| # 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 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()-- 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(nchannels, sampwidth, framerate, nframes, comptype, compname) |
| #-- 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' |
| |
| def _read_long(file): |
| x=0L |
| for iin range(4): |
| byte= file.read(1) |
| if byte=='': |
| raiseEOFError |
| x= x+(ord(byte)<<(8* i)) |
| if x>=0x80000000L: |
| x= x-0x100000000L |
| return int(x) |
| |
| def _read_ulong(file): |
| x=0L |
| for iin range(4): |
| byte= file.read(1) |
| if byte=='': |
| raiseEOFError |
| x= x+(ord(byte)<<(8* i)) |
| return x |
| |
| def _read_short(file): |
| x=0 |
| for iin range(2): |
| byte= file.read(1) |
| if byte=='': |
| raiseEOFError |
| 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 iin range(4): |
| d, m= divmod(x,256) |
| f.write(chr(int(m))) |
| x= d |
| |
| classChunk: |
| def __init__(self, file): |
| self.file= file |
| self.chunkname= self.file.read(4) |
| if len(self.chunkname)<4: |
| raiseEOFError |
| 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<0or pos> self.chunksize: |
| raiseRuntimeError |
| 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) |
| exceptRuntimeError: |
| while self.size_read< self.chunksize: |
| dummy= self.read(8192) |
| ifnot dummy: |
| raiseEOFError |
| |
| classWave_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': |
| raiseError,'file does not start with RIFF id' |
| formlength= _read_long(self._file) |
| if formlength<=0: |
| raiseError,'invalid FORM chunk data size' |
| formdata= self._file.read(4) |
| formlength= formlength-4 |
| if formdata!='WAVE': |
| raiseError,'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': |
| ifnot self._fmt_chunk_read: |
| raiseError,'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() |
| ifnot self._fmt_chunk_readornot self._data_chunk: |
| raiseError,'fmt chunk and/or data chunk missing' |
| |
| def __init__(self, f): |
| if type(f)== type(''): |
| f= __builtin__.open(f,'r') |
| # 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): |
| returnNone |
| |
| def getmark(self, id): |
| raiseError,'no marks' |
| |
| def setpos(self, pos): |
| if pos<0or pos> self._nframes: |
| raiseError,'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: |
| # 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._convertand 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: |
| raiseError,'unknown format' |
| self._framesize= self._nchannels* self._sampwidth |
| self._comptype='NONE' |
| self._compname='not compressed' |
| |
| classWave_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,'w') |
| 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: |
| raiseError,'cannot change parameters after starting to write' |
| if nchannels<1: |
| raiseError,'bad # of channels' |
| self._nchannels= nchannels |
| |
| def getnchannels(self): |
| ifnot self._nchannels: |
| raiseError,'number of channels not set' |
| return self._nchannels |
| |
| def setsampwidth(self, sampwidth): |
| if self._datawritten: |
| raiseError,'cannot change parameters after starting to write' |
| if sampwidth<1or sampwidth>4: |
| raiseError,'bad sample width' |
| self._sampwidth= sampwidth |
| |
| def getsampwidth(self): |
| ifnot self._sampwidth: |
| raiseError,'sample width not set' |
| return self._sampwidth |
| |
| def setframerate(self, framerate): |
| if self._datawritten: |
| raiseError,'cannot change parameters after starting to write' |
| if framerate<=0: |
| raiseError,'bad frame rate' |
| self._framerate= framerate |
| |
| def getframerate(self): |
| ifnot self._framerate: |
| raiseError,'frame rate not set' |
| return self._framerate |
| |
| def setnframes(self, nframes): |
| if self._datawritten: |
| raiseError,'cannot change parameters after starting to write' |
| self._nframes= nframes |
| |
| def getnframes(self): |
| return self._nframeswritten |
| |
| def setcomptype(self, comptype, compname): |
| if self._datawritten: |
| raiseError,'cannot change parameters after starting to write' |
| if comptypenotin('NONE',): |
| raiseError,'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: |
| raiseError,'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): |
| ifnot self._nchannelsornot self._sampwidthornot self._framerate: |
| raiseError,'not all parameters set' |
| return self._nchannels, self._sampwidth, self._framerate, \ |
| self._nframes, self._comptype, self._compname |
| |
| def setmark(self, id, pos, name): |
| raiseError,'setmark() not supported' |
| |
| def getmark(self, id): |
| raiseError,'no marks' |
| |
| def getmarkers(self): |
| returnNone |
| |
| 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: |
| 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): |
| ifnot self._datawritten: |
| ifnot self._nchannels: |
| raiseError,'# channels not specified' |
| ifnot self._sampwidth: |
| raiseError,'sample width not specified' |
| ifnot self._framerate: |
| raiseError,'sampling rate not specified' |
| self._write_header(datasize) |
| |
| def _write_header(self, initlength): |
| self._file.write('RIFF') |
| ifnot 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(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=='r': |
| returnWave_read(f) |
| elif mode=='w': |
| returnWave_write(f) |
| else: |
| raiseError,"mode must be 'r' or 'w'" |
| |
| openfp= open# B/W compatibility |
