Completely interlaced workflow - why do I get interlacing artifacts?

[4100xpb]

I shot an event on two cameras, both set to 60i. One was HD, one SD (4:3). Clips from both were placed on the timeline of an NTSC widescreen project.

The SD clips were cropped to widescreen. HD clips were also cropped slightly. Minor colour correction applied, nothing else of significance was done to the clips. Project was rendered to the DVDA template for NTSC widescreen.

Playing the resulting MPEG-2 file on my computer or playing the DVD from that file on my television shows massive interlacing in the HD clips and somewhat noticeable interlacing on the SD clips to the point where the clips are not watchable.

Setting the project's deinterlacing to blend removes the artifacts and produces some blurring in the affected areas, but is perfectly watchable.. Viewing the source files shows no artifacts on the camera or on the computer.

Does cropping the clips induce the potential for problems like this, or is there something else going on?

 

[David Jimerson]

You'll certainly see interlace artifacts from an NTSC DVD MPEG-2 file on a computer. You probably will on a progressive TV (such as an HDTV), too, depending on player and TV settings.

If you want the 60 fps cadence, I wouldn't deinterlace it; you're effectively creating 30p.

 

[PDR]

You can activate a deinterlacer for MPEG2 files upon playback with software . e.g. in vlc video=>deinterlace on . You can choose mode "yadif 2x" if you want 60p , "yadif" if you want single rate 30p . Some players will automatically deinterlace e.g. kmplayer , and you can configure certain decoders to deinterlace as well

playing the DVD from that file on my television shows massive interlacing in the HD clips and somewhat noticeable interlacing on the SD clips to the point where the clips are not watchable.

If this was an authored DVD, this should not happen

How did you do the crop? or resize HD? Did you do it in vegas ? What settings & steps did you take in making the DVD ?

 

[4100xpb]

Thanks Guys

David

While I expect some interlacing on an MPEG-2, this is way out of line from anything I've seen before. I'll try and post a clip later. It was played on an HDTV/blu-ray player so it may not have dealt with the interlacing properly either. I'll see if I can try it on a standard DVD player/CRT television. Good point about the cadence, I can live with 60i or 30p, so deinterlacing is okay for a workaround.

PDR
I'm just using windows media player. Not sure how to force the deinterlacing with that it's always worked fine automatically before, but it's never given me a problem like this before. My steps in making the DVD:
1. Import clips into project media (NTSC DV 4:3 and NTSC HDV, both in 60i).
2. Mixed clips on the timeline.
3. Project properties set to NTSC DV Widescreen, left at the defaults
4. Crop on the SD clips to crop them to widescreen
5. Crop on the HD clips to fit the frame
6. Minor colour correction on the SD clips.

From there I rendered the video
Render as MainConcept MPEG-2, DVD Architect NTSC Widescreen Video Stream. Quality set to high, everything else left to the defaults. Rendered .ac3 audio separately.

In DVD Architect - New project, single movie. Selected the video file, it brought it and the audio in fine. Prepped and burned to DVD.

I tried running it in VLC player, and no matter what I set the de-interlacing to, the problem remained.

The sample file here is a clip that shows the interlacing pretty clearly (password - interlace). As mentioned before, it shows up regardless of de-interlacing settings, and on my dvd player and tv. Like I said, using blend de-interlacing in Vegas manages the issue fine for my purposes, I'm just trying to figure out what is going on. Thanks again for your help.

 

[PDR]

What version of vegas?

If that's what you see on a DVD, those thick bands artifacts indicate resize before deinterlacing (i.e. improperly done interlaced resize). But it's hard to say because you didn't say what you did to the vimeo footage. You usually deinterlace for web, or did you upload interlaced footage? That vimeo video is 640x360 so resizing was done somewhere

Both interlaced resizing and interlaced cropping requires special treatment, newer versions of vegas handle it ok, but IIRC old versions screwed it up.

Can you upload a clip not processed or resized by vimeo (e.g. use a free hosting site like mediafire.com)

I'm a bit confused by your terminology

1. Import clips into project media (NTSC DV 4:3 and NTSC HDV, both in 60i).
2. Mixed clips on the timeline.
3. Project properties set to NTSC DV Widescreen, left at the defaults
4. Crop on the SD clips to crop them to widescreen
5. Crop on the HD clips to fit the frame
6. Minor colour correction on the SD clips.

By "crop" do you mean resize ? Or do you really mean you are cropping HD footage down to SD?

And what do you mean "crop them to widescreen" for the SD clips ?