"choppy" movement when transferred to DVD at DVinfo.net

Nicholas Bone · March 6th, 2006, 08:56 AM

I've shot some dance material on a PD170. When transferred out of Avid Xpress into a QuickTime reference movie and then into Procoder for transfer to DVD the movement gets a "jaggy" look, with lines coming out of edges giving the movement a strange look.
I think this is an interlacing problem. De-interlacing helps a bit, but my question is this - can it be avoided in the first place, rather than trying to correct it afterwards? Are there settings I should be looking at when importing the material or even beforte shooting it?
Is progressive scan any help when recording fast movement? (Though I read on another thread that Sony prog scan is not "real").
Any thoughts and advice for both solving the problem in the most effective way and of avoiding it in the future would be greatly appreciated.

Emre Safak · March 6th, 2006, 09:19 AM

Does it look bad when viewed on a TV rather than through a computer?

Nicholas Bone · March 6th, 2006, 09:56 AM

Yes, it looks bad on both TV and computer.

Christopher Lefchik · March 6th, 2006, 11:19 AM

It sounds like somewhere along the line the two fields that make up a frame are being combined. That is what would give you the "lines coming out of edges", or combing effect. I don't have any experience with Avid or QuickTime reference movies, so I'm afraid I can't give you any advice on exact settings.

Mike Oveson · March 6th, 2006, 04:45 PM

Quote:

Originally Posted by Nicholas Bone

De-interlacing helps a bit, but my question is this - can it be avoided in the first place, rather than trying to correct it afterwards? Are there settings I should be looking at when importing the material or even beforte shooting it?

Is progressive scan any help when recording fast movement? (Though I read on another thread that Sony prog scan is not "real").
Any thoughts and advice for both solving the problem in the most effective way and of avoiding it in the future would be greatly appreciated.

Yeah, it sounds like an interlacing problem. I would deinterlace your footage, that should take care of it. Well, as much as it can be taken care of. But really, if you do a deinterlace it shouldn't be a big issue. I don't think there are any settings you can do to change this. 60i is interlaced, and that is what your camera shoots in. If you do have a "progressive" setting on your camera then it's simply a frame-blending mode that is a pseudo-progressive mode, not true progressive. True progressive frames will not have any interlacing issues, due to the nature of the imaging system.

I'm not a user of Avid Express either so I'm not sure what else to tell you. If you know how to deinterlace the footage (and it sounds like you do) I'd do that. If you can post a before/after picture that would also be helpful. It really shouldn't be noticeable after you deinterlace, and I would assume Avid Express can handle deinterlacing.

Robert M Wright · March 6th, 2006, 09:31 PM

Is your television a CRT, or is it an LCD, Plasma, etc?

Have you checked to see if your DVD player is set to output interlaced or progressive scan video?

Nicholas Bone · March 7th, 2006, 03:06 AM

The TV is CRT - I'll check about DVD player settings. Thanks for all the advice so far - I'll report back. Also found this site about de-interlacing which is worth a look: http://www.100fps.com

Paul Jefferies · March 7th, 2006, 07:54 AM

hi,
I always do de-interlacing as the very last thing in editing, right before going to dvd. If you do it earlier on and then apply an effect it can create all kinds of problems

David Lach · March 7th, 2006, 09:24 AM

If you shot your footage in 60i and then exported it to DVD as progressive footage without de-interlacing first this can be the source of a problem. Make sure to output the footage with the same settings it was shot in. That will at least get rid of one problem if viewed on a standard TV. Make sure to remain with a "lower field first" setting throughout your various capture and transfer stages.

If viewed on a progressive scan monitor such as a computer monitor, then you will see the lines if it's not de-interlaced. The only way around is to shoot progressive scan. But by doing so you might trade the combing effect for some jerky looking video if shooting fast paced action with lots of movement.

Christopher Lefchik · March 7th, 2006, 09:45 AM

Unless one has a good deinterlacer I would not recommend deinterlacing footage shot in 60i, as you would lose 50% of your resolution. Personally, I've always shot 60i and I've never had a problem with interlacing when playing my DVDs on a television.

Playing interlaced footage on computer monitors is another thing, however, and probably always will be due to the fact that computers monitors are progressive scan. In this case the quality of the playback depends on the software player and the settings therein.

The fact is, while I can understand the combing effect when playing the 60i DVD on the computer, he should not be getting it on the CRT TV. That is an abnormality and should not be happening. A setting is wrong somewhere in Avid or his DVD authoring software. Deinterlacing should not be required to fix this problem.

Ricki Lau · March 7th, 2006, 07:37 PM

I had the same problem when I change clips from Pal to NTSC. I'm currently using a Pal sony pd-150 cam and living in canada, toronto.

Nicholas Bone · March 8th, 2006, 07:11 AM

Okay - I'm not sure exactly how, but I seem to have solved the problem. I went back to Avid and re-exported, then re-coded and it now runs smoothly when viewed on a TV. I checked all the settings carefully (particularly "lower field first" ones) so I guess that I must have had a setting wrong somewhere, though nothing obvious appeared as I was checking. I'm new to Procoder, having used TMPGEnc before, so I suspect that I did something wrong there. Anyway,thanks for all help and advice.

March 6th, 2006, 08:56 AM	#1
Nicholas Bone New Boot Join Date: Nov 2005 Location: Edinburgh, UK Posts: 5	"choppy" movement when transferred to DVD I've shot some dance material on a PD170. When transferred out of Avid Xpress into a QuickTime reference movie and then into Procoder for transfer to DVD the movement gets a "jaggy" look, with lines coming out of edges giving the movement a strange look. I think this is an interlacing problem. De-interlacing helps a bit, but my question is this - can it be avoided in the first place, rather than trying to correct it afterwards? Are there settings I should be looking at when importing the material or even beforte shooting it? Is progressive scan any help when recording fast movement? (Though I read on another thread that Sony prog scan is not "real"). Any thoughts and advice for both solving the problem in the most effective way and of avoiding it in the future would be greatly appreciated.

March 7th, 2006, 09:45 AM	#10
Christopher Lefchik Trustee Join Date: Jul 2003 Location: US Posts: 1,152	Unless one has a good deinterlacer I would not recommend deinterlacing footage shot in 60i, as you would lose 50% of your resolution. Personally, I've always shot 60i and I've never had a problem with interlacing when playing my DVDs on a television. Playing interlaced footage on computer monitors is another thing, however, and probably always will be due to the fact that computers monitors are progressive scan. In this case the quality of the playback depends on the software player and the settings therein. The fact is, while I can understand the combing effect when playing the 60i DVD on the computer, he should not be getting it on the CRT TV. That is an abnormality and should not be happening. A setting is wrong somewhere in Avid or his DVD authoring software. Deinterlacing should not be required to fix this problem. Last edited by Christopher Lefchik; March 7th, 2006 at 11:10 AM.

March 6th, 2006, 09:19 AM	#2
Emre Safak Trustee Join Date: Feb 2004 Location: Brookline, MA Posts: 1,447	Does it look bad when viewed on a TV rather than through a computer?

March 6th, 2006, 09:56 AM	#3
Nicholas Bone New Boot Join Date: Nov 2005 Location: Edinburgh, UK Posts: 5	Yes, it looks bad on both TV and computer.

March 6th, 2006, 11:19 AM	#4
Christopher Lefchik Trustee Join Date: Jul 2003 Location: US Posts: 1,152	It sounds like somewhere along the line the two fields that make up a frame are being combined. That is what would give you the "lines coming out of edges", or combing effect. I don't have any experience with Avid or QuickTime reference movies, so I'm afraid I can't give you any advice on exact settings.

March 6th, 2006, 09:31 PM	#6
Robert M Wright Inner Circle Join Date: Jan 2006 Location: Minnesota (USA) Posts: 2,171	Is your television a CRT, or is it an LCD, Plasma, etc? Have you checked to see if your DVD player is set to output interlaced or progressive scan video?

March 7th, 2006, 03:06 AM	#7
Nicholas Bone New Boot Join Date: Nov 2005 Location: Edinburgh, UK Posts: 5	The TV is CRT - I'll check about DVD player settings. Thanks for all the advice so far - I'll report back. Also found this site about de-interlacing which is worth a look: http://www.100fps.com

March 7th, 2006, 07:54 AM	#8
Paul Jefferies Major Player Join Date: Nov 2005 Location: Croydon, England Posts: 277	hi, I always do de-interlacing as the very last thing in editing, right before going to dvd. If you do it earlier on and then apply an effect it can create all kinds of problems

March 7th, 2006, 09:24 AM	#9
David Lach Major Player Join Date: Oct 2002 Location: Montreal, QC, Canada Posts: 570	If you shot your footage in 60i and then exported it to DVD as progressive footage without de-interlacing first this can be the source of a problem. Make sure to output the footage with the same settings it was shot in. That will at least get rid of one problem if viewed on a standard TV. Make sure to remain with a "lower field first" setting throughout your various capture and transfer stages. If viewed on a progressive scan monitor such as a computer monitor, then you will see the lines if it's not de-interlaced. The only way around is to shoot progressive scan. But by doing so you might trade the combing effect for some jerky looking video if shooting fast paced action with lots of movement.

March 7th, 2006, 07:37 PM	#11
Ricki Lau New Boot Join Date: Feb 2006 Location: Toronto Posts: 6	I had the same problem when I change clips from Pal to NTSC. I'm currently using a Pal sony pd-150 cam and living in canada, toronto.

March 8th, 2006, 07:11 AM	#12
Nicholas Bone New Boot Join Date: Nov 2005 Location: Edinburgh, UK Posts: 5	Okay - I'm not sure exactly how, but I seem to have solved the problem. I went back to Avid and re-exported, then re-coded and it now runs smoothly when viewed on a TV. I checked all the settings carefully (particularly "lower field first" ones) so I guess that I must have had a setting wrong somewhere, though nothing obvious appeared as I was checking. I'm new to Procoder, having used TMPGEnc before, so I suspect that I did something wrong there. Anyway,thanks for all help and advice.