Source Code for Module jazzparser.harmonical.files

 1  """File I/O classes for the harmonical 
 2   
 3  """ 
 4  """ 
 5  ============================== License ======================================== 
 6   Copyright (C) 2008, 2010-12 University of Edinburgh, Mark Granroth-Wilding 
 7    
 8   This file is part of The Jazz Parser. 
 9    
10   The Jazz Parser is free software: you can redistribute it and/or modify 
11   it under the terms of the GNU General Public License as published by 
12   the Free Software Foundation, either version 3 of the License, or 
13   (at your option) any later version. 
14    
15   The Jazz Parser is distributed in the hope that it will be useful, 
16   but WITHOUT ANY WARRANTY; without even the implied warranty of 
17   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
18   GNU General Public License for more details. 
19    
20   You should have received a copy of the GNU General Public License 
21   along with The Jazz Parser.  If not, see <http://www.gnu.org/licenses/>. 
22   
23  ============================ End license ====================================== 
24   
25  """ 
26  __author__ = "Mark Granroth-Wilding <mark.granroth-wilding@ed.ac.uk>"  
27   
28  import wave, os.path 
29   
30  DEFAULT_SAMPLE_RATE = 44100 
31   
32 -class SoundFile(object): 
33      """ 
34      A wave file to store uncompressed audio signal data. 
35      """ 
36 -    def  __init__(self, filename="audio.wav", sample_rate=DEFAULT_SAMPLE_RATE): 
37          self.filename = filename 
38          self._signal = [] 
39          self.sr = sample_rate 
40   
41 -    def save(self): 
42          file = wave.open(self.filename, 'wb') 
43          # Convert the numerical data into a binary string 
44          str_signal = self.get_data() 
45   
46          file.setparams((1, 2, self.sr, self.sr*4, 'NONE', 'noncompressed')) 
47          file.writeframes(str_signal) 
48          file.close() 
49       
50 -    def set_signal(self, signal): 
51          self._signal = signal 
52           
53 -    def add_signal(self, signal): 
54          self._signal.extend(signal) 
55           
56 -    def add_silence(self, seconds=1.0): 
57          self.add_signal([0]*int(self.sr*seconds)) 
58           
59 -    def get_data(self): 
60          """ 
61          Return the raw data that will be written to the file. 
62           
63          """ 
64          return ''.join([wave.struct.pack('h', samp) for samp in self._signal]) 
65           
66 -    def get_buffer(self): 
67          """ 
68          Returns a file-like object containing the data that would be  
69          written to the file. This object won't get updated if the  
70          SoundFile is changed. 
71           
72          """ 
73          from StringIO import StringIO 
74          return StringIO(self.get_data()) 
75   
76 -def save_wave_data(signal, filename): 
77      """ 
78      Shortcut to store a wave file given some sample data. 
79      Assumes the standard sample rate. 
80       
81      """ 
82      filename = os.path.abspath(filename) 
83      f = SoundFile(filename) 
84      f.set_signal(signal) 
85      f.save() 
86