Pitch shift audio effect

ports/unix/variants/coverage/mpconfigvariant.mk

@@ -34,6 +34,7 @@ SRC_BITMAP := \
 	shared-bindings/audiocore/RawSample.c \
 	shared-bindings/audiocore/WaveFile.c \
 	shared-bindings/audiodelays/Echo.c \
+	shared-bindings/audiodelays/PitchShift.c \
 	shared-bindings/audiodelays/__init__.c \
 	shared-bindings/audiofilters/Distortion.c \
 	shared-bindings/audiofilters/Filter.c \
@@ -77,6 +78,7 @@ SRC_BITMAP := \
 	shared-module/audiocore/RawSample.c \
 	shared-module/audiocore/WaveFile.c \
 	shared-module/audiodelays/Echo.c \
+	shared-module/audiodelays/PitchShift.c \
 	shared-module/audiodelays/__init__.c \
 	shared-module/audiofilters/Distortion.c \
 	shared-module/audiofilters/Filter.c \

py/circuitpy_defns.mk

@@ -624,6 +624,7 @@ SRC_SHARED_MODULE_ALL = \
 	audiocore/WaveFile.c \
 	audiocore/__init__.c \
 	audiodelays/Echo.c \
+	audiodelays/PitchShift.c \
 	audiodelays/__init__.c \
 	audiofilters/Distortion.c \
 	audiofilters/Filter.c \

shared-bindings/audiodelays/PitchShift.c

@@ -0,0 +1,261 @@
+// This file is part of the CircuitPython project: https://circuitpython.org
+//
+// SPDX-FileCopyrightText: Copyright (c) 2025 Cooper Dalrymple
+//
+// SPDX-License-Identifier: MIT
+
+#include <stdint.h>
+
+#include "shared-bindings/audiodelays/PitchShift.h"
+#include "shared-bindings/audiocore/__init__.h"
+#include "shared-module/audiodelays/PitchShift.h"
+
+#include "shared/runtime/context_manager_helpers.h"
+#include "py/binary.h"
+#include "py/objproperty.h"
+#include "py/runtime.h"
+#include "shared-bindings/util.h"
+#include "shared-module/synthio/block.h"
+
+//| class PitchShift:
+//|     """A pitch shift effect"""
+//|
+//|     def __init__(
+//|         self,
+//|         semitones: synthio.BlockInput = 0.0,
+//|         mix: synthio.BlockInput = 1.0,
+//|         window: int = 1024,
+//|         overlap: int = 128,
+//|         buffer_size: int = 512,
+//|         sample_rate: int = 8000,
+//|         bits_per_sample: int = 16,
+//|         samples_signed: bool = True,
+//|         channel_count: int = 1,
+//|     ) -> None:
+//|         """Create a pitch shift effect where the original sample play back is altered to change the
+//|            the perceived pitch by a factor of semi-tones (1/12th of an octave). This effect will cause
+//|            a slight delay in the output depending on the size of the window and overlap buffers.
+//|
+//|            The mix parameter allows you to change how much of the unchanged sample passes through to
+//|            the output to how much of the effect audio you hear as the output.
+//|
+//|         :param synthio.BlockInput semitones: The amount of pitch shifting in semitones (1/12th of an octave)
+//|         :param synthio.BlockInput mix: The mix as a ratio of the sample (0.0) to the effect (1.0)
+//|         :param int window: The total size in bytes of the window buffer used alter the playback pitch
+//|         :param int overlap: The total size in bytes of the overlap buffer used to prevent popping in the output. If set as 0, no overlap will be used.
+//|         :param int buffer_size: The total size in bytes of each of the two playback buffers to use
+//|         :param int sample_rate: The sample rate to be used
+//|         :param int channel_count: The number of channels the source samples contain. 1 = mono; 2 = stereo.
+//|         :param int bits_per_sample: The bits per sample of the effect
+//|         :param bool samples_signed: Effect is signed (True) or unsigned (False)
+//|
+//|         Shifting the pitch of a synth by 5 semitones::
+//|
+//|           import time
+//|           import board
+//|           import audiobusio
+//|           import synthio
+//|           import audiodelays
+//|
+//|           audio = audiobusio.I2SOut(bit_clock=board.GP0, word_select=board.GP1, data=board.GP2)
+//|           synth = synthio.Synthesizer(channel_count=1, sample_rate=44100)
+//|           pitch_shift = audiodelays.PitchShift(semitones=5.0, mix=0.5, window=2048, overlap=256, buffer_size=1024, channel_count=1, sample_rate=44100)
+//|           pitch_shift.play(synth)
+//|           audio.play(pitch_shift)
+//|
+//|           while True:
+//|               for notenum in (60, 64, 67, 71):
+//|                   synth.press(notenum)
+//|                   time.sleep(0.25)
+//|                   synth.release_all()"""
+//|         ...
+//|
+static mp_obj_t audiodelays_pitch_shift_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) {
+    enum { ARG_semitones, ARG_mix, ARG_window, ARG_overlap, ARG_buffer_size, ARG_sample_rate, ARG_bits_per_sample, ARG_samples_signed, ARG_channel_count, };
+    static const mp_arg_t allowed_args[] = {
+        { MP_QSTR_semitones, MP_ARG_OBJ | MP_ARG_KW_ONLY, {.u_obj = MP_ROM_INT(0)} },
+        { MP_QSTR_mix, MP_ARG_OBJ | MP_ARG_KW_ONLY,  {.u_obj = MP_ROM_INT(1)} },
+        { MP_QSTR_window, MP_ARG_INT | MP_ARG_KW_ONLY, {.u_int = 1024} },
+        { MP_QSTR_overlap, MP_ARG_INT | MP_ARG_KW_ONLY, {.u_int = 128} },
+        { MP_QSTR_buffer_size, MP_ARG_INT | MP_ARG_KW_ONLY, {.u_int = 512} },
+        { MP_QSTR_sample_rate, MP_ARG_INT | MP_ARG_KW_ONLY, {.u_int = 8000} },
+        { MP_QSTR_bits_per_sample, MP_ARG_INT | MP_ARG_KW_ONLY, {.u_int = 16} },
+        { MP_QSTR_samples_signed, MP_ARG_BOOL | MP_ARG_KW_ONLY, {.u_bool = true} },
+        { MP_QSTR_channel_count, MP_ARG_INT | MP_ARG_KW_ONLY, {.u_int = 1 } },
+    };
+
+    mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
+    mp_arg_parse_all_kw_array(n_args, n_kw, all_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
+
+    mp_int_t channel_count = mp_arg_validate_int_range(args[ARG_channel_count].u_int, 1, 2, MP_QSTR_channel_count);
+    mp_int_t sample_rate = mp_arg_validate_int_min(args[ARG_sample_rate].u_int, 1, MP_QSTR_sample_rate);
+    mp_int_t bits_per_sample = args[ARG_bits_per_sample].u_int;
+    if (bits_per_sample != 8 && bits_per_sample != 16) {
+        mp_raise_ValueError(MP_ERROR_TEXT("bits_per_sample must be 8 or 16"));
+    }
+
+    audiodelays_pitch_shift_obj_t *self = mp_obj_malloc(audiodelays_pitch_shift_obj_t, &audiodelays_pitch_shift_type);
+    common_hal_audiodelays_pitch_shift_construct(self, args[ARG_semitones].u_obj, args[ARG_mix].u_obj, args[ARG_window].u_int, args[ARG_overlap].u_int, args[ARG_buffer_size].u_int, bits_per_sample, args[ARG_samples_signed].u_bool, channel_count, sample_rate);
+
+    return MP_OBJ_FROM_PTR(self);
+}
+
+
+//|     def deinit(self) -> None:
+//|         """Deinitialises the PitchShift."""
+//|         ...
+//|
+static mp_obj_t audiodelays_pitch_shift_deinit(mp_obj_t self_in) {
+    audiodelays_pitch_shift_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    common_hal_audiodelays_pitch_shift_deinit(self);
+    return mp_const_none;
+}
+static MP_DEFINE_CONST_FUN_OBJ_1(audiodelays_pitch_shift_deinit_obj, audiodelays_pitch_shift_deinit);
+
+static void check_for_deinit(audiodelays_pitch_shift_obj_t *self) {
+    audiosample_check_for_deinit(&self->base);
+}
+
+
+//|     def __enter__(self) -> PitchShift:
+//|         """No-op used by Context Managers."""
+//|         ...
+//|
+//  Provided by context manager helper.
+
+//|     def __exit__(self) -> None:
+//|         """Automatically deinitializes when exiting a context. See
+//|         :ref:`lifetime-and-contextmanagers` for more info."""
+//|         ...
+//|
+static mp_obj_t audiodelays_pitch_shift_obj___exit__(size_t n_args, const mp_obj_t *args) {
+    (void)n_args;
+    common_hal_audiodelays_pitch_shift_deinit(args[0]);
+    return mp_const_none;
+}
+static MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(audiodelays_pitch_shift___exit___obj, 4, 4, audiodelays_pitch_shift_obj___exit__);
+
+
+//|     semitones: synthio.BlockInput
+//|     """The amount of pitch shifting in semitones (1/12th of an octave)."""
+//|
+static mp_obj_t audiodelays_pitch_shift_obj_get_semitones(mp_obj_t self_in) {
+    audiodelays_pitch_shift_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    return common_hal_audiodelays_pitch_shift_get_semitones(self);
+}
+MP_DEFINE_CONST_FUN_OBJ_1(audiodelays_pitch_shift_get_semitones_obj, audiodelays_pitch_shift_obj_get_semitones);
+
+static mp_obj_t audiodelays_pitch_shift_obj_set_semitones(mp_obj_t self_in, mp_obj_t semitones_in) {
+    audiodelays_pitch_shift_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    common_hal_audiodelays_pitch_shift_set_semitones(self, semitones_in);
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_2(audiodelays_pitch_shift_set_semitones_obj, audiodelays_pitch_shift_obj_set_semitones);
+
+MP_PROPERTY_GETSET(audiodelays_pitch_shift_semitones_obj,
+    (mp_obj_t)&audiodelays_pitch_shift_get_semitones_obj,
+    (mp_obj_t)&audiodelays_pitch_shift_set_semitones_obj);
+
+
+//|     mix: synthio.BlockInput
+//|     """The output mix between 0 and 1 where 0 is only sample and 1 is all effect."""
+static mp_obj_t audiodelays_pitch_shift_obj_get_mix(mp_obj_t self_in) {
+    return common_hal_audiodelays_pitch_shift_get_mix(self_in);
+}
+MP_DEFINE_CONST_FUN_OBJ_1(audiodelays_pitch_shift_get_mix_obj, audiodelays_pitch_shift_obj_get_mix);
+
+static mp_obj_t audiodelays_pitch_shift_obj_set_mix(mp_obj_t self_in, mp_obj_t mix_in) {
+    audiodelays_pitch_shift_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    common_hal_audiodelays_pitch_shift_set_mix(self, mix_in);
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_2(audiodelays_pitch_shift_set_mix_obj, audiodelays_pitch_shift_obj_set_mix);
+
+MP_PROPERTY_GETSET(audiodelays_pitch_shift_mix_obj,
+    (mp_obj_t)&audiodelays_pitch_shift_get_mix_obj,
+    (mp_obj_t)&audiodelays_pitch_shift_set_mix_obj);
+
+
+//|     playing: bool
+//|     """True when the effect is playing a sample. (read-only)"""
+//|
+static mp_obj_t audiodelays_pitch_shift_obj_get_playing(mp_obj_t self_in) {
+    audiodelays_pitch_shift_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    check_for_deinit(self);
+    return mp_obj_new_bool(common_hal_audiodelays_pitch_shift_get_playing(self));
+}
+MP_DEFINE_CONST_FUN_OBJ_1(audiodelays_pitch_shift_get_playing_obj, audiodelays_pitch_shift_obj_get_playing);
+
+MP_PROPERTY_GETTER(audiodelays_pitch_shift_playing_obj,
+    (mp_obj_t)&audiodelays_pitch_shift_get_playing_obj);
+
+
+//|     def play(self, sample: circuitpython_typing.AudioSample, *, loop: bool = False) -> None:
+//|         """Plays the sample once when loop=False and continuously when loop=True.
+//|         Does not block. Use `playing` to block.
+//|
+//|         The sample must match the encoding settings given in the constructor."""
+//|         ...
+//|
+static mp_obj_t audiodelays_pitch_shift_obj_play(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
+    enum { ARG_sample, ARG_loop };
+    static const mp_arg_t allowed_args[] = {
+        { MP_QSTR_sample,    MP_ARG_OBJ | MP_ARG_REQUIRED, {} },
+        { MP_QSTR_loop,      MP_ARG_BOOL | MP_ARG_KW_ONLY, {.u_bool = false} },
+    };
+    audiodelays_pitch_shift_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);
+    check_for_deinit(self);
+    mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
+    mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
+
+    mp_obj_t sample = args[ARG_sample].u_obj;
+    common_hal_audiodelays_pitch_shift_play(self, sample, args[ARG_loop].u_bool);
+
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_KW(audiodelays_pitch_shift_play_obj, 1, audiodelays_pitch_shift_obj_play);
+
+
+//|     def stop(self) -> None:
+//|         """Stops playback of the sample."""
+//|         ...
+//|
+//|
+static mp_obj_t audiodelays_pitch_shift_obj_stop(mp_obj_t self_in) {
+    audiodelays_pitch_shift_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    common_hal_audiodelays_pitch_shift_stop(self);
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_1(audiodelays_pitch_shift_stop_obj, audiodelays_pitch_shift_obj_stop);
+
+
+static const mp_rom_map_elem_t audiodelays_pitch_shift_locals_dict_table[] = {
+    // Methods
+    { MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&audiodelays_pitch_shift_deinit_obj) },
+    { MP_ROM_QSTR(MP_QSTR___enter__), MP_ROM_PTR(&default___enter___obj) },
+    { MP_ROM_QSTR(MP_QSTR___exit__), MP_ROM_PTR(&audiodelays_pitch_shift___exit___obj) },
+    { MP_ROM_QSTR(MP_QSTR_play), MP_ROM_PTR(&audiodelays_pitch_shift_play_obj) },
+    { MP_ROM_QSTR(MP_QSTR_stop), MP_ROM_PTR(&audiodelays_pitch_shift_stop_obj) },
+
+    // Properties
+    { MP_ROM_QSTR(MP_QSTR_playing), MP_ROM_PTR(&audiodelays_pitch_shift_playing_obj) },
+    { MP_ROM_QSTR(MP_QSTR_semitones), MP_ROM_PTR(&audiodelays_pitch_shift_semitones_obj) },
+    { MP_ROM_QSTR(MP_QSTR_mix), MP_ROM_PTR(&audiodelays_pitch_shift_mix_obj) },
+    AUDIOSAMPLE_FIELDS,
+};
+static MP_DEFINE_CONST_DICT(audiodelays_pitch_shift_locals_dict, audiodelays_pitch_shift_locals_dict_table);
+
+static const audiosample_p_t audiodelays_pitch_shift_proto = {
+    MP_PROTO_IMPLEMENT(MP_QSTR_protocol_audiosample)
+    .reset_buffer = (audiosample_reset_buffer_fun)audiodelays_pitch_shift_reset_buffer,
+    .get_buffer = (audiosample_get_buffer_fun)audiodelays_pitch_shift_get_buffer,
+};
+
+MP_DEFINE_CONST_OBJ_TYPE(
+    audiodelays_pitch_shift_type,
+    MP_QSTR_PitchShift,
+    MP_TYPE_FLAG_HAS_SPECIAL_ACCESSORS,
+    make_new, audiodelays_pitch_shift_make_new,
+    locals_dict, &audiodelays_pitch_shift_locals_dict,
+    protocol, &audiodelays_pitch_shift_proto
+    );

shared-bindings/audiodelays/PitchShift.h

@@ -0,0 +1,33 @@
+// This file is part of the CircuitPython project: https://circuitpython.org
+//
+// SPDX-FileCopyrightText: Copyright (c) 2025 Cooper Dalrymple
+//
+// SPDX-License-Identifier: MIT
+
+#pragma once
+
+#include "shared-module/audiodelays/PitchShift.h"
+
+extern const mp_obj_type_t audiodelays_pitch_shift_type;
+
+void common_hal_audiodelays_pitch_shift_construct(audiodelays_pitch_shift_obj_t *self,
+    mp_obj_t semitones, mp_obj_t mix, uint32_t window, uint32_t overlap,
+    uint32_t buffer_size, uint8_t bits_per_sample, bool samples_signed,
+    uint8_t channel_count, uint32_t sample_rate);
+
+void common_hal_audiodelays_pitch_shift_deinit(audiodelays_pitch_shift_obj_t *self);
+bool common_hal_audiodelays_pitch_shift_deinited(audiodelays_pitch_shift_obj_t *self);
+
+uint32_t common_hal_audiodelays_pitch_shift_get_sample_rate(audiodelays_pitch_shift_obj_t *self);
+uint8_t common_hal_audiodelays_pitch_shift_get_channel_count(audiodelays_pitch_shift_obj_t *self);
+uint8_t common_hal_audiodelays_pitch_shift_get_bits_per_sample(audiodelays_pitch_shift_obj_t *self);
+
+mp_obj_t common_hal_audiodelays_pitch_shift_get_semitones(audiodelays_pitch_shift_obj_t *self);
+void common_hal_audiodelays_pitch_shift_set_semitones(audiodelays_pitch_shift_obj_t *self, mp_obj_t semitones);
+
+mp_obj_t common_hal_audiodelays_pitch_shift_get_mix(audiodelays_pitch_shift_obj_t *self);
+void common_hal_audiodelays_pitch_shift_set_mix(audiodelays_pitch_shift_obj_t *self, mp_obj_t arg);
+
+bool common_hal_audiodelays_pitch_shift_get_playing(audiodelays_pitch_shift_obj_t *self);
+void common_hal_audiodelays_pitch_shift_play(audiodelays_pitch_shift_obj_t *self, mp_obj_t sample, bool loop);
+void common_hal_audiodelays_pitch_shift_stop(audiodelays_pitch_shift_obj_t *self);

shared-bindings/audiodelays/__init__.c

@@ -11,6 +11,7 @@
 
 #include "shared-bindings/audiodelays/__init__.h"
 #include "shared-bindings/audiodelays/Echo.h"
+#include "shared-bindings/audiodelays/PitchShift.h"
 
 //| """Support for audio delay effects
 //|
@@ -21,6 +22,7 @@
 static const mp_rom_map_elem_t audiodelays_module_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_audiodelays) },
     { MP_ROM_QSTR(MP_QSTR_Echo), MP_ROM_PTR(&audiodelays_echo_type) },
+    { MP_ROM_QSTR(MP_QSTR_PitchShift), MP_ROM_PTR(&audiodelays_pitch_shift_type) },
 };
 
 static MP_DEFINE_CONST_DICT(audiodelays_module_globals, audiodelays_module_globals_table);