ref: 2aec1f8a09ae0bc9fb269d84ef53defebc47eede
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()