Maximizing HD to SD Quality

[Perrone Ford]

Originally Posted by Martin Wiosna

and so far everyone is happy (including me because I spend less time on a project)

Am I missing something here?

If you and your clients are happy, then no you are not missing anything. However, it is not the goal of everyone to produce faster results, or take shortcuts. Some people strive for excellence. Others don't.

[Ken Diewert]

Can someone share there virtual dub 'resize' and compression settings. While I'm rendering a very nice looking avi. DVDA does not like it at all and is really messing it up. The aspect ratio is off (vertically squished), and has horizontal lines.

The source clip is:

1440x180 (cineform .avi). Vegas project settings: HDV 1080-60i template - Upper field first, blend fields, 8-bit. Note: source footage is mixed hdv and 5d2 (cineform converted via Neoscene)

The vdub settings i'm using are:

Resize
Absolute pixels: (checked) set at 720x480
Relative:(unchecked) 50x44.4444

Aspect Ratio: Disabled
Filter Mode: Lanczos3

Interlace: (unchecked)
Framing Options: Letterox/crop to size: 720x480
Codec friendly sizing: have tried several - soesn't seem to matter.


I have also reloaded the .avi into Vegas. (widescreen project settings) and re-rendered using mpeg2 template and the re-rendered file , and while it looks good, the aspect ratio (vertical squishing) is happening again.

Any help would be appreciated.

Ken.

[Richard Hunter]

Hi Ken. I don't see the Letterbox/Crop to Size setting in my version of Vdub, but I don't think you should be setting anything that says letterbox.

Alternatively, are you setting up a 16:9 project in DVDA? Sounds like it could be your project is 4:3 and the footage is 16:9, hence the letterboxing.

Richard

[Mark Howells]

[QUOTE=Jim Snow;1227673]

My conclusion is that most of the “damage” to resolution is when the files are resized when encoding with Main Concepts. The files that I encoded to MPEG-2 after resizing them in VirtualDub were of apparently equal quality when encoded with either the Main Concepts encoder or TMPGEnc. It appears that the culprit that degrades the files is the resizing operation in Main Concepts.

If the culprit is the resizing operation in Main Concept would a simple solution be to render your edited HDV footage as uncompressed SD avi in Vegas (ie resize). Then render this avi file to mpeg2 using mainconcept in Vegas. Or am I missing a vital point.

[Ron Evans]

Ken, this is what a lot of people on the EDius forum use. The Vdub resize will be the same for Vegas too.
Using Virtual Dub and Edius to downscale HD to SD.
My normal approach is to use TMPGenc with Lancsos first and if the results are OK then I am happy if there are problems then I use this Vdub approach. IT takes longer needs some touch up for colour and sharpness but has less artifacts. Most of the time TMPGenc is fine and a lot better than directly out of Vegas or Edius. I output from Edius as a HQ file or Vegas as HDV file and let TMPGenc do the downconvert and encode for SD DVD.

Ron Evans

[Ken Diewert]

Thanks Richard/Ron,

I just ran yet another test in vdub with the resize set to 720x405 (16:9 ratio) using Lagarith compressor - and it renders beautifully. DVDA then prepared and burned it in proper aspect ratio. WTF?

I'm going to try another larger file now.

[Jim Snow]

Originally Posted by Mark Howells

If the culprit is the resizing operation in Main Concept would a simple solution be to render your edited HDV footage as uncompressed SD avi in Vegas (ie resize). Then render this avi file to mpeg2 using mainconcept in Vegas. Or am I missing a vital point.

You would still have a resizing problem. The Lanczos3 resizer is important. It does a much better job.

[Ken Diewert]

Originally Posted by Ken Diewert

Thanks Richard/Ron,

I just ran yet another test in vdub with the resize set to 720x405 (16:9 ratio) using Lagarith compressor - and it renders beautifully. DVDA then prepared and burned it in proper aspect ratio. WTF?

I'm going to try another larger file now.

Well, I'm not exactly sure why, but that 720x405 setting works beautifully in DVDA

[Perrone Ford]

Originally Posted by Ken Diewert

Well, I'm not exactly sure why, but that 720x405 setting works beautifully in DVDA

Welcome to my workflow.

Lagarith + Lanczos = Beautiful downscales.

The 720x405 works fine for SD. It's a bit tricky for those with 16:9 TVs. 720x480 with the widescreen flag on should work fine for making SD discs and it's what I tend to do these days.

[Ken Diewert]

Perrone and others,

Thanks for all the help! That's the kind of DVD quality I was expecting from an HD-SD conversion.

[Mark Howells]

Hi,

When rendering the HQ AVI file from Vegas using the Lagarith codec, for importing into Virtualdub, do you set the aspect ratio as 1440:1080 with PAR at 1.333333 (ie same as source) or use custom setting 1920:1080 with PAR square pixels. Apologies if this is a basic question. I don't have Vegas in front of me.

[Perrone Ford]

I avoid non-square pixels like the plague. They complicate matters more than necessary. Once you get to square pixels everything becomes perfectly simple.

[Richard Hunter]

Originally Posted by Mark Howells

Hi,

When rendering the HQ AVI file from Vegas using the Lagarith codec, for importing into Virtualdub, do you set the aspect ratio as 1440:1080 with PAR at 1.333333 (ie same as source) or use custom setting 1920:1080 with PAR square pixels. Apologies if this is a basic question. I don't have Vegas in front of me.

I export out at 1440x1080, i.e. no change, so that VD can handle all the resizing. VD squashes the on-screen preview because it doesn't recognise the non-square pixels, but don't let this bother you, because you will get the correct geometry back after resizing to 720x480 and making a 16:9 DVD.

I certainly would not want to upsize to 1920x1080 just to resize back to SD resolution again.

Richard

[Perrone Ford]

Very true Richard, very true.

[John Peterson]

Perrone,

Are you shooting 1080/30p with your EX1 and creating interlaced SD DVDs from that or are you shooting 1080/60i?

Thanks,

John