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Diffstat (limited to 'portaudio/examples/paex_pink.c')
| -rw-r--r-- | portaudio/examples/paex_pink.c | 280 |
1 files changed, 0 insertions, 280 deletions
diff --git a/portaudio/examples/paex_pink.c b/portaudio/examples/paex_pink.c deleted file mode 100644 index 519f979..0000000 --- a/portaudio/examples/paex_pink.c +++ /dev/null @@ -1,280 +0,0 @@ -/** @file paex_pink.c - @ingroup examples_src - @brief Generate Pink Noise using Gardner method. - - Optimization suggested by James McCartney uses a tree - to select which random value to replace. -<pre> - 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 -</pre> - 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 -*/ -/* - * $Id$ - * - * 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 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(const void* inputBuffer, - void* outputBuffer, - unsigned long framesPerBuffer, - const PaStreamCallbackTimeInfo* timeInfo, - PaStreamCallbackFlags statusFlags, - void* userData) -{ - int finished; - int i; - int numFrames; - paTestData *data = (paTestData*)userData; - float *out = (float*)outputBuffer; - (void) inputBuffer; /* Prevent "unused variable" warnings. */ - - /* 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) -{ - PaStream* stream; - PaError err; - paTestData data; - PaStreamParameters outputParameters; - int totalSamps; - static const double SR = 44100.0; - static const int FPB = 2048; /* Frames per buffer: 46 ms buffers. */ - - /* 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 = (int)(60.0 * SR); /* Play a whole minute. */ - err = Pa_Initialize(); - if( err != paNoError ) goto error; - - /* Open a stereo PortAudio stream so we can hear the result. */ - outputParameters.device = Pa_GetDefaultOutputDevice(); /* Take the default output device. */ - if (outputParameters.device == paNoDevice) { - fprintf(stderr,"Error: No default output device.\n"); - goto error; - } - outputParameters.channelCount = 2; /* Stereo output, most likely supported. */ - outputParameters.hostApiSpecificStreamInfo = NULL; - outputParameters.sampleFormat = paFloat32; /* 32 bit floating point output. */ - outputParameters.suggestedLatency = - Pa_GetDeviceInfo(outputParameters.device)->defaultLowOutputLatency; - err = Pa_OpenStream(&stream, - NULL, /* No input. */ - &outputParameters, - SR, /* Sample rate. */ - FPB, /* Frames per buffer. */ - 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("Stereo pink noise for one minute...\n"); - - while( ( err = Pa_IsStreamActive( stream ) ) == 1 ) Pa_Sleep(100); - if( err < 0 ) goto error; - - 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 occurred 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 */ |