Jingwen Chen | 475b3cc | 2021-01-05 21:45:16 -0500 | [diff] [blame^] | 1 | """Stuff to parse WAVE files. |
| 2 | |
| 3 | Usage. |
| 4 | |
| 5 | Reading WAVE files: |
| 6 | f = wave.open(file, 'r') |
| 7 | where file is either the name of a file or an open file pointer. |
| 8 | The open file pointer must have methods read(), seek(), and close(). |
| 9 | When the setpos() and rewind() methods are not used, the seek() |
| 10 | method is not necessary. |
| 11 | |
| 12 | This returns an instance of a class with the following public methods: |
| 13 | getnchannels() -- returns number of audio channels (1 for |
| 14 | mono, 2 for stereo) |
| 15 | getsampwidth() -- returns sample width in bytes |
| 16 | getframerate() -- returns sampling frequency |
| 17 | getnframes() -- returns number of audio frames |
| 18 | getcomptype() -- returns compression type ('NONE' for linear samples) |
| 19 | getcompname() -- returns human-readable version of |
| 20 | compression type ('not compressed' linear samples) |
| 21 | getparams() -- returns a namedtuple consisting of all of the |
| 22 | above in the above order |
| 23 | getmarkers() -- returns None (for compatibility with the |
| 24 | aifc module) |
| 25 | getmark(id) -- raises an error since the mark does not |
| 26 | exist (for compatibility with the aifc module) |
| 27 | readframes(n) -- returns at most n frames of audio |
| 28 | rewind() -- rewind to the beginning of the audio stream |
| 29 | setpos(pos) -- seek to the specified position |
| 30 | tell() -- return the current position |
| 31 | close() -- close the instance (make it unusable) |
| 32 | The position returned by tell() and the position given to setpos() |
| 33 | are compatible and have nothing to do with the actual position in the |
| 34 | file. |
| 35 | The close() method is called automatically when the class instance |
| 36 | is destroyed. |
| 37 | |
| 38 | Writing WAVE files: |
| 39 | f = wave.open(file, 'w') |
| 40 | where file is either the name of a file or an open file pointer. |
| 41 | The open file pointer must have methods write(), tell(), seek(), and |
| 42 | close(). |
| 43 | |
| 44 | This returns an instance of a class with the following public methods: |
| 45 | setnchannels(n) -- set the number of channels |
| 46 | setsampwidth(n) -- set the sample width |
| 47 | setframerate(n) -- set the frame rate |
| 48 | setnframes(n) -- set the number of frames |
| 49 | setcomptype(type, name) |
| 50 | -- set the compression type and the |
| 51 | human-readable compression type |
| 52 | setparams(tuple) |
| 53 | -- set all parameters at once |
| 54 | tell() -- return current position in output file |
| 55 | writeframesraw(data) |
| 56 | -- write audio frames without patching up the |
| 57 | file header |
| 58 | writeframes(data) |
| 59 | -- write audio frames and patch up the file header |
| 60 | close() -- patch up the file header and close the |
| 61 | output file |
| 62 | You should set the parameters before the first writeframesraw or |
| 63 | writeframes. The total number of frames does not need to be set, |
| 64 | but when it is set to the correct value, the header does not have to |
| 65 | be patched up. |
| 66 | It is best to first set all parameters, perhaps possibly the |
| 67 | compression type, and then write audio frames using writeframesraw. |
| 68 | When all frames have been written, either call writeframes(b'') or |
| 69 | close() to patch up the sizes in the header. |
| 70 | The close() method is called automatically when the class instance |
| 71 | is destroyed. |
| 72 | """ |
| 73 | |
| 74 | import builtins |
| 75 | |
| 76 | __all__ = ["open", "openfp", "Error", "Wave_read", "Wave_write"] |
| 77 | |
| 78 | class Error(Exception): |
| 79 | pass |
| 80 | |
| 81 | WAVE_FORMAT_PCM = 0x0001 |
| 82 | |
| 83 | _array_fmts = None, 'b', 'h', None, 'i' |
| 84 | |
| 85 | import audioop |
| 86 | import struct |
| 87 | import sys |
| 88 | from chunk import Chunk |
| 89 | from collections import namedtuple |
| 90 | import warnings |
| 91 | |
| 92 | _wave_params = namedtuple('_wave_params', |
| 93 | 'nchannels sampwidth framerate nframes comptype compname') |
| 94 | |
| 95 | class Wave_read: |
| 96 | """Variables used in this class: |
| 97 | |
| 98 | These variables are available to the user though appropriate |
| 99 | methods of this class: |
| 100 | _file -- the open file with methods read(), close(), and seek() |
| 101 | set through the __init__() method |
| 102 | _nchannels -- the number of audio channels |
| 103 | available through the getnchannels() method |
| 104 | _nframes -- the number of audio frames |
| 105 | available through the getnframes() method |
| 106 | _sampwidth -- the number of bytes per audio sample |
| 107 | available through the getsampwidth() method |
| 108 | _framerate -- the sampling frequency |
| 109 | available through the getframerate() method |
| 110 | _comptype -- the AIFF-C compression type ('NONE' if AIFF) |
| 111 | available through the getcomptype() method |
| 112 | _compname -- the human-readable AIFF-C compression type |
| 113 | available through the getcomptype() method |
| 114 | _soundpos -- the position in the audio stream |
| 115 | available through the tell() method, set through the |
| 116 | setpos() method |
| 117 | |
| 118 | These variables are used internally only: |
| 119 | _fmt_chunk_read -- 1 iff the FMT chunk has been read |
| 120 | _data_seek_needed -- 1 iff positioned correctly in audio |
| 121 | file for readframes() |
| 122 | _data_chunk -- instantiation of a chunk class for the DATA chunk |
| 123 | _framesize -- size of one frame in the file |
| 124 | """ |
| 125 | |
| 126 | def initfp(self, file): |
| 127 | self._convert = None |
| 128 | self._soundpos = 0 |
| 129 | self._file = Chunk(file, bigendian = 0) |
| 130 | if self._file.getname() != b'RIFF': |
| 131 | raise Error('file does not start with RIFF id') |
| 132 | if self._file.read(4) != b'WAVE': |
| 133 | raise Error('not a WAVE file') |
| 134 | self._fmt_chunk_read = 0 |
| 135 | self._data_chunk = None |
| 136 | while 1: |
| 137 | self._data_seek_needed = 1 |
| 138 | try: |
| 139 | chunk = Chunk(self._file, bigendian = 0) |
| 140 | except EOFError: |
| 141 | break |
| 142 | chunkname = chunk.getname() |
| 143 | if chunkname == b'fmt ': |
| 144 | self._read_fmt_chunk(chunk) |
| 145 | self._fmt_chunk_read = 1 |
| 146 | elif chunkname == b'data': |
| 147 | if not self._fmt_chunk_read: |
| 148 | raise Error('data chunk before fmt chunk') |
| 149 | self._data_chunk = chunk |
| 150 | self._nframes = chunk.chunksize // self._framesize |
| 151 | self._data_seek_needed = 0 |
| 152 | break |
| 153 | chunk.skip() |
| 154 | if not self._fmt_chunk_read or not self._data_chunk: |
| 155 | raise Error('fmt chunk and/or data chunk missing') |
| 156 | |
| 157 | def __init__(self, f): |
| 158 | self._i_opened_the_file = None |
| 159 | if isinstance(f, str): |
| 160 | f = builtins.open(f, 'rb') |
| 161 | self._i_opened_the_file = f |
| 162 | # else, assume it is an open file object already |
| 163 | try: |
| 164 | self.initfp(f) |
| 165 | except: |
| 166 | if self._i_opened_the_file: |
| 167 | f.close() |
| 168 | raise |
| 169 | |
| 170 | def __del__(self): |
| 171 | self.close() |
| 172 | |
| 173 | def __enter__(self): |
| 174 | return self |
| 175 | |
| 176 | def __exit__(self, *args): |
| 177 | self.close() |
| 178 | |
| 179 | # |
| 180 | # User visible methods. |
| 181 | # |
| 182 | def getfp(self): |
| 183 | return self._file |
| 184 | |
| 185 | def rewind(self): |
| 186 | self._data_seek_needed = 1 |
| 187 | self._soundpos = 0 |
| 188 | |
| 189 | def close(self): |
| 190 | self._file = None |
| 191 | file = self._i_opened_the_file |
| 192 | if file: |
| 193 | self._i_opened_the_file = None |
| 194 | file.close() |
| 195 | |
| 196 | def tell(self): |
| 197 | return self._soundpos |
| 198 | |
| 199 | def getnchannels(self): |
| 200 | return self._nchannels |
| 201 | |
| 202 | def getnframes(self): |
| 203 | return self._nframes |
| 204 | |
| 205 | def getsampwidth(self): |
| 206 | return self._sampwidth |
| 207 | |
| 208 | def getframerate(self): |
| 209 | return self._framerate |
| 210 | |
| 211 | def getcomptype(self): |
| 212 | return self._comptype |
| 213 | |
| 214 | def getcompname(self): |
| 215 | return self._compname |
| 216 | |
| 217 | def getparams(self): |
| 218 | return _wave_params(self.getnchannels(), self.getsampwidth(), |
| 219 | self.getframerate(), self.getnframes(), |
| 220 | self.getcomptype(), self.getcompname()) |
| 221 | |
| 222 | def getmarkers(self): |
| 223 | return None |
| 224 | |
| 225 | def getmark(self, id): |
| 226 | raise Error('no marks') |
| 227 | |
| 228 | def setpos(self, pos): |
| 229 | if pos < 0 or pos > self._nframes: |
| 230 | raise Error('position not in range') |
| 231 | self._soundpos = pos |
| 232 | self._data_seek_needed = 1 |
| 233 | |
| 234 | def readframes(self, nframes): |
| 235 | if self._data_seek_needed: |
| 236 | self._data_chunk.seek(0, 0) |
| 237 | pos = self._soundpos * self._framesize |
| 238 | if pos: |
| 239 | self._data_chunk.seek(pos, 0) |
| 240 | self._data_seek_needed = 0 |
| 241 | if nframes == 0: |
| 242 | return b'' |
| 243 | data = self._data_chunk.read(nframes * self._framesize) |
| 244 | if self._sampwidth != 1 and sys.byteorder == 'big': |
| 245 | data = audioop.byteswap(data, self._sampwidth) |
| 246 | if self._convert and data: |
| 247 | data = self._convert(data) |
| 248 | self._soundpos = self._soundpos + len(data) // (self._nchannels * self._sampwidth) |
| 249 | return data |
| 250 | |
| 251 | # |
| 252 | # Internal methods. |
| 253 | # |
| 254 | |
| 255 | def _read_fmt_chunk(self, chunk): |
| 256 | try: |
| 257 | wFormatTag, self._nchannels, self._framerate, dwAvgBytesPerSec, wBlockAlign = struct.unpack_from('<HHLLH', chunk.read(14)) |
| 258 | except struct.error: |
| 259 | raise EOFError from None |
| 260 | if wFormatTag == WAVE_FORMAT_PCM: |
| 261 | try: |
| 262 | sampwidth = struct.unpack_from('<H', chunk.read(2))[0] |
| 263 | except struct.error: |
| 264 | raise EOFError from None |
| 265 | self._sampwidth = (sampwidth + 7) // 8 |
| 266 | if not self._sampwidth: |
| 267 | raise Error('bad sample width') |
| 268 | else: |
| 269 | raise Error('unknown format: %r' % (wFormatTag,)) |
| 270 | if not self._nchannels: |
| 271 | raise Error('bad # of channels') |
| 272 | self._framesize = self._nchannels * self._sampwidth |
| 273 | self._comptype = 'NONE' |
| 274 | self._compname = 'not compressed' |
| 275 | |
| 276 | class Wave_write: |
| 277 | """Variables used in this class: |
| 278 | |
| 279 | These variables are user settable through appropriate methods |
| 280 | of this class: |
| 281 | _file -- the open file with methods write(), close(), tell(), seek() |
| 282 | set through the __init__() method |
| 283 | _comptype -- the AIFF-C compression type ('NONE' in AIFF) |
| 284 | set through the setcomptype() or setparams() method |
| 285 | _compname -- the human-readable AIFF-C compression type |
| 286 | set through the setcomptype() or setparams() method |
| 287 | _nchannels -- the number of audio channels |
| 288 | set through the setnchannels() or setparams() method |
| 289 | _sampwidth -- the number of bytes per audio sample |
| 290 | set through the setsampwidth() or setparams() method |
| 291 | _framerate -- the sampling frequency |
| 292 | set through the setframerate() or setparams() method |
| 293 | _nframes -- the number of audio frames written to the header |
| 294 | set through the setnframes() or setparams() method |
| 295 | |
| 296 | These variables are used internally only: |
| 297 | _datalength -- the size of the audio samples written to the header |
| 298 | _nframeswritten -- the number of frames actually written |
| 299 | _datawritten -- the size of the audio samples actually written |
| 300 | """ |
| 301 | |
| 302 | def __init__(self, f): |
| 303 | self._i_opened_the_file = None |
| 304 | if isinstance(f, str): |
| 305 | f = builtins.open(f, 'wb') |
| 306 | self._i_opened_the_file = f |
| 307 | try: |
| 308 | self.initfp(f) |
| 309 | except: |
| 310 | if self._i_opened_the_file: |
| 311 | f.close() |
| 312 | raise |
| 313 | |
| 314 | def initfp(self, file): |
| 315 | self._file = file |
| 316 | self._convert = None |
| 317 | self._nchannels = 0 |
| 318 | self._sampwidth = 0 |
| 319 | self._framerate = 0 |
| 320 | self._nframes = 0 |
| 321 | self._nframeswritten = 0 |
| 322 | self._datawritten = 0 |
| 323 | self._datalength = 0 |
| 324 | self._headerwritten = False |
| 325 | |
| 326 | def __del__(self): |
| 327 | self.close() |
| 328 | |
| 329 | def __enter__(self): |
| 330 | return self |
| 331 | |
| 332 | def __exit__(self, *args): |
| 333 | self.close() |
| 334 | |
| 335 | # |
| 336 | # User visible methods. |
| 337 | # |
| 338 | def setnchannels(self, nchannels): |
| 339 | if self._datawritten: |
| 340 | raise Error('cannot change parameters after starting to write') |
| 341 | if nchannels < 1: |
| 342 | raise Error('bad # of channels') |
| 343 | self._nchannels = nchannels |
| 344 | |
| 345 | def getnchannels(self): |
| 346 | if not self._nchannels: |
| 347 | raise Error('number of channels not set') |
| 348 | return self._nchannels |
| 349 | |
| 350 | def setsampwidth(self, sampwidth): |
| 351 | if self._datawritten: |
| 352 | raise Error('cannot change parameters after starting to write') |
| 353 | if sampwidth < 1 or sampwidth > 4: |
| 354 | raise Error('bad sample width') |
| 355 | self._sampwidth = sampwidth |
| 356 | |
| 357 | def getsampwidth(self): |
| 358 | if not self._sampwidth: |
| 359 | raise Error('sample width not set') |
| 360 | return self._sampwidth |
| 361 | |
| 362 | def setframerate(self, framerate): |
| 363 | if self._datawritten: |
| 364 | raise Error('cannot change parameters after starting to write') |
| 365 | if framerate <= 0: |
| 366 | raise Error('bad frame rate') |
| 367 | self._framerate = int(round(framerate)) |
| 368 | |
| 369 | def getframerate(self): |
| 370 | if not self._framerate: |
| 371 | raise Error('frame rate not set') |
| 372 | return self._framerate |
| 373 | |
| 374 | def setnframes(self, nframes): |
| 375 | if self._datawritten: |
| 376 | raise Error('cannot change parameters after starting to write') |
| 377 | self._nframes = nframes |
| 378 | |
| 379 | def getnframes(self): |
| 380 | return self._nframeswritten |
| 381 | |
| 382 | def setcomptype(self, comptype, compname): |
| 383 | if self._datawritten: |
| 384 | raise Error('cannot change parameters after starting to write') |
| 385 | if comptype not in ('NONE',): |
| 386 | raise Error('unsupported compression type') |
| 387 | self._comptype = comptype |
| 388 | self._compname = compname |
| 389 | |
| 390 | def getcomptype(self): |
| 391 | return self._comptype |
| 392 | |
| 393 | def getcompname(self): |
| 394 | return self._compname |
| 395 | |
| 396 | def setparams(self, params): |
| 397 | nchannels, sampwidth, framerate, nframes, comptype, compname = params |
| 398 | if self._datawritten: |
| 399 | raise Error('cannot change parameters after starting to write') |
| 400 | self.setnchannels(nchannels) |
| 401 | self.setsampwidth(sampwidth) |
| 402 | self.setframerate(framerate) |
| 403 | self.setnframes(nframes) |
| 404 | self.setcomptype(comptype, compname) |
| 405 | |
| 406 | def getparams(self): |
| 407 | if not self._nchannels or not self._sampwidth or not self._framerate: |
| 408 | raise Error('not all parameters set') |
| 409 | return _wave_params(self._nchannels, self._sampwidth, self._framerate, |
| 410 | self._nframes, self._comptype, self._compname) |
| 411 | |
| 412 | def setmark(self, id, pos, name): |
| 413 | raise Error('setmark() not supported') |
| 414 | |
| 415 | def getmark(self, id): |
| 416 | raise Error('no marks') |
| 417 | |
| 418 | def getmarkers(self): |
| 419 | return None |
| 420 | |
| 421 | def tell(self): |
| 422 | return self._nframeswritten |
| 423 | |
| 424 | def writeframesraw(self, data): |
| 425 | if not isinstance(data, (bytes, bytearray)): |
| 426 | data = memoryview(data).cast('B') |
| 427 | self._ensure_header_written(len(data)) |
| 428 | nframes = len(data) // (self._sampwidth * self._nchannels) |
| 429 | if self._convert: |
| 430 | data = self._convert(data) |
| 431 | if self._sampwidth != 1 and sys.byteorder == 'big': |
| 432 | data = audioop.byteswap(data, self._sampwidth) |
| 433 | self._file.write(data) |
| 434 | self._datawritten += len(data) |
| 435 | self._nframeswritten = self._nframeswritten + nframes |
| 436 | |
| 437 | def writeframes(self, data): |
| 438 | self.writeframesraw(data) |
| 439 | if self._datalength != self._datawritten: |
| 440 | self._patchheader() |
| 441 | |
| 442 | def close(self): |
| 443 | try: |
| 444 | if self._file: |
| 445 | self._ensure_header_written(0) |
| 446 | if self._datalength != self._datawritten: |
| 447 | self._patchheader() |
| 448 | self._file.flush() |
| 449 | finally: |
| 450 | self._file = None |
| 451 | file = self._i_opened_the_file |
| 452 | if file: |
| 453 | self._i_opened_the_file = None |
| 454 | file.close() |
| 455 | |
| 456 | # |
| 457 | # Internal methods. |
| 458 | # |
| 459 | |
| 460 | def _ensure_header_written(self, datasize): |
| 461 | if not self._headerwritten: |
| 462 | if not self._nchannels: |
| 463 | raise Error('# channels not specified') |
| 464 | if not self._sampwidth: |
| 465 | raise Error('sample width not specified') |
| 466 | if not self._framerate: |
| 467 | raise Error('sampling rate not specified') |
| 468 | self._write_header(datasize) |
| 469 | |
| 470 | def _write_header(self, initlength): |
| 471 | assert not self._headerwritten |
| 472 | self._file.write(b'RIFF') |
| 473 | if not self._nframes: |
| 474 | self._nframes = initlength // (self._nchannels * self._sampwidth) |
| 475 | self._datalength = self._nframes * self._nchannels * self._sampwidth |
| 476 | try: |
| 477 | self._form_length_pos = self._file.tell() |
| 478 | except (AttributeError, OSError): |
| 479 | self._form_length_pos = None |
| 480 | self._file.write(struct.pack('<L4s4sLHHLLHH4s', |
| 481 | 36 + self._datalength, b'WAVE', b'fmt ', 16, |
| 482 | WAVE_FORMAT_PCM, self._nchannels, self._framerate, |
| 483 | self._nchannels * self._framerate * self._sampwidth, |
| 484 | self._nchannels * self._sampwidth, |
| 485 | self._sampwidth * 8, b'data')) |
| 486 | if self._form_length_pos is not None: |
| 487 | self._data_length_pos = self._file.tell() |
| 488 | self._file.write(struct.pack('<L', self._datalength)) |
| 489 | self._headerwritten = True |
| 490 | |
| 491 | def _patchheader(self): |
| 492 | assert self._headerwritten |
| 493 | if self._datawritten == self._datalength: |
| 494 | return |
| 495 | curpos = self._file.tell() |
| 496 | self._file.seek(self._form_length_pos, 0) |
| 497 | self._file.write(struct.pack('<L', 36 + self._datawritten)) |
| 498 | self._file.seek(self._data_length_pos, 0) |
| 499 | self._file.write(struct.pack('<L', self._datawritten)) |
| 500 | self._file.seek(curpos, 0) |
| 501 | self._datalength = self._datawritten |
| 502 | |
| 503 | def open(f, mode=None): |
| 504 | if mode is None: |
| 505 | if hasattr(f, 'mode'): |
| 506 | mode = f.mode |
| 507 | else: |
| 508 | mode = 'rb' |
| 509 | if mode in ('r', 'rb'): |
| 510 | return Wave_read(f) |
| 511 | elif mode in ('w', 'wb'): |
| 512 | return Wave_write(f) |
| 513 | else: |
| 514 | raise Error("mode must be 'r', 'rb', 'w', or 'wb'") |
| 515 | |
| 516 | def openfp(f, mode=None): |
| 517 | warnings.warn("wave.openfp is deprecated since Python 3.7. " |
| 518 | "Use wave.open instead.", DeprecationWarning, stacklevel=2) |
| 519 | return open(f, mode=mode) |