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-rw-r--r--pd/portaudio_v18/pa_tests/patest_pink.c245
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diff --git a/pd/portaudio_v18/pa_tests/patest_pink.c b/pd/portaudio_v18/pa_tests/patest_pink.c
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--- a/pd/portaudio_v18/pa_tests/patest_pink.c
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-/*
- * $Id: patest_pink.c,v 1.1.1.1 2002/01/22 00:52:36 phil Exp $
- patest_pink.c
- Generate Pink Noise using Gardner method.
- Optimization suggested by James McCartney uses a tree
- to select which random value to replace.
- x x x x x x x x x x x x x x x x
- x x x x x x x x
- x x x x
- x x
- x
- Tree is generated by counting trailing zeros in an increasing index.
- When the index is zero, no random number is selected.
- *
- * 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 <math.h>
-#include "portaudio.h"
-#define PINK_MAX_RANDOM_ROWS (30)
-#define PINK_RANDOM_BITS (24)
-#define PINK_RANDOM_SHIFT ((sizeof(long)*8)-PINK_RANDOM_BITS)
-typedef struct
-{
- long pink_Rows[PINK_MAX_RANDOM_ROWS];
- long pink_RunningSum; /* Used to optimize summing of generators. */
- int pink_Index; /* Incremented each sample. */
- int pink_IndexMask; /* Index wrapped by ANDing with this mask. */
- float pink_Scalar; /* Used to scale within range of -1.0 to +1.0 */
-}
-PinkNoise;
-/* Prototypes */
-static unsigned long GenerateRandomNumber( void );
-void InitializePinkNoise( PinkNoise *pink, int numRows );
-float GeneratePinkNoise( PinkNoise *pink );
-/************************************************************/
-/* Calculate pseudo-random 32 bit number based on linear congruential method. */
-static unsigned long GenerateRandomNumber( void )
-{
- /* Change this seed for different random sequences. */
- static unsigned long randSeed = 22222;
- randSeed = (randSeed * 196314165) + 907633515;
- return randSeed;
-}
-/************************************************************/
-/* Setup PinkNoise structure for N rows of generators. */
-void InitializePinkNoise( PinkNoise *pink, int numRows )
-{
- int i;
- long pmax;
- pink->pink_Index = 0;
- pink->pink_IndexMask = (1<<numRows) - 1;
- /* Calculate maximum possible signed random value. Extra 1 for white noise always added. */
- pmax = (numRows + 1) * (1<<(PINK_RANDOM_BITS-1));
- pink->pink_Scalar = 1.0f / pmax;
- /* Initialize rows. */
- for( i=0; i<numRows; i++ ) pink->pink_Rows[i] = 0;
- pink->pink_RunningSum = 0;
-}
-#define PINK_MEASURE
-#ifdef PINK_MEASURE
-float pinkMax = -999.0;
-float pinkMin = 999.0;
-#endif
-/* Generate Pink noise values between -1.0 and +1.0 */
-float GeneratePinkNoise( PinkNoise *pink )
-{
- long newRandom;
- long sum;
- float output;
- /* Increment and mask index. */
- pink->pink_Index = (pink->pink_Index + 1) & pink->pink_IndexMask;
- /* If index is zero, don't update any random values. */
- if( pink->pink_Index != 0 )
- {
- /* Determine how many trailing zeros in PinkIndex. */
- /* This algorithm will hang if n==0 so test first. */
- int numZeros = 0;
- int n = pink->pink_Index;
- while( (n & 1) == 0 )
- {
- n = n >> 1;
- numZeros++;
- }
- /* Replace the indexed ROWS random value.
- * Subtract and add back to RunningSum instead of adding all the random
- * values together. Only one changes each time.
- */
- pink->pink_RunningSum -= pink->pink_Rows[numZeros];
- newRandom = ((long)GenerateRandomNumber()) >> PINK_RANDOM_SHIFT;
- pink->pink_RunningSum += newRandom;
- pink->pink_Rows[numZeros] = newRandom;
- }
-
- /* Add extra white noise value. */
- newRandom = ((long)GenerateRandomNumber()) >> PINK_RANDOM_SHIFT;
- sum = pink->pink_RunningSum + newRandom;
- /* Scale to range of -1.0 to 0.9999. */
- output = pink->pink_Scalar * sum;
-#ifdef PINK_MEASURE
- /* Check Min/Max */
- if( output > pinkMax ) pinkMax = output;
- else if( output < pinkMin ) pinkMin = output;
-#endif
- return output;
-}
-/*******************************************************************/
-#define PINK_TEST
-#ifdef PINK_TEST
-/* Context for callback routine. */
-typedef struct
-{
- PinkNoise leftPink;
- PinkNoise rightPink;
- unsigned int sampsToGo;
-}
-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( void *inputBuffer, void *outputBuffer,
- unsigned long framesPerBuffer,
- PaTimestamp outTime, void *userData )
-{
- int finished;
- int i;
- int numFrames;
- paTestData *data = (paTestData*)userData;
- float *out = (float*)outputBuffer;
- (void) inputBuffer; /* Prevent "unused variable" warnings. */
- (void) outTime;
-
- /* Are we almost at end. */
- if( data->sampsToGo < framesPerBuffer )
- {
- numFrames = data->sampsToGo;
- finished = 1;
- }
- else
- {
- numFrames = framesPerBuffer;
- finished = 0;
- }
- for( i=0; i<numFrames; i++ )
- {
- *out++ = GeneratePinkNoise( &data->leftPink );
- *out++ = GeneratePinkNoise( &data->rightPink );
- }
- data->sampsToGo -= numFrames;
- return finished;
-}
-/*******************************************************************/
-int main(void);
-int main(void)
-{
- PortAudioStream *stream;
- PaError err;
- paTestData data;
- int totalSamps;
- /* Initialize two pink noise signals with different numbers of rows. */
- InitializePinkNoise( &data.leftPink, 12 );
- InitializePinkNoise( &data.rightPink, 16 );
- /* Look at a few values. */
- {
- int i;
- float pink;
- for( i=0; i<20; i++ )
- {
- pink = GeneratePinkNoise( &data.leftPink );
- printf("Pink = %f\n", pink );
- }
- }
- data.sampsToGo = totalSamps = 8*44100; /* Play for a few seconds. */
- err = Pa_Initialize();
- if( err != paNoError ) goto error;
- /* Open a stereo PortAudio stream so we can hear the result. */
- err = Pa_OpenStream(
- &stream,
- paNoDevice,
- 0, /* no input */
- paFloat32, /* 32 bit floating point input */
- NULL,
- Pa_GetDefaultOutputDeviceID(), /* default output device */
- 2, /* stereo output */
- paFloat32, /* 32 bit floating point output */
- NULL,
- 44100.,
- 2048, /* 46 msec buffers */
- 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 */
- patestCallback,
- &data );
- if( err != paNoError ) goto error;
-
- err = Pa_StartStream( stream );
- if( err != paNoError ) goto error;
- printf("Waiting for sound to finish.\n");
- while( Pa_StreamActive( stream ) )
- {
- Pa_Sleep(100); /* SPIN! */
- }
- err = Pa_CloseStream( stream );
- if( err != paNoError ) goto error;
-#ifdef PINK_MEASURE
- printf("Pink min = %f, max = %f\n", pinkMin, pinkMax );
-#endif
- Pa_Terminate();
- return 0;
-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 0;
-}
-#endif /* PINK_TEST */
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