217 lines
7.7 KiB
C
217 lines
7.7 KiB
C
/*
|
|
* This file is part of the Micro Python 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 "py/runtime.h"
|
|
#include "shared-bindings/synthio/MidiTrack.h"
|
|
|
|
#define LOUDNESS 0x4000 // 0.5
|
|
#define BITS_PER_SAMPLE 16
|
|
#define BYTES_PER_SAMPLE (BITS_PER_SAMPLE / 8)
|
|
#define SILENCE 0x80
|
|
|
|
STATIC NORETURN void raise_midi_stream_error(uint32_t pos) {
|
|
mp_raise_ValueError_varg(translate("Error in MIDI stream at position %d"), pos);
|
|
}
|
|
|
|
STATIC uint8_t parse_note(const uint8_t *buffer, uint32_t len, uint32_t *pos) {
|
|
if (*pos + 1 >= len) {
|
|
raise_midi_stream_error(*pos);
|
|
}
|
|
uint8_t note = buffer[(*pos)++];
|
|
if (note > 127 || buffer[(*pos)++] > 127) {
|
|
raise_midi_stream_error(*pos);
|
|
}
|
|
return note;
|
|
}
|
|
|
|
STATIC void terminate_span(synthio_miditrack_obj_t *self, uint16_t *dur, uint16_t *max_dur) {
|
|
if (*dur) {
|
|
self->track[self->total_spans - 1].dur = *dur;
|
|
if (*dur > *max_dur) {
|
|
*max_dur = *dur;
|
|
}
|
|
*dur = 0;
|
|
} else {
|
|
self->total_spans--;
|
|
}
|
|
}
|
|
|
|
STATIC void add_span(synthio_miditrack_obj_t *self, uint8_t note1, uint8_t note2) {
|
|
synthio_midi_span_t span = { 0, {note1, note2} };
|
|
self->track = m_realloc(self->track,
|
|
(self->total_spans + 1) * sizeof(synthio_midi_span_t));
|
|
self->track[self->total_spans++] = span;
|
|
}
|
|
|
|
void common_hal_synthio_miditrack_construct(synthio_miditrack_obj_t *self,
|
|
const uint8_t *buffer, uint32_t len, uint32_t tempo, uint32_t sample_rate) {
|
|
|
|
synthio_midi_span_t initial = { 0, {SILENCE, SILENCE} };
|
|
self->sample_rate = sample_rate;
|
|
self->track = m_malloc(sizeof(synthio_midi_span_t), false);
|
|
self->next_span = 0;
|
|
self->total_spans = 1;
|
|
*self->track = initial;
|
|
|
|
uint16_t dur = 0, max_dur = 0;
|
|
uint32_t pos = 0;
|
|
while (pos < len) {
|
|
uint8_t c;
|
|
uint32_t delta = 0;
|
|
do {
|
|
c = buffer[pos++];
|
|
delta <<= 7;
|
|
delta |= c & 0x7f;
|
|
} while ((c & 0x80) && (pos < len));
|
|
|
|
if (c & 0x80) {
|
|
raise_midi_stream_error(pos);
|
|
}
|
|
|
|
dur += delta * sample_rate / tempo;
|
|
|
|
switch (buffer[pos++] >> 4) {
|
|
case 8: { // Note Off
|
|
uint8_t note = parse_note(buffer, len, &pos);
|
|
|
|
// Ignore if not a note which is playing
|
|
synthio_midi_span_t last_span = self->track[self->total_spans - 1];
|
|
if (last_span.note[0] == note || last_span.note[1] == note) {
|
|
terminate_span(self, &dur, &max_dur);
|
|
if (last_span.note[0] == note) {
|
|
add_span(self, last_span.note[1], SILENCE);
|
|
} else {
|
|
add_span(self, last_span.note[0], SILENCE);
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
case 9: { // Note On
|
|
uint8_t note = parse_note(buffer, len, &pos);
|
|
|
|
// Ignore if two notes are already playing
|
|
synthio_midi_span_t last_span = self->track[self->total_spans - 1];
|
|
if (last_span.note[1] == SILENCE) {
|
|
terminate_span(self, &dur, &max_dur);
|
|
if (last_span.note[0] == SILENCE) {
|
|
add_span(self, note, SILENCE);
|
|
} else {
|
|
add_span(self, last_span.note[0], note);
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
case 10:
|
|
case 11:
|
|
case 14: // two data bytes to ignore
|
|
parse_note(buffer, len, &pos);
|
|
break;
|
|
case 12:
|
|
case 13: // one data byte to ignore
|
|
if (pos >= len || buffer[pos++] > 127) {
|
|
raise_midi_stream_error(pos);
|
|
}
|
|
break;
|
|
case 15: // the full syntax is too complicated, just assume it's "End of Track" event
|
|
pos = len;
|
|
break;
|
|
default: // invalid event
|
|
raise_midi_stream_error(pos);
|
|
}
|
|
}
|
|
terminate_span(self, &dur, &max_dur);
|
|
|
|
self->buffer_length = max_dur * BYTES_PER_SAMPLE;
|
|
self->buffer = m_malloc(self->buffer_length, false);
|
|
}
|
|
|
|
void common_hal_synthio_miditrack_deinit(synthio_miditrack_obj_t *self) {
|
|
m_free(self->buffer);
|
|
self->buffer = NULL;
|
|
m_free(self->track);
|
|
self->track = NULL;
|
|
}
|
|
bool common_hal_synthio_miditrack_deinited(synthio_miditrack_obj_t *self) {
|
|
return self->buffer == NULL;
|
|
}
|
|
|
|
uint32_t common_hal_synthio_miditrack_get_sample_rate(synthio_miditrack_obj_t *self) {
|
|
return self->sample_rate;
|
|
}
|
|
uint8_t common_hal_synthio_miditrack_get_bits_per_sample(synthio_miditrack_obj_t *self) {
|
|
return BITS_PER_SAMPLE;
|
|
}
|
|
uint8_t common_hal_synthio_miditrack_get_channel_count(synthio_miditrack_obj_t *self) {
|
|
return 1;
|
|
}
|
|
|
|
void synthio_miditrack_reset_buffer(synthio_miditrack_obj_t *self,
|
|
bool single_channel_output, uint8_t channel) {
|
|
|
|
self->next_span = 0;
|
|
}
|
|
|
|
STATIC const uint16_t notes[] = {8372, 8870, 9397, 9956, 10548, 11175, 11840,
|
|
12544, 13290, 14080, 14917, 15804}; // 9th octave
|
|
|
|
audioio_get_buffer_result_t synthio_miditrack_get_buffer(synthio_miditrack_obj_t *self,
|
|
bool single_channel_output, uint8_t channel, uint8_t **buffer, uint32_t *buffer_length) {
|
|
|
|
if (self->next_span >= self->total_spans) {
|
|
*buffer_length = 0;
|
|
return GET_BUFFER_DONE;
|
|
}
|
|
|
|
synthio_midi_span_t span = self->track[self->next_span++];
|
|
*buffer_length = span.dur * BYTES_PER_SAMPLE;
|
|
uint8_t octave1 = span.note[0] / 12; // 0..10
|
|
uint8_t octave2 = span.note[1] / 12; // 0..10
|
|
int32_t base_freq1 = notes[span.note[0] % 12];
|
|
int32_t base_freq2 = notes[span.note[1] % 12];
|
|
int32_t sample_rate = self->sample_rate;
|
|
|
|
for (uint16_t i = 0; i < span.dur; i++) {
|
|
int16_t semiperiod1 = span.note[0] == SILENCE ? 0 :
|
|
((base_freq1 * i * 2) / sample_rate) >> (10 - octave1);
|
|
int16_t semiperiod2 = span.note[1] == SILENCE ? semiperiod1 :
|
|
((base_freq2 * i * 2) / sample_rate) >> (10 - octave2);
|
|
self->buffer[i] = ((semiperiod1 % 2 + semiperiod2 % 2) - 1) * LOUDNESS;
|
|
}
|
|
*buffer = (uint8_t *)self->buffer;
|
|
|
|
return self->next_span >= self->total_spans ?
|
|
GET_BUFFER_DONE : GET_BUFFER_MORE_DATA;
|
|
}
|
|
|
|
void synthio_miditrack_get_buffer_structure(synthio_miditrack_obj_t *self, bool single_channel_output,
|
|
bool *single_buffer, bool *samples_signed, uint32_t *max_buffer_length, uint8_t *spacing) {
|
|
|
|
*single_buffer = true;
|
|
*samples_signed = true;
|
|
*max_buffer_length = self->buffer_length;
|
|
*spacing = 1;
|
|
}
|