fazekasgy@37: '''PyZeroCrossing.py - Example plugin demonstrates
fazekasgy@37: how to write a Vampy plugin in pure Python without
fazekasgy@37: using Numpy or the extensions provided by the embedded 
fazekasgy@37: vampy module. 
fazekasgy@37: 
fazekasgy@37: This plugin is compatible with provious versions of vampy, 
fazekasgy@37: apart from moving the inputSampleRate
fazekasgy@37: argument from initialise to __init__()
fazekasgy@37: 
fazekasgy@37: Outputs: 
fazekasgy@37: 1) Zero crossing counts
fazekasgy@37: 2) Zero crossing locations
fazekasgy@37: 
fazekasgy@37: Centre for Digital Music, Queen Mary University of London.
fazekasgy@37: Copyright (C) 2009 Gyorgy Fazekas, QMUL. (See Vamp sources 
fazekasgy@37: for licence information.)
fazekasgy@37: 
fazekasgy@37: '''
fazekasgy@37: 
fazekasgy@37: class PyZeroCrossing: 
fazekasgy@37: 	
fazekasgy@37: 	def __init__(self,inputSampleRate): 
fazekasgy@37: 		self.m_inputSampleRate = inputSampleRate 
fazekasgy@37: 		self.m_stepSize = 0
fazekasgy@37: 		self.m_blockSize = 0
fazekasgy@37: 		self.m_channels = 0
fazekasgy@37: 		self.previousSample = 0.0
fazekasgy@37: 		self.threshold = 0.005
fazekasgy@37: 		self.counter = 0
fazekasgy@37: 		
fazekasgy@37: 	def initialise(self,channels,stepSize,blockSize):
fazekasgy@37: 		self.m_channels = channels
fazekasgy@37: 		self.m_stepSize = stepSize		
fazekasgy@37: 		self.m_blockSize = blockSize
fazekasgy@37: 		return True
fazekasgy@37: 	
fazekasgy@37: 	def getMaker(self):
fazekasgy@37: 		return 'Vampy Example Plugins'
fazekasgy@37: 	
fazekasgy@37: 	def getName(self):
fazekasgy@37: 		return 'Vampy Zero Crossings'
Chris@69: 
Chris@69:         def getDescription(self):
Chris@69:                 return 'Count the number of simple zero-crossings for the signal within each processing block'
Chris@69: 
Chris@69:         def getCopyright(self):
Chris@69:                 return 'Plugin By George Fazekas. Freely redistributable example plugin (BSD license)'
fazekasgy@37: 		
fazekasgy@37: 	def getIdentifier(self):
fazekasgy@37: 		return 'vampy-zc2'
fazekasgy@37: 	
fazekasgy@37: 	def getMaxChannelCount(self):
fazekasgy@37: 		return 1
fazekasgy@37: 		
fazekasgy@37: 	def getInputDomain(self):
fazekasgy@37: 		return 'TimeDomain'
fazekasgy@37: 			
fazekasgy@37: 	def getOutputDescriptors(self):
fazekasgy@37: 		
fazekasgy@37: 		#descriptors can be returned as python dictionaries
fazekasgy@37: 		output0={
fazekasgy@37: 		'identifier':'vampy-counts',
fazekasgy@37: 		'name':'Number of Zero Crossings',
fazekasgy@37: 		'description':'Number of zero crossings per audio frame',
fazekasgy@37: 		'unit':' ',
fazekasgy@37: 		'hasFixedBinCount':True,
fazekasgy@37: 		'binCount':1,
fazekasgy@37: 		#'binNames':['1 Hz',1.5,'2 Hz',3,'4 Hz'],
fazekasgy@37: 		'hasKnownExtents':False,
fazekasgy@37: 		#'minValue':0.0,
fazekasgy@37: 		#'maxValue':0.0,
fazekasgy@37: 		'isQuantized':True,
fazekasgy@37: 		'quantizeStep':1.0,
fazekasgy@37: 		'sampleType':'OneSamplePerStep'
fazekasgy@37: 		#'sampleRate':48000.0
fazekasgy@37: 		}
fazekasgy@37: 
fazekasgy@37: 		output1={
fazekasgy@37: 		'identifier':'vampy-crossings',
fazekasgy@37: 		'name':'Zero Crossing Locations',
fazekasgy@37: 		'description':'The locations of zero crossing points',
fazekasgy@37: 		'unit':'discrete',
fazekasgy@37: 		'hasFixedBinCount':True,
fazekasgy@37: 		'binCount':0,
fazekasgy@37: 		'sampleType':'VariableSampleRate'
fazekasgy@37: 		}
fazekasgy@37: 
fazekasgy@37: 		return [output0,output1]
fazekasgy@37: 
fazekasgy@37: 
fazekasgy@37: 	def getParameterDescriptors(self):
fazekasgy@37: 		paramlist1={
fazekasgy@37: 		'identifier':'threshold',
fazekasgy@37: 		'name':'Noise threshold',
Chris@68: 		'description':'Magnitude below which a process block will be considered to be all zero',
fazekasgy@37: 		'unit':'v',
fazekasgy@37: 		'minValue':0.0,
fazekasgy@37: 		'maxValue':0.5,
fazekasgy@37: 		'defaultValue':0.005,
fazekasgy@37: 		'isQuantized':False
fazekasgy@37: 		}
fazekasgy@37: 		return [paramlist1]
fazekasgy@37: 
fazekasgy@37: 
fazekasgy@37: 	def setParameter(self,paramid,newval):
fazekasgy@37: 		if paramid == 'threshold' :
fazekasgy@37: 			self.threshold = newval
fazekasgy@37: 		return
fazekasgy@37: 
fazekasgy@37: 		
fazekasgy@37: 	def getParameter(self,paramid):
fazekasgy@37: 		if paramid == 'threshold' :
fazekasgy@37: 			return self.threshold
fazekasgy@37: 		else:
fazekasgy@37: 			return 0.0
fazekasgy@37: 
fazekasgy@37: 
fazekasgy@37: 	# legacy process type: the input is a python list of samples
fazekasgy@37: 	def process(self,inbuf,timestamp):
fazekasgy@37: 		crossing = False
fazekasgy@37: 		prev = self.previousSample
fazekasgy@37: 		count = 0.0;
fazekasgy@37: 		channel = inbuf[0]
fazekasgy@37: 
fazekasgy@37: 		#we have two outputs defined thus we have to declare
fazekasgy@37: 		#them as empty dictionaries in our output list
fazekasgy@37: 		#in order to be able to return variable rate outputs
fazekasgy@37: 		output0=[]
fazekasgy@37: 		output1=[]
fazekasgy@37: 
fazekasgy@37: 		if sum([abs(s) for s in channel]) > self.threshold : 
fazekasgy@37: 
fazekasgy@37: 			for x in range(len(channel)-1) :
fazekasgy@37: 				crossing = False
fazekasgy@37: 				sample = channel[x]
fazekasgy@37: 				if sample <= 0.0 : 
fazekasgy@37: 					if prev > 0.0 : crossing = True
fazekasgy@37: 				else :
fazekasgy@37: 					if sample > 0.0 :
fazekasgy@37: 						if prev <= 0.0 : crossing = True		
fazekasgy@37: 			
fazekasgy@37: 				if crossing == True : 
fazekasgy@37: 					count = count + 1
fazekasgy@37: 					feature1={
fazekasgy@37: 					'hasTimestamp':True,	
fazekasgy@37: 					'timeStamp':long(timestamp + x),				
fazekasgy@37: 					'values':[count],			
fazekasgy@37: 					'label':str(count),				
fazekasgy@37: 					}				
fazekasgy@37: 					output1.append(feature1)
fazekasgy@37: 			
fazekasgy@37: 				prev = sample	
fazekasgy@37: 			self.previousSample = prev
fazekasgy@37: 
fazekasgy@37: 		else :
fazekasgy@37: 			count = 0.0
fazekasgy@37: 			self.previousSample = channel[len(channel)-1]
fazekasgy@37: 
fazekasgy@37: 		feature0={
fazekasgy@37: 		'hasTimestamp':False,		
fazekasgy@37: 		'values':[count],
fazekasgy@37: 		'label':str(count)				
fazekasgy@37: 		}
fazekasgy@37: 		output0.append(feature0)
fazekasgy@37: 		
fazekasgy@37: 		#return a LIST of list of dictionaries
fazekasgy@37: 		return [output0,output1]
fazekasgy@37: