DAW/interface latency and sync'ing to video - live mixing

[Soniks]

Fellow gearslutz,

The following scenario is at hand:

Multi-camera, multi-mic event shoot streamed live over the web - Video out fed to video mixer then fed to streaming computer where it gets processed with a Digital Rapids card.

Audio fed from separate mics to FW interface then recorded/mixed live in Logic 8. The Output from Logic is then fed from the FW interface into the inputs that feed our streaming computer.


The problem - Logic's latency results in the audio being slightly behind the video. Is there a way to delay the video feed to match the output from Logic before it reaches the streaming computer? Any help would be greatly appreciated.

[spm_gl]

Hardware video delays are uncommon and expensive. So-called frame stores can do the job, but in your set-up you'll have a hard time getting video and audio to sync. Not sure what your streaming server can do, might want to check the manual, perhaps it has a video delay option somewhere.

[NorseHorse]

How reliable is your computer? Sounds like this gig is pretty important and I wouldn't want to risk any hiccups.

So... if it were me, I'd be running one feed to the computer (to mix and finesse later if that's what was required) and one feed to a mixer which would take care of the video mix. I'd send the feed from the mixer to the video folks (and the computer).

[chris319]

I would use an analog mixer.

[Roland]

You can use a digital mixer, just not ITB Logic system. With digital camera's there is likely to be an amount of delay, anything shorter with sound will be ok, just have to use audio delay.

regards


Roland

[Soniks]

Thanks for the replies everyone -

I agree, adding a mixer to the setup would be ideal and solve the latency problem by taking the Logic system out of the streaming chain. Send a separate feed to the streaming computer and another feed to the Logic system for recording purposes.

The issue is that Logic's EQ's, compressors and Limiters really come in handy during an event, and our rig needs to be as compact and as cost effective as possible. If we go the mixer route, then we need to ensure there are enough preamps, decent EQ on the channels, and possibly invest in a stereo compressor/limiter.

[videoteque]

Did you investigate your streaming program/server?? Does it give any possibilities to delay audio or video?? Video mixers have latency too!!!

The perfect way to do this would be to have the possibility to delay audio or video on the stream server. When doing tests you monitor the result in internet and adjust controls to make it perfect...

Fortunately for you, I think on internet sync expectations are much lower than on broadcast tv. So you can probably go +-5frames and nobody would complain!