Question / Help Sound sync OS X

[Vwdriver]

I have a Mac Pro 5,1 2010. It’s the 8 core model with 12 gb of ram. I’m using two blackmagic intensity pro pci cards. I’m capturing two cameras via hdmi. A Panasonic ag ac130 and a Sony hvr hd1000. The Sony doesn’t capture any sound at all. I have the sound board connected to the panasonic camera. I have a 1/8 cord from camera headphone jack to the mic input on the Mac Pro. The Sony matches the sound but the Panasonic is out of sync. Even though the sound is ran through that camera. Any ideas to try? I can’t capture the sound through the hdmi. It’s completely distorted.

 

[Narcogen]

If the gap is constant you can add a sync offset to a sound source in Edit > Advanced Audio Properties

 

[Vwdriver]

I don't know if the gap is constant, but if I add a sync offset, then the other camera will be out of sync. I am switching between cameras during the sermon. When I play it back, the Sony is aligned, but the Panasonic is not.

 

[Narcogen]

Then I would work on figuring out why audio through the HDMI is not working-- I'm guessing a format or sample rate mismatch of some sort. In the setup you describe there's no clock to sync signals to, and if the video signals themselves are not in sync then no matter what you do, you'll not be able to sync audio to both of them.

 

[Vwdriver]

I called BlackMagic and they suggest using the latest drivers. However, the first time I called them they told me not to use the latest drivers. Guess I will update and see how it goes. If that doesn't work, I will swap camera inputs and see if it follows the camera.

 

[Vwdriver]

I loaded the latest BM drivers. I swapped the slots that the BM cards were in and the problem stayed with the Panasonic. Im running XLR directly to the Panasonic. Panasonic to the audio input of the Mac via 3.5mm headphone jack. Audio is not in sync with the video, and even worse once it is recorded. Very odd that the sound matches the old Sony. Even though there isn't even a microphone on that camera. Is it possible that its because I can use the Radeon video card to offload the encoding? The CPU isn't taxed very much, but I know OBS doesn't support Mac hardware encoding for Radeon.

 

[Narcogen]

Offloading the encoding would help if the audio is going out of sync because your CPU is overloaded. But as you said, not an option under MacOS.

 

[Vwdriver]

I updated the drivers for the BM Intensity cards and it "seems" to have resolved my problem. My audio is now coming through HDMI like it should. I recorded two services with in sync sound. Hopefully this is fixed.