View Full Version : How do you make a widescreen DVD out of 16:9 material?


Sami Sanpakkila
January 23rd, 2008, 06:11 PM
Hi,

Im shooting a music video tomorrow and the end product will be a widescreen DVD. But as I have just learned widescreen DVD's are not really 16:9!?!? I tried rendering a DVD out of 720p material I shot with EX1 and it leaves small black bars on left and right of the image.

What aspect ratio is DVD actually? And if I choose different aspect marker from EX1 is there one accurate with a widescreen DVD's actual aspect ratio? 15:9? Would I have to resize the picture in post though?

How do people do DVD's with material shot in 16:9 with EX1?

Thanks,

Sami

Matthew Scott
January 23rd, 2008, 08:21 PM
SD dvd's (wide ones) have an aspect ratio of 16:9. The frame size for the encoded Mpeg 2 is 720x576 (PAL) and 720x480 (NTSC I think) Because the pixels are elongated, they fill up a "wide" screen.

If you are creating a wide screen PAL SD dvd - from ANY video (doesn't matter what camera, as long as it was shot in 16:9) - the resulting movie file should be as follows:

File format - mpeg2
Aspect ratio - 16:9
Frame size - 720x576
Bitrate encoding - 7000bps is a safe bet if the footageis half an hour or so.

Good luck, and do some searching on how to create a dvd :)

Ray Bell
January 23rd, 2008, 09:17 PM
Sounds like Matts got you going in the write direction....

Although this site I'm going to point you towards is for users of Cineform there is some good info you might pick up from the directions....

http://supportcenteronline.com/ics/support/default.asp?deptID=614

Eric Darling
January 23rd, 2008, 09:58 PM
Widescreen DVDs are 16:9. What DVD authoring software are you using? That's where the flag gets set for 16:9 vs. 4:3. If you're experiencing side crop issues on footage that originated as 16:9, and you've output an anamorphic 720x480 (NTSC) movie, something else is going on to mess with the aspect ratio.

Sami Sanpakkila
January 24th, 2008, 03:54 AM
Hmmm... Weird. Ive shot with EX1 in 720p 25fps. And Im using Vegas Pro 8 to render to DVD Architect. Ill do some test with it saturday after I come back from the shoot.

Thanks guys!

Sami

Paul Kellett
January 24th, 2008, 05:17 AM
I use the EX1 and vegas pro 8.What template are you using ? Explain to me what boxes are ticked in the template and sizes in boxes and i'll tell you what's wrong.
Paul.

Bob Grant
January 24th, 2008, 06:52 AM
There is a very small difference in aspect ratio between 16:9 HD and 16:9 SD.

HD is 1.777:1 (1920x1080) and SD is 1.821:1 (1049x576 in PAL). That's all in square pixels.

So when you downscale HD to 16:9 SD you get small black bars. If they're anything more than a few pixels wide then you have a different problem. I think for SD on any monitor they'll be masked off however if that does cause you concern then it's easy enough to fix in Vegas and I assume any other NLE. In Vegas tick the checkbox "Stretch Video to Fill Output Frame Size (do not letterbox)" in the Render As dialogue box.

The above fix will very, very slightly stretch the image. If that concerns you then you could crop the image to match the output aspect ratio.

Sami Sanpakkila
January 25th, 2008, 02:56 PM
(sorry if this is getting to go off the EX1 forum a bit, thank you for your help!)

My project in Vegas is HD 1280x720 25p. I try to use Mainconcept MPEG-2 using DVD architect PAL Widescreen video stream template.

The black bars on left and right are very small so it must be the issue Bob Grant mentioned (Thanks Bob!). I'm used to making SD DVD's but I was totally unaware that the 16:9 is different in HD.

Can I change the Field order in the template to progressive. Now the DVD architect PAL Widescreen is default at lower field first. I want to keep the footage progressive. Will this be a problem with dvd players or televisions or...?

And the aspect ratio is default as 16:9 display, should I change it to square pixels? I understand other display options but what does this option look like in a widescreen tv and in a normal 4:3 tv?

Sami

Peter Kraft
January 25th, 2008, 03:43 PM
Sami,
I'd neither stretch nor cropp as both methods potentially introduce a picture less sharp then the original. IMHO stay with the original frame size and live with the small black bars on both sides of the picture. On a normal TV set you won't be able to see them anyhow. On an LCD or plasma screen people should not take notice of them ('cause the picture is so sharp).

Bob Grant
January 25th, 2008, 03:53 PM
Sami,
the DVD spec doesn't allow for 25p. If you keep everything progressive you'll get 25PsF in your video and shouldn't have any interlace artifacts however you're kind of at the mercy of what the TV might decide to do. Obviously it can't create interlace combing but watch your vertical rsolution. If it's too high you can get aliasing or line twitter on some displays that'll 'bob' your video. One way to check is to use VLC to playout the DVD and switch de-interlace methods to see all possible outcomes.
Although this doesn't directly relate to the EX1 it does relate to all HD cameras, especially if they shoot progressive. We've had people heaping all manner of blame on cameras due to how the downscaled SD looks when it wasn't a camera problem at all, it was a display device problem. Unfortunately we can't control what our viewers watch our product on so we're sometimes forced to deal with the images to avoid the problems.