Merge pull request #8629 from dcooperdalrymple/synthio-note-loop

Add loop_start and loop_end properties to synthio.Note for waveshaping and sampling capabilities.

shared-bindings/synthio/Note.c

@@ -40,11 +40,15 @@ static const mp_arg_t note_properties[] = {
     { MP_QSTR_amplitude, MP_ARG_OBJ | MP_ARG_KW_ONLY, {.u_obj = MP_ROM_INT(1) } },
     { MP_QSTR_bend, MP_ARG_OBJ | MP_ARG_KW_ONLY, {.u_obj = MP_ROM_INT(0) } },
     { MP_QSTR_waveform, MP_ARG_OBJ | MP_ARG_KW_ONLY, {.u_obj = MP_ROM_NONE } },
+    { MP_QSTR_waveform_loop_start, MP_ARG_OBJ, {.u_obj = MP_ROM_INT(0) } },
+    { MP_QSTR_waveform_loop_end, MP_ARG_OBJ, {.u_obj = MP_ROM_INT(SYNTHIO_WAVEFORM_SIZE) } },
     { MP_QSTR_envelope, MP_ARG_OBJ | MP_ARG_KW_ONLY, {.u_obj = MP_ROM_NONE } },
     { MP_QSTR_filter, MP_ARG_OBJ | MP_ARG_KW_ONLY, {.u_obj = MP_ROM_NONE } },
     { MP_QSTR_ring_frequency, MP_ARG_OBJ, {.u_obj = MP_ROM_INT(0) } },
     { MP_QSTR_ring_bend, MP_ARG_OBJ, {.u_obj = MP_ROM_INT(0) } },
     { MP_QSTR_ring_waveform, MP_ARG_OBJ | MP_ARG_KW_ONLY, {.u_obj = MP_ROM_NONE } },
+    { MP_QSTR_ring_waveform_loop_start, MP_ARG_OBJ, {.u_obj = MP_ROM_INT(0) } },
+    { MP_QSTR_ring_waveform_loop_end, MP_ARG_OBJ, {.u_obj = MP_ROM_INT(SYNTHIO_WAVEFORM_SIZE) } },
 };
 //| class Note:
 //|     def __init__(
@@ -53,6 +57,8 @@ static const mp_arg_t note_properties[] = {
 //|         frequency: float,
 //|         panning: BlockInput = 0.0,
 //|         waveform: Optional[ReadableBuffer] = None,
+//|         waveform_loop_start: int = 0,
+//|         waveform_loop_end: int = waveform_max_length,
 //|         envelope: Optional[Envelope] = None,
 //|         amplitude: BlockInput = 0.0,
 //|         bend: BlockInput = 0.0,
@@ -60,6 +66,8 @@ static const mp_arg_t note_properties[] = {
 //|         ring_frequency: float = 0.0,
 //|         ring_bend: float = 0.0,
 //|         ring_waveform: Optional[ReadableBuffer] = 0.0,
+//|         ring_waveform_loop_start: int = 0,
+//|         ring_waveform_loop_end: int = waveform_max_length,
 //|     ) -> None:
 //|         """Construct a Note object, with a frequency in Hz, and optional panning, waveform, envelope, tremolo (volume change) and bend (frequency change).
 //|
@@ -210,6 +218,53 @@ MP_PROPERTY_GETSET(synthio_note_waveform_obj,
     (mp_obj_t)&synthio_note_get_waveform_obj,
     (mp_obj_t)&synthio_note_set_waveform_obj);
 
+//|     waveform_loop_start: int
+//|     """The sample index of where to begin looping waveform data.
+//|
+//|     Values outside the range ``0`` to ``waveform_max_length-1`` (inclusive) are rejected with a `ValueError`.
+//|
+//|     Values greater than or equal to the actual waveform length are treated as 0."""
+STATIC mp_obj_t synthio_note_get_waveform_loop_start(mp_obj_t self_in) {
+    synthio_note_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    return mp_obj_new_int(common_hal_synthio_note_get_waveform_loop_start(self));
+}
+MP_DEFINE_CONST_FUN_OBJ_1(synthio_note_get_waveform_loop_start_obj, synthio_note_get_waveform_loop_start);
+
+STATIC mp_obj_t synthio_note_set_waveform_loop_start(mp_obj_t self_in, mp_obj_t arg) {
+    synthio_note_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    common_hal_synthio_note_set_waveform_loop_start(self, mp_obj_get_int(arg));
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_2(synthio_note_set_waveform_loop_start_obj, synthio_note_set_waveform_loop_start);
+MP_PROPERTY_GETSET(synthio_note_waveform_loop_start_obj,
+    (mp_obj_t)&synthio_note_get_waveform_loop_start_obj,
+    (mp_obj_t)&synthio_note_set_waveform_loop_start_obj);
+
+//|     waveform_loop_end: int
+//|     """The sample index of where to end looping waveform data.
+//|
+//|     Values outside the range ``1`` to ``waveform_max_length`` (inclusive) are rejected with a `ValueError`.
+//|
+//|     If the value is greater than the actual waveform length, or less than or equal to the loop start, the loop will occur at the end of the waveform.
+//|
+//|     Use the `synthio.waveform_max_length` constant to set the loop point at the end of the wave form, no matter its length."""
+//|
+STATIC mp_obj_t synthio_note_get_waveform_loop_end(mp_obj_t self_in) {
+    synthio_note_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    return mp_obj_new_int(common_hal_synthio_note_get_waveform_loop_end(self));
+}
+MP_DEFINE_CONST_FUN_OBJ_1(synthio_note_get_waveform_loop_end_obj, synthio_note_get_waveform_loop_end);
+
+STATIC mp_obj_t synthio_note_set_waveform_loop_end(mp_obj_t self_in, mp_obj_t arg) {
+    synthio_note_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    common_hal_synthio_note_set_waveform_loop_end(self, mp_obj_get_int(arg));
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_2(synthio_note_set_waveform_loop_end_obj, synthio_note_set_waveform_loop_end);
+MP_PROPERTY_GETSET(synthio_note_waveform_loop_end_obj,
+    (mp_obj_t)&synthio_note_get_waveform_loop_end_obj,
+    (mp_obj_t)&synthio_note_set_waveform_loop_end_obj);
+
 
 //|     envelope: Envelope
 //|     """The envelope of this note"""
@@ -296,6 +351,53 @@ MP_PROPERTY_GETSET(synthio_note_ring_waveform_obj,
     (mp_obj_t)&synthio_note_get_ring_waveform_obj,
     (mp_obj_t)&synthio_note_set_ring_waveform_obj);
 
+//|     ring_waveform_loop_start: int
+//|     """The sample index of where to begin looping waveform data.
+//|
+//|     Values outside the range ``0`` to ``waveform_max_length-1`` (inclusive) are rejected with a `ValueError`.
+//|
+//|     Values greater than or equal to the actual waveform length are treated as 0."""
+STATIC mp_obj_t synthio_note_get_ring_waveform_loop_start(mp_obj_t self_in) {
+    synthio_note_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    return mp_obj_new_int(common_hal_synthio_note_get_ring_waveform_loop_start(self));
+}
+MP_DEFINE_CONST_FUN_OBJ_1(synthio_note_get_ring_waveform_loop_start_obj, synthio_note_get_ring_waveform_loop_start);
+
+STATIC mp_obj_t synthio_note_set_ring_waveform_loop_start(mp_obj_t self_in, mp_obj_t arg) {
+    synthio_note_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    common_hal_synthio_note_set_ring_waveform_loop_start(self, mp_obj_get_int(arg));
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_2(synthio_note_set_ring_waveform_loop_start_obj, synthio_note_set_ring_waveform_loop_start);
+MP_PROPERTY_GETSET(synthio_note_ring_waveform_loop_start_obj,
+    (mp_obj_t)&synthio_note_get_ring_waveform_loop_start_obj,
+    (mp_obj_t)&synthio_note_set_ring_waveform_loop_start_obj);
+
+//|     ring_waveform_loop_end: int
+//|     """The sample index of where to end looping waveform data.
+//|
+//|     Values outside the range ``1`` to ``waveform_max_length`` (inclusive) are rejected with a `ValueError`.
+//|
+//|     If the value is greater than the actual waveform length, or less than or equal to the loop start, the loop will occur at the end of the waveform.
+//|
+//|     Use the `synthio.waveform_max_length` constant to set the loop point at the end of the wave form, no matter its length."""
+//|
+STATIC mp_obj_t synthio_note_get_ring_waveform_loop_end(mp_obj_t self_in) {
+    synthio_note_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    return mp_obj_new_int(common_hal_synthio_note_get_ring_waveform_loop_end(self));
+}
+MP_DEFINE_CONST_FUN_OBJ_1(synthio_note_get_ring_waveform_loop_end_obj, synthio_note_get_ring_waveform_loop_end);
+
+STATIC mp_obj_t synthio_note_set_ring_waveform_loop_end(mp_obj_t self_in, mp_obj_t arg) {
+    synthio_note_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    common_hal_synthio_note_set_ring_waveform_loop_end(self, mp_obj_get_int(arg));
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_2(synthio_note_set_ring_waveform_loop_end_obj, synthio_note_set_ring_waveform_loop_end);
+MP_PROPERTY_GETSET(synthio_note_ring_waveform_loop_end_obj,
+    (mp_obj_t)&synthio_note_get_ring_waveform_loop_end_obj,
+    (mp_obj_t)&synthio_note_set_ring_waveform_loop_end_obj);
+
 
 
 static void note_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
@@ -308,12 +410,16 @@ STATIC const mp_rom_map_elem_t synthio_note_locals_dict_table[] = {
     { MP_ROM_QSTR(MP_QSTR_filter), MP_ROM_PTR(&synthio_note_filter_obj) },
     { MP_ROM_QSTR(MP_QSTR_panning), MP_ROM_PTR(&synthio_note_panning_obj) },
     { MP_ROM_QSTR(MP_QSTR_waveform), MP_ROM_PTR(&synthio_note_waveform_obj) },
+    { MP_ROM_QSTR(MP_QSTR_waveform_loop_start), MP_ROM_PTR(&synthio_note_waveform_loop_start_obj) },
+    { MP_ROM_QSTR(MP_QSTR_waveform_loop_end), MP_ROM_PTR(&synthio_note_waveform_loop_end_obj) },
     { MP_ROM_QSTR(MP_QSTR_envelope), MP_ROM_PTR(&synthio_note_envelope_obj) },
     { MP_ROM_QSTR(MP_QSTR_amplitude), MP_ROM_PTR(&synthio_note_amplitude_obj) },
     { MP_ROM_QSTR(MP_QSTR_bend), MP_ROM_PTR(&synthio_note_bend_obj) },
     { MP_ROM_QSTR(MP_QSTR_ring_frequency), MP_ROM_PTR(&synthio_note_ring_frequency_obj) },
     { MP_ROM_QSTR(MP_QSTR_ring_bend), MP_ROM_PTR(&synthio_note_ring_bend_obj) },
     { MP_ROM_QSTR(MP_QSTR_ring_waveform), MP_ROM_PTR(&synthio_note_ring_waveform_obj) },
+    { MP_ROM_QSTR(MP_QSTR_ring_waveform_loop_start), MP_ROM_PTR(&synthio_note_ring_waveform_loop_start_obj) },
+    { MP_ROM_QSTR(MP_QSTR_ring_waveform_loop_end), MP_ROM_PTR(&synthio_note_ring_waveform_loop_end_obj) },
 };
 STATIC MP_DEFINE_CONST_DICT(synthio_note_locals_dict, synthio_note_locals_dict_table);
 

shared-bindings/synthio/Note.h

@@ -24,6 +24,12 @@ void common_hal_synthio_note_set_bend(synthio_note_obj_t *self, mp_obj_t value);
 mp_obj_t common_hal_synthio_note_get_waveform_obj(synthio_note_obj_t *self);
 void common_hal_synthio_note_set_waveform(synthio_note_obj_t *self, mp_obj_t value);
 
+mp_int_t common_hal_synthio_note_get_waveform_loop_start(synthio_note_obj_t *self);
+void common_hal_synthio_note_set_waveform_loop_start(synthio_note_obj_t *self, mp_int_t value_in);
+
+mp_int_t common_hal_synthio_note_get_waveform_loop_end(synthio_note_obj_t *self);
+void common_hal_synthio_note_set_waveform_loop_end(synthio_note_obj_t *self, mp_int_t value_in);
+
 mp_float_t common_hal_synthio_note_get_ring_frequency(synthio_note_obj_t *self);
 void common_hal_synthio_note_set_ring_frequency(synthio_note_obj_t *self, mp_float_t value);
 
@@ -33,5 +39,11 @@ void common_hal_synthio_note_set_ring_bend(synthio_note_obj_t *self, mp_obj_t va
 mp_obj_t common_hal_synthio_note_get_ring_waveform_obj(synthio_note_obj_t *self);
 void common_hal_synthio_note_set_ring_waveform(synthio_note_obj_t *self, mp_obj_t value);
 
+mp_int_t common_hal_synthio_note_get_ring_waveform_loop_start(synthio_note_obj_t *self);
+void common_hal_synthio_note_set_ring_waveform_loop_start(synthio_note_obj_t *self, mp_int_t value_in);
+
+mp_int_t common_hal_synthio_note_get_ring_waveform_loop_end(synthio_note_obj_t *self);
+void common_hal_synthio_note_set_ring_waveform_loop_end(synthio_note_obj_t *self, mp_int_t value_in);
+
 mp_obj_t common_hal_synthio_note_get_envelope_obj(synthio_note_obj_t *self);
 void common_hal_synthio_note_set_envelope(synthio_note_obj_t *self, mp_obj_t value);

shared-bindings/synthio/__init__.c

@@ -304,6 +304,11 @@ STATIC mp_obj_t voct_to_hz(mp_obj_t arg) {
 }
 MP_DEFINE_CONST_FUN_OBJ_1(synthio_voct_to_hz_obj, voct_to_hz);
 
+//|
+//| waveform_max_length: int
+//| """The maximum number of samples permitted in a waveform"""
+//|
+
 #if CIRCUITPY_AUDIOCORE_DEBUG
 STATIC mp_obj_t synthio_lfo_tick(size_t n, const mp_obj_t *args) {
     shared_bindings_synthio_lfo_tick(48000);
@@ -333,6 +338,7 @@ STATIC const mp_rom_map_elem_t synthio_module_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR_Envelope), MP_ROM_PTR(&synthio_envelope_type_obj) },
     { MP_ROM_QSTR(MP_QSTR_midi_to_hz), MP_ROM_PTR(&synthio_midi_to_hz_obj) },
     { MP_ROM_QSTR(MP_QSTR_voct_to_hz), MP_ROM_PTR(&synthio_voct_to_hz_obj) },
+    { MP_ROM_QSTR(MP_QSTR_waveform_max_length), MP_ROM_INT(SYNTHIO_WAVEFORM_SIZE) },
     #if CIRCUITPY_AUDIOCORE_DEBUG
     { MP_ROM_QSTR(MP_QSTR_lfo_tick), MP_ROM_PTR(&synthio_lfo_tick_obj) },
     #endif

shared-bindings/synthio/__init__.h

@@ -29,6 +29,8 @@
 #include "py/objnamedtuple.h"
 #include "py/enum.h"
 
+#define SYNTHIO_WAVEFORM_SIZE 16384
+
 typedef enum {
     SYNTHIO_ENVELOPE_STATE_ATTACK, SYNTHIO_ENVELOPE_STATE_DECAY,
     SYNTHIO_ENVELOPE_STATE_SUSTAIN, SYNTHIO_ENVELOPE_STATE_RELEASE

shared-module/synthio/Note.c

@@ -120,6 +120,24 @@ void common_hal_synthio_note_set_waveform(synthio_note_obj_t *self, mp_obj_t wav
     self->waveform_obj = waveform_in;
 }
 
+mp_int_t common_hal_synthio_note_get_waveform_loop_start(synthio_note_obj_t *self) {
+    return self->waveform_loop_start;
+}
+
+void common_hal_synthio_note_set_waveform_loop_start(synthio_note_obj_t *self, mp_int_t value_in) {
+    mp_int_t val = mp_arg_validate_int_range(value_in, 0, SYNTHIO_WAVEFORM_SIZE - 1, MP_QSTR_waveform_loop_start);
+    self->waveform_loop_start = val;
+}
+
+mp_int_t common_hal_synthio_note_get_waveform_loop_end(synthio_note_obj_t *self) {
+    return self->waveform_loop_end;
+}
+
+void common_hal_synthio_note_set_waveform_loop_end(synthio_note_obj_t *self, mp_int_t value_in) {
+    mp_int_t val = mp_arg_validate_int_range(value_in, 1, SYNTHIO_WAVEFORM_SIZE, MP_QSTR_waveform_loop_end);
+    self->waveform_loop_end = val;
+}
+
 mp_obj_t common_hal_synthio_note_get_ring_waveform_obj(synthio_note_obj_t *self) {
     return self->ring_waveform_obj;
 }
@@ -135,6 +153,24 @@ void common_hal_synthio_note_set_ring_waveform(synthio_note_obj_t *self, mp_obj_
     self->ring_waveform_obj = ring_waveform_in;
 }
 
+mp_int_t common_hal_synthio_note_get_ring_waveform_loop_start(synthio_note_obj_t *self) {
+    return self->ring_waveform_loop_start;
+}
+
+void common_hal_synthio_note_set_ring_waveform_loop_start(synthio_note_obj_t *self, mp_int_t value_in) {
+    mp_int_t val = mp_arg_validate_int_range(value_in, 0, SYNTHIO_WAVEFORM_SIZE - 1, MP_QSTR_ring_waveform_loop_start);
+    self->ring_waveform_loop_start = val;
+}
+
+mp_int_t common_hal_synthio_note_get_ring_waveform_loop_end(synthio_note_obj_t *self) {
+    return self->ring_waveform_loop_end;
+}
+
+void common_hal_synthio_note_set_ring_waveform_loop_end(synthio_note_obj_t *self, mp_int_t value_in) {
+    mp_int_t val = mp_arg_validate_int_range(value_in, 1, SYNTHIO_WAVEFORM_SIZE, MP_QSTR_ring_waveform_loop_end);
+    self->ring_waveform_loop_end = val;
+}
+
 void synthio_note_recalculate(synthio_note_obj_t *self, int32_t sample_rate) {
     if (sample_rate == self->sample_rate) {
         return;

shared-module/synthio/Note.h

@@ -48,7 +48,9 @@ typedef struct synthio_note_obj {
     int32_t ring_frequency_scaled, ring_frequency_bent;
 
     mp_buffer_info_t waveform_buf;
+    uint32_t waveform_loop_start, waveform_loop_end;
     mp_buffer_info_t ring_waveform_buf;
+    uint32_t ring_waveform_loop_start, ring_waveform_loop_end;
     synthio_envelope_definition_t envelope_def;
 } synthio_note_obj_t;
 

shared-module/synthio/__init__.c

@@ -180,10 +180,12 @@ static bool synth_note_into_buffer(synthio_synth_t *synth, int chan, int32_t *ou
 
     uint32_t dds_rate;
     const int16_t *waveform = synth->waveform_bufinfo.buf;
+    uint32_t waveform_start = 0;
     uint32_t waveform_length = synth->waveform_bufinfo.len;
 
     uint32_t ring_dds_rate = 0;
     const int16_t *ring_waveform = NULL;
+    uint32_t ring_waveform_start = 0;
     uint32_t ring_waveform_length = 0;
 
     if (mp_obj_is_small_int(note_obj)) {
@@ -202,12 +204,24 @@ static bool synth_note_into_buffer(synthio_synth_t *synth, int chan, int32_t *ou
         if (note->waveform_buf.buf) {
             waveform = note->waveform_buf.buf;
             waveform_length = note->waveform_buf.len;
+            if (note->waveform_loop_start > 0 && note->waveform_loop_start < waveform_length) {
+                waveform_start = note->waveform_loop_start;
             }
-        dds_rate = synthio_frequency_convert_scaled_to_dds((uint64_t)frequency_scaled * waveform_length, sample_rate);
+            if (note->waveform_loop_end > waveform_start && note->waveform_loop_end < waveform_length) {
+                waveform_length = note->waveform_loop_end;
+            }
+        }
+        dds_rate = synthio_frequency_convert_scaled_to_dds((uint64_t)frequency_scaled * (waveform_length - waveform_start), sample_rate);
         if (note->ring_frequency_scaled != 0 && note->ring_waveform_buf.buf) {
             ring_waveform = note->ring_waveform_buf.buf;
             ring_waveform_length = note->ring_waveform_buf.len;
-            ring_dds_rate = synthio_frequency_convert_scaled_to_dds((uint64_t)note->ring_frequency_bent * ring_waveform_length, sample_rate);
+            if (note->ring_waveform_loop_start > 0 && note->ring_waveform_loop_start < ring_waveform_length) {
+                ring_waveform_start = note->waveform_loop_start;
+            }
+            if (note->ring_waveform_loop_end > ring_waveform_start && note->ring_waveform_loop_end < ring_waveform_length) {
+                ring_waveform_length = note->ring_waveform_loop_end;
+            }
+            ring_dds_rate = synthio_frequency_convert_scaled_to_dds((uint64_t)note->ring_frequency_bent * (ring_waveform_length - ring_waveform_start), sample_rate);
             uint32_t lim = ring_waveform_length << SYNTHIO_FREQUENCY_SHIFT;
             if (ring_dds_rate > lim / sizeof(int16_t)) {
                 ring_dds_rate = 0; // can't ring at that frequency
@@ -215,6 +229,7 @@ static bool synth_note_into_buffer(synthio_synth_t *synth, int chan, int32_t *ou
         }
     }
 
+    uint32_t offset = waveform_start << SYNTHIO_FREQUENCY_SHIFT;
     uint32_t lim = waveform_length << SYNTHIO_FREQUENCY_SHIFT;
     uint32_t accum = synth->accum[chan];
 
@@ -225,7 +240,7 @@ static bool synth_note_into_buffer(synthio_synth_t *synth, int chan, int32_t *ou
 
     // can happen if note waveform gets set mid-note, but the expensive modulo is usually avoided
     if (accum > lim) {
-        accum %= lim;
+        accum = accum % lim + offset;
     }
 
     // first, fill with waveform
@@ -233,7 +248,7 @@ static bool synth_note_into_buffer(synthio_synth_t *synth, int chan, int32_t *ou
         accum += dds_rate;
         // because dds_rate is low enough, the subtraction is guaranteed to go back into range, no expensive modulo needed
         if (accum > lim) {
-            accum -= lim;
+            accum = accum - lim + offset;
         }
         int16_t idx = accum >> SYNTHIO_FREQUENCY_SHIFT;
         out_buffer32[i] = waveform[idx];
@@ -249,18 +264,19 @@ static bool synth_note_into_buffer(synthio_synth_t *synth, int chan, int32_t *ou
 
         // now modulate by ring and accumulate
         accum = synth->ring_accum[chan];
+        offset = ring_waveform_start << SYNTHIO_FREQUENCY_SHIFT;
         lim = ring_waveform_length << SYNTHIO_FREQUENCY_SHIFT;
 
         // can happen if note waveform gets set mid-note, but the expensive modulo is usually avoided
         if (accum > lim) {
-            accum %= lim;
+            accum = accum % lim + offset;
         }
 
         for (uint16_t i = 0; i < dur; i++) {
             accum += ring_dds_rate;
             // because dds_rate is low enough, the subtraction is guaranteed to go back into range, no expensive modulo needed
             if (accum > lim) {
-                accum -= lim;
+                accum = accum - lim + offset;
             }
             int16_t idx = accum >> SYNTHIO_FREQUENCY_SHIFT;
             int16_t wi = (ring_waveform[idx] * out_buffer32[i]) / 32768;
@@ -434,7 +450,7 @@ STATIC void parse_common(mp_buffer_info_t *bufinfo, mp_obj_t o, int16_t what, mp
 
 void synthio_synth_parse_waveform(mp_buffer_info_t *bufinfo_waveform, mp_obj_t waveform_obj) {
     *bufinfo_waveform = ((mp_buffer_info_t) { .buf = (void *)square_wave, .len = 2 });
-    parse_common(bufinfo_waveform, waveform_obj, MP_QSTR_waveform, 16384);
+    parse_common(bufinfo_waveform, waveform_obj, MP_QSTR_waveform, SYNTHIO_WAVEFORM_SIZE);
 }
 
 STATIC int find_channel_with_note(synthio_synth_t *synth, mp_obj_t note) {