plugins/_wav.py

   1 """
   2
   3         Copyright 2005 Kenneth Hayber <ken@hayber.us>, All rights reserved.
   4
   5         This program is free software; you can redistribute it and/or modify
   6         it under the terms of the GNU General Public License as published by
   7         the Free Software Foundation; either version 2 of the License.
   8
   9         This program is distributed in the hope that it will be useful
  10         but WITHOUT ANY WARRANTY; without even the implied warranty of
  11         MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12         GNU General Public License for more details.
  13
  14         You should have received a copy of the GNU General Public License
  15         along with this program; if not, write to the Free Software
  16         Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  17 """
  18
  19 try:
  20         import wave
  21         HAVE_WAV = True
  22 except:
  23         HAVE_WAV = False
  24         print 'No WAV support'
  25
  26
  27 def get_info(song):
  28         #TODO or NOP?
  29         pass
  30
  31
  32 class WAVDecoder:
  33         """
  34         A decoder to process WAV sound files.  Utilizes the standard python wave module
  35         Called from the Player class to read and decode WAV files.
  36         """
  37         def __init__(self, filename, buffersize):
  38                 """Initialize the decoder"""
  39                 self.buffersize = buffersize
  40                 self.filename = filename
  41
  42         def open(self):
  43                 """Open the file and prepare for decoding"""
  44                 self.wv = wave.open(self.filename, 'r')
  45
  46         def close(self):
  47                 """Close the file and do any needed cleanup"""
  48                 pass
  49
  50         def length(self):
  51                 """Return the length of the file in seconds as an integer"""
  52                 return self.wv.getnframes() / self.wv.getframerate()
  53
  54         def samplerate(self):
  55                 """Return the sample rate of the file in samples per second"""
  56                 return self.wv.getframerate()
  57
  58         def channels(self):
  59                 """Return the number of channels in the file"""
  60                 return self.wv.getnchannels()
  61
  62         def read(self):
  63                 """
  64                 Read data from the file and decode to PCM data. Return a buffer
  65                 of data and length, or (None, 0) at EOF
  66                 """
  67                 buff = self.wv.readframes(self.buffersize)
  68                 bytes = len(buff)
  69                 if not bytes:
  70                         buff = None
  71                 return (buff, bytes)
  72
  73         def tell(self):
  74                 """Return the current playback position in seconds"""
  75                 return self.wv.tell() / self.wv.getframerate()
  76
  77         def seek(self, pos):
  78                 """Jump to pos as a percentage of the total length of the file"""
  79                 self.wv.setpos(int(pos * self.wv.getnframes()))
  80
  81         def info(self):
  82                 """Print some info about this WAV file"""
  83                 print "no info for WAV files"
  84