4:3 to 16:9 is beginning to undermine my sanity

scissorfighter wrote on 11/19/2004, 2:56 PM
Ok guys, what the heck am I doing wrong here? This issue appears to haunt many on this forum, but I can't find a clear resolution to the problem despite the fact that it's been discussed in one form or another several times.

The problem I'm having is appearing when I try to convert native 4:3 DV footage to 16:9 format. My desired destination is DVD, but that's irrelevant (I think) at this point. When doing the conversion, the resultant footage has terrible "interlace tearing" in scenes with horizontal motion. I've tried this multiple times using multiple sources, including both captured video and Vegas generated media. Here is the process I follow:

1) Capture footage as native 4:3 DV
2) Start a new vegas 5 project, and set the template to NTSC DV Widescreen (thus changing the pixel aspect ratio to 1.2121)
3) Import captured clip into media pool
4) Drag media to timeline
5) Select first frame of media and click the event pan/crop button on the clip itself
6) Right-click on image window and select "match output aspect"
7) Close event pan/crop window
8) Choose File... Render As...
9) Select MainConcept MPEG-2 as type (I've tried AVI DV as well and get the same problem)
10) Choose DVD Architect NTSC Widescreen Video Stream as the template
11) Save

This method appears to be the consensus I've found in this forum for conversion of 4:3 to 16:9. But the results (for me) are obviously incorrect. If any of you would like to see a before and after sample of this problem, I have posted two .mpg clips on my website for download (7 MB each) - the 4:3 version as original, and the converted 16:9 version with the problem. See below for links to download. To create these clips I simply used a Vegas-generated horizontal credit roll, and then saved it as a 4:3 DV file. Then I tried to convert it to 16:9 as I would any other 4:3 DV media. You should be able to try this at home! The problem is exactly the same regardless of whether or not I use generated or captured media. The tearing problem is visible all the time... when previewed on an external monitor, when viewed on a PC (though not as bad), when previewed in DVDA, and when burned to a DVD and played on a television.

The only thing I would mention is that some posts in this forum regarding 4:3 to 16:9 conversion also indicate that you should use 2-3 pulldown when rendering. I have ignored this recommendation, since I do not want to change FPS to 24, but instead want to remain at 29.97.

Am I missing something painfully obvious here, or is 4:3 to 16:9 really this hard?

To download sample mpg clips, click the links below. I also posted a screenshot from the DVDA preview window that's only a few K if you want to peek at that instead, but you have to "imagine" it scrolling from left to right!

http://www.ryanhaskell.com/credits.jpg
http://www.ryanhaskell.com/credit43.mpg
http://www.ryanhaskell.com/credit169.mpg

Thanks everyone for your help in advance!
Ryan

Comments

Spot|DSE wrote on 11/19/2004, 5:09 PM
Are you trying to render progressive? Or interlaced? What you've got there is obviously a field error. I've not looked at your mpegs, but can see that in the credit, obviously.
4:3 to 16:9 is really easy...In fact, Ultimate S does this for you.
scissorfighter wrote on 11/19/2004, 6:05 PM
Spot,
I'm trying to render interlaced. I'm assuming that's the way to go for output to DVD with the primary end viewing device a standard television. The source material is interlaced, and the destination 16:9 render is set to interlaced (I've tried both lower field first and upper field first.)

Ryan
Spot|DSE wrote on 11/19/2004, 6:51 PM
Should always be lower field first if you're dealing with NTSC.
My old workflow is this:
Shoot 4:3
Open 4:3 project, edit, create everything but generated media.
Convert to 16:9 by changing project aspect, and then running the Match Aspect script.
Create generated media.
Now, I just import /edit all my media and run Ultimate S though. Faster. Then I create generated media.
You should only be seeing the interlace artifacts on generated media, yes?
Laurence wrote on 11/19/2004, 9:28 PM
The one thing you might add to that is that you can also generate both 4:3 and 16:9 versions from the same 4:3 footage. Just make sure that you only convert footage and create generated media directily in the end format aspect ratio.

Once I get one of the new Sony HDV cameras though, I suppose I'll be shooting 16:9 and ignoring 4:3 altogether. Altough I'm sure I'll still use this technique to import 4:3 material into 16:9 projects.

Be aware that creating 16:9 this way does it by doubling lines - the same lines that are removed by your DVD player when you watch anamorphic footage on a 4:3 TV set. These are also the same lines that are doubled if you have a camera with the fake "stretch" 16:9 mode (PD150, VX2000, DVX100). The quality is the same generating "stretch mode" this way as it is using one of these cameras ( though progressive mode generates a slightly sharper picture this way because of a line averaging thing that interlaced cameras do). There is also no quality difference on a regular TV set between native 16:9 and 16:9 footage that was created from 4:3 or shot with a fake "stretch" mode 16:9 camera. It is only when you watch the video on a widescreen TV that you'll see the difference.

I'm getting ready to spend $4,900 on one of the new Sony HDV cameras knowing full well that by the time I go to DVD, only me and two other people that I know will have setups where the difference will even be visable! Try explaining that one to my wife! ;-)
scissorfighter wrote on 11/20/2004, 4:11 AM
No, the artifacts occur with both captured media right off the camera, as well as generated media. I only did the generated media test to see if it would behave the same as my 4:3 video footage, and it does, so I posted that as the example because it would be easy for others to replicate. My workflow is basically the same as yours, except I'm not using the Ultimate S script.

I downloaded the Ultimate S demo this morning, and had the same problem. Here are the exact steps I took:
1) Shot new 4:3 footage with my DV cam
2) Launched vegas and captured video
3) Dragged clip from media pool to timeline
4) Opened Ultimate S
5) Selected the film look tab
6) placed check in "Convert 4:3 project to widescreen" box, and pressed "OK"
7) File...Render As...
8) Rendered as MPEG2 with the DVDA NTSC Widescreen template at default settings (interlaced, bottom field first, 16:9, 29.97)

Resulting MPEG file has the exact same problem.
Any ideas?

Thanks for the input so far!
Ryan
farss wrote on 11/20/2004, 4:57 AM
Simple suggestion, right click event and turn on Reduce Interlace Flicker. For some reason that I cannot fathom when Vegas rescales frames you can get something between minot to really bad interlace artifacts and I have no logical explaination as to why but the Reduce Interlace Flicker switch seems to stop it.
If found this the solution to the problem when resize 8mm film source and during PAL to NSTC conversion, one day, just maybe one of the Sony gurus will give an explaination as to just what that switch does and maybe then I can fathom why it cures this problem.
Hope this cures your problem.
Bob.
PAW wrote on 11/20/2004, 8:26 AM

I have had this going from 4:3 PAL to 16:9 PAL

What I did was render the project out to progressive AVI then drop it into a new project and render out to MPEG

Fixed it for me

Paul
Spot|DSE wrote on 11/20/2004, 9:16 AM
Scissorfighter, you bring up a good point. Reduce Interlace flicker is globally applicable in Ultimate S, but it's not part of the 4:3 to 16:9 conversion, and maybe should be an option. It can soften the image, so it's not automatically applied, but users might find that as a useful option. We'll look into it.
Laurence wrote on 11/20/2004, 11:54 AM
I'll bet I know what is going on here! When you go from 4:3 to 16:9, the image will be cropped at the top and the bottom. You can move this window up and down, but you have to do it an even number of lines otherwise the fields get reversed. You won't even notice it on the computer monitor because it is showing both fields at once, but as soon as you see it on a regular interlaced TV it will look absolutely horrible! I'll bet you moved the window a little up or down and that amount happened to be an odd number of lines. Now your field order is reversed and it looks terrible on a TV. I did this exact thing when I first did the 4:3 to 16:9 conversion. I'll bet you anything that that is your problem!
scissorfighter wrote on 11/20/2004, 6:53 PM
And the winner is.... Farss! The reduce interlace flicker switch was the solution. Thanks! Valiant guess though, Laurence. So now the question is why? What is the technical issue that's occuring here, and why does the reduce flicker option mitigate it? There is definately a noticable degredation in quality as well, and I'm surprised that others have been doing 4:3 to 16:9 without complaining about the resulting quality.

Also, to test Laurence's theory, I did a test with the pan/crop settings. I made 10 different copies of the same clip, and adjusted the Y center position of the letterbox crop by + 0.1 for each clip. Then I made 10 more copies of the original, and adjusted the Y center by +1 for each clip. All rendered clips had the same interlace problem.

Thanks all,
Ryan
PAW wrote on 11/21/2004, 1:03 AM

Laurence,

Sounds like what I had seen. I have been moving the pan/crop window to suit the situation.

Going progessive as an intermediate step would have done the same as the computer monitor. I had tried reduce interlace flicker but it did not work in my scenario.

I have got details of what reduce interlace flicker does somewhere, i'll dig it out and post it.

Paul