Init

DependentExtensions/portaudio_v18_1/pa_tests/patest_ringmix.c

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+/* $Id: patest_ringmix.c,v 1.1.1.1 2002/01/22 00:52:37 phil Exp $ */
+
+#include "stdio.h"
+#include "portaudio.h"
+/* This will be called asynchronously by the PortAudio engine. */
+static int myCallback( void *inputBuffer, void *outputBuffer,
+                       unsigned long framesPerBuffer, PaTimestamp outTime, void *userData )
+{
+    float *out = (float *) outputBuffer;
+    float *in  = (float *) inputBuffer;
+    float leftInput, rightInput;
+    unsigned int i;
+    if( inputBuffer == NULL ) return 0;
+    /* Read input buffer, process data, and fill output buffer. */
+    for( i=0; i<framesPerBuffer; i++ )
+    {
+        leftInput = *in++;      /* Get interleaved samples from input buffer. */
+        rightInput = *in++;
+        *out++ = leftInput * rightInput;            /* ring modulation */
+        *out++ = 0.5f * (leftInput + rightInput);   /* mix */
+    }
+    return 0;
+}
+/* Open a PortAudioStream to input and output audio data. */
+int main(void)
+{
+    PortAudioStream *stream;
+    Pa_Initialize();
+    Pa_OpenDefaultStream(
+        &stream,
+        2, 2,            /* stereo input and output */
+        paFloat32,  44100.0,
+        64,  0,          /* 64 frames per buffer, let PA determine numBuffers */
+        myCallback, NULL );
+    Pa_StartStream( stream );
+    Pa_Sleep( 10000 );    /* Sleep for 10 seconds while processing. */
+    Pa_StopStream( stream );
+    Pa_CloseStream( stream );
+    Pa_Terminate();
+    return 0;
+}