mirror of
https://github.com/python/cpython.git
synced 2024-11-25 02:44:06 +08:00
54e54c6877
mostly changes of / operators into //. Once or twice I did more or less than recommended.
490 lines
17 KiB
Python
490 lines
17 KiB
Python
"""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 type(f) == type(''):
|
|
f = __builtin__.open(f, 'rb')
|
|
self._i_opened_the_file = f
|
|
# else, assume it is an open file object already
|
|
self.initfp(f)
|
|
|
|
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: ' + `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 type(f) == type(''):
|
|
f = __builtin__.open(f, 'wb')
|
|
self._i_opened_the_file = f
|
|
self.initfp(f)
|
|
|
|
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
|