--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/symbian-qemu-0.9.1-12/python-win32-2.6.1/lib/aifc.py Fri Jul 31 15:01:17 2009 +0100
@@ -0,0 +1,962 @@
+"""Stuff to parse AIFF-C and AIFF files.
+
+Unless explicitly stated otherwise, the description below is true
+both for AIFF-C files and AIFF files.
+
+An AIFF-C file has the following structure.
+
+ +-----------------+
+ | FORM |
+ +-----------------+
+ | <size> |
+ +----+------------+
+ | | AIFC |
+ | +------------+
+ | | <chunks> |
+ | | . |
+ | | . |
+ | | . |
+ +----+------------+
+
+An AIFF file has the string "AIFF" instead of "AIFC".
+
+A chunk consists of an identifier (4 bytes) followed by a size (4 bytes,
+big endian order), followed by the data. The size field does not include
+the size of the 8 byte header.
+
+The following chunk types are recognized.
+
+ FVER
+ <version number of AIFF-C defining document> (AIFF-C only).
+ MARK
+ <# of markers> (2 bytes)
+ list of markers:
+ <marker ID> (2 bytes, must be > 0)
+ <position> (4 bytes)
+ <marker name> ("pstring")
+ COMM
+ <# of channels> (2 bytes)
+ <# of sound frames> (4 bytes)
+ <size of the samples> (2 bytes)
+ <sampling frequency> (10 bytes, IEEE 80-bit extended
+ floating point)
+ in AIFF-C files only:
+ <compression type> (4 bytes)
+ <human-readable version of compression type> ("pstring")
+ SSND
+ <offset> (4 bytes, not used by this program)
+ <blocksize> (4 bytes, not used by this program)
+ <sound data>
+
+A pstring consists of 1 byte length, a string of characters, and 0 or 1
+byte pad to make the total length even.
+
+Usage.
+
+Reading AIFF files:
+ f = aifc.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().
+In some types of audio files, if the setpos() method is 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 AIFF files)
+ getcompname() -- returns human-readable version of
+ compression type ('not compressed' for AIFF files)
+ getparams() -- returns a tuple consisting of all of the
+ above in the above order
+ getmarkers() -- get the list of marks in the audio file or None
+ if there are no marks
+ getmark(id) -- get mark with the specified id (raises an error
+ if the mark does not exist)
+ 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(), the position given to setpos() and
+the position of marks are all 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 AIFF files:
+ f = aifc.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:
+ aiff() -- create an AIFF file (AIFF-C default)
+ aifc() -- create an AIFF-C file
+ 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
+ setmark(id, pos, name)
+ -- add specified mark to the list of marks
+ tell() -- return current position in output file (useful
+ in combination with setmark())
+ 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.
+Marks can be added anytime. If there are any marks, ypu must call
+close() after all frames have been written.
+The close() method is called automatically when the class instance
+is destroyed.
+
+When a file is opened with the extension '.aiff', an AIFF file is
+written, otherwise an AIFF-C file is written. This default can be
+changed by calling aiff() or aifc() before the first writeframes or
+writeframesraw.
+"""
+
+import struct
+import __builtin__
+
+__all__ = ["Error","open","openfp"]
+
+class Error(Exception):
+ pass
+
+_AIFC_version = 0xA2805140L # Version 1 of AIFF-C
+
+_skiplist = 'COMT', 'INST', 'MIDI', 'AESD', \
+ 'APPL', 'NAME', 'AUTH', '(c) ', 'ANNO'
+
+def _read_long(file):
+ try:
+ return struct.unpack('>l', file.read(4))[0]
+ except struct.error:
+ raise EOFError
+
+def _read_ulong(file):
+ try:
+ return struct.unpack('>L', file.read(4))[0]
+ except struct.error:
+ raise EOFError
+
+def _read_short(file):
+ try:
+ return struct.unpack('>h', file.read(2))[0]
+ except struct.error:
+ raise EOFError
+
+def _read_string(file):
+ length = ord(file.read(1))
+ if length == 0:
+ data = ''
+ else:
+ data = file.read(length)
+ if length & 1 == 0:
+ dummy = file.read(1)
+ return data
+
+_HUGE_VAL = 1.79769313486231e+308 # See <limits.h>
+
+def _read_float(f): # 10 bytes
+ expon = _read_short(f) # 2 bytes
+ sign = 1
+ if expon < 0:
+ sign = -1
+ expon = expon + 0x8000
+ himant = _read_ulong(f) # 4 bytes
+ lomant = _read_ulong(f) # 4 bytes
+ if expon == himant == lomant == 0:
+ f = 0.0
+ elif expon == 0x7FFF:
+ f = _HUGE_VAL
+ else:
+ expon = expon - 16383
+ f = (himant * 0x100000000L + lomant) * pow(2.0, expon - 63)
+ return sign * f
+
+def _write_short(f, x):
+ f.write(struct.pack('>h', x))
+
+def _write_long(f, x):
+ f.write(struct.pack('>L', x))
+
+def _write_string(f, s):
+ if len(s) > 255:
+ raise ValueError("string exceeds maximum pstring length")
+ f.write(chr(len(s)))
+ f.write(s)
+ if len(s) & 1 == 0:
+ f.write(chr(0))
+
+def _write_float(f, x):
+ import math
+ if x < 0:
+ sign = 0x8000
+ x = x * -1
+ else:
+ sign = 0
+ if x == 0:
+ expon = 0
+ himant = 0
+ lomant = 0
+ else:
+ fmant, expon = math.frexp(x)
+ if expon > 16384 or fmant >= 1: # Infinity or NaN
+ expon = sign|0x7FFF
+ himant = 0
+ lomant = 0
+ else: # Finite
+ expon = expon + 16382
+ if expon < 0: # denormalized
+ fmant = math.ldexp(fmant, expon)
+ expon = 0
+ expon = expon | sign
+ fmant = math.ldexp(fmant, 32)
+ fsmant = math.floor(fmant)
+ himant = long(fsmant)
+ fmant = math.ldexp(fmant - fsmant, 32)
+ fsmant = math.floor(fmant)
+ lomant = long(fsmant)
+ _write_short(f, expon)
+ _write_long(f, himant)
+ _write_long(f, lomant)
+
+from chunk import Chunk
+
+class Aifc_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
+ # _markers -- the marks in the audio file
+ # available through the getmarkers() and getmark()
+ # methods
+ # _soundpos -- the position in the audio stream
+ # available through the tell() method, set through the
+ # setpos() method
+ #
+ # These variables are used internally only:
+ # _version -- the AIFF-C version number
+ # _decomp -- the decompressor from builtin module cl
+ # _comm_chunk_read -- 1 iff the COMM chunk has been read
+ # _aifc -- 1 iff reading an AIFF-C file
+ # _ssnd_seek_needed -- 1 iff positioned correctly in audio
+ # file for readframes()
+ # _ssnd_chunk -- instantiation of a chunk class for the SSND chunk
+ # _framesize -- size of one frame in the file
+
+ def initfp(self, file):
+ self._version = 0
+ self._decomp = None
+ self._convert = None
+ self._markers = []
+ self._soundpos = 0
+ self._file = Chunk(file)
+ if self._file.getname() != 'FORM':
+ raise Error, 'file does not start with FORM id'
+ formdata = self._file.read(4)
+ if formdata == 'AIFF':
+ self._aifc = 0
+ elif formdata == 'AIFC':
+ self._aifc = 1
+ else:
+ raise Error, 'not an AIFF or AIFF-C file'
+ self._comm_chunk_read = 0
+ while 1:
+ self._ssnd_seek_needed = 1
+ try:
+ chunk = Chunk(self._file)
+ except EOFError:
+ break
+ chunkname = chunk.getname()
+ if chunkname == 'COMM':
+ self._read_comm_chunk(chunk)
+ self._comm_chunk_read = 1
+ elif chunkname == 'SSND':
+ self._ssnd_chunk = chunk
+ dummy = chunk.read(8)
+ self._ssnd_seek_needed = 0
+ elif chunkname == 'FVER':
+ self._version = _read_ulong(chunk)
+ elif chunkname == 'MARK':
+ self._readmark(chunk)
+ elif chunkname in _skiplist:
+ pass
+ else:
+ raise Error, 'unrecognized chunk type '+chunk.chunkname
+ chunk.skip()
+ if not self._comm_chunk_read or not self._ssnd_chunk:
+ raise Error, 'COMM chunk and/or SSND chunk missing'
+ if self._aifc and self._decomp:
+ import cl
+ params = [cl.ORIGINAL_FORMAT, 0,
+ cl.BITS_PER_COMPONENT, self._sampwidth * 8,
+ cl.FRAME_RATE, self._framerate]
+ if self._nchannels == 1:
+ params[1] = cl.MONO
+ elif self._nchannels == 2:
+ params[1] = cl.STEREO_INTERLEAVED
+ else:
+ raise Error, 'cannot compress more than 2 channels'
+ self._decomp.SetParams(params)
+
+ def __init__(self, f):
+ if type(f) == type(''):
+ f = __builtin__.open(f, 'rb')
+ # else, assume it is an open file object already
+ self.initfp(f)
+
+ #
+ # User visible methods.
+ #
+ def getfp(self):
+ return self._file
+
+ def rewind(self):
+ self._ssnd_seek_needed = 1
+ self._soundpos = 0
+
+ def close(self):
+ if self._decomp:
+ self._decomp.CloseDecompressor()
+ self._decomp = 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 getversion(self):
+## return self._version
+
+ def getparams(self):
+ return self.getnchannels(), self.getsampwidth(), \
+ self.getframerate(), self.getnframes(), \
+ self.getcomptype(), self.getcompname()
+
+ def getmarkers(self):
+ if len(self._markers) == 0:
+ return None
+ return self._markers
+
+ def getmark(self, id):
+ for marker in self._markers:
+ if id == marker[0]:
+ return marker
+ raise Error, 'marker %r does not exist' % (id,)
+
+ def setpos(self, pos):
+ if pos < 0 or pos > self._nframes:
+ raise Error, 'position not in range'
+ self._soundpos = pos
+ self._ssnd_seek_needed = 1
+
+ def readframes(self, nframes):
+ if self._ssnd_seek_needed:
+ self._ssnd_chunk.seek(0)
+ dummy = self._ssnd_chunk.read(8)
+ pos = self._soundpos * self._framesize
+ if pos:
+ self._ssnd_chunk.seek(pos + 8)
+ self._ssnd_seek_needed = 0
+ if nframes == 0:
+ return ''
+ data = self._ssnd_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 _decomp_data(self, data):
+ import cl
+ dummy = self._decomp.SetParam(cl.FRAME_BUFFER_SIZE,
+ len(data) * 2)
+ return self._decomp.Decompress(len(data) / self._nchannels,
+ data)
+
+ def _ulaw2lin(self, data):
+ import audioop
+ return audioop.ulaw2lin(data, 2)
+
+ def _adpcm2lin(self, data):
+ import audioop
+ if not hasattr(self, '_adpcmstate'):
+ # first time
+ self._adpcmstate = None
+ data, self._adpcmstate = audioop.adpcm2lin(data, 2,
+ self._adpcmstate)
+ return data
+
+ def _read_comm_chunk(self, chunk):
+ self._nchannels = _read_short(chunk)
+ self._nframes = _read_long(chunk)
+ self._sampwidth = (_read_short(chunk) + 7) / 8
+ self._framerate = int(_read_float(chunk))
+ self._framesize = self._nchannels * self._sampwidth
+ if self._aifc:
+ #DEBUG: SGI's soundeditor produces a bad size :-(
+ kludge = 0
+ if chunk.chunksize == 18:
+ kludge = 1
+ print 'Warning: bad COMM chunk size'
+ chunk.chunksize = 23
+ #DEBUG end
+ self._comptype = chunk.read(4)
+ #DEBUG start
+ if kludge:
+ length = ord(chunk.file.read(1))
+ if length & 1 == 0:
+ length = length + 1
+ chunk.chunksize = chunk.chunksize + length
+ chunk.file.seek(-1, 1)
+ #DEBUG end
+ self._compname = _read_string(chunk)
+ if self._comptype != 'NONE':
+ if self._comptype == 'G722':
+ try:
+ import audioop
+ except ImportError:
+ pass
+ else:
+ self._convert = self._adpcm2lin
+ self._framesize = self._framesize / 4
+ return
+ # for ULAW and ALAW try Compression Library
+ try:
+ import cl
+ except ImportError:
+ if self._comptype == 'ULAW':
+ try:
+ import audioop
+ self._convert = self._ulaw2lin
+ self._framesize = self._framesize / 2
+ return
+ except ImportError:
+ pass
+ raise Error, 'cannot read compressed AIFF-C files'
+ if self._comptype == 'ULAW':
+ scheme = cl.G711_ULAW
+ self._framesize = self._framesize / 2
+ elif self._comptype == 'ALAW':
+ scheme = cl.G711_ALAW
+ self._framesize = self._framesize / 2
+ else:
+ raise Error, 'unsupported compression type'
+ self._decomp = cl.OpenDecompressor(scheme)
+ self._convert = self._decomp_data
+ else:
+ self._comptype = 'NONE'
+ self._compname = 'not compressed'
+
+ def _readmark(self, chunk):
+ nmarkers = _read_short(chunk)
+ # Some files appear to contain invalid counts.
+ # Cope with this by testing for EOF.
+ try:
+ for i in range(nmarkers):
+ id = _read_short(chunk)
+ pos = _read_long(chunk)
+ name = _read_string(chunk)
+ if pos or name:
+ # some files appear to have
+ # dummy markers consisting of
+ # a position 0 and name ''
+ self._markers.append((id, pos, name))
+ except EOFError:
+ print 'Warning: MARK chunk contains only',
+ print len(self._markers),
+ if len(self._markers) == 1: print 'marker',
+ else: print 'markers',
+ print 'instead of', nmarkers
+
+class Aifc_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
+ # _aifc -- whether we're writing an AIFF-C file or an AIFF file
+ # set through the aifc() method, reset through the
+ # aiff() method
+ #
+ # These variables are used internally only:
+ # _version -- the AIFF-C version number
+ # _comp -- the compressor from builtin module cl
+ # _nframeswritten -- the number of audio frames actually written
+ # _datalength -- the size of the audio samples written to the header
+ # _datawritten -- the size of the audio samples actually written
+
+ def __init__(self, f):
+ if type(f) == type(''):
+ filename = f
+ f = __builtin__.open(f, 'wb')
+ else:
+ # else, assume it is an open file object already
+ filename = '???'
+ self.initfp(f)
+ if filename[-5:] == '.aiff':
+ self._aifc = 0
+ else:
+ self._aifc = 1
+
+ def initfp(self, file):
+ self._file = file
+ self._version = _AIFC_version
+ self._comptype = 'NONE'
+ self._compname = 'not compressed'
+ self._comp = None
+ self._convert = None
+ self._nchannels = 0
+ self._sampwidth = 0
+ self._framerate = 0
+ self._nframes = 0
+ self._nframeswritten = 0
+ self._datawritten = 0
+ self._datalength = 0
+ self._markers = []
+ self._marklength = 0
+ self._aifc = 1 # AIFF-C is default
+
+ def __del__(self):
+ if self._file:
+ self.close()
+
+ #
+ # User visible methods.
+ #
+ def aiff(self):
+ if self._nframeswritten:
+ raise Error, 'cannot change parameters after starting to write'
+ self._aifc = 0
+
+ def aifc(self):
+ if self._nframeswritten:
+ raise Error, 'cannot change parameters after starting to write'
+ self._aifc = 1
+
+ def setnchannels(self, nchannels):
+ if self._nframeswritten:
+ 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._nframeswritten:
+ 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._nframeswritten:
+ 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._nframeswritten:
+ 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._nframeswritten:
+ raise Error, 'cannot change parameters after starting to write'
+ if comptype not in ('NONE', 'ULAW', 'ALAW', 'G722'):
+ raise Error, 'unsupported compression type'
+ self._comptype = comptype
+ self._compname = compname
+
+ def getcomptype(self):
+ return self._comptype
+
+ def getcompname(self):
+ return self._compname
+
+## def setversion(self, version):
+## if self._nframeswritten:
+## raise Error, 'cannot change parameters after starting to write'
+## self._version = version
+
+ def setparams(self, info):
+ nchannels, sampwidth, framerate, nframes, comptype, compname = info
+ if self._nframeswritten:
+ raise Error, 'cannot change parameters after starting to write'
+ if comptype not in ('NONE', 'ULAW', 'ALAW', 'G722'):
+ raise Error, 'unsupported compression type'
+ 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):
+ if id <= 0:
+ raise Error, 'marker ID must be > 0'
+ if pos < 0:
+ raise Error, 'marker position must be >= 0'
+ if type(name) != type(''):
+ raise Error, 'marker name must be a string'
+ for i in range(len(self._markers)):
+ if id == self._markers[i][0]:
+ self._markers[i] = id, pos, name
+ return
+ self._markers.append((id, pos, name))
+
+ def getmark(self, id):
+ for marker in self._markers:
+ if id == marker[0]:
+ return marker
+ raise Error, 'marker %r does not exist' % (id,)
+
+ def getmarkers(self):
+ if len(self._markers) == 0:
+ return None
+ return self._markers
+
+ 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)
+ self._file.write(data)
+ self._nframeswritten = self._nframeswritten + nframes
+ self._datawritten = self._datawritten + len(data)
+
+ def writeframes(self, data):
+ self.writeframesraw(data)
+ if self._nframeswritten != self._nframes or \
+ self._datalength != self._datawritten:
+ self._patchheader()
+
+ def close(self):
+ self._ensure_header_written(0)
+ if self._datawritten & 1:
+ # quick pad to even size
+ self._file.write(chr(0))
+ self._datawritten = self._datawritten + 1
+ self._writemarkers()
+ if self._nframeswritten != self._nframes or \
+ self._datalength != self._datawritten or \
+ self._marklength:
+ self._patchheader()
+ if self._comp:
+ self._comp.CloseCompressor()
+ self._comp = None
+ self._file.flush()
+ self._file = None
+
+ #
+ # Internal methods.
+ #
+
+ def _comp_data(self, data):
+ import cl
+ dummy = self._comp.SetParam(cl.FRAME_BUFFER_SIZE, len(data))
+ dummy = self._comp.SetParam(cl.COMPRESSED_BUFFER_SIZE, len(data))
+ return self._comp.Compress(self._nframes, data)
+
+ def _lin2ulaw(self, data):
+ import audioop
+ return audioop.lin2ulaw(data, 2)
+
+ def _lin2adpcm(self, data):
+ import audioop
+ if not hasattr(self, '_adpcmstate'):
+ self._adpcmstate = None
+ data, self._adpcmstate = audioop.lin2adpcm(data, 2,
+ self._adpcmstate)
+ return data
+
+ def _ensure_header_written(self, datasize):
+ if not self._nframeswritten:
+ if self._comptype in ('ULAW', 'ALAW'):
+ if not self._sampwidth:
+ self._sampwidth = 2
+ if self._sampwidth != 2:
+ raise Error, 'sample width must be 2 when compressing with ULAW or ALAW'
+ if self._comptype == 'G722':
+ if not self._sampwidth:
+ self._sampwidth = 2
+ if self._sampwidth != 2:
+ raise Error, 'sample width must be 2 when compressing with G7.22 (ADPCM)'
+ 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 _init_compression(self):
+ if self._comptype == 'G722':
+ self._convert = self._lin2adpcm
+ return
+ try:
+ import cl
+ except ImportError:
+ if self._comptype == 'ULAW':
+ try:
+ import audioop
+ self._convert = self._lin2ulaw
+ return
+ except ImportError:
+ pass
+ raise Error, 'cannot write compressed AIFF-C files'
+ if self._comptype == 'ULAW':
+ scheme = cl.G711_ULAW
+ elif self._comptype == 'ALAW':
+ scheme = cl.G711_ALAW
+ else:
+ raise Error, 'unsupported compression type'
+ self._comp = cl.OpenCompressor(scheme)
+ params = [cl.ORIGINAL_FORMAT, 0,
+ cl.BITS_PER_COMPONENT, self._sampwidth * 8,
+ cl.FRAME_RATE, self._framerate,
+ cl.FRAME_BUFFER_SIZE, 100,
+ cl.COMPRESSED_BUFFER_SIZE, 100]
+ if self._nchannels == 1:
+ params[1] = cl.MONO
+ elif self._nchannels == 2:
+ params[1] = cl.STEREO_INTERLEAVED
+ else:
+ raise Error, 'cannot compress more than 2 channels'
+ self._comp.SetParams(params)
+ # the compressor produces a header which we ignore
+ dummy = self._comp.Compress(0, '')
+ self._convert = self._comp_data
+
+ def _write_header(self, initlength):
+ if self._aifc and self._comptype != 'NONE':
+ self._init_compression()
+ self._file.write('FORM')
+ if not self._nframes:
+ self._nframes = initlength / (self._nchannels * self._sampwidth)
+ self._datalength = self._nframes * self._nchannels * self._sampwidth
+ if self._datalength & 1:
+ self._datalength = self._datalength + 1
+ if self._aifc:
+ if self._comptype in ('ULAW', 'ALAW'):
+ self._datalength = self._datalength / 2
+ if self._datalength & 1:
+ self._datalength = self._datalength + 1
+ elif self._comptype == 'G722':
+ self._datalength = (self._datalength + 3) / 4
+ if self._datalength & 1:
+ self._datalength = self._datalength + 1
+ self._form_length_pos = self._file.tell()
+ commlength = self._write_form_length(self._datalength)
+ if self._aifc:
+ self._file.write('AIFC')
+ self._file.write('FVER')
+ _write_long(self._file, 4)
+ _write_long(self._file, self._version)
+ else:
+ self._file.write('AIFF')
+ self._file.write('COMM')
+ _write_long(self._file, commlength)
+ _write_short(self._file, self._nchannels)
+ self._nframes_pos = self._file.tell()
+ _write_long(self._file, self._nframes)
+ _write_short(self._file, self._sampwidth * 8)
+ _write_float(self._file, self._framerate)
+ if self._aifc:
+ self._file.write(self._comptype)
+ _write_string(self._file, self._compname)
+ self._file.write('SSND')
+ self._ssnd_length_pos = self._file.tell()
+ _write_long(self._file, self._datalength + 8)
+ _write_long(self._file, 0)
+ _write_long(self._file, 0)
+
+ def _write_form_length(self, datalength):
+ if self._aifc:
+ commlength = 18 + 5 + len(self._compname)
+ if commlength & 1:
+ commlength = commlength + 1
+ verslength = 12
+ else:
+ commlength = 18
+ verslength = 0
+ _write_long(self._file, 4 + verslength + self._marklength + \
+ 8 + commlength + 16 + datalength)
+ return commlength
+
+ def _patchheader(self):
+ curpos = self._file.tell()
+ if self._datawritten & 1:
+ datalength = self._datawritten + 1
+ self._file.write(chr(0))
+ else:
+ datalength = self._datawritten
+ if datalength == self._datalength and \
+ self._nframes == self._nframeswritten and \
+ self._marklength == 0:
+ self._file.seek(curpos, 0)
+ return
+ self._file.seek(self._form_length_pos, 0)
+ dummy = self._write_form_length(datalength)
+ self._file.seek(self._nframes_pos, 0)
+ _write_long(self._file, self._nframeswritten)
+ self._file.seek(self._ssnd_length_pos, 0)
+ _write_long(self._file, datalength + 8)
+ self._file.seek(curpos, 0)
+ self._nframes = self._nframeswritten
+ self._datalength = datalength
+
+ def _writemarkers(self):
+ if len(self._markers) == 0:
+ return
+ self._file.write('MARK')
+ length = 2
+ for marker in self._markers:
+ id, pos, name = marker
+ length = length + len(name) + 1 + 6
+ if len(name) & 1 == 0:
+ length = length + 1
+ _write_long(self._file, length)
+ self._marklength = length + 8
+ _write_short(self._file, len(self._markers))
+ for marker in self._markers:
+ id, pos, name = marker
+ _write_short(self._file, id)
+ _write_long(self._file, pos)
+ _write_string(self._file, name)
+
+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 Aifc_read(f)
+ elif mode in ('w', 'wb'):
+ return Aifc_write(f)
+ else:
+ raise Error, "mode must be 'r', 'rb', 'w', or 'wb'"
+
+openfp = open # B/W compatibility
+
+if __name__ == '__main__':
+ import sys
+ if not sys.argv[1:]:
+ sys.argv.append('/usr/demos/data/audio/bach.aiff')
+ fn = sys.argv[1]
+ f = open(fn, 'r')
+ print "Reading", fn
+ print "nchannels =", f.getnchannels()
+ print "nframes =", f.getnframes()
+ print "sampwidth =", f.getsampwidth()
+ print "framerate =", f.getframerate()
+ print "comptype =", f.getcomptype()
+ print "compname =", f.getcompname()
+ if sys.argv[2:]:
+ gn = sys.argv[2]
+ print "Writing", gn
+ g = open(gn, 'w')
+ g.setparams(f.getparams())
+ while 1:
+ data = f.readframes(1024)
+ if not data:
+ break
+ g.writeframes(data)
+ g.close()
+ f.close()
+ print "Done."