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prosperon/source/portaudio/examples/paex_ocean_shore.c

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/** @file paex_ocean_shore.c
@ingroup examples_src
@brief Generate Pink Noise using Gardner method, and make "waves". Provides an example of how to
post stuff to/from the audio callback using lock-free FIFOs implemented by the PA ringbuffer.
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
Robert Bielik
*/
/*
* $Id$
*
* 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 <stdlib.h>
#include <string.h>
#include <math.h>
#include <time.h>
#include "portaudio.h"
#include "pa_ringbuffer.h"
#include "pa_util.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;
typedef struct
{
float bq_b0;
float bq_b1;
float bq_b2;
float bq_a1;
float bq_a2;
} BiQuad;
typedef enum
{
State_kAttack,
State_kPreDecay,
State_kDecay,
State_kCnt,
} EnvState;
typedef struct
{
PinkNoise wave_left;
PinkNoise wave_right;
BiQuad wave_bq_coeffs;
float wave_bq_left[2];
float wave_bq_right[2];
EnvState wave_envelope_state;
float wave_envelope_level;
float wave_envelope_max_level;
float wave_pan_left;
float wave_pan_right;
float wave_attack_incr;
float wave_decay_incr;
} OceanWave;
/* Prototypes */
static unsigned long GenerateRandomNumber( void );
void InitializePinkNoise( PinkNoise *pink, int numRows );
float GeneratePinkNoise( PinkNoise *pink );
unsigned GenerateWave( OceanWave* wave, float* output, unsigned noOfFrames);
/************************************************************/
/* 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;
}
/* 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;
return output;
}
float ProcessBiquad(const BiQuad* coeffs, float* memory, float input)
{
float w = input - coeffs->bq_a1 * memory[0] - coeffs->bq_a2 * memory[1];
float out = coeffs->bq_b1 * memory[0] + coeffs->bq_b2 * memory[1] + coeffs->bq_b0 * w;
memory[1] = memory[0];
memory[0] = w;
return out;
}
static const float one_over_2Q_LP = 0.3f;
static const float one_over_2Q_HP = 1.0f;
unsigned GenerateWave( OceanWave* wave, float* output, unsigned noOfFrames )
{
unsigned retval=0,i;
float targetLevel, levelIncr, currentLevel;
switch (wave->wave_envelope_state)
{
case State_kAttack:
targetLevel = noOfFrames * wave->wave_attack_incr + wave->wave_envelope_level;
if (targetLevel >= wave->wave_envelope_max_level)
{
/* Go to decay state */
wave->wave_envelope_state = State_kPreDecay;
targetLevel = wave->wave_envelope_max_level;
}
/* Calculate lowpass biquad coeffs
alpha = sin(w0)/(2*Q)
b0 = (1 - cos(w0))/2
b1 = 1 - cos(w0)
b2 = (1 - cos(w0))/2
a0 = 1 + alpha
a1 = -2*cos(w0)
a2 = 1 - alpha
w0 = [0 - pi[
*/
{
const float w0 = 3.141592654f * targetLevel / wave->wave_envelope_max_level;
const float alpha = sinf(w0) * one_over_2Q_LP;
const float cosw0 = cosf(w0);
const float a0_fact = 1.0f / (1.0f + alpha);
wave->wave_bq_coeffs.bq_b1 = (1.0f - cosw0) * a0_fact;
wave->wave_bq_coeffs.bq_b0 = wave->wave_bq_coeffs.bq_b1 * 0.5f;
wave->wave_bq_coeffs.bq_b2 = wave->wave_bq_coeffs.bq_b0;
wave->wave_bq_coeffs.bq_a2 = (1.0f - alpha) * a0_fact;
wave->wave_bq_coeffs.bq_a1 = -2.0f * cosw0 * a0_fact;
}
break;
case State_kPreDecay:
/* Reset biquad state */
memset(wave->wave_bq_left, 0, 2 * sizeof(float));
memset(wave->wave_bq_right, 0, 2 * sizeof(float));
wave->wave_envelope_state = State_kDecay;
/* Deliberate fall-through */
case State_kDecay:
targetLevel = noOfFrames * wave->wave_decay_incr + wave->wave_envelope_level;
if (targetLevel < 0.001f)
{
/* < -60 dB, we're done */
wave->wave_envelope_state = 3;
retval = 1;
}
/* Calculate highpass biquad coeffs
alpha = sin(w0)/(2*Q)
b0 = (1 + cos(w0))/2
b1 = -(1 + cos(w0))
b2 = (1 + cos(w0))/2
a0 = 1 + alpha
a1 = -2*cos(w0)
a2 = 1 - alpha
w0 = [0 - pi/2[
*/
{
const float v = targetLevel / wave->wave_envelope_max_level;
const float w0 = 1.5707963f * (1.0f - (v*v));
const float alpha = sinf(w0) * one_over_2Q_HP;
const float cosw0 = cosf(w0);
const float a0_fact = 1.0f / (1.0f + alpha);
wave->wave_bq_coeffs.bq_b1 = (float)(- (1 + cosw0) * a0_fact);
wave->wave_bq_coeffs.bq_b0 = -wave->wave_bq_coeffs.bq_b1 * 0.5f;
wave->wave_bq_coeffs.bq_b2 = wave->wave_bq_coeffs.bq_b0;
wave->wave_bq_coeffs.bq_a2 = (float)((1.0 - alpha) * a0_fact);
wave->wave_bq_coeffs.bq_a1 = (float)(-2.0 * cosw0 * a0_fact);
}
break;
default:
break;
}
currentLevel = wave->wave_envelope_level;
wave->wave_envelope_level = targetLevel;
levelIncr = (targetLevel - currentLevel) / noOfFrames;
for (i = 0; i < noOfFrames; ++i, currentLevel += levelIncr)
{
(*output++) += ProcessBiquad(&wave->wave_bq_coeffs, wave->wave_bq_left, (GeneratePinkNoise(&wave->wave_left))) * currentLevel * wave->wave_pan_left;
(*output++) += ProcessBiquad(&wave->wave_bq_coeffs, wave->wave_bq_right, (GeneratePinkNoise(&wave->wave_right))) * currentLevel * wave->wave_pan_right;
}
return retval;
}
/*******************************************************************/
/* Context for callback routine. */
typedef struct
{
OceanWave* waves[16]; /* Maximum 16 waves */
unsigned noOfActiveWaves;
/* Ring buffer (FIFO) for "communicating" towards audio callback */
PaUtilRingBuffer rBufToRT;
void* rBufToRTData;
/* Ring buffer (FIFO) for "communicating" from audio callback */
PaUtilRingBuffer rBufFromRT;
void* rBufFromRTData;
}
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 i;
paTestData *data = (paTestData*)userData;
float *out = (float*)outputBuffer;
(void) inputBuffer; /* Prevent "unused variable" warnings. */
/* Reset output data first */
memset(out, 0, framesPerBuffer * 2 * sizeof(float));
for (i = 0; i < 16; ++i)
{
/* Consume the input queue */
if (data->waves[i] == 0 && PaUtil_GetRingBufferReadAvailable(&data->rBufToRT))
{
OceanWave* ptr = 0;
PaUtil_ReadRingBuffer(&data->rBufToRT, &ptr, 1);
data->waves[i] = ptr;
}
if (data->waves[i] != 0)
{
if (GenerateWave(data->waves[i], out, framesPerBuffer))
{
/* If wave is "done", post it back to the main thread for deletion */
PaUtil_WriteRingBuffer(&data->rBufFromRT, &data->waves[i], 1);
data->waves[i] = 0;
}
}
}
return paContinue;
}
#define NEW_ROW_SIZE (12 + (8*rand())/RAND_MAX)
OceanWave* InitializeWave(double SR, float attackInSeconds, float maxLevel, float positionLeftRight)
{
OceanWave* wave = NULL;
static unsigned lastNoOfRows = 12;
unsigned newNoOfRows;
wave = (OceanWave*)PaUtil_AllocateMemory(sizeof(OceanWave));
if (wave != NULL)
{
InitializePinkNoise(&wave->wave_left, lastNoOfRows);
while ((newNoOfRows = NEW_ROW_SIZE) == lastNoOfRows);
InitializePinkNoise(&wave->wave_right, newNoOfRows);
lastNoOfRows = newNoOfRows;
wave->wave_envelope_state = State_kAttack;
wave->wave_envelope_level = 0.f;
wave->wave_envelope_max_level = maxLevel;
wave->wave_attack_incr = wave->wave_envelope_max_level / (attackInSeconds * (float)SR);
wave->wave_decay_incr = - wave->wave_envelope_max_level / (attackInSeconds * 4 * (float)SR);
wave->wave_pan_left = sqrtf(1.0f - positionLeftRight);
wave->wave_pan_right = sqrtf(positionLeftRight);
}
return wave;
}
static float GenerateFloatRandom(float minValue, float maxValue)
{
return minValue + ((maxValue - minValue) * rand()) / RAND_MAX;
}
/*******************************************************************/
int main(void);
int main(void)
{
PaStream* stream;
PaError err;
paTestData data = {0};
PaStreamParameters outputParameters;
double tstamp;
double tstart;
double tdelta = 0;
static const double SR = 44100.0;
static const int FPB = 128; /* Frames per buffer: 2.9 ms buffers. */
/* Initialize communication buffers (queues) */
data.rBufToRTData = PaUtil_AllocateMemory(sizeof(OceanWave*) * 256);
if (data.rBufToRTData == NULL)
{
return 1;
}
PaUtil_InitializeRingBuffer(&data.rBufToRT, sizeof(OceanWave*), 256, data.rBufToRTData);
data.rBufFromRTData = PaUtil_AllocateMemory(sizeof(OceanWave*) * 256);
if (data.rBufFromRTData == NULL)
{
return 1;
}
PaUtil_InitializeRingBuffer(&data.rBufFromRT, sizeof(OceanWave*), 256, data.rBufFromRTData);
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. */
paDitherOff, /* Clip but don't dither */
patestCallback,
&data);
if( err != paNoError ) goto error;
err = Pa_StartStream( stream );
if( err != paNoError ) goto error;
printf("Stereo \"ocean waves\" for one minute...\n");
tstart = PaUtil_GetTime();
tstamp = tstart;
srand( (unsigned)time(NULL) );
while( ( err = Pa_IsStreamActive( stream ) ) == 1 )
{
const double tcurrent = PaUtil_GetTime();
/* Delete "waves" that the callback is finished with */
while (PaUtil_GetRingBufferReadAvailable(&data.rBufFromRT) > 0)
{
OceanWave* ptr = 0;
PaUtil_ReadRingBuffer(&data.rBufFromRT, &ptr, 1);
if (ptr != 0)
{
printf("Wave is deleted...\n");
PaUtil_FreeMemory(ptr);
--data.noOfActiveWaves;
}
}
if (tcurrent - tstart < 60.0) /* Only start new "waves" during one minute */
{
if (tcurrent >= tstamp)
{
double tdelta = GenerateFloatRandom(1.0f, 4.0f);
tstamp += tdelta;
if (data.noOfActiveWaves<16)
{
const float attackTime = GenerateFloatRandom(2.0f, 6.0f);
const float level = GenerateFloatRandom(0.1f, 1.0f);
const float pos = GenerateFloatRandom(0.0f, 1.0f);
OceanWave* p = InitializeWave(SR, attackTime, level, pos);
if (p != NULL)
{
/* Post wave to audio callback */
PaUtil_WriteRingBuffer(&data.rBufToRT, &p, 1);
++data.noOfActiveWaves;
printf("Starting wave at level = %.2f, attack = %.2lf, pos = %.2lf\n", level, attackTime, pos);
}
}
}
}
else
{
if (data.noOfActiveWaves == 0)
{
printf("All waves finished!\n");
break;
}
}
Pa_Sleep(100);
}
if( err < 0 ) goto error;
err = Pa_CloseStream( stream );
if( err != paNoError ) goto error;
if (data.rBufToRTData)
{
PaUtil_FreeMemory(data.rBufToRTData);
}
if (data.rBufFromRTData)
{
PaUtil_FreeMemory(data.rBufFromRTData);
}
Pa_Sleep(1000);
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;
}
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