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import fluidsynth |
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import numpy as np |
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def synthesis(midi_opus, soundfont_path, sample_rate=44100): |
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ticks_per_beat = midi_opus[0] |
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event_list = [] |
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for track_idx, track in enumerate(midi_opus[1:]): |
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abs_t = 0 |
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for event in track: |
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abs_t += event[1] |
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event_new = [*event] |
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event_new[1] = abs_t |
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event_list.append(event_new) |
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event_list = sorted(event_list, key=lambda e: e[1]) |
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tempo = int((60 / 120) * 10 ** 6) |
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ss = np.empty((0, 2), dtype=np.int16) |
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fl = fluidsynth.Synth(samplerate=float(sample_rate)) |
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sfid = fl.sfload(soundfont_path) |
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last_t = 0 |
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for c in range(16): |
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fl.program_select(c, sfid, 128 if c == 9 else 0, 0) |
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for event in event_list: |
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name = event[0] |
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sample_len = int(((event[1] / ticks_per_beat) * tempo / (10 ** 6)) * sample_rate) |
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sample_len -= int(((last_t / ticks_per_beat) * tempo / (10 ** 6)) * sample_rate) |
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last_t = event[1] |
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if sample_len > 0: |
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sample = fl.get_samples(sample_len).reshape(sample_len, 2) |
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ss = np.concatenate([ss, sample]) |
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if name == "set_tempo": |
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tempo = event[2] |
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elif name == "patch_change": |
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c, p = event[2:4] |
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fl.program_select(c, sfid, 128 if c == 9 else 0, p) |
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elif name == "control_change": |
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c, cc, v = event[2:5] |
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fl.cc(c, cc, v) |
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elif name == "note_on" and event[3] > 0: |
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c, p, v = event[2:5] |
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fl.noteon(c, p, v) |
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elif name == "note_off" or (name == "note_on" and event[3] == 0): |
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c, p = event[2:4] |
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fl.noteoff(c, p) |
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fl.delete() |
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if ss.shape[0] > 0: |
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max_val = np.abs(ss).max() |
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if max_val != 0: |
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ss = (ss / max_val) * np.iinfo(np.int16).max |
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ss = ss.astype(np.int16) |
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return ss |
