vertical resolution of anamorphic widescreen?

[Sean_ve99]

Hi
Can anybody help me, I got confused.
How much is vertical resolution of anamorphic widescreen video in 4:3 TVs? And how much is vertical resolution of non anamorphic video in 4:3 TVs? How do you calculate it?
I greatly appreciate any help in advance.

[Pinstripes23]

They are both the same for Full D1 DVD - 480 (NTSC) or 576 (PAL). It's how they are encoded that determines the aspect ratio - 4:3 or 16:9. To calculate the easiest is to use fitcd. For those that fully understand the concept can actually use a calculator or maybe eyeballing it. What kind of files are your sources?

[Sean_ve99]

Sorry I forgot to mention that when video Aspect is 1.85:1, thanks

[Sean_ve99]

Thanks for the help but it is not my answer, I am looking for a way to figure out the true Width and height of image resolution, I know true resolution of anamorphic video in 16:9 TV is 854x480 (480x1.78=854) if Aspect ratio is 1.85, it would be 854/1.85=461 but I am not sure about true height of anamorphic video in 4:3 TV and also wants to know about true height of Nan-anamorphic video in 4:3 TVs. Thanks

[JohnnyMalaria]

The "true" resolution of 4:3 NTSC is 4 x 480 / 3 by 480. i.e., 640 x 480 (no coincidence that this is the same as VGA). Likewise, 16:9 is 16 x 480 / 9 by 480 (853.3333 x 480).

I don't understand the question about the height of non-anamorphic video in 4:3 TVs. Standard def 4:3 TVs are all 480 (NTSC) or 576 (PAL) vertically.

[jagabo]

640/1.85 = 345

When viewed on a 4:3 NTSC SD TV the height of a 1.85:1 movie will be 345 lines.

[JohnnyMalaria]

Sorry - I agree with the 345 lines. I should have clarified that a standard def TV always scans 480 or 576 lines (active) but the widget feeding the TV will create a signal having the necessary number of black lines above and below the central region of interest. i.e., no standard def TVs scan just the middle portion of lines. I've used some SD NTSC monitors that have enough range in their vertical size adjustment that you can make the full 480 line image appear 16:9. I'm cheap that way!

[jagabo]

For PAL it's 768/1.85 = 415.

Where to 640 and 768 come from?

NTSC TV is always 480 scan lines high. The screen's aspect ratio is 4:3. So the width is equivalent to 480 * 4 / 3 = 640 pixels.

PAL TV is 576 scan lines high. 576 * 4 / 3 = 768.

[Sean_ve99]

Jagabo, are you going to say that both anamorphic and non-anamorphic true height in 4:3 TV would be 345 lines? No difference? You mean true resolution of anamorphic video in standard TV would be 640x345 while it is the same for non-anamorphic?

[jagabo]

You mean true resolution of anamorphic video in standard TV would be 640x345 while it is the same for non-anamorphic?

Yes. Unless you use pan-and-scan or zoom modes.

[Sean_ve99]

Thanks, I just wasn’t sure about it. But what about vertical lines for widescreen video 1.85 in 16:9TVs? Is it 461 lines? (854/1.85=461) if yes, why some anamorphic DVD with 1.85 aspect ratio fill 16:9 TV frame completely and they don’t use letterbox while there are 19 lines mixing.

[jagabo]

With a non-upscaling player connected via HDMI the 720x480 frame is sent to the TV. The TV scales that to it's native resolution and displays it. An upscaling DVD player will upscale the 720x480 frame to either 1280x720 or 1920x1080 then send that to the TV. The TV will then upcale or downscale to its native resolution and display the picture.

But yes, A 1.85:1 movie on a 1.78:1 anamorphic DVD should only occupy about 461 lines of the 720x480 frame. The extra 19 lines are small enough to be hidden by the TV's overscan simulation. Most HDTVs simulate overscan and hide about 3 percent on each edge of the picture. Some DVDs may assume 1.85 is close enough to 1.78 and just squeeze the full frame into 720x480, or zoom slightly and crop the edges.

[Sean_ve99]

Yes, it is right, thanks for your explanation.