final report

import sys import pyaudio import math_work import options import psk FORMAT = pyaudio.paInt16 CHANNELS = options.channels RATE = options.rate FREQ = options.freq FREQ_OFF = 0 FRAME_LENGTH = options.frame_length DATASIZE = options.datasize import pdb pdb.set_trace() p = pyaudio.PyAudio() stream = p.open(format=FORMAT, channels=CHANNELS, rate=RATE, output=True) user_input = input if sys.version_info.major >= 3 else raw_input def make_buffer_from_bit_pattern(pattern, on_freq, off_freq): """ Takes a pattern and returns an audio buffer that encodes that pattern """ # the key's middle value is the bit's value and the left and right bits are the bits before and after # the buffers are enveloped to cleanly blend into each other last_bit = pattern[-1] output_buffer = [] offset = 0 for i in range(len(pattern)): bit = pattern[i] if i < len(pattern) - 1: next_bit = pattern[i+1] else: next_bit = pattern[0] freq = on_freq if bit == '1' else off_freq tone = math_work.tone(freq, DATASIZE, offset=offset) output_buffer += math_work.envelope(tone, left=last_bit=='0', right=next_bit=='0') offset += DATASIZE last_bit = bit return math_work.pack_buffer(output_buffer) def play_buffer(buffer): output = b''.join(buffer) stream.write(output) if __name__ == "__main__": print("Welcome. Use ctrl-c to exit") try: # get user input and play message while True: message = user_input("> ") try: pattern = psk.encode(message) buffer = make_buffer_from_bit_pattern(pattern, FREQ, FREQ_OFF) play_buffer(buffer) except KeyError: print("Messages may only contain printable ASCII characters.") except KeyboardInterrupt: # clean up our streams and exit stream.stop_stream() stream.close() p.terminate() print("exited cleanly")