patest_longsine.c

一个开源的sip源代码

/** @file patest_longsine.c
	@ingroup test_src
	@brief Play a sine wave until ENTER hit.
	@author Phil Burk  http://www.softsynth.com
*/
/*
 * $Id: patest_longsine.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"

#define SAMPLE_RATE   (44100)

#ifndef M_PI
#define M_PI  (3.14159265)
#endif

#define TABLE_SIZE   (200)
typedef struct
{
    float sine[TABLE_SIZE];
    int left_phase;
    int 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)
{
    paTestData *data = (paTestData*)userData;
    float *out = (float*)outputBuffer;
    unsigned int i;
    (void) inputBuffer; /* Prevent unused argument warning. */
    for( i=0; i<framesPerBuffer; i++ )
    {
        *out++ = data->sine[data->left_phase];  /* left */
        *out++ = data->sine[data->right_phase];  /* right */
        data->left_phase += 1;
        if( data->left_phase >= TABLE_SIZE ) data->left_phase -= TABLE_SIZE;
        data->right_phase += 3; /* higher pitch so we can distinguish left and right. */
        if( data->right_phase >= TABLE_SIZE ) data->right_phase -= TABLE_SIZE;
    }
    return 0;
}

/*******************************************************************/
int main(void);
int main(void)
{
    PaStreamParameters outputParameters;
    PaStream *stream;
    PaError err;
    paTestData data;
    int i;
    printf("PortAudio Test: output sine wave.\n");

    /* initialise sinusoidal wavetable */
    for( i=0; i<TABLE_SIZE; i++ )
    {
        data.sine[i] = (float) sin( ((double)i/(double)TABLE_SIZE) * M_PI * 2. );
    }
    data.left_phase = data.right_phase = 0;

    err = Pa_Initialize();
    if( err != paNoError ) goto error;

    outputParameters.device = Pa_GetDefaultOutputDevice(); /* default output device */
    outputParameters.channelCount = 2;                     /* stereo output */
    outputParameters.sampleFormat = paFloat32;             /* 32 bit floating point output */
    outputParameters.suggestedLatency = Pa_GetDeviceInfo( outputParameters.device )->defaultLowOutputLatency;
    outputParameters.hostApiSpecificStreamInfo = NULL;

    err = Pa_OpenStream( &stream,
                         NULL,              /* No input. */
                         &outputParameters, /* As above. */
                         SAMPLE_RATE,
                         256,               /* Frames per buffer. */
                         paClipOff,         /* No out of range samples expected. */
                         patestCallback,
                         &data );
    if( err != paNoError ) goto error;

    err = Pa_StartStream( stream );
    if( err != paNoError ) goto error;

    printf("Hit ENTER to stop program.\n");
    getchar();

    err = Pa_CloseStream( stream );
    if( err != paNoError ) goto error;
    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;
}