Audio "Sync offset" value set ignored when transition between "Media Sources"

[terjeh]

The set up is microphone + webcam connected directly to same PC as OBS, no issues with the set "sync offset" here, and the broadcast consist of switching between this and short movie clips.
Then sending all out trough NDI Out plugin to a different PC on the LAN. This creates a sinificant lag between picture and audio on the receiving end, and is fixed by identifying the delay and setting the value in "Advanced audio properties" on each source.
When i make a transition to the webcam/microphone scene, the value from "sync offset" is taken and everything is OK.
But when switching/transitioning to a (Video file) media source, the "Sync offset" value is ignored. I solved this during a recent broadcast by quickly enter into "Advanced Audio properties" after the transition and change the value 1 ms, e.g 300 ms to 301 ms, and then the dealay kicks in, and everything is in sync, until i transition to a new media source, and have to do the same thing again.

TL;DR
Sync offset value is not taken when changing to a scene with a Media Source.

 

[konsolenritter]

Did you compensate on the sending pc?

If the lag is encountered on the ndi receiving side, a lag between video and audio should be compensated there, not on the sending side. The lag should be equal for whatever is sent over the ndi transmission.

 

[terjeh]

Yes, the compensation was done on the sending pc (with obs). No compensation on the receiving end. I have no idea how compensation could be done there. On the receiving pc, video and audio was injected into teams with Newtek virtual input, and the result was monitored from a third pc as a attendee to the live event.
This method was chosen because the live event was created some time ago, with teams as producer, and it was decided that it was more important to keep the url to the event.
So i am a little unsure where the delay happened in the processing chain.