Can someone EXPLAIN the whole "720x480" thing to me?

[manono]

Yeah, but I specifically mentioned DVD. I know nothing (and care even less) about what the broadcasters do.

don't know for sure but I'd bet most display scalers do the same.

If you're saying a DVD player and/or TV set will crop 8 off of each side before resizing to, say, 1440x1080 with pillarbars then, at least in my own case, I know that to be untrue.

[edDV]

Yeah, but I specifically mentioned DVD. I know nothing (and care even less) about what the broadcasters do.

don't know for sure but I'd bet most display scalers do the same.

If you're saying a DVD player and/or TV set will crop 8 off of each side before resizing to, say, 1440x1080 with pillarbars then, at least in my own case, I know that to be untrue.

I don't think DVD players do. The analog outputs seem to carry the full width.

But I wonder if all "wide" 720 pixels survive flat screen plasma or LCD-TV "just scan" modes. Almost all sets otherwise overscan H and V more than 16 horizontal pixels.

This calls for an appropriate test pattern.


PS: I see your point on 4x3 to pillarbox. I was thinking 16x9. I need to test that too.

[manono]

I don't think DVD players do.

Many DVD players - perhaps the majority of them out there - crop the image at least somewhat before sending it to the TV set.

Almost all sets otherwise overscan H and V more than 16 horizontal pixels.

Like I said, I can only speak for myself. My Sony Bravia 1080p set doesn't overscan at all and doesn't crop anything from the picture before resizing. I can prove that if jagabo would point me to his overscan picture. I tested it in my TV once and then posted the pic from a camera here, but I have no idea where that post is now.

[jagabo]

Here's a 720x480 crop test image. It's only marked to 20 pixels, not enough for overscan testing, but enough for testing DVD player cropping.



And a 704x480 version if you want to test that too.



I think I've done this test before and found that some DVD players cropped the 16 extra columns, some didn't.

[2Bdecided]

jagabo, are they yours, or copied? I have something similar on a test DVD.

On your 704x480 image, the scale on the right side it out by one pixel. What you've labelled 0 is actually 1.


On their SD analogue outputs, all the DVD players I've tested remove a little of the 720-pixel image, windowing it down to ITU/SMPTE width (approx).

On the BBC, their HD programmes (1440x1080) are resampled down to 720x576 to fill all pixels - so assuming 720 = 16x9 - i.e. incorrectly as far as most of us are concerned.

As you say edDV - you need to make sure everyone working on a project agrees on this!

Cheers,
David.

[jagabo]

jagabo, are they yours, or copied? I have something similar on a test DVD.

The 720x480 image was downloaded from somewhere long ago. I think I modified it a bit to suit my needs.

On your 704x480 image, the scale on the right side it out by one pixel. What you've labelled 0 is actually 1.

Thanks, I'll fix that.

[edDV]

My initial tests on the Vizios show near perfect edges in 16x9 Wide but in 4x3 pillarbox mode vertical is OK but horizontal is cropped over 20 pixels each side. There are many combinations of settings for the Phillips 5992 and TV. This will take some time but it is nice to have the chart.

[manono]

Here's mine using the 720x480 pic encoded as 4:3:



and as 16:9:



The DVD player is an Oppo DV-981HD. The TV is a Sony Bravia KDL-46VL130. That's what Costco called it. It's called something else most other places. They're connected via HDMI.

In case anyone wants to try this themselves to test for cropping and/or overscan, here's a link to an ISO of an NTSC DVD I made (4.3 MB):

http://www.mediafire.com/?mmmcy2mznno

There's a rudimentary menu with button links to the 4:3 and 16:9 versions of the picture, both of which play for 10 seconds. Use ImgBurn to burn it to DVD-RW, DVDR, or CD if your player can play Mini-DVDs.