e@0: # -*- coding: utf-8 -*-
e@0: """
e@0: Spectral Constrast as described in Dan-Ning Jiang et al (2002)
e@0: 
e@0: Created on Tue Apr 14 17:31:20 2015
e@0: 
e@0: @author: Emmanouil Theofanis Chourdakis
e@0: 
e@0: 
e@0: """
e@0: 
e@0: import essentia
e@0: from essentia.streaming import *
e@0: from essentia.standard import YamlOutput
e@0: from sys import argv
e@0: from pylab import *
e@0: from numpy import *
e@0: 
e@0: 
e@0: 
e@0: 
e@0: if __name__=="__main__":
e@0:     if len(argv) < 2:
e@0:         print("Please provide an input filename.")
e@0:     else:
e@0:         fname = argv[1]
e@0:         print("Onset Demo with `%s\'" % fname)
e@0:         
e@0:         SR = 16000.0 # Sampling Rate
e@0:         T = 1./SR # Sampling Period
e@0:         FS = 23.0 # ms
e@0:         
e@0:         # Describing the building blocks
e@0:         
e@0:         loader = MonoLoader(filename = fname, sampleRate = SR)
e@0:         
e@0:         onset = OnsetRate()
e@0:         
e@0:         # Pool (for output purposes)
e@0: 
e@0:         pool = essentia.Pool()          
e@0:         
e@0:         
e@0:         # Describing the connections
e@0:         
e@0:         
e@0:         loader.audio  >> onset.signal
e@0:         loader.audio >> (pool, 'audio')
e@0:         onset.onsetRate >> None
e@0:         onset.onsetTimes >> (pool, 'onsettimes')
e@0:         
e@0:         
e@0:         # Run it
e@0:         
e@0:         essentia.run(loader)
e@0:         
e@0:         
e@0:         # Save the pool as a yaml file.
e@0:         output = YamlOutput(filename = "%s.yaml" % fname.partition('/')[2].partition('.')[0])(pool)
e@0:         
e@0: 
e@0:         ons = zeros((len(pool['audio']),1))
e@0:         
e@0:         for i in range(0,len(pool['onsettimes'])):
e@0:             ons[pool['onsettimes'][i]*44100]= 1
e@0:             
e@0:             
e@0:         t = linspace(0, len(pool['audio'])*T, len(pool['audio']))           
e@0:         
e@0:         plot(t, pool['audio'], t, ons);
e@0:         xlabel('time (s)')
e@0:         ylabel('f(t)')
e@0:         title('Onset Detection Function')
e@0:         savefig('output.png',  dpi=600)
e@0:         
e@0: 
e@0:         show()
e@0:         
e@0:         
e@0:     
e@0: 
e@0: