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Add support for pink noise.

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This commit is contained in:
David Reid
2020-02-24 20:22:14 +10:00
parent b1c4cfe5cc
commit cf3fd4876f
2 changed files with 148 additions and 16 deletions
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miniaudio.h
+133 -1
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@@ -5162,6 +5162,7 @@ ma_result ma_waveform_set_frequency(ma_waveform* pWaveform, double frequency);
ma_result ma_waveform_set_sample_rate(ma_waveform* pWaveform, ma_uint32 sampleRate);
typedef struct
{
ma_int32 state;
@@ -5170,6 +5171,7 @@ typedef struct
typedef enum
{
ma_noise_type_white,
ma_noise_type_pink
} ma_noise_type;
typedef struct
@@ -5188,6 +5190,15 @@ typedef struct
{
ma_noise_config config;
ma_lcg lcg;
union
{
struct
{
double bin[MA_MAX_CHANNELS][16];
double accumulation[MA_MAX_CHANNELS];
ma_uint32 counter[MA_MAX_CHANNELS];
} pink;
} state;
} ma_noise;
ma_result ma_noise_init(const ma_noise_config* pConfig, ma_noise* pNoise);
@@ -40661,6 +40672,14 @@ ma_result ma_noise_init(const ma_noise_config* pConfig, ma_noise* pNoise)
pNoise->config = *pConfig;
ma_lcg_seed(&pNoise->lcg, pConfig->seed);
if (pNoise->config.type == ma_noise_type_pink) {
ma_uint32 iChannel;
for (iChannel = 0; iChannel < pConfig->channels; iChannel += 1) {
pNoise->state.pink.accumulation[iChannel] = 0;
pNoise->state.pink.counter[iChannel] = 1;
}
}
return MA_SUCCESS;
}
@@ -40677,7 +40696,7 @@ static MA_INLINE ma_int16 ma_noise_s16_white(ma_noise* pNoise)
static MA_INLINE ma_uint64 ma_noise_read_pcm_frames__white(ma_noise* pNoise, void* pFramesOut, ma_uint64 frameCount)
{
ma_uint64 iFrame;
ma_uint64 iChannel;
ma_uint32 iChannel;
if (pNoise->config.format == ma_format_f32) {
float* pFramesOutF32 = (float*)pFramesOut;
@@ -40735,6 +40754,115 @@ static MA_INLINE ma_uint64 ma_noise_read_pcm_frames__white(ma_noise* pNoise, voi
return frameCount;
}
/*
TODO: Optimize this:
x86/64: TZCNT
*/
static MA_INLINE unsigned int ma_tzcnt32(unsigned int x)
{
unsigned int i;
i = 0;
while (((x >> i) & 0x1) == 0 && i < (sizeof(unsigned long) * 8)) {
i += 1;
}
return i;
}
/*
Pink noise generation based on Tonic (public domain) with modifications. https://github.com/TonicAudio/Tonic/blob/master/src/Tonic/Noise.h
This is basically _the_ reference for pink noise from what I've found: http://www.firstpr.com.au/dsp/pink-noise/
*/
static MA_INLINE float ma_noise_f32_pink(ma_noise* pNoise, ma_uint32 iChannel)
{
double result;
double binPrev;
double binNext;
unsigned int ibin;
ibin = ma_tzcnt32(pNoise->state.pink.counter[iChannel]) & (ma_countof(pNoise->state.pink.bin[0]) - 1);
binPrev = pNoise->state.pink.bin[iChannel][ibin];
binNext = ma_lcg_rand_f64(&pNoise->lcg);
pNoise->state.pink.bin[iChannel][ibin] = binNext;
pNoise->state.pink.accumulation[iChannel] += (binNext - binPrev);
pNoise->state.pink.counter[iChannel] += 1;
result = (ma_lcg_rand_f64(&pNoise->lcg) + pNoise->state.pink.accumulation[iChannel]) / 10;
return (float)(result * pNoise->config.amplitude);
}
static MA_INLINE ma_int16 ma_noise_s16_pink(ma_noise* pNoise, ma_uint32 iChannel)
{
return ma_pcm_sample_f32_to_s16(ma_noise_f32_pink(pNoise, iChannel));
}
static MA_INLINE ma_uint64 ma_noise_read_pcm_frames__pink(ma_noise* pNoise, void* pFramesOut, ma_uint64 frameCount)
{
ma_uint64 iFrame;
ma_uint32 iChannel;
if (pNoise->config.format == ma_format_f32) {
float* pFramesOutF32 = (float*)pFramesOut;
if (pNoise->config.duplicateChannels) {
for (iFrame = 0; iFrame < frameCount; iFrame += 1) {
float s = ma_noise_f32_pink(pNoise, 0);
for (iChannel = 0; iChannel < pNoise->config.channels; iChannel += 1) {
pFramesOutF32[iFrame*pNoise->config.channels + iChannel] = s;
}
}
} else {
for (iFrame = 0; iFrame < frameCount; iFrame += 1) {
for (iChannel = 0; iChannel < pNoise->config.channels; iChannel += 1) {
pFramesOutF32[iFrame*pNoise->config.channels + iChannel] = ma_noise_f32_pink(pNoise, iChannel);
}
}
}
} else if (pNoise->config.format == ma_format_s16) {
ma_int16* pFramesOutS16 = (ma_int16*)pFramesOut;
if (pNoise->config.duplicateChannels) {
for (iFrame = 0; iFrame < frameCount; iFrame += 1) {
ma_int16 s = ma_noise_s16_pink(pNoise, 0);
for (iChannel = 0; iChannel < pNoise->config.channels; iChannel += 1) {
pFramesOutS16[iFrame*pNoise->config.channels + iChannel] = s;
}
}
} else {
for (iFrame = 0; iFrame < frameCount; iFrame += 1) {
for (iChannel = 0; iChannel < pNoise->config.channels; iChannel += 1) {
pFramesOutS16[iFrame*pNoise->config.channels + iChannel] = ma_noise_s16_pink(pNoise, iChannel);
}
}
}
} else {
ma_uint32 bps = ma_get_bytes_per_sample(pNoise->config.format);
ma_uint32 bpf = bps * pNoise->config.channels;
if (pNoise->config.duplicateChannels) {
for (iFrame = 0; iFrame < frameCount; iFrame += 1) {
float s = ma_noise_f32_pink(pNoise, 0);
for (iChannel = 0; iChannel < pNoise->config.channels; iChannel += 1) {
ma_pcm_convert(ma_offset_ptr(pFramesOut, iFrame*bpf + iChannel*bps), pNoise->config.format, &s, ma_format_f32, 1, ma_dither_mode_none);
}
}
} else {
for (iFrame = 0; iFrame < frameCount; iFrame += 1) {
for (iChannel = 0; iChannel < pNoise->config.channels; iChannel += 1) {
float s = ma_noise_f32_pink(pNoise, iChannel);
ma_pcm_convert(ma_offset_ptr(pFramesOut, iFrame*bpf + iChannel*bps), pNoise->config.format, &s, ma_format_f32, 1, ma_dither_mode_none);
}
}
}
}
return frameCount;
}
ma_uint64 ma_noise_read_pcm_frames(ma_noise* pNoise, void* pFramesOut, ma_uint64 frameCount)
{
if (pNoise == NULL) {
@@ -40745,6 +40873,10 @@ ma_uint64 ma_noise_read_pcm_frames(ma_noise* pNoise, void* pFramesOut, ma_uint64
return ma_noise_read_pcm_frames__white(pNoise, pFramesOut, frameCount);
}
if (pNoise->config.type == ma_noise_type_pink) {
return ma_noise_read_pcm_frames__pink(pNoise, pFramesOut, frameCount);
}
/* Should never get here. */
MA_ASSERT(MA_FALSE);
return 0;