Why do some of my conversions scale on my display, others don't?

[tonyp2]

I'm gradually trying to convert everything I own to hard disk based servers, connected by Ethernet to my DLNA compliant display and served by WMP12. It all works, but my DVDs which I've ripped to disk seem to scale properly on the display while my AVI captures (from VHS tapes through my Canopus ADVC110) converted to MPEG2 do not.

The DVD rips are typically 640x352 or something like that, and to date I've done these in XVid / MPEG-4. The VHS transfers are 720x480 SD MPEG-2. I have the standard NTSC template selected in Vegas Pro when doing these conversions. When I use the Auto screen size selection on my plasma display the DVD rips scale fine, but the MPEG-2 sources stay locked in their 720x480 format. I have to force the Wide selection to get these to scale to the parameters of the display.

I haven't done too many of these yet, so if there's a different way to do this through Vegas to fix this issue I'll happily re-do what I've done so far.

[guns1inger]

My guess - and this is just a guess at this stage - is that your mpeg-2 video has been encoded with a 4:3 flag, but your discs are authored widescreen, so the IFO files contain a 16:9 settings. When the player sees the DVD, it reads the IFO, and displays 16:9 as requested. When it plays the raw mpeg-2 files, it sees a 4:3 flag, and plays as requested. A simple way to test this theory is to use DVD Patcher to change the AR flag int he mpeg-2 files to 16:9, and try again.

Or it could be as simple as the fact that WMP has always had a dubious relationship with AR flags, and is simply ignoring the flag in your mpeg-2 files.

[tonyp2]

Hmm, you may be on to something guns. There's a setting in Vegas to render for 16:9 playback in the NTSC Customization panels. I wonder if that's what sets the flag. I thought that setting re-rendered the actual video content for 16:9. Is there a way to tell if the 16:9 settings are set in the MPEG-2 IFO?

[guns1inger]

You can use g-spot or mediainfo to tell you if the mpeg-2 Aspect Ratio flag is set to 4:3 or 16:9. The IFO file is a text file that is part of the DVD structure. You can check the content of the IFO file with IFOEdit or PGCEdit, and if necessary, alter it. In the render settings of Vegas you are setting the aspect ratio for the video you are encoding.

[tonyp2]

You can use g-spot or mediainfo to tell you if the mpeg-2 Aspect Ratio flag is set to 4:3 or 16:9. The IFO file is a text file that is part of the DVD structure. You can check the content of the IFO file with IFOEdit or PGCEdit, and if necessary, alter it. In the render settings of Vegas you are setting the aspect ratio for the video you are encoding.

Okay. I have Gspot and IFOEdit on the system so I'll check when I get home.

If I understand the last sentence I guess I should ask then how would I include the 16:9 flag as part of a 720x480 rendering in Vegas?

[tonyp2]

The IFO file is a text file that is part of the DVD structure. You can check the content of the IFO file with IFOEdit or PGCEdit, and if necessary, alter it.

This is not going to be as easy as I thought, at least not with Restream. These files are already mux'd. I can only change the flag if the video file is demuxed.

[guns1inger]

Did I say restream ? I said DVD Patcher, which can work with muxed files.

[tonyp2]

No, you didn't. I did a quick read on the download page and it said that Restream was an alternative tool. Since I already had it I thought I'd give it a try. I'm getting DVD Patcher now.

For a job like this on a mux'd file do I have to do the whole thing or just the first header?

[guns1inger]

I prefer to do the whole thing. DVD Patcher only takes a minute or so, and can patch the file in-situ, so you don't end up with extra copies etc.

[tonyp2]

Ran DVD Patcher. Sure enough it worked the way you said. Just because I'm curious I also reran a Vegas rendering with the display target set to 16:9. I want to see what the difference is between the two (had to run that overnight and haven't looked at it yet). Does DVD Patcher use the same 1.212 pixel AR as Vegas? If all this does is set a flag (even though I did it via re-rendering in Vegas) should I be right in assuming there should be no difference in the quality of the output?

[tonyp2]

I have come to the conclusion that it's better to leave my conversions at 720x480 NTSC and force the display to one of its "gradual" widescreen modes for this material. Using either DVD Patcher or rendering this content to fit a WS display in Vegas produced the same effect - exagerrated widening of the entire image. With one of the custom WS modes selectable from the display I can create that sort of gradual widening to fill the 16:9 shape without too much distortion in the center area, I guess I was hoping for too much to be able to do the conversion in a way that would automatically drop into that mode upon detection of the content type. It does this with NTSC aspected DVDs.

[guns1inger]

You are doing something wrong in Vegas if you are getting distorted output. Either the project settings are wrong, or you are doing manual adjustments incorrectly. DVD only supports 4:3 or 16:9, so you have to set your project to one of these, and work consistently in that mode.

[tonyp2]

That's quite possible. I have to keep poking around with it I guess.