420]

1/2 D1 is DVD spec. Click on the "What Is DVDR" link in the upper left corner of this page for more info.

[Shudder]

So is 3100 for the bitrate a bit overkill for 1/2 D1 for 3 hours of video (again, 183MB 640x480 xvid source - good quality) or should I go back to D1 for such a "decent" bitrate?

Or just say F it, keep what I've encoded, and stop crying?

[teegee420]

So is 3100 for the bitrate a bit overkill for 1/2 D1 for 3 hours of video (again, 183MB 640x480 xvid source - good quality) or should I go back to D1 for such a "decent" bitrate?

That's a decent bitrate for 1/2 D1. Certainly not overkill because it is generally believed that 5000kbps is the max bitrate that can be utilized for 1/2 D1. If your movie doesn't have a tremendous amount of fast-moving action scenes I think it will look decent at 3100.

Or just say F it, keep what I've encoded, and stop crying?

There are probably a few people who might tell you that, but I'm not one of them. Good luck.

[Shudder]

Thanks for the help. I'll probably just keep it at 1/2 D1 (still don't understand how it just halves the x res) and if I'm not happy with it, there's always friends to give them away to. It's just that for the best show ever (Arrested Development) it deserves the best quality it can get at 8 episodes a disc

[DaveS]

1/2 D1 is DVD spec. Click on the "What Is DVDR" link in the upper left corner of this page for more info.

thanks - in fact my set top does 1/2 D1 - I just wasn't sure if it was a common format or actually in the spec...should have checked the link first ...