# From https://stackoverflow.com/questions/29547218/
# remove-silence-at-the-beginning-and-at-the-end-of-wave-files-with-pydub
from pydub import AudioSegment


def detect_leading_silence(sound, silence_threshold=-50.0, chunk_size=10):
    '''
    sound is a pydub.AudioSegment
    silence_threshold in dB
    chunk_size in ms

    iterate over chunks until you find the first one with sound
    '''
    trim_ms = 0  # ms
    while sound[trim_ms:trim_ms+chunk_size].dBFS < silence_threshold:
        trim_ms += chunk_size

    return trim_ms


if __name__ == '__main__':
    import sys

    sound = AudioSegment.from_file(sys.argv[1], format="wav")

    start_trim = detect_leading_silence(sound)
    end_trim = detect_leading_silence(sound.reverse())

    duration = len(sound)
    trimmed_sound = sound[start_trim:duration-end_trim]
    trimmed_sound.export(sys.argv[1], format="wav")