Slo-mo problem in Vegas at DVinfo.net

Patrick Janka · July 2nd, 2010, 05:13 PM

I don't know what I did wrong. I filmed the majority of this video in 60i with a 1/1000 shutter. In Vegas I slowed down the footage and rendered to 30p. I have tried rendering it to an interlaced file, I have tried different formats, etc. and nothing seems to work. What's weird is when I watch it in the preview window it plays just as it should. The last part of the video was me testing combining 60i footage with 30p footage in the same file. Is there a reason why it's stuttering like this??

YouTube - Testing a Messed Up Render

Prech Marton · July 4th, 2010, 06:08 AM

looks like wrong field order (upper vs lower)

Bruce Phung · July 4th, 2010, 08:37 AM

Your video is 60i interlaced and you render your video in 30P. I think that is caused your problem. You should only render in 30P if your camera shoot 30P. Try to render 29,97 template. or wrong field order?

Brian Karr · July 4th, 2010, 09:28 AM

Try right clicking your clip on the time line, select properties, and then disable re-sampling.

Patrick Janka · July 6th, 2010, 02:21 AM

Brian, your solution got me halfway there. I also had to switch from Blend to Interpolate in De-interlacing method. Is disabling re-sampling something that has to be done every time I use interlaced footage? Also, what is the best way to combine clips of different frame rates? When adjusting the project settings it assumes you're only using one frame rate. In this case I used 60i, but the 30p stuff at the end didn't seem to get affected adversely. Is that because 30 is a multiple of 60? If I placed a 24fps clip in there would it have issues?

John Wiley · July 6th, 2010, 03:50 AM

My experience with Vegas is that it is terrible at handling interlaced footage but quite good at de-interlacing.

I shoot everything at 50i currently, but always edit on a 25p Vegas timeline with the properties set to "field order: none" and "deinterlace method: Interpolate."

It seems to do a good job of deinterlacing all my footage and getting rid of interlacing artifacts, but when I slow rootage down then all the "B" field gets thrown back into the mix to give you better resampling results. I've always left my clip poperties to "smart resampling" and unless I'm going to super slow motion (like 15% or something like that) it usally gives very acceptable results.

Bill Binder · July 6th, 2010, 03:49 PM

Project set to 29.97 progressive with none for deinterlace.
Make sure snap to frames is enabled
Drop 60i clip into timeline
Set clip properties to .5 speed and check do not resample
Stretch clip out so the whole clip is viewable (now that it's playing at half speed)
Render out to 29.97 progressive

Not sure that will work, but I think so. Also, this is one case where you kind of DON'T want to deinterlace first because you want to take each interlaced half frame that runs at 60i and map each to one frame running at 30p. Depending on where you delace, you could end up unnecessarily losing temporal or spatial resolution. Not sure that makes sense...

Brian Karr · July 6th, 2010, 07:28 PM

So it sounds like there are three issues at play here:

1. Re-sampling the images when you are using the velocity curve to create slow motion.
2. Interlaced images are being converted to progressive.
3. Different frames rates are being used.

1. Anytime I use the velocity curve to slow down footage I disable re-sampling. John mentioned he does this around 15%, my preference is to always do it as I believe the image stays sharper, but its personal preference.

2. I agree with John that Ive found Vegas is pretty good at de-interlacing. In the project properties however, Ive usually set the de-interlace method to blend fields. Need to play with this as I have not used much interlaced footage lately. If de-interlace works than thats the setting to use! Im fairly sure its a lot easier to convert a progressive image to interlaced (basically split the fields), than it is to create progressive from interlaced. In the latter case, there is interpolation and/or other math going on to combine the fields to a progressive image.

3. How I work is I set the project properties to the frame rate I intend to deliver in. Vegas does a good job of dealing with different frame rates for you. If you use 24p, then pulldown will be implemented. As an example, I setup a lot of 1280x720p29.97 projects. I will use 1280x720p59.94 footage in it quite a bit and either slow it by half to 29.97 or even slower. I tend not to mix 24 fps footage with projects that are not 24p, although most of my interests are in fast moving subjects. i.e. Im usually looking to shoot as high a frame rate as possible, and always shoot progressive.

July 2nd, 2010, 05:13 PM	#1
Patrick Janka Major Player Join Date: Jan 2010 Location: Orlando, FL Posts: 623	Slo-mo problem in Vegas I don't know what I did wrong. I filmed the majority of this video in 60i with a 1/1000 shutter. In Vegas I slowed down the footage and rendered to 30p. I have tried rendering it to an interlaced file, I have tried different formats, etc. and nothing seems to work. What's weird is when I watch it in the preview window it plays just as it should. The last part of the video was me testing combining 60i footage with 30p footage in the same file. Is there a reason why it's stuttering like this?? YouTube - Testing a Messed Up Render

July 4th, 2010, 06:08 AM	#2
Prech Marton Major Player Join Date: May 2004 Location: hungary Posts: 462	looks like wrong field order (upper vs lower) __________________ Relaxing clips with waterfalls and music, 3D photos, 3D videos: www.3d-video.hu

July 4th, 2010, 09:28 AM	#4
Brian Karr Regular Crew Join Date: Jan 2006 Location: Rockledge, Florida Posts: 36	Try right clicking your clip on the time line, select properties, and then disable re-sampling. __________________ Brian K www.vimeo.com/briankarr

July 6th, 2010, 03:49 PM	#7
Bill Binder Major Player Join Date: Jun 2005 Location: San Francisco Posts: 542	Project set to 29.97 progressive with none for deinterlace. Make sure snap to frames is enabled Drop 60i clip into timeline Set clip properties to .5 speed and check do not resample Stretch clip out so the whole clip is viewable (now that it's playing at half speed) Render out to 29.97 progressive Not sure that will work, but I think so. Also, this is one case where you kind of DON'T want to deinterlace first because you want to take each interlaced half frame that runs at 60i and map each to one frame running at 30p. Depending on where you delace, you could end up unnecessarily losing temporal or spatial resolution. Not sure that makes sense... __________________ BayTaper.com \| One man's multimedia journey through the San Francisco live jazz and creative music scene.

July 6th, 2010, 07:28 PM	#8
Brian Karr Regular Crew Join Date: Jan 2006 Location: Rockledge, Florida Posts: 36	So it sounds like there are three issues at play here: 1. Re-sampling the images when you are using the velocity curve to create slow motion. 2. Interlaced images are being converted to progressive. 3. Different frames rates are being used. 1. Anytime I use the velocity curve to slow down footage I disable re-sampling. John mentioned he does this around 15%, my preference is to always do it as I believe the image stays sharper, but its personal preference. 2. I agree with John that Ive found Vegas is pretty good at de-interlacing. In the project properties however, Ive usually set the de-interlace method to blend fields. Need to play with this as I have not used much interlaced footage lately. If de-interlace works than thats the setting to use! Im fairly sure its a lot easier to convert a progressive image to interlaced (basically split the fields), than it is to create progressive from interlaced. In the latter case, there is interpolation and/or other math going on to combine the fields to a progressive image. 3. How I work is I set the project properties to the frame rate I intend to deliver in. Vegas does a good job of dealing with different frame rates for you. If you use 24p, then pulldown will be implemented. As an example, I setup a lot of 1280x720p29.97 projects. I will use 1280x720p59.94 footage in it quite a bit and either slow it by half to 29.97 or even slower. I tend not to mix 24 fps footage with projects that are not 24p, although most of my interests are in fast moving subjects. i.e. Im usually looking to shoot as high a frame rate as possible, and always shoot progressive. __________________ Brian K www.vimeo.com/briankarr

July 4th, 2010, 08:37 AM	#3
Bruce Phung Major Player Join Date: Dec 2009 Location: Rochester,NY USA Posts: 285	Your video is 60i interlaced and you render your video in 30P. I think that is caused your problem. You should only render in 30P if your camera shoot 30P. Try to render 29,97 template. or wrong field order?

July 6th, 2010, 02:21 AM	#5
Patrick Janka Major Player Join Date: Jan 2010 Location: Orlando, FL Posts: 623	Brian, your solution got me halfway there. I also had to switch from Blend to Interpolate in De-interlacing method. Is disabling re-sampling something that has to be done every time I use interlaced footage? Also, what is the best way to combine clips of different frame rates? When adjusting the project settings it assumes you're only using one frame rate. In this case I used 60i, but the 30p stuff at the end didn't seem to get affected adversely. Is that because 30 is a multiple of 60? If I placed a 24fps clip in there would it have issues?

July 6th, 2010, 03:50 AM	#6
John Wiley Trustee Join Date: Oct 2008 Location: Byron Bay, Australia Posts: 1,155	My experience with Vegas is that it is terrible at handling interlaced footage but quite good at de-interlacing. I shoot everything at 50i currently, but always edit on a 25p Vegas timeline with the properties set to "field order: none" and "deinterlace method: Interpolate." It seems to do a good job of deinterlacing all my footage and getting rid of interlacing artifacts, but when I slow rootage down then all the "B" field gets thrown back into the mix to give you better resampling results. I've always left my clip poperties to "smart resampling" and unless I'm going to super slow motion (like 15% or something like that) it usally gives very acceptable results.