def transcribe(decoder, audio_file, libdir=None):
    """ Decode streaming audio data from raw binary file on disk. """
    decoder = get_decoder()

    decoder.start_utt()
    stream = open(audio_file, 'rb')
    while True:
        buf = stream.read(1024)
        if buf:
            decoder.process_raw(buf, False, False)
        else:
            break
    decoder.end_utt()
    return evaluate_results(decoder)
Decode streaming audio data from raw binary file on disk.