Merged revisions 75337 via svnmerge from

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  r75337 | georg.brandl | 2009-10-11 10:18:44 +0200 (So, 11 Okt 2009) | 1 line

  Update morse script, avoid globals, use iterators.
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Demo/scripts/morse.py

@@ -0,0 +1,128 @@
+#! /usr/bin/env python
+
+# DAH should be three DOTs.
+# Space between DOTs and DAHs should be one DOT.
+# Space between two letters should be one DAH.
+# Space between two words should be DOT DAH DAH.
+
+import sys, math, aifc
+from contextlib import closing
+
+DOT = 30
+DAH = 3 * DOT
+OCTAVE = 2                              # 1 == 441 Hz, 2 == 882 Hz, ...
+
+morsetab = {
+        'A': '.-',              'a': '.-',
+        'B': '-...',            'b': '-...',
+        'C': '-.-.',            'c': '-.-.',
+        'D': '-..',             'd': '-..',
+        'E': '.',               'e': '.',
+        'F': '..-.',            'f': '..-.',
+        'G': '--.',             'g': '--.',
+        'H': '....',            'h': '....',
+        'I': '..',              'i': '..',
+        'J': '.---',            'j': '.---',
+        'K': '-.-',             'k': '-.-',
+        'L': '.-..',            'l': '.-..',
+        'M': '--',              'm': '--',
+        'N': '-.',              'n': '-.',
+        'O': '---',             'o': '---',
+        'P': '.--.',            'p': '.--.',
+        'Q': '--.-',            'q': '--.-',
+        'R': '.-.',             'r': '.-.',
+        'S': '...',             's': '...',
+        'T': '-',               't': '-',
+        'U': '..-',             'u': '..-',
+        'V': '...-',            'v': '...-',
+        'W': '.--',             'w': '.--',
+        'X': '-..-',            'x': '-..-',
+        'Y': '-.--',            'y': '-.--',
+        'Z': '--..',            'z': '--..',
+        '0': '-----',           ',': '--..--',
+        '1': '.----',           '.': '.-.-.-',
+        '2': '..---',           '?': '..--..',
+        '3': '...--',           ';': '-.-.-.',
+        '4': '....-',           ':': '---...',
+        '5': '.....',           "'": '.----.',
+        '6': '-....',           '-': '-....-',
+        '7': '--...',           '/': '-..-.',
+        '8': '---..',           '(': '-.--.-',
+        '9': '----.',           ')': '-.--.-',
+        ' ': ' ',               '_': '..--.-',
+}
+
+nowave = b'\0' * 200
+
+# If we play at 44.1 kHz (which we do), then if we produce one sine
+# wave in 100 samples, we get a tone of 441 Hz.  If we produce two
+# sine waves in these 100 samples, we get a tone of 882 Hz.  882 Hz
+# appears to be a nice one for playing morse code.
+def mkwave(octave):
+    sinewave = bytearray()
+    for i in range(100):
+        val = int(math.sin(math.pi * i * octave / 50.0) * 30000)
+        sinewave.extend([(val >> 8) & 255, val & 255])
+    return bytes(sinewave)
+
+defaultwave = mkwave(OCTAVE)
+
+def main():
+    import getopt
+    try:
+        opts, args = getopt.getopt(sys.argv[1:], 'o:p:')
+    except getopt.error:
+        sys.stderr.write('Usage ' + sys.argv[0] +
+                         ' [ -o outfile ] [ -p octave ] [ words ] ...\n')
+        sys.exit(1)
+    wave = defaultwave
+    outfile = 'morse.aifc'
+    for o, a in opts:
+        if o == '-o':
+            outfile = a
+        if o == '-p':
+            wave = mkwave(int(a))
+    with closing(aifc.open(outfile, 'w')) as fp:
+        fp.setframerate(44100)
+        fp.setsampwidth(2)
+        fp.setnchannels(1)
+        if args:
+            source = [' '.join(args)]
+        else:
+            source = iter(sys.stdin.readline, '')
+        for line in source:
+            mline = morse(line)
+            play(mline, fp, wave)
+
+# Convert a string to morse code with \001 between the characters in
+# the string.
+def morse(line):
+    res = ''
+    for c in line:
+        try:
+            res += morsetab[c] + '\001'
+        except KeyError:
+            pass
+    return res
+
+# Play a line of morse code.
+def play(line, fp, wave):
+    for c in line:
+        if c == '.':
+            sine(fp, DOT, wave)
+        elif c == '-':
+            sine(fp, DAH, wave)
+        else:                   # space
+            pause(fp, DAH + DOT)
+        pause(fp, DOT)
+
+def sine(fp, length, wave):
+    for i in range(length):
+        fp.writeframesraw(wave)
+
+def pause(fp, length):
+    for i in range(length):
+        fp.writeframesraw(nowave)
+
+if __name__ == '__main__':
+    main()