src/mxmMidi/RawOutstreamFile.py

   1 # -*- coding: ISO-8859-1 -*-
   2
   3 # standard library imports
   4 import sys
   5 from types import StringType
   6 from struct import unpack
   7 from cStringIO import StringIO
   8
   9 # custom import
  10 from DataTypeConverters import writeBew, writeVar, fromBytes
  11
  12 class RawOutstreamFile:
  13
  14     """
  15
  16     Writes a midi file to disk.
  17
  18     """
  19
  20     def __init__(self, outfile=''):
  21         self.buffer = StringIO()
  22         self.outfile = outfile
  23
  24
  25     # native data reading functions
  26
  27
  28     def writeSlice(self, str_slice):
  29         "Writes the next text slice to the raw data"
  30         self.buffer.write(str_slice)
  31
  32
  33     def writeBew(self, value, length=1):
  34         "Writes a value to the file as big endian word"
  35         self.writeSlice(writeBew(value, length))
  36
  37
  38     def writeVarLen(self, value):
  39         "Writes a variable length word to the file"
  40         var = self.writeSlice(writeVar(value))
  41
  42
  43     def write(self):
  44         "Writes to disc"
  45         if self.outfile:
  46             if isinstance(self.outfile, StringType):
  47                 outfile = open(self.outfile, 'wb')
  48                 outfile.write(self.getvalue())
  49                 outfile.close()
  50             else:
  51                 self.outfile.write(self.getvalue())
  52         else:
  53             sys.stdout.write(self.getvalue())
  54
  55     def getvalue(self):
  56         return self.buffer.getvalue()
  57
  58
  59 if __name__ == '__main__':
  60
  61     out_file = 'test/midifiles/midiout.mid'
  62     out_file = ''
  63     rawOut = RawOutstreamFile(out_file)
  64     rawOut.writeSlice('MThd')
  65     rawOut.writeBew(6, 4)
  66     rawOut.writeBew(1, 2)
  67     rawOut.writeBew(2, 2)
  68     rawOut.writeBew(15360, 2)
  69     rawOut.write()