Update midi_synthesizer.py

midi_synthesizer.py

@@ -45,4 +45,9 @@ def synthesis(midi_opus, soundfont_path, sample_rate=44100):
             fl.noteoff(c, p)
 
     fl.delete()
+    if ss.shape[0] > 0:
+        max_val = np.abs(ss).max()
+        if max_val != 0:
+            ss = (ss / max_val) * np.iinfo(np.int16).max
+    ss = ss.astype(np.int16)
     return ss