improve midi simplification

simplify_midi_pretty.py

@@ -0,0 +1,58 @@
+import os
+import csv
+# import mido
+import pretty_midi
+from pathlib import Path
+
+CSV_FILE = "test_data/info.csv"
+CSV_FILE_OUT = "test_data/info_simplified.csv"
+base_folder = Path("test_data")
+
+filter_values = (
+    35,  # Acoustic Bass Drum
+    36,  # Bass Drum 1
+    37,  # Side Stick
+    38,  # Acoustic Snare
+    39,  # Hand Clap
+    40,  # Electric Snare
+)
+
+first_midi = None
+outfile = []
+with open(CSV_FILE) as fd:
+    reader = csv.DictReader(fd)
+    for i, row in enumerate(reader):
+        filename = row["midi_filename"]
+        print(f"{i} processing file {filename}...")
+        mid = pretty_midi.PrettyMIDI(str(base_folder/filename))
+        out_mid = pretty_midi.PrettyMIDI(resolution=32)
+        out_track = pretty_midi.Instrument(program=0, is_drum=True)
+        note_length = mid.estimate_tempo() / (60*32)
+
+        for instr in mid.instruments:
+            if not instr.is_drum:
+                continue
+            for note in instr.notes:
+                if note.pitch in filter_values:
+                    out_track.notes.append(
+                        pretty_midi.Note(
+                            velocity=100,
+                            pitch=note.pitch,
+                            start=note.start,
+                            end=note.start + note_length,
+                        )
+                    )
+
+        new_filename = filename.split(".")
+        new_filename.insert(-1, "simplified")
+        new_filename = ".".join(new_filename)
+        out_mid.instruments.append(out_track)
+        out_mid.write(str(base_folder/new_filename))
+        row["simplified_midi_filename"] = new_filename
+        outfile.append(row)
+with open(CSV_FILE_OUT, "w+") as fd:
+    fieldnames = outfile[0].keys()
+
+    writer = csv.DictWriter(fd, fieldnames=fieldnames)
+    writer.writeheader()
+    writer.writerows(outfile)