Georg Brandl | 22fff43 | 2009-10-27 20:19:02 +0000 | [diff] [blame] | 1 | #! /usr/bin/env python |
| 2 | |
| 3 | # DAH should be three DOTs. |
| 4 | # Space between DOTs and DAHs should be one DOT. |
| 5 | # Space between two letters should be one DAH. |
| 6 | # Space between two words should be DOT DAH DAH. |
| 7 | |
| 8 | import sys, math, aifc |
| 9 | from contextlib import closing |
| 10 | |
| 11 | DOT = 30 |
| 12 | DAH = 3 * DOT |
| 13 | OCTAVE = 2 # 1 == 441 Hz, 2 == 882 Hz, ... |
| 14 | |
| 15 | morsetab = { |
| 16 | 'A': '.-', 'a': '.-', |
| 17 | 'B': '-...', 'b': '-...', |
| 18 | 'C': '-.-.', 'c': '-.-.', |
| 19 | 'D': '-..', 'd': '-..', |
| 20 | 'E': '.', 'e': '.', |
| 21 | 'F': '..-.', 'f': '..-.', |
| 22 | 'G': '--.', 'g': '--.', |
| 23 | 'H': '....', 'h': '....', |
| 24 | 'I': '..', 'i': '..', |
| 25 | 'J': '.---', 'j': '.---', |
| 26 | 'K': '-.-', 'k': '-.-', |
| 27 | 'L': '.-..', 'l': '.-..', |
| 28 | 'M': '--', 'm': '--', |
| 29 | 'N': '-.', 'n': '-.', |
| 30 | 'O': '---', 'o': '---', |
| 31 | 'P': '.--.', 'p': '.--.', |
| 32 | 'Q': '--.-', 'q': '--.-', |
| 33 | 'R': '.-.', 'r': '.-.', |
| 34 | 'S': '...', 's': '...', |
| 35 | 'T': '-', 't': '-', |
| 36 | 'U': '..-', 'u': '..-', |
| 37 | 'V': '...-', 'v': '...-', |
| 38 | 'W': '.--', 'w': '.--', |
| 39 | 'X': '-..-', 'x': '-..-', |
| 40 | 'Y': '-.--', 'y': '-.--', |
| 41 | 'Z': '--..', 'z': '--..', |
| 42 | '0': '-----', ',': '--..--', |
| 43 | '1': '.----', '.': '.-.-.-', |
| 44 | '2': '..---', '?': '..--..', |
| 45 | '3': '...--', ';': '-.-.-.', |
| 46 | '4': '....-', ':': '---...', |
| 47 | '5': '.....', "'": '.----.', |
| 48 | '6': '-....', '-': '-....-', |
| 49 | '7': '--...', '/': '-..-.', |
| 50 | '8': '---..', '(': '-.--.-', |
| 51 | '9': '----.', ')': '-.--.-', |
| 52 | ' ': ' ', '_': '..--.-', |
| 53 | } |
| 54 | |
| 55 | nowave = b'\0' * 200 |
| 56 | |
| 57 | # If we play at 44.1 kHz (which we do), then if we produce one sine |
| 58 | # wave in 100 samples, we get a tone of 441 Hz. If we produce two |
| 59 | # sine waves in these 100 samples, we get a tone of 882 Hz. 882 Hz |
| 60 | # appears to be a nice one for playing morse code. |
| 61 | def mkwave(octave): |
| 62 | sinewave = bytearray() |
| 63 | for i in range(100): |
| 64 | val = int(math.sin(math.pi * i * octave / 50.0) * 30000) |
| 65 | sinewave.extend([(val >> 8) & 255, val & 255]) |
| 66 | return bytes(sinewave) |
| 67 | |
| 68 | defaultwave = mkwave(OCTAVE) |
| 69 | |
| 70 | def main(): |
| 71 | import getopt |
| 72 | try: |
| 73 | opts, args = getopt.getopt(sys.argv[1:], 'o:p:') |
| 74 | except getopt.error: |
| 75 | sys.stderr.write('Usage ' + sys.argv[0] + |
| 76 | ' [ -o outfile ] [ -p octave ] [ words ] ...\n') |
| 77 | sys.exit(1) |
| 78 | wave = defaultwave |
| 79 | outfile = 'morse.aifc' |
| 80 | for o, a in opts: |
| 81 | if o == '-o': |
| 82 | outfile = a |
| 83 | if o == '-p': |
| 84 | wave = mkwave(int(a)) |
| 85 | with closing(aifc.open(outfile, 'w')) as fp: |
| 86 | fp.setframerate(44100) |
| 87 | fp.setsampwidth(2) |
| 88 | fp.setnchannels(1) |
| 89 | if args: |
| 90 | source = [' '.join(args)] |
| 91 | else: |
| 92 | source = iter(sys.stdin.readline, '') |
| 93 | for line in source: |
| 94 | mline = morse(line) |
| 95 | play(mline, fp, wave) |
| 96 | |
| 97 | # Convert a string to morse code with \001 between the characters in |
| 98 | # the string. |
| 99 | def morse(line): |
| 100 | res = '' |
| 101 | for c in line: |
| 102 | try: |
| 103 | res += morsetab[c] + '\001' |
| 104 | except KeyError: |
| 105 | pass |
| 106 | return res |
| 107 | |
| 108 | # Play a line of morse code. |
| 109 | def play(line, fp, wave): |
| 110 | for c in line: |
| 111 | if c == '.': |
| 112 | sine(fp, DOT, wave) |
| 113 | elif c == '-': |
| 114 | sine(fp, DAH, wave) |
| 115 | else: # space |
| 116 | pause(fp, DAH + DOT) |
| 117 | pause(fp, DOT) |
| 118 | |
| 119 | def sine(fp, length, wave): |
| 120 | for i in range(length): |
| 121 | fp.writeframesraw(wave) |
| 122 | |
| 123 | def pause(fp, length): |
| 124 | for i in range(length): |
| 125 | fp.writeframesraw(nowave) |
| 126 | |
| 127 | if __name__ == '__main__': |
| 128 | main() |