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#!/usr/bin/env python
import sys, wave
class modem:
# Modem specific constants
bits = [[3 * chr(0), 5 * chr(0)], [3 * chr(255), 5 * chr(255)]]
sync = [17 * chr(0), 17 * chr(255)]
# Variable to alternate high and low
hilo = 0
supportedFrequencies = [16000,22050,24000,32000,44100,48000]
cnt = 0
# Data variables
data = []
parity = True
frequency = 48000
# Hamming code translation table
_hammingCalculateParityLowNibble = [0, 3, 5, 6, 6, 5, 3, 0, 7, 4, 2, 1, 1, 2, 4, 7]
_hammingCalculateParityHighNibble = [0, 9, 10, 3, 11, 2, 1, 8, 12, 5, 6, 15, 7, 14, 13, 4]
# Almost nothing here
def __init__(self, data=[], parity=True, frequency=48000):
self.data = data
self.parity = parity
self.frequency = frequency if frequency in self.supportedFrequencies else 48000
# Calculate Hamming parity for 12,8 code (12 bit of which 8bit data)
def hammingCalculateParity128(self, byte):
return self._hammingCalculateParityLowNibble[byte&0x0F] ^ self._hammingCalculateParityHighNibble[byte >> 4]
# Calculate Hamming parity for 24,16 code (24 bit of which 16 bit are data)
def hammingCalculateParity2416(self, first, second):
return self.hammingCalculateParity128(second) << 4 | self.hammingCalculateParity128(first)
# Generate one sync-pulse
def syncsignal(self):
self.hilo ^= 1
return self.sync[self.hilo]
# Generate a number of sync signals
def generateSyncSignal(self, number):
sound = ""
for i in xrange(number):
sound += self.syncsignal()
return sound
# Decode bits to modem signals
def modemcode(self, byte):
bleep = ""
for x in xrange(8):
self.hilo ^= 1
bleep += self.bits[self.hilo][byte & 0x01]
byte >>= 1
return bleep
# Return <length> samples of silence
def silence(self, length):
return chr(127) * length
# Set data for modem code
def setData(self, data):
self.data = data
# Set whether to use parity or not
def setParity(self, parity):
self.parity = parity
# Set the frequency for the audio
def setFrequency(self, frequency):
self.frequency = frequency if frequency in self.supportedFrequencies else 48000
# Generates the audio frames based on the data
def generateAudioFrames(self):
if self.parity:
tmpdata = []
# for uneven length data, we have to append a null byte
if not len(self.data) % 2 == 0:
self.data.append(chr(0))
# insert the parity information every two bytes, sorry for the heavy casting
for index in range(0, len(self.data), 2):
tmpdata.extend(self.data[index:index+2])
tmpdata.append(chr(self.hammingCalculateParity2416(ord(self.data[index]),ord(self.data[index+1]))))
self.data = tmpdata
# generate the audio itself
# add some sync signal in front
sound = self.generateSyncSignal(4)
# process the data and insert sync signal every 10 bytes
for byte in self.data:
sound += self.modemcode(ord(byte))
self.cnt += 1
if self.cnt == 10:
sound += self.generateSyncSignal(2)
self.cnt = 0
# add some sync signals in the end
sound += self.generateSyncSignal(4)
return sound
def saveAudio(self,filename):
wav = wave.open(filename, 'wb')
wav.setparams((1, 1, self.frequency, 0, "NONE", None))
wav.writeframes(self.generateAudioFrames())
wav.close()
class Frame( object ):
""" Returns the frame information """
def getFrameHeader(self):
raise NotImplementedError("You should implement this!")
""" Returns the representation """
def getRepresentation(self):
raise NotImplementedError("Should have implemented this")
class textFrame(Frame):
text = ""
speed = 0
delay = 0
direction = 0
# identifier as of message specification: 0001
identifier = 0x01
def __init__(self,text,speed=1,delay=0,direction=0):
self.text = text
self.setSpeed(speed)
self.setDelay(delay)
self.setDirection(direction)
def setSpeed(self,speed):
self.speed = speed if speed < 16 else 1
def setDelay(self,delay):
self.delay = delay if delay < 16 else 0
def setDirection(self,direction):
self.direction = direction if direction in [0,1] else 0
# Frame header: 4 bit type + 12 bit length
def getFrameHeader(self):
return [chr(self.identifier << 4 | len(self.text) >> 8), chr(len(self.text) & 0xFF) ]
# Header -> 4bit speed, 4 bit delay, 4 bit direction, 4 bit zero
def getHeader(self):
return [chr(self.speed << 4 | self.delay), chr(self.direction << 4 | 0x00)]
def getRepresentation(self):
retval = []
retval.extend(self.getFrameHeader())
retval.extend(self.getHeader())
retval.extend(list(self.text))
return retval
class animationFrame(Frame):
animation = []
speed = 0
delay = 0
# identifier as per specification: 0010
identifier = 0x02
def __init__(self,animation,speed=1,delay=0):
self.setAnimation(animation)
self.setSpeed(speed)
self.setDelay(delay)
def setAnimation(self,animation):
if len(animation) % 8 is not 0:
raise Exception
else:
self.animation = animation
def setSpeed(self,speed):
self.speed = speed if speed < 16 else 1
def setDelay(self,delay):
self.delay = delay if delay < 16 else 0
# Frame header: 4 bit type + 12 bit length
def getFrameHeader(self):
return [chr(self.identifier << 4 | len(self.animation) >> 8), chr(len(self.animation) & 0xFF) ]
# Header -> 4bit zero, 4bit speed, 4 bit zero, 4 bit direction
def getHeader(self):
return [chr(self.speed), chr(self.delay)]
def getRepresentation(self):
retval = []
retval.extend(self.getFrameHeader())
retval.extend(self.getHeader())
retval.extend(self.animation)
return retval
class blinkenrocket():
eeprom_size = 65536
startcode = chr(0x99)
patterncode = chr(0xA9)
frames = []
def __init__(self,eeprom_size=65536):
self.eeprom_size = eeprom_size if eeprom_size < 256*1024*1024 else 65536
def addFrame(self, frame):
if not isinstance(frame, Frame):
raise RuntimeError("Incorrect frame supplied")
else:
self.frames.append(frame)
def getMessage(self):
output = [self.startcode, self.startcode]
for frame in self.frames:
output.extend([self.patterncode,self.patterncode])
output.extend(frame.getRepresentation())
return output
if __name__ == '__main__':
m = modem(parity=True)
#print list(open(sys.argv[1]).read())
m.setData(list(open(sys.argv[1]).read()))
m.saveAudio(sys.argv[2])
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