mirror/miniaudio
1
0
Fork 0
mirror of https://github.com/mackron/miniaudio.git synced 2026-04-24 01:04:02 +02:00
Code Issues Packages Projects Releases Wiki Activity

Add second order low shelf filter.

Browse Source
This commit is contained in:
David Reid
2020-02-23 21:03:22 +10:00
parent b6d0591042
commit 5b385670f3
3 changed files with 346 additions and 7 deletions
Download Patch File Download Diff File Expand all files Collapse all files
miniaudio.h
+169 -5
View File
@@ -1898,6 +1898,34 @@ ma_result ma_peak2_process_pcm_frames(ma_peak2* pFilter, void* pFramesOut, const
ma_uint32 ma_peak2_get_latency(ma_peak2* pFilter);
/**************************************************************************************************************************************************************
Low Shelf Filter
**************************************************************************************************************************************************************/
typedef struct
{
ma_format format;
ma_uint32 channels;
ma_uint32 sampleRate;
double gainDB;
double shelfSlope;
double frequency;
} ma_loshelf2_config;
ma_loshelf2_config ma_loshelf2_config_init(ma_format format, ma_uint32 channels, ma_uint32 sampleRate, double gainDB, double shelfSlope, double frequency);
typedef struct
{
ma_biquad bq;
} ma_loshelf2;
ma_result ma_loshelf2_init(const ma_loshelf2_config* pConfig, ma_loshelf2* pFilter);
ma_result ma_loshelf2_reinit(const ma_loshelf2_config* pConfig, ma_loshelf2* pFilter);
ma_result ma_loshelf2_process_pcm_frames(ma_loshelf2* pFilter, void* pFramesOut, const void* pFramesIn, ma_uint64 frameCount);
ma_uint32 ma_loshelf2_get_latency(ma_loshelf2* pFilter);
/************************************************************************************************************************************************************
*************************************************************************************************************************************************************
@@ -5725,11 +5753,6 @@ static MA_INLINE double ma_sin(double x)
return sin(x);
}
static MA_INLINE double ma_cos(double x)
{
return ma_sin((MA_PI*0.5) - x);
}
static MA_INLINE double ma_exp(double x)
{
/* TODO: Implement custom exp(x). */
@@ -5748,6 +5771,18 @@ static MA_INLINE double ma_pow(double x, double y)
return pow(x, y);
}
static MA_INLINE double ma_sqrt(double x)
{
/* TODO: Implement custom sqrt(x). */
return sqrt(x);
}
static MA_INLINE double ma_cos(double x)
{
return ma_sin((MA_PI*0.5) - x);
}
static MA_INLINE double ma_log10(double x)
{
return ma_log(x) * 0.43429448190325182765;
@@ -31148,6 +31183,135 @@ ma_uint32 ma_peak2_get_latency(ma_peak2* pFilter)
}
/**************************************************************************************************************************************************************
Low Shelf Filter
**************************************************************************************************************************************************************/
ma_loshelf2_config ma_loshelf2_config_init(ma_format format, ma_uint32 channels, ma_uint32 sampleRate, double gainDB, double shelfSlope, double frequency)
{
ma_loshelf2_config config;
MA_ZERO_OBJECT(&config);
config.format = format;
config.channels = channels;
config.sampleRate = sampleRate;
config.gainDB = gainDB;
config.shelfSlope = shelfSlope;
config.frequency = frequency;
if (config.gainDB == 0) {
config.gainDB = 6;
}
return config;
}
static MA_INLINE ma_biquad_config ma_loshelf2__get_biquad_config(const ma_loshelf2_config* pConfig)
{
ma_biquad_config bqConfig;
double w;
double s;
double c;
double A;
double S;
double a;
double sqrtA;
MA_ASSERT(pConfig != NULL);
w = 2 * MA_PI_D * pConfig->frequency / pConfig->sampleRate;
s = ma_sin(w);
c = ma_cos(w);
A = ma_pow(10, (pConfig->gainDB / 40));
S = pConfig->shelfSlope;
a = s/2 * ma_sqrt((A + 1/A) * (1/S - 1) + 2);
sqrtA = 2*ma_sqrt(A)*a;
bqConfig.b0 = A * ((A + 1) - (A - 1)*c + sqrtA);
bqConfig.b1 = 2 * A * ((A - 1) - (A + 1)*c);
bqConfig.b2 = A * ((A + 1) - (A - 1)*c - sqrtA);
bqConfig.a0 = (A + 1) + (A - 1)*c + sqrtA;
bqConfig.a1 = -2 * ((A - 1) + (A + 1)*c);
bqConfig.a2 = (A + 1) + (A - 1)*c - sqrtA;
bqConfig.format = pConfig->format;
bqConfig.channels = pConfig->channels;
return bqConfig;
}
ma_result ma_loshelf2_init(const ma_loshelf2_config* pConfig, ma_loshelf2* pFilter)
{
ma_result result;
ma_biquad_config bqConfig;
if (pFilter == NULL) {
return MA_INVALID_ARGS;
}
MA_ZERO_OBJECT(pFilter);
if (pConfig == NULL) {
return MA_INVALID_ARGS;
}
bqConfig = ma_loshelf2__get_biquad_config(pConfig);
result = ma_biquad_init(&bqConfig, &pFilter->bq);
if (result != MA_SUCCESS) {
return result;
}
return MA_SUCCESS;
}
ma_result ma_loshelf2_reinit(const ma_loshelf2_config* pConfig, ma_loshelf2* pFilter)
{
ma_result result;
ma_biquad_config bqConfig;
if (pFilter == NULL || pConfig == NULL) {
return MA_INVALID_ARGS;
}
bqConfig = ma_loshelf2__get_biquad_config(pConfig);
result = ma_biquad_reinit(&bqConfig, &pFilter->bq);
if (result != MA_SUCCESS) {
return result;
}
return MA_SUCCESS;
}
static MA_INLINE void ma_loshelf2_process_pcm_frame_s16(ma_loshelf2* pFilter, ma_int16* pFrameOut, const ma_int16* pFrameIn)
{
ma_biquad_process_pcm_frame_s16(&pFilter->bq, pFrameOut, pFrameIn);
}
static MA_INLINE void ma_loshelf2_process_pcm_frame_f32(ma_loshelf2* pFilter, float* pFrameOut, const float* pFrameIn)
{
ma_biquad_process_pcm_frame_f32(&pFilter->bq, pFrameOut, pFrameIn);
}
ma_result ma_loshelf2_process_pcm_frames(ma_loshelf2* pFilter, void* pFramesOut, const void* pFramesIn, ma_uint64 frameCount)
{
if (pFilter == NULL) {
return MA_INVALID_ARGS;
}
return ma_biquad_process_pcm_frames(&pFilter->bq, pFramesOut, pFramesIn, frameCount);
}
ma_uint32 ma_loshelf2_get_latency(ma_loshelf2* pFilter)
{
if (pFilter == NULL) {
return 0;
}
return ma_biquad_get_latency(&pFilter->bq);
}
/**************************************************************************************************************************************************************