is resizing HDV CF25 to SD (PAL) loseless? at DVinfo.net

Anton Galimzyanov · October 6th, 2006, 06:53 PM

Hi everyone,

Speaking of resizing the video from Z1 camera, mode Cineframe 25.
I'm pretty sure there's no visual difference between cineframe 1440x1080 and 1280x720. Let's say, my final destination is PAL DVD. Well, no keying, rotoscoping, fX etc on a timeline (just CC, cuts and fades). Well-known test shows that the vertical limit of Z1 in CF mode is about 540 lines (less than PAL video definition!). So my question is: should I resize CF to 1280x720, edit and then resize the final AVI to SD; or should I resize directly to 720x576 on a capture (thus saving disc space and maybe one step of conversion' degradation)?

Thanx,

David Newman · October 6th, 2006, 08:23 PM

I would edit at 1280x720.

Anton Galimzyanov · October 7th, 2006, 04:48 AM

David, I would too - somehow I feel it would be a better way to go.
But could you give reason for editing in 1280x720?
One of them is, as I think, a native real-time mode in PPro, the second is an increased horizontal resolution - it's always better to stay in higher resolutions during colorizing/editing).. Am I right?

David Newman · October 7th, 2006, 10:00 AM

Native is not the reason, as you are resizing form 1440x1080 to 1280x720 you are no longer native, so no point in taking an MPEG hit. In CineForm AVI the 1280x720 will have a small disk footprint and higher performance (without a resolution penalty as you shot in CineFrame 25.) Edit in HD gives you the oversampling needed to allow you to frame re-crop for you SD production. Plus you will have an HD master for a little future proofing.

Anton Galimzyanov · October 7th, 2006, 02:30 PM

by "native real-time mode" I meant cineform's preset, of course, not a Premiere's mpeg editing.

Thanks again for reply. I'll be working at 1280x720, definitely!

Anton Galimzyanov · October 9th, 2006, 10:52 AM

Quote:

Originally Posted by David Newman

The Cineframe mode only resolves about 540 lines, so either 720p or 1080p presentation with have about 540 lines. So converting 1440x1080 to 1280x720 doesn't lose anything.

Hmm.. I've done converting 1440x1080 (Cineframe25) to 1280x720 via HD Link and then via After Effects. And I've done converting 1440x1080 to 720x576 (SD) as well. And the result in both cases is the same: AE gives more crisp video, definitely! Well, I've been told that sometimes downconversion from HD to SD introduce some flickering, but I tried 5 different TV sets - everything plays perfectly.
So Alex Raskin is right - if the final result is DVD, try After Effects.

Could you comment it, David?

David Newman · October 9th, 2006, 03:40 PM

Which Aspect HD version?

Anton Galimzyanov · October 9th, 2006, 11:06 PM

the last one - build 69

David Newman · October 9th, 2006, 11:20 PM

That's a pity now we are going to have to determine why. :) We are using Lanczos scalers, which look excellent for most image sources. "Crisp"-ness of AE, may mean it has more sharpening.

Anton Galimzyanov · October 10th, 2006, 12:06 AM

Yes, AE does produce more sharpening. Maybe in case of Cinealta's files it's not too good (aliasing/flickering artefacts), but in the world of cheap HDV cameras soft "semi-HD" videos look even softer.

October 6th, 2006, 06:53 PM	#1
Anton Galimzyanov Regular Crew Join Date: Feb 2005 Location: Moscow, Russia Posts: 53	is resizing HDV CF25 to SD (PAL) loseless? Hi everyone, Speaking of resizing the video from Z1 camera, mode Cineframe 25. I'm pretty sure there's no visual difference between cineframe 1440x1080 and 1280x720. Let's say, my final destination is PAL DVD. Well, no keying, rotoscoping, fX etc on a timeline (just CC, cuts and fades). Well-known test shows that the vertical limit of Z1 in CF mode is about 540 lines (less than PAL video definition!). So my question is: should I resize CF to 1280x720, edit and then resize the final AVI to SD; or should I resize directly to 720x576 on a capture (thus saving disc space and maybe one step of conversion' degradation)? Thanx,

October 6th, 2006, 08:23 PM	#2
David Newman CTO, CineForm Inc. Join Date: Jul 2003 Location: Cardiff-by-the-Sea, California Posts: 8,095	I would edit at 1280x720. __________________ David Newman -- web: www.gopro.com blog: cineform.blogspot.com -- twitter: twitter.com/David_Newman

October 7th, 2006, 10:00 AM	#4
David Newman CTO, CineForm Inc. Join Date: Jul 2003 Location: Cardiff-by-the-Sea, California Posts: 8,095	Native is not the reason, as you are resizing form 1440x1080 to 1280x720 you are no longer native, so no point in taking an MPEG hit. In CineForm AVI the 1280x720 will have a small disk footprint and higher performance (without a resolution penalty as you shot in CineFrame 25.) Edit in HD gives you the oversampling needed to allow you to frame re-crop for you SD production. Plus you will have an HD master for a little future proofing. __________________ David Newman -- web: www.gopro.com blog: cineform.blogspot.com -- twitter: twitter.com/David_Newman

October 9th, 2006, 03:40 PM	#7
David Newman CTO, CineForm Inc. Join Date: Jul 2003 Location: Cardiff-by-the-Sea, California Posts: 8,095	Which Aspect HD version? __________________ David Newman -- web: www.gopro.com blog: cineform.blogspot.com -- twitter: twitter.com/David_Newman

October 9th, 2006, 11:20 PM	#9
David Newman CTO, CineForm Inc. Join Date: Jul 2003 Location: Cardiff-by-the-Sea, California Posts: 8,095	That's a pity now we are going to have to determine why. :) We are using Lanczos scalers, which look excellent for most image sources. "Crisp"-ness of AE, may mean it has more sharpening. __________________ David Newman -- web: www.gopro.com blog: cineform.blogspot.com -- twitter: twitter.com/David_Newman

October 7th, 2006, 04:48 AM	#3
Anton Galimzyanov Regular Crew Join Date: Feb 2005 Location: Moscow, Russia Posts: 53	David, I would too - somehow I feel it would be a better way to go. But could you give reason for editing in 1280x720? One of them is, as I think, a native real-time mode in PPro, the second is an increased horizontal resolution - it's always better to stay in higher resolutions during colorizing/editing).. Am I right?

October 7th, 2006, 02:30 PM	#5
Anton Galimzyanov Regular Crew Join Date: Feb 2005 Location: Moscow, Russia Posts: 53	by "native real-time mode" I meant cineform's preset, of course, not a Premiere's mpeg editing. Thanks again for reply. I'll be working at 1280x720, definitely!

October 9th, 2006, 11:06 PM	#8
Anton Galimzyanov Regular Crew Join Date: Feb 2005 Location: Moscow, Russia Posts: 53	the last one - build 69

October 10th, 2006, 12:06 AM	#10
Anton Galimzyanov Regular Crew Join Date: Feb 2005 Location: Moscow, Russia Posts: 53	Yes, AE does produce more sharpening. Maybe in case of Cinealta's files it's not too good (aliasing/flickering artefacts), but in the world of cheap HDV cameras soft "semi-HD" videos look even softer.