SD widescreen size at DVinfo.net

Dave Campbell · January 10th, 2007, 08:19 PM

So, trying to use virtualdub to take my 1920x1080 project and make it a widescreen SD avi.

So, I assume the 720x480 is for 4by3. So, what do I use for widescreen?

Thanks

Dave

Boyd Ostroff · January 10th, 2007, 08:51 PM

I don't know anything about Cineform so maybe I don't understand the question. However, if you're showing widescreen SD on a video monitor it is still 720x480. The display device itself needs to stretch the image to the correct proportions based on its native pixel aspect ratio.

If you are going to display it on a computer monitor with square pixels then it's just simple math. You have 480 scan lines so the calculation is 480 x 16 / 9 = 854 (rounded up the the nearest pixel). In other words, the frame size would be 854 x 480.

Devon Lyon · January 10th, 2007, 09:28 PM

Dave,
I understand what you are asking, as I've had a similar question.
What is the pixel aspect ratio of your 1920x1080?
Also, do you own After Effects?

Dave Campbell · January 10th, 2007, 10:03 PM

So, I need to make copies of this christmas family video for friends and family. So, I assume it will be shown on various TV screens. I want it to be widescreen SD. (I would have just used CFHD but I have yet to get it to work on my project.)

So, I had read the 16/9 and used the 854X480. So, I did a little clip like this from VB, and the specs on the avi were 854x480, 1.0 pixel size. This is where I am really confused.

HDV is 1440x1080, PS of 1.33333
SD is I thought was 720x480, ps of .9
My Propect 10 bit is 1920x1080, ps of 1.2 (?)

When I pulled the 854x480 into a Ppro WS SD project, it seemed to show a little bit of black bars on the side.

So Boyd, is the size 854x480 for TV?

So much to learn.

Thanks

Dave

David Newman · January 10th, 2007, 10:50 PM

SD DVD is always 720x480 for both wide and standard, it just depends on the shape of the source pixels you jam in to that tiny image. 1920x1080 is square pixel 1.0 16x9, so if you resize that to 720x480 in VirtualDub you with get widescreen SD with a 1.2 pixel aspect ratio. Now VirtualDub likely won't set the pixel aspect in the AVI header, so desktop playback may look wrong, but put that file in a DVD Authoring package set to 16x9 and your DVD will encode correctly.

Dave Campbell · January 11th, 2007, 10:10 AM

Thanks David, will try take since when I used VD with 720X480, it seemed to chop the sides, and the pixel size said 1.0

Will try again tonight

Dave

Dave Campbell · January 15th, 2007, 12:06 PM

David, if I take my VD output, and put it into Premiere 16x9 project, it says it is 720x480, and pixels are 0.9.

But, if I then take this avi, and use TMPGNEC with 16x9 output for mpeg encoding, this output file is correct being 16x9 when I watch it.

Now, if I import this mv2 output file into PPro, it says its a 720x480 1.2 pixels
and is a correct 16x9 format.

So, how does the average person know this will happen? I sure did not, and it makes no sense to me, yet. :o(

Dave

January 10th, 2007, 08:19 PM	#1
Dave Campbell Major Player Join Date: Aug 2003 Posts: 568	SD widescreen size So, trying to use virtualdub to take my 1920x1080 project and make it a widescreen SD avi. So, I assume the 720x480 is for 4by3. So, what do I use for widescreen? Thanks Dave

January 10th, 2007, 09:28 PM	#3
Devon Lyon Major Player Join Date: May 2005 Location: Oregon Posts: 213	Dave, I understand what you are asking, as I've had a similar question. What is the pixel aspect ratio of your 1920x1080? Also, do you own After Effects? __________________ Lyon Films www.LyonFilms.com;

January 10th, 2007, 10:50 PM	#5
David Newman CTO, CineForm Inc. Join Date: Jul 2003 Location: Cardiff-by-the-Sea, California Posts: 8,095	SD DVD is always 720x480 for both wide and standard, it just depends on the shape of the source pixels you jam in to that tiny image. 1920x1080 is square pixel 1.0 16x9, so if you resize that to 720x480 in VirtualDub you with get widescreen SD with a 1.2 pixel aspect ratio. Now VirtualDub likely won't set the pixel aspect in the AVI header, so desktop playback may look wrong, but put that file in a DVD Authoring package set to 16x9 and your DVD will encode correctly. __________________ David Newman -- web: www.gopro.com blog: cineform.blogspot.com -- twitter: twitter.com/David_Newman

January 10th, 2007, 08:51 PM	#2
Boyd Ostroff Wrangler Join Date: Dec 2002 Location: Mays Landing, NJ Posts: 11,802	I don't know anything about Cineform so maybe I don't understand the question. However, if you're showing widescreen SD on a video monitor it is still 720x480. The display device itself needs to stretch the image to the correct proportions based on its native pixel aspect ratio. If you are going to display it on a computer monitor with square pixels then it's just simple math. You have 480 scan lines so the calculation is 480 x 16 / 9 = 854 (rounded up the the nearest pixel). In other words, the frame size would be 854 x 480.

January 10th, 2007, 10:03 PM	#4
Dave Campbell Major Player Join Date: Aug 2003 Posts: 568	So, I need to make copies of this christmas family video for friends and family. So, I assume it will be shown on various TV screens. I want it to be widescreen SD. (I would have just used CFHD but I have yet to get it to work on my project.) So, I had read the 16/9 and used the 854X480. So, I did a little clip like this from VB, and the specs on the avi were 854x480, 1.0 pixel size. This is where I am really confused. HDV is 1440x1080, PS of 1.33333 SD is I thought was 720x480, ps of .9 My Propect 10 bit is 1920x1080, ps of 1.2 (?) When I pulled the 854x480 into a Ppro WS SD project, it seemed to show a little bit of black bars on the side. So Boyd, is the size 854x480 for TV? So much to learn. Thanks Dave

January 11th, 2007, 10:10 AM	#6
Dave Campbell Major Player Join Date: Aug 2003 Posts: 568	Thanks David, will try take since when I used VD with 720X480, it seemed to chop the sides, and the pixel size said 1.0 Will try again tonight Dave

January 15th, 2007, 12:06 PM	#7
Dave Campbell Major Player Join Date: Aug 2003 Posts: 568	David, if I take my VD output, and put it into Premiere 16x9 project, it says it is 720x480, and pixels are 0.9. But, if I then take this avi, and use TMPGNEC with 16x9 output for mpeg encoding, this output file is correct being 16x9 when I watch it. Now, if I import this mv2 output file into PPro, it says its a 720x480 1.2 pixels and is a correct 16x9 format. So, how does the average person know this will happen? I sure did not, and it makes no sense to me, yet. :o( Dave