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Io HD realtime down-convert of 24P HD to 29.97 SD ?

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Steve Cassidy
Io HD realtime down-convert of 24P HD to 29.97 SD ?
on May 30, 2008 at 2:52:34 am

Does the IO/HD do realtime down-conversion to SD with pull-down insertion ?

I'm feeding it 1080 23.98 Psf HDcam (from an HDW-S280) with "1080sf23.98" as my primary format
and "525i29.97" as secondary with conversion set to "letterbox". (using "input passthrough")

I was expecting to see letterboxed SD at 29.97 with 2:3 pull-down coming out of the S-video and composite outputs. SOMETHING is coming out, but it isn't pretty... definitely not NTSC. The S-video
and composite outputs look identical on several different SD monitors.

What's the deal ? Am I expecting more than it's capable of ?

Steve Cassidy


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Jeremy Garchow
Re: Io HD realtime down-convert of 24P HD to 29.97 SD ?
on May 30, 2008 at 3:14:33 am

You have to right click on the analog triangle and choose "Secondary". You should then see a down convert node on the analog output pipe.

Your composite and s-video outputs should now be active.

Jeremy


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Steve Cassidy
Re: Io HD realtime down-convert of 24P HD to 29.97 SD ?
on May 30, 2008 at 3:34:57 am

Thanks Jeremy,
Yes, I've already done that and control panel is showing the downconvert icon in the path to the
analog output. ...Still getting garbage out.

I also tried setting my secondary digital output to downconvert to 525i29.97 and am getting strange things out there as well, monitoring with a Panasonic BT-LH900.

The primary HD-SDI output at 1080sf23.98 looks perfectly normal.

This all happening when I'm just trying to monitor my input signal using "input passthrough". If I capture a clip and drop it in a 23.98 Pro Res HQ timeline, ALL of the outputs look great on playback and the analog SD output does have 2:3 pulldown.

So, does the downconversion only work during playback, or should it work on input passthrough as well ?

thanks

Steve Cassidy





"http://www.cameracopters.com"
"http://www.airbornevideo.net"


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Jeremy Garchow
Re: Io HD realtime down-convert of 24P HD to 29.97 SD ?
on May 30, 2008 at 5:01:40 am

[Steve Cassidy] "So, does the downconversion only work during playback, or should it work on input passthrough as well ? "

You know, great question. I will have to check on that and get back to you.




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Steve Cassidy
Re: Io HD realtime down-convert of 24P HD to 29.97 SD ?
on May 30, 2008 at 5:09:53 am

OK.

According through the manual all of the outputs (including the down-converted ones) should be active
all of the time....so I'm stumped too. I'll wait to hear back from you on that before I flash the firmware.

Thanks for helping tonight.....gotta go to sleep now but I'll check in tomorrow.

Steve Cassidy


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Jeremy Garchow
Re: Io HD realtime down-convert of 24P HD to 29.97 SD ?
on May 30, 2008 at 3:38:30 pm

[Steve Cassidy] "I'll wait to hear back from you on that before I flash the firmware. "

No need to do that unnecessarily. Let me find out some things first.

Jeremy


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Jeremy Garchow
Re: Io HD realtime down-convert of 24P HD to 29.97 SD ?
on May 30, 2008 at 4:00:05 pm

I couldn't get this to work either. What does work is if you send 1080i to it, it will down convert. So, if your deck has an option for 3:2 pulldown, you can do it that way. Not sure if that will fit into your workflow, though. As you said, it does work if you play a psf file out, just not on input passthrough.


Jeremy


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Jeremy Garchow
Re: Io HD realtime down-convert of 24P HD to 29.97 SD ?
on May 30, 2008 at 6:25:25 pm

Alright.

It has been confirmed that this process won't work in E-E mode (as in input passthrough) for adding pulldown and it was never designed to. When you are NOT in e-e (such as playing a file) the pulldown pattern gets triggered from the file itself as the hardware has to read the file and frames in order to make new ones. That's why when working in FCP or playing a file though AJATV works and input passthrough does not as there's an actual start point to the pulldown pattern and the ioHD knows when to begin processing the frames.

In input pass through, the 23.98 data is simply being passed through and not processed. Unfortunately, monitors won't read 23.98 SD video. :(

Make sense?

Hope you got some rest.


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Steve Cassidy
Re: Io HD realtime down-convert of 24P HD to 29.97 SD ?
on May 30, 2008 at 8:29:49 pm

Jeremy,

Thanks very much for the concise answer ! It's not a problem for my workflow....I just got the unit
yesterday and wanted to make sure nothing was wrong with it.

And hey, that ProRes HQ output looks AMAZING ! ...very hard to tell the difference from the original
HDCAM field master.

Nice work Aja.


<**> Steve Cassidy




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Jeremy Garchow
Re: Io HD realtime down-convert of 24P HD to 29.97 SD ?
on May 30, 2008 at 8:51:33 pm

Yes, ProRes is pretty sweet, eh? And you are right, AJA did a nice job with the ioHD.

If you get a chance, you should capture 23.98 psf straight out of the camera and avoid any tape compression at all. Talk about nice output. It's fantastic.

Jeremy


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Steve Cassidy
Re: Io HD realtime down-convert of 24P HD to 29.97 SD ?
on May 31, 2008 at 3:46:38 am

I'd love to try 23.98 direct from the camera...but I do about 90% of my shooting from a cramped helicopter (using a Sony f950 inside a Cineflex system) and there's just not enough room in the
cockpit for a laptop and the IO HD. We need a bigger helicopter <**>

I'm still just marveling at how good the Pro Res HQ looks, considering that it's like 10% of the
file size of uncompressed HD. Radical. I can't wait to see how it holds up in color correction
and matte work.

Now, if they could just squeeze an Aja HD10MD3 into the IO HD case....

Steve Cassidy
"http://www.cameracopters.com"

"http://www.cameracopters.com"
"http://www.airbornevideo.net"


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Jeremy Garchow
Re: Io HD realtime down-convert of 24P HD to 29.97 SD ?
on May 31, 2008 at 2:51:14 pm

[Steve Cassidy] "We need a bigger helicopter "

Well, don't we all.


[Steve Cassidy] "I can't wait to see how it holds up in color correction
and matte work. "


CC holds up well, and in green screen (matte) work I have noticed that I have had to add a 422 smoother on it, but that might just be a function of the particular keyer that I use. I can still get great keys, though. Just as good as uncompressed.

Have fun.

Jeremy


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