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()