import sys

SECTOR_SIZE = 512
cr2_header  = '49492a001000000043520200'
wav_header  = '52494646'
jpeg_header = 'ffd8ffe'

class RecoverImages:
	outfile = ""
	extension = ""
	file_number = ""

	def __init__(self, filename):
		self.extension = "junk"
		self.outfile = 0
		self.file_number = 0
		self.recover(filename)
		
	def recover(self, in_filename):
		data=open(in_filename, 'rb')
		self.update_output_file()
		sector = data.read(SECTOR_SIZE)
		while(sector):
			if(self.detected_start_of_file(sector)):
				self.file_number = self.file_number + 1
				self.update_output_file()
			
			self.outfile.write(sector)
			sector = data.read(SECTOR_SIZE)

		data.close()

	def update_output_file(self):
		if(self.outfile):
			self.outfile.close()
		out_filename = "saved_%03d.%s" % (self.file_number, self.extension)
		self.outfile = open(out_filename, 'wb')
		print out_filename
	
	def detected_start_of_file(self, sector):
		result = False;
		header = sector[0:12]
		headerhex = header.encode('hex')
		# detect Canon cr2 headers
		if (headerhex == cr2_header):
			result = True
			self.extension = "cr2"
		
		# WAV files	
		if (headerhex[0:8] == wav_header):
			result = True
			self.extension = "wav"
			
		# JPEG files	
		if (headerhex[0:7] == jpeg_header):
			result = True
			self.extension = "jpg"			
			
			
		return result

if __name__ == "__main__":
	recover = RecoverImages(sys.argv[1])