Add pitch table for audio resampling at 44100Hz

2 files changed, 24 insertions, 31 deletions

diff --git a/src/main.c b/src/main.c
index a5a0628..fa82999 100644
--- a/src/main.c
+++ b/src/main.c
@@ -126,11 +126,8 @@ audio_talk(Device *d, u8 b0, u8 w) {
             // Disable the channel before updating.
                 c->data = NULL;
 
-                // Initialization.
-        c->inc = (44100 << 12) / AUDIO_FREQ;
-        c->pos = 0;
-
         // Data.
+        c->pos = 0;
                 c->length = mempeek16(d->dat, 0xa);
                 c->length <<= 12; // fixed point.
                 c->data = &d->mem[mempeek16(d->dat, 0xc)];
@@ -149,8 +146,14 @@ audio_talk(Device *d, u8 b0, u8 w) {
 
         // Pitch
                 c->pitch = d->dat[0xf] & 0x7f;
+
+                // Initialization.
+        c->inc = pitch_table_44100[c->pitch];
+
             txt_position(0, 0);
         txt_printf("note: %d     \n", c->pitch);
+        txt_printf("inc: %ld     \n", c->inc);
+        txt_printf("length: %ld     \n", c->length >> 12);
         }
 }
 
diff --git a/src/uxn/devices/apu.c b/src/uxn/devices/apu.c
index 2b1c8ff..96b9058 100644
--- a/src/uxn/devices/apu.c
+++ b/src/uxn/devices/apu.c
@@ -1,32 +1,22 @@
-#define SAMPLE_FREQUENCY 44100
-#define NOTE_PERIOD (SAMPLE_FREQUENCY * 0x4000 / 11025)
-#define ADSR_STEP (SAMPLE_FREQUENCY / 0xf)
-
-static u16 pitch_table[] = {
-    12173, 11490, 10845, 10237, 9662, 9120, 8608, 8125,
-    7669, 7238, 6832, 6448, 6086, 5745, 5422, 5118,
-    4831, 4560, 4304, 4062, 3834, 3619, 3416, 3224,
-    3043, 2872, 2711, 2559, 2415, 2280, 2152, 2031,
-    1917, 1809, 1708, 1612, 1521, 1436, 1355, 1279,
-    1207, 1140, 1076, 1015, 958, 904, 854, 806,
-    760, 718, 677, 639, 603, 570, 538, 507,
-    479, 452, 427, 403, 380, 359, 338, 319,
-    301, 285, 269, 253, 239, 226, 213, 201,
-    190, 179, 169, 159, 150, 142, 134, 126,
-    119, 113, 106, 100, 95, 89, 84, 79,
-    75, 71, 67, 63, 59, 56, 53, 50,
-    47, 44, 42, 39, 37, 35, 33, 31,
-    29, 28, 26, 25, 23, 22, 21, 19,
-    18, 17, 16, 15, 14, 14, 13, 12,
-    2,
+// Calculated as (44100 << 12) / 18157 for C4
+static u32 pitch_table_44100[] = {
+    310,    329,    348,    369,    391,    414,    439,    465,
+    493,    522,    553,    586,    621,    658,    697,    739,
+    783,    829,    879,    931,    987,    1045,   1107,   1173,
+    1243,   1317,   1395,   1478,   1566,   1659,   1758,   1863,
+    1974,   2091,   2215,   2347,   2487,   2634,   2791,   2957,
+    3133,   3319,   3517,   3726,   3948,   4182,   4431,   4695,
+    4974,   5269,   5583,   5915,   6267,   6639,   7034,   7452,
+    7896,   8365,   8863,   9390,   9948,   10539,  11166,  11830,
+    12534,  13279,  14069,  14905,  15792,  16731,  17726,  18780,
+    19896,  21079,  22333,  23661,  25068,  26559,  28138,  29811,
+    31584,  33462,  35452,  37560,  39793,  42159,  44666,  47322,
+    50136,  53118,  56276,  59623,  63168,  66924,  70904,  75120,
+    79587,  84319,  89333,  94645,  100273, 106236, 112553, 119246,
+    126337, 133849, 141808, 150241, 159174, 168639, 178667, 189291,
+    200547, 212472, 225107, 238492, 252674, 267699, 283617, 300482,
 };
 
-s8 square_wave[] =  {
-    (s8)0x00 + (s8)0x80, (s8)0xFF + (s8)0x80
-};
-
-#include "text.h"
-
 //
 //       REG_TM0D                    frequency    buffer size
 //          |                            |            |