HD downconvert to DVD problem

[Chris Hewitt]

Hi all,
I shoot 1080P/50 on a Panasonic AC160 and edit in Sony Vegas Pro 11 and it all looks great, especially on BR.
By the time I convert down to DVD however, things like trees, especially the leaves, shimmer like crazy...these are static shots (hand held) and then I put them through Mercali 2 to stabilize them.
Has anyone noticed any issues with software stabilizers? FWIW, the camera has OIS turned on.

I'm not in a position to test this for myself at the moment or would have done before posting.

I do use Vegas to render the timeline and use the template for 16:9 DVD (PAL) keeping it progressive all the way.

Any render ideas welcome.

[Randall Leong]

Unfortunately, Chris, SD DVD does not support 50p at all - at any resolution (you can only do 25p for "progressive" PAL DVD). The progressive PAL DVD preset does only 25p - and unfortunately, by default the Vegas encoder simply discarded half the frames during the process. So, the only way to maintain smooth motion would be to do 50i (interlaced) if your original source material is shot at 50 fps.

[Chris Harding]

Hi Chris

All my weddings are onto DVD and I have used 50P at some stages but mostly 50i
In project properties you need to make sure Vegas recognises the format and it should show up as 1920x1080 with an aspect ratio of 1 and the frame rate should be shown as "double frame rate"

It's already progressive so you can leave de-interlacing off but keep render to best.

When you render the footage out to SD use the DVD PAL Widescreen setting BUT make sure that it's set to "Lower Field First" and obviously 720x576 and render out to MPEG2

I doubt whether many domestic DVD players can accept a progressive file on them as the standard is 720x576 with the horizontal aspect changed to make the image fit the 1.777 aspect ratio and with the preset Vegas should automatically render your SD MPEG2 as an interlaced file.

Are you sure you are not attempting to watch the MPEG2 on your computer rather than from a DVD player?? If your software player on your computer is not set to handle the interlaced footage of the MPEG2 or DVD then things will look very weird!!

Chris

[Chris Hewitt]

Chris, I do match the properties settings in Vegas, set for 1920x1080/50P. All works fine on the timeline and looks good. I do use Mercali 2 a fair bit for handheld footage and it works fine on the timeline and preview.

The problems start when I watch the rendered (DVD) files on a LCD tv but this has only been happening recently. As you know, I use an AC160 and two CX730's (no problem with this camera when rendered) and shoot progressive 50P all the way. The Mercali'd files jump a bit where they don't on the timeline and not too smoothly either.

You say "When you render the footage out to SD use the DVD PAL Widescreen setting BUT make sure that it's set to "Lower Field First" and obviously 720x576 and render out to MPEG2."
I thought that DVD was capable of playing a rendered progressive file i.e. it's progressive on the disc, not interlaced. I've been rendering progressive to DVD and Media Info confirms that.

I haven't got access to my pc at the moment as I'm at a wedding today but will check when I get home tomorrow. Whatever it is, the render is where the problems occur.

Thanks both of you for your input, I really need to get to the bottom of this.

[Chris Harding]

Hi Chris

The first problem for me is that I have Vegas 10E and the preset "DVD PAL" seems to automatically set the interlacing to lower field first and it interlaces the MPEG2 ready to burn to DVD.

Whether I use progressive or interlaced footage on my timeline (usually mixed and always de-interlaced anyway) I have always just rendered out to Main Concept MPEG2 and used the DVD PAL preset.

I was under the impression that most domestic DVD players needed interlaced files for the player to be able to read the VOB files despite the fact that all LCD TV's are progressive scan. Maybe that's a misconception and DVD domestic players CAN read VOB files that are rendered as progressive..it certainly seems silly with virtually no-one using CRT TV's now that the player has to have the older interlaced footage and then has to send it to the TV with the interlacing stripped ??

Have you rendered MPEG2 files as progressive and played them on the TV? Does the player seem happy with them ???

Can any experts here confirm that all DVD players connected to an LCD TV, are happy with progressive files and there is no need to provide them with interlaced files any more ??

That would be a start anyway

Chris

[Chris Harding]

Hi Chris

A progressive MPEG2 file seems to work fine in Vegas 10 (I just changed the fields to 'none' in Custom) BUT I am a little worried about what Randall is talking about because the image is definitely looking soft and during the render my preview monitor shows the 50P timeline being rendered as 25 so I think that half the frames are indeed being discarded resulting in a softer image!

So what is the answer?? Render from your 50P timeline and re-introduce the interlacing ?? Maybe Randall can also help here on the rendering side. My DVD widescreen defaults to Lower Field First but I changed it to 'none" but the image does look a lot softer than a MPEG2 rendered with interlacing on!!

Chris

[Chris Hewitt]

Hi Chris, just got in from the wedding shoot so still haven't had time to check. ...but, yes, you can make a progressive DVD like Randall says but he has a point when he says that half the frames are discarded.
I shoot 50P just to get smooth motion but might have to go back to 25P.
I'll do some tests in the morning and post back when I get a good result. TBC

[Chris Harding]

Hi Chris

Sadly 25P isn't a format I'm too keen on as sudden movement even at something as placid as a wedding is going to produce blur or have you found otherwise??
I'm still shooting weddings in 50i and then, of course, de-interlacing in Project properties but I have kept the DVD PAL template as it is and I render out to MPEG2 with interlacing on lower field first and the SD DVD's look pretty good.

Since SD cannot support 50P which option is likely to give better results??

(a) Shoot in 50P and then render to MPEG2 interlaced
(b) Shoot in 50i and render to MPEG2 interlaced
(c) Shoot in 50i and render to MPEG2 progressive

Chris

[Gerald Webb]

50p on 25p timeline and marquee select all media and select Disable Resample.
Works a treat. And you have the ability to slo mo if needed.
Render out 1080p master and downsize with your preferred method to 25p DVD compatible file.

[Chris Harding]

Thanks Gerald

May I ask why you need to render twice?? Any special reason? Surely you can simply render out to a 25P MPEG2 DVD compliant file. So you set project properties to 1920x1080 25P and then dump the 50P footage onto the timeline?

I sure the other Chris will appreciate this information as it was his query in the first place.

Chris

[Gerald Webb]

Yes Chris,
25p 1920x1080 Project, drop in the 50p files. Must Disable resample though to avoid the frame blending that Vegas does.

Sure you could render straight to your delivery format from the timeline, 704x576 (if authoring in DVD Architect, if using Adobe Encore the files must be 720x576. Encore will not accept 704. Just a heads up :)

I just always render a Cineform archive version at full resolution, add a bit of sharpening in the metadata and then use that for downscaling. To each their own I guess.
FWIW If you really wanted to keep the smooth motion of 50p, why not deliver 720p 50 Bluray discs?

[Chris Hewitt]

Going to start my tests in a few minutes....how exactly do the Project Properties settings affect the final render? I thought that those settings just make the timeline playback easier if they match the source media.
Goes to show you never stop learning with Vegas!

[Chris Harding]

Great Gerald

Thanks! We would render out to DVD PAL MPEG2 file anyway so it would always be 720x576 .. I do my authoring with DVD lab ... I tried a 50P file on a 50P timeline and gosh the image really goes soft as anything but the DVD works perfectly.

I'll also give the very same test files I used and do it your way so I can compare the difference.

Chris? Let us also know your comments and results

Chris

[Chris Hewitt]

Right, this is what I found after a lot of small renders to mpeg2 DVD files playing off a thumbdrive, not a DVD on a 40" LCD tv.
I rendered with and without 'Disable Resample' and it didn't help. I rendered with Project Properties set to 1920x1080/25P and then to 50P. I introduced 'Reduce Interlace Flicker' later and that made little difference.
All possible combinations of one and the other, two pass and one pass at VBR.
And the winner is....

The Main Concept widescreen default template!!!

I shall be downsizing for the BluRay render to 1280/50P so I can keep at that framerate as DVD Arch doesn't support 1920/50P.

I came across your corrospondence here from Aug 2011, Chris , with Jerry Amende which seems to confirm what I found. http://www.dvinfo.net/forum/what-hap...ies-avi-2.html

From now on, I will revert back to shooting 1280/50P....1080/50P is too much hassle.

[Peter Riding]

For what its worth - and I haven't done any comparisons for ages so I can't remember why these properties were chosen - I use these default project properties:

http://www.ashtonlamont.co.uk/images/vegas-dvdpp.jpg

You'll see its 50p.

My 4 panny cams are all on 1920x1080 50p. My 5D cams are set to 1920x1080 25p and likewise my Gopro to 1920x1080 25p

I don't use the 5D's much for wedding work but I do use all the Pannys and the GoPro extensively.

My tweaked render settings for PAL DVD:

http://www.ashtonlamont.co.uk/images/vegas-dvd-rs.jpg

I use a constant 8 bps as its close to the maximum usable according to the DVD spec. but not so close as to be dangerous. Constant saves me having to do 2-pass - which is necessary on Variable as otherwise some of the stills I include can be noticeably degraded.I burn to dual layer discs if necessary.

I am more than happy with the results. No discs have ever been queried or returned by clients.

Pete