/** @file patest_prime.c	@ingroup test_src	@brief Test stream priming mode.	@author Ross Bencina http://www.audiomulch.com/~rossb*//* * $Id: patest_prime.c 1097 2006-08-26 08:27:53Z rossb $ * * 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"#include "pa_util.h"#define NUM_BEEPS           (3)#define SAMPLE_RATE         (44100)#define SAMPLE_PERIOD       (1.0/44100.0)#define FRAMES_PER_BUFFER   (256)#define BEEP_DURATION       (400)#define IDLE_DURATION       (SAMPLE_RATE*2)      /* 2 seconds */#define SLEEP_MSEC          (50)#define STATE_BKG_IDLE      (0)#define STATE_BKG_BEEPING   (1)typedef struct{    float        leftPhase;    float        rightPhase;    int          state;    int          beepCountdown;    int          idleCountdown;}paTestData;static void InitializeTestData( paTestData *testData ){    testData->leftPhase = 0;    testData->rightPhase = 0;    testData->state = STATE_BKG_BEEPING;    testData->beepCountdown = BEEP_DURATION;    testData->idleCountdown = IDLE_DURATION;}/* 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;    int result = paContinue;    /* supress unused parameter warnings */    (void) inputBuffer;    (void) timeInfo;    (void) statusFlags;    for( i=0; i<framesPerBuffer; i++ )    {        switch( data->state )        {        case STATE_BKG_IDLE:            *out++ = 0.0;  /* left */            *out++ = 0.0;  /* right */            --data->idleCountdown;                        if( data->idleCountdown <= 0 ) result = paComplete;            break;        case STATE_BKG_BEEPING:            if( data->beepCountdown <= 0 )            {                data->state = STATE_BKG_IDLE;                *out++ = 0.0;  /* left */                *out++ = 0.0;  /* right */            }            else            {                /* Play sawtooth wave. */                *out++ = data->leftPhase;  /* left */                *out++ = data->rightPhase;  /* right */                /* Generate simple sawtooth phaser that ranges between -1.0 and 1.0. */                data->leftPhase += 0.01f;                /* When signal reaches top, drop back down. */                if( data->leftPhase >= 1.0f ) data->leftPhase -= 2.0f;                /* higher pitch so we can distinguish left and right. */                data->rightPhase += 0.03f;                if( data->rightPhase >= 1.0f ) data->rightPhase -= 2.0f;            }            --data->beepCountdown;            break;        }    }        return result;}/*******************************************************************/static PaError DoTest( int flags ){    PaStream *stream;    PaError    err;    paTestData data;    PaStreamParameters outputParameters;    InitializeTestData( &data );           outputParameters.device = Pa_GetDefaultOutputDevice();    outputParameters.channelCount = 2;    outputParameters.hostApiSpecificStreamInfo = NULL;    outputParameters.sampleFormat = paFloat32;    outputParameters.suggestedLatency = Pa_GetDeviceInfo( outputParameters.device )->defaultHighOutputLatency;    /* Open an audio I/O stream. */    err = Pa_OpenStream(        &stream,        NULL,                         /* no input */        &outputParameters,        SAMPLE_RATE,        FRAMES_PER_BUFFER,            /* frames per buffer */        paClipOff | flags,      /* we won't output out of range samples so don't bother clipping them */        patestCallback,        &data );    if( err != paNoError ) goto error;    err = Pa_StartStream( stream );    if( err != paNoError ) goto error;    printf("hear \"BEEP\"\n" );    fflush(stdout);    while( ( err = Pa_IsStreamActive( stream ) ) == 1 ) Pa_Sleep(SLEEP_MSEC);    if( err < 0 ) goto error;    err = Pa_StopStream( stream );    if( err != paNoError ) goto error;    err = Pa_CloseStream( stream );    if( err != paNoError ) goto error;    return err;error:    return err;}/*******************************************************************/int main(void);int main(void){    PaError    err = paNoError;    int        i;    /* Initialize library before making any other calls. */    err = Pa_Initialize();    if( err != paNoError ) goto error;        printf("PortAudio Test: Testing stream playback with no priming.\n");    printf("PortAudio Test: you should see BEEP before you hear it.\n");    printf("BEEP %d times.\n", NUM_BEEPS );    for( i=0; i< NUM_BEEPS; ++i )    {        err = DoTest( 0 );        if( err != paNoError )            goto error;    }    printf("PortAudio Test: Testing stream playback with priming.\n");    printf("PortAudio Test: you should see BEEP around the same time you hear it.\n");    for( i=0; i< NUM_BEEPS; ++i )    {        err = DoTest( paPrimeOutputBuffersUsingStreamCallback );        if( err != paNoError )            goto error;    }    printf("Test finished.\n");    Pa_Terminate();    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;}