Demo/scripts/morse.py

   1 # DAH should be three DOTs.
   2 # Space between DOTs and DAHs should be one DOT.
   3 # Space between two letters should be one DAH.
   4 # Space between two words should be DOT DAH DAH.
   5
   6 import sys, math, audiodev
   7
   8 DOT = 30
   9 DAH = 3 * DOT
  10 OCTAVE = 2                              # 1 == 441 Hz, 2 == 882 Hz, ...
  11
  12 morsetab = {
  13         'A': '.-',              'a': '.-',
  14         'B': '-...',            'b': '-...',
  15         'C': '-.-.',            'c': '-.-.',
  16         'D': '-..',             'd': '-..',
  17         'E': '.',               'e': '.',
  18         'F': '..-.',            'f': '..-.',
  19         'G': '--.',             'g': '--.',
  20         'H': '....',            'h': '....',
  21         'I': '..',              'i': '..',
  22         'J': '.---',            'j': '.---',
  23         'K': '-.-',             'k': '-.-',
  24         'L': '.-..',            'l': '.-..',
  25         'M': '--',              'm': '--',
  26         'N': '-.',              'n': '-.',
  27         'O': '---',             'o': '---',
  28         'P': '.--.',            'p': '.--.',
  29         'Q': '--.-',            'q': '--.-',
  30         'R': '.-.',             'r': '.-.',
  31         'S': '...',             's': '...',
  32         'T': '-',               't': '-',
  33         'U': '..-',             'u': '..-',
  34         'V': '...-',            'v': '...-',
  35         'W': '.--',             'w': '.--',
  36         'X': '-..-',            'x': '-..-',
  37         'Y': '-.--',            'y': '-.--',
  38         'Z': '--..',            'z': '--..',
  39         '0': '-----',
  40         '1': '.----',
  41         '2': '..---',
  42         '3': '...--',
  43         '4': '....-',
  44         '5': '.....',
  45         '6': '-....',
  46         '7': '--...',
  47         '8': '---..',
  48         '9': '----.',
  49         ',': '--..--',
  50         '.': '.-.-.-',
  51         '?': '..--..',
  52         ';': '-.-.-.',
  53         ':': '---...',
  54         "'": '.----.',
  55         '-': '-....-',
  56         '/': '-..-.',
  57         '(': '-.--.-',
  58         ')': '-.--.-',
  59         '_': '..--.-',
  60         ' ': ' '
  61 }
  62
  63 # If we play at 44.1 kHz (which we do), then if we produce one sine
  64 # wave in 100 samples, we get a tone of 441 Hz.  If we produce two
  65 # sine waves in these 100 samples, we get a tone of 882 Hz.  882 Hz
  66 # appears to be a nice one for playing morse code.
  67 def mkwave(octave):
  68         global sinewave, nowave
  69         sinewave = ''
  70         for i in range(100):
  71                 val = int(math.sin(math.pi * float(i) * octave / 50.0) * 30000)
  72                 sinewave = sinewave + chr((val >> 8) & 255) + chr(val & 255)
  73         nowave = '\0' * 200
  74
  75 mkwave(OCTAVE)
  76
  77 def main():
  78         import getopt, string
  79         try:
  80                 opts, args = getopt.getopt(sys.argv[1:], 'o:p:')
  81         except getopt.error:
  82                 sys.stderr.write('Usage ' + sys.argv[0] +
  83                                  ' [ -o outfile ] [ args ] ...\n')
  84                 sys.exit(1)
  85         dev = None
  86         for o, a in opts:
  87                 if o == '-o':
  88                         import aifc
  89                         dev = aifc.open(a, 'w')
  90                         dev.setframerate(44100)
  91                         dev.setsampwidth(2)
  92                         dev.setnchannels(1)
  93                 if o == '-p':
  94                         mkwave(string.atoi(a))
  95         if not dev:
  96                 import audiodev
  97                 dev = audiodev.AudioDev()
  98                 dev.setoutrate(44100)
  99                 dev.setsampwidth(2)
 100                 dev.setnchannels(1)
 101                 dev.close = dev.stop
 102                 dev.writeframesraw = dev.writeframes
 103         if args:
 104                 line = string.join(args)
 105         else:
 106                 line = sys.stdin.readline()
 107         while line:
 108                 mline = morse(line)
 109                 play(mline, dev)
 110                 if hasattr(dev, 'wait'):
 111                         dev.wait()
 112                 if not args:
 113                         line = sys.stdin.readline()
 114                 else:
 115                         line = ''
 116         dev.close()
 117
 118 # Convert a string to morse code with \001 between the characters in
 119 # the string.
 120 def morse(line):
 121         res = ''
 122         for c in line:
 123                 try:
 124                         res = res + morsetab[c] + '\001'
 125                 except KeyError:
 126                         pass
 127         return res
 128
 129 # Play a line of morse code.
 130 def play(line, dev):
 131         for c in line:
 132                 if c == '.':
 133                         sine(dev, DOT)
 134                 elif c == '-':
 135                         sine(dev, DAH)
 136                 else:                   # space
 137                         pause(dev, DAH + DOT)
 138                 pause(dev, DOT)
 139
 140 def sine(dev, length):
 141         for i in range(length):
 142                 dev.writeframesraw(sinewave)
 143
 144 def pause(dev, length):
 145         for i in range(length):
 146                 dev.writeframesraw(nowave)
 147
 148 if __name__ == '__main__' or sys.argv[0] == __name__:
 149         main()