a couple of minor fixes (oca_loadwav, audio playback)

antonrunov · Apr 6, 2019 · 4fce188 · 4fce188
1 parent 712425a
commit 4fce188
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Showing 5 changed files with 27 additions and 17 deletions.
diff --git a/scripts/utils/oca_loadwav.m b/scripts/utils/oca_loadwav.m
@@ -37,9 +37,9 @@ function oca_loadwav( filename, track=[], mono=false )
   end
   oca_track_setprop( "channels", ch, id );
 
-  t = 0;
+  t = oca_group_getcontext( {'oca_load_audio_start', 0} );
   res = 0;
-  block_sz = fs*10;
+  block_sz = fs*1000;
 
   while res < len
     x = wavread( filename, res + [1,min(block_sz,len-res)] )';

diff --git a/src/OcaAudioController.cpp b/src/OcaAudioController.cpp
@@ -1,5 +1,5 @@
 /*
-   Copyright 2013-2016 Anton Runov
+   Copyright 2013-2018 Anton Runov
 
    This file is part of Octaudio.
 
@@ -92,6 +92,7 @@ OcaAudioController::OcaAudioController()
 
   m_duplexStopRequested( false ),
   m_endOfData( false ),
+  m_startSkipCounter( 0 ),
 
   m_outputDevice( paNoDevice ),
   m_inputDevice( paNoDevice ),
@@ -218,10 +219,6 @@ double OcaAudioController::startPlayback( OcaTrackGroup* group, double t, double
       }
     }
 
-    if( result ) {
-      result = fillPlaybackBuffer();
-    }
-
     if( result ) {
       result = ( paNoError == Pa_StartStream( stream ) );
     }
@@ -247,6 +244,7 @@ double OcaAudioController::startPlayback( OcaTrackGroup* group, double t, double
         m_timer->start( 50 );
       }
       m_endOfData = false;
+      m_startSkipCounter = 0;
       m_playbackStream = stream;
       m_state = e_StatePlaying;
       flags = e_FlagStateChanged | e_FlagCursorChanged;
@@ -849,18 +847,26 @@ bool OcaAudioController::setDevice( QString dev_name, bool recording )
 
 bool OcaAudioController::fillPlaybackBuffer()
 {
-  bool result = false;
-  if( ( NULL != m_playbackBuffer ) && ( NULL != m_groupPlay ) ) {
-    bool duplex = ( m_groupPlay == m_groupRecording );
-    m_playbackCursor = m_groupPlay->readPlaybackData( m_playbackCursor,
-                                                      m_playbackStopPosition,
-                                                      m_playbackBuffer,
-                                                      m_sampleRate,
-                                                      duplex                );
-    result = ( 0 < m_playbackBuffer->getAvailableLength() );
+  if( ( NULL == m_playbackBuffer ) || ( NULL == m_groupPlay ) ) {
+    return false;
   }
 
-  return result;
+  // a tricky workaround for dropping initial parts of audio by some systems
+  // we are waiting a little bit before starting feedding the audio driver
+  if (4 > m_startSkipCounter) {
+    if (0 < m_playbackBuffer->getReadCount()) {
+      ++m_startSkipCounter;
+    }
+    return true;
+  }
+
+  bool duplex = ( m_groupPlay == m_groupRecording );
+  m_playbackCursor = m_groupPlay->readPlaybackData( m_playbackCursor,
+                                                    m_playbackStopPosition,
+                                                    m_playbackBuffer,
+                                                    m_sampleRate,
+                                                    duplex                );
+  return ( 0 < m_playbackBuffer->getAvailableLength() );
 }
 
 // -----------------------------------------------------------------------------

diff --git a/src/OcaAudioController.h b/src/OcaAudioController.h
@@ -123,6 +123,7 @@ class OcaAudioController : public OcaObject
 
     bool              m_duplexStopRequested;
     bool              m_endOfData;
+    int               m_startSkipCounter;
 
   protected:
     int   m_outputDevice;

diff --git a/src/OcaRingBuffer.cpp b/src/OcaRingBuffer.cpp
@@ -69,6 +69,7 @@ int OcaRingBuffer::read( float* data, int length )
   if( 0 < remainder ) {
     memset( data + length, 0, remainder * sizeof(float) );
   }
+  ++m_readCount;
   return length;
 }
 

diff --git a/src/OcaRingBuffer.h b/src/OcaRingBuffer.h
@@ -31,6 +31,7 @@ class OcaRingBuffer
     int write( float* data, int length );
     int getAvailableSpace() const { return ring( m_idxRead - m_idxWrite - 1 ); }
     int getAvailableLength() const { return ring( m_idxWrite - m_idxRead ); }
+    unsigned int getReadCount() const {return m_readCount;}
 
   protected:
     int ring( int idx ) const;
@@ -41,6 +42,7 @@ class OcaRingBuffer
 
     volatile int  m_idxRead;
     volatile int  m_idxWrite;
+    unsigned int          m_readCount;
 };
 
 #endif // OcaRingBuffer_h