Capture from 1080i to 720p? at DVinfo.net

Kevin Shaw · February 14th, 2005, 07:46 AM

Is is possible to capture directly from a Sony HDV camera to the 720p editing format using Premiere Pro with Aspect HD? I can think of situations where I might want to do that.

Rob Lohman · February 14th, 2005, 07:56 AM

Not in p (progressive) at least, since the camera is interlaced only...

Kevin Shaw · February 14th, 2005, 09:11 AM

<<<Not in p (progressive) at least, since the camera is interlaced only... >>>

Understood, but since the source footage is being transcoded during capture anyway, is it possible that it could be deinterlaced at the same time? If not, could you capture and edit at "720i" and burn that to a disc for playback on computers? I've never heard of 720i as a functional video format, but can we create such a thing and have it be recognized by typical media players?

Rob Lohman · February 14th, 2005, 09:22 AM

Well, the "only" (depends on your definition etc.) difference between
interlaced and progressive in the digital realm is the time difference
between the fields (in interlaced).

I doubt de-interlace at HD resolutions is possible realtime, due to
required processing power for that. Even if it where possible the
quality would probably be far better if you processed it.

The same would go for 1080 -> 720 lines of resolution. Just capture
at the full resolution and downsample after the fact to your target
resolution with the best program/algorithm you can afford.

David Newman · February 14th, 2005, 10:12 AM

Rob is correct. It could be done yet it would be done better as a post-processing stage.

P.S. Where you thinking of 1080i60 to 720p60 or to 720p30 or 720p24? Just curious.

Kevin Shaw · February 14th, 2005, 11:37 AM

Thanks, I figured all this to be the case, but I thought I'd ask anyway. My hope was that maybe I could reduce the resolution to 720p30 since that's what I'm thinking of using for distribution, and then perhaps I could get better performance during editing. I'm concerned about trying to edit 1080i footage on a single-processor computer and don't know when I'll be able to upgrade to dual processors, so I'm trying to think of various compromises.

Maybe I should ask in more detail what performance I can expect using Aspect HD on a single 2.8 GHz processor with a decent hard drive setup. For example, could I possibly have two 1080i layers with one superimposed over the other as a PIP, do color correction on at least one of those layers and still have it play back in real time? If so then maybe I'm okay for now. I'll be trying all this soon for myself, but the more information I have ahead of time the better.

David Newman · February 14th, 2005, 12:17 PM

Yes you should be maybe to do a PiP over another video layer with a color corrector using Aspect HD on your PC. I can do this on my 2.8Ghz P4 (Prescott 800Mhz FSB) from a single 7200rpm drive.

Kevin Shaw · February 14th, 2005, 12:21 PM

Thanks David. Sounds like I really need to try it to see if I can get by for now. Any hints on optimizing Windows and/or Premiere Pro for working with Aspect HD?

David Newman · February 14th, 2005, 12:34 PM

Nothing unusual. Separate a drive or drives for video always help. Even sending the conformed audio on a different drive can help (audio on the system drive is fine.)

February 14th, 2005, 07:46 AM	#1
Kevin Shaw Inner Circle Join Date: Sep 2004 Location: Sacramento, CA Posts: 2,488	Capture from 1080i to 720p? Is is possible to capture directly from a Sony HDV camera to the 720p editing format using Premiere Pro with Aspect HD? I can think of situations where I might want to do that.

February 14th, 2005, 07:56 AM	#2
Rob Lohman RED Code Chef Join Date: Oct 2001 Location: Holland Posts: 12,514	Not in p (progressive) at least, since the camera is interlaced only... __________________ Rob Lohman, visuar@iname.com DV Info Wrangler & RED Code Chef Join the DV Challenge \| Lady X Search DVinfo.net for quick answers \| Buy from the best: DVinfo.net sponsors

February 14th, 2005, 09:22 AM	#4
Rob Lohman RED Code Chef Join Date: Oct 2001 Location: Holland Posts: 12,514	Well, the "only" (depends on your definition etc.) difference between interlaced and progressive in the digital realm is the time difference between the fields (in interlaced). I doubt de-interlace at HD resolutions is possible realtime, due to required processing power for that. Even if it where possible the quality would probably be far better if you processed it. The same would go for 1080 -> 720 lines of resolution. Just capture at the full resolution and downsample after the fact to your target resolution with the best program/algorithm you can afford. __________________ Rob Lohman, visuar@iname.com DV Info Wrangler & RED Code Chef Join the DV Challenge \| Lady X Search DVinfo.net for quick answers \| Buy from the best: DVinfo.net sponsors

February 14th, 2005, 10:12 AM	#5
David Newman CTO, CineForm Inc. Join Date: Jul 2003 Location: Cardiff-by-the-Sea, California Posts: 8,095	Rob is correct. It could be done yet it would be done better as a post-processing stage. P.S. Where you thinking of 1080i60 to 720p60 or to 720p30 or 720p24? Just curious. __________________ David Newman -- web: www.gopro.com blog: cineform.blogspot.com -- twitter: twitter.com/David_Newman

February 14th, 2005, 12:17 PM	#7
David Newman CTO, CineForm Inc. Join Date: Jul 2003 Location: Cardiff-by-the-Sea, California Posts: 8,095	Yes you should be maybe to do a PiP over another video layer with a color corrector using Aspect HD on your PC. I can do this on my 2.8Ghz P4 (Prescott 800Mhz FSB) from a single 7200rpm drive. __________________ David Newman -- web: www.gopro.com blog: cineform.blogspot.com -- twitter: twitter.com/David_Newman

February 14th, 2005, 09:11 AM	#3
Kevin Shaw Inner Circle Join Date: Sep 2004 Location: Sacramento, CA Posts: 2,488	<<<Not in p (progressive) at least, since the camera is interlaced only... >>> Understood, but since the source footage is being transcoded during capture anyway, is it possible that it could be deinterlaced at the same time? If not, could you capture and edit at "720i" and burn that to a disc for playback on computers? I've never heard of 720i as a functional video format, but can we create such a thing and have it be recognized by typical media players?

February 14th, 2005, 11:37 AM	#6
Kevin Shaw Inner Circle Join Date: Sep 2004 Location: Sacramento, CA Posts: 2,488	Thanks, I figured all this to be the case, but I thought I'd ask anyway. My hope was that maybe I could reduce the resolution to 720p30 since that's what I'm thinking of using for distribution, and then perhaps I could get better performance during editing. I'm concerned about trying to edit 1080i footage on a single-processor computer and don't know when I'll be able to upgrade to dual processors, so I'm trying to think of various compromises. Maybe I should ask in more detail what performance I can expect using Aspect HD on a single 2.8 GHz processor with a decent hard drive setup. For example, could I possibly have two 1080i layers with one superimposed over the other as a PIP, do color correction on at least one of those layers and still have it play back in real time? If so then maybe I'm okay for now. I'll be trying all this soon for myself, but the more information I have ahead of time the better.

February 14th, 2005, 12:21 PM	#8
Kevin Shaw Inner Circle Join Date: Sep 2004 Location: Sacramento, CA Posts: 2,488	Thanks David. Sounds like I really need to try it to see if I can get by for now. Any hints on optimizing Windows and/or Premiere Pro for working with Aspect HD?

February 14th, 2005, 12:34 PM	#9
David Newman CTO, CineForm Inc. Join Date: Jul 2003 Location: Cardiff-by-the-Sea, California Posts: 8,095	Nothing unusual. Separate a drive or drives for video always help. Even sending the conformed audio on a different drive can help (audio on the system drive is fine.) __________________ David Newman -- web: www.gopro.com blog: cineform.blogspot.com -- twitter: twitter.com/David_Newman