summaryrefslogtreecommitdiff
path: root/portaudio/examples/paex_saw.c
diff options
context:
space:
mode:
Diffstat (limited to 'portaudio/examples/paex_saw.c')
-rw-r--r--portaudio/examples/paex_saw.c133
1 files changed, 133 insertions, 0 deletions
diff --git a/portaudio/examples/paex_saw.c b/portaudio/examples/paex_saw.c
new file mode 100644
index 0000000..caec0b0
--- /dev/null
+++ b/portaudio/examples/paex_saw.c
@@ -0,0 +1,133 @@
+/** @file paex_saw.c
+ @ingroup examples_src
+ @brief Play a simple (aliasing) sawtooth wave.
+ @author Phil Burk http://www.softsynth.com
+*/
+/*
+ * $Id$
+ *
+ * This program uses the PortAudio Portable Audio Library.
+ * For more information see: http://www.portaudio.com
+ * Copyright (c) 1999-2000 Ross Bencina and Phil Burk
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
+ * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
+ * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+/*
+ * The text above constitutes the entire PortAudio license; however,
+ * the PortAudio community also makes the following non-binding requests:
+ *
+ * Any person wishing to distribute modifications to the Software is
+ * requested to send the modifications to the original developer so that
+ * they can be incorporated into the canonical version. It is also
+ * requested that these non-binding requests be included along with the
+ * license above.
+ */
+
+#include <stdio.h>
+#include <math.h>
+#include "portaudio.h"
+#define NUM_SECONDS (4)
+#define SAMPLE_RATE (44100)
+
+typedef struct
+{
+ float left_phase;
+ float right_phase;
+}
+paTestData;
+
+/* This routine will be called by the PortAudio engine when audio is needed.
+** It may called at interrupt level on some machines so don't do anything
+** that could mess up the system like calling malloc() or free().
+*/
+static int patestCallback( const void *inputBuffer, void *outputBuffer,
+ unsigned long framesPerBuffer,
+ const PaStreamCallbackTimeInfo* timeInfo,
+ PaStreamCallbackFlags statusFlags,
+ void *userData )
+{
+ /* Cast data passed through stream to our structure. */
+ paTestData *data = (paTestData*)userData;
+ float *out = (float*)outputBuffer;
+ unsigned int i;
+ (void) inputBuffer; /* Prevent unused variable warning. */
+
+ for( i=0; i<framesPerBuffer; i++ )
+ {
+ *out++ = data->left_phase; /* left */
+ *out++ = data->right_phase; /* right */
+ /* Generate simple sawtooth phaser that ranges between -1.0 and 1.0. */
+ data->left_phase += 0.01f;
+ /* When signal reaches top, drop back down. */
+ if( data->left_phase >= 1.0f ) data->left_phase -= 2.0f;
+ /* higher pitch so we can distinguish left and right. */
+ data->right_phase += 0.03f;
+ if( data->right_phase >= 1.0f ) data->right_phase -= 2.0f;
+ }
+ return 0;
+}
+
+/*******************************************************************/
+static paTestData data;
+int main(void);
+int main(void)
+{
+ PaStream *stream;
+ PaError err;
+
+ printf("PortAudio Test: output sawtooth wave.\n");
+ /* Initialize our data for use by callback. */
+ data.left_phase = data.right_phase = 0.0;
+ /* Initialize library before making any other calls. */
+ err = Pa_Initialize();
+ if( err != paNoError ) goto error;
+
+ /* Open an audio I/O stream. */
+ err = Pa_OpenDefaultStream( &stream,
+ 0, /* no input channels */
+ 2, /* stereo output */
+ paFloat32, /* 32 bit floating point output */
+ SAMPLE_RATE,
+ 256, /* frames per buffer */
+ patestCallback,
+ &data );
+ if( err != paNoError ) goto error;
+
+ err = Pa_StartStream( stream );
+ if( err != paNoError ) goto error;
+
+ /* Sleep for several seconds. */
+ Pa_Sleep(NUM_SECONDS*1000);
+
+ err = Pa_StopStream( stream );
+ if( err != paNoError ) goto error;
+ err = Pa_CloseStream( stream );
+ if( err != paNoError ) goto error;
+ Pa_Terminate();
+ printf("Test finished.\n");
+ return err;
+error:
+ Pa_Terminate();
+ fprintf( stderr, "An error occurred while using the portaudio stream\n" );
+ fprintf( stderr, "Error number: %d\n", err );
+ fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( err ) );
+ return err;
+}