DUMB and modplay resampler now adds input delay and subtracts output delay according to whichever quality is selected, rather than being fixed for sinc only. This fixes blep synthesis mode defeating note on and off volume ramping.

Frameworks/Dumb/dumb/src/helpers/resampler.c

@@ -17,7 +17,7 @@
 #define M_PI 3.14159265358979323846
 #endif
 
-#include "internal/resampler.h"
+#include "resampler.h"
 
 enum { RESAMPLER_SHIFT = 13 };
 enum { RESAMPLER_RESOLUTION = 1 << RESAMPLER_SHIFT };
@@ -114,6 +114,8 @@ typedef struct resampler
     unsigned int inv_phase;
     unsigned int inv_phase_inc;
     unsigned char quality;
+    signed char delay_added;
+    signed char delay_removed;
     float last_amp;
     float accumulator;
     float buffer_in[resampler_buffer_size * 2];
@@ -126,7 +128,7 @@ void * resampler_create(void)
     if ( !r ) return 0;
 
     r->write_pos = SINC_WIDTH - 1;
-    r->write_filled = SINC_WIDTH - 1;
+    r->write_filled = 0;
     r->read_pos = 0;
     r->read_filled = 0;
     r->phase = 0;
@@ -134,6 +136,8 @@ void * resampler_create(void)
     r->inv_phase = 0;
     r->inv_phase_inc = 0;
     r->quality = RESAMPLER_QUALITY_MAX;
+    r->delay_added = -1;
+    r->delay_removed = -1;
     r->last_amp = 0;
     r->accumulator = 0;
     memset( r->buffer_in, 0, sizeof(r->buffer_in) );
@@ -162,6 +166,8 @@ void * resampler_dup(const void * _r)
     r_out->inv_phase = r_in->inv_phase;
     r_out->inv_phase_inc = r_in->inv_phase_inc;
     r_out->quality = r_in->quality;
+    r_out->delay_added = r_in->delay_added;
+    r_out->delay_removed = r_in->delay_removed;
     r_out->last_amp = r_in->last_amp;
     r_out->accumulator = r_in->accumulator;
     memcpy( r_out->buffer_in, r_in->buffer_in, sizeof(r_in->buffer_in) );
@@ -184,6 +190,8 @@ void resampler_dup_inplace(void *_d, const void *_s)
     r_out->inv_phase = r_in->inv_phase;
     r_out->inv_phase_inc = r_in->inv_phase_inc;
     r_out->quality = r_in->quality;
+    r_out->delay_added = r_in->delay_added;
+    r_out->delay_removed = r_in->delay_removed;
     r_out->last_amp = r_in->last_amp;
     r_out->accumulator = r_in->accumulator;
     memcpy( r_out->buffer_in, r_in->buffer_in, sizeof(r_in->buffer_in) );
@@ -207,6 +215,8 @@ void resampler_set_quality(void *_r, int quality)
             r->accumulator = 0;
             memset( r->buffer_out, 0, sizeof(r->buffer_out) );
         }
+        r->delay_added = -1;
+        r->delay_removed = -1;
     }
     r->quality = (unsigned char)quality;
 }
@@ -237,6 +247,40 @@ static int resampler_min_filled(resampler *r)
     }
 }
 
+static int resampler_input_delay(resampler *r)
+{
+    switch (r->quality)
+    {
+    default:
+    case RESAMPLER_QUALITY_ZOH:
+    case RESAMPLER_QUALITY_BLEP:
+    case RESAMPLER_QUALITY_LINEAR:
+        return 0;
+            
+    case RESAMPLER_QUALITY_CUBIC:
+        return 1;
+            
+    case RESAMPLER_QUALITY_SINC:
+        return SINC_WIDTH - 1;
+    }
+}
+
+static int resampler_output_delay(resampler *r)
+{
+    switch (r->quality)
+    {
+    default:
+    case RESAMPLER_QUALITY_ZOH:
+    case RESAMPLER_QUALITY_LINEAR:
+    case RESAMPLER_QUALITY_CUBIC:
+    case RESAMPLER_QUALITY_SINC:
+        return 0;
+            
+    case RESAMPLER_QUALITY_BLEP:
+        return SINC_WIDTH - 1;
+    }
+}
+
 int resampler_ready(void *_r)
 {
     resampler * r = ( resampler * ) _r;
@@ -247,10 +291,12 @@ void resampler_clear(void *_r)
 {
     resampler * r = ( resampler * ) _r;
     r->write_pos = SINC_WIDTH - 1;
-    r->write_filled = SINC_WIDTH - 1;
+    r->write_filled = 0;
     r->read_pos = 0;
     r->read_filled = 0;
     r->phase = 0;
+    r->delay_added = -1;
+    r->delay_removed = -1;
     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]));
     if (r->quality == RESAMPLER_QUALITY_BLEP)
@@ -269,10 +315,16 @@ void resampler_write_sample(void *_r, short s)
 {
     resampler * r = ( resampler * ) _r;
 
+    if ( r->delay_added < 0 )
+    {
+        r->delay_added = 0;
+        r->write_filled = resampler_input_delay( r );
+    }
+    
     if ( r->write_filled < resampler_buffer_size )
     {
         float s32 = s;
-        s32 *= (1.0 / 32768.0);
+        s32 *= 256.0;
 
         r->buffer_in[ r->write_pos ] = s32;
         r->buffer_in[ r->write_pos + resampler_buffer_size ] = s32;
@@ -791,11 +843,23 @@ static void resampler_fill(resampler * r)
     }
 }
 
+static void resampler_fill_and_remove_delay(resampler * r)
+{
+    resampler_fill( r );
+    if ( r->delay_removed < 0 )
+    {
+        int delay = resampler_output_delay( r );
+        r->delay_removed = 0;
+        while ( delay-- )
+            resampler_remove_sample( r );
+    }
+}
+
 int resampler_get_sample_count(void *_r)
 {
     resampler * r = ( resampler * ) _r;
-    if ( r->read_filled < 1 )
+    if ( r->read_filled < 1 && (r->quality != RESAMPLER_QUALITY_BLEP || r->inv_phase_inc))
-        resampler_fill( r );
+        resampler_fill_and_remove_delay( r );
     return r->read_filled;
 }
 
@@ -803,13 +867,13 @@ int resampler_get_sample(void *_r)
 {
     resampler * r = ( resampler * ) _r;
     if ( r->read_filled < 1 && r->phase_inc)
-        resampler_fill( r );
+        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) * 8388608.0;
+        return (int)(r->buffer_out[ r->read_pos ] + r->accumulator);
     else
-        return r->buffer_out[ r->read_pos ] * 8388608.0;
+        return (int)r->buffer_out[ r->read_pos ];
 }
 
 void resampler_remove_sample(void *_r)
@@ -822,6 +886,8 @@ void resampler_remove_sample(void *_r)
             r->accumulator += r->buffer_out[ r->read_pos ];
             r->buffer_out[ r->read_pos ] = 0;
             r->accumulator -= r->accumulator * (1.0 / 8192.0);
+            if (fabs(r->accumulator) < 1e-20)
+                r->accumulator = 0;
         }
         --r->read_filled;
         r->read_pos = ( r->read_pos + 1 ) % resampler_buffer_size;

Frameworks/modplay/modplay/resampler.c

@@ -114,6 +114,8 @@ typedef struct resampler
     unsigned int inv_phase;
     unsigned int inv_phase_inc;
     unsigned char quality;
+    signed char delay_added;
+    signed char delay_removed;
     float last_amp;
     float accumulator;
     float buffer_in[resampler_buffer_size * 2];
@@ -126,7 +128,7 @@ void * resampler_create(void)
     if ( !r ) return 0;
 
     r->write_pos = SINC_WIDTH - 1;
-    r->write_filled = SINC_WIDTH - 1;
+    r->write_filled = 0;
     r->read_pos = 0;
     r->read_filled = 0;
     r->phase = 0;
@@ -134,6 +136,8 @@ void * resampler_create(void)
     r->inv_phase = 0;
     r->inv_phase_inc = 0;
     r->quality = RESAMPLER_QUALITY_MAX;
+    r->delay_added = -1;
+    r->delay_removed = -1;
     r->last_amp = 0;
     r->accumulator = 0;
     memset( r->buffer_in, 0, sizeof(r->buffer_in) );
@@ -162,6 +166,8 @@ void * resampler_dup(const void * _r)
     r_out->inv_phase = r_in->inv_phase;
     r_out->inv_phase_inc = r_in->inv_phase_inc;
     r_out->quality = r_in->quality;
+    r_out->delay_added = r_in->delay_added;
+    r_out->delay_removed = r_in->delay_removed;
     r_out->last_amp = r_in->last_amp;
     r_out->accumulator = r_in->accumulator;
     memcpy( r_out->buffer_in, r_in->buffer_in, sizeof(r_in->buffer_in) );
@@ -184,6 +190,8 @@ void resampler_dup_inplace(void *_d, const void *_s)
     r_out->inv_phase = r_in->inv_phase;
     r_out->inv_phase_inc = r_in->inv_phase_inc;
     r_out->quality = r_in->quality;
+    r_out->delay_added = r_in->delay_added;
+    r_out->delay_removed = r_in->delay_removed;
     r_out->last_amp = r_in->last_amp;
     r_out->accumulator = r_in->accumulator;
     memcpy( r_out->buffer_in, r_in->buffer_in, sizeof(r_in->buffer_in) );
@@ -207,6 +215,8 @@ void resampler_set_quality(void *_r, int quality)
             r->accumulator = 0;
             memset( r->buffer_out, 0, sizeof(r->buffer_out) );
         }
+        r->delay_added = -1;
+        r->delay_removed = -1;
     }
     r->quality = (unsigned char)quality;
 }
@@ -237,6 +247,40 @@ static int resampler_min_filled(resampler *r)
     }
 }
 
+static int resampler_input_delay(resampler *r)
+{
+    switch (r->quality)
+    {
+    default:
+    case RESAMPLER_QUALITY_ZOH:
+    case RESAMPLER_QUALITY_BLEP:
+    case RESAMPLER_QUALITY_LINEAR:
+        return 0;
+            
+    case RESAMPLER_QUALITY_CUBIC:
+        return 1;
+            
+    case RESAMPLER_QUALITY_SINC:
+        return SINC_WIDTH - 1;
+    }
+}
+
+static int resampler_output_delay(resampler *r)
+{
+    switch (r->quality)
+    {
+    default:
+    case RESAMPLER_QUALITY_ZOH:
+    case RESAMPLER_QUALITY_LINEAR:
+    case RESAMPLER_QUALITY_CUBIC:
+    case RESAMPLER_QUALITY_SINC:
+        return 0;
+            
+    case RESAMPLER_QUALITY_BLEP:
+        return SINC_WIDTH - 1;
+    }
+}
+
 int resampler_ready(void *_r)
 {
     resampler * r = ( resampler * ) _r;
@@ -247,10 +291,12 @@ void resampler_clear(void *_r)
 {
     resampler * r = ( resampler * ) _r;
     r->write_pos = SINC_WIDTH - 1;
-    r->write_filled = SINC_WIDTH - 1;
+    r->write_filled = 0;
     r->read_pos = 0;
     r->read_filled = 0;
     r->phase = 0;
+    r->delay_added = -1;
+    r->delay_removed = -1;
     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]));
     if (r->quality == RESAMPLER_QUALITY_BLEP)
@@ -269,6 +315,12 @@ void resampler_write_sample(void *_r, short s)
 {
     resampler * r = ( resampler * ) _r;
 
+    if ( r->delay_added < 0 )
+    {
+        r->delay_added = 0;
+        r->write_filled = resampler_input_delay( r );
+    }
+    
     if ( r->write_filled < resampler_buffer_size )
     {
         float s32 = s;
@@ -287,6 +339,12 @@ void resampler_write_sample_fixed(void *_r, int s, unsigned char depth)
 {
     resampler * r = ( resampler * ) _r;
     
+    if ( r->delay_added < 0 )
+    {
+        r->delay_added = 0;
+        r->write_filled = resampler_input_delay( r );
+    }
+    
     if ( r->write_filled < resampler_buffer_size )
     {
         float s32 = s;
@@ -809,11 +867,23 @@ static void resampler_fill(resampler * r)
     }
 }
 
+static void resampler_fill_and_remove_delay(resampler * r)
+{
+    resampler_fill( r );
+    if ( r->delay_removed < 0 )
+    {
+        int delay = resampler_output_delay( r );
+        r->delay_removed = 0;
+        while ( delay-- )
+            resampler_remove_sample( r );
+    }
+}
+
 int resampler_get_sample_count(void *_r)
 {
     resampler * r = ( resampler * ) _r;
     if ( r->read_filled < 1 && (r->quality != RESAMPLER_QUALITY_BLEP || r->inv_phase_inc))
-        resampler_fill( r );
+        resampler_fill_and_remove_delay( r );
     return r->read_filled;
 }
 
@@ -821,7 +891,7 @@ float resampler_get_sample(void *_r)
 {
     resampler * r = ( resampler * ) _r;
     if ( r->read_filled < 1 && r->phase_inc)
-        resampler_fill( r );
+        resampler_fill_and_remove_delay( r );
     if ( r->read_filled < 1 )
         return 0;
     if ( r->quality == RESAMPLER_QUALITY_BLEP )
@@ -840,6 +910,8 @@ void resampler_remove_sample(void *_r)
             r->accumulator += r->buffer_out[ r->read_pos ];
             r->buffer_out[ r->read_pos ] = 0;
             r->accumulator -= r->accumulator * (1.0 / 8192.0);
+            if (fabs(r->accumulator) < 1e-20)
+                r->accumulator = 0;
         }
         --r->read_filled;
         r->read_pos = ( r->read_pos + 1 ) % resampler_buffer_size;