Source Code for Module timeside.analyzer.spectrogram

 1  # -*- coding: utf-8 -*- 
 2  # 
 3  # Copyright (c) 2013 Paul Brossier <piem@piem.org> 
 4   
 5  # This file is part of TimeSide. 
 6   
 7  # TimeSide is free software: you can redistribute it and/or modify 
 8  # it under the terms of the GNU General Public License as published by 
 9  # the Free Software Foundation, either version 2 of the License, or 
10  # (at your option) any later version. 
11   
12  # TimeSide is distributed in the hope that it will be useful, 
13  # but WITHOUT ANY WARRANTY; without even the implied warranty of 
14  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
15  # GNU General Public License for more details. 
16   
17  # You should have received a copy of the GNU General Public License 
18  # along with TimeSide.  If not, see <http://www.gnu.org/licenses/>. 
19   
20  # Author: Paul Brossier <piem@piem.org> 
21   
22  from timeside.core import implements, interfacedoc 
23  from timeside.analyzer.core import Analyzer 
24  from timeside.api import IAnalyzer 
25  from preprocessors import downmix_to_mono, frames_adapter 
26  import numpy as np 
27   
28   
29 -class Spectrogram(Analyzer): 
30      implements(IAnalyzer) 
31   
32 -    def __init__(self, blocksize=2048, stepsize=None): 
33          super(Spectrogram, self).__init__() 
34   
35          self.input_blocksize = blocksize 
36          if stepsize: 
37              self.input_stepsize = stepsize 
38          else: 
39              self.input_stepsize = blocksize / 2 
40   
41      @interfacedoc 
42 -    def setup(self, channels=None, samplerate=None, 
43                blocksize=None, totalframes=None): 
44          super(Spectrogram, self).setup(channels, samplerate, 
45                blocksize, totalframes) 
46   
47          self.values = [] 
48          self.FFT_SIZE = 2048 
49   
50      @staticmethod 
51      @interfacedoc 
52 -    def id(): 
53          return "spectrogram_analyzer" 
54   
55      @staticmethod 
56      @interfacedoc 
57 -    def name(): 
58          return "Spectrogram Analyzer" 
59   
60      @staticmethod 
61      @interfacedoc 
62 -    def unit(): 
63          return "" 
64   
65      @downmix_to_mono 
66      @frames_adapter 
67 -    def process(self, frames, eod=False): 
68              self.values.append(np.abs(np.fft.rfft(frames, self.FFT_SIZE))) 
69              return frames, eod 
70   
71 -    def post_process(self): 
72          spectrogram = self.new_result(data_mode='value', time_mode='framewise') 
73          spectrogram.parameters = {'FFT_SIZE': self.FFT_SIZE} 
74          spectrogram.data_object.value = self.values 
75          self.process_pipe.results.add(spectrogram) 
76