comparison Syncopation models/synpy/rhythm_parser.py @ 45:6e9154fc58df

moving the code files to the synpy package directory

+'''
+Authors: Chunyang Song, Christopher Harte
+Institution: Centre for Digital Music, Queen Mary University of London
+'''
+
+# Parse the rhythm file and return a list of Bar objects
+#Piece = []
+
+from parameter_setter import timeSignatureBase
+from music_objects import *
+
+comment_sign = '#'
+
+def discard_comments(line):
+	if comment_sign in line:
+		line = line[0:line.find(comment_sign)]
+	return line
+
+def discard_spaces(line):
+	line = line.replace(" ", '').replace("\t", '')
+	return line
+
+def discard_linereturns(line):
+	line = line.replace("\n","").replace("\r","")
+	return line
+	
+
+# def extractInfo(line):
+# 	try:
+# 		if '{' not in line and '}' not in line:
+# 			raise RhythmSyntaxError(line)
+# 		else:
+# 			return line[line.find('{')+1 : line.find('}')]
+# 	except RhythmSyntaxError:
+# 		print 'Rhythmic information needs to be enclosed by "{" and "}"'
+
+
+def read_rhythm(fileName):
+	fileContent = file(fileName)
+
+	barList = BarList()
+
+	tempo=None
+	timeSignature=None
+	ticksPerQuarter=None
+
+	# for each line in the file, parse the line and add any 
+	# new bars to the main bar list for the piece
+	for line in fileContent:
+		
+		# ignore the line if it's only a comment
+		if is_comment(line) or line=="\n":
+			continue
+
+		# if time signature has not yet been set then it should be the first 
+		# thing we find in a file after the comments at the top
+		if timeSignature==None:
+			(field, line) = get_next_field(line)
+			# if there is a valid field, it should be a time signature
+			if field!=None:
+				[fieldname,value] = field
+				if fieldname.lower()=="t":
+					timeSignature = TimeSignature(value)
+				else:
+					print 'Error, first field in the file should set the time signature.'
+
+		# parse the line
+		(newbarlist, tempo, timeSignature, ticksPerQuarter) = parse_line(line, timeSignature,  tempo, ticksPerQuarter)
+		
+		# if we found some bars in this line then add them to the overall bar list
+		if len(newbarlist)>0:
+			barList.concat(newbarlist)
+
+	return barList
+
+def is_comment(line):
+	if discard_spaces(line)[0]==comment_sign:
+		return True
+	else:
+		return False
+
+def parse_line(line,  timeSignature=None, tempo=None, ticksPerQuarter=None):
+	
+	#strip the line of line returns, spaces and comments
+	line = discard_linereturns(discard_spaces(discard_comments(line)))
+	
+	bars = BarList()
+
+	#work through each field in the line
+	while len(line)>0:
+		(field, line) = get_next_field(line)
+
+		if field!=None:
+			
+			[fieldname, value] = field
+			
+			if fieldname.lower() == "v":
+				#velocity sequence
+				bar = Bar(VelocitySequence(value),timeSignature, ticksPerQuarter, tempo)	
+				bars.append(bar)
+
+			elif fieldname.lower() == "y":
+				#note sequence	
+				bar = Bar(NoteSequence(value), timeSignature, ticksPerQuarter, tempo)	
+				bars.append(bar)
+
+			elif fieldname.lower() == "t":
+				#time signature
+				timeSignature = TimeSignature(value)
+			
+			elif fieldname.lower() == "tpq":
+				#ticks per quarter
+				ticksPerQuarter = int(value)
+			
+			elif fieldname.lower() == "qpm":
+				#tempo
+				tempo = int(value)
+			
+			else:
+				print 'Unrecognised field type: "' + fieldname + '"'
+	
+	return bars, tempo, timeSignature, ticksPerQuarter
+
+class RhythmSyntaxError(Exception):
+	def __init__(self, value):
+		self.value = value
+	def __str__(self):
+		return repr(self.value)
+
+def get_next_field(line):
+	index = line.find("}")
+	field = None
+	if index>=0:
+		fieldtext = line[:index]
+		line = line[index+1:]
+		field = fieldtext.split("{")
+	else:
+		print 'Error, incorrect syntax: "'+line+'"'
+		raise RhythmSyntaxError(line)
+
+	return field,line
+
+
+
+
+