| # 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 postion 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__ |
| |
| Error = 'wave.Error' |
| |
| 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 |
| |
| def _read_long(file): |
| x = 0L |
| for i in range(4): |
| byte = file.read(1) |
| if byte == '': |
| raise EOFError |
| x = x + (ord(byte) << (8 * i)) |
| if x >= 0x80000000L: |
| x = x - 0x100000000L |
| return int(x) |
| |
| def _read_ulong(file): |
| x = 0L |
| for i in range(4): |
| byte = file.read(1) |
| if byte == '': |
| raise EOFError |
| x = x + (ord(byte) << (8 * i)) |
| return x |
| |
| def _read_short(file): |
| x = 0 |
| for i in range(2): |
| byte = file.read(1) |
| if byte == '': |
| raise EOFError |
| x = x + (ord(byte) << (8 * i)) |
| if x >= 0x8000: |
| x = x - 0x10000 |
| return x |
| |
| def _write_short(f, x): |
| d, m = divmod(x, 256) |
| f.write(chr(m)) |
| f.write(chr(d)) |
| |
| def _write_long(f, x): |
| if x < 0: |
| x = x + 0x100000000L |
| for i in range(4): |
| d, m = divmod(x, 256) |
| f.write(chr(int(m))) |
| x = d |
| |
| class Chunk: |
| def __init__(self, file): |
| self.file = file |
| self.chunkname = self.file.read(4) |
| if len(self.chunkname) < 4: |
| raise EOFError |
| self.chunksize = _read_long(self.file) |
| self.size_read = 0 |
| self.offset = self.file.tell() |
| |
| def rewind(self): |
| self.file.seek(self.offset, 0) |
| self.size_read = 0 |
| |
| def setpos(self, pos): |
| if pos < 0 or pos > self.chunksize: |
| raise RuntimeError |
| self.file.seek(self.offset + pos, 0) |
| self.size_read = pos |
| |
| def read(self, length): |
| if self.size_read >= self.chunksize: |
| return '' |
| if length > self.chunksize - self.size_read: |
| length = self.chunksize - self.size_read |
| data = self.file.read(length) |
| self.size_read = self.size_read + len(data) |
| return data |
| |
| def skip(self): |
| try: |
| self.file.seek(self.chunksize - self.size_read, 1) |
| except RuntimeError: |
| while self.size_read < self.chunksize: |
| dummy = self.read(8192) |
| if not dummy: |
| raise EOFError |
| |
| 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 |
| |
| ## access _file, _nchannels, _nframes, _sampwidth, _framerate, \ |
| ## _comptype, _compname, _soundpos, \ |
| ## _fmt_chunk_read, _data_seek_needed, \ |
| ## _data_chunk, _framesize: private |
| |
| def initfp(self, file): |
| self._file = file |
| self._convert = None |
| self._soundpos = 0 |
| form = self._file.read(4) |
| if form != 'RIFF': |
| raise Error, 'file does not start with RIFF id' |
| formlength = _read_long(self._file) |
| if formlength <= 0: |
| raise Error, 'invalid FORM chunk data size' |
| formdata = self._file.read(4) |
| formlength = formlength - 4 |
| if formdata != 'WAVE': |
| raise Error, 'not a WAVE file' |
| self._fmt_chunk_read = 0 |
| while formlength > 0: |
| self._data_seek_needed = 1 |
| chunk = Chunk(self._file) |
| if chunk.chunkname == 'fmt ': |
| self._read_fmt_chunk(chunk) |
| self._fmt_chunk_read = 1 |
| elif chunk.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 |
| formlength = formlength - 8 - chunk.chunksize |
| if formlength > 0: |
| 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): |
| if type(f) == type(''): |
| f = __builtin__.open(f, 'rb') |
| # else, assume it is an open file object already |
| self.initfp(f) |
| |
| def __del__(self): |
| if self._file: |
| 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): |
| 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.rewind() |
| pos = self._soundpos * self._framesize |
| if pos: |
| self._data_chunk.setpos(pos) |
| 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 |
| data = array.array(_array_fmts[self._sampwidth]) |
| nitems = nframes * self._nchannels |
| if nitems * self._sampwidth > self._data_chunk.chunksize - self._data_chunk.size_read: |
| nitems = (self._data_chunk.chunksize - self._data_chunk.size_read) / self._sampwidth |
| data.fromfile(self._data_chunk.file, nitems) |
| self._data_chunk.size_read = self._data_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. |
| # |
| ## access *: private |
| |
| def _read_fmt_chunk(self, chunk): |
| wFormatTag = _read_short(chunk) |
| self._nchannels = _read_short(chunk) |
| self._framerate = _read_long(chunk) |
| dwAvgBytesPerSec = _read_long(chunk) |
| wBlockAlign = _read_short(chunk) |
| if wFormatTag == WAVE_FORMAT_PCM: |
| self._sampwidth = (_read_short(chunk) + 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 |
| |
| ## access _file, _comptype, _compname, _nchannels, _sampwidth, \ |
| ## _framerate, _nframes, _nframeswritten, \ |
| ## _datalength, _datawritten: private |
| |
| def __init__(self, f): |
| if type(f) == type(''): |
| f = __builtin__.open(f, 'wb') |
| 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): |
| if self._file: |
| 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): |
| self._ensure_header_written(0) |
| if self._datalength != self._datawritten: |
| self._patchheader() |
| self._file.flush() |
| self._file = None |
| |
| # |
| # Internal methods. |
| # |
| ## access *: private |
| |
| 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() |
| _write_long(self._file, 36 + self._datalength) |
| self._file.write('WAVE') |
| self._file.write('fmt ') |
| _write_long(self._file, 16) |
| _write_short(self._file, WAVE_FORMAT_PCM) |
| _write_short(self._file, self._nchannels) |
| _write_long(self._file, self._framerate) |
| _write_long(self._file, self._nchannels * self._framerate * self._sampwidth) |
| _write_short(self._file, self._nchannels * self._sampwidth) |
| _write_short(self._file, self._sampwidth * 8) |
| self._file.write('data') |
| self._data_length_pos = self._file.tell() |
| _write_long(self._file, self._datalength) |
| |
| def _patchheader(self): |
| if self._datawritten == self._datalength: |
| return |
| curpos = self._file.tell() |
| self._file.seek(self._form_length_pos, 0) |
| _write_long(self._file, 36 + self._datawritten) |
| self._file.seek(self._data_length_pos, 0) |
| _write_long(self._file, self._datawritten) |
| self._file.seek(curpos, 0) |
| self._datalength = self._datawritten |
| |
| def open(f, mode): |
| 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 |