- initial import

src/bt_signal.py

@@ -0,0 +1,62 @@
+#!/usr/bin/python3
+
+import sys
+import os
+import pathlib
+
+from pydub import silence, AudioSegment
+
+class SignalBoundaries:
+    # Offset from start (in seconds)
+    offset_start: float
+
+    # Offset from finish (in seconds)
+    offset_finish: float
+
+    def __init__(self, offset_start = 0.0, offset_finish = 0.0) -> None:
+        self.offset_start = offset_start
+        self.offset_finish = offset_finish
+
+    def __repr__(self) -> str:
+        return f'[offset_start: {round(self.offset_start, 3)}, offset_finish : {round(self.offset_finish, 3)}]'
+
+
+def find_reference_signal(input_file: pathlib.Path, output_file: pathlib.Path = None, use_end_offset: bool = True) -> SignalBoundaries:
+    myaudio = AudioSegment.from_wav(str(input_file))
+    dBFS = myaudio.dBFS
+    
+    # Find silence intervals
+    intervals = silence.detect_nonsilent(myaudio, min_silence_len=1000, silence_thresh=dBFS-17, seek_step=50)
+    
+    # Translate to seconds
+    intervals = [((start/1000),(stop/1000)) for start,stop in intervals] #in sec
+
+    # print(intervals)
+
+    # Example of intervals: [(5.4, 6.4), (18.7, 37.05)]
+    for p in intervals:
+        if p[1] - p[0] > 17:
+            bounds = SignalBoundaries(offset_start=p[0], offset_finish=p[1])
+            if output_file is not None:
+                signal = myaudio[bounds.offset_start * 1000 : bounds.offset_finish * 1000]
+                signal.export(str(output_file), format='wav', parameters=['-ar', '44100', '-sample_fmt', 's16'])
+
+            if use_end_offset:
+                bounds.offset_finish = myaudio.duration_seconds - bounds.offset_finish
+
+            return bounds
+
+    return SignalBoundaries()
+
+if __name__ == '__main__':
+    if len(sys.argv) < 2:
+        print(f'Please specify input filename.')
+        exit(os.EX_NOINPUT)
+
+    # Output file
+    output_file = pathlib.Path(sys.argv[2]) if len(sys.argv) > 2 else None
+
+    # Input file
+    input_file = sys.argv[1]
+    bounds: SignalBoundaries = find_reference_signal(pathlib.Path(input_file), output_file)
+    print (bounds)