ref: 2c21da52cbd096f3d7409b58b47d8cddcad6b84b
parent: 9aa0dc277e1360b918aa62f87c92841f25f141ab
author: Chris Moeller <kode54@gmail.com>
date: Sun May 11 13:29:13 EDT 2014
Increased precision of resampler phase variable, greatly reducing the incidence of sample rate rounding errors
--- a/dumb/include/internal/resampler.h
+++ b/dumb/include/internal/resampler.h
@@ -13,11 +13,13 @@
#define resampler_set_quality EVALUATE(RESAMPLER_DECORATE,_resampler_set_quality)
#define resampler_get_free_count EVALUATE(RESAMPLER_DECORATE,_resampler_get_free_count)
#define resampler_write_sample EVALUATE(RESAMPLER_DECORATE,_resampler_write_sample)
+#define resampler_write_sample_fixed EVALUATE(RESAMPLER_DECORATE,_resampler_write_sample_fixed)
#define resampler_set_rate EVALUATE(RESAMPLER_DECORATE,_resampler_set_rate)
#define resampler_ready EVALUATE(RESAMPLER_DECORATE,_resampler_ready)
#define resampler_clear EVALUATE(RESAMPLER_DECORATE,_resampler_clear)
#define resampler_get_sample_count EVALUATE(RESAMPLER_DECORATE,_resampler_get_sample_count)
#define resampler_get_sample EVALUATE(RESAMPLER_DECORATE,_resampler_get_sample)
+#define resampler_get_sample_float EVALUATE(RESAMPLER_DECORATE,_resampler_get_sample_float)
#define resampler_remove_sample EVALUATE(RESAMPLER_DECORATE,_resampler_remove_sample)
#endif
@@ -43,11 +45,13 @@
int resampler_get_free_count(void *);
void resampler_write_sample(void *, short sample);
+void resampler_write_sample_fixed(void *, int sample, unsigned char depth);
void resampler_set_rate( void *, double new_factor );
int resampler_ready(void *);
void resampler_clear(void *);
int resampler_get_sample_count(void *);
int resampler_get_sample(void *);
+float resampler_get_sample_float(void *);
void resampler_remove_sample(void *);
#endif
--- a/dumb/src/helpers/resampler.c
+++ b/dumb/src/helpers/resampler.c
@@ -20,7 +20,9 @@
#include "internal/resampler.h"
enum { RESAMPLER_SHIFT = 10 };
+enum { RESAMPLER_SHIFT_EXTRA = 8 };
enum { RESAMPLER_RESOLUTION = 1 << RESAMPLER_SHIFT };
+enum { RESAMPLER_RESOLUTION_EXTRA = 1 << (RESAMPLER_SHIFT + RESAMPLER_SHIFT_EXTRA) };
enum { SINC_WIDTH = 16 };
enum { SINC_SAMPLES = RESAMPLER_RESOLUTION * SINC_WIDTH };
enum { CUBIC_SAMPLES = RESAMPLER_RESOLUTION * 4 };
@@ -324,9 +326,9 @@
void resampler_set_rate(void *_r, double new_factor)
{
resampler * r = ( resampler * ) _r;
- r->phase_inc = (int)( new_factor * RESAMPLER_RESOLUTION );
+ r->phase_inc = (int)( new_factor * RESAMPLER_RESOLUTION_EXTRA );
new_factor = 1.0 / new_factor;
- r->inv_phase_inc = (int)( new_factor * RESAMPLER_RESOLUTION );
+ r->inv_phase_inc = (int)( new_factor * RESAMPLER_RESOLUTION_EXTRA );
}
void resampler_write_sample(void *_r, short s)
@@ -403,13 +405,13 @@
phase += phase_inc;
- in += phase >> RESAMPLER_SHIFT;
+ in += phase >> (RESAMPLER_SHIFT + RESAMPLER_SHIFT_EXTRA);
- phase &= RESAMPLER_RESOLUTION-1;
+ phase &= RESAMPLER_RESOLUTION_EXTRA - 1;
}
while ( in < in_end );
- r->phase = (unsigned short) phase;
+ r->phase = phase;
*out_ = out;
used = (int)(in - in_);
@@ -440,6 +442,7 @@
do
{
float kernel[SINC_WIDTH * 2], kernel_sum = 0.0;
+ int phase_reduced = inv_phase >> RESAMPLER_SHIFT_EXTRA;
int i = SINC_WIDTH;
float sample;
@@ -449,7 +452,7 @@
for (; i >= -SINC_WIDTH + 1; --i)
{
int pos = i * step;
- int abs_pos = abs(inv_phase - pos);
+ int abs_pos = abs(phase_reduced - pos);
kernel_sum += kernel[i + SINC_WIDTH - 1] = sinc_lut[abs_pos] * window_lut[abs_pos];
}
sample = *in++ - last_amp;
@@ -460,9 +463,9 @@
inv_phase += inv_phase_inc;
- out += inv_phase >> RESAMPLER_SHIFT;
+ out += inv_phase >> (RESAMPLER_SHIFT + RESAMPLER_SHIFT_EXTRA);
- inv_phase &= RESAMPLER_RESOLUTION-1;
+ inv_phase &= RESAMPLER_RESOLUTION_EXTRA - 1;
}
while ( in < in_end );
@@ -505,6 +508,7 @@
__m128 samplex;
float sample;
float *kernelf = (float*)(&kernel);
+ int phase_reduced = inv_phase >> RESAMPLER_SHIFT_EXTRA;
int i = SINC_WIDTH;
if ( out + SINC_WIDTH * 2 > out_end )
@@ -513,7 +517,7 @@
for (; i >= -SINC_WIDTH + 1; --i)
{
int pos = i * step;
- int abs_pos = abs(inv_phase - pos);
+ int abs_pos = abs(phase_reduced - pos);
kernel_sum += kernelf[i + SINC_WIDTH - 1] = sinc_lut[abs_pos] * window_lut[abs_pos];
}
sample = *in++ - last_amp;
@@ -531,9 +535,9 @@
inv_phase += inv_phase_inc;
- out += inv_phase >> RESAMPLER_SHIFT;
+ out += inv_phase >> (RESAMPLER_SHIFT + RESAMPLER_SHIFT_EXTRA);
- inv_phase &= RESAMPLER_RESOLUTION - 1;
+ inv_phase &= RESAMPLER_RESOLUTION_EXTRA - 1;
}
while ( in < in_end );
@@ -571,14 +575,14 @@
if ( out >= out_end )
break;
- sample = in[0] + (in[1] - in[0]) * ((float)phase / RESAMPLER_RESOLUTION);
+ sample = in[0] + (in[1] - in[0]) * ((float)phase / RESAMPLER_RESOLUTION_EXTRA);
*out++ = sample;
phase += phase_inc;
- in += phase >> RESAMPLER_SHIFT;
+ in += phase >> (RESAMPLER_SHIFT + RESAMPLER_SHIFT_EXTRA);
- phase &= RESAMPLER_RESOLUTION-1;
+ phase &= RESAMPLER_RESOLUTION_EXTRA - 1;
}
while ( in < in_end );
@@ -616,7 +620,7 @@
if ( out >= out_end )
break;
- kernel = cubic_lut + phase * 4;
+ kernel = cubic_lut + (phase >> RESAMPLER_SHIFT_EXTRA) * 4;
for (sample = 0, i = 0; i < 4; ++i)
sample += in[i] * kernel[i];
@@ -624,9 +628,9 @@
phase += phase_inc;
- in += phase >> RESAMPLER_SHIFT;
+ in += phase >> (RESAMPLER_SHIFT + RESAMPLER_SHIFT_EXTRA);
- phase &= RESAMPLER_RESOLUTION-1;
+ phase &= RESAMPLER_RESOLUTION_EXTRA - 1;
}
while ( in < in_end );
@@ -665,7 +669,7 @@
break;
temp1 = _mm_loadu_ps( (const float *)( in ) );
- temp2 = _mm_load_ps( (const float *)( cubic_lut + phase * 4 ) );
+ temp2 = _mm_load_ps( (const float *)( cubic_lut + (phase >> RESAMPLER_SHIFT_EXTRA) * 4 ) );
temp1 = _mm_mul_ps( temp1, temp2 );
samplex = _mm_add_ps( samplex, temp1 );
temp1 = _mm_movehl_ps( temp1, samplex );
@@ -678,9 +682,9 @@
phase += phase_inc;
- in += phase >> RESAMPLER_SHIFT;
+ in += phase >> (RESAMPLER_SHIFT + RESAMPLER_SHIFT_EXTRA);
- phase &= RESAMPLER_RESOLUTION - 1;
+ phase &= RESAMPLER_RESOLUTION_EXTRA - 1;
}
while ( in < in_end );
@@ -710,7 +714,7 @@
int phase = r->phase;
int phase_inc = r->phase_inc;
- int step = phase_inc > RESAMPLER_RESOLUTION ? RESAMPLER_RESOLUTION * RESAMPLER_RESOLUTION / phase_inc : RESAMPLER_RESOLUTION;
+ int step = phase_inc > RESAMPLER_RESOLUTION_EXTRA ? RESAMPLER_RESOLUTION * RESAMPLER_RESOLUTION_EXTRA / phase_inc : RESAMPLER_RESOLUTION;
int window_step = RESAMPLER_RESOLUTION;
do
@@ -717,7 +721,8 @@
{
float kernel[SINC_WIDTH * 2], kernel_sum = 0.0;
int i = SINC_WIDTH;
- int phase_adj = phase * step / RESAMPLER_RESOLUTION;
+ int phase_reduced = phase >> RESAMPLER_SHIFT_EXTRA;
+ int phase_adj = phase_reduced * step / RESAMPLER_RESOLUTION;
float sample;
if ( out >= out_end )
@@ -727,7 +732,7 @@
{
int pos = i * step;
int window_pos = i * window_step;
- kernel_sum += kernel[i + SINC_WIDTH - 1] = sinc_lut[abs(phase_adj - pos)] * window_lut[abs(phase - window_pos)];
+ kernel_sum += kernel[i + SINC_WIDTH - 1] = sinc_lut[abs(phase_adj - pos)] * window_lut[abs(phase_reduced - window_pos)];
}
for (sample = 0, i = 0; i < SINC_WIDTH * 2; ++i)
sample += in[i] * kernel[i];
@@ -735,9 +740,9 @@
phase += phase_inc;
- in += phase >> RESAMPLER_SHIFT;
+ in += phase >> (RESAMPLER_SHIFT + RESAMPLER_SHIFT_EXTRA);
- phase &= RESAMPLER_RESOLUTION-1;
+ phase &= RESAMPLER_RESOLUTION_EXTRA - 1;
}
while ( in < in_end );
@@ -767,7 +772,7 @@
int phase = r->phase;
int phase_inc = r->phase_inc;
- int step = phase_inc > RESAMPLER_RESOLUTION ? RESAMPLER_RESOLUTION * RESAMPLER_RESOLUTION / phase_inc : RESAMPLER_RESOLUTION;
+ int step = phase_inc > RESAMPLER_RESOLUTION_EXTRA ? RESAMPLER_RESOLUTION * RESAMPLER_RESOLUTION_EXTRA / phase_inc : RESAMPLER_RESOLUTION;
int window_step = RESAMPLER_RESOLUTION;
do
@@ -779,7 +784,8 @@
__m128 samplex = _mm_setzero_ps();
float *kernelf = (float*)(&kernel);
int i = SINC_WIDTH;
- int phase_adj = phase * step / RESAMPLER_RESOLUTION;
+ int phase_reduced = phase >> RESAMPLER_SHIFT_EXTRA;
+ int phase_adj = phase_reduced * step / RESAMPLER_RESOLUTION;
if ( out >= out_end )
break;
@@ -788,7 +794,7 @@
{
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 - window_pos)];
+ kernel_sum += kernelf[i + SINC_WIDTH - 1] = sinc_lut[abs(phase_adj - pos)] * window_lut[abs(phase_reduced - window_pos)];
}
for (i = 0; i < SINC_WIDTH / 2; ++i)
{
@@ -810,9 +816,9 @@
phase += phase_inc;
- in += phase >> RESAMPLER_SHIFT;
+ in += phase >> (RESAMPLER_SHIFT + RESAMPLER_SHIFT_EXTRA);
- phase &= RESAMPLER_RESOLUTION - 1;
+ phase &= RESAMPLER_RESOLUTION_EXTRA - 1;
}
while ( in < in_end );
@@ -922,6 +928,19 @@
return (int)(r->buffer_out[ r->read_pos ] + r->accumulator);
else
return (int)r->buffer_out[ r->read_pos ];
+}
+
+float resampler_get_sample_float(void *_r)
+{
+ resampler * r = ( resampler * ) _r;
+ if ( r->read_filled < 1 && r->phase_inc)
+ resampler_fill_and_remove_delay( r );
+ if ( r->read_filled < 1 )
+ return 0;
+ if ( r->quality == RESAMPLER_QUALITY_BLEP )
+ return r->buffer_out[ r->read_pos ] + r->accumulator;
+ else
+ return r->buffer_out[ r->read_pos ];
}
void resampler_remove_sample(void *_r)