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| 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 | |