Black Magic Duo 2 Audio Delay

#1

Hi all,

Having issues with audio delay in TD from BMD Decklink Duo 2 card.
Sync from the Audio Device In Chop is a long way behind the video, about 4 tenths of second behind.
I have tested the card setup with other programs on the computer, BMD Media Express is fine, Vmix is fine.

Searching the forum doesn’t get that many hits on audio sync issues with this setup. So either not many people are using the BMD cards, or not many people are having sync issues. (or my search skills are way off)

I have tried changing the buffer length, but this creates a choppier output.
Tried changing the format and rate settings in the aDI chop.
Tried changing the FPS of the project to match the video FPS.

I have a work around, bringing the audio in separately to the video via an audio interface. But this is not ideal, as it will also cause sync issues.

Any help or suggestions much appreciated.

Setup is:
TD ver - 2018.27550 and have tried 2019.10700
Windows 10 ver 1803 (os build 17134.556)
Alienware 15 R4 - Intel i9-8950HK, Ram 16GB - GeForce GTX 1080 Max-Q
Desktop Video ver 10.11.4
BMD Decklink Duo 2 - hd-sdi 4 way card

#2

Hi avd, I moved this to the bugs forum. Let me find a card here for testing.

#3

Hi Ben
Thanks very much. I will be very interested to hear how you get on.

#4

Sorry for the delay in answering. Right now this is a missing feature. We need to add support for the direct audio capture using Blackmagic’s SDK, which will allow the streams of data to be in sync.

#5

Hi Malcolm
Thanks for the reply.
Any estimate on how long it will take for the feature to be added?

#6

Just wondering on the timeline for adding this feature?

#7

Unfortunately we do not have it scheduled for development immediately so we can’t give an ETA right now. One option is Pro Support hours if that works for your project’s budget, you can contact us for an estimate in time it would take.

#8

I am trying to find a work around for this same issue.
Is there a way to delay the video signal to sync up the the Audio device in CHOP since the removing the delay on the audio isn’t an option?

#9

t.doyel,

You can use the texture3d and timemachine tops to create a video signal delay. Beware this can start to eat up a lot of gpu memory depending on the length of time and video format!

1 Like
#10

Hi Avd, & Derivative Team

Just wondering if there was any news on this ?

Am i right to assume the AJA Integration is the most robust at this stage for TD SDI In ?

Thanks.