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#! /usr/bin/env python3
# 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()
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