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| -rwxr-xr-x | Demo/scripts/morse.py | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/Demo/scripts/morse.py b/Demo/scripts/morse.py new file mode 100755 index 0000000..5aacaa1 --- /dev/null +++ b/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() |