Revision 6:fd0f9d0615b2 9-dsp-block-by-block.py

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9-dsp-block-by-block.py
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import numpy as np
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import pylab as plt
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from scikits.audiolab import wavread
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#################################################


  		




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#################################################


  		




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#### CALCULATE RMS OF EACH AUDIO BLOCK ####


  		




  
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####### CALCULATE RMS OF EACH AUDIO BLOCK #######


  		




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#################################################


  		




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hop_size = 2048                             # set hop size


  		




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frame_size = 4096                           # set frame size


  		




  
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hop_size = 512                             # set hop size


  		




  
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frame_size = hop_size*2                     # set frame size


  		




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frame = np.zeros(frame_size)                # initialise frame with zeros


  		




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window = np.hanning(frame_size)             # create window of the same length as the hop size


  		




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for n in range(0,x.size-hop_size,hop_size):


  		




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    # extract a segment of length hop_size


  		




  
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    frame = x[n:n+hop_size]                               


  		




  
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    # calculate RMS


  		




  
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    rms_val = np.sqrt(np.power(frame,2).mean())


  		




  
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    # add amplitude to our numpy array


  		




  
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    rms = np.append(rms,rms_val)


  		




  
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print rms


  		




  
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""" I AM THE OVERLAP VERSION


  		




  
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# run through signal frame by frame 


  		




  
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for n in range(0,x.size-hop_size,hop_size):


  		




  
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    # extract a segment of length hop_size


  		




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    buffer = x[n:n+hop_size]                               


  		




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    # add new segment to frame, shifting back samples of frame


  		




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    rms = np.append(rms,rms_val)


  		




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print rms


  		




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"""


  		




  
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plt.plot(rms)


  		




  
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plt.title("RMS")


  		




  
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plt.xlabel("time")


  		




  
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plt.ylabel("value")


  		




  
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plt.show()


  		




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