Field Order - HDV to MPEG2 for DVD output

[Jim Snow]

I am using Neo Scene in Vegas Pro 8. When I capture HDV from my camera, the field order is top field first which is normal for HDV. When I render to MPEG2 for output to a DVD, should I leave the field order as top field first? DVD's are usually bottom field first but if a video file is created top field first, will DVD players handle top field first videos without a problem?

[David Newman]

SD DVD is output is bottom field first, so you will need to set this.

[Jim Snow]

Thanks David. The problem that I am trying to solve is a play that I shot in HDV on a Sony FX-1. The background on the stage is a painting of a blue sky with a few clouds in it. I am getting a significant amount of flickering of the blue sky. That's why I am wondering if this was possibly a field order problem. I output it bottom field first. I haven't tried top field first yet.

[David Newman]

The type of flickering with indicate the issue. field order issues typically show as a temporal judder, motion seem to forward two steps and back one, then forward two. Flicker can also be due to aliasing of high frequency spatial information, on low frequency interlaced display. Both of these look normal for a static image on a progressive display. Get to know your flicker. :)

[Jim Snow]

There is no judder so I suspect that it is aliasing of high frequency spatial information. Are there any tricks to get rid of this? It happens only on the blue sky painting and nowhere else in the video.

[Robert Young]

Originally Posted by David Newman

SD DVD is output is bottom field first, so you will need to set this.

A common misconception. This subject came up in a big way a while back on the Procoder 3 forum because Procoder 3 defaults to UFF for DVD conversion. Some users thought it was an error, but in fact turned out not to be.
If your source footage is UFF, I recomend that you keep the field order UUF all the way thru the workflow. DVD players will play UFF without blinking an eye.
Switching field order as you move from source to delivery format can certainly be done with good results, but it is an unnecessary invitation for artifact.
After years of confusion and endless trial & error, the best looking interlaced DVDs I have ever made use this workflow:
Source footage 60i UFF> HDLink convert to CFHD.AVI 60i UFF> EDIT as CF> render edited timeline to CFHD.AVI 60i UFF Master Movie> HDLink convert to SD Master Movie CFSD.AVI 60i UFF> Transcode to DVD.m2v 60i UFF. The finished DVD, played on HDMI upscaling DVD player & viewed on HDTV, shows no motion artifacts, line twitter, jaggies, etc. and looks almost HD.
Try it- You'll like it!

[Ben Longden]

Most TV networks here require vision to be upper field first..

Ben

[John Rich]

Bob,

I've been capturing from my SONY HDR - XR520V, from the chip using HDLink and simultaneously deinterlacing, resulting in a 1920x1080 29.97 P clip. Then I edit with PP CS3 and a 1920x1080 P project and use Export - Movie to create the CF Master. Then I've just been outputting with Adobe Media Encoder to SD Progressive as MPEG2 for wide-screen DVD or H.264 at 1280x720P for Vimeo.

Since the original footage was 1920x1080 60i, would you favor just goiing through the whole process as interlaced to get to an interlaced output since the original footage was interlaced if I was just going to a DVD?

If I was going to use the progressive work flow I mentioned above, would it be better to down size the "Master" to SD using HDLink first and then encode with the AME or some other Mpeg2 encoder?

Thanks in advance,
John Rich

[Jim Snow]

Any ideas on the cause / fix for the flickering problem that I mentioned above?

[Robert Young]

Originally Posted by John Rich

Since the original footage was 1920x1080 60i, would you favor just goiing through the whole process as interlaced to get to an interlaced output since the original footage was interlaced if I was just going to a DVD?

If I was going to use the progressive work flow I mentioned above, would it be better to down size the "Master" to SD using HDLink first and then encode with the AME or some other Mpeg2 encoder?

Thanks in advance,
John Rich

John
If my final delivery format is to be interlaced (1920 Blu Ray, 60i DVD), I usually stay interlaced throughout, but you can do a progressive workflow and convert to interlace at the final transcode. It just divides the progressive frame into 2 interlaced fields- looks the same as 30p when played.

A square pixel progressive workflow seems to be much simpler and to have less potential for quirks than an interlaced workflow. The whole issue of rescaling to DVD (or any other progressive format) is more straightforward.
I convert the source footage to 1920x1080 CFHD 30p as you describe. From this square pixel, progressive format I have been able to get excellent DVD quality by converting to m2v directly from the timeline with AME- no need to render out to CFHD or CFSD master movie .avi.
If I am using 3rd party transcoder, like Procoder 3, then I need to render out a 1920 30p master avi for Procoder to use as a source.
You are also home free for progressive web transcodes (Flash, QT, etc.). You can transcode those directly from the timeline with AME as well.
This sort of progressive workflow seems pretty bulletproof- the one caution is that 30p renders motion less well than 60i. So you need to remember to use progressive shooting technique (even tho you are actually shooting 60i). Most common example is panning too fast: looks fine on your 60i source footage, but juddery & soft when converted to 30p.
Bottom line for me: If I am shooting for DVD or BR and I want the best motion capture (i.e. sports event) and the sharpest image, I shoot 60i and stay 60i throughout. If motion is not a big issue you can shoot 30p and stay progressive throughout and get excellent result as well.
No single "right" answer for how to do it.

[Robert Young]

Originally Posted by Jim Snow

Any ideas on the cause / fix for the flickering problem that I mentioned above?

I can't add much to what David has already said.
Is the flicker present on your original footage? If so, perhaps its a combo of the stage lighting characteristics + camera settings (like the flicker you can get shooting a TV or computer monitor).
If it is not present on the original footage, then it must be related to your workflow. Try staying UFF throughout. Try HDLink convert of original HDV to 1920 30p CFHD.avi & see if that eliminates it- that would also imply some sort of interlace issue.
Good luck

[Jim Snow]

Originally Posted by Robert Young

I can't add much to what David has already said.
Is the flicker present on your original footage? If so, perhaps its a combo of the stage lighting characteristics + camera settings (like the flicker you can get shooting a TV or computer monitor).
If it is not present on the original footage, then it must be related to your workflow. Try staying UFF throughout. Try HDLink convert of original HDV to 1920 30p CFHD.avi & see if that eliminates it- that would also imply some sort of interlace issue.
Good luck

Thanks Robert. If I render it as progressive, the flicker goes away. Of course I get the typical blurry edges on pans when interlaced footage is rendered as progressive so I can't use it. Strangely, the flicker only occurs on the blue sky painted background. This makes me wonder if the problem is the aliasing of high frequency spatial information that David Newman mentioned. If that's it, what can I do to fix it?

Added note: If I view the footage as HDV, I don't see it. When I view it after converting to Cineform, I see the flicker. If I put the HDV footage on the timeline, I don't see the flicker. Apparantly something is happening when I convert to Cineform.

[Robert Young]

Originally Posted by Jim Snow

Apparantly something is happening when I convert to Cineform.

The fact that the flicker goes away on conversion to 30p certainly implies that the problem is some sort of interlace issue- maybe a varient of line twitter.
When you convert to CF, are you converting to square pixel 1920x1080 framesize, or are you keeping the CF in the pixel shifted 1.33 1440x1080 HDV format?
I have had a variety of subtle & not so subtle issues associated with 1440 (including "line twitter" sort of artifacts) that seem to disappear with the 1920 sq pix workflow.
Maybe try it each way & see what happens.

[Jim Snow]

Originally Posted by Robert Young

The fact that the flicker goes away on conversion to 30p certainly implies that the problem is some sort of interlace issue- maybe a varient of line twitter.
When you convert to CF, are you converting to square pixel 1920x1080 framesize, or are you keeping the CF in the pixel shifted 1.33 1440x1080 HDV format?
I have had a variety of subtle & not so subtle issues associated with 1440 (including "line twitter" sort of artifacts) that seem to disappear with the 1920 sq pix workflow.
Maybe try it each way & see what happens.

Does NeoScene support converting to 1920x1080 from a HDV source? I don't see anything in Preferences that indicate this.

[Robert Young]

Hmmm... Maybe not. Look at the bottom of Prefs for "resize video", drop the menu down and scroll around.
I'm not familiar with NeoScene. I use Prospect HD.
In my experience, getting the footage into 1920x1080 right out of the camera impacts the entire workflow and certainly the final image quality for DVD & BR.
Lots of stubborn image quality problems simply disappeared when I moved to 1920. In fact all my cameras are 1920 now (XDCam & AVCHD). However, I did just finish editing a piece that was shot HDV 1440 60i, converted & edited as 1920 30p. Final BR & DVD look great using my same 1920 workflow as described above.
I think that the square pixel workflow is very important.
If you are going to be doing a lot of this sort of work, you might consider upgrading your CF software.