On 02/29/2016 03:38 PM, Sebastian Gesemann wrote: > Hello fellow audio developers, > > I've started writing a software synthesizer in C++ (using SDL2 for > now) for kicks and giggles and ran into the problem of having the > event loop thread that listens for keyboard events communicate with > the audio callback. > > Are there any recommendations for how to pass real-time events (note > on, note off, etc) to such an audio callback? I figured, this is > already a solved problem and that I could benefit from your > experiences. Maybe you know of some nice open-source C++ queue > implementation that is suitable in such a situation. > > I could use some kind of "channel" (thread-safe bounded buffer > implemented using mutexes and condition variables) but I'm not sure > whether this is a good idea in this situation since the audio callback > function should avoid unnecessary delays.
Mutexes are not a good idea. http://www.rossbencina.com/code/real-time-audio-programming-101-time-waits-for-nothing The generic solution for cases like this is a lock-free ringbuffer. Then again, ideally you'll get both Audio and MIDI in the same callback to begin with. JACK provides this for example. > I've also looked into LV2. If I implemented the synthesizer as LV2 > plugin, I would get around having to solve the inter-thread > communication problem because it's the plugin host's responsibility. > But to be honest I've found this API to be a bit intimidating and I'm > not familiar with any LV2 host that would allow me to test such a > plugin. Any recommendations? Ardour? jalv, Carla, QTractor, Ardour.. A LV2 simple synth example can be found at http://lv2plug.in/book/#_sampler HTH, robin _______________________________________________ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
