chris/Cog
2
1
Fork 0
Code Issues 65 Pull requests Projects Releases Packages Wiki Activity Actions

Changed sinc window to Nuttal 3 term, and added silence pre-fill to account for the window delay

Browse source
This commit is contained in:
Chris Moeller 2014-03-23 21:05:58 -07:00
parent 46815ba392
commit 9aae7b9c41
2 changed files with 21 additions and 11 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

17
Frameworks/Dumb/dumb/src/helpers/resampler.c
View file

@ -17,7 +17,7 @@
#define M_PI 3.14159265358979323846 #define M_PI 3.14159265358979323846
#endif #endif
#include "resampler.h" #include "internal/resampler.h"
enum { RESAMPLER_SHIFT = 13 }; enum { RESAMPLER_SHIFT = 13 };
enum { RESAMPLER_RESOLUTION = 1 << RESAMPLER_SHIFT }; enum { RESAMPLER_RESOLUTION = 1 << RESAMPLER_SHIFT };
@ -76,9 +76,12 @@ void resampler_init(void)
for (i = 0; i < SINC_SAMPLES + 1; ++i, x += dx) for (i = 0; i < SINC_SAMPLES + 1; ++i, x += dx)
{ {
float y = x / SINC_WIDTH; float y = x / SINC_WIDTH;
#if 1 #if 0
// Blackman // Blackman
float window = 0.42659 - 0.49656 * cos(M_PI + M_PI * y) + 0.076849 * cos(2.0 * M_PI * y); float window = 0.42659 - 0.49656 * cos(M_PI + M_PI * y) + 0.076849 * cos(2.0 * M_PI * y);
#elif 1
// Nuttal 3 term
float window = 0.40897 + 0.5 * cos(M_PI * y) + 0.09103 * cos(2.0 * M_PI * y);
#elif 0 #elif 0
// C.R.Helmrich's 2 term window // C.R.Helmrich's 2 term window
float window = 0.79445 * cos(0.5 * M_PI * y) + 0.20555 * cos(1.5 * M_PI * y); float window = 0.79445 * cos(0.5 * M_PI * y) + 0.20555 * cos(1.5 * M_PI * y);
@ -118,8 +121,8 @@ void * resampler_create(void)
resampler * r = ( resampler * ) malloc( sizeof(resampler) ); resampler * r = ( resampler * ) malloc( sizeof(resampler) );
if ( !r ) return 0; if ( !r ) return 0;
r->write_pos = 0; r->write_pos = SINC_WIDTH - 1;
r->write_filled = 0; r->write_filled = SINC_WIDTH - 1;
r->read_pos = 0; r->read_pos = 0;
r->read_filled = 0; r->read_filled = 0;
r->phase = 0; r->phase = 0;
@ -215,11 +218,13 @@ int resampler_ready(void *_r)
void resampler_clear(void *_r) void resampler_clear(void *_r)
{ {
resampler * r = ( resampler * ) _r; resampler * r = ( resampler * ) _r;
r->write_pos = 0; r->write_pos = SINC_WIDTH - 1;
r->write_filled = 0; r->write_filled = SINC_WIDTH - 1;
r->read_pos = 0; r->read_pos = 0;
r->read_filled = 0; r->read_filled = 0;
r->phase = 0; r->phase = 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]));
} }
void resampler_set_rate(void *_r, double new_factor) void resampler_set_rate(void *_r, double new_factor)

15
Frameworks/modplay/modplay/resampler.c
View file

@ -76,9 +76,12 @@ void resampler_init(void)
for (i = 0; i < SINC_SAMPLES + 1; ++i, x += dx) for (i = 0; i < SINC_SAMPLES + 1; ++i, x += dx)
{ {
float y = x / SINC_WIDTH; float y = x / SINC_WIDTH;
#if 1 #if 0
// Blackman // Blackman
float window = 0.42659 - 0.49656 * cos(M_PI + M_PI * y) + 0.076849 * cos(2.0 * M_PI * y); float window = 0.42659 - 0.49656 * cos(M_PI + M_PI * y) + 0.076849 * cos(2.0 * M_PI * y);
#elif 1
// Nuttal 3 term
float window = 0.40897 + 0.5 * cos(M_PI * y) + 0.09103 * cos(2.0 * M_PI * y);
#elif 0 #elif 0
// C.R.Helmrich's 2 term window // C.R.Helmrich's 2 term window
float window = 0.79445 * cos(0.5 * M_PI * y) + 0.20555 * cos(1.5 * M_PI * y); float window = 0.79445 * cos(0.5 * M_PI * y) + 0.20555 * cos(1.5 * M_PI * y);
@ -118,8 +121,8 @@ void * resampler_create(void)
resampler * r = ( resampler * ) malloc( sizeof(resampler) ); resampler * r = ( resampler * ) malloc( sizeof(resampler) );
if ( !r ) return 0; if ( !r ) return 0;
r->write_pos = 0; r->write_pos = SINC_WIDTH - 1;
r->write_filled = 0; r->write_filled = SINC_WIDTH - 1;
r->read_pos = 0; r->read_pos = 0;
r->read_filled = 0; r->read_filled = 0;
r->phase = 0; r->phase = 0;
@ -215,11 +218,13 @@ int resampler_ready(void *_r)
void resampler_clear(void *_r) void resampler_clear(void *_r)
{ {
resampler * r = ( resampler * ) _r; resampler * r = ( resampler * ) _r;
r->write_pos = 0; r->write_pos = SINC_WIDTH - 1;
r->write_filled = 0; r->write_filled = SINC_WIDTH - 1;
r->read_pos = 0; r->read_pos = 0;
r->read_filled = 0; r->read_filled = 0;
r->phase = 0; r->phase = 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]));
} }
void resampler_set_rate(void *_r, double new_factor) void resampler_set_rate(void *_r, double new_factor)