Interlace Hell at DVinfo.net

Ron Labbe · July 23rd, 2008, 10:09 AM

Hello~

I've searched the forum for an answer but no luck. I need help!

Imported HDV clips from Sony HDR-HD3, .m2t files. In WMP, these play jaggy (interlaced) on both my LCD and CRT. But in Premiere they look fine on both monitors.

Wanting to improve HDV workflow, purchased ASPECT HD 5.3.1, and transcoded one of the .m2t files in multiple .avi formats.

If I choose DEINTERLACE option (which I thought would make sense) the file plays like it was double-exposed (but not jaggy) in WMP and Premiere, on both monitors.

If I choose NO DEINTERLACE, In WMP the file plays JAGGY on LCD, but perfect on CRT. In Premiere the same file is "double" on either monitor. (!??)

Happens if I choose preset CINEFORM HDV 1080i or 1080p.

SO, my question is, how do I get a non-double CINEFORM file to play in Premiere?
THANKS for your help! (would screen shots help??)

David Newman · July 23rd, 2008, 10:48 AM

If you want to deinterlace, don't shoot with a shutter faster than 1/60th of a second -- that is causing the double image. If you deinterlace using only one field, the double image goes away, but then you only have an SD-like resolution. Interlace is a pain, avoid it in camera if you can. In Aspect HD the preview is showing the double image for the same shooting reasons, however it is only in the preview mode. You can control that in the preview setting, disabling preview playback and the fast scrubbing mode gets your the interlace image -- exports are always full quality, not impacted by the preview settings.

Ron Labbe · July 23rd, 2008, 12:15 PM

Thanks, the preview options are a good start...

We didn't change shutter speed settings as far as I know, I will have to check on that. When I've dealt with deinterlacing in the past, I've had a choice of doubling every other line or merging. Merging gives the double-exposure error, but I don't see an option for throwing out half the lines...?

David Newman · July 23rd, 2008, 12:26 PM

We don't offer a deinterlacer choice, as you can do the second style in Premiere. Merging (while we do more than that) only gives double exposure issues if the field rate and shutter speed don't match. Lock your camera to 1/60th.

Ron Labbe · July 23rd, 2008, 04:53 PM

David...

I appreciate your help on this, it's just a bit confusing. For example-

An interlaced Cineform AVI plays "double" in Premiere no matter how I configure playback when in CINEFORM editing mode. But if I bring the same file into Premiere in native 1080i editing mode, the file looks fine in the source monitor, but double in the program monitor.
(note: this file plays fine in WMP on a CRT, but jaggy on an LCD)

I'm quite sure we shot the original footage in default mode, which should have been 60fps.
So, I'm still baffled... thanks in advance!

David Newman · July 23rd, 2008, 04:59 PM

Display Preview Playback is the option your want for interlaced playback. In any case none of this impacts the export quality. It about how to deal with interlace data on a progressive display (your computer monitor.)

Ron Labbe · July 23rd, 2008, 05:09 PM

Perhaps I'm not in the right place... In the Cineform Display Control I see the option to check "Disable preview mode playback". Is that it? (Either way I get the same result.) If not, where?

I'm playing this on a CRT, which is an interlaced display, so I'm at a loss as to why it would be doubled in Premiere with the Cineform edit mode... (again, it plays perfectly fine in Windows Media Player).

David Newman · July 23rd, 2008, 05:43 PM

This is why interlaced should be outlawed. Likely your video card is weaving instead of bobbing. With "Disable preview mode playback" checked, we send the frame (fields not merged) to the video card.

Ron Labbe · July 24th, 2008, 07:29 AM

OK, interlace should be outlawed, but currently it's still legal. And we purchased ASPECT HD as it was purported to be the best solution for editing HDV on Premiere. But .m2t files look perfectly fine when scrubbed in the timeline, it's only the CINEFORM files that are doubled. So I don't see how it can be a problem with the video card? Are we going to be able to make Cineform work for us, or no?

thanks

July 23rd, 2008, 10:09 AM	#1
Ron Labbe Regular Crew Join Date: Jul 2008 Location: Maynard MA Posts: 40	Interlace Hell Hello~ I've searched the forum for an answer but no luck. I need help! Imported HDV clips from Sony HDR-HD3, .m2t files. In WMP, these play jaggy (interlaced) on both my LCD and CRT. But in Premiere they look fine on both monitors. Wanting to improve HDV workflow, purchased ASPECT HD 5.3.1, and transcoded one of the .m2t files in multiple .avi formats. If I choose DEINTERLACE option (which I thought would make sense) the file plays like it was double-exposed (but not jaggy) in WMP and Premiere, on both monitors. If I choose NO DEINTERLACE, In WMP the file plays JAGGY on LCD, but perfect on CRT. In Premiere the same file is "double" on either monitor. (!??) Happens if I choose preset CINEFORM HDV 1080i or 1080p. SO, my question is, how do I get a non-double CINEFORM file to play in Premiere? THANKS for your help! (would screen shots help??)

July 23rd, 2008, 10:48 AM	#2
David Newman CTO, CineForm Inc. Join Date: Jul 2003 Location: Cardiff-by-the-Sea, California Posts: 8,095	If you want to deinterlace, don't shoot with a shutter faster than 1/60th of a second -- that is causing the double image. If you deinterlace using only one field, the double image goes away, but then you only have an SD-like resolution. Interlace is a pain, avoid it in camera if you can. In Aspect HD the preview is showing the double image for the same shooting reasons, however it is only in the preview mode. You can control that in the preview setting, disabling preview playback and the fast scrubbing mode gets your the interlace image -- exports are always full quality, not impacted by the preview settings. __________________ David Newman -- web: www.gopro.com blog: cineform.blogspot.com -- twitter: twitter.com/David_Newman

July 23rd, 2008, 12:26 PM	#4
David Newman CTO, CineForm Inc. Join Date: Jul 2003 Location: Cardiff-by-the-Sea, California Posts: 8,095	We don't offer a deinterlacer choice, as you can do the second style in Premiere. Merging (while we do more than that) only gives double exposure issues if the field rate and shutter speed don't match. Lock your camera to 1/60th. __________________ David Newman -- web: www.gopro.com blog: cineform.blogspot.com -- twitter: twitter.com/David_Newman

July 23rd, 2008, 04:59 PM	#6
David Newman CTO, CineForm Inc. Join Date: Jul 2003 Location: Cardiff-by-the-Sea, California Posts: 8,095	Display Preview Playback is the option your want for interlaced playback. In any case none of this impacts the export quality. It about how to deal with interlace data on a progressive display (your computer monitor.) __________________ David Newman -- web: www.gopro.com blog: cineform.blogspot.com -- twitter: twitter.com/David_Newman

July 23rd, 2008, 05:43 PM	#8
David Newman CTO, CineForm Inc. Join Date: Jul 2003 Location: Cardiff-by-the-Sea, California Posts: 8,095	This is why interlaced should be outlawed. Likely your video card is weaving instead of bobbing. With "Disable preview mode playback" checked, we send the frame (fields not merged) to the video card. __________________ David Newman -- web: www.gopro.com blog: cineform.blogspot.com -- twitter: twitter.com/David_Newman

July 23rd, 2008, 12:15 PM	#3
Ron Labbe Regular Crew Join Date: Jul 2008 Location: Maynard MA Posts: 40	Thanks, the preview options are a good start... We didn't change shutter speed settings as far as I know, I will have to check on that. When I've dealt with deinterlacing in the past, I've had a choice of doubling every other line or merging. Merging gives the double-exposure error, but I don't see an option for throwing out half the lines...?

July 23rd, 2008, 04:53 PM	#5
Ron Labbe Regular Crew Join Date: Jul 2008 Location: Maynard MA Posts: 40	David... I appreciate your help on this, it's just a bit confusing. For example- An interlaced Cineform AVI plays "double" in Premiere no matter how I configure playback when in CINEFORM editing mode. But if I bring the same file into Premiere in native 1080i editing mode, the file looks fine in the source monitor, but double in the program monitor. (note: this file plays fine in WMP on a CRT, but jaggy on an LCD) I'm quite sure we shot the original footage in default mode, which should have been 60fps. So, I'm still baffled... thanks in advance!

July 23rd, 2008, 05:09 PM	#7
Ron Labbe Regular Crew Join Date: Jul 2008 Location: Maynard MA Posts: 40	Perhaps I'm not in the right place... In the Cineform Display Control I see the option to check "Disable preview mode playback". Is that it? (Either way I get the same result.) If not, where? I'm playing this on a CRT, which is an interlaced display, so I'm at a loss as to why it would be doubled in Premiere with the Cineform edit mode... (again, it plays perfectly fine in Windows Media Player).

July 24th, 2008, 07:29 AM	#9
Ron Labbe Regular Crew Join Date: Jul 2008 Location: Maynard MA Posts: 40	OK, interlace should be outlawed, but currently it's still legal. And we purchased ASPECT HD as it was purported to be the best solution for editing HDV on Premiere. But .m2t files look perfectly fine when scrubbed in the timeline, it's only the CINEFORM files that are doubled. So I don't see how it can be a problem with the video card? Are we going to be able to make Cineform work for us, or no? thanks