comparison src/portaudio_20140130/examples/paex_ocean_shore.c @ 124:e3d5853d5918

Current stable PortAudio source

+/** @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: paex_ocean_shore.c 1816 2012-02-22 12:20:26Z robiwan $
+ *
+ * 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(1.0 - 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 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;
+}