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Updated Blam Synthesis resampler, improving quality and performance significantly.

CQTexperiment
Chris Moeller 2016-06-02 00:31:13 -07:00
parent 4fdbf35aba
commit 0213dd9741
3 changed files with 381 additions and 817 deletions
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402
Frameworks/Dumb/dumb/src/helpers/resampler.c
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@ -35,9 +35,9 @@ enum { RESAMPLER_RESOLUTION_EXTRA = 1 << (RESAMPLER_SHIFT + RESAMPLER_SHIFT_EXTR
enum { SINC_WIDTH = 16 }; enum { SINC_WIDTH = 16 };
enum { SINC_SAMPLES = RESAMPLER_RESOLUTION * SINC_WIDTH }; enum { SINC_SAMPLES = RESAMPLER_RESOLUTION * SINC_WIDTH };
enum { CUBIC_SAMPLES = RESAMPLER_RESOLUTION * 4 }; enum { CUBIC_SAMPLES = RESAMPLER_RESOLUTION * 4 };
enum { IIR_ORDER = 6 };
static const float RESAMPLER_BLEP_CUTOFF = 0.90f; static const float RESAMPLER_BLEP_CUTOFF = 0.90f;
static const float RESAMPLER_BLAM_CUTOFF = 0.93f;
static const float RESAMPLER_SINC_CUTOFF = 0.999f; static const float RESAMPLER_SINC_CUTOFF = 0.999f;
ALIGNED static float cubic_lut[CUBIC_SAMPLES]; ALIGNED static float cubic_lut[CUBIC_SAMPLES];
@ -138,6 +138,54 @@ void resampler_init(void)
#endif #endif
} }
typedef struct iir
{
double cutoff; //frequency cutoff
double quality; //frequency response quality
double gain; //peak gain
double a0, a1, a2, b1, b2; //coefficients
double z1, z2; //second-order IIR
} iir;
static void iir_reset(iir * i, double cutoff, double quality, double gain)
{
double v, k, q, n;
i->cutoff = cutoff;
i->quality = quality;
i->gain = gain;
v = pow(10, fabs(gain) / 20.0);
k = tan(M_PI * cutoff);
q = quality;
n = 1 / (1 + k / q + k * k);
i->a0 = k * k * n;
i->a1 = 2 * i->a0;
i->a2 = i->a0;
i->b1 = 2 * (k * k - 1) * n;
i->b2 = (1 - k / q + k * k) * n;
}
static void iir_clear(iir * i)
{
i->z1 = 0.0;
i->z2 = 0.0;
}
static double iir_process(iir * i, double in)
{
double out = in * i->a0 + i->z1;
i->z1 = in * i->a1 + i->z2 - i->b1 * out;
i->z2 = in * i->a2 - i->b2 * out;
return out;
}
static double butterworth(unsigned int order, unsigned int phase)
{
return -0.5 / cos(M_PI / 2.0 * (1.0 + (1.0 + (2.0 * phase + 1.0) / order)));
}
typedef struct resampler typedef struct resampler
{ {
int write_pos, write_filled; int write_pos, write_filled;
@ -149,10 +197,12 @@ typedef struct resampler
unsigned char quality; unsigned char quality;
signed char delay_added; signed char delay_added;
signed char delay_removed; signed char delay_removed;
unsigned char output_stage;
float last_amp; float last_amp;
float accumulator; float accumulator;
float buffer_in[resampler_buffer_size * 2]; float buffer_in[resampler_buffer_size * 2];
float buffer_out[resampler_buffer_size + SINC_WIDTH * 2 - 1]; float buffer_out[resampler_buffer_size + SINC_WIDTH * 2 - 1];
iir filter[IIR_ORDER / 2];
} resampler; } resampler;
void * resampler_create(void) void * resampler_create(void)
@ -171,10 +221,12 @@ void * resampler_create(void)
r->quality = RESAMPLER_QUALITY_MAX; r->quality = RESAMPLER_QUALITY_MAX;
r->delay_added = -1; r->delay_added = -1;
r->delay_removed = -1; r->delay_removed = -1;
r->output_stage = 0;
r->last_amp = 0; r->last_amp = 0;
r->accumulator = 0; r->accumulator = 0;
memset( r->buffer_in, 0, sizeof(r->buffer_in) ); memset( r->buffer_in, 0, sizeof(r->buffer_in) );
memset( r->buffer_out, 0, sizeof(r->buffer_out) ); memset( r->buffer_out, 0, sizeof(r->buffer_out) );
memset( r->filter, 0, sizeof(r->filter) );
return r; return r;
} }
@ -210,10 +262,12 @@ void resampler_dup_inplace(void *_d, const void *_s)
r_out->quality = r_in->quality; r_out->quality = r_in->quality;
r_out->delay_added = r_in->delay_added; r_out->delay_added = r_in->delay_added;
r_out->delay_removed = r_in->delay_removed; r_out->delay_removed = r_in->delay_removed;
r_out->output_stage = r_in->output_stage;
r_out->last_amp = r_in->last_amp; r_out->last_amp = r_in->last_amp;
r_out->accumulator = r_in->accumulator; r_out->accumulator = r_in->accumulator;
memcpy( r_out->buffer_in, r_in->buffer_in, sizeof(r_in->buffer_in) ); memcpy( r_out->buffer_in, r_in->buffer_in, sizeof(r_in->buffer_in) );
memcpy( r_out->buffer_out, r_in->buffer_out, sizeof(r_in->buffer_out) ); memcpy( r_out->buffer_out, r_in->buffer_out, sizeof(r_in->buffer_out) );
memcpy( r_out->filter, r_in->filter, sizeof(r_in->filter) );
} }
void resampler_set_quality(void *_r, int quality) void resampler_set_quality(void *_r, int quality)
@ -225,8 +279,7 @@ void resampler_set_quality(void *_r, int quality)
quality = RESAMPLER_QUALITY_MAX; quality = RESAMPLER_QUALITY_MAX;
if ( r->quality != quality ) if ( r->quality != quality )
{ {
if ( quality == RESAMPLER_QUALITY_BLEP || r->quality == RESAMPLER_QUALITY_BLEP || if ( quality == RESAMPLER_QUALITY_BLEP || r->quality == RESAMPLER_QUALITY_BLEP )
quality == RESAMPLER_QUALITY_BLAM || r->quality == RESAMPLER_QUALITY_BLAM )
{ {
r->read_pos = 0; r->read_pos = 0;
r->read_filled = 0; r->read_filled = 0;
@ -236,6 +289,8 @@ void resampler_set_quality(void *_r, int quality)
} }
r->delay_added = -1; r->delay_added = -1;
r->delay_removed = -1; r->delay_removed = -1;
if ( quality == RESAMPLER_QUALITY_BLAM && r->phase_inc )
resampler_set_rate( r, r->phase_inc );
} }
r->quality = (unsigned char)quality; r->quality = (unsigned char)quality;
} }
@ -293,16 +348,21 @@ static int resampler_output_delay(resampler *r)
default: default:
case RESAMPLER_QUALITY_ZOH: case RESAMPLER_QUALITY_ZOH:
case RESAMPLER_QUALITY_LINEAR: case RESAMPLER_QUALITY_LINEAR:
case RESAMPLER_QUALITY_BLAM:
case RESAMPLER_QUALITY_CUBIC: case RESAMPLER_QUALITY_CUBIC:
case RESAMPLER_QUALITY_SINC: case RESAMPLER_QUALITY_SINC:
return 0; return 0;
case RESAMPLER_QUALITY_BLEP: case RESAMPLER_QUALITY_BLEP:
case RESAMPLER_QUALITY_BLAM:
return SINC_WIDTH - 1; return SINC_WIDTH - 1;
} }
} }
int resampler_get_padding_size()
{
return SINC_WIDTH - 1;
}
int resampler_ready(void *_r) int resampler_ready(void *_r)
{ {
resampler * r = ( resampler * ) _r; resampler * r = ( resampler * ) _r;
@ -321,21 +381,48 @@ void resampler_clear(void *_r)
r->delay_removed = -1; r->delay_removed = -1;
memset(r->buffer_in, 0, (SINC_WIDTH - 1) * sizeof(r->buffer_in[0])); memset(r->buffer_in, 0, (SINC_WIDTH - 1) * sizeof(r->buffer_in[0]));
memset(r->buffer_in + resampler_buffer_size, 0, (SINC_WIDTH - 1) * sizeof(r->buffer_in[0])); memset(r->buffer_in + resampler_buffer_size, 0, (SINC_WIDTH - 1) * sizeof(r->buffer_in[0]));
if (r->quality == RESAMPLER_QUALITY_BLEP || r->quality == RESAMPLER_QUALITY_BLAM) if (r->quality == RESAMPLER_QUALITY_BLEP)
{ {
r->inv_phase = 0; r->inv_phase = 0;
r->last_amp = 0; r->last_amp = 0;
r->accumulator = 0; r->accumulator = 0;
memset(r->buffer_out, 0, sizeof(r->buffer_out)); memset(r->buffer_out, 0, sizeof(r->buffer_out));
} }
if (r->quality == RESAMPLER_QUALITY_BLAM)
{
unsigned int i, j;
for (i = 0, j = IIR_ORDER / 2; i < j; ++i)
iir_clear(r->filter + i);
}
} }
void resampler_set_rate(void *_r, double new_factor) void resampler_set_rate(void *_r, double new_factor)
{ {
resampler * r = ( resampler * ) _r; resampler * r = ( resampler * ) _r;
float old_phase_inc = r->phase_inc;
r->phase_inc = new_factor; r->phase_inc = new_factor;
new_factor = 1.0 / new_factor; new_factor = 1.0 / new_factor;
r->inv_phase_inc = new_factor; r->inv_phase_inc = new_factor;
if (r->quality == RESAMPLER_QUALITY_BLAM && old_phase_inc != r->phase_inc)
{
double ratio_ = new_factor;
unsigned int i, j;
r->output_stage = (ratio_ >= 1.0);
if (!r->output_stage)
{
ratio_ *= 0.45;
}
else
{
ratio_ = (1.0 / ratio_) * 0.45;
}
if (ratio_ > 0.45)
{
ratio_ = 0.45;
}
for (i = 0, j = IIR_ORDER / 2; i < j; ++i)
iir_reset(r->filter + i, ratio_, butterworth(IIR_ORDER, i), 0.0);
}
} }
void resampler_write_sample(void *_r, short s) void resampler_write_sample(void *_r, short s)
@ -350,8 +437,16 @@ void resampler_write_sample(void *_r, short s)
if ( r->write_filled < resampler_buffer_size ) if ( r->write_filled < resampler_buffer_size )
{ {
float s32 = s; double s32 = s;
s32 *= 256.0; s32 *= 256.0;
s32 += 1e-25;
if ( r->quality == RESAMPLER_QUALITY_BLAM && !r->output_stage )
{
unsigned int i, j;
for (i = 0, j = IIR_ORDER / 2; i < j; ++i)
s32 = iir_process(r->filter + i, s32);
}
r->buffer_in[ r->write_pos ] = s32; r->buffer_in[ r->write_pos ] = s32;
r->buffer_in[ r->write_pos + resampler_buffer_size ] = s32; r->buffer_in[ r->write_pos + resampler_buffer_size ] = s32;
@ -374,9 +469,17 @@ void resampler_write_sample_fixed(void *_r, int s, unsigned char depth)
if ( r->write_filled < resampler_buffer_size ) if ( r->write_filled < resampler_buffer_size )
{ {
float s32 = s; double s32 = s;
s32 /= (double)(1 << (depth - 1)); s32 /= (double)(1 << (depth - 1));
s32 += 1e-25;
if ( r->quality == RESAMPLER_QUALITY_BLAM && !r->output_stage )
{
unsigned int i, j;
for (i = 0, j = IIR_ORDER / 2; i < j; ++i)
s32 = iir_process(r->filter + i, s32);
}
r->buffer_in[ r->write_pos ] = s32; r->buffer_in[ r->write_pos ] = s32;
r->buffer_in[ r->write_pos + resampler_buffer_size ] = s32; r->buffer_in[ r->write_pos + resampler_buffer_size ] = s32;
@ -697,11 +800,11 @@ static int resampler_run_linear(resampler * r, float ** out_, float * out_end)
return used; return used;
} }
#ifndef RESAMPLER_NEON
static int resampler_run_blam(resampler * r, float ** out_, float * out_end) static int resampler_run_blam(resampler * r, float ** out_, float * out_end)
{ {
int in_size = r->write_filled; int in_size = r->write_filled;
float const* in_ = r->buffer_in + resampler_buffer_size + r->write_pos - r->write_filled; float const* in_ = r->buffer_in + resampler_buffer_size + r->write_pos - r->write_filled;
unsigned int output_stage = r->output_stage;
int used = 0; int used = 0;
in_size -= 2; in_size -= 2;
if ( in_size > 0 ) if ( in_size > 0 )
@ -709,66 +812,36 @@ static int resampler_run_blam(resampler * r, float ** out_, float * out_end)
float* out = *out_; float* out = *out_;
float const* in = in_; float const* in = in_;
float const* const in_end = in + in_size; float const* const in_end = in + in_size;
float last_amp = r->last_amp;
float phase = r->phase; float phase = r->phase;
float phase_inc = r->phase_inc; float phase_inc = r->phase_inc;
float inv_phase = r->inv_phase;
float inv_phase_inc = r->inv_phase_inc;
const int step = RESAMPLER_BLAM_CUTOFF * RESAMPLER_RESOLUTION;
const int window_step = RESAMPLER_RESOLUTION;
do do
{ {
float sample; float sample;
if ( out + SINC_WIDTH * 2 > out_end ) if ( out >= out_end )
break; break;
sample = in[0]; sample = in[0] + (in[1] - in[0]) * phase;
if (phase_inc < 1.0f)
sample += (in[1] - in[0]) * phase;
sample -= last_amp;
if (sample)
{
float kernel[SINC_WIDTH * 2], kernel_sum = 0.0f;
int phase_reduced = (int)(inv_phase * RESAMPLER_RESOLUTION);
int phase_adj = phase_reduced * step / RESAMPLER_RESOLUTION;
int i = SINC_WIDTH;
for (; i >= -SINC_WIDTH + 1; --i) if ( output_stage )
{ {
int pos = i * step; unsigned int i, j;
int window_pos = i * window_step; for (i = 0, j = IIR_ORDER / 2; i < j; ++i)
kernel_sum += kernel[i + SINC_WIDTH - 1] = sinc_lut[abs(phase_adj - pos)] * window_lut[abs(phase_reduced - window_pos)]; sample = iir_process(r->filter + i, sample);
}
last_amp += sample;
sample /= kernel_sum;
for (i = 0; i < SINC_WIDTH * 2; ++i)
out[i] += sample * kernel[i];
} }
*out++ = sample;
if (inv_phase_inc < 1.0f) phase += phase_inc;
{
++in; in += (int)phase;
inv_phase += inv_phase_inc;
out += (int)inv_phase; phase = fmod(phase, 1.0f);
inv_phase = fmod(inv_phase, 1.0f);
}
else
{
phase += phase_inc;
++out;
in += (int)phase;
phase = fmod(phase, 1.0f);
}
} }
while ( in < in_end ); while ( in < in_end );
r->phase = phase; r->phase = phase;
r->inv_phase = inv_phase;
r->last_amp = last_amp;
*out_ = out; *out_ = out;
used = (int)(in - in_); used = (int)(in - in_);
@ -778,204 +851,6 @@ static int resampler_run_blam(resampler * r, float ** out_, float * out_end)
return used; return used;
} }
#endif
#ifdef RESAMPLER_SSE
static int resampler_run_blam_sse(resampler * r, float ** out_, float * out_end)
{
int in_size = r->write_filled;
float const* in_ = r->buffer_in + resampler_buffer_size + r->write_pos - r->write_filled;
int used = 0;
in_size -= 2;
if ( in_size > 0 )
{
float* out = *out_;
float const* in = in_;
float const* const in_end = in + in_size;
float last_amp = r->last_amp;
float phase = r->phase;
float phase_inc = r->phase_inc;
float inv_phase = r->inv_phase;
float inv_phase_inc = r->inv_phase_inc;
const int step = RESAMPLER_BLAM_CUTOFF * RESAMPLER_RESOLUTION;
const int window_step = RESAMPLER_RESOLUTION;
do
{
float sample;
if ( out + SINC_WIDTH * 2 > out_end )
break;
sample = in[0];
if (phase_inc < 1.0f)
{
sample += (in[1] - in[0]) * phase;
}
sample -= last_amp;
if (sample)
{
float kernel_sum = 0.0f;
__m128 kernel[SINC_WIDTH / 2];
__m128 temp1, temp2;
__m128 samplex;
float *kernelf = (float*)(&kernel);
int phase_reduced = (int)(inv_phase * RESAMPLER_RESOLUTION);
int phase_adj = phase_reduced * step / RESAMPLER_RESOLUTION;
int i = SINC_WIDTH;
for (; i >= -SINC_WIDTH + 1; --i)
{
int pos = i * step;
int window_pos = i * window_step;
kernel_sum += kernelf[i + SINC_WIDTH - 1] = sinc_lut[abs(phase_adj - pos)] * window_lut[abs(phase_reduced - window_pos)];
}
last_amp += sample;
sample /= kernel_sum;
samplex = _mm_set1_ps( sample );
for (i = 0; i < SINC_WIDTH / 2; ++i)
{
temp1 = _mm_load_ps( (const float *)( kernel + i ) );
temp1 = _mm_mul_ps( temp1, samplex );
temp2 = _mm_loadu_ps( (const float *) out + i * 4 );
temp1 = _mm_add_ps( temp1, temp2 );
_mm_storeu_ps( (float *) out + i * 4, temp1 );
}
}
if (inv_phase_inc < 1.0f)
{
++in;
inv_phase += inv_phase_inc;
out += (int)inv_phase;
inv_phase = fmod(inv_phase, 1.0f);
}
else
{
phase += phase_inc;
++out;
if (phase >= 1.0f)
{
++in;
phase = fmod(phase, 1.0f);
}
}
}
while ( in < in_end );
r->phase = phase;
r->inv_phase = inv_phase;
r->last_amp = last_amp;
*out_ = out;
used = (int)(in - in_);
r->write_filled -= used;
}
return used;
}
#endif
#ifdef RESAMPLER_NEON
static int resampler_run_blam(resampler * r, float ** out_, float * out_end)
{
int in_size = r->write_filled;
float const* in_ = r->buffer_in + resampler_buffer_size + r->write_pos - r->write_filled;
int used = 0;
in_size -= 2;
if ( in_size > 0 )
{
float* out = *out_;
float const* in = in_;
float const* const in_end = in + in_size;
float last_amp = r->last_amp;
float phase = r->phase;
float phase_inc = r->phase_inc;
float inv_phase = r->inv_phase;
float inv_phase_inc = r->inv_phase_inc;
const int step = RESAMPLER_BLAM_CUTOFF * RESAMPLER_RESOLUTION;
const int window_step = RESAMPLER_RESOLUTION;
do
{
float sample;
if ( out + SINC_WIDTH * 2 > out_end )
break;
sample = in[0];
if (phase_inc < 1.0f)
sample += (in[1] - in[0]) * phase;
sample -= last_amp;
if (sample)
{
float kernel_sum = 0.0;
float32x4_t kernel[SINC_WIDTH / 2];
float32x4_t temp1, temp2;
float32x4_t samplex;
float *kernelf = (float*)(&kernel);
int phase_reduced = (int)(inv_phase * RESAMPLER_RESOLUTION);
int phase_adj = phase_reduced * step / RESAMPLER_RESOLUTION;
int i = SINC_WIDTH;
for (; i >= -SINC_WIDTH + 1; --i)
{
int pos = i * step;
int window_pos = i * window_step;
kernel_sum += kernelf[i + SINC_WIDTH - 1] = sinc_lut[abs(phase_adj - pos)] * window_lut[abs(phase_reduced - window_pos)];
}
last_amp += sample;
sample /= kernel_sum;
samplex = vdupq_n_f32(sample);
for (i = 0; i < SINC_WIDTH / 2; ++i)
{
temp1 = vld1q_f32( (const float32_t *)( kernel + i ) );
temp2 = vld1q_f32( (const float32_t *) out + i * 4 );
temp2 = vmlaq_f32( temp2, temp1, samplex );
vst1q_f32( (float32_t *) out + i * 4, temp2 );
}
}
if (inv_phase_inc < 1.0f)
{
++in;
inv_phase += inv_phase_inc;
out += (int)inv_phase;
inv_phase = fmod(inv_phase, 1.0f);
}
else
{
phase += phase_inc;
++out;
if (phase >= 1.0f)
{
++in;
phase = fmod(phase, 1.0f);
}
}
}
while ( in < in_end );
r->phase = phase;
r->inv_phase = inv_phase;
r->last_amp = last_amp;
*out_ = out;
used = (int)(in - in_);
r->write_filled -= used;
}
return used;
}
#endif
#ifndef RESAMPLER_NEON #ifndef RESAMPLER_NEON
static int resampler_run_cubic(resampler * r, float ** out_, float * out_end) static int resampler_run_cubic(resampler * r, float ** out_, float * out_end)
@ -1382,25 +1257,8 @@ static void resampler_fill(resampler * r)
break; break;
case RESAMPLER_QUALITY_BLAM: case RESAMPLER_QUALITY_BLAM:
{ resampler_run_blam( r, &out, out + write_size );
float * out_ = out;
int write_extra = 0;
if ( write_pos >= r->read_pos )
write_extra = r->read_pos;
if ( write_extra > SINC_WIDTH * 2 - 1 )
write_extra = SINC_WIDTH * 2 - 1;
memcpy( r->buffer_out + resampler_buffer_size, r->buffer_out, write_extra * sizeof(r->buffer_out[0]) );
#ifdef RESAMPLER_SSE
if ( resampler_has_sse )
resampler_run_blam_sse( r, &out, out + write_size + write_extra );
else
#endif
resampler_run_blam( r, &out, out + write_size + write_extra );
memcpy( r->buffer_out, r->buffer_out + resampler_buffer_size, write_extra * sizeof(r->buffer_out[0]) );
if ( out == out_ )
return;
break; break;
}
case RESAMPLER_QUALITY_CUBIC: case RESAMPLER_QUALITY_CUBIC:
#ifdef RESAMPLER_SSE #ifdef RESAMPLER_SSE
@ -1439,7 +1297,7 @@ static void resampler_fill_and_remove_delay(resampler * r)
int resampler_get_sample_count(void *_r) int resampler_get_sample_count(void *_r)
{ {
resampler * r = ( resampler * ) _r; resampler * r = ( resampler * ) _r;
if ( r->read_filled < 1 && ((r->quality != RESAMPLER_QUALITY_BLEP && r->quality != RESAMPLER_QUALITY_BLAM) || r->inv_phase_inc)) if ( r->read_filled < 1 && (r->quality != RESAMPLER_QUALITY_BLEP || r->inv_phase_inc) )
resampler_fill_and_remove_delay( r ); resampler_fill_and_remove_delay( r );
return r->read_filled; return r->read_filled;
} }
@ -1451,7 +1309,7 @@ int resampler_get_sample(void *_r)
resampler_fill_and_remove_delay( r ); resampler_fill_and_remove_delay( r );
if ( r->read_filled < 1 ) if ( r->read_filled < 1 )
return 0; return 0;
if ( r->quality == RESAMPLER_QUALITY_BLEP || r->quality == RESAMPLER_QUALITY_BLAM ) if ( r->quality == RESAMPLER_QUALITY_BLEP )
return (int)(r->buffer_out[ r->read_pos ] + r->accumulator); return (int)(r->buffer_out[ r->read_pos ] + r->accumulator);
else else
return (int)r->buffer_out[ r->read_pos ]; return (int)r->buffer_out[ r->read_pos ];
@ -1464,7 +1322,7 @@ float resampler_get_sample_float(void *_r)
resampler_fill_and_remove_delay( r ); resampler_fill_and_remove_delay( r );
if ( r->read_filled < 1 ) if ( r->read_filled < 1 )
return 0; return 0;
if ( r->quality == RESAMPLER_QUALITY_BLEP || r->quality == RESAMPLER_QUALITY_BLAM ) if ( r->quality == RESAMPLER_QUALITY_BLEP )
return r->buffer_out[ r->read_pos ] + r->accumulator; return r->buffer_out[ r->read_pos ] + r->accumulator;
else else
return r->buffer_out[ r->read_pos ]; return r->buffer_out[ r->read_pos ];
@ -1475,7 +1333,7 @@ void resampler_remove_sample(void *_r, int decay)
resampler * r = ( resampler * ) _r; resampler * r = ( resampler * ) _r;
if ( r->read_filled > 0 ) if ( r->read_filled > 0 )
{ {
if ( r->quality == RESAMPLER_QUALITY_BLEP || r->quality == RESAMPLER_QUALITY_BLAM ) if ( r->quality == RESAMPLER_QUALITY_BLEP )
{ {
r->accumulator += r->buffer_out[ r->read_pos ]; r->accumulator += r->buffer_out[ r->read_pos ];
r->buffer_out[ r->read_pos ] = 0; r->buffer_out[ r->read_pos ] = 0;

399
Frameworks/modplay/modplay/resampler.c
View File

@ -35,9 +35,9 @@ enum { RESAMPLER_RESOLUTION_EXTRA = 1 << (RESAMPLER_SHIFT + RESAMPLER_SHIFT_EXTR
enum { SINC_WIDTH = 16 }; enum { SINC_WIDTH = 16 };
enum { SINC_SAMPLES = RESAMPLER_RESOLUTION * SINC_WIDTH }; enum { SINC_SAMPLES = RESAMPLER_RESOLUTION * SINC_WIDTH };
enum { CUBIC_SAMPLES = RESAMPLER_RESOLUTION * 4 }; enum { CUBIC_SAMPLES = RESAMPLER_RESOLUTION * 4 };
enum { IIR_ORDER = 6 };
static const float RESAMPLER_BLEP_CUTOFF = 0.90f; static const float RESAMPLER_BLEP_CUTOFF = 0.90f;
static const float RESAMPLER_BLAM_CUTOFF = 0.93f;
static const float RESAMPLER_SINC_CUTOFF = 0.999f; static const float RESAMPLER_SINC_CUTOFF = 0.999f;
ALIGNED static float cubic_lut[CUBIC_SAMPLES]; ALIGNED static float cubic_lut[CUBIC_SAMPLES];
@ -138,6 +138,54 @@ void resampler_init(void)
#endif #endif
} }
typedef struct iir
{
double cutoff; //frequency cutoff
double quality; //frequency response quality
double gain; //peak gain
double a0, a1, a2, b1, b2; //coefficients
double z1, z2; //second-order IIR
} iir;
static void iir_reset(iir * i, double cutoff, double quality, double gain)
{
double v, k, q, n;
i->cutoff = cutoff;
i->quality = quality;
i->gain = gain;
v = pow(10, fabs(gain) / 20.0);
k = tan(M_PI * cutoff);
q = quality;
n = 1 / (1 + k / q + k * k);
i->a0 = k * k * n;
i->a1 = 2 * i->a0;
i->a2 = i->a0;
i->b1 = 2 * (k * k - 1) * n;
i->b2 = (1 - k / q + k * k) * n;
}
static void iir_clear(iir * i)
{
i->z1 = 0.0;
i->z2 = 0.0;
}
static double iir_process(iir * i, double in)
{
double out = in * i->a0 + i->z1;
i->z1 = in * i->a1 + i->z2 - i->b1 * out;
i->z2 = in * i->a2 - i->b2 * out;
return out;
}
static double butterworth(unsigned int order, unsigned int phase)
{
return -0.5 / cos(M_PI / 2.0 * (1.0 + (1.0 + (2.0 * phase + 1.0) / order)));
}
typedef struct resampler typedef struct resampler
{ {
int write_pos, write_filled; int write_pos, write_filled;
@ -149,10 +197,12 @@ typedef struct resampler
unsigned char quality; unsigned char quality;
signed char delay_added; signed char delay_added;
signed char delay_removed; signed char delay_removed;
unsigned char output_stage;
float last_amp; float last_amp;
float accumulator; float accumulator;
float buffer_in[resampler_buffer_size * 2]; float buffer_in[resampler_buffer_size * 2];
float buffer_out[resampler_buffer_size + SINC_WIDTH * 2 - 1]; float buffer_out[resampler_buffer_size + SINC_WIDTH * 2 - 1];
iir filter[IIR_ORDER / 2];
} resampler; } resampler;
void * resampler_create(void) void * resampler_create(void)
@ -171,10 +221,12 @@ void * resampler_create(void)
r->quality = RESAMPLER_QUALITY_MAX; r->quality = RESAMPLER_QUALITY_MAX;
r->delay_added = -1; r->delay_added = -1;
r->delay_removed = -1; r->delay_removed = -1;
r->output_stage = 0;
r->last_amp = 0; r->last_amp = 0;
r->accumulator = 0; r->accumulator = 0;
memset( r->buffer_in, 0, sizeof(r->buffer_in) ); memset( r->buffer_in, 0, sizeof(r->buffer_in) );
memset( r->buffer_out, 0, sizeof(r->buffer_out) ); memset( r->buffer_out, 0, sizeof(r->buffer_out) );
memset( r->filter, 0, sizeof(r->filter) );
return r; return r;
} }
@ -210,10 +262,12 @@ void resampler_dup_inplace(void *_d, const void *_s)
r_out->quality = r_in->quality; r_out->quality = r_in->quality;
r_out->delay_added = r_in->delay_added; r_out->delay_added = r_in->delay_added;
r_out->delay_removed = r_in->delay_removed; r_out->delay_removed = r_in->delay_removed;
r_out->output_stage = r_in->output_stage;
r_out->last_amp = r_in->last_amp; r_out->last_amp = r_in->last_amp;
r_out->accumulator = r_in->accumulator; r_out->accumulator = r_in->accumulator;
memcpy( r_out->buffer_in, r_in->buffer_in, sizeof(r_in->buffer_in) ); memcpy( r_out->buffer_in, r_in->buffer_in, sizeof(r_in->buffer_in) );
memcpy( r_out->buffer_out, r_in->buffer_out, sizeof(r_in->buffer_out) ); memcpy( r_out->buffer_out, r_in->buffer_out, sizeof(r_in->buffer_out) );
memcpy( r_out->filter, r_in->filter, sizeof(r_in->filter) );
} }
void resampler_set_quality(void *_r, int quality) void resampler_set_quality(void *_r, int quality)
@ -225,8 +279,7 @@ void resampler_set_quality(void *_r, int quality)
quality = RESAMPLER_QUALITY_MAX; quality = RESAMPLER_QUALITY_MAX;
if ( r->quality != quality ) if ( r->quality != quality )
{ {
if ( quality == RESAMPLER_QUALITY_BLEP || r->quality == RESAMPLER_QUALITY_BLEP || if ( quality == RESAMPLER_QUALITY_BLEP || r->quality == RESAMPLER_QUALITY_BLEP )
quality == RESAMPLER_QUALITY_BLAM || r->quality == RESAMPLER_QUALITY_BLAM )
{ {
r->read_pos = 0; r->read_pos = 0;
r->read_filled = 0; r->read_filled = 0;
@ -236,6 +289,8 @@ void resampler_set_quality(void *_r, int quality)
} }
r->delay_added = -1; r->delay_added = -1;
r->delay_removed = -1; r->delay_removed = -1;
if ( quality == RESAMPLER_QUALITY_BLAM && r->phase_inc )
resampler_set_rate( r, r->phase_inc );
} }
r->quality = (unsigned char)quality; r->quality = (unsigned char)quality;
} }
@ -293,12 +348,12 @@ static int resampler_output_delay(resampler *r)
default: default:
case RESAMPLER_QUALITY_ZOH: case RESAMPLER_QUALITY_ZOH:
case RESAMPLER_QUALITY_LINEAR: case RESAMPLER_QUALITY_LINEAR:
case RESAMPLER_QUALITY_BLAM:
case RESAMPLER_QUALITY_CUBIC: case RESAMPLER_QUALITY_CUBIC:
case RESAMPLER_QUALITY_SINC: case RESAMPLER_QUALITY_SINC:
return 0; return 0;
case RESAMPLER_QUALITY_BLEP: case RESAMPLER_QUALITY_BLEP:
case RESAMPLER_QUALITY_BLAM:
return SINC_WIDTH - 1; return SINC_WIDTH - 1;
} }
} }
@ -326,21 +381,48 @@ void resampler_clear(void *_r)
r->delay_removed = -1; r->delay_removed = -1;
memset(r->buffer_in, 0, (SINC_WIDTH - 1) * sizeof(r->buffer_in[0])); memset(r->buffer_in, 0, (SINC_WIDTH - 1) * sizeof(r->buffer_in[0]));
memset(r->buffer_in + resampler_buffer_size, 0, (SINC_WIDTH - 1) * sizeof(r->buffer_in[0])); memset(r->buffer_in + resampler_buffer_size, 0, (SINC_WIDTH - 1) * sizeof(r->buffer_in[0]));
if (r->quality == RESAMPLER_QUALITY_BLEP || r->quality == RESAMPLER_QUALITY_BLAM) if (r->quality == RESAMPLER_QUALITY_BLEP)
{ {
r->inv_phase = 0; r->inv_phase = 0;
r->last_amp = 0; r->last_amp = 0;
r->accumulator = 0; r->accumulator = 0;
memset(r->buffer_out, 0, sizeof(r->buffer_out)); memset(r->buffer_out, 0, sizeof(r->buffer_out));
} }
if (r->quality == RESAMPLER_QUALITY_BLAM)
{
unsigned int i, j;
for (i = 0, j = IIR_ORDER / 2; i < j; ++i)
iir_clear(r->filter + i);
}
} }
void resampler_set_rate(void *_r, double new_factor) void resampler_set_rate(void *_r, double new_factor)
{ {
resampler * r = ( resampler * ) _r; resampler * r = ( resampler * ) _r;
float old_phase_inc = r->phase_inc;
r->phase_inc = new_factor; r->phase_inc = new_factor;
new_factor = 1.0 / new_factor; new_factor = 1.0 / new_factor;
r->inv_phase_inc = new_factor; r->inv_phase_inc = new_factor;
if (r->quality == RESAMPLER_QUALITY_BLAM && old_phase_inc != r->phase_inc)
{
double ratio_ = new_factor;
unsigned int i, j;
r->output_stage = (ratio_ >= 1.0);
if (!r->output_stage)
{
ratio_ *= 0.45;
}
else
{
ratio_ = (1.0 / ratio_) * 0.45;
}
if (ratio_ > 0.45)
{
ratio_ = 0.45;
}
for (i = 0, j = IIR_ORDER / 2; i < j; ++i)
iir_reset(r->filter + i, ratio_, butterworth(IIR_ORDER, i), 0.0);
}
} }
void resampler_write_sample(void *_r, short s) void resampler_write_sample(void *_r, short s)
@ -355,8 +437,16 @@ void resampler_write_sample(void *_r, short s)
if ( r->write_filled < resampler_buffer_size ) if ( r->write_filled < resampler_buffer_size )
{ {
float s32 = s; double s32 = s;
s32 *= 256.0; s32 *= 256.0;
s32 += 1e-25;
if ( r->quality == RESAMPLER_QUALITY_BLAM && !r->output_stage )
{
unsigned int i, j;
for (i = 0, j = IIR_ORDER / 2; i < j; ++i)
s32 = iir_process(r->filter + i, s32);
}
r->buffer_in[ r->write_pos ] = s32; r->buffer_in[ r->write_pos ] = s32;
r->buffer_in[ r->write_pos + resampler_buffer_size ] = s32; r->buffer_in[ r->write_pos + resampler_buffer_size ] = s32;
@ -379,9 +469,17 @@ void resampler_write_sample_fixed(void *_r, int s, unsigned char depth)
if ( r->write_filled < resampler_buffer_size ) if ( r->write_filled < resampler_buffer_size )
{ {
float s32 = s; double s32 = s;
s32 /= (double)(1 << (depth - 1)); s32 /= (double)(1 << (depth - 1));
s32 += 1e-25;
if ( r->quality == RESAMPLER_QUALITY_BLAM && !r->output_stage )
{
unsigned int i, j;
for (i = 0, j = IIR_ORDER / 2; i < j; ++i)
s32 = iir_process(r->filter + i, s32);
}
r->buffer_in[ r->write_pos ] = s32; r->buffer_in[ r->write_pos ] = s32;
r->buffer_in[ r->write_pos + resampler_buffer_size ] = s32; r->buffer_in[ r->write_pos + resampler_buffer_size ] = s32;
@ -702,11 +800,11 @@ static int resampler_run_linear(resampler * r, float ** out_, float * out_end)
return used; return used;
} }
#ifndef RESAMPLER_NEON
static int resampler_run_blam(resampler * r, float ** out_, float * out_end) static int resampler_run_blam(resampler * r, float ** out_, float * out_end)
{ {
int in_size = r->write_filled; int in_size = r->write_filled;
float const* in_ = r->buffer_in + resampler_buffer_size + r->write_pos - r->write_filled; float const* in_ = r->buffer_in + resampler_buffer_size + r->write_pos - r->write_filled;
unsigned int output_stage = r->output_stage;
int used = 0; int used = 0;
in_size -= 2; in_size -= 2;
if ( in_size > 0 ) if ( in_size > 0 )
@ -714,66 +812,36 @@ static int resampler_run_blam(resampler * r, float ** out_, float * out_end)
float* out = *out_; float* out = *out_;
float const* in = in_; float const* in = in_;
float const* const in_end = in + in_size; float const* const in_end = in + in_size;
float last_amp = r->last_amp;
float phase = r->phase; float phase = r->phase;
float phase_inc = r->phase_inc; float phase_inc = r->phase_inc;
float inv_phase = r->inv_phase;
float inv_phase_inc = r->inv_phase_inc;
const int step = RESAMPLER_BLAM_CUTOFF * RESAMPLER_RESOLUTION;
const int window_step = RESAMPLER_RESOLUTION;
do do
{ {
float sample; float sample;
if ( out + SINC_WIDTH * 2 > out_end ) if ( out >= out_end )
break; break;
sample = in[0]; sample = in[0] + (in[1] - in[0]) * phase;
if (phase_inc < 1.0f)
sample += (in[1] - in[0]) * phase;
sample -= last_amp;
if (sample)
{
float kernel[SINC_WIDTH * 2], kernel_sum = 0.0f;
int phase_reduced = (int)(inv_phase * RESAMPLER_RESOLUTION);
int phase_adj = phase_reduced * step / RESAMPLER_RESOLUTION;
int i = SINC_WIDTH;
for (; i >= -SINC_WIDTH + 1; --i) if ( output_stage )
{ {
int pos = i * step; unsigned int i, j;
int window_pos = i * window_step; for (i = 0, j = IIR_ORDER / 2; i < j; ++i)
kernel_sum += kernel[i + SINC_WIDTH - 1] = sinc_lut[abs(phase_adj - pos)] * window_lut[abs(phase_reduced - window_pos)]; sample = iir_process(r->filter + i, sample);
}
last_amp += sample;
sample /= kernel_sum;
for (i = 0; i < SINC_WIDTH * 2; ++i)
out[i] += sample * kernel[i];
} }
*out++ = sample;
if (inv_phase_inc < 1.0f) phase += phase_inc;
{
++in; in += (int)phase;
inv_phase += inv_phase_inc;
out += (int)inv_phase; phase = fmod(phase, 1.0f);
inv_phase = fmod(inv_phase, 1.0f);
}
else
{
phase += phase_inc;
++out;
in += (int)phase;
phase = fmod(phase, 1.0f);
}
} }
while ( in < in_end ); while ( in < in_end );
r->phase = phase; r->phase = phase;
r->inv_phase = inv_phase;
r->last_amp = last_amp;
*out_ = out; *out_ = out;
used = (int)(in - in_); used = (int)(in - in_);
@ -783,204 +851,6 @@ static int resampler_run_blam(resampler * r, float ** out_, float * out_end)
return used; return used;
} }
#endif
#ifdef RESAMPLER_SSE
static int resampler_run_blam_sse(resampler * r, float ** out_, float * out_end)
{
int in_size = r->write_filled;
float const* in_ = r->buffer_in + resampler_buffer_size + r->write_pos - r->write_filled;
int used = 0;
in_size -= 2;
if ( in_size > 0 )
{
float* out = *out_;
float const* in = in_;
float const* const in_end = in + in_size;
float last_amp = r->last_amp;
float phase = r->phase;
float phase_inc = r->phase_inc;
float inv_phase = r->inv_phase;
float inv_phase_inc = r->inv_phase_inc;
const int step = RESAMPLER_BLAM_CUTOFF * RESAMPLER_RESOLUTION;
const int window_step = RESAMPLER_RESOLUTION;
do
{
float sample;
if ( out + SINC_WIDTH * 2 > out_end )
break;
sample = in[0];
if (phase_inc < 1.0f)
{
sample += (in[1] - in[0]) * phase;
}
sample -= last_amp;
if (sample)
{
float kernel_sum = 0.0f;
__m128 kernel[SINC_WIDTH / 2];
__m128 temp1, temp2;
__m128 samplex;
float *kernelf = (float*)(&kernel);
int phase_reduced = (int)(inv_phase * RESAMPLER_RESOLUTION);
int phase_adj = phase_reduced * step / RESAMPLER_RESOLUTION;
int i = SINC_WIDTH;
for (; i >= -SINC_WIDTH + 1; --i)
{
int pos = i * step;
int window_pos = i * window_step;
kernel_sum += kernelf[i + SINC_WIDTH - 1] = sinc_lut[abs(phase_adj - pos)] * window_lut[abs(phase_reduced - window_pos)];
}
last_amp += sample;
sample /= kernel_sum;
samplex = _mm_set1_ps( sample );
for (i = 0; i < SINC_WIDTH / 2; ++i)
{
temp1 = _mm_load_ps( (const float *)( kernel + i ) );
temp1 = _mm_mul_ps( temp1, samplex );
temp2 = _mm_loadu_ps( (const float *) out + i * 4 );
temp1 = _mm_add_ps( temp1, temp2 );
_mm_storeu_ps( (float *) out + i * 4, temp1 );
}
}
if (inv_phase_inc < 1.0f)
{
++in;
inv_phase += inv_phase_inc;
out += (int)inv_phase;
inv_phase = fmod(inv_phase, 1.0f);
}
else
{
phase += phase_inc;
++out;
if (phase >= 1.0f)
{
++in;
phase = fmod(phase, 1.0f);
}
}
}
while ( in < in_end );
r->phase = phase;
r->inv_phase = inv_phase;
r->last_amp = last_amp;
*out_ = out;
used = (int)(in - in_);
r->write_filled -= used;
}
return used;
}
#endif
#ifdef RESAMPLER_NEON
static int resampler_run_blam(resampler * r, float ** out_, float * out_end)
{
int in_size = r->write_filled;
float const* in_ = r->buffer_in + resampler_buffer_size + r->write_pos - r->write_filled;
int used = 0;
in_size -= 2;
if ( in_size > 0 )
{
float* out = *out_;
float const* in = in_;
float const* const in_end = in + in_size;
float last_amp = r->last_amp;
float phase = r->phase;
float phase_inc = r->phase_inc;
float inv_phase = r->inv_phase;
float inv_phase_inc = r->inv_phase_inc;
const int step = RESAMPLER_BLAM_CUTOFF * RESAMPLER_RESOLUTION;
const int window_step = RESAMPLER_RESOLUTION;
do
{
float sample;
if ( out + SINC_WIDTH * 2 > out_end )
break;
sample = in[0];
if (phase_inc < 1.0f)
sample += (in[1] - in[0]) * phase;
sample -= last_amp;
if (sample)
{
float kernel_sum = 0.0;
float32x4_t kernel[SINC_WIDTH / 2];
float32x4_t temp1, temp2;
float32x4_t samplex;
float *kernelf = (float*)(&kernel);
int phase_reduced = (int)(inv_phase * RESAMPLER_RESOLUTION);
int phase_adj = phase_reduced * step / RESAMPLER_RESOLUTION;
int i = SINC_WIDTH;
for (; i >= -SINC_WIDTH + 1; --i)
{
int pos = i * step;
int window_pos = i * window_step;
kernel_sum += kernelf[i + SINC_WIDTH - 1] = sinc_lut[abs(phase_adj - pos)] * window_lut[abs(phase_reduced - window_pos)];
}
last_amp += sample;
sample /= kernel_sum;
samplex = vdupq_n_f32(sample);
for (i = 0; i < SINC_WIDTH / 2; ++i)
{
temp1 = vld1q_f32( (const float32_t *)( kernel + i ) );
temp2 = vld1q_f32( (const float32_t *) out + i * 4 );
temp2 = vmlaq_f32( temp2, temp1, samplex );
vst1q_f32( (float32_t *) out + i * 4, temp2 );
}
}
if (inv_phase_inc < 1.0f)
{
++in;
inv_phase += inv_phase_inc;
out += (int)inv_phase;
inv_phase = fmod(inv_phase, 1.0f);
}
else
{
phase += phase_inc;
++out;
if (phase >= 1.0f)
{
++in;
phase = fmod(phase, 1.0f);
}
}
}
while ( in < in_end );
r->phase = phase;
r->inv_phase = inv_phase;
r->last_amp = last_amp;
*out_ = out;
used = (int)(in - in_);
r->write_filled -= used;
}
return used;
}
#endif
#ifndef RESAMPLER_NEON #ifndef RESAMPLER_NEON
static int resampler_run_cubic(resampler * r, float ** out_, float * out_end) static int resampler_run_cubic(resampler * r, float ** out_, float * out_end)
@ -1218,7 +1088,7 @@ static int resampler_run_sinc_sse(resampler * r, float ** out_, float * out_end)
// accumulate in extended precision // accumulate in extended precision
float kernel_sum = 0.0; float kernel_sum = 0.0;
__m128 kernel[SINC_WIDTH / 2]; __m128 kernel[SINC_WIDTH / 2];
__m128 temp1 = {0}, temp2; __m128 temp1, temp2;
__m128 samplex = _mm_setzero_ps(); __m128 samplex = _mm_setzero_ps();
float *kernelf = (float*)(&kernel); float *kernelf = (float*)(&kernel);
int i = SINC_WIDTH; int i = SINC_WIDTH;
@ -1387,25 +1257,8 @@ static void resampler_fill(resampler * r)
break; break;
case RESAMPLER_QUALITY_BLAM: case RESAMPLER_QUALITY_BLAM:
{ resampler_run_blam( r, &out, out + write_size );
float * out_ = out;
int write_extra = 0;
if ( write_pos >= r->read_pos )
write_extra = r->read_pos;
if ( write_extra > SINC_WIDTH * 2 - 1 )
write_extra = SINC_WIDTH * 2 - 1;
memcpy( r->buffer_out + resampler_buffer_size, r->buffer_out, write_extra * sizeof(r->buffer_out[0]) );
#ifdef RESAMPLER_SSE
if ( resampler_has_sse )
resampler_run_blam_sse( r, &out, out + write_size + write_extra );
else
#endif
resampler_run_blam( r, &out, out + write_size + write_extra );
memcpy( r->buffer_out, r->buffer_out + resampler_buffer_size, write_extra * sizeof(r->buffer_out[0]) );
if ( out == out_ )
return;
break; break;
}
case RESAMPLER_QUALITY_CUBIC: case RESAMPLER_QUALITY_CUBIC:
#ifdef RESAMPLER_SSE #ifdef RESAMPLER_SSE
@ -1444,7 +1297,7 @@ static void resampler_fill_and_remove_delay(resampler * r)
int resampler_get_sample_count(void *_r) int resampler_get_sample_count(void *_r)
{ {
resampler * r = ( resampler * ) _r; resampler * r = ( resampler * ) _r;
if ( r->read_filled < 1 && ((r->quality != RESAMPLER_QUALITY_BLEP && r->quality != RESAMPLER_QUALITY_BLAM) || r->inv_phase_inc)) if ( r->read_filled < 1 && (r->quality != RESAMPLER_QUALITY_BLEP || r->inv_phase_inc) )
resampler_fill_and_remove_delay( r ); resampler_fill_and_remove_delay( r );
return r->read_filled; return r->read_filled;
} }
@ -1456,7 +1309,7 @@ int resampler_get_sample(void *_r)
resampler_fill_and_remove_delay( r ); resampler_fill_and_remove_delay( r );
if ( r->read_filled < 1 ) if ( r->read_filled < 1 )
return 0; return 0;
if ( r->quality == RESAMPLER_QUALITY_BLEP || r->quality == RESAMPLER_QUALITY_BLAM ) if ( r->quality == RESAMPLER_QUALITY_BLEP )
return (int)(r->buffer_out[ r->read_pos ] + r->accumulator); return (int)(r->buffer_out[ r->read_pos ] + r->accumulator);
else else
return (int)r->buffer_out[ r->read_pos ]; return (int)r->buffer_out[ r->read_pos ];
@ -1469,7 +1322,7 @@ float resampler_get_sample_float(void *_r)
resampler_fill_and_remove_delay( r ); resampler_fill_and_remove_delay( r );
if ( r->read_filled < 1 ) if ( r->read_filled < 1 )
return 0; return 0;
if ( r->quality == RESAMPLER_QUALITY_BLEP || r->quality == RESAMPLER_QUALITY_BLAM ) if ( r->quality == RESAMPLER_QUALITY_BLEP )
return r->buffer_out[ r->read_pos ] + r->accumulator; return r->buffer_out[ r->read_pos ] + r->accumulator;
else else
return r->buffer_out[ r->read_pos ]; return r->buffer_out[ r->read_pos ];
@ -1480,7 +1333,7 @@ void resampler_remove_sample(void *_r, int decay)
resampler * r = ( resampler * ) _r; resampler * r = ( resampler * ) _r;
if ( r->read_filled > 0 ) if ( r->read_filled > 0 )
{ {
if ( r->quality == RESAMPLER_QUALITY_BLEP || r->quality == RESAMPLER_QUALITY_BLAM ) if ( r->quality == RESAMPLER_QUALITY_BLEP )
{ {
r->accumulator += r->buffer_out[ r->read_pos ]; r->accumulator += r->buffer_out[ r->read_pos ];
r->buffer_out[ r->read_pos ] = 0; r->buffer_out[ r->read_pos ] = 0;

397
Frameworks/playptmod/playptmod/resampler.c
View File

@ -35,9 +35,9 @@ enum { RESAMPLER_RESOLUTION_EXTRA = 1 << (RESAMPLER_SHIFT + RESAMPLER_SHIFT_EXTR
enum { SINC_WIDTH = 16 }; enum { SINC_WIDTH = 16 };
enum { SINC_SAMPLES = RESAMPLER_RESOLUTION * SINC_WIDTH }; enum { SINC_SAMPLES = RESAMPLER_RESOLUTION * SINC_WIDTH };
enum { CUBIC_SAMPLES = RESAMPLER_RESOLUTION * 4 }; enum { CUBIC_SAMPLES = RESAMPLER_RESOLUTION * 4 };
enum { IIR_ORDER = 6 };
static const float RESAMPLER_BLEP_CUTOFF = 0.90f; static const float RESAMPLER_BLEP_CUTOFF = 0.90f;
static const float RESAMPLER_BLAM_CUTOFF = 0.93f;
static const float RESAMPLER_SINC_CUTOFF = 0.999f; static const float RESAMPLER_SINC_CUTOFF = 0.999f;
ALIGNED static float cubic_lut[CUBIC_SAMPLES]; ALIGNED static float cubic_lut[CUBIC_SAMPLES];
@ -138,6 +138,54 @@ void resampler_init(void)
#endif #endif
} }
typedef struct iir
{
double cutoff; //frequency cutoff
double quality; //frequency response quality
double gain; //peak gain
double a0, a1, a2, b1, b2; //coefficients
double z1, z2; //second-order IIR
} iir;
static void iir_reset(iir * i, double cutoff, double quality, double gain)
{
double v, k, q, n;
i->cutoff = cutoff;
i->quality = quality;
i->gain = gain;
v = pow(10, fabs(gain) / 20.0);
k = tan(M_PI * cutoff);
q = quality;
n = 1 / (1 + k / q + k * k);
i->a0 = k * k * n;
i->a1 = 2 * i->a0;
i->a2 = i->a0;
i->b1 = 2 * (k * k - 1) * n;
i->b2 = (1 - k / q + k * k) * n;
}
static void iir_clear(iir * i)
{
i->z1 = 0.0;
i->z2 = 0.0;
}
static double iir_process(iir * i, double in)
{
double out = in * i->a0 + i->z1;
i->z1 = in * i->a1 + i->z2 - i->b1 * out;
i->z2 = in * i->a2 - i->b2 * out;
return out;
}
static double butterworth(unsigned int order, unsigned int phase)
{
return -0.5 / cos(M_PI / 2.0 * (1.0 + (1.0 + (2.0 * phase + 1.0) / order)));
}
typedef struct resampler typedef struct resampler
{ {
int write_pos, write_filled; int write_pos, write_filled;
@ -149,10 +197,12 @@ typedef struct resampler
unsigned char quality; unsigned char quality;
signed char delay_added; signed char delay_added;
signed char delay_removed; signed char delay_removed;
unsigned char output_stage;
float last_amp; float last_amp;
float accumulator; float accumulator;
float buffer_in[resampler_buffer_size * 2]; float buffer_in[resampler_buffer_size * 2];
float buffer_out[resampler_buffer_size + SINC_WIDTH * 2 - 1]; float buffer_out[resampler_buffer_size + SINC_WIDTH * 2 - 1];
iir filter[IIR_ORDER / 2];
} resampler; } resampler;
void * resampler_create(void) void * resampler_create(void)
@ -171,10 +221,12 @@ void * resampler_create(void)
r->quality = RESAMPLER_QUALITY_MAX; r->quality = RESAMPLER_QUALITY_MAX;
r->delay_added = -1; r->delay_added = -1;
r->delay_removed = -1; r->delay_removed = -1;
r->output_stage = 0;
r->last_amp = 0; r->last_amp = 0;
r->accumulator = 0; r->accumulator = 0;
memset( r->buffer_in, 0, sizeof(r->buffer_in) ); memset( r->buffer_in, 0, sizeof(r->buffer_in) );
memset( r->buffer_out, 0, sizeof(r->buffer_out) ); memset( r->buffer_out, 0, sizeof(r->buffer_out) );
memset( r->filter, 0, sizeof(r->filter) );
return r; return r;
} }
@ -210,10 +262,12 @@ void resampler_dup_inplace(void *_d, const void *_s)
r_out->quality = r_in->quality; r_out->quality = r_in->quality;
r_out->delay_added = r_in->delay_added; r_out->delay_added = r_in->delay_added;
r_out->delay_removed = r_in->delay_removed; r_out->delay_removed = r_in->delay_removed;
r_out->output_stage = r_in->output_stage;
r_out->last_amp = r_in->last_amp; r_out->last_amp = r_in->last_amp;
r_out->accumulator = r_in->accumulator; r_out->accumulator = r_in->accumulator;
memcpy( r_out->buffer_in, r_in->buffer_in, sizeof(r_in->buffer_in) ); memcpy( r_out->buffer_in, r_in->buffer_in, sizeof(r_in->buffer_in) );
memcpy( r_out->buffer_out, r_in->buffer_out, sizeof(r_in->buffer_out) ); memcpy( r_out->buffer_out, r_in->buffer_out, sizeof(r_in->buffer_out) );
memcpy( r_out->filter, r_in->filter, sizeof(r_in->filter) );
} }
void resampler_set_quality(void *_r, int quality) void resampler_set_quality(void *_r, int quality)
@ -225,8 +279,7 @@ void resampler_set_quality(void *_r, int quality)
quality = RESAMPLER_QUALITY_MAX; quality = RESAMPLER_QUALITY_MAX;
if ( r->quality != quality ) if ( r->quality != quality )
{ {
if ( quality == RESAMPLER_QUALITY_BLEP || r->quality == RESAMPLER_QUALITY_BLEP || if ( quality == RESAMPLER_QUALITY_BLEP || r->quality == RESAMPLER_QUALITY_BLEP )
quality == RESAMPLER_QUALITY_BLAM || r->quality == RESAMPLER_QUALITY_BLAM )
{ {
r->read_pos = 0; r->read_pos = 0;
r->read_filled = 0; r->read_filled = 0;
@ -236,6 +289,8 @@ void resampler_set_quality(void *_r, int quality)
} }
r->delay_added = -1; r->delay_added = -1;
r->delay_removed = -1; r->delay_removed = -1;
if ( quality == RESAMPLER_QUALITY_BLAM && r->phase_inc )
resampler_set_rate( r, r->phase_inc );
} }
r->quality = (unsigned char)quality; r->quality = (unsigned char)quality;
} }
@ -293,12 +348,12 @@ static int resampler_output_delay(resampler *r)
default: default:
case RESAMPLER_QUALITY_ZOH: case RESAMPLER_QUALITY_ZOH:
case RESAMPLER_QUALITY_LINEAR: case RESAMPLER_QUALITY_LINEAR:
case RESAMPLER_QUALITY_BLAM:
case RESAMPLER_QUALITY_CUBIC: case RESAMPLER_QUALITY_CUBIC:
case RESAMPLER_QUALITY_SINC: case RESAMPLER_QUALITY_SINC:
return 0; return 0;
case RESAMPLER_QUALITY_BLEP: case RESAMPLER_QUALITY_BLEP:
case RESAMPLER_QUALITY_BLAM:
return SINC_WIDTH - 1; return SINC_WIDTH - 1;
} }
} }
@ -326,21 +381,48 @@ void resampler_clear(void *_r)
r->delay_removed = -1; r->delay_removed = -1;
memset(r->buffer_in, 0, (SINC_WIDTH - 1) * sizeof(r->buffer_in[0])); memset(r->buffer_in, 0, (SINC_WIDTH - 1) * sizeof(r->buffer_in[0]));
memset(r->buffer_in + resampler_buffer_size, 0, (SINC_WIDTH - 1) * sizeof(r->buffer_in[0])); memset(r->buffer_in + resampler_buffer_size, 0, (SINC_WIDTH - 1) * sizeof(r->buffer_in[0]));
if (r->quality == RESAMPLER_QUALITY_BLEP || r->quality == RESAMPLER_QUALITY_BLAM) if (r->quality == RESAMPLER_QUALITY_BLEP)
{ {
r->inv_phase = 0; r->inv_phase = 0;
r->last_amp = 0; r->last_amp = 0;
r->accumulator = 0; r->accumulator = 0;
memset(r->buffer_out, 0, sizeof(r->buffer_out)); memset(r->buffer_out, 0, sizeof(r->buffer_out));
} }
if (r->quality == RESAMPLER_QUALITY_BLAM)
{
unsigned int i, j;
for (i = 0, j = IIR_ORDER / 2; i < j; ++i)
iir_clear(r->filter + i);
}
} }
void resampler_set_rate(void *_r, double new_factor) void resampler_set_rate(void *_r, double new_factor)
{ {
resampler * r = ( resampler * ) _r; resampler * r = ( resampler * ) _r;
float old_phase_inc = r->phase_inc;
r->phase_inc = new_factor; r->phase_inc = new_factor;
new_factor = 1.0 / new_factor; new_factor = 1.0 / new_factor;
r->inv_phase_inc = new_factor; r->inv_phase_inc = new_factor;
if (r->quality == RESAMPLER_QUALITY_BLAM && old_phase_inc != r->phase_inc)
{
double ratio_ = new_factor;
unsigned int i, j;
r->output_stage = (ratio_ >= 1.0);
if (!r->output_stage)
{
ratio_ *= 0.45;
}
else
{
ratio_ = (1.0 / ratio_) * 0.45;
}
if (ratio_ > 0.45)
{
ratio_ = 0.45;
}
for (i = 0, j = IIR_ORDER / 2; i < j; ++i)
iir_reset(r->filter + i, ratio_, butterworth(IIR_ORDER, i), 0.0);
}
} }
void resampler_write_sample(void *_r, short s) void resampler_write_sample(void *_r, short s)
@ -355,8 +437,16 @@ void resampler_write_sample(void *_r, short s)
if ( r->write_filled < resampler_buffer_size ) if ( r->write_filled < resampler_buffer_size )
{ {
float s32 = s; double s32 = s;
s32 *= 256.0; s32 *= 256.0;
s32 += 1e-25;
if ( r->quality == RESAMPLER_QUALITY_BLAM && !r->output_stage )
{
unsigned int i, j;
for (i = 0, j = IIR_ORDER / 2; i < j; ++i)
s32 = iir_process(r->filter + i, s32);
}
r->buffer_in[ r->write_pos ] = s32; r->buffer_in[ r->write_pos ] = s32;
r->buffer_in[ r->write_pos + resampler_buffer_size ] = s32; r->buffer_in[ r->write_pos + resampler_buffer_size ] = s32;
@ -379,9 +469,17 @@ void resampler_write_sample_fixed(void *_r, int s, unsigned char depth)
if ( r->write_filled < resampler_buffer_size ) if ( r->write_filled < resampler_buffer_size )
{ {
float s32 = s; double s32 = s;
s32 /= (double)(1 << (depth - 1)); s32 /= (double)(1 << (depth - 1));
s32 += 1e-25;
if ( r->quality == RESAMPLER_QUALITY_BLAM && !r->output_stage )
{
unsigned int i, j;
for (i = 0, j = IIR_ORDER / 2; i < j; ++i)
s32 = iir_process(r->filter + i, s32);
}
r->buffer_in[ r->write_pos ] = s32; r->buffer_in[ r->write_pos ] = s32;
r->buffer_in[ r->write_pos + resampler_buffer_size ] = s32; r->buffer_in[ r->write_pos + resampler_buffer_size ] = s32;
@ -702,11 +800,11 @@ static int resampler_run_linear(resampler * r, float ** out_, float * out_end)
return used; return used;
} }
#ifndef RESAMPLER_NEON
static int resampler_run_blam(resampler * r, float ** out_, float * out_end) static int resampler_run_blam(resampler * r, float ** out_, float * out_end)
{ {
int in_size = r->write_filled; int in_size = r->write_filled;
float const* in_ = r->buffer_in + resampler_buffer_size + r->write_pos - r->write_filled; float const* in_ = r->buffer_in + resampler_buffer_size + r->write_pos - r->write_filled;
unsigned int output_stage = r->output_stage;
int used = 0; int used = 0;
in_size -= 2; in_size -= 2;
if ( in_size > 0 ) if ( in_size > 0 )
@ -714,66 +812,36 @@ static int resampler_run_blam(resampler * r, float ** out_, float * out_end)
float* out = *out_; float* out = *out_;
float const* in = in_; float const* in = in_;
float const* const in_end = in + in_size; float const* const in_end = in + in_size;
float last_amp = r->last_amp;
float phase = r->phase; float phase = r->phase;
float phase_inc = r->phase_inc; float phase_inc = r->phase_inc;
float inv_phase = r->inv_phase;
float inv_phase_inc = r->inv_phase_inc;
const int step = RESAMPLER_BLAM_CUTOFF * RESAMPLER_RESOLUTION;
const int window_step = RESAMPLER_RESOLUTION;
do do
{ {
float sample; float sample;
if ( out + SINC_WIDTH * 2 > out_end ) if ( out >= out_end )
break; break;
sample = in[0]; sample = in[0] + (in[1] - in[0]) * phase;
if (phase_inc < 1.0f)
sample += (in[1] - in[0]) * phase;
sample -= last_amp;
if (sample)
{
float kernel[SINC_WIDTH * 2], kernel_sum = 0.0f;
int phase_reduced = (int)(inv_phase * RESAMPLER_RESOLUTION);
int phase_adj = phase_reduced * step / RESAMPLER_RESOLUTION;
int i = SINC_WIDTH;
for (; i >= -SINC_WIDTH + 1; --i) if ( output_stage )
{ {
int pos = i * step; unsigned int i, j;
int window_pos = i * window_step; for (i = 0, j = IIR_ORDER / 2; i < j; ++i)
kernel_sum += kernel[i + SINC_WIDTH - 1] = sinc_lut[abs(phase_adj - pos)] * window_lut[abs(phase_reduced - window_pos)]; sample = iir_process(r->filter + i, sample);
}
last_amp += sample;
sample /= kernel_sum;
for (i = 0; i < SINC_WIDTH * 2; ++i)
out[i] += sample * kernel[i];
} }
*out++ = sample;
if (inv_phase_inc < 1.0f) phase += phase_inc;
{
++in; in += (int)phase;
inv_phase += inv_phase_inc;
out += (int)inv_phase; phase = fmod(phase, 1.0f);
inv_phase = fmod(inv_phase, 1.0f);
}
else
{
phase += phase_inc;
++out;
in += (int)phase;
phase = fmod(phase, 1.0f);
}
} }
while ( in < in_end ); while ( in < in_end );
r->phase = phase; r->phase = phase;
r->inv_phase = inv_phase;
r->last_amp = last_amp;
*out_ = out; *out_ = out;
used = (int)(in - in_); used = (int)(in - in_);
@ -783,204 +851,6 @@ static int resampler_run_blam(resampler * r, float ** out_, float * out_end)
return used; return used;
} }
#endif
#ifdef RESAMPLER_SSE
static int resampler_run_blam_sse(resampler * r, float ** out_, float * out_end)
{
int in_size = r->write_filled;
float const* in_ = r->buffer_in + resampler_buffer_size + r->write_pos - r->write_filled;
int used = 0;
in_size -= 2;
if ( in_size > 0 )
{
float* out = *out_;
float const* in = in_;
float const* const in_end = in + in_size;
float last_amp = r->last_amp;
float phase = r->phase;
float phase_inc = r->phase_inc;
float inv_phase = r->inv_phase;
float inv_phase_inc = r->inv_phase_inc;
const int step = RESAMPLER_BLAM_CUTOFF * RESAMPLER_RESOLUTION;
const int window_step = RESAMPLER_RESOLUTION;
do
{
float sample;
if ( out + SINC_WIDTH * 2 > out_end )
break;
sample = in[0];
if (phase_inc < 1.0f)
{
sample += (in[1] - in[0]) * phase;
}
sample -= last_amp;
if (sample)
{
float kernel_sum = 0.0f;
__m128 kernel[SINC_WIDTH / 2];
__m128 temp1, temp2;
__m128 samplex;
float *kernelf = (float*)(&kernel);
int phase_reduced = (int)(inv_phase * RESAMPLER_RESOLUTION);
int phase_adj = phase_reduced * step / RESAMPLER_RESOLUTION;
int i = SINC_WIDTH;
for (; i >= -SINC_WIDTH + 1; --i)
{
int pos = i * step;
int window_pos = i * window_step;
kernel_sum += kernelf[i + SINC_WIDTH - 1] = sinc_lut[abs(phase_adj - pos)] * window_lut[abs(phase_reduced - window_pos)];
}
last_amp += sample;
sample /= kernel_sum;
samplex = _mm_set1_ps( sample );
for (i = 0; i < SINC_WIDTH / 2; ++i)
{
temp1 = _mm_load_ps( (const float *)( kernel + i ) );
temp1 = _mm_mul_ps( temp1, samplex );
temp2 = _mm_loadu_ps( (const float *) out + i * 4 );
temp1 = _mm_add_ps( temp1, temp2 );
_mm_storeu_ps( (float *) out + i * 4, temp1 );
}
}
if (inv_phase_inc < 1.0f)
{
++in;
inv_phase += inv_phase_inc;
out += (int)inv_phase;
inv_phase = fmod(inv_phase, 1.0f);
}
else
{
phase += phase_inc;
++out;
if (phase >= 1.0f)
{
++in;
phase = fmod(phase, 1.0f);
}
}
}
while ( in < in_end );
r->phase = phase;
r->inv_phase = inv_phase;
r->last_amp = last_amp;
*out_ = out;
used = (int)(in - in_);
r->write_filled -= used;
}
return used;
}
#endif
#ifdef RESAMPLER_NEON
static int resampler_run_blam(resampler * r, float ** out_, float * out_end)
{
int in_size = r->write_filled;
float const* in_ = r->buffer_in + resampler_buffer_size + r->write_pos - r->write_filled;
int used = 0;
in_size -= 2;
if ( in_size > 0 )
{
float* out = *out_;
float const* in = in_;
float const* const in_end = in + in_size;
float last_amp = r->last_amp;
float phase = r->phase;
float phase_inc = r->phase_inc;
float inv_phase = r->inv_phase;
float inv_phase_inc = r->inv_phase_inc;
const int step = RESAMPLER_BLAM_CUTOFF * RESAMPLER_RESOLUTION;
const int window_step = RESAMPLER_RESOLUTION;
do
{
float sample;
if ( out + SINC_WIDTH * 2 > out_end )
break;
sample = in[0];
if (phase_inc < 1.0f)
sample += (in[1] - in[0]) * phase;
sample -= last_amp;
if (sample)
{
float kernel_sum = 0.0;
float32x4_t kernel[SINC_WIDTH / 2];
float32x4_t temp1, temp2;
float32x4_t samplex;
float *kernelf = (float*)(&kernel);
int phase_reduced = (int)(inv_phase * RESAMPLER_RESOLUTION);
int phase_adj = phase_reduced * step / RESAMPLER_RESOLUTION;
int i = SINC_WIDTH;
for (; i >= -SINC_WIDTH + 1; --i)
{
int pos = i * step;
int window_pos = i * window_step;
kernel_sum += kernelf[i + SINC_WIDTH - 1] = sinc_lut[abs(phase_adj - pos)] * window_lut[abs(phase_reduced - window_pos)];
}
last_amp += sample;
sample /= kernel_sum;
samplex = vdupq_n_f32(sample);
for (i = 0; i < SINC_WIDTH / 2; ++i)
{
temp1 = vld1q_f32( (const float32_t *)( kernel + i ) );
temp2 = vld1q_f32( (const float32_t *) out + i * 4 );
temp2 = vmlaq_f32( temp2, temp1, samplex );
vst1q_f32( (float32_t *) out + i * 4, temp2 );
}
}
if (inv_phase_inc < 1.0f)
{
++in;
inv_phase += inv_phase_inc;
out += (int)inv_phase;
inv_phase = fmod(inv_phase, 1.0f);
}
else
{
phase += phase_inc;
++out;
if (phase >= 1.0f)
{
++in;
phase = fmod(phase, 1.0f);
}
}
}
while ( in < in_end );
r->phase = phase;
r->inv_phase = inv_phase;
r->last_amp = last_amp;
*out_ = out;
used = (int)(in - in_);
r->write_filled -= used;
}
return used;
}
#endif
#ifndef RESAMPLER_NEON #ifndef RESAMPLER_NEON
static int resampler_run_cubic(resampler * r, float ** out_, float * out_end) static int resampler_run_cubic(resampler * r, float ** out_, float * out_end)
@ -1387,25 +1257,8 @@ static void resampler_fill(resampler * r)
break; break;
case RESAMPLER_QUALITY_BLAM: case RESAMPLER_QUALITY_BLAM:
{ resampler_run_blam( r, &out, out + write_size );
float * out_ = out;
int write_extra = 0;
if ( write_pos >= r->read_pos )
write_extra = r->read_pos;
if ( write_extra > SINC_WIDTH * 2 - 1 )
write_extra = SINC_WIDTH * 2 - 1;
memcpy( r->buffer_out + resampler_buffer_size, r->buffer_out, write_extra * sizeof(r->buffer_out[0]) );
#ifdef RESAMPLER_SSE
if ( resampler_has_sse )
resampler_run_blam_sse( r, &out, out + write_size + write_extra );
else
#endif
resampler_run_blam( r, &out, out + write_size + write_extra );
memcpy( r->buffer_out, r->buffer_out + resampler_buffer_size, write_extra * sizeof(r->buffer_out[0]) );
if ( out == out_ )
return;
break; break;
}
case RESAMPLER_QUALITY_CUBIC: case RESAMPLER_QUALITY_CUBIC:
#ifdef RESAMPLER_SSE #ifdef RESAMPLER_SSE
@ -1444,7 +1297,7 @@ static void resampler_fill_and_remove_delay(resampler * r)
int resampler_get_sample_count(void *_r) int resampler_get_sample_count(void *_r)
{ {
resampler * r = ( resampler * ) _r; resampler * r = ( resampler * ) _r;
if ( r->read_filled < 1 && ((r->quality != RESAMPLER_QUALITY_BLEP && r->quality != RESAMPLER_QUALITY_BLAM) || r->inv_phase_inc)) if ( r->read_filled < 1 && (r->quality != RESAMPLER_QUALITY_BLEP || r->inv_phase_inc) )
resampler_fill_and_remove_delay( r ); resampler_fill_and_remove_delay( r );
return r->read_filled; return r->read_filled;
} }
@ -1456,7 +1309,7 @@ int resampler_get_sample(void *_r)
resampler_fill_and_remove_delay( r ); resampler_fill_and_remove_delay( r );
if ( r->read_filled < 1 ) if ( r->read_filled < 1 )
return 0; return 0;
if ( r->quality == RESAMPLER_QUALITY_BLEP || r->quality == RESAMPLER_QUALITY_BLAM ) if ( r->quality == RESAMPLER_QUALITY_BLEP )
return (int)(r->buffer_out[ r->read_pos ] + r->accumulator); return (int)(r->buffer_out[ r->read_pos ] + r->accumulator);
else else
return (int)r->buffer_out[ r->read_pos ]; return (int)r->buffer_out[ r->read_pos ];
@ -1469,7 +1322,7 @@ float resampler_get_sample_float(void *_r)
resampler_fill_and_remove_delay( r ); resampler_fill_and_remove_delay( r );
if ( r->read_filled < 1 ) if ( r->read_filled < 1 )
return 0; return 0;
if ( r->quality == RESAMPLER_QUALITY_BLEP || r->quality == RESAMPLER_QUALITY_BLAM ) if ( r->quality == RESAMPLER_QUALITY_BLEP )
return r->buffer_out[ r->read_pos ] + r->accumulator; return r->buffer_out[ r->read_pos ] + r->accumulator;
else else
return r->buffer_out[ r->read_pos ]; return r->buffer_out[ r->read_pos ];
@ -1480,7 +1333,7 @@ void resampler_remove_sample(void *_r, int decay)
resampler * r = ( resampler * ) _r; resampler * r = ( resampler * ) _r;
if ( r->read_filled > 0 ) if ( r->read_filled > 0 )
{ {
if ( r->quality == RESAMPLER_QUALITY_BLEP || r->quality == RESAMPLER_QUALITY_BLAM ) if ( r->quality == RESAMPLER_QUALITY_BLEP )
{ {
r->accumulator += r->buffer_out[ r->read_pos ]; r->accumulator += r->buffer_out[ r->read_pos ];
r->buffer_out[ r->read_pos ] = 0; r->buffer_out[ r->read_pos ] = 0;