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Don't require huge buffers for long-held notes

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This commit is contained in:
Jeff Epler 2023-03-31 16:41:05 -05:00
parent 7f73ff1b2d
commit db1e01c462
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GPG Key ID: D5BF15AB975AB4DE
2 changed files with 21 additions and 11 deletions
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29
shared-module/synthio/MidiTrack.c
View File

@ -27,9 +27,10 @@
#include "py/runtime.h"
#include "shared-bindings/synthio/MidiTrack.h"
#define BITS_PER_SAMPLE 16
#define BITS_PER_SAMPLE (16)
#define BYTES_PER_SAMPLE (BITS_PER_SAMPLE / 8)
#define SILENCE 0x80
#define MAX_DUR (512)
#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);
@ -77,6 +78,7 @@ STATIC void change_span_note(synthio_miditrack_obj_t *self, uint8_t old_note, ui
terminate_span(self, dur);
span.note[channel] = new_note;
add_span(self, &span);
*dur = 0;
}
}
@ -144,7 +146,7 @@ void common_hal_synthio_miditrack_construct(synthio_miditrack_obj_t *self,
for (int i = 0; i < self->total_spans; i++) {
max_dur = MAX(self->track[i].dur, max_dur);
}
self->buffer_length = max_dur * BYTES_PER_SAMPLE;
self->buffer_length = MIN(MAX_DUR, max_dur) * BYTES_PER_SAMPLE;
self->buffer = m_malloc(self->buffer_length, false);
}
@ -171,6 +173,7 @@ uint8_t common_hal_synthio_miditrack_get_channel_count(synthio_miditrack_obj_t *
void synthio_miditrack_reset_buffer(synthio_miditrack_obj_t *self,
bool single_channel_output, uint8_t channel) {
self->remaining_dur = 0;
self->next_span = 0;
}
@ -189,14 +192,20 @@ static int count_active_channels(synthio_midi_span_t *span) {
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) {
synthio_midi_span_t span = self->track[self->next_span - !!self->remaining_dur];
if (self->next_span >= self->total_spans) {
*buffer_length = 0;
return GET_BUFFER_DONE;
if (self->remaining_dur == 0) {
if (self->next_span >= self->total_spans) {
*buffer_length = 0;
return GET_BUFFER_DONE;
}
self->next_span++;
self->remaining_dur = span.dur;
}
synthio_midi_span_t span = self->track[self->next_span++];
*buffer_length = span.dur * BYTES_PER_SAMPLE;
uint16_t dur = MIN(MAX_DUR, self->remaining_dur);
self->remaining_dur -= dur;
*buffer_length = dur * BYTES_PER_SAMPLE;
memset(self->buffer, 0, *buffer_length);
int32_t sample_rate = self->sample_rate;
@ -212,7 +221,7 @@ audioio_get_buffer_result_t synthio_miditrack_get_buffer(synthio_miditrack_obj_t
uint16_t base_freq = notes[span.note[chan] % 12];
uint32_t accum = self->accum[chan];
uint32_t rate = base_freq * 2;
for (uint16_t i = 0; i < span.dur; i++) {
for (uint16_t i = 0; i < dur; i++) {
accum += rate;
int16_t semiperiod = (accum / sample_rate) >> (10 - octave);
self->buffer[i] += semiperiod % 2 ? loudness : -loudness;
@ -223,7 +232,7 @@ audioio_get_buffer_result_t synthio_miditrack_get_buffer(synthio_miditrack_obj_t
*buffer = (uint8_t *)self->buffer;
return self->next_span >= self->total_spans ?
return (self->remaining_dur == 0 && self->next_span >= self->total_spans) ?
GET_BUFFER_DONE : GET_BUFFER_MORE_DATA;
}

3
shared-module/synthio/MidiTrack.h
View File

@ -41,10 +41,11 @@ typedef struct {
uint32_t sample_rate;
uint16_t *buffer;
uint16_t buffer_length;
synthio_midi_span_t *track;
uint16_t remaining_dur;
uint16_t next_span;
uint16_t total_spans;
uint32_t accum[CIRCUITPY_SYNTHIO_MAX_CHANNELS];
synthio_midi_span_t *track;
} synthio_miditrack_obj_t;