source: portaudio/branches/V18.1/pa_tests/patest_buffer.c @ 90

/*
 * $Id$
 * patest_buffer.c
 * Test opening streams with different buffer sizes.
 *
 * Author: Phil Burk  http://www.softsynth.com
 *
 * 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.
 *
 * 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.
 *
 * 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.
 *
 */
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include "portaudio.h"
#define NUM_SECONDS   (1)
#define SAMPLE_RATE   (44100)
#ifndef M_PI
#define M_PI  (3.14159265)
#endif
#define TABLE_SIZE   (200)

#define BUFFER_TABLE  9
long buffer_table[] = {200,256,500,512,600, 723, 1000, 1024, 2345};

typedef struct
{
    short sine[TABLE_SIZE];
    int left_phase;
    int right_phase;
    unsigned int sampsToGo;
}
paTestData;
PaError TestOnce( int buffersize );

static int patest1Callback( void *inputBuffer, void *outputBuffer,
                            unsigned long framesPerBuffer,
                            PaTimestamp outTime, void *userData );
/* 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 patest1Callback( void *inputBuffer, void *outputBuffer,
                            unsigned long framesPerBuffer,
                            PaTimestamp outTime, void *userData )
{
    paTestData *data = (paTestData*)userData;
    short *out = (short*)outputBuffer;
    unsigned int i;
    int finished = 0;
    (void) inputBuffer; /* Prevent "unused variable" warnings. */
    (void) outTime;

    if( data->sampsToGo < framesPerBuffer )
    {
        /* final buffer... */

        for( i=0; i<data->sampsToGo; 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;
        }
        /* zero remainder of final buffer */
        for( ; i<framesPerBuffer; i++ )
        {
            *out++ = 0; /* left */
            *out++ = 0; /* right */
        }

        finished = 1;
    }
    else
    {
        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;
        }
        data->sampsToGo -= framesPerBuffer;
    }
    return finished;
}
/*******************************************************************/
int main(void);
int main(void)
{
    int i;
    PaError err;
    printf("Test opening streams with different buffer sizes\n\n");

    for (i = 0 ; i < BUFFER_TABLE; i++)
    {
        printf("Buffer size %d\n", buffer_table[i]);
        err = TestOnce(buffer_table[i]);
        if( err < 0 ) return 0;

    }
}


PaError TestOnce( int buffersize )
{
    PortAudioStream *stream;
    PaError err;
    paTestData data;
    int i;
    int totalSamps;
    /* initialise sinusoidal wavetable */
    for( i=0; i<TABLE_SIZE; i++ )
    {
        data.sine[i] = (short) (32767.0 * sin( ((double)i/(double)TABLE_SIZE) * M_PI * 2. ));
    }
    data.left_phase = data.right_phase = 0;
    data.sampsToGo = totalSamps =  NUM_SECONDS * SAMPLE_RATE; /* Play for a few seconds. */
    err = Pa_Initialize();
    if( err != paNoError ) goto error;
    err = Pa_OpenStream(
              &stream,
              paNoDevice,/* default input device */
              0,              /* no input */
              paInt16,  /* sample format */
              NULL,
              Pa_GetDefaultOutputDeviceID(), /* default output device */
              2,              /* stereo output */
              paInt16,        /* sample format */
              NULL,
              SAMPLE_RATE,
              buffersize,           /* frames per buffer */
              0,              /* number of buffers, if zero then use default minimum */
              paClipOff,      /* we won't output out of range samples so don't bother clipping them */
              patest1Callback,
              &data );
    if( err != paNoError ) goto error;

    err = Pa_StartStream( stream );
    if( err != paNoError ) goto error;
    printf("Waiting for sound to finish.\n");
    Pa_Sleep(1000);
    err = Pa_CloseStream( stream );
    if( err != paNoError ) goto error;
    Pa_Terminate();
    return paNoError;
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;
}