No letterboxing for widescreen source?

Devlin · 22nd August 2008, 01:19

I'm sure this is something idiotically simple, so I apologize if my thickheadedness offends you.

If I've got a widescreen source (720 x 480) that I'm going to encode to MPEG-2 with TMPG, should it bother me that the final result is not letterboxed on a 4:3 television?

Right now I have two CRT TV's, one a 1080i Sony. Both are 4:3 ratio (I will be replacing the std def set with a 1080p widescreen soon tho).

When I encode the 720 x 480 source, TMPG's main Settings screen defaults to say that it's for a 4:3 ratio (fine ATM, but maybe not for the future widescreen?). The advanced settings screen says that the source aspect ratio is "4:3 (704 x 480)", and that the output will be Full Screen (aspect ratio maintained).

Now I've been leaving all these aspect settings as-is, and the result after burning is a DVD video that fills the entire 4:3 screen (no black bars). It looks okay, but isn't this compressing or chopping off the video some? The resulting MPG has black bars when played on the computer, but they seem to vanish when it gets burned to the DVD. I've tried substituting 16:9 settings in the above places (as well as 1:1 VGA), but the results are the same.

What's happening here? Are black bars the result of a hidden flag that I've not / can't set? I can certainly resize a video and add black bars manually, which might be my best option.

Quick second question: Although the main settings screen almost always says 'interlaced', I find changing that to 'non-interlaced' yields better results. Am I imagining that?

Thanks for your help!

Dev

Devlin · 22nd August 2008, 03:06

I think I'm confusing the 720 x 480 with the 16:9 aspect ratio.

czerro · 4th September 2008, 05:25

DVD's allow you to assign an aspect ratio to the video data during encoding. Any DVD/MPEG-2 encoding software will have an option to set the desired Display Aspect Ratio. Some software simply refers to it as DAR. Obviously the video source is widescreen, yet the PAR (pixel aspect ratio) for any DVD is 720x480 (which is 4:3 and not 16:9). The DAR information is contained in the header (i believe) of the MPEG-2 stream. If you would like to avoid re-encoding the stream simply to assign a different DAR, I believe there is software to help with this. I remember a program called Restream ( I think) which was useful for tasks like this.

22nd August 2008, 01:19	#1 \| Link
Devlin Registered User Join Date: Jan 2007 Posts: 7	No letterboxing for widescreen source? I'm sure this is something idiotically simple, so I apologize if my thickheadedness offends you. If I've got a widescreen source (720 x 480) that I'm going to encode to MPEG-2 with TMPG, should it bother me that the final result is not letterboxed on a 4:3 television? Right now I have two CRT TV's, one a 1080i Sony. Both are 4:3 ratio (I will be replacing the std def set with a 1080p widescreen soon tho). When I encode the 720 x 480 source, TMPG's main Settings screen defaults to say that it's for a 4:3 ratio (fine ATM, but maybe not for the future widescreen?). The advanced settings screen says that the source aspect ratio is "4:3 (704 x 480)", and that the output will be Full Screen (aspect ratio maintained). Now I've been leaving all these aspect settings as-is, and the result after burning is a DVD video that fills the entire 4:3 screen (no black bars). It looks okay, but isn't this compressing or chopping off the video some? The resulting MPG has black bars when played on the computer, but they seem to vanish when it gets burned to the DVD. I've tried substituting 16:9 settings in the above places (as well as 1:1 VGA), but the results are the same. What's happening here? Are black bars the result of a hidden flag that I've not / can't set? I can certainly resize a video and add black bars manually, which might be my best option. Quick second question: Although the main settings screen almost always says 'interlaced', I find changing that to 'non-interlaced' yields better results. Am I imagining that? Thanks for your help! Dev Last edited by Devlin; 22nd August 2008 at 01:40. Reason: clarification

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22nd August 2008, 03:06	#2 \| Link
Devlin Registered User Join Date: Jan 2007 Posts: 7	I think I'm confusing the 720 x 480 with the 16:9 aspect ratio.

4th September 2008, 05:25	#3 \| Link
czerro Registered User Join Date: Feb 2008 Posts: 31	DVD's allow you to assign an aspect ratio to the video data during encoding. Any DVD/MPEG-2 encoding software will have an option to set the desired Display Aspect Ratio. Some software simply refers to it as DAR. Obviously the video source is widescreen, yet the PAR (pixel aspect ratio) for any DVD is 720x480 (which is 4:3 and not 16:9). The DAR information is contained in the header (i believe) of the MPEG-2 stream. If you would like to avoid re-encoding the stream simply to assign a different DAR, I believe there is software to help with this. I remember a program called Restream ( I think) which was useful for tasks like this.