--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/symbian-qemu-0.9.1-12/python-2.6.1/Lib/wave.py Fri Jul 31 15:01:17 2009 +0100
@@ -0,0 +1,499 @@
+"""Stuff to parse WAVE files.
+
+Usage.
+
+Reading WAVE files:
+ f = wave.open(file, 'r')
+where file is either the name of a file or an open file pointer.
+The open file pointer must have methods read(), seek(), and close().
+When the setpos() and rewind() methods are not used, the seek()
+method is not necessary.
+
+This returns an instance of a class with the following public methods:
+ getnchannels() -- returns number of audio channels (1 for
+ mono, 2 for stereo)
+ getsampwidth() -- returns sample width in bytes
+ getframerate() -- returns sampling frequency
+ getnframes() -- returns number of audio frames
+ getcomptype() -- returns compression type ('NONE' for linear samples)
+ getcompname() -- returns human-readable version of
+ compression type ('not compressed' linear samples)
+ getparams() -- returns a tuple consisting of all of the
+ above in the above order
+ getmarkers() -- returns None (for compatibility with the
+ aifc module)
+ getmark(id) -- raises an error since the mark does not
+ exist (for compatibility with the aifc module)
+ readframes(n) -- returns at most n frames of audio
+ rewind() -- rewind to the beginning of the audio stream
+ setpos(pos) -- seek to the specified position
+ tell() -- return the current position
+ close() -- close the instance (make it unusable)
+The position returned by tell() and the position given to setpos()
+are compatible and have nothing to do with the actual position in the
+file.
+The close() method is called automatically when the class instance
+is destroyed.
+
+Writing WAVE files:
+ f = wave.open(file, 'w')
+where file is either the name of a file or an open file pointer.
+The open file pointer must have methods write(), tell(), seek(), and
+close().
+
+This returns an instance of a class with the following public methods:
+ setnchannels(n) -- set the number of channels
+ setsampwidth(n) -- set the sample width
+ setframerate(n) -- set the frame rate
+ setnframes(n) -- set the number of frames
+ setcomptype(type, name)
+ -- set the compression type and the
+ human-readable compression type
+ setparams(tuple)
+ -- set all parameters at once
+ tell() -- return current position in output file
+ writeframesraw(data)
+ -- write audio frames without pathing up the
+ file header
+ writeframes(data)
+ -- write audio frames and patch up the file header
+ close() -- patch up the file header and close the
+ output file
+You should set the parameters before the first writeframesraw or
+writeframes. The total number of frames does not need to be set,
+but when it is set to the correct value, the header does not have to
+be patched up.
+It is best to first set all parameters, perhaps possibly the
+compression type, and then write audio frames using writeframesraw.
+When all frames have been written, either call writeframes('') or
+close() to patch up the sizes in the header.
+The close() method is called automatically when the class instance
+is destroyed.
+"""
+
+import __builtin__
+
+__all__ = ["open", "openfp", "Error"]
+
+class Error(Exception):
+ pass
+
+WAVE_FORMAT_PCM = 0x0001
+
+_array_fmts = None, 'b', 'h', None, 'l'
+
+# Determine endian-ness
+import struct
+if struct.pack("h", 1) == "\000\001":
+ big_endian = 1
+else:
+ big_endian = 0
+
+from chunk import Chunk
+
+class Wave_read:
+ """Variables used in this class:
+
+ These variables are available to the user though appropriate
+ methods of this class:
+ _file -- the open file with methods read(), close(), and seek()
+ set through the __init__() method
+ _nchannels -- the number of audio channels
+ available through the getnchannels() method
+ _nframes -- the number of audio frames
+ available through the getnframes() method
+ _sampwidth -- the number of bytes per audio sample
+ available through the getsampwidth() method
+ _framerate -- the sampling frequency
+ available through the getframerate() method
+ _comptype -- the AIFF-C compression type ('NONE' if AIFF)
+ available through the getcomptype() method
+ _compname -- the human-readable AIFF-C compression type
+ available through the getcomptype() method
+ _soundpos -- the position in the audio stream
+ available through the tell() method, set through the
+ setpos() method
+
+ These variables are used internally only:
+ _fmt_chunk_read -- 1 iff the FMT chunk has been read
+ _data_seek_needed -- 1 iff positioned correctly in audio
+ file for readframes()
+ _data_chunk -- instantiation of a chunk class for the DATA chunk
+ _framesize -- size of one frame in the file
+ """
+
+ def initfp(self, file):
+ self._convert = None
+ self._soundpos = 0
+ self._file = Chunk(file, bigendian = 0)
+ if self._file.getname() != 'RIFF':
+ raise Error, 'file does not start with RIFF id'
+ if self._file.read(4) != 'WAVE':
+ raise Error, 'not a WAVE file'
+ self._fmt_chunk_read = 0
+ self._data_chunk = None
+ while 1:
+ self._data_seek_needed = 1
+ try:
+ chunk = Chunk(self._file, bigendian = 0)
+ except EOFError:
+ break
+ chunkname = chunk.getname()
+ if chunkname == 'fmt ':
+ self._read_fmt_chunk(chunk)
+ self._fmt_chunk_read = 1
+ elif chunkname == 'data':
+ if not self._fmt_chunk_read:
+ raise Error, 'data chunk before fmt chunk'
+ self._data_chunk = chunk
+ self._nframes = chunk.chunksize // self._framesize
+ self._data_seek_needed = 0
+ break
+ chunk.skip()
+ if not self._fmt_chunk_read or not self._data_chunk:
+ raise Error, 'fmt chunk and/or data chunk missing'
+
+ def __init__(self, f):
+ self._i_opened_the_file = None
+ if isinstance(f, basestring):
+ f = __builtin__.open(f, 'rb')
+ self._i_opened_the_file = f
+ # else, assume it is an open file object already
+ try:
+ self.initfp(f)
+ except:
+ if self._i_opened_the_file:
+ f.close()
+ raise
+
+ def __del__(self):
+ self.close()
+ #
+ # User visible methods.
+ #
+ def getfp(self):
+ return self._file
+
+ def rewind(self):
+ self._data_seek_needed = 1
+ self._soundpos = 0
+
+ def close(self):
+ if self._i_opened_the_file:
+ self._i_opened_the_file.close()
+ self._i_opened_the_file = None
+ self._file = None
+
+ def tell(self):
+ return self._soundpos
+
+ def getnchannels(self):
+ return self._nchannels
+
+ def getnframes(self):
+ return self._nframes
+
+ def getsampwidth(self):
+ return self._sampwidth
+
+ def getframerate(self):
+ return self._framerate
+
+ def getcomptype(self):
+ return self._comptype
+
+ def getcompname(self):
+ return self._compname
+
+ def getparams(self):
+ return self.getnchannels(), self.getsampwidth(), \
+ self.getframerate(), self.getnframes(), \
+ self.getcomptype(), self.getcompname()
+
+ def getmarkers(self):
+ return None
+
+ def getmark(self, id):
+ raise Error, 'no marks'
+
+ def setpos(self, pos):
+ if pos < 0 or pos > self._nframes:
+ raise Error, 'position not in range'
+ self._soundpos = pos
+ self._data_seek_needed = 1
+
+ def readframes(self, nframes):
+ if self._data_seek_needed:
+ self._data_chunk.seek(0, 0)
+ pos = self._soundpos * self._framesize
+ if pos:
+ self._data_chunk.seek(pos, 0)
+ self._data_seek_needed = 0
+ if nframes == 0:
+ return ''
+ if self._sampwidth > 1 and big_endian:
+ # unfortunately the fromfile() method does not take
+ # something that only looks like a file object, so
+ # we have to reach into the innards of the chunk object
+ import array
+ chunk = self._data_chunk
+ data = array.array(_array_fmts[self._sampwidth])
+ nitems = nframes * self._nchannels
+ if nitems * self._sampwidth > chunk.chunksize - chunk.size_read:
+ nitems = (chunk.chunksize - chunk.size_read) / self._sampwidth
+ data.fromfile(chunk.file.file, nitems)
+ # "tell" data chunk how much was read
+ chunk.size_read = chunk.size_read + nitems * self._sampwidth
+ # do the same for the outermost chunk
+ chunk = chunk.file
+ chunk.size_read = chunk.size_read + nitems * self._sampwidth
+ data.byteswap()
+ data = data.tostring()
+ else:
+ data = self._data_chunk.read(nframes * self._framesize)
+ if self._convert and data:
+ data = self._convert(data)
+ self._soundpos = self._soundpos + len(data) // (self._nchannels * self._sampwidth)
+ return data
+
+ #
+ # Internal methods.
+ #
+
+ def _read_fmt_chunk(self, chunk):
+ wFormatTag, self._nchannels, self._framerate, dwAvgBytesPerSec, wBlockAlign = struct.unpack('<hhllh', chunk.read(14))
+ if wFormatTag == WAVE_FORMAT_PCM:
+ sampwidth = struct.unpack('<h', chunk.read(2))[0]
+ self._sampwidth = (sampwidth + 7) // 8
+ else:
+ raise Error, 'unknown format: %r' % (wFormatTag,)
+ self._framesize = self._nchannels * self._sampwidth
+ self._comptype = 'NONE'
+ self._compname = 'not compressed'
+
+class Wave_write:
+ """Variables used in this class:
+
+ These variables are user settable through appropriate methods
+ of this class:
+ _file -- the open file with methods write(), close(), tell(), seek()
+ set through the __init__() method
+ _comptype -- the AIFF-C compression type ('NONE' in AIFF)
+ set through the setcomptype() or setparams() method
+ _compname -- the human-readable AIFF-C compression type
+ set through the setcomptype() or setparams() method
+ _nchannels -- the number of audio channels
+ set through the setnchannels() or setparams() method
+ _sampwidth -- the number of bytes per audio sample
+ set through the setsampwidth() or setparams() method
+ _framerate -- the sampling frequency
+ set through the setframerate() or setparams() method
+ _nframes -- the number of audio frames written to the header
+ set through the setnframes() or setparams() method
+
+ These variables are used internally only:
+ _datalength -- the size of the audio samples written to the header
+ _nframeswritten -- the number of frames actually written
+ _datawritten -- the size of the audio samples actually written
+ """
+
+ def __init__(self, f):
+ self._i_opened_the_file = None
+ if isinstance(f, basestring):
+ f = __builtin__.open(f, 'wb')
+ self._i_opened_the_file = f
+ try:
+ self.initfp(f)
+ except:
+ if self._i_opened_the_file:
+ f.close()
+ raise
+
+ def initfp(self, file):
+ self._file = file
+ self._convert = None
+ self._nchannels = 0
+ self._sampwidth = 0
+ self._framerate = 0
+ self._nframes = 0
+ self._nframeswritten = 0
+ self._datawritten = 0
+ self._datalength = 0
+
+ def __del__(self):
+ self.close()
+
+ #
+ # User visible methods.
+ #
+ def setnchannels(self, nchannels):
+ if self._datawritten:
+ raise Error, 'cannot change parameters after starting to write'
+ if nchannels < 1:
+ raise Error, 'bad # of channels'
+ self._nchannels = nchannels
+
+ def getnchannels(self):
+ if not self._nchannels:
+ raise Error, 'number of channels not set'
+ return self._nchannels
+
+ def setsampwidth(self, sampwidth):
+ if self._datawritten:
+ raise Error, 'cannot change parameters after starting to write'
+ if sampwidth < 1 or sampwidth > 4:
+ raise Error, 'bad sample width'
+ self._sampwidth = sampwidth
+
+ def getsampwidth(self):
+ if not self._sampwidth:
+ raise Error, 'sample width not set'
+ return self._sampwidth
+
+ def setframerate(self, framerate):
+ if self._datawritten:
+ raise Error, 'cannot change parameters after starting to write'
+ if framerate <= 0:
+ raise Error, 'bad frame rate'
+ self._framerate = framerate
+
+ def getframerate(self):
+ if not self._framerate:
+ raise Error, 'frame rate not set'
+ return self._framerate
+
+ def setnframes(self, nframes):
+ if self._datawritten:
+ raise Error, 'cannot change parameters after starting to write'
+ self._nframes = nframes
+
+ def getnframes(self):
+ return self._nframeswritten
+
+ def setcomptype(self, comptype, compname):
+ if self._datawritten:
+ raise Error, 'cannot change parameters after starting to write'
+ if comptype not in ('NONE',):
+ raise Error, 'unsupported compression type'
+ self._comptype = comptype
+ self._compname = compname
+
+ def getcomptype(self):
+ return self._comptype
+
+ def getcompname(self):
+ return self._compname
+
+ def setparams(self, (nchannels, sampwidth, framerate, nframes, comptype, compname)):
+ if self._datawritten:
+ raise Error, 'cannot change parameters after starting to write'
+ self.setnchannels(nchannels)
+ self.setsampwidth(sampwidth)
+ self.setframerate(framerate)
+ self.setnframes(nframes)
+ self.setcomptype(comptype, compname)
+
+ def getparams(self):
+ if not self._nchannels or not self._sampwidth or not self._framerate:
+ raise Error, 'not all parameters set'
+ return self._nchannels, self._sampwidth, self._framerate, \
+ self._nframes, self._comptype, self._compname
+
+ def setmark(self, id, pos, name):
+ raise Error, 'setmark() not supported'
+
+ def getmark(self, id):
+ raise Error, 'no marks'
+
+ def getmarkers(self):
+ return None
+
+ def tell(self):
+ return self._nframeswritten
+
+ def writeframesraw(self, data):
+ self._ensure_header_written(len(data))
+ nframes = len(data) // (self._sampwidth * self._nchannels)
+ if self._convert:
+ data = self._convert(data)
+ if self._sampwidth > 1 and big_endian:
+ import array
+ data = array.array(_array_fmts[self._sampwidth], data)
+ data.byteswap()
+ data.tofile(self._file)
+ self._datawritten = self._datawritten + len(data) * self._sampwidth
+ else:
+ self._file.write(data)
+ self._datawritten = self._datawritten + len(data)
+ self._nframeswritten = self._nframeswritten + nframes
+
+ def writeframes(self, data):
+ self.writeframesraw(data)
+ if self._datalength != self._datawritten:
+ self._patchheader()
+
+ def close(self):
+ if self._file:
+ self._ensure_header_written(0)
+ if self._datalength != self._datawritten:
+ self._patchheader()
+ self._file.flush()
+ self._file = None
+ if self._i_opened_the_file:
+ self._i_opened_the_file.close()
+ self._i_opened_the_file = None
+
+ #
+ # Internal methods.
+ #
+
+ def _ensure_header_written(self, datasize):
+ if not self._datawritten:
+ if not self._nchannels:
+ raise Error, '# channels not specified'
+ if not self._sampwidth:
+ raise Error, 'sample width not specified'
+ if not self._framerate:
+ raise Error, 'sampling rate not specified'
+ self._write_header(datasize)
+
+ def _write_header(self, initlength):
+ self._file.write('RIFF')
+ if not self._nframes:
+ self._nframes = initlength / (self._nchannels * self._sampwidth)
+ self._datalength = self._nframes * self._nchannels * self._sampwidth
+ self._form_length_pos = self._file.tell()
+ self._file.write(struct.pack('<l4s4slhhllhh4s',
+ 36 + self._datalength, 'WAVE', 'fmt ', 16,
+ WAVE_FORMAT_PCM, self._nchannels, self._framerate,
+ self._nchannels * self._framerate * self._sampwidth,
+ self._nchannels * self._sampwidth,
+ self._sampwidth * 8, 'data'))
+ self._data_length_pos = self._file.tell()
+ self._file.write(struct.pack('<l', self._datalength))
+
+ def _patchheader(self):
+ if self._datawritten == self._datalength:
+ return
+ curpos = self._file.tell()
+ self._file.seek(self._form_length_pos, 0)
+ self._file.write(struct.pack('<l', 36 + self._datawritten))
+ self._file.seek(self._data_length_pos, 0)
+ self._file.write(struct.pack('<l', self._datawritten))
+ self._file.seek(curpos, 0)
+ self._datalength = self._datawritten
+
+def open(f, mode=None):
+ if mode is None:
+ if hasattr(f, 'mode'):
+ mode = f.mode
+ else:
+ mode = 'rb'
+ if mode in ('r', 'rb'):
+ return Wave_read(f)
+ elif mode in ('w', 'wb'):
+ return Wave_write(f)
+ else:
+ raise Error, "mode must be 'r', 'rb', 'w', or 'wb'"
+
+openfp = open # B/W compatibility