Exclusive audio device lock.

[romeojulietthotel]

Pothos takes an exclusive lock on the audio device. I can't think of a reason why it would need to do this. I can run multiple ffplay and they get along fine. But if I then start Pothos while an ffplay is running Pothos spews out errors constantly into the "Message Window".

On stdout I see this:

Expression 'parameters->channelCount <= maxChans' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 1513
Expression 'ValidateParameters( outputParameters, hostApi, StreamDirection_Out )' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 1845

If I start Pothos and then try to play audio via ffplay, ffplay cannot acquire an audio device due the exclusive lock by Pothos.

I read this:

http://portaudio.com/docs/v19-doxydocs/api_overview.html

I/O Methods: callback and read/write

PortAudio offers two methods for communicating audio data between an open Stream and your Application: (1) an asynchronous callback interface, where PortAudio calls a user defined callback function when new audio data is available or required, and (2) synchronous read and write functions which can be used in a blocking or non-blocking manner. You choose between the two methods when you open a Stream. The two methods are discussed in more detail below.

[guruofquality]

This issue was moved to pothosware/PothosAudio#4