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