comparison src/portaudio_20140130/examples/paex_sine_c++.cpp @ 124:e3d5853d5918

Current stable PortAudio source

+/** @file paex_sine.c
+	@ingroup examples_src
+	@brief Play a sine wave for several seconds.
+	@author Ross Bencina <[e-mail]>
+    @author Phil Burk <[e-mail]>
+*/
+/*
+ * $Id: paex_sine.c 1752 2011-09-08 03:21:55Z philburk $
+ *
+ * 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   (5)
+#define SAMPLE_RATE   (44100)
+#define FRAMES_PER_BUFFER  (64)
+
+#ifndef M_PI
+#define M_PI  (3.14159265)
+#endif
+
+#define TABLE_SIZE   (200)
+
+class Sine
+{
+public:
+    Sine() : stream(0), left_phase(0), right_phase(0)
+    {
+        /* initialise sinusoidal wavetable */
+        for( int i=0; i<TABLE_SIZE; i++ )
+        {
+            sine[i] = (float) sin( ((double)i/(double)TABLE_SIZE) * M_PI * 2. );
+        }
+
+        sprintf( message, "No Message" );
+    }
+
+    bool open(PaDeviceIndex index)
+    {
+        PaStreamParameters outputParameters;
+
+        outputParameters.device = index;
+        if (outputParameters.device == paNoDevice) {
+            return false;
+        }
+
+        outputParameters.channelCount = 2;       /* stereo output */
+        outputParameters.sampleFormat = paFloat32; /* 32 bit floating point output */
+        outputParameters.suggestedLatency = Pa_GetDeviceInfo( outputParameters.device )->defaultLowOutputLatency;
+        outputParameters.hostApiSpecificStreamInfo = NULL;
+
+        PaError err = Pa_OpenStream(
+            &stream,
+            NULL, /* no input */
+            &outputParameters,
+            SAMPLE_RATE,
+            FRAMES_PER_BUFFER,
+            paClipOff,      /* we won't output out of range samples so don't bother clipping them */
+            &Sine::paCallback,
+            this            /* Using 'this' for userData so we can cast to Sine* in paCallback method */
+            );
+
+        if (err != paNoError)
+        {
+            /* Failed to open stream to device !!! */
+            return false;
+        }
+
+        err = Pa_SetStreamFinishedCallback( stream, &Sine::paStreamFinished );
+
+        if (err != paNoError)
+        {
+            Pa_CloseStream( stream );
+            stream = 0;
+
+            return false;
+        }
+
+        return true;
+    }
+
+    bool close()
+    {
+        if (stream == 0)
+            return false;
+
+        PaError err = Pa_CloseStream( stream );
+        stream = 0;
+
+        return (err == paNoError);
+    }
+
+
+    bool start()
+    {
+        if (stream == 0)
+            return false;
+
+        PaError err = Pa_StartStream( stream );
+
+        return (err == paNoError);
+    }
+
+    bool stop()
+    {
+        if (stream == 0)
+            return false;
+
+        PaError err = Pa_StopStream( stream );
+
+        return (err == paNoError);
+    }
+
+private:
+    /* The instance callback, where we have access to every method/variable in object of class Sine */
+    int paCallbackMethod(const void *inputBuffer, void *outputBuffer,
+        unsigned long framesPerBuffer,
+        const PaStreamCallbackTimeInfo* timeInfo,
+        PaStreamCallbackFlags statusFlags)
+    {
+        float *out = (float*)outputBuffer;
+        unsigned long i;
+
+        (void) timeInfo; /* Prevent unused variable warnings. */
+        (void) statusFlags;
+        (void) inputBuffer;
+
+        for( i=0; i<framesPerBuffer; i++ )
+        {
+            *out++ = sine[left_phase];  /* left */
+            *out++ = sine[right_phase];  /* right */
+            left_phase += 1;
+            if( left_phase >= TABLE_SIZE ) left_phase -= TABLE_SIZE;
+            right_phase += 3; /* higher pitch so we can distinguish left and right. */
+            if( right_phase >= TABLE_SIZE ) right_phase -= TABLE_SIZE;
+        }
+
+        return paContinue;
+
+    }
+
+    /* 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 paCallback( const void *inputBuffer, void *outputBuffer,
+        unsigned long framesPerBuffer,
+        const PaStreamCallbackTimeInfo* timeInfo,
+        PaStreamCallbackFlags statusFlags,
+        void *userData )
+    {
+        /* Here we cast userData to Sine* type so we can call the instance method paCallbackMethod, we can do that since 
+           we called Pa_OpenStream with 'this' for userData */
+        return ((Sine*)userData)->paCallbackMethod(inputBuffer, outputBuffer,
+            framesPerBuffer,
+            timeInfo,
+            statusFlags);
+    }
+
+
+    void paStreamFinishedMethod()
+    {
+        printf( "Stream Completed: %s\n", message );
+    }
+
+    /*
+     * This routine is called by portaudio when playback is done.
+     */
+    static void paStreamFinished(void* userData)
+    {
+        return ((Sine*)userData)->paStreamFinishedMethod();
+    }
+
+    PaStream *stream;
+    float sine[TABLE_SIZE];
+    int left_phase;
+    int right_phase;
+    char message[20];
+};
+
+
+/*******************************************************************/
+int main(void);
+int main(void)
+{
+    PaError err;
+    Sine sine;
+
+    printf("PortAudio Test: output sine wave. SR = %d, BufSize = %d\n", SAMPLE_RATE, FRAMES_PER_BUFFER);
+    
+    err = Pa_Initialize();
+    if( err != paNoError ) goto error;
+
+    if (sine.open(Pa_GetDefaultOutputDevice()))
+    {
+        if (sine.start())
+        {
+            printf("Play for %d seconds.\n", NUM_SECONDS );
+            Pa_Sleep( NUM_SECONDS * 1000 );
+
+            sine.stop();
+        }
+
+        sine.close();
+    }
+
+    Pa_Terminate();
+    printf("Test finished.\n");
+    
+    return err;
+
+error:
+    Pa_Terminate();
+    fprintf( stderr, "An error occured while using the portaudio stream\n" );
+    fprintf( stderr, "Error number: %d\n", err );
+    fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( err ) );
+    return err;
+}