Chorus 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/Chorus.c \
 	shared-bindings/audiodelays/PitchShift.c \
 	shared-bindings/audiodelays/__init__.c \
 	shared-bindings/audiofilters/Distortion.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/Chorus.c \
 	shared-module/audiodelays/PitchShift.c \
 	shared-module/audiodelays/__init__.c \
 	shared-module/audiofilters/Distortion.c \

py/circuitpy_defns.mk

@@ -635,6 +635,7 @@ SRC_SHARED_MODULE_ALL = \
 	audiocore/WaveFile.c \
 	audiocore/__init__.c \
 	audiodelays/Echo.c \
+	audiodelays/Chorus.c \
 	audiodelays/PitchShift.c \
 	audiodelays/__init__.c \
 	audiofilters/Distortion.c \

shared-bindings/audiodelays/Chorus.c

@@ -0,0 +1,278 @@
+// This file is part of the CircuitPython project: https://circuitpython.org
+//
+// SPDX-FileCopyrightText: Copyright (c) 2025 Mark Komus
+//
+// SPDX-License-Identifier: MIT
+
+#include <stdint.h>
+
+#include "shared-bindings/audiodelays/Chorus.h"
+#include "shared-module/audiodelays/Chorus.h"
+#include "shared-bindings/audiocore/__init__.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 Chorus:
+//|     """An Chorus effect"""
+//|
+//|     def __init__(
+//|         self,
+//|         max_delay_ms: int = 50,
+//|         delay_ms: synthio.BlockInput = 50.0,
+//|         voices: synthio.BlockInput = 1.0,
+//|         buffer_size: int = 512,
+//|         sample_rate: int = 8000,
+//|         bits_per_sample: int = 16,
+//|         samples_signed: bool = True,
+//|         channel_count: int = 1,
+//|     ) -> None:
+//|         """Create a Chorus effect by playing the current sample along with one or more samples
+//|            (the voices) from the delay buffer. The voices played are evenly spaced across the delay
+//|            buffer. So for 2 voices you would hear the current sample and the one delay milliseconds back.
+//|            The delay timing of the chorus can be changed at runtime with the delay_ms parameter but the delay
+//|            can never exceed the max_delay_ms parameter. The maximum delay you can set is limited by available
+//|            memory.
+//|
+//|         :param int max_delay_ms: The maximum time the chorus can be in milliseconds
+//|         :param synthio.BlockInput delay_ms: The current time of the chorus delay in milliseconds. Must be less the max_delay_ms.
+//|         :param synthio.BlockInput voices: The number of voices playing split evenly over the delay buffer.
+//|         :param synthio.BlockInput mix: How much of the wet audio to include along with the original signal.
+//|         :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)
+//|
+//|         Playing adding an chorus to a synth::
+//|
+//|           import time
+//|           import board
+//|           import audiobusio
+//|           import synthio
+//|           import audiodelays
+//|
+//|           audio = audiobusio.I2SOut(bit_clock=board.GP20, word_select=board.GP21, data=board.GP22)
+//|           synth = synthio.Synthesizer(channel_count=1, sample_rate=44100)
+//|           chorus = audiodelays.Chorus(max_delay_ms=50, delay_ms=5, buffer_size=1024, channel_count=1, sample_rate=44100)
+//|           chorus.play(synth)
+//|           audio.play(chorus)
+//|
+//|           note = synthio.Note(261)
+//|           while True:
+//|               synth.press(note)
+//|               time.sleep(0.25)
+//|               synth.release(note)
+//|               time.sleep(5)"""
+//|         ...
+//|
+static mp_obj_t audiodelays_chorus_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) {
+    enum { ARG_max_delay_ms, ARG_delay_ms, ARG_voices, ARG_mix, 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_max_delay_ms, MP_ARG_INT | MP_ARG_KW_ONLY, {.u_int = 50 } },
+        { MP_QSTR_delay_ms, MP_ARG_OBJ | MP_ARG_KW_ONLY, {.u_obj = MP_OBJ_NULL} },
+        { MP_QSTR_voices, MP_ARG_OBJ | MP_ARG_KW_ONLY,  {.u_obj = MP_OBJ_NULL} },
+        { MP_QSTR_mix, MP_ARG_OBJ | MP_ARG_KW_ONLY,  {.u_obj = MP_OBJ_NULL} },
+        { 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 max_delay_ms = mp_arg_validate_int_range(args[ARG_max_delay_ms].u_int, 1, 4000, MP_QSTR_max_delay_ms);
+
+    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_chorus_obj_t *self = mp_obj_malloc(audiodelays_chorus_obj_t, &audiodelays_chorus_type);
+    common_hal_audiodelays_chorus_construct(self, max_delay_ms, args[ARG_delay_ms].u_obj, args[ARG_voices].u_obj, args[ARG_mix].u_obj, 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 Chorus."""
+//|         ...
+//|
+static mp_obj_t audiodelays_chorus_deinit(mp_obj_t self_in) {
+    audiodelays_chorus_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    common_hal_audiodelays_chorus_deinit(self);
+    return mp_const_none;
+}
+static MP_DEFINE_CONST_FUN_OBJ_1(audiodelays_chorus_deinit_obj, audiodelays_chorus_deinit);
+
+static void check_for_deinit(audiodelays_chorus_obj_t *self) {
+    audiosample_check_for_deinit(&self->base);
+}
+
+//|     def __enter__(self) -> Chorus:
+//|         """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_chorus_obj___exit__(size_t n_args, const mp_obj_t *args) {
+    (void)n_args;
+    common_hal_audiodelays_chorus_deinit(args[0]);
+    return mp_const_none;
+}
+static MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(audiodelays_chorus___exit___obj, 4, 4, audiodelays_chorus_obj___exit__);
+
+
+//|     delay_ms: synthio.BlockInput
+//|     """The current time of the chorus delay in milliseconds. Must be less the max_delay_ms."""
+//|
+static mp_obj_t audiodelays_chorus_obj_get_delay_ms(mp_obj_t self_in) {
+    audiodelays_chorus_obj_t *self = MP_OBJ_TO_PTR(self_in);
+
+    return common_hal_audiodelays_chorus_get_delay_ms(self);
+}
+MP_DEFINE_CONST_FUN_OBJ_1(audiodelays_chorus_get_delay_ms_obj, audiodelays_chorus_obj_get_delay_ms);
+
+static mp_obj_t audiodelays_chorus_obj_set_delay_ms(mp_obj_t self_in, mp_obj_t delay_ms_in) {
+    audiodelays_chorus_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    common_hal_audiodelays_chorus_set_delay_ms(self, delay_ms_in);
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_2(audiodelays_chorus_set_delay_ms_obj, audiodelays_chorus_obj_set_delay_ms);
+
+MP_PROPERTY_GETSET(audiodelays_chorus_delay_ms_obj,
+    (mp_obj_t)&audiodelays_chorus_get_delay_ms_obj,
+    (mp_obj_t)&audiodelays_chorus_set_delay_ms_obj);
+
+//|     voices: synthio.BlockInput
+//|     """The number of voices playing split evenly over the delay buffer."""
+static mp_obj_t audiodelays_chorus_obj_get_voices(mp_obj_t self_in) {
+    return common_hal_audiodelays_chorus_get_voices(self_in);
+}
+MP_DEFINE_CONST_FUN_OBJ_1(audiodelays_chorus_get_voices_obj, audiodelays_chorus_obj_get_voices);
+
+static mp_obj_t audiodelays_chorus_obj_set_voices(mp_obj_t self_in, mp_obj_t voices_in) {
+    audiodelays_chorus_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    common_hal_audiodelays_chorus_set_voices(self, voices_in);
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_2(audiodelays_chorus_set_voices_obj, audiodelays_chorus_obj_set_voices);
+
+MP_PROPERTY_GETSET(audiodelays_chorus_voices_obj,
+    (mp_obj_t)&audiodelays_chorus_get_voices_obj,
+    (mp_obj_t)&audiodelays_chorus_set_voices_obj);
+
+//|     mix: synthio.BlockInput
+//|     """The rate the echo mix between 0 and 1 where 0 is only sample and 1 is all effect."""
+static mp_obj_t audiodelays_chorus_obj_get_mix(mp_obj_t self_in) {
+    return common_hal_audiodelays_chorus_get_mix(self_in);
+}
+MP_DEFINE_CONST_FUN_OBJ_1(audiodelays_chorus_get_mix_obj, audiodelays_chorus_obj_get_mix);
+
+static mp_obj_t audiodelays_chorus_obj_set_mix(mp_obj_t self_in, mp_obj_t mix_in) {
+    audiodelays_chorus_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    common_hal_audiodelays_chorus_set_mix(self, mix_in);
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_2(audiodelays_chorus_set_mix_obj, audiodelays_chorus_obj_set_mix);
+
+MP_PROPERTY_GETSET(audiodelays_chorus_mix_obj,
+    (mp_obj_t)&audiodelays_chorus_get_mix_obj,
+    (mp_obj_t)&audiodelays_chorus_set_mix_obj);
+
+//|     playing: bool
+//|     """True when the effect is playing a sample. (read-only)"""
+//|
+static mp_obj_t audiodelays_chorus_obj_get_playing(mp_obj_t self_in) {
+    audiodelays_chorus_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    check_for_deinit(self);
+    return mp_obj_new_bool(common_hal_audiodelays_chorus_get_playing(self));
+}
+MP_DEFINE_CONST_FUN_OBJ_1(audiodelays_chorus_get_playing_obj, audiodelays_chorus_obj_get_playing);
+
+MP_PROPERTY_GETTER(audiodelays_chorus_playing_obj,
+    (mp_obj_t)&audiodelays_chorus_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_chorus_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_chorus_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_chorus_play(self, sample, args[ARG_loop].u_bool);
+
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_KW(audiodelays_chorus_play_obj, 1, audiodelays_chorus_obj_play);
+
+//|     def stop(self) -> None:
+//|         """Stops playback of the sample."""
+//|         ...
+//|
+//|
+static mp_obj_t audiodelays_chorus_obj_stop(mp_obj_t self_in) {
+    audiodelays_chorus_obj_t *self = MP_OBJ_TO_PTR(self_in);
+
+    common_hal_audiodelays_chorus_stop(self);
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_1(audiodelays_chorus_stop_obj, audiodelays_chorus_obj_stop);
+
+static const mp_rom_map_elem_t audiodelays_chorus_locals_dict_table[] = {
+    // Methods
+    { MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&audiodelays_chorus_deinit_obj) },
+    { MP_ROM_QSTR(MP_QSTR___enter__), MP_ROM_PTR(&default___enter___obj) },
+    { MP_ROM_QSTR(MP_QSTR___exit__), MP_ROM_PTR(&audiodelays_chorus___exit___obj) },
+    { MP_ROM_QSTR(MP_QSTR_play), MP_ROM_PTR(&audiodelays_chorus_play_obj) },
+    { MP_ROM_QSTR(MP_QSTR_stop), MP_ROM_PTR(&audiodelays_chorus_stop_obj) },
+
+    // Properties
+    { MP_ROM_QSTR(MP_QSTR_playing), MP_ROM_PTR(&audiodelays_chorus_playing_obj) },
+    { MP_ROM_QSTR(MP_QSTR_delay_ms), MP_ROM_PTR(&audiodelays_chorus_delay_ms_obj) },
+    { MP_ROM_QSTR(MP_QSTR_voices), MP_ROM_PTR(&audiodelays_chorus_voices_obj) },
+    { MP_ROM_QSTR(MP_QSTR_mix), MP_ROM_PTR(&audiodelays_chorus_mix_obj) },
+    AUDIOSAMPLE_FIELDS,
+};
+static MP_DEFINE_CONST_DICT(audiodelays_chorus_locals_dict, audiodelays_chorus_locals_dict_table);
+
+static const audiosample_p_t audiodelays_chorus_proto = {
+    MP_PROTO_IMPLEMENT(MP_QSTR_protocol_audiosample)
+    .reset_buffer = (audiosample_reset_buffer_fun)audiodelays_chorus_reset_buffer,
+    .get_buffer = (audiosample_get_buffer_fun)audiodelays_chorus_get_buffer,
+};
+
+MP_DEFINE_CONST_OBJ_TYPE(
+    audiodelays_chorus_type,
+    MP_QSTR_Chorus,
+    MP_TYPE_FLAG_HAS_SPECIAL_ACCESSORS,
+    make_new, audiodelays_chorus_make_new,
+    locals_dict, &audiodelays_chorus_locals_dict,
+    protocol, &audiodelays_chorus_proto
+    );

shared-bindings/audiodelays/Chorus.h

@@ -0,0 +1,36 @@
+// This file is part of the CircuitPython project: https://circuitpython.org
+//
+// SPDX-FileCopyrightText: Copyright (c) 2025 Mark Komus
+//
+// SPDX-License-Identifier: MIT
+
+#pragma once
+
+#include "shared-module/audiodelays/Chorus.h"
+
+extern const mp_obj_type_t audiodelays_chorus_type;
+
+void common_hal_audiodelays_chorus_construct(audiodelays_chorus_obj_t *self, uint32_t max_delay_ms,
+    mp_obj_t delay_ms, mp_obj_t voices, mp_obj_t mix,
+    uint32_t buffer_size, uint8_t bits_per_sample,
+    bool samples_signed, uint8_t channel_count, uint32_t sample_rate);
+
+void common_hal_audiodelays_chorus_deinit(audiodelays_chorus_obj_t *self);
+bool common_hal_audiodelays_chorus_deinited(audiodelays_chorus_obj_t *self);
+
+uint32_t common_hal_audiodelays_chorus_get_sample_rate(audiodelays_chorus_obj_t *self);
+uint8_t common_hal_audiodelays_chorus_get_channel_count(audiodelays_chorus_obj_t *self);
+uint8_t common_hal_audiodelays_chorus_get_bits_per_sample(audiodelays_chorus_obj_t *self);
+
+mp_obj_t common_hal_audiodelays_chorus_get_delay_ms(audiodelays_chorus_obj_t *self);
+void common_hal_audiodelays_chorus_set_delay_ms(audiodelays_chorus_obj_t *self, mp_obj_t delay_ms);
+
+mp_obj_t common_hal_audiodelays_chorus_get_voices(audiodelays_chorus_obj_t *self);
+void common_hal_audiodelays_chorus_set_voices(audiodelays_chorus_obj_t *self, mp_obj_t voices);
+
+mp_obj_t common_hal_audiodelays_chorus_get_mix(audiodelays_chorus_obj_t *self);
+void common_hal_audiodelays_chorus_set_mix(audiodelays_chorus_obj_t *self, mp_obj_t arg);
+
+bool common_hal_audiodelays_chorus_get_playing(audiodelays_chorus_obj_t *self);
+void common_hal_audiodelays_chorus_play(audiodelays_chorus_obj_t *self, mp_obj_t sample, bool loop);
+void common_hal_audiodelays_chorus_stop(audiodelays_chorus_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/Chorus.h"
 #include "shared-bindings/audiodelays/PitchShift.h"
 
 //| """Support for audio delay effects
@@ -22,6 +23,7 @@
 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_Chorus), MP_ROM_PTR(&audiodelays_chorus_type) },
     { MP_ROM_QSTR(MP_QSTR_PitchShift), MP_ROM_PTR(&audiodelays_pitch_shift_type) },
 };