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Diffstat (limited to 'lib/python2.7/aifc.py')
| -rw-r--r-- | lib/python2.7/aifc.py | 975 |
1 files changed, 0 insertions, 975 deletions
diff --git a/lib/python2.7/aifc.py b/lib/python2.7/aifc.py deleted file mode 100644 index a0cfe5f..0000000 --- a/lib/python2.7/aifc.py +++ /dev/null @@ -1,975 +0,0 @@ -"""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 - -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_ushort(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_ushort(f, x): - f.write(struct.pack('>H', x)) - -def _write_long(f, x): - f.write(struct.pack('>l', x)) - -def _write_ulong(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(struct.pack('B', 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 or fmant != fmant: # 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_ushort(f, expon) - _write_ulong(f, himant) - _write_ulong(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 = file - chunk = Chunk(file) - if chunk.getname() != 'FORM': - raise Error, 'file does not start with FORM id' - formdata = chunk.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) - 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.close() - - 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): - if self._file is None: - return - try: - 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 - finally: - # Prevent ref cycles - self._convert = None - f = self._file - self._file = None - f.close() - - # - # 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_ulong(self._file, 4) - _write_ulong(self._file, self._version) - else: - self._file.write('AIFF') - self._file.write('COMM') - _write_ulong(self._file, commlength) - _write_short(self._file, self._nchannels) - self._nframes_pos = self._file.tell() - _write_ulong(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_ulong(self._file, self._datalength + 8) - _write_ulong(self._file, 0) - _write_ulong(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_ulong(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_ulong(self._file, self._nframeswritten) - self._file.seek(self._ssnd_length_pos, 0) - _write_ulong(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_ulong(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_ulong(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." |