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Downconvert/Field Issues-Upper vs Lower?

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Kevin Wild
Downconvert/Field Issues-Upper vs Lower?
on Aug 14, 2007 at 3:14:32 am

We've been using the following setup:

-We shoot using the Canon XL H1 to tape (HDV) using 24F
-We capture into FCP using a Convergent Design HD-ConnectLE using 1080i DVCProHD 29.97
-We edit a project in HD and then use Kona's realtime downconverter to output to Beta either letterboxed or center cut

Now, after downconverting, it seems like we have field issues due to the conversion of Upper Field dominance in HD to Lower Field in SD. It's pretty obvious on some graphic moves and even long dissolves that the that the fields are reversed or that something is wrong.

Anyone having this issue and have a remedy? How do people get around the fields being opposite from HD to SD when downconverting?

(There are also other issues with Kona's downconversion ghosting images. I've seen this posted sporadically on the boards and posted about it previously myself. I finally got the time to call their tech support and after much time on the phone, they finally verified that it IS there and is not right. Usually need a big monitor to see this...they didn't until they did a downconversion displayed on a Plasma. Hopefully an updated drive fixes this soon.)

Thanks for any thoughts!

Kevin
http://www.drawbridge.tv


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Kevin Wild
Re: Downconvert/Field Issues-Upper vs Lower?---ANYONE??
on Aug 15, 2007 at 4:00:19 am

Nobody is downconverting?? These seem like obvious bugs...I can't imagine we are the only ones having these problems.


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Santiago Gutierrez
Re: Downconvert/Field Issues-Upper vs Lower?---ANYONE??
on Aug 15, 2007 at 4:44:43 pm

I do this every week and have never had a problem with fields. I have edited in DVCPro HD 1080i and done this with no problems as well. Usually these days I'm using ProRes in HD. But I've never seen field problems on the downconvert and these shows are packed with graphics that are moving, so it would be obvious if there were field problems.
Santi



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AJA Sales Department
Re: Downconvert/Field Issues-Upper vs Lower?---ANYONE??
on Aug 15, 2007 at 4:50:20 pm

Hi Kevin,

Have you contacted our support department? They would more than happy to assist you in finding a solution for your issue.

They can reach via email at support@aja.com, or via phone (during business hours, US Pacific Time) at +1 (530) 271-3190.

Thank you,


--
AJA Video Systems
+1 (530) 274-2048 Intl.
(800) 251-4224 US
sales@aja.com


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cow
Kevin Wild
Re: Downconvert/Field Issues-Upper vs Lower?---ANYONE??
on Aug 15, 2007 at 5:06:40 pm

Sorry, AJA, I already spent 3-4 hours last week with the known downconvert issue. Santi-You are seeing this one, right? AJA acknowledged it when I was on the phone with them.

I'm thinking the interlacing issue might have to do with the 24F...but again, Santi, what is the deal with the upper versus lower? Is it converting the fields on the fly?

Thx.

Kevin


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Santiago Gutierrez
Re: Downconvert/Field Issues-Upper vs Lower?---ANYONE??
on Aug 15, 2007 at 5:24:37 pm

Hi Kevin,
I have seen some ghosting on lower thirds, but it's not really severe on my system, almost unnoticeable, And I still think the Kona 3's downconvert looks cleaner than than the downconvert from an HDW-F500 deck to a Digibeta. But I'm not starting from HDV footage. I'm going from HDCAM and DVCPro HD. I'd assume that the Kona 3 is doing the field conversion in hardware, but I don't know for sure. Maybe the issues you're seeing are from the 24F workflow from that Canon camera, but that's just a guess on my part.
Santi



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Kevin Wild
Re: Downconvert/Field Issues-Upper vs Lower?---ANYONE??
on Aug 15, 2007 at 5:32:54 pm

Just to be clear, the ghosting images we are seeing have nothing to do with HDV. It does it on the downconvert period, regardless of codec. I even tested uncompressed HD. Also to be clear, this is using the KonaLH. It's possible it's not an issue on the Kona 3. We have 3 LHe's and they all do it...as does the one at AJA tech support.

Yes, I'm starting to think the other interlacing issue might be Canon's weird-ass 24F! I will call AJA when I have downtime to see what they think on that one.

Thanks!

Kevin


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cowcowcowcowcow
gary adcock
Re: Downconvert/Field Issues-Upper vs Lower?---ANYONE??
on Aug 15, 2007 at 6:12:57 pm

First off Canon's 24F mode is not truly 24p, it is a bastardized 24 frame delivery much like the original Cine-Frame mode was on the Sony cameras, it uses a non standard cadence that cannot be extracted with the tools in FCP.


"Just to be clear, the ghosting images we are seeing have nothing to do with HDV. It does it on the downconvert period, regardless of codec. I even tested uncompressed HD."

Kevin, ever thought it may just be the interlacing of 1080? the" above and below" ghosting reminds me of standard interlace issues and if it took the Tech support guys at aja awhile to find your issue, maybe that could be the reason, since anytime you down convert to sd the image always takes a huge hit. Especially when going from progressive to interlaced delivery.




gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows


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Kevin Wild
Re: Downconvert/Field Issues-Upper vs Lower?---ANYONE??
on Aug 15, 2007 at 6:34:12 pm

Hey, Gary. Believe me, I'm quite familiar and frustrated with the ole' 24F. Had I known 2 years ago that 2 years later there still wouldn't be a deck that supported the camera with 24F, I would never have bought the $9,000 H1. We also have an A1...ugh, Canon really blew this, in my opinion. It's possible the one interlacing problem is related to this, but I'll have to test it more.

The ghosting isn't standard interlacing. It's a real problem. Text looks horrible...like I said, you can do the simplest way possible: just text on a background at 1080i and then downconvert and look at it on a big monitor. It's not good. I have faith that AJA will make it right soon. From the lack of others screaming about this :-), I would assume that this is only a Kona LHe bug, too, and not a Kona3 problem.

Thanks.

KW


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John Pale
Re: Downconvert/Field Issues-Upper vs Lower?---ANYONE??
on Aug 17, 2007 at 2:51:49 am

I see it on my Kona 2, for what its worth. have not found a workaround.


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cow
Kevin Wild
Re: Downconvert/Field Issues-Upper vs Lower?---ANYONE??
on Aug 15, 2007 at 5:25:38 pm

Sorry, that came across as obnoxious. AJA support was pretty great last week, though I do hope we hear that they have a fix to that downconvert ghosting soon.

(You can see this even if you do a simple text on a blank colored background in HD. Then, view the downconverted output on a large screen. The text will look ghosted above and below the text...it took AJA a while to see it, but they did once they put it on a large Plasma.)


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walter biscardi
Re: Downconvert/Field Issues-Upper vs Lower?---ANYONE??
on Aug 17, 2007 at 9:29:02 am

[Kevin Wild] "Nobody is downconverting?? These seem like obvious bugs...I can't imagine we are the only ones having these problems."

We downconvert almost every day using our Konas. We don't use the Convergent Design boxes. No issues with fields here at all.

Walter Biscardi, Jr.
http://www.biscardicreative.com
HD Editorial & Animation for Broadcast and independent productions.

All Things Apple Podcast! http://cowcast.creativecow.net/all_things_apple/index.html

Read my blog! http://blogs.creativecow.net/WalterBiscardi


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Kevin Wild
Re: Downconvert/Field Issues-Upper vs Lower?---ANYONE??
on Aug 17, 2007 at 11:23:58 am

Walter, do you guys use Kona 2' or 3's?

Again, this is absolutely a real bug; AJA took a while but acknowledged they are seeing it when I called them. But this was using LH's.



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gary adcock
Re: Downconvert/Field Issues-Upper vs Lower?---ANYONE??
on Aug 17, 2007 at 1:39:01 pm

kevin

I have 4 boards ( K2, K3, K3x and LHe) and I am not seeing it on my downconverts

what size text are you seeing this on,

and have you tried changing the vertical position a pixel or 2?

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows


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Kevin Wild
Re: Downconvert/Field Issues-Upper vs Lower?---ANYONE??
on Aug 17, 2007 at 1:47:16 pm

Sorry to keep dragging this out...

I have not tried that, but I seriously don't think that will help from the way the image is. I actually took a picture of it on my iPhone and sent it to Tech Support while talking with them. It's a real issue.

To recreate, just use either Boris or Text Tool to do any text on screen in an HD sequence and put it over a colored background. Then, choose downconvert (center cut or letterbox) and view on a large Plasma (we have 50" and 42" Panasonic and both showed it). The "ghosting" is a very soft shadowy shape of the text above and below it... It will NOT show up on the computer monitors...and is not clearly seen on smaller monitors.

It took a while for AJA Tech Support to see it...we went around and around. He at first didn't see it as he told me he was using smaller CRTs to test. He then got with a supervisor and checked it on a large monitor and called me back saying "yes, we see it now." So, again, it's real and not something I'm goofing up on my end. :-)

I really do NOT want to make this sound negative against AJA, though I hope we hear something soon about a fix for this. They were great on the phone support and called me back several times that day and kept at it until they saw what I was seeing.

Thx.

Kevin


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gary adcock
Re: Downconvert/Field Issues-Upper vs Lower?---ANYONE??
on Aug 17, 2007 at 2:01:24 pm

[Kevin Wild] "To recreate, just use either Boris or Text Tool to do any text on screen in an HD sequence and put it over a colored background. Then, choose downconvert (center cut or letterbox) and view on a large Plasma (we have 50" and 42" Panasonic and both showed it). The "ghosting" is a very soft shadowy shape of the text above and below it... It will NOT show up on the computer monitors...and is not clearly seen on smaller monitors."

OK
. you are looking at SD interlaced content on a HD plasma display. OF course it looks like mush- you are over rezing the content- virtually ALL SD text looks bad on plasma displays IMHO. you are letting the Plasma uprez your content to its native screen size.

Sorry --This is not a Kona Problem, this is operator error the native rez on your plasma is most likely 1280 x 768 and you are enlarging 720 x 486 content to fill it. You did not think of that as an issue?

What does it look like on a Broadcast monitor?? Plasmas should NEVER be used to judge SD content- they were not really made for that use.




gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows


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Kevin Wild
Re: Downconvert/Field Issues-Upper vs Lower?---ANYONE??
on Aug 17, 2007 at 2:07:36 pm

Gary, with all due respect, if the makers of the product say it is a bug, it is a bug.


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Kevin Wild
Re: Downconvert/Field Issues-Upper vs Lower?---ANYONE??
on Aug 17, 2007 at 2:11:15 pm

"this is operator error the native rez on your plasma is most likely 1280 x 768 and you are enlarging 720 x 486 content to fill it. You did not think of that as an issue?"

And yes, this is a little offensive after I have over and over explained my process and how AJA agree with me. This was not a case of "operator error." I covered my bases by spending 1/2 a day with tech support...thanks, though.

KW


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gary adcock
Re: Downconvert/Field Issues-Upper vs Lower?---ANYONE??
on Aug 17, 2007 at 3:10:52 pm

kevin

Sorry, however it was not until your post today that you mentioned that you were only seeing the issue on a plasma display- http://forums.creativecow.net/readpost/98/866477

You said AJA had to look at it on a plasma to see the issue, but only today did you mention that you were indeed looking at the plasma for your only ( my assumption) monitor.

Your plasma display is uprezing your incoming SD footage to meet its native resolution, guessing that you are on a 1280 x768 plasma (you have never mentioned what rez it is) that means that your SD content is being enlarged vertically about 0 .675%, not exactly a round number.

I firmly believe that is what you are seeing, the enlargement being done internally (of which you have no control) by the display itself, not the signal coming from your Kona Card.



gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows


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Kevin Wild
Re: Downconvert/Field Issues-Upper vs Lower?---ANYONE??
on Aug 17, 2007 at 3:17:08 pm

No, it is worse than that. And it is visible on our 20" CRT also, though not as easily seen.

It is difficult to describe a visual problem, so I don't think you are correctly "getting" what it is. That is why I sent a picture to AJA and the immediately said "that is not right" even for a plasma that is uprezzing.

Gary, I'd rather not keep this thread alive to only prove that this was not operator error or some ignorance on my part, so I'm done. In calling AJA, I thought I did that already. Hopefully AJA will chime in or let us know soon what the deal is. If I hear anything from them, I will post it. Thanks for trying...

Kevin
http://www.drawbridge.tv


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John Pale
Re: Downconvert/Field Issues-Upper vs Lower?---ANYONE??
on Aug 17, 2007 at 4:39:49 pm

Gary,
I see this too on with my Kona 2 on a CRT broadcast monitor.
I dont think what's going on is what you think it is. It may not be affecting everyone, but it is real.



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gary adcock
Re: Downconvert/Field Issues-Upper vs Lower?---ANYONE??
on Aug 17, 2007 at 6:20:47 pm

[John Pale] "Gary, I see this too on with my Kona 2 on a CRT broadcast monitor.
I dont think what's going on is what you think it is. It may not be affecting everyone, but it is real."


Thats interesting John,
in my testing the ghosting results were not seen on a CRT or my scopes (were it should show up), just on the uprezed output signal the plasma.

So I have been dissecting this from a differing point of view since I do not see the 'ghosting' on any of my output tests -- expect when the display itself is converting interlaced fields to frames like plasmas do. (plasma display technology uses an internal conversion that line doubles the interlaced fields to convert it to a progressive output)

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows


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Kevin Wild
Re: Downconvert/Field Issues-Upper vs Lower?---ANYONE??
on Aug 17, 2007 at 7:37:59 pm

Gary, I sent you a picture to your site email (info@...) so you can see what we're talking about and again, what AJA has admitted is a bug. This was taken from 37" LCD monitor. I have others that look even worse from a 42" and 50". It is a problem with the downconvert...

Kevin


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John Pale
Re: Downconvert/Field Issues-Upper vs Lower?---ANYONE??
on Aug 18, 2007 at 3:09:01 am

[gary adcock] "Thats interesting John,
in my testing the ghosting results were not seen on a CRT or my scopes (were it should show up), just on the uprezed output signal the plasma. "


I worked on a Kona 3 system today at a different facility and did NOT see it on their CRT. The bug may be limited to certain board revisions or hardware combinations. Should be a piece of cake to troubleshoot this :)









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gary adcock
Re: Downconvert/Field Issues-Upper vs Lower?---ANYONE??
on Aug 18, 2007 at 12:17:21 pm

[John Pale] "I worked on a Kona 3 system today at a different facility and did NOT see it on their CRT. The bug may be limited to certain board revisions or hardware combinations. Should be a piece of cake to troubleshoot this :)"

OK
so all of us are right... now lets see what's different.

I am on the most current versions of everything,
running on 3 Quad intels and a Dual 2.5 PCI-x

So that means
OS 10.4.10 / QT 7.2 / FCP 6.01 / Kona Build v4 (on all 4 machines)

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows


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Alexander Serpico
Re: Downconvert/Field Issues-Upper vs Lower?---ANYONE??
on Aug 18, 2007 at 8:35:12 pm

Just to add my experience, when downconverting either through the kona card or in FCP (ie. anamorphic to letterboxed 4x3), i always get a soft line doubled ghosted image also. I too have not yet figured a way around this. From my point of view this is not exactly a field issue, more of an interlacing issue (splitting hairs maybe). Trying to down convert with shake, just opens another pandora's box of frame resizing issues due to interlacing. I assume the trade off of in having the kona card or fcp software do this conversion so quickly is the ghosting, verses shake or compressor (in its default or most basic of settings for conversion) getting the horizontal ripping. I would love to pin point a solid way of doing this, and i admit to not spending enough time trying to solve this issue with tweaked settings in shake or compressor. also i have not tried to do this in the latest version of fcp, which i heard has better resizing (or maybe i just hope that is the case).



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John Pale
Re: Downconvert/Field Issues-Upper vs Lower?---ANYONE??
on Aug 19, 2007 at 3:18:28 am

[gary adcock] "I am on the most current versions of everything,
running on 3 Quad intels and a Dual 2.5 PCI-x

So that means
OS 10.4.10 / QT 7.2 / FCP 6.01 / Kona Build v4 (on all 4 machines)"


MacOSX 10.4.10/QT 7.2/FCP 6.0.1/Kona v4
PowerMac G5 Dual 2ghz/Kona 2




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Tom Brooks
Re: Downconvert/Field Issues-Upper vs Lower?---ANYONE??
on Aug 19, 2007 at 1:00:39 pm

Sounds like a field flip issue to me. I had an SD experience with that look a day or two ago. A colleague had an uncompressed sequence (720x486) with some DV (720x480) clips on it (He should have made a DV sequence). I changed the sequence setting to DV. It looked horrible. I looked at the motion tab on the clips and found that they were all set on "1" in the Y position instead of 0. Moved them back to 0--bingo, looks good again. Any chance you are getting a field flip because of incorrect Y position of the material?


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John Pale
Re: Downconvert/Field Issues-Upper vs Lower?---ANYONE??
on Aug 20, 2007 at 2:15:17 am

No. I did try to shift the fields and it did not help.

Anyway, I know what a field shift looks like and this is different looking.
Unfortunately I cant think of an effective way to post a screen shot.


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Tom Brooks
Re: Downconvert/Field Issues-Upper vs Lower?---ANYONE??
on Aug 20, 2007 at 3:20:38 pm

I did the quick title test and I see what you're talking about on the downconvert.

FCP 5.1.4, QT7.2, Kona LHe, Kona Control Panel V3.4



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