View Full Version : I-Frame proxies w/ NanoFlash/HDX900


Stephen McCarthy
April 5th, 2010, 08:45 PM
Trying to make SD proxies of tape footage while shooting with HDX900 for use with Avid MC 4.0.5. Sending SD/SDI to nano running I-frame via down-converted SDI output. Video and audio are getting through and nano is detecting signal but not timecode. Am I doing something wrong in the settings or is this just an incompatibility with HDX's means of down-converting to SDI out? I know QT Long GOP might be satisfactory w/ Avid MC for 50mbps but this also seems to incur a lot of rendering/transcoding time. Any work-around?

Stephen McCarthy

Dave Chalmers
April 6th, 2010, 01:28 AM
Hi Stephen,

If you record 50Mbit IMX50 in MXF wrappers I would expect that to import and play fine in Avid 4.0.5 as it's a supported format.

I'll check that out today.

Dave

Dan Keaton
April 6th, 2010, 04:31 AM
Dear Stephen,

Timecode may not be present on your (SD) SDI signal.

You can obtain a timecode input cable for your nanoFlash, or a timecode plus remote control and tally light cable.

These are available from our dealers. nanoFlash.net - Free World Wide FedEx Express Shippingwith purchase of nanoFlashOrder online or email rick@nanoflash.net (http://www.nanoFlash.net) keeps these in stock.

One alternative is to use our HD proxy mode at 18 Mbps. You should have timecode via HD-SDI. (I would not use I-frame at very low bit-rates).

Scott Stoneback
April 6th, 2010, 01:27 PM
I am doing an SD shoot tomorrow and will be using the HDX900's SD downconverted SDI signal. So, it sounds like there is not embedded timecode in that signal, is that right?

The workaround is:

-set internal timecode in the Nano and record manually,
OR
-use a timecode/trigger cable

Is there a reason that the HDX900 does not output timecode with the downconverted SD-SDI signal? Is there a setting in the camera that fixes that, or is it always not present?

I am reading these posts without doing any testing myself... so I am assuming if I run this setup, I will not see timecode from the SDI signal. I will test later to be sure.

Dan Keaton
April 6th, 2010, 03:39 PM
Dear Scott,

We have had multiple reports of certain cameras not outputting timecode in SD-SDI.

We have a timecode cable that solves the problem.

It would be nice to know if timecode was actually present or not in the HDX900. According to the SMPTE Spec, it is optional.

Dusty Powers
April 6th, 2010, 06:40 PM
Dan:

If you are referring to seeing embedded TC from the HDX-900 in the SDI downconvert mode then I do not see it. Nor do I see it on the SDX-900 outputting through SDI. Just Audio and Video.

These are two cases where the TC / HDSDI/SDI cable to the NanoFlash would come in handy.

Dan Keaton
April 6th, 2010, 07:03 PM
Dear Dusty,

Yes, exactly.

Scott Stoneback
April 7th, 2010, 12:29 AM
Yep, HDX900 is definitely not embedding timecode in the SD SDI signal. I feel like a dropped frame.

Looks like I will be buying a cable soon...