DVD/Widescreen question.

[Andreas Fernbrant]

Ok, I don't really know how to put this questions I can't even figure out how to ask it in my native language.

I will try and if you don't understand I will try to put the question in another way.

I'm making a extremesports gymnastic/acrobatic DVD and I'm playing around with the 16:9 and 4:3 format. When I capture widescreen video it has the same ratio, 720x576 (PAL) but diffrent pixel aspect ratio then ordinary 4:3 video have. (so it looked squashed. No problem with that, Because when I load it in to Premere or Vegas it converts it so that it looks okay. I figured if I send that squashed signal to a television, (4:3) what would happen? So I borrowed a 4:3 television and hooked it up, Yup! as I thought.. the picture was squashed. So I now know that if you send a widescreen signal to a 4:3 television it still squashes the image. I don't get the black borders up and down. Is this because the pixel aspect ratio? If I'm not able to use the "widescreen" feature in Premiere or Vegas and render it out to a 4:3 tv with border and fullscreen on a widescreen television, why do the programs have the feature? Do I have to render the borders manually? So the actual file has the black saved as information? What if I render the file as a 16:9 format? like 720x405? (or what the correct format would be?) What would happen then? If I put a DVD disc in my dvd player it gives me black borders up and down on my television. Great! If I put it in my computer I see a videofile with a widescreen/cinemascope ratio and no renderd black bars up and down? What happens if you shoot 16:9 on your camera and hooks it up to a 4:3 television? Correct ratio (borders) or squashed?

So my question comes down to this, What is the correct way to get widescreen format on a widescreen tv and borders on a 4:3 tv? To render them out (borders) or to stick with the "squashed widescreen" because the dvd player gives it the correct ratio?
(and it's my editing soultion that tricks me)

My last question, When you open a dvd in your computer, it has a higher resolution then dv. I mean the DVD are higher then 720 (standard DV) Yeah I know the diffrence and I know why and what. What I don't know is why they do the DVD with that higher resolution.

Well, this message took me a lot of time to write but I don't know if someone will understand my questions. I have a really hard time to explain my problem.

/Andreas

[Ed Smith]

I'll have a go at answering the question.

I think your question has been answered many times, do a search for wide screen or something similar. But its something like this.

When you shoot in 16x9 on the camera it vertically squishes the footage so when viewed on a 4x3 TV the footage will look squashed. Some 4x3 TV's have a button which you press so it squishes the footage into the correct aspect ratio and you get the black bars top and bottom. When you view the footage on a 16x9 TV there is no bars and the picture looks normal i.e. in the correct 16x9 aspect ratio.

DVD Players and Digi boxes automatically compress the footage (unless you have told it other-wise) so your 16x9 footage shot with the camera and then burnt to DVD will have the correct aspect ratio. So if played on a 4x3 TV you will get the black bars if played on a 16x9 TV you will get a 16x9 picture.

For DVDs stay with the squished effect, 16x9 because:
A) Most TVs now a day are 16x9
B) Most of the newer 4x3 TVs have a 16x9 squished button
C) The DVD player will output correctly to 16x9 on a 4x3 TV and 16x9 TV

Hope this helps,

Ed Smith

[Andreas Fernbrant]

Ed, I have to thank you.. Great answer... I now know exactly how it works thanks to you!

I have some follow up questions,

My video sometimes get jaggy, (not interlaced) If I code mpeg2 files even though I apply interlace. Or I should not interlace when I output it... because if I interlace in my mpeg2 codec and then play it on a DVD it interlace it back?

I heard somewhere DVD play back video progressive?

Sometimes my video gets "laggy and chopply" (almost like a very low frame rate) Why is this?

Thanks!

/Andy

[Rob Lohman]

If your footage is interlaced you should tell your MPEG2 encoder
this. It needs this information to correctly construct the MPEG2
file.

The DVD players will change certain things also on this information.
And no, most DVD players do NOT play back progressive because
most TV's don't understand it. BUT, almost all hollywood produced
DVD's are progressive and this signal is just passed along to the
TV. The only place where a DVD player has to do something if
you always want progressive is when the DVD is interlaced. The
DVD player must then de-interlace it to remove interlacing jaggies.

When you encode MPEG2 and author a DVD you can tell it that
your footage is in 16:9 format. This will change a bit on the DVD
indicating to the player that this disc is in anamorphic resolution.
The DVD player will do the following depending on how it is
configured by the end user (a DVD Player does NOT know which
format a TV is that you have connected!!):

1. the user has selected 16:9 TV: the DVD player leaves the
material alone and sends it straight to your TV. It assumes the
TV knows how to handle anamorphic footage. If it doesn't know
this you will see squashed footage, otherwise it will look okay.

2. the user has selected 4:3 TV: the DVD player will unsquash
and resize your footage while at the same time adding black
bars for you. The result is send to your TV and will look okay
on all TV's (but with less resolution on a 16:9 TV)

I hope this explains it a bit more....