Sorry for not coming back here until now, but I have been unusually busy (good for business ;)
Generally I agree with Peter's comments, including that one regarding being constructive here and support the development of vMix as an already wonderful application!
One of the advantages with vMix is the in-built audio mixer. I am not the only one who have asked for the possibility to mix audio in VidBlaster (VB). As already noticed here, VB is designed to be used with an external mixer. But in some situations a very basic audio mixer is sufficient, eliminating the need of extra hardware. Imagine a ENG situation, with vMix it's super easy to mix audio from the camera with an external USB mike! But that type of relatively simple productions is not what we are discussing here.
Quote:The reason being in most live productions i've dealt with, all audio levels and configuration are set once
at the start of the show and then the automatic audio mixing is used when switching between sources
Interesting. I have learned, the hard way, that an external mixer is generally the best way of managing the audio. For many reasons, let me come back to those.
Meanwhile, I did re-visit the Teradek NAB 2014 nstudio tour (again congrats Martin!). Look, there is an external audio mixer at
http://youtu.be/OpYrOgYPHHk?t=5m46s. And I would be very surprised if no one touched it's sliders after the show started. I've stared until my eyes started to bleed at around 4m18sec in order to understand how audio was setup in vMix at NAB. That's why I began this topic with a question - how do you do it??? Because, maybe I missed something...
VB have for a long time had a feature where you for some modules (eg a video player) could define to which audio device the audio should be sent. As Peter points out, this is really nice as it allows you to channel that device to it's own input on an external mixer. Around a year ago the audio part in VB was redesigned (still demanding an external mixer). Among the new features for many modules (eg recorder and streamer) was the option to specify which audio device should be used as input. VB also support multiple streamers, which means one could stream to one channel with regular audio, and another with audio descriptions added (or one with Australian and the other with English ;).
Quote:Would it not be better to have them all going to a single audio channel in the mixer, rather than have the audio mixer operator hunt through every channel for the current clip that needs to be playing?
Absolutely, assuming that you only play one clip at a time. But with a little bit of crazy thinking, a whole new world opens up! (hang on, explained below)
Quote:To be clear, only video clips audio is what needs to be sent to the speaker output, all other types of audio can usually be sent to the mixer directly
My bad, when not sufficiently motivating the second request in "
Selectable audio routing for input modules". I just briefly mentioned "Video, FLASH/RTMP, and Streams".
Video clips are of course obvious. It might be far fetched to imagine two video inputs for which each has a separate audio route to an external mixer. But if possible, I think it might result in some interesting use. Flash is perhaps not the audio engineers favorite tool, but can contain audio. The possibility to separately manage audio output from different stream's inputs is even more interesting. Think of a Big brother like production, with multiple inputs coming over IP, where the audio mix is as important as the visual mix. In sum, being able to separately route audio out from all input types (that can contain audio) would mean everything from extremely useful to a creative spring board.
So, when using an external audio mixer, it's output needs to go back into vMix (or any PC based tool). Is that a problem? Yes, many...
To begin with, one of the biggest problem we have is ground loops. Hooking up a PC to a professional audio mixer in a public venue seems to always imply ground loops. Even worse, the noise is sometimes introduced in the last mile, that is, between the mixer's main out and the PC's input (eg Line in). That means, if you listen to the mixer's headphone output, you are clueless. If you can't hear what actually is going to be recorded, then you need to make a sample recording and listen to that recording. And that does not help if a new ground loop is introduced when a new camera, or some audio equipment, is added during a live production. Therefore, it is critical to be able to actually monitor what is being recorded/streamed. Both with ears and eyes. (The latter was possible in VidBlaster, before v3 and it's new audio design).
Explained differently. Why are there audio level monitors in vMix? Because they are a useful indiciation of that there is audio there (or not). But why are there only monitors showing what is coming in, when all external monitors also have output level monitors? Perhaps by a limitation in Windows?
We have also found it most important to being able to adjust the audio we get from a venue's house audio mixer. Both those that are operated by an audio engineer, and those that are automatically mixed (including low cut and compressed). This adjustment is typically needed frequently, immediately and in unexpected situations. Therefore we always connect via our own external audio mixer, as it's knob/slider is faster to operate than a mouse. Forthermore, this allows for simultaneous audio/video mix operation.
Peter has already pointed out that you typically need to monitor (hear) the audio before it is delayed. (One of the possible exceptions might be streamed inputs). Therefore, if it was possible to hear what is being recorded/streamed, then the audio delay should be introduced after the monitor signal.
On a side note. I am talking about audio routing. Other forum members have asked for more advanced audio mixing/processing capabilites inside vMix. My personal view is to keep vMix audio mixing/processing to a minimum. Delay, gain, and compression is already available and sufficient. The only one more thing that I consider being worth spending limited development time/resources on is low cut. But of course, if it was possible to use the output from a MultiTrack Recording software application (MTR, like ProTools, Cubase, etc) as an input to vMix - whow!!!! (given that vMix could route it's audio from input modules to the MTR's inputs ;)