add circuitpython code

1 files changed, 138 insertions, 0 deletions

diff --git a/circuitpython/shared-bindings/synthio/__init__.c b/circuitpython/shared-bindings/synthio/__init__.c
new file mode 100644
index 0000000..72fe2eb
--- /dev/null
+++ b/circuitpython/shared-bindings/synthio/__init__.c
@@ -0,0 +1,138 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021 Artyom Skrobov
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <string.h>
+
+#include "py/mperrno.h"
+#include "py/obj.h"
+#include "py/runtime.h"
+#include "extmod/vfs_fat.h"
+
+#include "shared-bindings/synthio/__init__.h"
+#include "shared-bindings/synthio/MidiTrack.h"
+
+//| """Support for MIDI synthesis"""
+//|
+//| def from_file(file: typing.BinaryIO, *, sample_rate: int = 11025) -> MidiTrack:
+//|     """Create an AudioSample from an already opened MIDI file.
+//|     Currently, only single-track MIDI (type 0) is supported.
+//|
+//|     :param typing.BinaryIO file: Already opened MIDI file
+//|     :param int sample_rate: The desired playback sample rate; higher sample rate requires more memory
+//|
+//|
+//|     Playing a MIDI file from flash::
+//|
+//|           import audioio
+//|           import board
+//|           import synthio
+//|
+//|           data = open("single-track.midi", "rb")
+//|           midi = synthio.from_file(data)
+//|           a = audioio.AudioOut(board.A0)
+//|
+//|           print("playing")
+//|           a.play(midi)
+//|           while a.playing:
+//|             pass
+//|           print("stopped")"""
+//|     ...
+//|
+STATIC mp_obj_t synthio_from_file(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
+    enum { ARG_file, ARG_sample_rate };
+    static const mp_arg_t allowed_args[] = {
+        { MP_QSTR_file, MP_ARG_OBJ | MP_ARG_REQUIRED },
+        { MP_QSTR_sample_rate, MP_ARG_INT | MP_ARG_KW_ONLY, {.u_int = 11025} },
+    };
+    mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
+    mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
+    if (!mp_obj_is_type(args[ARG_file].u_obj, &mp_type_fileio)) {
+        mp_raise_TypeError(translate("file must be a file opened in byte mode"));
+    }
+    pyb_file_obj_t *file = MP_OBJ_TO_PTR(args[ARG_file].u_obj);
+
+    uint8_t chunk_header[14];
+    f_rewind(&file->fp);
+    UINT bytes_read;
+    if (f_read(&file->fp, chunk_header, sizeof(chunk_header), &bytes_read) != FR_OK) {
+        mp_raise_OSError(MP_EIO);
+    }
+    if (bytes_read != sizeof(chunk_header) ||
+        memcmp(chunk_header, "MThd\0\0\0\6\0\0\0\1", 12)) {
+        mp_raise_ValueError(translate("Invalid MIDI file"));
+        // TODO: for a multi-track MIDI (type 1), return an AudioMixer
+    }
+
+    uint16_t tempo;
+    if (chunk_header[12] & 0x80) {
+        tempo = -(int8_t)chunk_header[12] * chunk_header[13];
+    } else {
+        tempo = 2 * ((chunk_header[12] << 8) | chunk_header[13]);
+    }
+
+    if (f_read(&file->fp, chunk_header, 8, &bytes_read) != FR_OK) {
+        mp_raise_OSError(MP_EIO);
+    }
+    if (bytes_read != 8 || memcmp(chunk_header, "MTrk", 4)) {
+        mp_raise_ValueError(translate("Invalid MIDI file"));
+    }
+    uint32_t track_size = (chunk_header[4] << 24) |
+        (chunk_header[5] << 16) | (chunk_header[6] << 8) | chunk_header[7];
+    uint8_t *buffer = m_malloc(track_size, false);
+    if (f_read(&file->fp, buffer, track_size, &bytes_read) != FR_OK) {
+        mp_raise_OSError(MP_EIO);
+    }
+    if (bytes_read != track_size) {
+        mp_raise_ValueError(translate("Invalid MIDI file"));
+    }
+
+    synthio_miditrack_obj_t *result = m_new_obj(synthio_miditrack_obj_t);
+    result->base.type = &synthio_miditrack_type;
+
+    common_hal_synthio_miditrack_construct(result, buffer, track_size,
+        tempo, args[ARG_sample_rate].u_int);
+
+    m_free(buffer);
+
+    return MP_OBJ_FROM_PTR(result);
+}
+MP_DEFINE_CONST_FUN_OBJ_KW(synthio_from_file_obj, 1, synthio_from_file);
+
+
+STATIC const mp_rom_map_elem_t synthio_module_globals_table[] = {
+    { MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_synthio) },
+    { MP_ROM_QSTR(MP_QSTR_MidiTrack), MP_ROM_PTR(&synthio_miditrack_type) },
+    { MP_ROM_QSTR(MP_QSTR_from_file), MP_ROM_PTR(&synthio_from_file_obj) },
+};
+
+STATIC MP_DEFINE_CONST_DICT(synthio_module_globals, synthio_module_globals_table);
+
+const mp_obj_module_t synthio_module = {
+    .base = { &mp_type_module },
+    .globals = (mp_obj_dict_t *)&synthio_module_globals,
+};
+
+MP_REGISTER_MODULE(MP_QSTR_synthio, synthio_module, CIRCUITPY_SYNTHIO);