interlace problem or compression...

Premiere 6.5

XP sp2

Quad-core 266

4 Gb RAM

7200 rpm SATA HDD for video projects

I am working on a volunteer project for a local museum wherein some old VHS tapes need to be digitized.?The final video (probably MPEG-2) will be accessible from research computers at the museum.?File size is not a big issue, but preserving as much quality (such as it is) from the 10+ year old VHS (not SVHS) tapes is essential.

So I feed the analog output from my tape deck to my Sony TVR310 camcorder for A/D conversion, then capture from there to my PC via firewire.?I have tried capturing via the software that came with my Edius (a.k.a. Canopus) card, and also directly into Premiere.?Same thing happens both times.

On the exported video (AVI, MPG1, MPG2) I see these wavy edges on the left and right sides of high-contrast areas.?See the guy's hat in the attached image (if it ever gets outa the queu).?Does this look like a compression artifact??Or is it an interlace problem??I do not see this effect when I watch the original video on my TV.

Note that Premiere reports the average data rate for the 720x480 @ 29.97 fps clip as 3600 kb/s.?So when I export to MPEG I set the data rate at 5000 kb/s.

When I process and export the video in Premiere, I have ''no fields'' selected everywhere, and for the actual export I have selected the ''de-interlace'' option.?Since this is for viewing on computers only, I figured that was the correct thing to do.

Edited:?I should also mention that I do not see this effect in the monitor window when I scrub the clip on the timeline.

Dan Heim

interlace problem or compression...

As you do not see this comb effect on your tv its a interlaced 'problem'.

This is quite normal as a computer display is progressive you will see these lines.

If your dvd is going to be shown on anything but a tv deinterlace the footage on output.

interlace problem or compression...

Thanks for your reply. Correct, I do not see this ''comb'' effect when the

original VHS tape is viewed on TV. I also do not see it on the captured

footage when scrubbed on the timeline in Premier.

The final output video will only be viewed on a computer monitor.

But here's where it gets weird ... I ran some tests, exporting that section

of the clip as an uncompressed AVI. Whether I had ''deinterlace'' turned on

or off, and for all export field orders (UFF, LFF, no fields) I still see

the effect. So I guess that means it's NOT a compression artifact.

As I said, all my project settings (including capture) are ''no fields.''

Maybe this is where I messed up?

Dan Heim

You also said OLD tapes... so it could be that the tapes are beginning to lose the magnetic pattern

Depending on just what goes in when you pass the signal through your camera, you may need a better digitizing device

Old forum message, message now gone, but here's the summary - I have not used, only made note of the product ''Matt with Grass Valley Canopus in their tech support department stated that the 110 will suffice for most hobbyist. If a person has a lot of tapes that were played often the tape stretches and the magnetic coding diminishes. If your goal is to encode tapes in good shape buy the 110, if you will be encoding old tapes of poor quality buy the 300''

http://desktop.thomsongrassvalley.com/products/ADVC300/index.php about $500
Or
http://www.amazon.com/Canopus-ADVC300-Advanced-Digital-Converter/dp/B0006UMGHE

John, the Sony TVR310 has always worked for me in the past.?And like I said, I don't see the artifacts when I play the tape to TV, nor do I see it in the monitor when I scrub the timeline.?It's gotta be some setting somewhere that I'm messing up.

Dan Heim

You say everyting is progressive. That cant be right.

If captured through the tvr130, footage is interlaced and so should your project settings.

If you want to deinterlace you set this in the output settings.

I just caught that. What I need to select for that option is the

characteristics of the OUTPUT device. Digital 8 camcorders are LFF, so

that's what I need to set it to. I'll retry that capture and let you know

what happens.

Question: since the VHS tape is UFF, when I use the camcorder as my A/D

converter, it must convert (deinterlace and reassemble) from UFF to LFF.

Correct?

Dan Heim

Yes when capturing through the camera it becomes lower field.

The first time I tried with the capture settings reset to LFF, and then tried to export (as uncompressed AVI), specifying ''no fields'' in the ''keyframe and rendering'' dialog box, and selecting ''deinterlace'' in the ''special processing'' dialog box, I still got those artifacts.

THEN ... after searching the help file for ''deinterlace'' and reading all the linked pages, I tried right-clicking on the clip on the timeline, went to ''video options'' / ''field options'' and selected ''always deinterlace.''?Had to re-render on the timeline.?Then, after exporting same as before, the artifacts were finally gone.

So you were correct about it being an interlacing issue.?Thanks for the insight!?GSpot now reports the exported video as 29.97 frames and 0 fields.

Here's a puzzle though ... I tried the same thing with the original clip (the one captured as progressive instead of LFF) and it smoothed out as well.?Perhaps Premiere is smart enough to recognize what it's getting for input, and ignores stupid commands??Whatever, this means I can use my original footage and not have to recapture 1.5 hours of video.

Dan Heim

The camera caputures interlaced and lower field, you cannot change that.

Its all in the project settings matching the footage and then setting it to the desired output.

Good luck on the project.

Ann et al.,

Thanks.?You can see I've marked this question as ''answered.''?The key was to capture LFF, then deinterlace on the timeline, then export as ''no fields'' with ''deinterlace'' selected again in the export processing.?I've also found that applying an antialiasing filter smooths things even further, but does add quite a bit more rendering time.

Dan Heim