Many users are probably using off-camera sound for live productions, for instance via separate hardware mixer or USB sound device.
A feature for automatic delay "sniffing" between two sources, for instance embedded audio with SDI or HDMI input and a separate sound device would make it easier to lip-sync separate video and audio. This would be a great addition regarding interviews etc.

The feature could be included in the audio settings behind the "cog wheel" of the to-be-synced audio source (USB sound card, for example). Below the existing audio delay value there could be a drop-down menu of the available video capture inputs, and the user could select the reference audio timing of those inputs. Then, vMix could capture a couple of seconds audio buffer from the respective audio and video inputs at intervals, and run a cross-correlation between those signals. (Location of the maximum value from the cross-correlation function gives the exact delay. This is rather trivial, considering that e.g. audio compressor is already implemented).

Any comments?


A simple example can be found at http://www.mathworks.se/...yed-signal-in-noise.html

I just saw the development announcement for vMix 13. As the upcoming version is receiving some major changes in the audio, could this feature request be considered at the same time?

I'm glad to give some theoretical assistance if necessary.

Any news about this feature, or any similar?