mirror of
https://github.com/cookiengineer/audacity
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194 lines
6.7 KiB
C
194 lines
6.7 KiB
C
/** @file
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@ingroup test_src
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@brief Hear the latency caused by big buffers.
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Play a sine wave and change frequency based on letter input.
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@author Phil Burk <philburk@softsynth.com>, and Darren Gibbs
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*/
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/*
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* $Id: patest_latency.c 1368 2008-03-01 00:38:27Z rossb $
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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.portaudio.com
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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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* 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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* The text above constitutes the entire PortAudio license; however,
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* the PortAudio community also makes the following non-binding requests:
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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. It is also
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* requested that these non-binding requests be included along with the
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* license above.
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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 OUTPUT_DEVICE (Pa_GetDefaultOutputDevice())
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#define SAMPLE_RATE (44100)
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#define FRAMES_PER_BUFFER (64)
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#define MIN_FREQ (100.0f)
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#define CalcPhaseIncrement(freq) ((freq)/SAMPLE_RATE)
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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 TABLE_SIZE (400)
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typedef struct
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{
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float sine[TABLE_SIZE + 1]; /* add one for guard point for interpolation */
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float phase_increment;
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float left_phase;
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float right_phase;
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}
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paTestData;
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float LookupSine( paTestData *data, float phase );
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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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{
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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, 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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int i;
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(void) inputBuffer; /* Prevent unused variable warning. */
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for( i=0; i<framesPerBuffer; i++ )
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{
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*out++ = LookupSine(data, data->left_phase); /* left */
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*out++ = LookupSine(data, data->right_phase); /* right */
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data->left_phase += data->phase_increment;
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if( data->left_phase >= 1.0f ) data->left_phase -= 1.0f;
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data->right_phase += (data->phase_increment * 1.5f); /* fifth above */
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if( data->right_phase >= 1.0f ) data->right_phase -= 1.0f;
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}
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return 0;
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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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PaStream *stream;
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PaStreamParameters outputParameters;
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PaError err;
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paTestData data;
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int i;
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int done = 0;
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printf("PortAudio Test: enter letter then hit ENTER.\n" );
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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] = 0.90f * (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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data.left_phase = data.right_phase = 0.0;
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data.phase_increment = CalcPhaseIncrement(MIN_FREQ);
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err = Pa_Initialize();
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if( err != paNoError ) goto error;
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printf("PortAudio Test: output device = %d\n", OUTPUT_DEVICE );
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outputParameters.device = OUTPUT_DEVICE;
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if (outputParameters.device == paNoDevice) {
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fprintf(stderr,"Error: No default output device.\n");
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goto error;
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}
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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.suggestedLatency = Pa_GetDeviceInfo( outputParameters.device )->defaultLowOutputLatency;
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outputParameters.hostApiSpecificStreamInfo = NULL;
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printf("Requested output latency = %.4f seconds.\n", outputParameters.suggestedLatency );
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printf("%d frames per buffer.\n.", FRAMES_PER_BUFFER );
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err = Pa_OpenStream(
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&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|paDitherOff, /* we won't output out of range samples so don't bother clipping them */
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patestCallback,
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&data );
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if( err != paNoError ) goto error;
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err = Pa_StartStream( stream );
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if( err != paNoError ) goto error;
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printf("Play ASCII keyboard. Hit 'q' to stop. (Use RETURN key on Mac)\n");
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fflush(stdout);
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while ( !done )
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{
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float freq;
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int index;
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char c;
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do
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{
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c = getchar();
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}
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while( c < ' '); /* Strip white space and control chars. */
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if( c == 'q' ) done = 1;
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index = c % 26;
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freq = MIN_FREQ + (index * 40.0);
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data.phase_increment = CalcPhaseIncrement(freq);
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}
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printf("Call Pa_StopStream()\n");
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err = Pa_StopStream( stream );
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if( err != paNoError ) 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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