Mac/Demo/sound/morselib.py

"""Translate text strings to Morse code"""

FRAMERATE = 22050
SAMPWIDTH = 2

BASEFREQ = 441
OCTAVE = 2

DOT = 30
DAH = 80

morsetab = {
	'a': '.-',
	'b': '-...',
	'c': '-.-.',
	'd': '-..',
	'e': '.',
	'f': '..-.',
	'g': '--.',
	'h': '....',
	'i': '..',
	'j': '.---',
	'k': '-.-',
	'l': '.-..',
	'm': '--',
	'n': '-.',
	'o': '---',
	'p': '.--.',
	'q': '--.-',
	'r': '.-.',
	's': '...',
	't': '-',
	'u': '..-',
	'v': '...-',
	'w': '.--',
	'x': '-..-',
	'y': '-.--',
	'z': '--..',
	'0': '-----',
	'1': '.----',
	'2': '..---',
	'3': '...--',
	'4': '....-',
	'5': '.....',
	'6': '-....',
	'7': '--...',
	'8': '---..',
	'9': '----.',
	',': '--..--',
	'.': '.-.-.-',
	'?': '..--..',
	';': '-.-.-.',
	':': '---...',
	"'": '.----.',
	'-': '-....-',
	'/': '-..-.',
	'(': '-.--.-',
	')': '-.--.-', # XXX same as code for '(' ???
	'_': '..--.-',
	' ': ' '
}

def morsecode(s):
	from string import lower
	m = ''
	for c in s:
		c = lower(c)
		if morsetab.has_key(c):
			c = morsetab[c] + ' '
		else:
			c = '? '
		m = m + c
	return m


class BaseMorse:
	"base class for morse transmissions" 
	
	def __init__(self):
		"constructor"
		self.dots = DOT
		self.dahs = DAH
	
	def noise(self, duration):
		"beep for given duration"
		pass
	
	def pause(self, duration):
		"pause for given duration"
		pass
	
	def dot(self):
		"short beep"
		self.noise(self.dots)
	
	def dah(self):
		"long beep"
		self.noise(self.dahs)
	
	def pdot(self):
		"pause as long as a dot"
		self.pause(self.dots)
	
	def pdah(self):
		"pause as long as a dah"
		self.pause(self.dahs)
	
	def sendmorse(self, s):
		for c in s:
			if c == '.': self.dot()
			elif c == '-': self.dah()
			else: self.pdah()
			self.pdot()
	
	def sendascii(self, s):
		self.sendmorse(morsecode(s))
	
	def send(self, s):
		self.sendascii(s)


import Audio_mac
class MyAudio(Audio_mac.Play_Audio_mac):
	def _callback(self, *args):
		if hasattr(self, 'usercallback'): self.usercallback()
		apply(Audio_mac.Play_Audio_mac._callback, (self,) + args)


class MacMorse(BaseMorse):
	"Mac specific class to play Morse code"
	
	def __init__(self):
		BaseMorse.__init__(self)
		self.dev = MyAudio()
		self.dev.setoutrate(FRAMERATE)
		self.dev.setsampwidth(SAMPWIDTH)
		self.dev.setnchannels(1)
		self.dev.usercallback = self.usercallback
		sinewave = ''
		n = int(FRAMERATE / BASEFREQ)
		octave = OCTAVE
		from math import sin, pi
		for i in range(n):
			val = int(sin(2 * pi * i * octave / n) * 0x7fff)
			sample = chr((val >> 8) & 255) + chr(val & 255)
			sinewave = sinewave + sample[:SAMPWIDTH]
		self.sinewave = sinewave
		self.silence = '\0' * (n*SAMPWIDTH)
		self.morsequeue = ''
	
	def __del__(self):
		self.close()
	
	def close(self):
		self.dev = None
	
	def pause(self, duration):
		self.dev.writeframes(self.silence * duration)
	
	def noise(self, duration):
		self.dev.writeframes(self.sinewave * duration)
	
	def sendmorse(self, s):
		self.morsequeue = self.morsequeue + s
		self.dev.usercallback()
		self.dev.usercallback()
		self.dev.usercallback()
	
	def usercallback(self):
		if self.morsequeue:
			c, self.morsequeue = self.morsequeue[0], self.morsequeue[1:]
			if c == '.': self.dot()
			elif c == '-': self.dah()
			else: self.pdah()
			self.pdot()


def test():
	m = MacMorse()
	while 1:
		try:
			line = raw_input('Morse line: ')
		except (EOFError, KeyboardInterrupt):
			break
		m.send(line)
		while m.morsequeue: pass

test()