Python code coverage for Lib/aifc.py

#	count	content
1	n/a	"""Stuff to parse AIFF-C and AIFF files.
2	n/a
3	n/a	Unless explicitly stated otherwise, the description below is true
4	n/a	both for AIFF-C files and AIFF files.
5	n/a
6	n/a	An AIFF-C file has the following structure.
7	n/a
8	n/a	+-----------------+
9	n/a	\| FORM \|
10	n/a	+-----------------+
11	n/a	\| <size> \|
12	n/a	+----+------------+
13	n/a	\| \| AIFC \|
14	n/a	\| +------------+
15	n/a	\| \| <chunks> \|
16	n/a	\| \| . \|
17	n/a	\| \| . \|
18	n/a	\| \| . \|
19	n/a	+----+------------+
20	n/a
21	n/a	An AIFF file has the string "AIFF" instead of "AIFC".
22	n/a
23	n/a	A chunk consists of an identifier (4 bytes) followed by a size (4 bytes,
24	n/a	big endian order), followed by the data. The size field does not include
25	n/a	the size of the 8 byte header.
26	n/a
27	n/a	The following chunk types are recognized.
28	n/a
29	n/a	FVER
30	n/a	<version number of AIFF-C defining document> (AIFF-C only).
31	n/a	MARK
32	n/a	<# of markers> (2 bytes)
33	n/a	list of markers:
34	n/a	<marker ID> (2 bytes, must be > 0)
35	n/a	<position> (4 bytes)
36	n/a	<marker name> ("pstring")
37	n/a	COMM
38	n/a	<# of channels> (2 bytes)
39	n/a	<# of sound frames> (4 bytes)
40	n/a	<size of the samples> (2 bytes)
41	n/a	<sampling frequency> (10 bytes, IEEE 80-bit extended
42	n/a	floating point)
43	n/a	in AIFF-C files only:
44	n/a	<compression type> (4 bytes)
45	n/a	<human-readable version of compression type> ("pstring")
46	n/a	SSND
47	n/a	<offset> (4 bytes, not used by this program)
48	n/a	<blocksize> (4 bytes, not used by this program)
49	n/a	<sound data>
50	n/a
51	n/a	A pstring consists of 1 byte length, a string of characters, and 0 or 1
52	n/a	byte pad to make the total length even.
53	n/a
54	n/a	Usage.
55	n/a
56	n/a	Reading AIFF files:
57	n/a	f = aifc.open(file, 'r')
58	n/a	where file is either the name of a file or an open file pointer.
59	n/a	The open file pointer must have methods read(), seek(), and close().
60	n/a	In some types of audio files, if the setpos() method is not used,
61	n/a	the seek() method is not necessary.
62	n/a
63	n/a	This returns an instance of a class with the following public methods:
64	n/a	getnchannels() -- returns number of audio channels (1 for
65	n/a	mono, 2 for stereo)
66	n/a	getsampwidth() -- returns sample width in bytes
67	n/a	getframerate() -- returns sampling frequency
68	n/a	getnframes() -- returns number of audio frames
69	n/a	getcomptype() -- returns compression type ('NONE' for AIFF files)
70	n/a	getcompname() -- returns human-readable version of
71	n/a	compression type ('not compressed' for AIFF files)
72	n/a	getparams() -- returns a namedtuple consisting of all of the
73	n/a	above in the above order
74	n/a	getmarkers() -- get the list of marks in the audio file or None
75	n/a	if there are no marks
76	n/a	getmark(id) -- get mark with the specified id (raises an error
77	n/a	if the mark does not exist)
78	n/a	readframes(n) -- returns at most n frames of audio
79	n/a	rewind() -- rewind to the beginning of the audio stream
80	n/a	setpos(pos) -- seek to the specified position
81	n/a	tell() -- return the current position
82	n/a	close() -- close the instance (make it unusable)
83	n/a	The position returned by tell(), the position given to setpos() and
84	n/a	the position of marks are all compatible and have nothing to do with
85	n/a	the actual position in the file.
86	n/a	The close() method is called automatically when the class instance
87	n/a	is destroyed.
88	n/a
89	n/a	Writing AIFF files:
90	n/a	f = aifc.open(file, 'w')
91	n/a	where file is either the name of a file or an open file pointer.
92	n/a	The open file pointer must have methods write(), tell(), seek(), and
93	n/a	close().
94	n/a
95	n/a	This returns an instance of a class with the following public methods:
96	n/a	aiff() -- create an AIFF file (AIFF-C default)
97	n/a	aifc() -- create an AIFF-C file
98	n/a	setnchannels(n) -- set the number of channels
99	n/a	setsampwidth(n) -- set the sample width
100	n/a	setframerate(n) -- set the frame rate
101	n/a	setnframes(n) -- set the number of frames
102	n/a	setcomptype(type, name)
103	n/a	-- set the compression type and the
104	n/a	human-readable compression type
105	n/a	setparams(tuple)
106	n/a	-- set all parameters at once
107	n/a	setmark(id, pos, name)
108	n/a	-- add specified mark to the list of marks
109	n/a	tell() -- return current position in output file (useful
110	n/a	in combination with setmark())
111	n/a	writeframesraw(data)
112	n/a	-- write audio frames without pathing up the
113	n/a	file header
114	n/a	writeframes(data)
115	n/a	-- write audio frames and patch up the file header
116	n/a	close() -- patch up the file header and close the
117	n/a	output file
118	n/a	You should set the parameters before the first writeframesraw or
119	n/a	writeframes. The total number of frames does not need to be set,
120	n/a	but when it is set to the correct value, the header does not have to
121	n/a	be patched up.
122	n/a	It is best to first set all parameters, perhaps possibly the
123	n/a	compression type, and then write audio frames using writeframesraw.
124	n/a	When all frames have been written, either call writeframes(b'') or
125	n/a	close() to patch up the sizes in the header.
126	n/a	Marks can be added anytime. If there are any marks, you must call
127	n/a	close() after all frames have been written.
128	n/a	The close() method is called automatically when the class instance
129	n/a	is destroyed.
130	n/a
131	n/a	When a file is opened with the extension '.aiff', an AIFF file is
132	n/a	written, otherwise an AIFF-C file is written. This default can be
133	n/a	changed by calling aiff() or aifc() before the first writeframes or
134	n/a	writeframesraw.
135	n/a	"""
136	n/a
137	n/a	import struct
138	n/a	import builtins
139	n/a	import warnings
140	n/a
141	n/a	__all__ = ["Error", "open", "openfp"]
142	n/a
143	n/a	class Error(Exception):
144	n/a	pass
145	n/a
146	n/a	_AIFC_version = 0xA2805140 # Version 1 of AIFF-C
147	n/a
148	n/a	def _read_long(file):
149	n/a	try:
150	n/a	return struct.unpack('>l', file.read(4))[0]
151	n/a	except struct.error:
152	n/a	raise EOFError
153	n/a
154	n/a	def _read_ulong(file):
155	n/a	try:
156	n/a	return struct.unpack('>L', file.read(4))[0]
157	n/a	except struct.error:
158	n/a	raise EOFError
159	n/a
160	n/a	def _read_short(file):
161	n/a	try:
162	n/a	return struct.unpack('>h', file.read(2))[0]
163	n/a	except struct.error:
164	n/a	raise EOFError
165	n/a
166	n/a	def _read_ushort(file):
167	n/a	try:
168	n/a	return struct.unpack('>H', file.read(2))[0]
169	n/a	except struct.error:
170	n/a	raise EOFError
171	n/a
172	n/a	def _read_string(file):
173	n/a	length = ord(file.read(1))
174	n/a	if length == 0:
175	n/a	data = b''
176	n/a	else:
177	n/a	data = file.read(length)
178	n/a	if length & 1 == 0:
179	n/a	dummy = file.read(1)
180	n/a	return data
181	n/a
182	n/a	_HUGE_VAL = 1.79769313486231e+308 # See <limits.h>
183	n/a
184	n/a	def _read_float(f): # 10 bytes
185	n/a	expon = _read_short(f) # 2 bytes
186	n/a	sign = 1
187	n/a	if expon < 0:
188	n/a	sign = -1
189	n/a	expon = expon + 0x8000
190	n/a	himant = _read_ulong(f) # 4 bytes
191	n/a	lomant = _read_ulong(f) # 4 bytes
192	n/a	if expon == himant == lomant == 0:
193	n/a	f = 0.0
194	n/a	elif expon == 0x7FFF:
195	n/a	f = _HUGE_VAL
196	n/a	else:
197	n/a	expon = expon - 16383
198	n/a	f = (himant * 0x100000000 + lomant) * pow(2.0, expon - 63)
199	n/a	return sign * f
200	n/a
201	n/a	def _write_short(f, x):
202	n/a	f.write(struct.pack('>h', x))
203	n/a
204	n/a	def _write_ushort(f, x):
205	n/a	f.write(struct.pack('>H', x))
206	n/a
207	n/a	def _write_long(f, x):
208	n/a	f.write(struct.pack('>l', x))
209	n/a
210	n/a	def _write_ulong(f, x):
211	n/a	f.write(struct.pack('>L', x))
212	n/a
213	n/a	def _write_string(f, s):
214	n/a	if len(s) > 255:
215	n/a	raise ValueError("string exceeds maximum pstring length")
216	n/a	f.write(struct.pack('B', len(s)))
217	n/a	f.write(s)
218	n/a	if len(s) & 1 == 0:
219	n/a	f.write(b'\x00')
220	n/a
221	n/a	def _write_float(f, x):
222	n/a	import math
223	n/a	if x < 0:
224	n/a	sign = 0x8000
225	n/a	x = x * -1
226	n/a	else:
227	n/a	sign = 0
228	n/a	if x == 0:
229	n/a	expon = 0
230	n/a	himant = 0
231	n/a	lomant = 0
232	n/a	else:
233	n/a	fmant, expon = math.frexp(x)
234	n/a	if expon > 16384 or fmant >= 1 or fmant != fmant: # Infinity or NaN
235	n/a	expon = sign\|0x7FFF
236	n/a	himant = 0
237	n/a	lomant = 0
238	n/a	else: # Finite
239	n/a	expon = expon + 16382
240	n/a	if expon < 0: # denormalized
241	n/a	fmant = math.ldexp(fmant, expon)
242	n/a	expon = 0
243	n/a	expon = expon \| sign
244	n/a	fmant = math.ldexp(fmant, 32)
245	n/a	fsmant = math.floor(fmant)
246	n/a	himant = int(fsmant)
247	n/a	fmant = math.ldexp(fmant - fsmant, 32)
248	n/a	fsmant = math.floor(fmant)
249	n/a	lomant = int(fsmant)
250	n/a	_write_ushort(f, expon)
251	n/a	_write_ulong(f, himant)
252	n/a	_write_ulong(f, lomant)
253	n/a
254	n/a	from chunk import Chunk
255	n/a	from collections import namedtuple
256	n/a
257	n/a	_aifc_params = namedtuple('_aifc_params',
258	n/a	'nchannels sampwidth framerate nframes comptype compname')
259	n/a
260	n/a	_aifc_params.nchannels.__doc__ = 'Number of audio channels (1 for mono, 2 for stereo)'
261	n/a	_aifc_params.sampwidth.__doc__ = 'Sample width in bytes'
262	n/a	_aifc_params.framerate.__doc__ = 'Sampling frequency'
263	n/a	_aifc_params.nframes.__doc__ = 'Number of audio frames'
264	n/a	_aifc_params.comptype.__doc__ = 'Compression type ("NONE" for AIFF files)'
265	n/a	_aifc_params.compname.__doc__ = ("""\
266	n/a	A human-readable version of the compression type
267	n/a	('not compressed' for AIFF files)""")
268	n/a
269	n/a
270	n/a	class Aifc_read:
271	n/a	# Variables used in this class:
272	n/a	#
273	n/a	# These variables are available to the user though appropriate
274	n/a	# methods of this class:
275	n/a	# _file -- the open file with methods read(), close(), and seek()
276	n/a	# set through the __init__() method
277	n/a	# _nchannels -- the number of audio channels
278	n/a	# available through the getnchannels() method
279	n/a	# _nframes -- the number of audio frames
280	n/a	# available through the getnframes() method
281	n/a	# _sampwidth -- the number of bytes per audio sample
282	n/a	# available through the getsampwidth() method
283	n/a	# _framerate -- the sampling frequency
284	n/a	# available through the getframerate() method
285	n/a	# _comptype -- the AIFF-C compression type ('NONE' if AIFF)
286	n/a	# available through the getcomptype() method
287	n/a	# _compname -- the human-readable AIFF-C compression type
288	n/a	# available through the getcomptype() method
289	n/a	# _markers -- the marks in the audio file
290	n/a	# available through the getmarkers() and getmark()
291	n/a	# methods
292	n/a	# _soundpos -- the position in the audio stream
293	n/a	# available through the tell() method, set through the
294	n/a	# setpos() method
295	n/a	#
296	n/a	# These variables are used internally only:
297	n/a	# _version -- the AIFF-C version number
298	n/a	# _decomp -- the decompressor from builtin module cl
299	n/a	# _comm_chunk_read -- 1 iff the COMM chunk has been read
300	n/a	# _aifc -- 1 iff reading an AIFF-C file
301	n/a	# _ssnd_seek_needed -- 1 iff positioned correctly in audio
302	n/a	# file for readframes()
303	n/a	# _ssnd_chunk -- instantiation of a chunk class for the SSND chunk
304	n/a	# _framesize -- size of one frame in the file
305	n/a
306	n/a	def initfp(self, file):
307	n/a	self._version = 0
308	n/a	self._convert = None
309	n/a	self._markers = []
310	n/a	self._soundpos = 0
311	n/a	self._file = file
312	n/a	chunk = Chunk(file)
313	n/a	if chunk.getname() != b'FORM':
314	n/a	raise Error('file does not start with FORM id')
315	n/a	formdata = chunk.read(4)
316	n/a	if formdata == b'AIFF':
317	n/a	self._aifc = 0
318	n/a	elif formdata == b'AIFC':
319	n/a	self._aifc = 1
320	n/a	else:
321	n/a	raise Error('not an AIFF or AIFF-C file')
322	n/a	self._comm_chunk_read = 0
323	n/a	while 1:
324	n/a	self._ssnd_seek_needed = 1
325	n/a	try:
326	n/a	chunk = Chunk(self._file)
327	n/a	except EOFError:
328	n/a	break
329	n/a	chunkname = chunk.getname()
330	n/a	if chunkname == b'COMM':
331	n/a	self._read_comm_chunk(chunk)
332	n/a	self._comm_chunk_read = 1
333	n/a	elif chunkname == b'SSND':
334	n/a	self._ssnd_chunk = chunk
335	n/a	dummy = chunk.read(8)
336	n/a	self._ssnd_seek_needed = 0
337	n/a	elif chunkname == b'FVER':
338	n/a	self._version = _read_ulong(chunk)
339	n/a	elif chunkname == b'MARK':
340	n/a	self._readmark(chunk)
341	n/a	chunk.skip()
342	n/a	if not self._comm_chunk_read or not self._ssnd_chunk:
343	n/a	raise Error('COMM chunk and/or SSND chunk missing')
344	n/a
345	n/a	def __init__(self, f):
346	n/a	if isinstance(f, str):
347	n/a	f = builtins.open(f, 'rb')
348	n/a	# else, assume it is an open file object already
349	n/a	self.initfp(f)
350	n/a
351	n/a	def __enter__(self):
352	n/a	return self
353	n/a
354	n/a	def __exit__(self, *args):
355	n/a	self.close()
356	n/a
357	n/a	#
358	n/a	# User visible methods.
359	n/a	#
360	n/a	def getfp(self):
361	n/a	return self._file
362	n/a
363	n/a	def rewind(self):
364	n/a	self._ssnd_seek_needed = 1
365	n/a	self._soundpos = 0
366	n/a
367	n/a	def close(self):
368	n/a	file = self._file
369	n/a	if file is not None:
370	n/a	self._file = None
371	n/a	file.close()
372	n/a
373	n/a	def tell(self):
374	n/a	return self._soundpos
375	n/a
376	n/a	def getnchannels(self):
377	n/a	return self._nchannels
378	n/a
379	n/a	def getnframes(self):
380	n/a	return self._nframes
381	n/a
382	n/a	def getsampwidth(self):
383	n/a	return self._sampwidth
384	n/a
385	n/a	def getframerate(self):
386	n/a	return self._framerate
387	n/a
388	n/a	def getcomptype(self):
389	n/a	return self._comptype
390	n/a
391	n/a	def getcompname(self):
392	n/a	return self._compname
393	n/a
394	n/a	## def getversion(self):
395	n/a	## return self._version
396	n/a
397	n/a	def getparams(self):
398	n/a	return _aifc_params(self.getnchannels(), self.getsampwidth(),
399	n/a	self.getframerate(), self.getnframes(),
400	n/a	self.getcomptype(), self.getcompname())
401	n/a
402	n/a	def getmarkers(self):
403	n/a	if len(self._markers) == 0:
404	n/a	return None
405	n/a	return self._markers
406	n/a
407	n/a	def getmark(self, id):
408	n/a	for marker in self._markers:
409	n/a	if id == marker[0]:
410	n/a	return marker
411	n/a	raise Error('marker {0!r} does not exist'.format(id))
412	n/a
413	n/a	def setpos(self, pos):
414	n/a	if pos < 0 or pos > self._nframes:
415	n/a	raise Error('position not in range')
416	n/a	self._soundpos = pos
417	n/a	self._ssnd_seek_needed = 1
418	n/a
419	n/a	def readframes(self, nframes):
420	n/a	if self._ssnd_seek_needed:
421	n/a	self._ssnd_chunk.seek(0)
422	n/a	dummy = self._ssnd_chunk.read(8)
423	n/a	pos = self._soundpos * self._framesize
424	n/a	if pos:
425	n/a	self._ssnd_chunk.seek(pos + 8)
426	n/a	self._ssnd_seek_needed = 0
427	n/a	if nframes == 0:
428	n/a	return b''
429	n/a	data = self._ssnd_chunk.read(nframes * self._framesize)
430	n/a	if self._convert and data:
431	n/a	data = self._convert(data)
432	n/a	self._soundpos = self._soundpos + len(data) // (self._nchannels
433	n/a	* self._sampwidth)
434	n/a	return data
435	n/a
436	n/a	#
437	n/a	# Internal methods.
438	n/a	#
439	n/a
440	n/a	def _alaw2lin(self, data):
441	n/a	import audioop
442	n/a	return audioop.alaw2lin(data, 2)
443	n/a
444	n/a	def _ulaw2lin(self, data):
445	n/a	import audioop
446	n/a	return audioop.ulaw2lin(data, 2)
447	n/a
448	n/a	def _adpcm2lin(self, data):
449	n/a	import audioop
450	n/a	if not hasattr(self, '_adpcmstate'):
451	n/a	# first time
452	n/a	self._adpcmstate = None
453	n/a	data, self._adpcmstate = audioop.adpcm2lin(data, 2, self._adpcmstate)
454	n/a	return data
455	n/a
456	n/a	def _read_comm_chunk(self, chunk):
457	n/a	self._nchannels = _read_short(chunk)
458	n/a	self._nframes = _read_long(chunk)
459	n/a	self._sampwidth = (_read_short(chunk) + 7) // 8
460	n/a	self._framerate = int(_read_float(chunk))
461	n/a	self._framesize = self._nchannels * self._sampwidth
462	n/a	if self._aifc:
463	n/a	#DEBUG: SGI's soundeditor produces a bad size :-(
464	n/a	kludge = 0
465	n/a	if chunk.chunksize == 18:
466	n/a	kludge = 1
467	n/a	warnings.warn('Warning: bad COMM chunk size')
468	n/a	chunk.chunksize = 23
469	n/a	#DEBUG end
470	n/a	self._comptype = chunk.read(4)
471	n/a	#DEBUG start
472	n/a	if kludge:
473	n/a	length = ord(chunk.file.read(1))
474	n/a	if length & 1 == 0:
475	n/a	length = length + 1
476	n/a	chunk.chunksize = chunk.chunksize + length
477	n/a	chunk.file.seek(-1, 1)
478	n/a	#DEBUG end
479	n/a	self._compname = _read_string(chunk)
480	n/a	if self._comptype != b'NONE':
481	n/a	if self._comptype == b'G722':
482	n/a	self._convert = self._adpcm2lin
483	n/a	elif self._comptype in (b'ulaw', b'ULAW'):
484	n/a	self._convert = self._ulaw2lin
485	n/a	elif self._comptype in (b'alaw', b'ALAW'):
486	n/a	self._convert = self._alaw2lin
487	n/a	else:
488	n/a	raise Error('unsupported compression type')
489	n/a	self._sampwidth = 2
490	n/a	else:
491	n/a	self._comptype = b'NONE'
492	n/a	self._compname = b'not compressed'
493	n/a
494	n/a	def _readmark(self, chunk):
495	n/a	nmarkers = _read_short(chunk)
496	n/a	# Some files appear to contain invalid counts.
497	n/a	# Cope with this by testing for EOF.
498	n/a	try:
499	n/a	for i in range(nmarkers):
500	n/a	id = _read_short(chunk)
501	n/a	pos = _read_long(chunk)
502	n/a	name = _read_string(chunk)
503	n/a	if pos or name:
504	n/a	# some files appear to have
505	n/a	# dummy markers consisting of
506	n/a	# a position 0 and name ''
507	n/a	self._markers.append((id, pos, name))
508	n/a	except EOFError:
509	n/a	w = ('Warning: MARK chunk contains only %s marker%s instead of %s' %
510	n/a	(len(self._markers), '' if len(self._markers) == 1 else 's',
511	n/a	nmarkers))
512	n/a	warnings.warn(w)
513	n/a
514	n/a	class Aifc_write:
515	n/a	# Variables used in this class:
516	n/a	#
517	n/a	# These variables are user settable through appropriate methods
518	n/a	# of this class:
519	n/a	# _file -- the open file with methods write(), close(), tell(), seek()
520	n/a	# set through the __init__() method
521	n/a	# _comptype -- the AIFF-C compression type ('NONE' in AIFF)
522	n/a	# set through the setcomptype() or setparams() method
523	n/a	# _compname -- the human-readable AIFF-C compression type
524	n/a	# set through the setcomptype() or setparams() method
525	n/a	# _nchannels -- the number of audio channels
526	n/a	# set through the setnchannels() or setparams() method
527	n/a	# _sampwidth -- the number of bytes per audio sample
528	n/a	# set through the setsampwidth() or setparams() method
529	n/a	# _framerate -- the sampling frequency
530	n/a	# set through the setframerate() or setparams() method
531	n/a	# _nframes -- the number of audio frames written to the header
532	n/a	# set through the setnframes() or setparams() method
533	n/a	# _aifc -- whether we're writing an AIFF-C file or an AIFF file
534	n/a	# set through the aifc() method, reset through the
535	n/a	# aiff() method
536	n/a	#
537	n/a	# These variables are used internally only:
538	n/a	# _version -- the AIFF-C version number
539	n/a	# _comp -- the compressor from builtin module cl
540	n/a	# _nframeswritten -- the number of audio frames actually written
541	n/a	# _datalength -- the size of the audio samples written to the header
542	n/a	# _datawritten -- the size of the audio samples actually written
543	n/a
544	n/a	def __init__(self, f):
545	n/a	if isinstance(f, str):
546	n/a	filename = f
547	n/a	f = builtins.open(f, 'wb')
548	n/a	else:
549	n/a	# else, assume it is an open file object already
550	n/a	filename = '???'
551	n/a	self.initfp(f)
552	n/a	if filename[-5:] == '.aiff':
553	n/a	self._aifc = 0
554	n/a	else:
555	n/a	self._aifc = 1
556	n/a
557	n/a	def initfp(self, file):
558	n/a	self._file = file
559	n/a	self._version = _AIFC_version
560	n/a	self._comptype = b'NONE'
561	n/a	self._compname = b'not compressed'
562	n/a	self._convert = None
563	n/a	self._nchannels = 0
564	n/a	self._sampwidth = 0
565	n/a	self._framerate = 0
566	n/a	self._nframes = 0
567	n/a	self._nframeswritten = 0
568	n/a	self._datawritten = 0
569	n/a	self._datalength = 0
570	n/a	self._markers = []
571	n/a	self._marklength = 0
572	n/a	self._aifc = 1 # AIFF-C is default
573	n/a
574	n/a	def __del__(self):
575	n/a	self.close()
576	n/a
577	n/a	def __enter__(self):
578	n/a	return self
579	n/a
580	n/a	def __exit__(self, *args):
581	n/a	self.close()
582	n/a
583	n/a	#
584	n/a	# User visible methods.
585	n/a	#
586	n/a	def aiff(self):
587	n/a	if self._nframeswritten:
588	n/a	raise Error('cannot change parameters after starting to write')
589	n/a	self._aifc = 0
590	n/a
591	n/a	def aifc(self):
592	n/a	if self._nframeswritten:
593	n/a	raise Error('cannot change parameters after starting to write')
594	n/a	self._aifc = 1
595	n/a
596	n/a	def setnchannels(self, nchannels):
597	n/a	if self._nframeswritten:
598	n/a	raise Error('cannot change parameters after starting to write')
599	n/a	if nchannels < 1:
600	n/a	raise Error('bad # of channels')
601	n/a	self._nchannels = nchannels
602	n/a
603	n/a	def getnchannels(self):
604	n/a	if not self._nchannels:
605	n/a	raise Error('number of channels not set')
606	n/a	return self._nchannels
607	n/a
608	n/a	def setsampwidth(self, sampwidth):
609	n/a	if self._nframeswritten:
610	n/a	raise Error('cannot change parameters after starting to write')
611	n/a	if sampwidth < 1 or sampwidth > 4:
612	n/a	raise Error('bad sample width')
613	n/a	self._sampwidth = sampwidth
614	n/a
615	n/a	def getsampwidth(self):
616	n/a	if not self._sampwidth:
617	n/a	raise Error('sample width not set')
618	n/a	return self._sampwidth
619	n/a
620	n/a	def setframerate(self, framerate):
621	n/a	if self._nframeswritten:
622	n/a	raise Error('cannot change parameters after starting to write')
623	n/a	if framerate <= 0:
624	n/a	raise Error('bad frame rate')
625	n/a	self._framerate = framerate
626	n/a
627	n/a	def getframerate(self):
628	n/a	if not self._framerate:
629	n/a	raise Error('frame rate not set')
630	n/a	return self._framerate
631	n/a
632	n/a	def setnframes(self, nframes):
633	n/a	if self._nframeswritten:
634	n/a	raise Error('cannot change parameters after starting to write')
635	n/a	self._nframes = nframes
636	n/a
637	n/a	def getnframes(self):
638	n/a	return self._nframeswritten
639	n/a
640	n/a	def setcomptype(self, comptype, compname):
641	n/a	if self._nframeswritten:
642	n/a	raise Error('cannot change parameters after starting to write')
643	n/a	if comptype not in (b'NONE', b'ulaw', b'ULAW',
644	n/a	b'alaw', b'ALAW', b'G722'):
645	n/a	raise Error('unsupported compression type')
646	n/a	self._comptype = comptype
647	n/a	self._compname = compname
648	n/a
649	n/a	def getcomptype(self):
650	n/a	return self._comptype
651	n/a
652	n/a	def getcompname(self):
653	n/a	return self._compname
654	n/a
655	n/a	## def setversion(self, version):
656	n/a	## if self._nframeswritten:
657	n/a	## raise Error, 'cannot change parameters after starting to write'
658	n/a	## self._version = version
659	n/a
660	n/a	def setparams(self, params):
661	n/a	nchannels, sampwidth, framerate, nframes, comptype, compname = params
662	n/a	if self._nframeswritten:
663	n/a	raise Error('cannot change parameters after starting to write')
664	n/a	if comptype not in (b'NONE', b'ulaw', b'ULAW',
665	n/a	b'alaw', b'ALAW', b'G722'):
666	n/a	raise Error('unsupported compression type')
667	n/a	self.setnchannels(nchannels)
668	n/a	self.setsampwidth(sampwidth)
669	n/a	self.setframerate(framerate)
670	n/a	self.setnframes(nframes)
671	n/a	self.setcomptype(comptype, compname)
672	n/a
673	n/a	def getparams(self):
674	n/a	if not self._nchannels or not self._sampwidth or not self._framerate:
675	n/a	raise Error('not all parameters set')
676	n/a	return _aifc_params(self._nchannels, self._sampwidth, self._framerate,
677	n/a	self._nframes, self._comptype, self._compname)
678	n/a
679	n/a	def setmark(self, id, pos, name):
680	n/a	if id <= 0:
681	n/a	raise Error('marker ID must be > 0')
682	n/a	if pos < 0:
683	n/a	raise Error('marker position must be >= 0')
684	n/a	if not isinstance(name, bytes):
685	n/a	raise Error('marker name must be bytes')
686	n/a	for i in range(len(self._markers)):
687	n/a	if id == self._markers[i][0]:
688	n/a	self._markers[i] = id, pos, name
689	n/a	return
690	n/a	self._markers.append((id, pos, name))
691	n/a
692	n/a	def getmark(self, id):
693	n/a	for marker in self._markers:
694	n/a	if id == marker[0]:
695	n/a	return marker
696	n/a	raise Error('marker {0!r} does not exist'.format(id))
697	n/a
698	n/a	def getmarkers(self):
699	n/a	if len(self._markers) == 0:
700	n/a	return None
701	n/a	return self._markers
702	n/a
703	n/a	def tell(self):
704	n/a	return self._nframeswritten
705	n/a
706	n/a	def writeframesraw(self, data):
707	n/a	if not isinstance(data, (bytes, bytearray)):
708	n/a	data = memoryview(data).cast('B')
709	n/a	self._ensure_header_written(len(data))
710	n/a	nframes = len(data) // (self._sampwidth * self._nchannels)
711	n/a	if self._convert:
712	n/a	data = self._convert(data)
713	n/a	self._file.write(data)
714	n/a	self._nframeswritten = self._nframeswritten + nframes
715	n/a	self._datawritten = self._datawritten + len(data)
716	n/a
717	n/a	def writeframes(self, data):
718	n/a	self.writeframesraw(data)
719	n/a	if self._nframeswritten != self._nframes or \
720	n/a	self._datalength != self._datawritten:
721	n/a	self._patchheader()
722	n/a
723	n/a	def close(self):
724	n/a	if self._file is None:
725	n/a	return
726	n/a	try:
727	n/a	self._ensure_header_written(0)
728	n/a	if self._datawritten & 1:
729	n/a	# quick pad to even size
730	n/a	self._file.write(b'\x00')
731	n/a	self._datawritten = self._datawritten + 1
732	n/a	self._writemarkers()
733	n/a	if self._nframeswritten != self._nframes or \
734	n/a	self._datalength != self._datawritten or \
735	n/a	self._marklength:
736	n/a	self._patchheader()
737	n/a	finally:
738	n/a	# Prevent ref cycles
739	n/a	self._convert = None
740	n/a	f = self._file
741	n/a	self._file = None
742	n/a	f.close()
743	n/a
744	n/a	#
745	n/a	# Internal methods.
746	n/a	#
747	n/a
748	n/a	def _lin2alaw(self, data):
749	n/a	import audioop
750	n/a	return audioop.lin2alaw(data, 2)
751	n/a
752	n/a	def _lin2ulaw(self, data):
753	n/a	import audioop
754	n/a	return audioop.lin2ulaw(data, 2)
755	n/a
756	n/a	def _lin2adpcm(self, data):
757	n/a	import audioop
758	n/a	if not hasattr(self, '_adpcmstate'):
759	n/a	self._adpcmstate = None
760	n/a	data, self._adpcmstate = audioop.lin2adpcm(data, 2, self._adpcmstate)
761	n/a	return data
762	n/a
763	n/a	def _ensure_header_written(self, datasize):
764	n/a	if not self._nframeswritten:
765	n/a	if self._comptype in (b'ULAW', b'ulaw', b'ALAW', b'alaw', b'G722'):
766	n/a	if not self._sampwidth:
767	n/a	self._sampwidth = 2
768	n/a	if self._sampwidth != 2:
769	n/a	raise Error('sample width must be 2 when compressing '
770	n/a	'with ulaw/ULAW, alaw/ALAW or G7.22 (ADPCM)')
771	n/a	if not self._nchannels:
772	n/a	raise Error('# channels not specified')
773	n/a	if not self._sampwidth:
774	n/a	raise Error('sample width not specified')
775	n/a	if not self._framerate:
776	n/a	raise Error('sampling rate not specified')
777	n/a	self._write_header(datasize)
778	n/a
779	n/a	def _init_compression(self):
780	n/a	if self._comptype == b'G722':
781	n/a	self._convert = self._lin2adpcm
782	n/a	elif self._comptype in (b'ulaw', b'ULAW'):
783	n/a	self._convert = self._lin2ulaw
784	n/a	elif self._comptype in (b'alaw', b'ALAW'):
785	n/a	self._convert = self._lin2alaw
786	n/a
787	n/a	def _write_header(self, initlength):
788	n/a	if self._aifc and self._comptype != b'NONE':
789	n/a	self._init_compression()
790	n/a	self._file.write(b'FORM')
791	n/a	if not self._nframes:
792	n/a	self._nframes = initlength // (self._nchannels * self._sampwidth)
793	n/a	self._datalength = self._nframes * self._nchannels * self._sampwidth
794	n/a	if self._datalength & 1:
795	n/a	self._datalength = self._datalength + 1
796	n/a	if self._aifc:
797	n/a	if self._comptype in (b'ulaw', b'ULAW', b'alaw', b'ALAW'):
798	n/a	self._datalength = self._datalength // 2
799	n/a	if self._datalength & 1:
800	n/a	self._datalength = self._datalength + 1
801	n/a	elif self._comptype == b'G722':
802	n/a	self._datalength = (self._datalength + 3) // 4
803	n/a	if self._datalength & 1:
804	n/a	self._datalength = self._datalength + 1
805	n/a	try:
806	n/a	self._form_length_pos = self._file.tell()
807	n/a	except (AttributeError, OSError):
808	n/a	self._form_length_pos = None
809	n/a	commlength = self._write_form_length(self._datalength)
810	n/a	if self._aifc:
811	n/a	self._file.write(b'AIFC')
812	n/a	self._file.write(b'FVER')
813	n/a	_write_ulong(self._file, 4)
814	n/a	_write_ulong(self._file, self._version)
815	n/a	else:
816	n/a	self._file.write(b'AIFF')
817	n/a	self._file.write(b'COMM')
818	n/a	_write_ulong(self._file, commlength)
819	n/a	_write_short(self._file, self._nchannels)
820	n/a	if self._form_length_pos is not None:
821	n/a	self._nframes_pos = self._file.tell()
822	n/a	_write_ulong(self._file, self._nframes)
823	n/a	if self._comptype in (b'ULAW', b'ulaw', b'ALAW', b'alaw', b'G722'):
824	n/a	_write_short(self._file, 8)
825	n/a	else:
826	n/a	_write_short(self._file, self._sampwidth * 8)
827	n/a	_write_float(self._file, self._framerate)
828	n/a	if self._aifc:
829	n/a	self._file.write(self._comptype)
830	n/a	_write_string(self._file, self._compname)
831	n/a	self._file.write(b'SSND')
832	n/a	if self._form_length_pos is not None:
833	n/a	self._ssnd_length_pos = self._file.tell()
834	n/a	_write_ulong(self._file, self._datalength + 8)
835	n/a	_write_ulong(self._file, 0)
836	n/a	_write_ulong(self._file, 0)
837	n/a
838	n/a	def _write_form_length(self, datalength):
839	n/a	if self._aifc:
840	n/a	commlength = 18 + 5 + len(self._compname)
841	n/a	if commlength & 1:
842	n/a	commlength = commlength + 1
843	n/a	verslength = 12
844	n/a	else:
845	n/a	commlength = 18
846	n/a	verslength = 0
847	n/a	_write_ulong(self._file, 4 + verslength + self._marklength + \
848	n/a	8 + commlength + 16 + datalength)
849	n/a	return commlength
850	n/a
851	n/a	def _patchheader(self):
852	n/a	curpos = self._file.tell()
853	n/a	if self._datawritten & 1:
854	n/a	datalength = self._datawritten + 1
855	n/a	self._file.write(b'\x00')
856	n/a	else:
857	n/a	datalength = self._datawritten
858	n/a	if datalength == self._datalength and \
859	n/a	self._nframes == self._nframeswritten and \
860	n/a	self._marklength == 0:
861	n/a	self._file.seek(curpos, 0)
862	n/a	return
863	n/a	self._file.seek(self._form_length_pos, 0)
864	n/a	dummy = self._write_form_length(datalength)
865	n/a	self._file.seek(self._nframes_pos, 0)
866	n/a	_write_ulong(self._file, self._nframeswritten)
867	n/a	self._file.seek(self._ssnd_length_pos, 0)
868	n/a	_write_ulong(self._file, datalength + 8)
869	n/a	self._file.seek(curpos, 0)
870	n/a	self._nframes = self._nframeswritten
871	n/a	self._datalength = datalength
872	n/a
873	n/a	def _writemarkers(self):
874	n/a	if len(self._markers) == 0:
875	n/a	return
876	n/a	self._file.write(b'MARK')
877	n/a	length = 2
878	n/a	for marker in self._markers:
879	n/a	id, pos, name = marker
880	n/a	length = length + len(name) + 1 + 6
881	n/a	if len(name) & 1 == 0:
882	n/a	length = length + 1
883	n/a	_write_ulong(self._file, length)
884	n/a	self._marklength = length + 8
885	n/a	_write_short(self._file, len(self._markers))
886	n/a	for marker in self._markers:
887	n/a	id, pos, name = marker
888	n/a	_write_short(self._file, id)
889	n/a	_write_ulong(self._file, pos)
890	n/a	_write_string(self._file, name)
891	n/a
892	n/a	def open(f, mode=None):
893	n/a	if mode is None:
894	n/a	if hasattr(f, 'mode'):
895	n/a	mode = f.mode
896	n/a	else:
897	n/a	mode = 'rb'
898	n/a	if mode in ('r', 'rb'):
899	n/a	return Aifc_read(f)
900	n/a	elif mode in ('w', 'wb'):
901	n/a	return Aifc_write(f)
902	n/a	else:
903	n/a	raise Error("mode must be 'r', 'rb', 'w', or 'wb'")
904	n/a
905	n/a	openfp = open # B/W compatibility
906	n/a
907	n/a	if __name__ == '__main__':
908	n/a	import sys
909	n/a	if not sys.argv[1:]:
910	n/a	sys.argv.append('/usr/demos/data/audio/bach.aiff')
911	n/a	fn = sys.argv[1]
912	n/a	with open(fn, 'r') as f:
913	n/a	print("Reading", fn)
914	n/a	print("nchannels =", f.getnchannels())
915	n/a	print("nframes =", f.getnframes())
916	n/a	print("sampwidth =", f.getsampwidth())
917	n/a	print("framerate =", f.getframerate())
918	n/a	print("comptype =", f.getcomptype())
919	n/a	print("compname =", f.getcompname())
920	n/a	if sys.argv[2:]:
921	n/a	gn = sys.argv[2]
922	n/a	print("Writing", gn)
923	n/a	with open(gn, 'w') as g:
924	n/a	g.setparams(f.getparams())
925	n/a	while 1:
926	n/a	data = f.readframes(1024)
927	n/a	if not data:
928	n/a	break
929	n/a	g.writeframes(data)
930	n/a	print("Done.")