PortAudio: paex_ocean_shore.c File Reference

PortAudio 2.0

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paex_ocean_shore.c File Reference
Example programs demonstrating PortAudio usage

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. More...

`#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"`

Go to the source code of this file.

## Data Structures
struct | PinkNoise
struct | BiQuad
struct | OceanWave
struct | paTestData

## Macros
#define | PINK_MAX_RANDOM_ROWS (30)
#define | PINK_RANDOM_BITS (24)
#define | PINK_RANDOM_SHIFT ((sizeof(long)*8)-PINK_RANDOM_BITS)
#define | NEW_ROW_SIZE (12 + (8*rand())/RAND_MAX)

## Enumerations
enum | EnvState { State_kAttack, State_kPreDecay, State_kDecay, State_kCnt }

## Functions
void | InitializePinkNoise (PinkNoise *pink, int numRows)
float | GeneratePinkNoise (PinkNoise *pink)
unsigned | GenerateWave (OceanWave *wave, float *output, unsigned noOfFrames)
float | ProcessBiquad (const BiQuad *coeffs, float *memory, float input)
OceanWave * | InitializeWave (double SR, float attackInSeconds, float maxLevel, float positionLeftRight)
int | main (void)

## Detailed Description

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.

            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 Robert Bielik

Definition in file paex_ocean_shore.c.