HDV, Kona LHe, & A/V Sync

[Stuart Ferreyra]

Call AJA again. I believe there is a delay issue and must be set manually.
I do my best not to work with HDV. Everytime we have, it’s been a hassle.

Stuart Ferreyra
Timecode Multimedia
President
Santa Monica, CA 90025
https://www.timecodemultimedia.com

[Brian Conner]

Playback Control Offset is set to 0 frames, but this thing seems to be happening during capture. It’s out of sync in QuickTime Player and in Aja’s VTR Exchange app.

I’m beginning to suspect the Kona LHe card itself, but that seemingly doesn’t make sense. Even so . . . .

I will be talking with Aja Tech Support first thing Monday morning, to find out what Hector had the client do to troubleshoot this when he spoke with them Friday afternoon.

Related question: When capturing through a Kona LHe, should the audio be 24 bit? It’s 48k sample rate 24 bit. Is that correct?

Brian Conner

[Vince Gaffney]

I had the exact same problem with a m15u. I finally switched to capture audio over f/w instead of analog into the LHe and now it’s fine – perfect sync. I spoke to AJA several times but we never figured it out.

vince

[Walter Biscardi]

I have a Sony M15U connected to our Kona 3 via the HD10AVA box and we have zero audio sync issues capturing to DVCPro HD. Sounds like you have a frame rate differential or something going on there.

I just checked a documentary we completed (over 500 shots captured) and it shows up as 24bit audio which is the default. All tapes shot 1080i/60 and captured at DVCPro HD 1080i/29.97 into FCP. No sync issues. We’ve completed three documentaries using the HDV to DVCPro HD workflow and it’s not a problem here. All audio and video captured using the Component / Analog Audio outputs of the deck through the converter to HD-SDI into our Kona 3.

Walter Biscardi, Jr.
https://www.biscardicreative.com
HD Editorial & Animation for Food Network’s “Good Eats”
HD Editorial for “Assignment Earth”

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

[Gary Adcock]

[Brian Conner] “Playback Control Offset is set to 0 frames, but this thing seems to be happening during capture. It’s out of sync in QuickTime Player and in Aja’s VTR Exchange app.”

What camera was this shot with and are your extracting 24p from the HDV stream. Without camera info all of this is moot,

IF the capture is off in both FCP and VtrEx then the tape is screwed up or some consumer HDV camera you are recording to has an offset built in.

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows

[Gary Adcock]

Additionally

how are you getting the audio into the kona card Via XLR or are you capturing via the differently.

more info brian.

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows

[Brian Conner]

Thank you, Vince and Walter.

The client called late last night to say she has captured several clips in a row without any sync issues. But she said she did them with Capture Now.

While I was on site just before the NAB, I experienced the sync problem with the first two clips we captured, but then it corrected itself the evening before I left from there for the NAB. I assumed it was resolved.

I’m not making that assumption, and told her to call me today to tell me if the sync issue returns after an overnight shutdown,or not.

I’ll also be calling Hector at Aja later this morning to get a recap of all the things he had her do last week.

BTW, Vince, I’ve never heard of taking the audio through FW while the video is going through the Kona card. I would have never figured audio and video would be in sync doing that. Heck, I didn’t even think it was possible to do that.

Brian Conner

[Brian Conner]

Thank you, Gary.

They are using a Sony Z1U. Please see my precious reply to Walter and Vince for more info.

Also, they are using a Sony UWP-C1 wireless mic. Playback from the M25U shows perfect sync. The sync problem only shows up after capture.

Brian Conner

[Brian Conner]

Forgot to answer the other question you asked, Gary. This is 29.97 all the way. No 24p at all.

[Brian Conner]

Audio signal path:

M25U analog audio outputs > Mackie 1402 > KL-Box > Kona LHe

Video signal path:

M25U HD analog component output > KL-Box component input > Kona LHe

However, we are having problems using the KL-Box. Aja has sent a second one that has the same problem. The HD-SDI Out does not send a signal to the Blackmagic HDLink box. When we switch to the LHe’s octopus cable, it works fine. Aja Tech Support is puzzled. At the moment, the octopus cable is connected in place of the KL-Box.

But WRT the sync issue, it makes no difference whether we use the KL-Box or the octopus cable.

BTW, even though previously I had a specific conversation with the client about 29.97 vs 24p WRT to the Z1U, I just now sent an Email to her asking for confirmation that the Z1U really is set for 29.97.