Advice about using the audio thread

I have read a number of posts which recommend doing certain actions on the audio thread. In particular, I’m thinking of using the audio thread as a ‘master clock’ for sending midi messages to graphs of VST plugins. Can you tell me if I’ve got the right idea about this?

  1. AudioDeviceManager::addAudioCallback()
    Is this the right function to call to get access to the audio thread? I guess that the callback is called (at a high frequency?) on the audio thread.

  2. Is it OK to use the audio-callback just for timing?
    I don’t want to use the audio-callback to modify the audio stream. I just want to use it for timing. So is this still the right thing to use? Should I just set the audio-stream output data to zeros in my callback? Or should I be doing the timing of midi updates a different way?

  3. Can I send midi updates from the audio-thread?
    I have different ‘tracks’ each of which plays a different stream of midi messages via an audio-processor-graph of VST instruments and effects. Can I use a single audio callback as a ‘master clock’ to check whether it is time to update midi data? If it is, I would then send the midi updates by calling AudioProcessorPlayer::getMidiMessageCollector().addMessageToQueue()

If I’ve got this all wrong, could you point me in the right direction of what I should be doing? (If I’ve got it right, it would be good to have some confirmation of this. So don’t hold back from posting if the answers are Yes!)


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