View Full Version : Deinterlace


Eloy Varela
August 16th, 2005, 09:16 AM
hello,

I would like you will explain me clearly the difference between progressive of camera ( native ) and progressive by software.
The people who uses HVR-Z1, what sofware do you suggest me for converting 1440x1080i to 1280x720p?

Thanks

Kyle Ringin
August 16th, 2005, 05:34 PM
Check this thread out for conversion methods:
http://www.dvinfo.net/conf/showthread.php?t=48352

It gives a link to this:
http://hdvforever.com/hdv/hdrhc1/to720p/

I'll let others fill you in on the native vs deinterlaced/resized question.

Cheers

Douglas Spotted Eagle
August 16th, 2005, 06:12 PM
Check this thread out for conversion methods:
http://www.dvinfo.net/conf/showthread.php?t=48352

It gives a link to this:
http://hdvforever.com/hdv/hdrhc1/to720p/

I'll let others fill you in on the native vs deinterlaced/resized question.

Cheers

The recipe referred to is null and useless if you use Sony Vegas, otherwise, it's a pretty good option.


Progressive in the camera means the footage is never interlaced at any point, it is always progressive.

Made from interlaced to progressive in post/software, means you start out with interlaced and end up with progressive.

Both formats have their benefits. Personally, I don't care for 24p or 30p acquired footage for anything that has a lot of movement, when captured with a 1/3" chip cam. But that's opinion, not a quantifiable position.
Interlaced captures fast movement better. Progressive is very smooth, or usually is. It's easy to convert interlaced to progressive, and vice-versa. If it's displayed on a CRT screen, it will be interlaced regardless of what the acquisition method is. If it's displayed on a computer screen or progressive television, it will be progressive taken from interlaced, if captured with an interlaced camera.
Eventually, all displays will be progressive. The grail is 1080p60, which isn't really an option for broadcast right now, but will be. The next best thing is 1080p30, which is doable right now. 1080i60 to 1080p30 is very nice looking, very smooth, if it's managed correctly.

John McGinley
August 16th, 2005, 07:08 PM
Speaking of converting from 60i to 24p, what's different in the new version of Gearshift? I have the 1.2.1 script and noticed the new one is $50.

Douglas Spotted Eagle
August 16th, 2005, 07:30 PM
Speaking of converting from 60i to 24p, what's different in the new version of Gearshift? I have the 1.2.1 script and noticed the new one is $50.

First, since you already own the application, you are entitled to a free download of the update.

Second, what's new is:
1. You can convert directly from the timeline, rather than converting entire tapes from the media pool or from the explorer. This saves tremendous amounts of conversion/rendering time.
2. Different options in the rendering queue
3. Auto-ripple of new files (user selected)

John McGinley
August 16th, 2005, 08:12 PM
Sweet, Free...yeah I think I can afford that. Thank you sir.

Kyle Ringin
August 16th, 2005, 10:01 PM
DSE,
How would you do the 1080i->720p conversion in Vegas to have the best quality?

Create a 720p project, place the footage on the timeline and apply a smart deinterlace filter?

(I don't have a HDV camera yet but am thinking about getting an FX1)

Thanks.

Douglas Spotted Eagle
August 16th, 2005, 10:08 PM
That's exactly how I'd do it. Are you coming to the VASST training in Melbourne next week? I can take a minute to show you this if you'd like.

Bjorn Moren
August 17th, 2005, 12:38 AM
Eventually, all displays will be progressive. The grail is 1080p60, which isn't really an option for broadcast right now, but will be.

Are you saying that 1080p60 is as good as 1080i120 (if available), even for fast paced action scenes?

I'm under the impression that we are far from framerates where an improvement in framerate would not give a visible difference. Perhaps at 1080p2000 (my guess) that would be true.

If given a limited bandwith, will not interlaced always be the preferred method, since it transfers action much better?

Or is it the editing benefits of progressive video you are referring to?

Barry Green
August 17th, 2005, 01:18 AM
Interlace will never be "better" than progressive video, at equivalent frame rates; the only benefit interlace has is when progressive just isn't fast enough. 60p gives better motion rendition than 60i -- you get just as many updates, but they're full frame updates, not split field updates. And since we already have 60p, and any increase in frame rate above 60 is pretty much undetectable to the brain/vision system, I don't expect we'll see too much faster anytime soon.

1080/60i will likely mark the end of interlace. I would strongly expect that all future development of high-def will center on progressive-scan displays. Nearly all high-definition televisions are natively progressive-scan. Of the six ATSC television formats accepted for broadcast, only one is interlace, the other five are progressive. I would bet that there will never be such a thing as 1080/120i.

Nigel Traill
August 17th, 2005, 02:50 AM
That's exactly how I'd do it. Are you coming to the VASST training in Melbourne next week? I can take a minute to show you this if you'd like.

Douglas,

You're visiting Australia next week? When are you in Sydney - and is it just Vegas you are speaking about?

I'm in Sydney. I'm interested in hearing you. I visited the VASST site but couldn't immediately find any reference to an Australian series of talks.

Nigel

Graeme Fullick
August 17th, 2005, 04:53 AM
Can I second that Spot.

I live in Newcastle - 200km north of SYdney, but might be able to get down to see you if you were there!

Graeme

Douglas Spotted Eagle
August 17th, 2005, 07:21 AM
visit the http://www.newmagic.com.au site for more information.
Look on the left hand side.

I'll be in Melbourne and Sydney, arriving there later today/your tomorrow.
Would be great to meet some of you!

re: 1080i120....what Barry said.

Eloy Varela
August 17th, 2005, 08:09 AM
Test:
record good soft.post
Sony HVR-Z1 1080i ------------------> 1280 x 720p (1)

record
JVC HD100 -------------------------> 1280 x 720p (2)

Wich one is the best quality image (1) or (2)?

I think it would be the second one, but is the difference very big??

Are you be able of understanding me?

Thanks for your reply guys.

Barry Green
August 17th, 2005, 11:44 AM
We do understand you. The answer is not yet clear. It would seem reasonable to expect a native 1280x720p signal to deliver the better 1280x720p final product, but there is much more to it.

First, do you want 24p or 30p? Then the JVC will give the better final result. But if you want the 60p look, the JVC cannot do it at all, and the converted Sony would do a better job.

Then there are other factors to consider, such as lens quality. For issues such as that, only side-by-side testing can deliver the actual true answer.

Eloy Varela
August 17th, 2005, 02:10 PM
Thanks to all for its answers.

Kyle Ringin
August 17th, 2005, 06:17 PM
Thanks Spot. I would come to your sessions - but I'd already booked flights for a holiday when I found out so I won't be there unfortunately.

What smart deinterlace filter would you use on the footage? I've used Mike Crash's one and it gives great results in the tests I've done, but I usually can't see much difference between most of the settings so I'm not really sure how to set it up. Are there any others that can be used directy in Vegas?

What would the workflow be? edit in cineform 1080i to allow for faster preview, then before render change the project settings and apply deinterlace? or would you deinterlace, resize and render all footage to cineform then edit natively at 720p?

Thanks

Eloy Varela
August 18th, 2005, 04:48 AM
hello,

I proved Cineform 3.2 for Vegas 6 and I liked.
It works well if framerate does not change (i.e. 1080 50i --->1280x720 25p). Also I proved Canopus Edius with such results( All with monitor 17 inch )
I respond to your questions?

Douglas Spotted Eagle
August 18th, 2005, 08:10 AM
Just as an FYI, CineForm is now up to it's 1.9 rev, you might want to download that. Some bug fixes, and some improvements to the speed workflow.

Bjorn Moren
August 19th, 2005, 04:10 AM
Interlace will never be "better" than progressive video, at equivalent frame rates; the only benefit interlace has is when progressive just isn't fast enough. 60p gives better motion rendition than 60i -- you get just as many updates, but they're full frame updates, not split field updates. And since we already have 60p, and any increase in frame rate above 60 is pretty much undetectable to the brain/vision system, I don't expect we'll see too much faster anytime soon.

re: 1080i120....what Barry said.

I agree that interlaced never will be better than progressive video at equvalent frame rates (60p vs 60i), that was not the subject of my post.

Since the most limiting factor today is data bandwidth, the only fair comparison would be to compare progressive with interlaced at the same bandwidths: 60i vs 30p. I think most people agree that 60i gives better fluidity of motion than 30p. (30p has it's uses though)

It's debatable how "pretty much undetectable" an increased frame rate beyond 60 FPS is for the human vision system. For instance take a look at this:

http://amo.net/NT/02-21-01FPS.html

If there is some evidence that 60p is the final FPS "grail" I would be happy to read about how and why the industry came to that conclusion. As I see it 1080i60 was developed as a pretty good trade off between image resolution and image update speed, given a limited and fixed bandwidth. My bet is that even 60p will lose ground to 120i and 120p or similar in the future.

Barry Green
August 19th, 2005, 09:49 AM
I'm referring to Douglas Trumbull's experiments with ShowScan, where he pretty much concluded there was no real going beyond 60fps (and, being film, that meant 60p). Any more than that was, in his opinion, just wasting film.

Bjorn Moren
August 19th, 2005, 10:52 AM
Thanks for the reply Barry.

I think Trumbull's experiments showed that it peaks around 72 FPS. But still this is an old experiment and only for printed film. By todays standards I think the experiment is obsolete.

Just try for yourself and play a 3D shooter game like Counter Strike or similar. Using a fast TFT screen, I would say there is a noticeable difference even up to 100 FPS. Why would that not apply to film making?

Another example: A standard TV set has a slightly flickering (as we percieve it) rendition of video, a 120 Hz TV set has less flickering.

Kyle Ringin
August 30th, 2005, 11:59 PM
What smart deinterlace filter would you use on the footage? I've used Mike Crash's one and it gives great results in the tests I've done, but I usually can't see much difference between most of the settings so I'm not really sure how to set it up. Are there any others that can be used directy in Vegas?

What would the workflow be? edit in cineform 1080i to allow for faster preview, then before render change the project settings and apply deinterlace? or would you deinterlace, resize and render all footage to cineform then edit natively at 720p?

Thanks

DSE, I know you will have been flat out the past few weeks, but can you give answers to the above when you get a chance?

Thanks.

Douglas Spotted Eagle
August 31st, 2005, 02:30 AM
DSE, I know you will have been flat out the past few weeks, but can you give answers to the above when you get a chance?

Thanks.

First, I don't do much of anything (OK, NOTHING) at 720p. None of our clients want it, all are interested in being future-ready/capable.
Second, I just use the internal tools for Vegas for deinterlacing. Mike's tools are great, but frankly, they're not any better than what Vegas (V6) does. I used his solution a lot in Vegas 5 however.
Depending on who the client is, we do many things in uncompressed YUV rather than CineForm, but we also have some clients that are very, very pleased with CineForm, and I prefer working in CineForm codec or working with proxy, as most of our stuff is 2-4 cams. Only problem with it is, I can't use it for SDI preview, so I use my third LCD with it. And I set the monitor props to deinterlace anyway.
If I WAS doing 720p output, I'd likely still edit in CineForm and then render to 720p from there, using the stock Vegas deinterlace settings.

Bill Binder
September 2nd, 2005, 11:04 AM
Second, I just use the internal tools for Vegas for deinterlacing. Mike's tools are great, but frankly, they're not any better than what Vegas (V6) does. I used his solution a lot in Vegas 5 however.

I used to use Crash's a lot in V5 also, but your quote here has me reconsidering now that I'm using V6. But I have a couple of questions now regarding this. First, I thought the Crash delacer was a motion-detection-based algorithm rather than Vegas's Blend and Interpolating algorithms? Do I have that wrong? Because, to me this might help with resolution for certain situations. My second question is that I think Mike has an updated version now that actually has different customizable settings. Have you tried used the new version of Mike's Delacer yet? And if so, any comments about how well it works?

Steven Bills
October 20th, 2006, 08:44 AM
DSE,
How would you do the 1080i->720p conversion in Vegas to have the best quality?

Create a 720p project, place the footage on the timeline and apply a smart deinterlace filter?


Thanks.

Where is this at? I cannot find it anywhere in Vegas 7.
Any help would be greatly appreciated.

Thanks,

Steven

Richard Hunter
October 20th, 2006, 12:24 PM
Hi Steve. It's a third party filter, but the good news is that it's free. You can get it at the link below, together with some others.

Richard

http://www.mikecrash.com/modules.php?name=Content&pa=showpage&pid=6

Steven Bills
October 21st, 2006, 11:28 AM
Thanks Richard, I'll give it a try.

SB

Alister Chapman
October 21st, 2006, 02:54 PM
Bjorn, one thing to consider is that at low bitrates, like the ones used for HD TV broadcast, interlace images show more artifacts than progressive images. Mpeg 2 and Mpeg 4 both work much better with progressive images when the bandwidth is being minimised. Combine that with the fact that progressive display technology is now both cheap and mature and there is avery strong argument for producing programmes in progressive.

Floris van Eck
October 22nd, 2006, 09:19 AM
Interesting discussion. JVC will soon launch the GY-HD200 and GY-HD250. Both camera's have 720p/50 and 720p/60. So how will that hold up against 1080i/50 and 1080i/60? Looks like 720p is also an option now.

Also in terms of making documentaries. Is it better to use an interlaced or a progressive format? I am really puzzled by all this information.

Mikko Lopponen
October 22nd, 2006, 10:09 AM
Bjorn, one thing to consider is that at low bitrates, like the ones used for HD TV broadcast, interlace images show more artifacts than progressive images. Mpeg 2 and Mpeg 4 both work much better with progressive images when the bandwidth is being minimised.

Mpeg2 actually handles interlaced material like progressive material, ie. it does NOT try to encode those interlace lines, but it sees the material as progressive. 30i becomes 60p, but at half the resolution.

So it doesn't matter to mpeg2 if the material is interlaced or not, the bandwidth is the same. As long as you flag it correctly, if you try to encode interlaced material as progressive then it will look very bad.