Environment:      Siren
Superclass:         Siren.PortAudioPort
Category:         MusicIO-Sound
Instance variables:   inChannels callbackBlock useProcess ioProcess
               ioSemaphore inClient outClients inBuffer outBuffer
               counter

SmartPortAudioPort is a more advanced IO port for PortAudio; it uses a Smalltalk process that sleeps on a semaphore that is signalled by the PortAudio callback. this allows one to synthesize sound interactively or to record into Siren sounds. The methods nextInBuffer and nextInBuffer are used to copy buffers or call synthesis clients.

Instance Variables:
   inChannels    # of input channels
   ioSemaphore semaphore sent from the low-level driver
   inClient    sample index> the sound being recorded into
   outClients Integer)> my playing sounds and their sample indices
   ioProcess my IO thread
   inBuffer sample buffer handed to PortAudio
   outBuffer sample buffer handed to PortAudio

play/record

callback
   Handle a callback from PortAudio; this is sent an an external callback

doIO
   Handle a callback from PortAudio; this is sent an an external callback through the class

nextInBuffer
   Get the next input buffer for the clients from the interface.

nextOutBuffer
   Get the next output buffer from the clients and sum it into my buffer for playing.

play: aSound
   Play the argument on the receiver over the DACs.

record: aSound
   Record into the argument via the receiver.

start: duration
   Start the receiver's IO loop for the given duration.

accessing

inChannels
   

inChannels: aValue
   

outClients
   

setInputDevice
   Set the port to use the default input device

open/close

close
   Close the receiver sound port

open
   Open the receiver sound port

initialize/release

initialize
   Answer an initialized version of the receiver.

MetaClass:         SmartAudioPort class

examples

testPlay
   Test playing a sound through the call-back interface

testRecord
   SmartAudioPort testRecord

callbacks

callback
   Forward the callback to an instance

instance creation

new
   Answer a new instance, or the singleton