midi-composer / midi_synthesizer.py
skytnt's picture
Update midi_synthesizer.py
5b21cca
raw
history blame
2.19 kB
import fluidsynth
import numpy as np
def synthesis(midi_opus, soundfont_path, sample_rate=44100):
ticks_per_beat = midi_opus[0]
tempo = int((60 / 140) * 10 ** 6) # default 140 bpm
fl = fluidsynth.Synth(samplerate=float(sample_rate))
sfid = fl.sfload(soundfont_path)
waveforms = []
for track_idx, track in enumerate(midi_opus[1:]):
ss = np.empty((0, 2), dtype=np.int16)
cur_t = 0
last_t = 0
fl.system_reset()
fl.get_samples(int(2 * sample_rate)) # get 2 seconds sample to eliminate reverb sound from previous track
for c in range(16):
fl.program_select(c, sfid, 128 if c == 9 else 0, 0)
for event in track:
name = event[0]
cur_t += event[1]
sample_len = int(((cur_t / ticks_per_beat) * tempo / (10 ** 6)) * sample_rate)
sample_len -= int(((last_t / ticks_per_beat) * tempo / (10 ** 6)) * sample_rate)
last_t = cur_t
if sample_len > 0:
sample = fl.get_samples(sample_len).reshape(sample_len, 2)
ss = np.concatenate([ss, sample])
if name == "set_tempo":
tempo = event[2]
elif name == "patch_change":
c, p = event[2:4]
fl.program_select(c, sfid, 128 if c == 9 else 0, p)
elif name == "control_change":
c, cc, v = event[2:5]
fl.cc(c, cc, v)
elif name == "note_on" and event[3] > 0:
c, p, v = event[2:5]
fl.noteon(c, p, v)
elif name == "note_off" or (name == "note_on" and event[3] == 0):
c, p = event[2:4]
fl.noteoff(c, p)
waveforms.append(ss)
fl.delete()
synthesized = np.zeros((max([w.shape[0] for w in waveforms]), 2), dtype=np.int32)
for waveform in waveforms:
synthesized[:waveform.shape[0]] += waveform
if synthesized.shape[0] > 0:
max_val = np.abs(synthesized).max()
if max_val != 0:
synthesized = (synthesized / max_val) * np.iinfo(np.int16).max
synthesized = synthesized.astype(np.int16)
return synthesized