Embedded Audio sync drift

I am using a Blackmagic 8K pro card on a project that takes 1080p SDI in with embedded audio. Then outputting a 1080p SDI with the audio re-embedded. We are seeing that the audio drifts around 20-30ms when we throw an A/V sync signal through the system. Is TouchDesigner able to keep the audio sync locked in place or is this small audio drift to be expected.

Since the audio gets separated from the video into a buffer on input, and then also buffered on the output, a little offset like this is to be expected unfortunately.

Thanks for the info Malcolm. Question, does adjusting the buffer length have any affect on the amount of drift or fluctuation on the audio sync?

Changing them shouldn’t affect any fluctuations. Certainly increasing the buffers will add delay to the audio signal, which I assume you are already accounting for somehow in this case if you are that close in sync?