205 lines
7.1 KiB
C
205 lines
7.1 KiB
C
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/** @file patest_maxsines.c
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@brief How many sine waves can we calculate and play in less than 80% CPU Load.
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@author Ross Bencina <rossb@audiomulch.com>
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@author Phil Burk <philburk@softsynth.com>
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*/
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/*
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* $Id: patest_maxsines.c,v 1.1 2006/06/10 21:30:56 dmazzoni Exp $
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*
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* This program uses the PortAudio Portable Audio Library.
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* For more information see: http://www.audiomulch.com/portaudio/
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* Copyright (c) 1999-2000 Ross Bencina and Phil Burk
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*
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* Permission is hereby granted, free of charge, to any person obtaining
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* a copy of this software and associated documentation files
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* (the "Software"), to deal in the Software without restriction,
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* including without limitation the rights to use, copy, modify, merge,
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* publish, distribute, sublicense, and/or sell copies of the Software,
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* and to permit persons to whom the Software is furnished to do so,
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* subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be
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* included in all copies or substantial portions of the Software.
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*
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* Any person wishing to distribute modifications to the Software is
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* requested to send the modifications to the original developer so that
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* they can be incorporated into the canonical version.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
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* ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
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* CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
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* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*
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*/
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#include <stdio.h>
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#include <math.h>
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#include "portaudio.h"
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#define MAX_SINES (500)
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#define MAX_USAGE (0.8)
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#define SAMPLE_RATE (44100)
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#define FREQ_TO_PHASE_INC(freq) (freq/(float)SAMPLE_RATE)
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#define MIN_PHASE_INC FREQ_TO_PHASE_INC(200.0f)
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#define MAX_PHASE_INC (MIN_PHASE_INC * (1 << 5))
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#define FRAMES_PER_BUFFER (512)
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#ifndef M_PI
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#define M_PI (3.14159265)
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#endif
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#define TWOPI (M_PI * 2.0)
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#define TABLE_SIZE (512)
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typedef struct paTestData
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{
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int numSines;
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float sine[TABLE_SIZE + 1]; /* add one for guard point for interpolation */
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float phases[MAX_SINES];
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}
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paTestData;
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/* Convert phase between and 1.0 to sine value
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* using linear interpolation.
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*/
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float LookupSine( paTestData *data, float phase );
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float LookupSine( paTestData *data, float phase )
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{
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float fIndex = phase*TABLE_SIZE;
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int index = (int) fIndex;
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float fract = fIndex - index;
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float lo = data->sine[index];
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float hi = data->sine[index+1];
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float val = lo + fract*(hi-lo);
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return val;
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}
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/* This routine will be called by the PortAudio engine when audio is needed.
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** It may called at interrupt level on some machines so don't do anything
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** that could mess up the system like calling malloc() or free().
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*/
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static int patestCallback(const void* inputBuffer,
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void* outputBuffer,
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unsigned long framesPerBuffer,
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const PaStreamCallbackTimeInfo* timeInfo,
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PaStreamCallbackFlags statusFlags,
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void* userData )
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{
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paTestData *data = (paTestData*)userData;
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float *out = (float*)outputBuffer;
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float outSample;
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float scaler;
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int numForScale;
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unsigned long i;
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int j;
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int finished = 0;
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(void) inputBuffer; /* Prevent unused argument warning. */
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/* Determine amplitude scaling factor */
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numForScale = data->numSines;
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if( numForScale < 8 ) numForScale = 8; /* prevent pops at beginning */
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scaler = 1.0f / numForScale;
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for( i=0; i<framesPerBuffer; i++ )
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{
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float output = 0.0;
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float phaseInc = MIN_PHASE_INC;
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float phase;
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for( j=0; j<data->numSines; j++ )
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{
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/* Advance phase of next oscillator. */
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phase = data->phases[j];
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phase += phaseInc;
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if( phase >= 1.0 ) phase -= 1.0;
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output += LookupSine(data, phase);
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data->phases[j] = phase;
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phaseInc *= 1.02f;
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if( phaseInc > MAX_PHASE_INC ) phaseInc = MIN_PHASE_INC;
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}
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outSample = (float) (output * scaler);
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*out++ = outSample; /* Left */
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*out++ = outSample; /* Right */
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}
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return finished;
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}
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/*******************************************************************/
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int main(void);
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int main(void)
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{
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int i;
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PaStream* stream;
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PaStreamParameters outputParameters;
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PaError err;
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paTestData data = {0};
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double load;
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printf("PortAudio Test: output sine wave. SR = %d, BufSize = %d\n", SAMPLE_RATE, FRAMES_PER_BUFFER);
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/* initialise sinusoidal wavetable */
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for( i=0; i<TABLE_SIZE; i++ )
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{
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data.sine[i] = (float) sin( ((double)i/(double)TABLE_SIZE) * M_PI * 2. );
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}
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data.sine[TABLE_SIZE] = data.sine[0]; /* set guard point */
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err = Pa_Initialize();
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if( err != paNoError )
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goto error;
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outputParameters.device = Pa_GetDefaultOutputDevice(); /* Default output device. */
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outputParameters.channelCount = 2; /* Stereo output. */
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outputParameters.sampleFormat = paFloat32; /* 32 bit floating point output. */
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outputParameters.hostApiSpecificStreamInfo = NULL;
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outputParameters.suggestedLatency = Pa_GetDeviceInfo(outputParameters.device)
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->defaultHighOutputLatency;
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err = Pa_OpenStream(&stream,
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NULL, /* no input */
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&outputParameters,
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SAMPLE_RATE,
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FRAMES_PER_BUFFER,
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paClipOff, /* No out of range samples should occur. */
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patestCallback,
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&data);
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if( err != paNoError )
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goto error;
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err = Pa_StartStream( stream );
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if( err != paNoError )
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goto error;
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/* Play an increasing number of sine waves until we hit MAX_USAGE */
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do {
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data.numSines++;
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Pa_Sleep(200);
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load = Pa_GetStreamCpuLoad(stream);
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printf("numSines = %d, CPU load = %f\n", data.numSines, load );
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fflush(stdout);
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} while((load < MAX_USAGE) && (data.numSines < MAX_SINES));
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Pa_Sleep(2000); /* Stay for 2 seconds around 80% CPU. */
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err = Pa_StopStream( stream );
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if( err != paNoError )
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goto error;
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err = Pa_CloseStream( stream );
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if( err != paNoError )
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goto error;
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Pa_Terminate();
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printf("Test finished.\n");
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return err;
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error:
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Pa_Terminate();
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fprintf( stderr, "An error occured while using the portaudio stream\n" );
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fprintf( stderr, "Error number: %d\n", err );
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fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( err ) );
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return err;
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}
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