comparison stk/src/RtWvOut.cpp @ 0:4606bd505630 tip

first import

+/***************************************************/
+/*! \class RtWvOut
+    \brief STK realtime audio (blocking) output class.
+
+    This class provides a simplified interface to RtAudio for realtime
+    audio output.  It is a subclass of WvOut.  This class makes use of
+    RtAudio's callback functionality by creating a large ring-buffer
+    into which data is written.  This class should not be used when
+    low-latency is desired.
+
+    RtWvOut supports multi-channel data in interleaved format.  It is
+    important to distinguish the tick() method that outputs a single
+    sample to all channels in a sample frame from the overloaded one
+    that takes a reference to an StkFrames object for multi-channel
+    and/or multi-frame data.
+
+    by Perry R. Cook and Gary P. Scavone, 1995--2014.
+*/
+/***************************************************/
+#pragma once
+
+#include "../include/RtWvOut.h"
+#include <cstring>
+
+namespace stk {
+
+// Streaming status states.
+enum { RUNNING, EMPTYING, FINISHED };
+
+// This function is automatically called by RtAudio to get audio data for output.
+int write( void *outputBuffer, void *inputBuffer, unsigned int nBufferFrames,
+           double streamTime, RtAudioStreamStatus status, void *dataPointer )
+{
+  return ( (RtWvOut *) dataPointer )->readBuffer( outputBuffer, nBufferFrames );
+}
+
+// This function does not block.  If the user does not write output
+// data to the buffer fast enough, previous data will be re-output
+// (data underrun).
+int RtWvOut :: readBuffer( void *buffer, unsigned int frameCount )
+{
+  unsigned int nSamples, nChannels = data_.channels();
+  unsigned int nFrames = frameCount;
+  StkFloat *input = (StkFloat *) &data_[ readIndex_ * nChannels ];
+  StkFloat *output = (StkFloat *) buffer;
+  long counter;
+
+  while ( nFrames > 0 ) {
+
+    // I'm assuming that both the RtAudio and StkFrames buffers
+    // contain interleaved data.
+    counter = nFrames;
+
+    // Pre-increment read pointer and check bounds.
+    readIndex_ += nFrames;
+    if ( readIndex_ >= data_.frames() ) {
+      counter -= readIndex_ - data_.frames();
+      readIndex_ = 0;
+    }
+
+    // Copy data from the StkFrames container.
+    if ( status_ == EMPTYING && framesFilled_ <= counter ) {
+      nSamples = framesFilled_ * nChannels;
+      unsigned int i;
+      for ( i=0; i<nSamples; i++ ) *output++ = *input++;
+      nSamples = (counter - framesFilled_) * nChannels;
+      for ( i=0; i<nSamples; i++ ) *output++ = 0.0;
+      status_ = FINISHED;
+      return 1;
+    }
+    else {
+      nSamples = counter * nChannels;
+      for ( unsigned int i=0; i<nSamples; i++ )
+        *output++ = *input++;
+    }
+
+    nFrames -= counter;
+  }
+
+  mutex_.lock();
+  framesFilled_ -= frameCount;
+  mutex_.unlock();
+  if ( framesFilled_ < 0 ) {
+    framesFilled_ = 0;
+    //    writeIndex_ = readIndex_;
+    oStream_ << "RtWvOut: audio buffer underrun!";
+    handleError( StkError::WARNING );
+  }
+
+  return 0;
+}
+
+
+RtWvOut :: RtWvOut( unsigned int nChannels, StkFloat sampleRate, int device, int bufferFrames, int nBuffers )
+  : stopped_( true ), readIndex_( 0 ), writeIndex_( 0 ), framesFilled_( 0 ), status_(0)
+{
+  // We'll let RtAudio deal with channel and sample rate limitations.
+  RtAudio::StreamParameters parameters;
+  if ( device == 0 )
+    parameters.deviceId = dac_.getDefaultOutputDevice();
+  else
+    parameters.deviceId = device - 1;
+  parameters.nChannels = nChannels;
+  unsigned int size = bufferFrames;
+  RtAudioFormat format = ( sizeof(StkFloat) == 8 ) ? RTAUDIO_FLOAT64 : RTAUDIO_FLOAT32;
+
+  // Open a stream and set the callback function.
+  try {
+    dac_.openStream( &parameters, NULL, format, (unsigned int)Stk::sampleRate(), &size, &write, (void *)this );
+  }
+  catch ( RtAudioError &error ) {
+    handleError( error.what(), StkError::AUDIO_SYSTEM );
+  }
+
+  data_.resize( size * nBuffers, nChannels );
+
+  // Start writing half-way into buffer.
+  writeIndex_ = (unsigned int ) (data_.frames() / 2.0);
+  framesFilled_ = writeIndex_;
+}
+
+RtWvOut :: ~RtWvOut( void )
+{
+  // Change status flag to signal callback to clear the buffer and close.
+  status_ = EMPTYING;
+  while ( status_ != FINISHED || dac_.isStreamRunning() == true ) Stk::sleep( 100 );
+  dac_.closeStream();
+}
+
+void RtWvOut :: start( void )
+{
+  if ( stopped_ ) {
+    dac_.startStream();
+    stopped_ = false;
+  }
+}
+
+void RtWvOut :: stop( void )
+{
+  if ( !stopped_ ) {
+    dac_.stopStream();
+    stopped_ = true;
+  }
+}
+
+void RtWvOut :: tick( const StkFloat sample )
+{
+  if ( stopped_ ) this->start();
+
+  // Block until we have room for at least one frame of output data.
+  while ( framesFilled_ == (long) data_.frames() ) Stk::sleep( 1 );
+
+  unsigned int nChannels = data_.channels();
+  StkFloat input = sample;
+  clipTest( input );
+  unsigned long index = writeIndex_ * nChannels;
+  for ( unsigned int j=0; j<nChannels; j++ )
+    data_[index++] = input;
+
+  mutex_.lock();
+  framesFilled_++;
+  mutex_.unlock();
+  frameCounter_++;
+  writeIndex_++;
+  if ( writeIndex_ == data_.frames() )
+    writeIndex_ = 0;
+}
+
+void RtWvOut :: tick( const StkFrames& frames )
+{
+#if defined(_STK_DEBUG_)
+  if ( data_.channels() != frames.channels() ) {
+    oStream_ << "RtWvOut::tick(): incompatible channel value in StkFrames argument!";
+    handleError( StkError::FUNCTION_ARGUMENT );
+  }
+#endif
+
+  if ( stopped_ ) this->start();
+
+  // See how much space we have and fill as much as we can ... if we
+  // still have samples left in the frames object, then wait and
+  // repeat.
+  unsigned int framesEmpty, nFrames, bytes, framesWritten = 0;
+  unsigned int nChannels = data_.channels();
+  while ( framesWritten < frames.frames() ) {
+
+    // Block until we have some room for output data.
+    while ( framesFilled_ == (long) data_.frames() ) Stk::sleep( 1 );
+    framesEmpty = data_.frames() - framesFilled_;
+
+    // Copy data in one chunk up to the end of the data buffer.
+    nFrames = framesEmpty;
+    if ( writeIndex_ + nFrames > data_.frames() )
+      nFrames = data_.frames() - writeIndex_;
+    if ( nFrames > frames.frames() - framesWritten )
+      nFrames = frames.frames() - framesWritten;
+    bytes = nFrames * nChannels * sizeof( StkFloat );
+    StkFloat *samples = &data_[writeIndex_ * nChannels];
+    StkFrames *ins = (StkFrames *) &frames;
+    memcpy( samples, &(*ins)[framesWritten * nChannels], bytes );
+    for ( unsigned int i=0; i<nFrames * nChannels; i++ ) clipTest( *samples++ );
+
+    writeIndex_ += nFrames;
+    if ( writeIndex_ == data_.frames() ) writeIndex_ = 0;
+
+    framesWritten += nFrames;
+    mutex_.lock();
+    framesFilled_ += nFrames;
+    mutex_.unlock();
+    frameCounter_ += nFrames;
+  }
+}
+
+} // stk namespace