Kona Card to DVCProd HD working well?

[Andrew Young]

Since the transcoding scenario has its pitfalls (see transcoding and loss of sync) I am wondering how well the other edit-24p-on-a-Mac workaround is going for people. Specifically, I'm talking about capturing from the component outs of a BRHD50 deck and turning it into DVCProHD on the fly with a Kona LH card, while getting machine control and timecode via serial control.

Is this working well? Any issues? Does TC make it in OK and is it converted to 30 base? Are you stuck with 60p at this point?

Has anyone tried capturing as DV for offline and then recapturing as DCVPro HD once the cut is locked?

We're all Blackmagic here, so I am unable to evaluate this workflow. I would really appreciate any feedback from those who has used this setup.

[Robert Schaller]

You have more or less described my workflow:

shoot 720p24HDV with the HD100U, digitize via analog from a BR-50 deck to a Kona LH as DVCProHD59.94p using serial control and timecode. Timecode makes it in fine, and it seems to be repeatable (though I haven't had occaision to really check this on a frame level). Timecode, at this point, is 60fps, and the video has a 2,3 Varicam cadence.

Then, drag it onto a 23.98 DVCPro timeline. Most of of the time, it becomes 23.98p: every frame unique, and the timecode is 24 fps. The file is still 59.94p, unless you export it at 23.98, but it displays fine, and doesn't need rendering -- this must be the "Varicam-like" quality that JVC mentions; FCP is set up for the Varicam, and, mostly, the JVC follows admirably in its wake.

About 10% of the time, it produces a 12 fps image with every frame repeated. If this happens, I find that it is because (and don't ask me why) the cadence on the 60p clip is regular from beginning to end: that is, 2,3,2,3.....2,3,2,3. FCP only seems to interpret the 24p over 60p as 24p correctly if it both begins and ends out of cadence: for example, 1,2,3,2,3,2,3.....2,3,2,1. Any departure from regularity at the very beginning and very end seems to work. To fix a clip that is regular, just cut a frame from the satrt and from the end of a clip in its own 60p timeline, and export it as DVCProHD59.94p. Then, reimport the new clip, and it works as 24p. It's a weird workaround for a weird problem, but it works. I haven't sent my camera in for an upgrade yet, and wonder whether it fixes this.

I have not tried the SD-offline/recapture route. But I see no reason to think that it wouldn't work. The digitization seems repeatable, and my understanding of the serial control is that the timecode is on its own track and not embedded in the video stream, so it should be frame-accurately repeatable and not subject to long-GOP timing errors -- though, if anyone knows more about this, please pass it along!

[Eric Darling]

AJA has a whitepaper PDF that explains their recommended process for doing just this: http://www.aja.com/pdf/support/AJA_whitepaper_HDV.pdf

[Andrew Young]

Thanks Eric for the Aja info and thanks Robert for your very detailed response a while back. Both posts have been very helpful.

[Dave Beaty]

We have two Kona LH systems running and use the BR-HD50 to capture HDV 720p24 to DVCProHD 59.94 fps and the two analog audio channels without problems. The Kona also is able to output the sequences in in realtime and do realtime downconversions to the analog outputs. Great for the times where you are outputting to BetaSP for commercials or to a DVD recorder. We just keep the sequence in 59.94 and it maintains the 24p look. I suppose we use more disk space capturing at 59.94, but that's the only way it works.

Make sure the deck has 1.05 firmware, as the older versions produce deck software problems when batch capturing via serial control.

PS, Aja tech support is totally awesome. When I've had a problem, they've been there every time. They also have the LHe board for the newer G5's.

I shoot more and more in 30p and use the HDV codec, but the analog components are always there when I need 24p.

Dave Beaty