ref: 1ccd0cd04d75840861e26f6c5f6ac73396d43d8a
dir: /sys/src/cmd/python/Demo/scripts/morse.py/
# 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, audiodev 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': '----.', ',': '--..--', '.': '.-.-.-', '?': '..--..', ';': '-.-.-.', ':': '---...', "'": '.----.', '-': '-....-', '/': '-..-.', '(': '-.--.-', ')': '-.--.-', '_': '..--.-', ' ': ' ' } # 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): global sinewave, nowave sinewave = '' for i in range(100): val = int(math.sin(math.pi * float(i) * octave / 50.0) * 30000) sinewave = sinewave + chr((val >> 8) & 255) + chr(val & 255) nowave = '\0' * 200 mkwave(OCTAVE) def main(): import getopt, string try: opts, args = getopt.getopt(sys.argv[1:], 'o:p:') except getopt.error: sys.stderr.write('Usage ' + sys.argv[0] + ' [ -o outfile ] [ args ] ...\n') sys.exit(1) dev = None for o, a in opts: if o == '-o': import aifc dev = aifc.open(a, 'w') dev.setframerate(44100) dev.setsampwidth(2) dev.setnchannels(1) if o == '-p': mkwave(string.atoi(a)) if not dev: import audiodev dev = audiodev.AudioDev() dev.setoutrate(44100) dev.setsampwidth(2) dev.setnchannels(1) dev.close = dev.stop dev.writeframesraw = dev.writeframes if args: line = string.join(args) else: line = sys.stdin.readline() while line: mline = morse(line) play(mline, dev) if hasattr(dev, 'wait'): dev.wait() if not args: line = sys.stdin.readline() else: line = '' dev.close() # Convert a string to morse code with \001 between the characters in # the string. def morse(line): res = '' for c in line: try: res = res + morsetab[c] + '\001' except KeyError: pass return res # Play a line of morse code. def play(line, dev): for c in line: if c == '.': sine(dev, DOT) elif c == '-': sine(dev, DAH) else: # space pause(dev, DAH + DOT) pause(dev, DOT) def sine(dev, length): for i in range(length): dev.writeframesraw(sinewave) def pause(dev, length): for i in range(length): dev.writeframesraw(nowave) if __name__ == '__main__' or sys.argv[0] == __name__: main()