Python code coverage for Modules/audioop.c

#	count	content
1	n/a
2	n/a	/* audioopmodule - Module to detect peak values in arrays */
3	n/a
4	n/a	#define PY_SSIZE_T_CLEAN
5	n/a
6	n/a	#include "Python.h"
7	n/a
8	n/a	#if defined(__CHAR_UNSIGNED__)
9	n/a	#if defined(signed)
10	n/a	/* This module currently does not work on systems where only unsigned
11	n/a	characters are available. Take it out of Setup. Sorry. */
12	n/a	#endif
13	n/a	#endif
14	n/a
15	n/a	static const int maxvals[] = {0, 0x7F, 0x7FFF, 0x7FFFFF, 0x7FFFFFFF};
16	n/a	/* -1 trick is needed on Windows to support -0x80000000 without a warning */
17	n/a	static const int minvals[] = {0, -0x80, -0x8000, -0x800000, -0x7FFFFFFF-1};
18	n/a	static const unsigned int masks[] = {0, 0xFF, 0xFFFF, 0xFFFFFF, 0xFFFFFFFF};
19	n/a
20	n/a	static int
21	n/a	fbound(double val, double minval, double maxval)
22	n/a	{
23	n/a	if (val > maxval)
24	n/a	val = maxval;
25	n/a	else if (val < minval + 1)
26	n/a	val = minval;
27	n/a	return (int)val;
28	n/a	}
29	n/a
30	n/a
31	n/a	/* Code shamelessly stolen from sox, 12.17.7, g711.c
32	n/a	** (c) Craig Reese, Joe Campbell and Jeff Poskanzer 1989 */
33	n/a
34	n/a	/* From g711.c:
35	n/a	*
36	n/a	* December 30, 1994:
37	n/a	* Functions linear2alaw, linear2ulaw have been updated to correctly
38	n/a	* convert unquantized 16 bit values.
39	n/a	* Tables for direct u- to A-law and A- to u-law conversions have been
40	n/a	* corrected.
41	n/a	* Borge Lindberg, Center for PersonKommunikation, Aalborg University.
42	n/a	* bli@cpk.auc.dk
43	n/a	*
44	n/a	*/
45	n/a	#define BIAS 0x84 /* define the add-in bias for 16 bit samples */
46	n/a	#define CLIP 32635
47	n/a	#define SIGN_BIT (0x80) /* Sign bit for an A-law byte. */
48	n/a	#define QUANT_MASK (0xf) /* Quantization field mask. */
49	n/a	#define SEG_SHIFT (4) /* Left shift for segment number. */
50	n/a	#define SEG_MASK (0x70) /* Segment field mask. */
51	n/a
52	n/a	static const int16_t seg_aend[8] = {
53	n/a	0x1F, 0x3F, 0x7F, 0xFF, 0x1FF, 0x3FF, 0x7FF, 0xFFF
54	n/a	};
55	n/a	static const int16_t seg_uend[8] = {
56	n/a	0x3F, 0x7F, 0xFF, 0x1FF, 0x3FF, 0x7FF, 0xFFF, 0x1FFF
57	n/a	};
58	n/a
59	n/a	static int16_t
60	n/a	search(int16_t val, const int16_t *table, int size)
61	n/a	{
62	n/a	int i;
63	n/a
64	n/a	for (i = 0; i < size; i++) {
65	n/a	if (val <= *table++)
66	n/a	return (i);
67	n/a	}
68	n/a	return (size);
69	n/a	}
70	n/a	#define st_ulaw2linear16(uc) (_st_ulaw2linear16[uc])
71	n/a	#define st_alaw2linear16(uc) (_st_alaw2linear16[uc])
72	n/a
73	n/a	static const int16_t _st_ulaw2linear16[256] = {
74	n/a	-32124, -31100, -30076, -29052, -28028, -27004, -25980,
75	n/a	-24956, -23932, -22908, -21884, -20860, -19836, -18812,
76	n/a	-17788, -16764, -15996, -15484, -14972, -14460, -13948,
77	n/a	-13436, -12924, -12412, -11900, -11388, -10876, -10364,
78	n/a	-9852, -9340, -8828, -8316, -7932, -7676, -7420,
79	n/a	-7164, -6908, -6652, -6396, -6140, -5884, -5628,
80	n/a	-5372, -5116, -4860, -4604, -4348, -4092, -3900,
81	n/a	-3772, -3644, -3516, -3388, -3260, -3132, -3004,
82	n/a	-2876, -2748, -2620, -2492, -2364, -2236, -2108,
83	n/a	-1980, -1884, -1820, -1756, -1692, -1628, -1564,
84	n/a	-1500, -1436, -1372, -1308, -1244, -1180, -1116,
85	n/a	-1052, -988, -924, -876, -844, -812, -780,
86	n/a	-748, -716, -684, -652, -620, -588, -556,
87	n/a	-524, -492, -460, -428, -396, -372, -356,
88	n/a	-340, -324, -308, -292, -276, -260, -244,
89	n/a	-228, -212, -196, -180, -164, -148, -132,
90	n/a	-120, -112, -104, -96, -88, -80, -72,
91	n/a	-64, -56, -48, -40, -32, -24, -16,
92	n/a	-8, 0, 32124, 31100, 30076, 29052, 28028,
93	n/a	27004, 25980, 24956, 23932, 22908, 21884, 20860,
94	n/a	19836, 18812, 17788, 16764, 15996, 15484, 14972,
95	n/a	14460, 13948, 13436, 12924, 12412, 11900, 11388,
96	n/a	10876, 10364, 9852, 9340, 8828, 8316, 7932,
97	n/a	7676, 7420, 7164, 6908, 6652, 6396, 6140,
98	n/a	5884, 5628, 5372, 5116, 4860, 4604, 4348,
99	n/a	4092, 3900, 3772, 3644, 3516, 3388, 3260,
100	n/a	3132, 3004, 2876, 2748, 2620, 2492, 2364,
101	n/a	2236, 2108, 1980, 1884, 1820, 1756, 1692,
102	n/a	1628, 1564, 1500, 1436, 1372, 1308, 1244,
103	n/a	1180, 1116, 1052, 988, 924, 876, 844,
104	n/a	812, 780, 748, 716, 684, 652, 620,
105	n/a	588, 556, 524, 492, 460, 428, 396,
106	n/a	372, 356, 340, 324, 308, 292, 276,
107	n/a	260, 244, 228, 212, 196, 180, 164,
108	n/a	148, 132, 120, 112, 104, 96, 88,
109	n/a	80, 72, 64, 56, 48, 40, 32,
110	n/a	24, 16, 8, 0
111	n/a	};
112	n/a
113	n/a	/*
114	n/a	* linear2ulaw() accepts a 14-bit signed integer and encodes it as u-law data
115	n/a	* stored in an unsigned char. This function should only be called with
116	n/a	* the data shifted such that it only contains information in the lower
117	n/a	* 14-bits.
118	n/a	*
119	n/a	* In order to simplify the encoding process, the original linear magnitude
120	n/a	* is biased by adding 33 which shifts the encoding range from (0 - 8158) to
121	n/a	* (33 - 8191). The result can be seen in the following encoding table:
122	n/a	*
123	n/a	* Biased Linear Input Code Compressed Code
124	n/a	* ------------------------ ---------------
125	n/a	* 00000001wxyza 000wxyz
126	n/a	* 0000001wxyzab 001wxyz
127	n/a	* 000001wxyzabc 010wxyz
128	n/a	* 00001wxyzabcd 011wxyz
129	n/a	* 0001wxyzabcde 100wxyz
130	n/a	* 001wxyzabcdef 101wxyz
131	n/a	* 01wxyzabcdefg 110wxyz
132	n/a	* 1wxyzabcdefgh 111wxyz
133	n/a	*
134	n/a	* Each biased linear code has a leading 1 which identifies the segment
135	n/a	* number. The value of the segment number is equal to 7 minus the number
136	n/a	* of leading 0's. The quantization interval is directly available as the
137	n/a	* four bits wxyz. * The trailing bits (a - h) are ignored.
138	n/a	*
139	n/a	* Ordinarily the complement of the resulting code word is used for
140	n/a	* transmission, and so the code word is complemented before it is returned.
141	n/a	*
142	n/a	* For further information see John C. Bellamy's Digital Telephony, 1982,
143	n/a	* John Wiley & Sons, pps 98-111 and 472-476.
144	n/a	*/
145	n/a	static unsigned char
146	n/a	st_14linear2ulaw(int16_t pcm_val) /* 2's complement (14-bit range) */
147	n/a	{
148	n/a	int16_t mask;
149	n/a	int16_t seg;
150	n/a	unsigned char uval;
151	n/a
152	n/a	/* u-law inverts all bits */
153	n/a	/* Get the sign and the magnitude of the value. */
154	n/a	if (pcm_val < 0) {
155	n/a	pcm_val = -pcm_val;
156	n/a	mask = 0x7F;
157	n/a	} else {
158	n/a	mask = 0xFF;
159	n/a	}
160	n/a	if ( pcm_val > CLIP ) pcm_val = CLIP; /* clip the magnitude */
161	n/a	pcm_val += (BIAS >> 2);
162	n/a
163	n/a	/* Convert the scaled magnitude to segment number. */
164	n/a	seg = search(pcm_val, seg_uend, 8);
165	n/a
166	n/a	/*
167	n/a	* Combine the sign, segment, quantization bits;
168	n/a	* and complement the code word.
169	n/a	*/
170	n/a	if (seg >= 8) /* out of range, return maximum value. */
171	n/a	return (unsigned char) (0x7F ^ mask);
172	n/a	else {
173	n/a	uval = (unsigned char) (seg << 4) \| ((pcm_val >> (seg + 1)) & 0xF);
174	n/a	return (uval ^ mask);
175	n/a	}
176	n/a
177	n/a	}
178	n/a
179	n/a	static const int16_t _st_alaw2linear16[256] = {
180	n/a	-5504, -5248, -6016, -5760, -4480, -4224, -4992,
181	n/a	-4736, -7552, -7296, -8064, -7808, -6528, -6272,
182	n/a	-7040, -6784, -2752, -2624, -3008, -2880, -2240,
183	n/a	-2112, -2496, -2368, -3776, -3648, -4032, -3904,
184	n/a	-3264, -3136, -3520, -3392, -22016, -20992, -24064,
185	n/a	-23040, -17920, -16896, -19968, -18944, -30208, -29184,
186	n/a	-32256, -31232, -26112, -25088, -28160, -27136, -11008,
187	n/a	-10496, -12032, -11520, -8960, -8448, -9984, -9472,
188	n/a	-15104, -14592, -16128, -15616, -13056, -12544, -14080,
189	n/a	-13568, -344, -328, -376, -360, -280, -264,
190	n/a	-312, -296, -472, -456, -504, -488, -408,
191	n/a	-392, -440, -424, -88, -72, -120, -104,
192	n/a	-24, -8, -56, -40, -216, -200, -248,
193	n/a	-232, -152, -136, -184, -168, -1376, -1312,
194	n/a	-1504, -1440, -1120, -1056, -1248, -1184, -1888,
195	n/a	-1824, -2016, -1952, -1632, -1568, -1760, -1696,
196	n/a	-688, -656, -752, -720, -560, -528, -624,
197	n/a	-592, -944, -912, -1008, -976, -816, -784,
198	n/a	-880, -848, 5504, 5248, 6016, 5760, 4480,
199	n/a	4224, 4992, 4736, 7552, 7296, 8064, 7808,
200	n/a	6528, 6272, 7040, 6784, 2752, 2624, 3008,
201	n/a	2880, 2240, 2112, 2496, 2368, 3776, 3648,
202	n/a	4032, 3904, 3264, 3136, 3520, 3392, 22016,
203	n/a	20992, 24064, 23040, 17920, 16896, 19968, 18944,
204	n/a	30208, 29184, 32256, 31232, 26112, 25088, 28160,
205	n/a	27136, 11008, 10496, 12032, 11520, 8960, 8448,
206	n/a	9984, 9472, 15104, 14592, 16128, 15616, 13056,
207	n/a	12544, 14080, 13568, 344, 328, 376, 360,
208	n/a	280, 264, 312, 296, 472, 456, 504,
209	n/a	488, 408, 392, 440, 424, 88, 72,
210	n/a	120, 104, 24, 8, 56, 40, 216,
211	n/a	200, 248, 232, 152, 136, 184, 168,
212	n/a	1376, 1312, 1504, 1440, 1120, 1056, 1248,
213	n/a	1184, 1888, 1824, 2016, 1952, 1632, 1568,
214	n/a	1760, 1696, 688, 656, 752, 720, 560,
215	n/a	528, 624, 592, 944, 912, 1008, 976,
216	n/a	816, 784, 880, 848
217	n/a	};
218	n/a
219	n/a	/*
220	n/a	* linear2alaw() accepts a 13-bit signed integer and encodes it as A-law data
221	n/a	* stored in an unsigned char. This function should only be called with
222	n/a	* the data shifted such that it only contains information in the lower
223	n/a	* 13-bits.
224	n/a	*
225	n/a	* Linear Input Code Compressed Code
226	n/a	* ------------------------ ---------------
227	n/a	* 0000000wxyza 000wxyz
228	n/a	* 0000001wxyza 001wxyz
229	n/a	* 000001wxyzab 010wxyz
230	n/a	* 00001wxyzabc 011wxyz
231	n/a	* 0001wxyzabcd 100wxyz
232	n/a	* 001wxyzabcde 101wxyz
233	n/a	* 01wxyzabcdef 110wxyz
234	n/a	* 1wxyzabcdefg 111wxyz
235	n/a	*
236	n/a	* For further information see John C. Bellamy's Digital Telephony, 1982,
237	n/a	* John Wiley & Sons, pps 98-111 and 472-476.
238	n/a	*/
239	n/a	static unsigned char
240	n/a	st_linear2alaw(int16_t pcm_val) /* 2's complement (13-bit range) */
241	n/a	{
242	n/a	int16_t mask;
243	n/a	int16_t seg;
244	n/a	unsigned char aval;
245	n/a
246	n/a	/* A-law using even bit inversion */
247	n/a	if (pcm_val >= 0) {
248	n/a	mask = 0xD5; /* sign (7th) bit = 1 */
249	n/a	} else {
250	n/a	mask = 0x55; /* sign bit = 0 */
251	n/a	pcm_val = -pcm_val - 1;
252	n/a	}
253	n/a
254	n/a	/* Convert the scaled magnitude to segment number. */
255	n/a	seg = search(pcm_val, seg_aend, 8);
256	n/a
257	n/a	/* Combine the sign, segment, and quantization bits. */
258	n/a
259	n/a	if (seg >= 8) /* out of range, return maximum value. */
260	n/a	return (unsigned char) (0x7F ^ mask);
261	n/a	else {
262	n/a	aval = (unsigned char) seg << SEG_SHIFT;
263	n/a	if (seg < 2)
264	n/a	aval \|= (pcm_val >> 1) & QUANT_MASK;
265	n/a	else
266	n/a	aval \|= (pcm_val >> seg) & QUANT_MASK;
267	n/a	return (aval ^ mask);
268	n/a	}
269	n/a	}
270	n/a	/* End of code taken from sox */
271	n/a
272	n/a	/* Intel ADPCM step variation table */
273	n/a	static const int indexTable[16] = {
274	n/a	-1, -1, -1, -1, 2, 4, 6, 8,
275	n/a	-1, -1, -1, -1, 2, 4, 6, 8,
276	n/a	};
277	n/a
278	n/a	static const int stepsizeTable[89] = {
279	n/a	7, 8, 9, 10, 11, 12, 13, 14, 16, 17,
280	n/a	19, 21, 23, 25, 28, 31, 34, 37, 41, 45,
281	n/a	50, 55, 60, 66, 73, 80, 88, 97, 107, 118,
282	n/a	130, 143, 157, 173, 190, 209, 230, 253, 279, 307,
283	n/a	337, 371, 408, 449, 494, 544, 598, 658, 724, 796,
284	n/a	876, 963, 1060, 1166, 1282, 1411, 1552, 1707, 1878, 2066,
285	n/a	2272, 2499, 2749, 3024, 3327, 3660, 4026, 4428, 4871, 5358,
286	n/a	5894, 6484, 7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899,
287	n/a	15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767
288	n/a	};
289	n/a
290	n/a	#define GETINTX(T, cp, i) ((T )((unsigned char *)(cp) + (i)))
291	n/a	#define SETINTX(T, cp, i, val) do { \
292	n/a	(T )((unsigned char *)(cp) + (i)) = (T)(val); \
293	n/a	} while (0)
294	n/a
295	n/a
296	n/a	#define GETINT8(cp, i) GETINTX(signed char, (cp), (i))
297	n/a	#define GETINT16(cp, i) GETINTX(int16_t, (cp), (i))
298	n/a	#define GETINT32(cp, i) GETINTX(int32_t, (cp), (i))
299	n/a
300	n/a	#if WORDS_BIGENDIAN
301	n/a	#define GETINT24(cp, i) ( \
302	n/a	((unsigned char *)(cp) + (i))[2] + \
303	n/a	(((unsigned char *)(cp) + (i))[1] << 8) + \
304	n/a	(((signed char *)(cp) + (i))[0] << 16) )
305	n/a	#else
306	n/a	#define GETINT24(cp, i) ( \
307	n/a	((unsigned char *)(cp) + (i))[0] + \
308	n/a	(((unsigned char *)(cp) + (i))[1] << 8) + \
309	n/a	(((signed char *)(cp) + (i))[2] << 16) )
310	n/a	#endif
311	n/a
312	n/a
313	n/a	#define SETINT8(cp, i, val) SETINTX(signed char, (cp), (i), (val))
314	n/a	#define SETINT16(cp, i, val) SETINTX(int16_t, (cp), (i), (val))
315	n/a	#define SETINT32(cp, i, val) SETINTX(int32_t, (cp), (i), (val))
316	n/a
317	n/a	#if WORDS_BIGENDIAN
318	n/a	#define SETINT24(cp, i, val) do { \
319	n/a	((unsigned char *)(cp) + (i))[2] = (int)(val); \
320	n/a	((unsigned char *)(cp) + (i))[1] = (int)(val) >> 8; \
321	n/a	((signed char *)(cp) + (i))[0] = (int)(val) >> 16; \
322	n/a	} while (0)
323	n/a	#else
324	n/a	#define SETINT24(cp, i, val) do { \
325	n/a	((unsigned char *)(cp) + (i))[0] = (int)(val); \
326	n/a	((unsigned char *)(cp) + (i))[1] = (int)(val) >> 8; \
327	n/a	((signed char *)(cp) + (i))[2] = (int)(val) >> 16; \
328	n/a	} while (0)
329	n/a	#endif
330	n/a
331	n/a
332	n/a	#define GETRAWSAMPLE(size, cp, i) ( \
333	n/a	(size == 1) ? (int)GETINT8((cp), (i)) : \
334	n/a	(size == 2) ? (int)GETINT16((cp), (i)) : \
335	n/a	(size == 3) ? (int)GETINT24((cp), (i)) : \
336	n/a	(int)GETINT32((cp), (i)))
337	n/a
338	n/a	#define SETRAWSAMPLE(size, cp, i, val) do { \
339	n/a	if (size == 1) \
340	n/a	SETINT8((cp), (i), (val)); \
341	n/a	else if (size == 2) \
342	n/a	SETINT16((cp), (i), (val)); \
343	n/a	else if (size == 3) \
344	n/a	SETINT24((cp), (i), (val)); \
345	n/a	else \
346	n/a	SETINT32((cp), (i), (val)); \
347	n/a	} while(0)
348	n/a
349	n/a
350	n/a	#define GETSAMPLE32(size, cp, i) ( \
351	n/a	(size == 1) ? (int)GETINT8((cp), (i)) << 24 : \
352	n/a	(size == 2) ? (int)GETINT16((cp), (i)) << 16 : \
353	n/a	(size == 3) ? (int)GETINT24((cp), (i)) << 8 : \
354	n/a	(int)GETINT32((cp), (i)))
355	n/a
356	n/a	#define SETSAMPLE32(size, cp, i, val) do { \
357	n/a	if (size == 1) \
358	n/a	SETINT8((cp), (i), (val) >> 24); \
359	n/a	else if (size == 2) \
360	n/a	SETINT16((cp), (i), (val) >> 16); \
361	n/a	else if (size == 3) \
362	n/a	SETINT24((cp), (i), (val) >> 8); \
363	n/a	else \
364	n/a	SETINT32((cp), (i), (val)); \
365	n/a	} while(0)
366	n/a
367	n/a
368	n/a	static PyObject *AudioopError;
369	n/a
370	n/a	static int
371	n/a	audioop_check_size(int size)
372	n/a	{
373	n/a	if (size < 1 \|\| size > 4) {
374	n/a	PyErr_SetString(AudioopError, "Size should be 1, 2, 3 or 4");
375	n/a	return 0;
376	n/a	}
377	n/a	else
378	n/a	return 1;
379	n/a	}
380	n/a
381	n/a	static int
382	n/a	audioop_check_parameters(Py_ssize_t len, int size)
383	n/a	{
384	n/a	if (!audioop_check_size(size))
385	n/a	return 0;
386	n/a	if (len % size != 0) {
387	n/a	PyErr_SetString(AudioopError, "not a whole number of frames");
388	n/a	return 0;
389	n/a	}
390	n/a	return 1;
391	n/a	}
392	n/a
393	n/a	/*[clinic input]
394	n/a	module audioop
395	n/a	[clinic start generated code]*/
396	n/a	/[clinic end generated code: output=da39a3ee5e6b4b0d input=8fa8f6611be3591a]/
397	n/a
398	n/a	/*[clinic input]
399	n/a	audioop.getsample
400	n/a
401	n/a	fragment: Py_buffer
402	n/a	width: int
403	n/a	index: Py_ssize_t
404	n/a	/
405	n/a
406	n/a	Return the value of sample index from the fragment.
407	n/a	[clinic start generated code]*/
408	n/a
409	n/a	static PyObject *
410	n/a	audioop_getsample_impl(PyObject module, Py_buffer fragment, int width,
411	n/a	Py_ssize_t index)
412	n/a	/[clinic end generated code: output=8fe1b1775134f39a input=88edbe2871393549]/
413	n/a	{
414	n/a	int val;
415	n/a
416	n/a	if (!audioop_check_parameters(fragment->len, width))
417	n/a	return NULL;
418	n/a	if (index < 0 \|\| index >= fragment->len/width) {
419	n/a	PyErr_SetString(AudioopError, "Index out of range");
420	n/a	return NULL;
421	n/a	}
422	n/a	val = GETRAWSAMPLE(width, fragment->buf, index*width);
423	n/a	return PyLong_FromLong(val);
424	n/a	}
425	n/a
426	n/a	/*[clinic input]
427	n/a	audioop.max
428	n/a
429	n/a	fragment: Py_buffer
430	n/a	width: int
431	n/a	/
432	n/a
433	n/a	Return the maximum of the absolute value of all samples in a fragment.
434	n/a	[clinic start generated code]*/
435	n/a
436	n/a	static PyObject *
437	n/a	audioop_max_impl(PyObject module, Py_buffer fragment, int width)
438	n/a	/[clinic end generated code: output=e6c5952714f1c3f0 input=32bea5ea0ac8c223]/
439	n/a	{
440	n/a	Py_ssize_t i;
441	n/a	unsigned int absval, max = 0;
442	n/a
443	n/a	if (!audioop_check_parameters(fragment->len, width))
444	n/a	return NULL;
445	n/a	for (i = 0; i < fragment->len; i += width) {
446	n/a	int val = GETRAWSAMPLE(width, fragment->buf, i);
447	n/a	/* Cast to unsigned before negating. Unsigned overflow is well-
448	n/a	defined, but signed overflow is not. */
449	n/a	if (val < 0) absval = (unsigned int)-(int64_t)val;
450	n/a	else absval = val;
451	n/a	if (absval > max) max = absval;
452	n/a	}
453	n/a	return PyLong_FromUnsignedLong(max);
454	n/a	}
455	n/a
456	n/a	/*[clinic input]
457	n/a	audioop.minmax
458	n/a
459	n/a	fragment: Py_buffer
460	n/a	width: int
461	n/a	/
462	n/a
463	n/a	Return the minimum and maximum values of all samples in the sound fragment.
464	n/a	[clinic start generated code]*/
465	n/a
466	n/a	static PyObject *
467	n/a	audioop_minmax_impl(PyObject module, Py_buffer fragment, int width)
468	n/a	/[clinic end generated code: output=473fda66b15c836e input=89848e9b927a0696]/
469	n/a	{
470	n/a	Py_ssize_t i;
471	n/a	/* -1 trick below is needed on Windows to support -0x80000000 without
472	n/a	a warning */
473	n/a	int min = 0x7fffffff, max = -0x7FFFFFFF-1;
474	n/a
475	n/a	if (!audioop_check_parameters(fragment->len, width))
476	n/a	return NULL;
477	n/a	for (i = 0; i < fragment->len; i += width) {
478	n/a	int val = GETRAWSAMPLE(width, fragment->buf, i);
479	n/a	if (val > max) max = val;
480	n/a	if (val < min) min = val;
481	n/a	}
482	n/a	return Py_BuildValue("(ii)", min, max);
483	n/a	}
484	n/a
485	n/a	/*[clinic input]
486	n/a	audioop.avg
487	n/a
488	n/a	fragment: Py_buffer
489	n/a	width: int
490	n/a	/
491	n/a
492	n/a	Return the average over all samples in the fragment.
493	n/a	[clinic start generated code]*/
494	n/a
495	n/a	static PyObject *
496	n/a	audioop_avg_impl(PyObject module, Py_buffer fragment, int width)
497	n/a	/[clinic end generated code: output=4410a4c12c3586e6 input=1114493c7611334d]/
498	n/a	{
499	n/a	Py_ssize_t i;
500	n/a	int avg;
501	n/a	double sum = 0.0;
502	n/a
503	n/a	if (!audioop_check_parameters(fragment->len, width))
504	n/a	return NULL;
505	n/a	for (i = 0; i < fragment->len; i += width)
506	n/a	sum += GETRAWSAMPLE(width, fragment->buf, i);
507	n/a	if (fragment->len == 0)
508	n/a	avg = 0;
509	n/a	else
510	n/a	avg = (int)floor(sum / (double)(fragment->len/width));
511	n/a	return PyLong_FromLong(avg);
512	n/a	}
513	n/a
514	n/a	/*[clinic input]
515	n/a	audioop.rms
516	n/a
517	n/a	fragment: Py_buffer
518	n/a	width: int
519	n/a	/
520	n/a
521	n/a	Return the root-mean-square of the fragment, i.e. sqrt(sum(S_i^2)/n).
522	n/a	[clinic start generated code]*/
523	n/a
524	n/a	static PyObject *
525	n/a	audioop_rms_impl(PyObject module, Py_buffer fragment, int width)
526	n/a	/[clinic end generated code: output=1e7871c826445698 input=4cc57c6c94219d78]/
527	n/a	{
528	n/a	Py_ssize_t i;
529	n/a	unsigned int res;
530	n/a	double sum_squares = 0.0;
531	n/a
532	n/a	if (!audioop_check_parameters(fragment->len, width))
533	n/a	return NULL;
534	n/a	for (i = 0; i < fragment->len; i += width) {
535	n/a	double val = GETRAWSAMPLE(width, fragment->buf, i);
536	n/a	sum_squares += val*val;
537	n/a	}
538	n/a	if (fragment->len == 0)
539	n/a	res = 0;
540	n/a	else
541	n/a	res = (unsigned int)sqrt(sum_squares / (double)(fragment->len/width));
542	n/a	return PyLong_FromUnsignedLong(res);
543	n/a	}
544	n/a
545	n/a	static double _sum2(const int16_t a, const int16_t b, Py_ssize_t len)
546	n/a	{
547	n/a	Py_ssize_t i;
548	n/a	double sum = 0.0;
549	n/a
550	n/a	for( i=0; i<len; i++) {
551	n/a	sum = sum + (double)a[i]*(double)b[i];
552	n/a	}
553	n/a	return sum;
554	n/a	}
555	n/a
556	n/a	/*
557	n/a	** Findfit tries to locate a sample within another sample. Its main use
558	n/a	** is in echo-cancellation (to find the feedback of the output signal in
559	n/a	** the input signal).
560	n/a	** The method used is as follows:
561	n/a	**
562	n/a	** let R be the reference signal (length n) and A the input signal (length N)
563	n/a	** with N > n, and let all sums be over i from 0 to n-1.
564	n/a	**
565	n/a	** Now, for each j in {0..N-n} we compute a factor fj so that -fj*R matches A
566	n/a	** as good as possible, i.e. sum( (A[j+i]+fj*R[i])^2 ) is minimal. This
567	n/a	** equation gives fj = sum( A[j+i]R[i] ) / sum(R[i]^2).
568	n/a	**
569	n/a	** Next, we compute the relative distance between the original signal and
570	n/a	** the modified signal and minimize that over j:
571	n/a	** vj = sum( (A[j+i]-fj*R[i])^2 ) / sum( A[j+i]^2 ) =>
572	n/a	** vj = ( sum(A[j+i]^2)*sum(R[i]^2) - sum(A[j+i]R[i])^2 ) / sum( A[j+i]^2 )
573	n/a	**
574	n/a	** In the code variables correspond as follows:
575	n/a	** cp1 A
576	n/a	** cp2 R
577	n/a	** len1 N
578	n/a	** len2 n
579	n/a	** aj_m1 A[j-1]
580	n/a	** aj_lm1 A[j+n-1]
581	n/a	** sum_ri_2 sum(R[i]^2)
582	n/a	** sum_aij_2 sum(A[i+j]^2)
583	n/a	** sum_aij_ri sum(A[i+j]R[i])
584	n/a	**
585	n/a	** sum_ri is calculated once, sum_aij_2 is updated each step and sum_aij_ri
586	n/a	** is completely recalculated each step.
587	n/a	*/
588	n/a	/*[clinic input]
589	n/a	audioop.findfit
590	n/a
591	n/a	fragment: Py_buffer
592	n/a	reference: Py_buffer
593	n/a	/
594	n/a
595	n/a	Try to match reference as well as possible to a portion of fragment.
596	n/a	[clinic start generated code]*/
597	n/a
598	n/a	static PyObject *
599	n/a	audioop_findfit_impl(PyObject module, Py_buffer fragment,
600	n/a	Py_buffer *reference)
601	n/a	/[clinic end generated code: output=5752306d83cbbada input=62c305605e183c9a]/
602	n/a	{
603	n/a	const int16_t cp1, cp2;
604	n/a	Py_ssize_t len1, len2;
605	n/a	Py_ssize_t j, best_j;
606	n/a	double aj_m1, aj_lm1;
607	n/a	double sum_ri_2, sum_aij_2, sum_aij_ri, result, best_result, factor;
608	n/a
609	n/a	if (fragment->len & 1 \|\| reference->len & 1) {
610	n/a	PyErr_SetString(AudioopError, "Strings should be even-sized");
611	n/a	return NULL;
612	n/a	}
613	n/a	cp1 = (const int16_t *)fragment->buf;
614	n/a	len1 = fragment->len >> 1;
615	n/a	cp2 = (const int16_t *)reference->buf;
616	n/a	len2 = reference->len >> 1;
617	n/a
618	n/a	if (len1 < len2) {
619	n/a	PyErr_SetString(AudioopError, "First sample should be longer");
620	n/a	return NULL;
621	n/a	}
622	n/a	sum_ri_2 = _sum2(cp2, cp2, len2);
623	n/a	sum_aij_2 = _sum2(cp1, cp1, len2);
624	n/a	sum_aij_ri = _sum2(cp1, cp2, len2);
625	n/a
626	n/a	result = (sum_ri_2sum_aij_2 - sum_aij_risum_aij_ri) / sum_aij_2;
627	n/a
628	n/a	best_result = result;
629	n/a	best_j = 0;
630	n/a
631	n/a	for ( j=1; j<=len1-len2; j++) {
632	n/a	aj_m1 = (double)cp1[j-1];
633	n/a	aj_lm1 = (double)cp1[j+len2-1];
634	n/a
635	n/a	sum_aij_2 = sum_aij_2 + aj_lm1aj_lm1 - aj_m1aj_m1;
636	n/a	sum_aij_ri = _sum2(cp1+j, cp2, len2);
637	n/a
638	n/a	result = (sum_ri_2sum_aij_2 - sum_aij_risum_aij_ri)
639	n/a	/ sum_aij_2;
640	n/a
641	n/a	if ( result < best_result ) {
642	n/a	best_result = result;
643	n/a	best_j = j;
644	n/a	}
645	n/a
646	n/a	}
647	n/a
648	n/a	factor = _sum2(cp1+best_j, cp2, len2) / sum_ri_2;
649	n/a
650	n/a	return Py_BuildValue("(nf)", best_j, factor);
651	n/a	}
652	n/a
653	n/a	/*
654	n/a	** findfactor finds a factor f so that the energy in A-fB is minimal.
655	n/a	** See the comment for findfit for details.
656	n/a	*/
657	n/a	/*[clinic input]
658	n/a	audioop.findfactor
659	n/a
660	n/a	fragment: Py_buffer
661	n/a	reference: Py_buffer
662	n/a	/
663	n/a
664	n/a	Return a factor F such that rms(add(fragment, mul(reference, -F))) is minimal.
665	n/a	[clinic start generated code]*/
666	n/a
667	n/a	static PyObject *
668	n/a	audioop_findfactor_impl(PyObject module, Py_buffer fragment,
669	n/a	Py_buffer *reference)
670	n/a	/[clinic end generated code: output=14ea95652c1afcf8 input=816680301d012b21]/
671	n/a	{
672	n/a	const int16_t cp1, cp2;
673	n/a	Py_ssize_t len;
674	n/a	double sum_ri_2, sum_aij_ri, result;
675	n/a
676	n/a	if (fragment->len & 1 \|\| reference->len & 1) {
677	n/a	PyErr_SetString(AudioopError, "Strings should be even-sized");
678	n/a	return NULL;
679	n/a	}
680	n/a	if (fragment->len != reference->len) {
681	n/a	PyErr_SetString(AudioopError, "Samples should be same size");
682	n/a	return NULL;
683	n/a	}
684	n/a	cp1 = (const int16_t *)fragment->buf;
685	n/a	cp2 = (const int16_t *)reference->buf;
686	n/a	len = fragment->len >> 1;
687	n/a	sum_ri_2 = _sum2(cp2, cp2, len);
688	n/a	sum_aij_ri = _sum2(cp1, cp2, len);
689	n/a
690	n/a	result = sum_aij_ri / sum_ri_2;
691	n/a
692	n/a	return PyFloat_FromDouble(result);
693	n/a	}
694	n/a
695	n/a	/*
696	n/a	** findmax returns the index of the n-sized segment of the input sample
697	n/a	** that contains the most energy.
698	n/a	*/
699	n/a	/*[clinic input]
700	n/a	audioop.findmax
701	n/a
702	n/a	fragment: Py_buffer
703	n/a	length: Py_ssize_t
704	n/a	/
705	n/a
706	n/a	Search fragment for a slice of specified number of samples with maximum energy.
707	n/a	[clinic start generated code]*/
708	n/a
709	n/a	static PyObject *
710	n/a	audioop_findmax_impl(PyObject module, Py_buffer fragment,
711	n/a	Py_ssize_t length)
712	n/a	/[clinic end generated code: output=f008128233523040 input=2f304801ed42383c]/
713	n/a	{
714	n/a	const int16_t *cp1;
715	n/a	Py_ssize_t len1;
716	n/a	Py_ssize_t j, best_j;
717	n/a	double aj_m1, aj_lm1;
718	n/a	double result, best_result;
719	n/a
720	n/a	if (fragment->len & 1) {
721	n/a	PyErr_SetString(AudioopError, "Strings should be even-sized");
722	n/a	return NULL;
723	n/a	}
724	n/a	cp1 = (const int16_t *)fragment->buf;
725	n/a	len1 = fragment->len >> 1;
726	n/a
727	n/a	if (length < 0 \|\| len1 < length) {
728	n/a	PyErr_SetString(AudioopError, "Input sample should be longer");
729	n/a	return NULL;
730	n/a	}
731	n/a
732	n/a	result = _sum2(cp1, cp1, length);
733	n/a
734	n/a	best_result = result;
735	n/a	best_j = 0;
736	n/a
737	n/a	for ( j=1; j<=len1-length; j++) {
738	n/a	aj_m1 = (double)cp1[j-1];
739	n/a	aj_lm1 = (double)cp1[j+length-1];
740	n/a
741	n/a	result = result + aj_lm1aj_lm1 - aj_m1aj_m1;
742	n/a
743	n/a	if ( result > best_result ) {
744	n/a	best_result = result;
745	n/a	best_j = j;
746	n/a	}
747	n/a
748	n/a	}
749	n/a
750	n/a	return PyLong_FromSsize_t(best_j);
751	n/a	}
752	n/a
753	n/a	/*[clinic input]
754	n/a	audioop.avgpp
755	n/a
756	n/a	fragment: Py_buffer
757	n/a	width: int
758	n/a	/
759	n/a
760	n/a	Return the average peak-peak value over all samples in the fragment.
761	n/a	[clinic start generated code]*/
762	n/a
763	n/a	static PyObject *
764	n/a	audioop_avgpp_impl(PyObject module, Py_buffer fragment, int width)
765	n/a	/[clinic end generated code: output=269596b0d5ae0b2b input=0b3cceeae420a7d9]/
766	n/a	{
767	n/a	Py_ssize_t i;
768	n/a	int prevval, prevextremevalid = 0, prevextreme = 0;
769	n/a	double sum = 0.0;
770	n/a	unsigned int avg;
771	n/a	int diff, prevdiff, nextreme = 0;
772	n/a
773	n/a	if (!audioop_check_parameters(fragment->len, width))
774	n/a	return NULL;
775	n/a	if (fragment->len <= width)
776	n/a	return PyLong_FromLong(0);
777	n/a	prevval = GETRAWSAMPLE(width, fragment->buf, 0);
778	n/a	prevdiff = 17; /* Anything != 0, 1 */
779	n/a	for (i = width; i < fragment->len; i += width) {
780	n/a	int val = GETRAWSAMPLE(width, fragment->buf, i);
781	n/a	if (val != prevval) {
782	n/a	diff = val < prevval;
783	n/a	if (prevdiff == !diff) {
784	n/a	/* Derivative changed sign. Compute difference to last
785	n/a	** extreme value and remember.
786	n/a	*/
787	n/a	if (prevextremevalid) {
788	n/a	if (prevval < prevextreme)
789	n/a	sum += (double)((unsigned int)prevextreme -
790	n/a	(unsigned int)prevval);
791	n/a	else
792	n/a	sum += (double)((unsigned int)prevval -
793	n/a	(unsigned int)prevextreme);
794	n/a	nextreme++;
795	n/a	}
796	n/a	prevextremevalid = 1;
797	n/a	prevextreme = prevval;
798	n/a	}
799	n/a	prevval = val;
800	n/a	prevdiff = diff;
801	n/a	}
802	n/a	}
803	n/a	if ( nextreme == 0 )
804	n/a	avg = 0;
805	n/a	else
806	n/a	avg = (unsigned int)(sum / (double)nextreme);
807	n/a	return PyLong_FromUnsignedLong(avg);
808	n/a	}
809	n/a
810	n/a	/*[clinic input]
811	n/a	audioop.maxpp
812	n/a
813	n/a	fragment: Py_buffer
814	n/a	width: int
815	n/a	/
816	n/a
817	n/a	Return the maximum peak-peak value in the sound fragment.
818	n/a	[clinic start generated code]*/
819	n/a
820	n/a	static PyObject *
821	n/a	audioop_maxpp_impl(PyObject module, Py_buffer fragment, int width)
822	n/a	/[clinic end generated code: output=5b918ed5dbbdb978 input=671a13e1518f80a1]/
823	n/a	{
824	n/a	Py_ssize_t i;
825	n/a	int prevval, prevextremevalid = 0, prevextreme = 0;
826	n/a	unsigned int max = 0, extremediff;
827	n/a	int diff, prevdiff;
828	n/a
829	n/a	if (!audioop_check_parameters(fragment->len, width))
830	n/a	return NULL;
831	n/a	if (fragment->len <= width)
832	n/a	return PyLong_FromLong(0);
833	n/a	prevval = GETRAWSAMPLE(width, fragment->buf, 0);
834	n/a	prevdiff = 17; /* Anything != 0, 1 */
835	n/a	for (i = width; i < fragment->len; i += width) {
836	n/a	int val = GETRAWSAMPLE(width, fragment->buf, i);
837	n/a	if (val != prevval) {
838	n/a	diff = val < prevval;
839	n/a	if (prevdiff == !diff) {
840	n/a	/* Derivative changed sign. Compute difference to
841	n/a	** last extreme value and remember.
842	n/a	*/
843	n/a	if (prevextremevalid) {
844	n/a	if (prevval < prevextreme)
845	n/a	extremediff = (unsigned int)prevextreme -
846	n/a	(unsigned int)prevval;
847	n/a	else
848	n/a	extremediff = (unsigned int)prevval -
849	n/a	(unsigned int)prevextreme;
850	n/a	if ( extremediff > max )
851	n/a	max = extremediff;
852	n/a	}
853	n/a	prevextremevalid = 1;
854	n/a	prevextreme = prevval;
855	n/a	}
856	n/a	prevval = val;
857	n/a	prevdiff = diff;
858	n/a	}
859	n/a	}
860	n/a	return PyLong_FromUnsignedLong(max);
861	n/a	}
862	n/a
863	n/a	/*[clinic input]
864	n/a	audioop.cross
865	n/a
866	n/a	fragment: Py_buffer
867	n/a	width: int
868	n/a	/
869	n/a
870	n/a	Return the number of zero crossings in the fragment passed as an argument.
871	n/a	[clinic start generated code]*/
872	n/a
873	n/a	static PyObject *
874	n/a	audioop_cross_impl(PyObject module, Py_buffer fragment, int width)
875	n/a	/[clinic end generated code: output=5938dcdd74a1f431 input=b1b3f15b83f6b41a]/
876	n/a	{
877	n/a	Py_ssize_t i;
878	n/a	int prevval;
879	n/a	Py_ssize_t ncross;
880	n/a
881	n/a	if (!audioop_check_parameters(fragment->len, width))
882	n/a	return NULL;
883	n/a	ncross = -1;
884	n/a	prevval = 17; /* Anything <> 0,1 */
885	n/a	for (i = 0; i < fragment->len; i += width) {
886	n/a	int val = GETRAWSAMPLE(width, fragment->buf, i) < 0;
887	n/a	if (val != prevval) ncross++;
888	n/a	prevval = val;
889	n/a	}
890	n/a	return PyLong_FromSsize_t(ncross);
891	n/a	}
892	n/a
893	n/a	/*[clinic input]
894	n/a	audioop.mul
895	n/a
896	n/a	fragment: Py_buffer
897	n/a	width: int
898	n/a	factor: double
899	n/a	/
900	n/a
901	n/a	Return a fragment that has all samples in the original fragment multiplied by the floating-point value factor.
902	n/a	[clinic start generated code]*/
903	n/a
904	n/a	static PyObject *
905	n/a	audioop_mul_impl(PyObject module, Py_buffer fragment, int width,
906	n/a	double factor)
907	n/a	/[clinic end generated code: output=6cd48fe796da0ea4 input=c726667baa157d3c]/
908	n/a	{
909	n/a	signed char *ncp;
910	n/a	Py_ssize_t i;
911	n/a	double maxval, minval;
912	n/a	PyObject *rv;
913	n/a
914	n/a	if (!audioop_check_parameters(fragment->len, width))
915	n/a	return NULL;
916	n/a
917	n/a	maxval = (double) maxvals[width];
918	n/a	minval = (double) minvals[width];
919	n/a
920	n/a	rv = PyBytes_FromStringAndSize(NULL, fragment->len);
921	n/a	if (rv == NULL)
922	n/a	return NULL;
923	n/a	ncp = (signed char *)PyBytes_AsString(rv);
924	n/a
925	n/a	for (i = 0; i < fragment->len; i += width) {
926	n/a	double val = GETRAWSAMPLE(width, fragment->buf, i);
927	n/a	val *= factor;
928	n/a	val = floor(fbound(val, minval, maxval));
929	n/a	SETRAWSAMPLE(width, ncp, i, (int)val);
930	n/a	}
931	n/a	return rv;
932	n/a	}
933	n/a
934	n/a	/*[clinic input]
935	n/a	audioop.tomono
936	n/a
937	n/a	fragment: Py_buffer
938	n/a	width: int
939	n/a	lfactor: double
940	n/a	rfactor: double
941	n/a	/
942	n/a
943	n/a	Convert a stereo fragment to a mono fragment.
944	n/a	[clinic start generated code]*/
945	n/a
946	n/a	static PyObject *
947	n/a	audioop_tomono_impl(PyObject module, Py_buffer fragment, int width,
948	n/a	double lfactor, double rfactor)
949	n/a	/[clinic end generated code: output=235c8277216d4e4e input=c4ec949b3f4dddfa]/
950	n/a	{
951	n/a	signed char cp, ncp;
952	n/a	Py_ssize_t len, i;
953	n/a	double maxval, minval;
954	n/a	PyObject *rv;
955	n/a
956	n/a	cp = fragment->buf;
957	n/a	len = fragment->len;
958	n/a	if (!audioop_check_parameters(len, width))
959	n/a	return NULL;
960	n/a	if (((len / width) & 1) != 0) {
961	n/a	PyErr_SetString(AudioopError, "not a whole number of frames");
962	n/a	return NULL;
963	n/a	}
964	n/a
965	n/a	maxval = (double) maxvals[width];
966	n/a	minval = (double) minvals[width];
967	n/a
968	n/a	rv = PyBytes_FromStringAndSize(NULL, len/2);
969	n/a	if (rv == NULL)
970	n/a	return NULL;
971	n/a	ncp = (signed char *)PyBytes_AsString(rv);
972	n/a
973	n/a	for (i = 0; i < len; i += width*2) {
974	n/a	double val1 = GETRAWSAMPLE(width, cp, i);
975	n/a	double val2 = GETRAWSAMPLE(width, cp, i + width);
976	n/a	double val = val1lfactor + val2rfactor;
977	n/a	val = floor(fbound(val, minval, maxval));
978	n/a	SETRAWSAMPLE(width, ncp, i/2, val);
979	n/a	}
980	n/a	return rv;
981	n/a	}
982	n/a
983	n/a	/*[clinic input]
984	n/a	audioop.tostereo
985	n/a
986	n/a	fragment: Py_buffer
987	n/a	width: int
988	n/a	lfactor: double
989	n/a	rfactor: double
990	n/a	/
991	n/a
992	n/a	Generate a stereo fragment from a mono fragment.
993	n/a	[clinic start generated code]*/
994	n/a
995	n/a	static PyObject *
996	n/a	audioop_tostereo_impl(PyObject module, Py_buffer fragment, int width,
997	n/a	double lfactor, double rfactor)
998	n/a	/[clinic end generated code: output=046f13defa5f1595 input=27b6395ebfdff37a]/
999	n/a	{
1000	n/a	signed char *ncp;
1001	n/a	Py_ssize_t i;
1002	n/a	double maxval, minval;
1003	n/a	PyObject *rv;
1004	n/a
1005	n/a	if (!audioop_check_parameters(fragment->len, width))
1006	n/a	return NULL;
1007	n/a
1008	n/a	maxval = (double) maxvals[width];
1009	n/a	minval = (double) minvals[width];
1010	n/a
1011	n/a	if (fragment->len > PY_SSIZE_T_MAX/2) {
1012	n/a	PyErr_SetString(PyExc_MemoryError,
1013	n/a	"not enough memory for output buffer");
1014	n/a	return NULL;
1015	n/a	}
1016	n/a
1017	n/a	rv = PyBytes_FromStringAndSize(NULL, fragment->len*2);
1018	n/a	if (rv == NULL)
1019	n/a	return NULL;
1020	n/a	ncp = (signed char *)PyBytes_AsString(rv);
1021	n/a
1022	n/a	for (i = 0; i < fragment->len; i += width) {
1023	n/a	double val = GETRAWSAMPLE(width, fragment->buf, i);
1024	n/a	int val1 = (int)floor(fbound(val*lfactor, minval, maxval));
1025	n/a	int val2 = (int)floor(fbound(val*rfactor, minval, maxval));
1026	n/a	SETRAWSAMPLE(width, ncp, i*2, val1);
1027	n/a	SETRAWSAMPLE(width, ncp, i*2 + width, val2);
1028	n/a	}
1029	n/a	return rv;
1030	n/a	}
1031	n/a
1032	n/a	/*[clinic input]
1033	n/a	audioop.add
1034	n/a
1035	n/a	fragment1: Py_buffer
1036	n/a	fragment2: Py_buffer
1037	n/a	width: int
1038	n/a	/
1039	n/a
1040	n/a	Return a fragment which is the addition of the two samples passed as parameters.
1041	n/a	[clinic start generated code]*/
1042	n/a
1043	n/a	static PyObject *
1044	n/a	audioop_add_impl(PyObject module, Py_buffer fragment1,
1045	n/a	Py_buffer *fragment2, int width)
1046	n/a	/[clinic end generated code: output=60140af4d1aab6f2 input=4a8d4bae4c1605c7]/
1047	n/a	{
1048	n/a	signed char *ncp;
1049	n/a	Py_ssize_t i;
1050	n/a	int minval, maxval, newval;
1051	n/a	PyObject *rv;
1052	n/a
1053	n/a	if (!audioop_check_parameters(fragment1->len, width))
1054	n/a	return NULL;
1055	n/a	if (fragment1->len != fragment2->len) {
1056	n/a	PyErr_SetString(AudioopError, "Lengths should be the same");
1057	n/a	return NULL;
1058	n/a	}
1059	n/a
1060	n/a	maxval = maxvals[width];
1061	n/a	minval = minvals[width];
1062	n/a
1063	n/a	rv = PyBytes_FromStringAndSize(NULL, fragment1->len);
1064	n/a	if (rv == NULL)
1065	n/a	return NULL;
1066	n/a	ncp = (signed char *)PyBytes_AsString(rv);
1067	n/a
1068	n/a	for (i = 0; i < fragment1->len; i += width) {
1069	n/a	int val1 = GETRAWSAMPLE(width, fragment1->buf, i);
1070	n/a	int val2 = GETRAWSAMPLE(width, fragment2->buf, i);
1071	n/a
1072	n/a	if (width < 4) {
1073	n/a	newval = val1 + val2;
1074	n/a	/* truncate in case of overflow */
1075	n/a	if (newval > maxval)
1076	n/a	newval = maxval;
1077	n/a	else if (newval < minval)
1078	n/a	newval = minval;
1079	n/a	}
1080	n/a	else {
1081	n/a	double fval = (double)val1 + (double)val2;
1082	n/a	/* truncate in case of overflow */
1083	n/a	newval = (int)floor(fbound(fval, minval, maxval));
1084	n/a	}
1085	n/a
1086	n/a	SETRAWSAMPLE(width, ncp, i, newval);
1087	n/a	}
1088	n/a	return rv;
1089	n/a	}
1090	n/a
1091	n/a	/*[clinic input]
1092	n/a	audioop.bias
1093	n/a
1094	n/a	fragment: Py_buffer
1095	n/a	width: int
1096	n/a	bias: int
1097	n/a	/
1098	n/a
1099	n/a	Return a fragment that is the original fragment with a bias added to each sample.
1100	n/a	[clinic start generated code]*/
1101	n/a
1102	n/a	static PyObject *
1103	n/a	audioop_bias_impl(PyObject module, Py_buffer fragment, int width, int bias)
1104	n/a	/[clinic end generated code: output=6e0aa8f68f045093 input=2b5cce5c3bb4838c]/
1105	n/a	{
1106	n/a	signed char *ncp;
1107	n/a	Py_ssize_t i;
1108	n/a	unsigned int val = 0, mask;
1109	n/a	PyObject *rv;
1110	n/a
1111	n/a	if (!audioop_check_parameters(fragment->len, width))
1112	n/a	return NULL;
1113	n/a
1114	n/a	rv = PyBytes_FromStringAndSize(NULL, fragment->len);
1115	n/a	if (rv == NULL)
1116	n/a	return NULL;
1117	n/a	ncp = (signed char *)PyBytes_AsString(rv);
1118	n/a
1119	n/a	mask = masks[width];
1120	n/a
1121	n/a	for (i = 0; i < fragment->len; i += width) {
1122	n/a	if (width == 1)
1123	n/a	val = GETINTX(unsigned char, fragment->buf, i);
1124	n/a	else if (width == 2)
1125	n/a	val = GETINTX(uint16_t, fragment->buf, i);
1126	n/a	else if (width == 3)
1127	n/a	val = ((unsigned int)GETINT24(fragment->buf, i)) & 0xffffffu;
1128	n/a	else {
1129	n/a	assert(width == 4);
1130	n/a	val = GETINTX(uint32_t, fragment->buf, i);
1131	n/a	}
1132	n/a
1133	n/a	val += (unsigned int)bias;
1134	n/a	/* wrap around in case of overflow */
1135	n/a	val &= mask;
1136	n/a
1137	n/a	if (width == 1)
1138	n/a	SETINTX(unsigned char, ncp, i, val);
1139	n/a	else if (width == 2)
1140	n/a	SETINTX(uint16_t, ncp, i, val);
1141	n/a	else if (width == 3)
1142	n/a	SETINT24(ncp, i, (int)val);
1143	n/a	else {
1144	n/a	assert(width == 4);
1145	n/a	SETINTX(uint32_t, ncp, i, val);
1146	n/a	}
1147	n/a	}
1148	n/a	return rv;
1149	n/a	}
1150	n/a
1151	n/a	/*[clinic input]
1152	n/a	audioop.reverse
1153	n/a
1154	n/a	fragment: Py_buffer
1155	n/a	width: int
1156	n/a	/
1157	n/a
1158	n/a	Reverse the samples in a fragment and returns the modified fragment.
1159	n/a	[clinic start generated code]*/
1160	n/a
1161	n/a	static PyObject *
1162	n/a	audioop_reverse_impl(PyObject module, Py_buffer fragment, int width)
1163	n/a	/[clinic end generated code: output=b44135698418da14 input=668f890cf9f9d225]/
1164	n/a	{
1165	n/a	unsigned char *ncp;
1166	n/a	Py_ssize_t i;
1167	n/a	PyObject *rv;
1168	n/a
1169	n/a	if (!audioop_check_parameters(fragment->len, width))
1170	n/a	return NULL;
1171	n/a
1172	n/a	rv = PyBytes_FromStringAndSize(NULL, fragment->len);
1173	n/a	if (rv == NULL)
1174	n/a	return NULL;
1175	n/a	ncp = (unsigned char *)PyBytes_AsString(rv);
1176	n/a
1177	n/a	for (i = 0; i < fragment->len; i += width) {
1178	n/a	int val = GETRAWSAMPLE(width, fragment->buf, i);
1179	n/a	SETRAWSAMPLE(width, ncp, fragment->len - i - width, val);
1180	n/a	}
1181	n/a	return rv;
1182	n/a	}
1183	n/a
1184	n/a	/*[clinic input]
1185	n/a	audioop.byteswap
1186	n/a
1187	n/a	fragment: Py_buffer
1188	n/a	width: int
1189	n/a	/
1190	n/a
1191	n/a	Convert big-endian samples to little-endian and vice versa.
1192	n/a	[clinic start generated code]*/
1193	n/a
1194	n/a	static PyObject *
1195	n/a	audioop_byteswap_impl(PyObject module, Py_buffer fragment, int width)
1196	n/a	/[clinic end generated code: output=50838a9e4b87cd4d input=fae7611ceffa5c82]/
1197	n/a	{
1198	n/a	unsigned char *ncp;
1199	n/a	Py_ssize_t i;
1200	n/a	PyObject *rv;
1201	n/a
1202	n/a	if (!audioop_check_parameters(fragment->len, width))
1203	n/a	return NULL;
1204	n/a
1205	n/a	rv = PyBytes_FromStringAndSize(NULL, fragment->len);
1206	n/a	if (rv == NULL)
1207	n/a	return NULL;
1208	n/a	ncp = (unsigned char *)PyBytes_AsString(rv);
1209	n/a
1210	n/a	for (i = 0; i < fragment->len; i += width) {
1211	n/a	int j;
1212	n/a	for (j = 0; j < width; j++)
1213	n/a	ncp[i + width - 1 - j] = ((unsigned char *)fragment->buf)[i + j];
1214	n/a	}
1215	n/a	return rv;
1216	n/a	}
1217	n/a
1218	n/a	/*[clinic input]
1219	n/a	audioop.lin2lin
1220	n/a
1221	n/a	fragment: Py_buffer
1222	n/a	width: int
1223	n/a	newwidth: int
1224	n/a	/
1225	n/a
1226	n/a	Convert samples between 1-, 2-, 3- and 4-byte formats.
1227	n/a	[clinic start generated code]*/
1228	n/a
1229	n/a	static PyObject *
1230	n/a	audioop_lin2lin_impl(PyObject module, Py_buffer fragment, int width,
1231	n/a	int newwidth)
1232	n/a	/[clinic end generated code: output=17b14109248f1d99 input=5ce08c8aa2f24d96]/
1233	n/a	{
1234	n/a	unsigned char *ncp;
1235	n/a	Py_ssize_t i, j;
1236	n/a	PyObject *rv;
1237	n/a
1238	n/a	if (!audioop_check_parameters(fragment->len, width))
1239	n/a	return NULL;
1240	n/a	if (!audioop_check_size(newwidth))
1241	n/a	return NULL;
1242	n/a
1243	n/a	if (fragment->len/width > PY_SSIZE_T_MAX/newwidth) {
1244	n/a	PyErr_SetString(PyExc_MemoryError,
1245	n/a	"not enough memory for output buffer");
1246	n/a	return NULL;
1247	n/a	}
1248	n/a	rv = PyBytes_FromStringAndSize(NULL, (fragment->len/width)*newwidth);
1249	n/a	if (rv == NULL)
1250	n/a	return NULL;
1251	n/a	ncp = (unsigned char *)PyBytes_AsString(rv);
1252	n/a
1253	n/a	for (i = j = 0; i < fragment->len; i += width, j += newwidth) {
1254	n/a	int val = GETSAMPLE32(width, fragment->buf, i);
1255	n/a	SETSAMPLE32(newwidth, ncp, j, val);
1256	n/a	}
1257	n/a	return rv;
1258	n/a	}
1259	n/a
1260	n/a	static int
1261	n/a	gcd(int a, int b)
1262	n/a	{
1263	n/a	while (b > 0) {
1264	n/a	int tmp = a % b;
1265	n/a	a = b;
1266	n/a	b = tmp;
1267	n/a	}
1268	n/a	return a;
1269	n/a	}
1270	n/a
1271	n/a	/*[clinic input]
1272	n/a	audioop.ratecv
1273	n/a
1274	n/a	fragment: Py_buffer
1275	n/a	width: int
1276	n/a	nchannels: int
1277	n/a	inrate: int
1278	n/a	outrate: int
1279	n/a	state: object
1280	n/a	weightA: int = 1
1281	n/a	weightB: int = 0
1282	n/a	/
1283	n/a
1284	n/a	Convert the frame rate of the input fragment.
1285	n/a	[clinic start generated code]*/
1286	n/a
1287	n/a	static PyObject *
1288	n/a	audioop_ratecv_impl(PyObject module, Py_buffer fragment, int width,
1289	n/a	int nchannels, int inrate, int outrate, PyObject *state,
1290	n/a	int weightA, int weightB)
1291	n/a	/[clinic end generated code: output=624038e843243139 input=aff3acdc94476191]/
1292	n/a	{
1293	n/a	char cp, ncp;
1294	n/a	Py_ssize_t len;
1295	n/a	int chan, d, prev_i, cur_i, cur_o;
1296	n/a	PyObject samps, str, *rv = NULL;
1297	n/a	int bytes_per_frame;
1298	n/a
1299	n/a	if (!audioop_check_size(width))
1300	n/a	return NULL;
1301	n/a	if (nchannels < 1) {
1302	n/a	PyErr_SetString(AudioopError, "# of channels should be >= 1");
1303	n/a	return NULL;
1304	n/a	}
1305	n/a	if (width > INT_MAX / nchannels) {
1306	n/a	/* This overflow test is rigorously correct because
1307	n/a	both multiplicands are >= 1. Use the argument names
1308	n/a	from the docs for the error msg. */
1309	n/a	PyErr_SetString(PyExc_OverflowError,
1310	n/a	"width * nchannels too big for a C int");
1311	n/a	return NULL;
1312	n/a	}
1313	n/a	bytes_per_frame = width * nchannels;
1314	n/a	if (weightA < 1 \|\| weightB < 0) {
1315	n/a	PyErr_SetString(AudioopError,
1316	n/a	"weightA should be >= 1, weightB should be >= 0");
1317	n/a	return NULL;
1318	n/a	}
1319	n/a	assert(fragment->len >= 0);
1320	n/a	if (fragment->len % bytes_per_frame != 0) {
1321	n/a	PyErr_SetString(AudioopError, "not a whole number of frames");
1322	n/a	return NULL;
1323	n/a	}
1324	n/a	if (inrate <= 0 \|\| outrate <= 0) {
1325	n/a	PyErr_SetString(AudioopError, "sampling rate not > 0");
1326	n/a	return NULL;
1327	n/a	}
1328	n/a	/* divide inrate and outrate by their greatest common divisor */
1329	n/a	d = gcd(inrate, outrate);
1330	n/a	inrate /= d;
1331	n/a	outrate /= d;
1332	n/a	/* divide weightA and weightB by their greatest common divisor */
1333	n/a	d = gcd(weightA, weightB);
1334	n/a	weightA /= d;
1335	n/a	weightB /= d;
1336	n/a
1337	n/a	if ((size_t)nchannels > SIZE_MAX/sizeof(int)) {
1338	n/a	PyErr_SetString(PyExc_MemoryError,
1339	n/a	"not enough memory for output buffer");
1340	n/a	return NULL;
1341	n/a	}
1342	n/a	prev_i = (int ) PyMem_Malloc(nchannels sizeof(int));
1343	n/a	cur_i = (int ) PyMem_Malloc(nchannels sizeof(int));
1344	n/a	if (prev_i == NULL \|\| cur_i == NULL) {
1345	n/a	(void) PyErr_NoMemory();
1346	n/a	goto exit;
1347	n/a	}
1348	n/a
1349	n/a	len = fragment->len / bytes_per_frame; /* # of frames */
1350	n/a
1351	n/a	if (state == Py_None) {
1352	n/a	d = -outrate;
1353	n/a	for (chan = 0; chan < nchannels; chan++)
1354	n/a	prev_i[chan] = cur_i[chan] = 0;
1355	n/a	}
1356	n/a	else {
1357	n/a	if (!PyArg_ParseTuple(state,
1358	n/a	"iO!;audioop.ratecv: illegal state argument",
1359	n/a	&d, &PyTuple_Type, &samps))
1360	n/a	goto exit;
1361	n/a	if (PyTuple_Size(samps) != nchannels) {
1362	n/a	PyErr_SetString(AudioopError,
1363	n/a	"illegal state argument");
1364	n/a	goto exit;
1365	n/a	}
1366	n/a	for (chan = 0; chan < nchannels; chan++) {
1367	n/a	if (!PyArg_ParseTuple(PyTuple_GetItem(samps, chan),
1368	n/a	"ii:ratecv", &prev_i[chan],
1369	n/a	&cur_i[chan]))
1370	n/a	goto exit;
1371	n/a	}
1372	n/a	}
1373	n/a
1374	n/a	/* str <- Space for the output buffer. */
1375	n/a	if (len == 0)
1376	n/a	str = PyBytes_FromStringAndSize(NULL, 0);
1377	n/a	else {
1378	n/a	/* There are len input frames, so we need (mathematically)
1379	n/a	ceiling(len*outrate/inrate) output frames, and each frame
1380	n/a	requires bytes_per_frame bytes. Computing this
1381	n/a	without spurious overflow is the challenge; we can
1382	n/a	settle for a reasonable upper bound, though, in this
1383	n/a	case ceiling(len/inrate) * outrate. */
1384	n/a
1385	n/a	/* compute ceiling(len/inrate) without overflow */
1386	n/a	Py_ssize_t q = 1 + (len - 1) / inrate;
1387	n/a	if (outrate > PY_SSIZE_T_MAX / q / bytes_per_frame)
1388	n/a	str = NULL;
1389	n/a	else
1390	n/a	str = PyBytes_FromStringAndSize(NULL,
1391	n/a	q * outrate * bytes_per_frame);
1392	n/a	}
1393	n/a	if (str == NULL) {
1394	n/a	PyErr_SetString(PyExc_MemoryError,
1395	n/a	"not enough memory for output buffer");
1396	n/a	goto exit;
1397	n/a	}
1398	n/a	ncp = PyBytes_AsString(str);
1399	n/a	cp = fragment->buf;
1400	n/a
1401	n/a	for (;;) {
1402	n/a	while (d < 0) {
1403	n/a	if (len == 0) {
1404	n/a	samps = PyTuple_New(nchannels);
1405	n/a	if (samps == NULL)
1406	n/a	goto exit;
1407	n/a	for (chan = 0; chan < nchannels; chan++)
1408	n/a	PyTuple_SetItem(samps, chan,
1409	n/a	Py_BuildValue("(ii)",
1410	n/a	prev_i[chan],
1411	n/a	cur_i[chan]));
1412	n/a	if (PyErr_Occurred())
1413	n/a	goto exit;
1414	n/a	/* We have checked before that the length
1415	n/a	* of the string fits into int. */
1416	n/a	len = (Py_ssize_t)(ncp - PyBytes_AsString(str));
1417	n/a	rv = PyBytes_FromStringAndSize
1418	n/a	(PyBytes_AsString(str), len);
1419	n/a	Py_DECREF(str);
1420	n/a	str = rv;
1421	n/a	if (str == NULL)
1422	n/a	goto exit;
1423	n/a	rv = Py_BuildValue("(O(iO))", str, d, samps);
1424	n/a	Py_DECREF(samps);
1425	n/a	Py_DECREF(str);
1426	n/a	goto exit; /* return rv */
1427	n/a	}
1428	n/a	for (chan = 0; chan < nchannels; chan++) {
1429	n/a	prev_i[chan] = cur_i[chan];
1430	n/a	cur_i[chan] = GETSAMPLE32(width, cp, 0);
1431	n/a	cp += width;
1432	n/a	/* implements a simple digital filter */
1433	n/a	cur_i[chan] = (int)(
1434	n/a	((double)weightA * (double)cur_i[chan] +
1435	n/a	(double)weightB * (double)prev_i[chan]) /
1436	n/a	((double)weightA + (double)weightB));
1437	n/a	}
1438	n/a	len--;
1439	n/a	d += outrate;
1440	n/a	}
1441	n/a	while (d >= 0) {
1442	n/a	for (chan = 0; chan < nchannels; chan++) {
1443	n/a	cur_o = (int)(((double)prev_i[chan] * (double)d +
1444	n/a	(double)cur_i[chan] * (double)(outrate - d)) /
1445	n/a	(double)outrate);
1446	n/a	SETSAMPLE32(width, ncp, 0, cur_o);
1447	n/a	ncp += width;
1448	n/a	}
1449	n/a	d -= inrate;
1450	n/a	}
1451	n/a	}
1452	n/a	exit:
1453	n/a	PyMem_Free(prev_i);
1454	n/a	PyMem_Free(cur_i);
1455	n/a	return rv;
1456	n/a	}
1457	n/a
1458	n/a	/*[clinic input]
1459	n/a	audioop.lin2ulaw
1460	n/a
1461	n/a	fragment: Py_buffer
1462	n/a	width: int
1463	n/a	/
1464	n/a
1465	n/a	Convert samples in the audio fragment to u-LAW encoding.
1466	n/a	[clinic start generated code]*/
1467	n/a
1468	n/a	static PyObject *
1469	n/a	audioop_lin2ulaw_impl(PyObject module, Py_buffer fragment, int width)
1470	n/a	/[clinic end generated code: output=14fb62b16fe8ea8e input=2450d1b870b6bac2]/
1471	n/a	{
1472	n/a	unsigned char *ncp;
1473	n/a	Py_ssize_t i;
1474	n/a	PyObject *rv;
1475	n/a
1476	n/a	if (!audioop_check_parameters(fragment->len, width))
1477	n/a	return NULL;
1478	n/a
1479	n/a	rv = PyBytes_FromStringAndSize(NULL, fragment->len/width);
1480	n/a	if (rv == NULL)
1481	n/a	return NULL;
1482	n/a	ncp = (unsigned char *)PyBytes_AsString(rv);
1483	n/a
1484	n/a	for (i = 0; i < fragment->len; i += width) {
1485	n/a	int val = GETSAMPLE32(width, fragment->buf, i);
1486	n/a	*ncp++ = st_14linear2ulaw(val >> 18);
1487	n/a	}
1488	n/a	return rv;
1489	n/a	}
1490	n/a
1491	n/a	/*[clinic input]
1492	n/a	audioop.ulaw2lin
1493	n/a
1494	n/a	fragment: Py_buffer
1495	n/a	width: int
1496	n/a	/
1497	n/a
1498	n/a	Convert sound fragments in u-LAW encoding to linearly encoded sound fragments.
1499	n/a	[clinic start generated code]*/
1500	n/a
1501	n/a	static PyObject *
1502	n/a	audioop_ulaw2lin_impl(PyObject module, Py_buffer fragment, int width)
1503	n/a	/[clinic end generated code: output=378356b047521ba2 input=45d53ddce5be7d06]/
1504	n/a	{
1505	n/a	unsigned char *cp;
1506	n/a	signed char *ncp;
1507	n/a	Py_ssize_t i;
1508	n/a	PyObject *rv;
1509	n/a
1510	n/a	if (!audioop_check_size(width))
1511	n/a	return NULL;
1512	n/a
1513	n/a	if (fragment->len > PY_SSIZE_T_MAX/width) {
1514	n/a	PyErr_SetString(PyExc_MemoryError,
1515	n/a	"not enough memory for output buffer");
1516	n/a	return NULL;
1517	n/a	}
1518	n/a	rv = PyBytes_FromStringAndSize(NULL, fragment->len*width);
1519	n/a	if (rv == NULL)
1520	n/a	return NULL;
1521	n/a	ncp = (signed char *)PyBytes_AsString(rv);
1522	n/a
1523	n/a	cp = fragment->buf;
1524	n/a	for (i = 0; i < fragment->len*width; i += width) {
1525	n/a	int val = st_ulaw2linear16(*cp++) << 16;
1526	n/a	SETSAMPLE32(width, ncp, i, val);
1527	n/a	}
1528	n/a	return rv;
1529	n/a	}
1530	n/a
1531	n/a	/*[clinic input]
1532	n/a	audioop.lin2alaw
1533	n/a
1534	n/a	fragment: Py_buffer
1535	n/a	width: int
1536	n/a	/
1537	n/a
1538	n/a	Convert samples in the audio fragment to a-LAW encoding.
1539	n/a	[clinic start generated code]*/
1540	n/a
1541	n/a	static PyObject *
1542	n/a	audioop_lin2alaw_impl(PyObject module, Py_buffer fragment, int width)
1543	n/a	/[clinic end generated code: output=d076f130121a82f0 input=ffb1ef8bb39da945]/
1544	n/a	{
1545	n/a	unsigned char *ncp;
1546	n/a	Py_ssize_t i;
1547	n/a	PyObject *rv;
1548	n/a
1549	n/a	if (!audioop_check_parameters(fragment->len, width))
1550	n/a	return NULL;
1551	n/a
1552	n/a	rv = PyBytes_FromStringAndSize(NULL, fragment->len/width);
1553	n/a	if (rv == NULL)
1554	n/a	return NULL;
1555	n/a	ncp = (unsigned char *)PyBytes_AsString(rv);
1556	n/a
1557	n/a	for (i = 0; i < fragment->len; i += width) {
1558	n/a	int val = GETSAMPLE32(width, fragment->buf, i);
1559	n/a	*ncp++ = st_linear2alaw(val >> 19);
1560	n/a	}
1561	n/a	return rv;
1562	n/a	}
1563	n/a
1564	n/a	/*[clinic input]
1565	n/a	audioop.alaw2lin
1566	n/a
1567	n/a	fragment: Py_buffer
1568	n/a	width: int
1569	n/a	/
1570	n/a
1571	n/a	Convert sound fragments in a-LAW encoding to linearly encoded sound fragments.
1572	n/a	[clinic start generated code]*/
1573	n/a
1574	n/a	static PyObject *
1575	n/a	audioop_alaw2lin_impl(PyObject module, Py_buffer fragment, int width)
1576	n/a	/[clinic end generated code: output=85c365ec559df647 input=4140626046cd1772]/
1577	n/a	{
1578	n/a	unsigned char *cp;
1579	n/a	signed char *ncp;
1580	n/a	Py_ssize_t i;
1581	n/a	int val;
1582	n/a	PyObject *rv;
1583	n/a
1584	n/a	if (!audioop_check_size(width))
1585	n/a	return NULL;
1586	n/a
1587	n/a	if (fragment->len > PY_SSIZE_T_MAX/width) {
1588	n/a	PyErr_SetString(PyExc_MemoryError,
1589	n/a	"not enough memory for output buffer");
1590	n/a	return NULL;
1591	n/a	}
1592	n/a	rv = PyBytes_FromStringAndSize(NULL, fragment->len*width);
1593	n/a	if (rv == NULL)
1594	n/a	return NULL;
1595	n/a	ncp = (signed char *)PyBytes_AsString(rv);
1596	n/a	cp = fragment->buf;
1597	n/a
1598	n/a	for (i = 0; i < fragment->len*width; i += width) {
1599	n/a	val = st_alaw2linear16(*cp++) << 16;
1600	n/a	SETSAMPLE32(width, ncp, i, val);
1601	n/a	}
1602	n/a	return rv;
1603	n/a	}
1604	n/a
1605	n/a	/*[clinic input]
1606	n/a	audioop.lin2adpcm
1607	n/a
1608	n/a	fragment: Py_buffer
1609	n/a	width: int
1610	n/a	state: object
1611	n/a	/
1612	n/a
1613	n/a	Convert samples to 4 bit Intel/DVI ADPCM encoding.
1614	n/a	[clinic start generated code]*/
1615	n/a
1616	n/a	static PyObject *
1617	n/a	audioop_lin2adpcm_impl(PyObject module, Py_buffer fragment, int width,
1618	n/a	PyObject *state)
1619	n/a	/[clinic end generated code: output=cc19f159f16c6793 input=12919d549b90c90a]/
1620	n/a	{
1621	n/a	signed char *ncp;
1622	n/a	Py_ssize_t i;
1623	n/a	int step, valpred, delta,
1624	n/a	index, sign, vpdiff, diff;
1625	n/a	PyObject rv = NULL, str;
1626	n/a	int outputbuffer = 0, bufferstep;
1627	n/a
1628	n/a	if (!audioop_check_parameters(fragment->len, width))
1629	n/a	return NULL;
1630	n/a
1631	n/a	/* Decode state, should have (value, step) */
1632	n/a	if ( state == Py_None ) {
1633	n/a	/* First time, it seems. Set defaults */
1634	n/a	valpred = 0;
1635	n/a	index = 0;
1636	n/a	}
1637	n/a	else if (!PyTuple_Check(state)) {
1638	n/a	PyErr_SetString(PyExc_TypeError, "state must be a tuple or None");
1639	n/a	return NULL;
1640	n/a	}
1641	n/a	else if (!PyArg_ParseTuple(state, "ii", &valpred, &index)) {
1642	n/a	return NULL;
1643	n/a	}
1644	n/a	else if (valpred >= 0x8000 \|\| valpred < -0x8000 \|\|
1645	n/a	(size_t)index >= Py_ARRAY_LENGTH(stepsizeTable)) {
1646	n/a	PyErr_SetString(PyExc_ValueError, "bad state");
1647	n/a	return NULL;
1648	n/a	}
1649	n/a
1650	n/a	str = PyBytes_FromStringAndSize(NULL, fragment->len/(width*2));
1651	n/a	if (str == NULL)
1652	n/a	return NULL;
1653	n/a	ncp = (signed char *)PyBytes_AsString(str);
1654	n/a
1655	n/a	step = stepsizeTable[index];
1656	n/a	bufferstep = 1;
1657	n/a
1658	n/a	for (i = 0; i < fragment->len; i += width) {
1659	n/a	int val = GETSAMPLE32(width, fragment->buf, i) >> 16;
1660	n/a
1661	n/a	/* Step 1 - compute difference with previous value */
1662	n/a	if (val < valpred) {
1663	n/a	diff = valpred - val;
1664	n/a	sign = 8;
1665	n/a	}
1666	n/a	else {
1667	n/a	diff = val - valpred;
1668	n/a	sign = 0;
1669	n/a	}
1670	n/a
1671	n/a	/* Step 2 - Divide and clamp */
1672	n/a	/* Note:
1673	n/a	** This code approximately computes:
1674	n/a	** delta = diff*4/step;
1675	n/a	** vpdiff = (delta+0.5)*step/4;
1676	n/a	** but in shift step bits are dropped. The net result of this
1677	n/a	** is that even if you have fast mul/div hardware you cannot
1678	n/a	** put it to good use since the fixup would be too expensive.
1679	n/a	*/
1680	n/a	delta = 0;
1681	n/a	vpdiff = (step >> 3);
1682	n/a
1683	n/a	if ( diff >= step ) {
1684	n/a	delta = 4;
1685	n/a	diff -= step;
1686	n/a	vpdiff += step;
1687	n/a	}
1688	n/a	step >>= 1;
1689	n/a	if ( diff >= step ) {
1690	n/a	delta \|= 2;
1691	n/a	diff -= step;
1692	n/a	vpdiff += step;
1693	n/a	}
1694	n/a	step >>= 1;
1695	n/a	if ( diff >= step ) {
1696	n/a	delta \|= 1;
1697	n/a	vpdiff += step;
1698	n/a	}
1699	n/a
1700	n/a	/* Step 3 - Update previous value */
1701	n/a	if ( sign )
1702	n/a	valpred -= vpdiff;
1703	n/a	else
1704	n/a	valpred += vpdiff;
1705	n/a
1706	n/a	/* Step 4 - Clamp previous value to 16 bits */
1707	n/a	if ( valpred > 32767 )
1708	n/a	valpred = 32767;
1709	n/a	else if ( valpred < -32768 )
1710	n/a	valpred = -32768;
1711	n/a
1712	n/a	/* Step 5 - Assemble value, update index and step values */
1713	n/a	delta \|= sign;
1714	n/a
1715	n/a	index += indexTable[delta];
1716	n/a	if ( index < 0 ) index = 0;
1717	n/a	if ( index > 88 ) index = 88;
1718	n/a	step = stepsizeTable[index];
1719	n/a
1720	n/a	/* Step 6 - Output value */
1721	n/a	if ( bufferstep ) {
1722	n/a	outputbuffer = (delta << 4) & 0xf0;
1723	n/a	} else {
1724	n/a	*ncp++ = (delta & 0x0f) \| outputbuffer;
1725	n/a	}
1726	n/a	bufferstep = !bufferstep;
1727	n/a	}
1728	n/a	rv = Py_BuildValue("(O(ii))", str, valpred, index);
1729	n/a	Py_DECREF(str);
1730	n/a	return rv;
1731	n/a	}
1732	n/a
1733	n/a	/*[clinic input]
1734	n/a	audioop.adpcm2lin
1735	n/a
1736	n/a	fragment: Py_buffer
1737	n/a	width: int
1738	n/a	state: object
1739	n/a	/
1740	n/a
1741	n/a	Decode an Intel/DVI ADPCM coded fragment to a linear fragment.
1742	n/a	[clinic start generated code]*/
1743	n/a
1744	n/a	static PyObject *
1745	n/a	audioop_adpcm2lin_impl(PyObject module, Py_buffer fragment, int width,
1746	n/a	PyObject *state)
1747	n/a	/[clinic end generated code: output=3440ea105acb3456 input=f5221144f5ca9ef0]/
1748	n/a	{
1749	n/a	signed char *cp;
1750	n/a	signed char *ncp;
1751	n/a	Py_ssize_t i, outlen;
1752	n/a	int valpred, step, delta, index, sign, vpdiff;
1753	n/a	PyObject rv, str;
1754	n/a	int inputbuffer = 0, bufferstep;
1755	n/a
1756	n/a	if (!audioop_check_size(width))
1757	n/a	return NULL;
1758	n/a
1759	n/a	/* Decode state, should have (value, step) */
1760	n/a	if ( state == Py_None ) {
1761	n/a	/* First time, it seems. Set defaults */
1762	n/a	valpred = 0;
1763	n/a	index = 0;
1764	n/a	}
1765	n/a	else if (!PyTuple_Check(state)) {
1766	n/a	PyErr_SetString(PyExc_TypeError, "state must be a tuple or None");
1767	n/a	return NULL;
1768	n/a	}
1769	n/a	else if (!PyArg_ParseTuple(state, "ii", &valpred, &index)) {
1770	n/a	return NULL;
1771	n/a	}
1772	n/a	else if (valpred >= 0x8000 \|\| valpred < -0x8000 \|\|
1773	n/a	(size_t)index >= Py_ARRAY_LENGTH(stepsizeTable)) {
1774	n/a	PyErr_SetString(PyExc_ValueError, "bad state");
1775	n/a	return NULL;
1776	n/a	}
1777	n/a
1778	n/a	if (fragment->len > (PY_SSIZE_T_MAX/2)/width) {
1779	n/a	PyErr_SetString(PyExc_MemoryError,
1780	n/a	"not enough memory for output buffer");
1781	n/a	return NULL;
1782	n/a	}
1783	n/a	outlen = fragment->lenwidth2;
1784	n/a	str = PyBytes_FromStringAndSize(NULL, outlen);
1785	n/a	if (str == NULL)
1786	n/a	return NULL;
1787	n/a	ncp = (signed char *)PyBytes_AsString(str);
1788	n/a	cp = fragment->buf;
1789	n/a
1790	n/a	step = stepsizeTable[index];
1791	n/a	bufferstep = 0;
1792	n/a
1793	n/a	for (i = 0; i < outlen; i += width) {
1794	n/a	/* Step 1 - get the delta value and compute next index */
1795	n/a	if ( bufferstep ) {
1796	n/a	delta = inputbuffer & 0xf;
1797	n/a	} else {
1798	n/a	inputbuffer = *cp++;
1799	n/a	delta = (inputbuffer >> 4) & 0xf;
1800	n/a	}
1801	n/a
1802	n/a	bufferstep = !bufferstep;
1803	n/a
1804	n/a	/* Step 2 - Find new index value (for later) */
1805	n/a	index += indexTable[delta];
1806	n/a	if ( index < 0 ) index = 0;
1807	n/a	if ( index > 88 ) index = 88;
1808	n/a
1809	n/a	/* Step 3 - Separate sign and magnitude */
1810	n/a	sign = delta & 8;
1811	n/a	delta = delta & 7;
1812	n/a
1813	n/a	/* Step 4 - Compute difference and new predicted value */
1814	n/a	/*
1815	n/a	** Computes 'vpdiff = (delta+0.5)*step/4', but see comment
1816	n/a	** in adpcm_coder.
1817	n/a	*/
1818	n/a	vpdiff = step >> 3;
1819	n/a	if ( delta & 4 ) vpdiff += step;
1820	n/a	if ( delta & 2 ) vpdiff += step>>1;
1821	n/a	if ( delta & 1 ) vpdiff += step>>2;
1822	n/a
1823	n/a	if ( sign )
1824	n/a	valpred -= vpdiff;
1825	n/a	else
1826	n/a	valpred += vpdiff;
1827	n/a
1828	n/a	/* Step 5 - clamp output value */
1829	n/a	if ( valpred > 32767 )
1830	n/a	valpred = 32767;
1831	n/a	else if ( valpred < -32768 )
1832	n/a	valpred = -32768;
1833	n/a
1834	n/a	/* Step 6 - Update step value */
1835	n/a	step = stepsizeTable[index];
1836	n/a
1837	n/a	/* Step 6 - Output value */
1838	n/a	SETSAMPLE32(width, ncp, i, valpred << 16);
1839	n/a	}
1840	n/a
1841	n/a	rv = Py_BuildValue("(O(ii))", str, valpred, index);
1842	n/a	Py_DECREF(str);
1843	n/a	return rv;
1844	n/a	}
1845	n/a
1846	n/a	#include "clinic/audioop.c.h"
1847	n/a
1848	n/a	static PyMethodDef audioop_methods[] = {
1849	n/a	AUDIOOP_MAX_METHODDEF
1850	n/a	AUDIOOP_MINMAX_METHODDEF
1851	n/a	AUDIOOP_AVG_METHODDEF
1852	n/a	AUDIOOP_MAXPP_METHODDEF
1853	n/a	AUDIOOP_AVGPP_METHODDEF
1854	n/a	AUDIOOP_RMS_METHODDEF
1855	n/a	AUDIOOP_FINDFIT_METHODDEF
1856	n/a	AUDIOOP_FINDMAX_METHODDEF
1857	n/a	AUDIOOP_FINDFACTOR_METHODDEF
1858	n/a	AUDIOOP_CROSS_METHODDEF
1859	n/a	AUDIOOP_MUL_METHODDEF
1860	n/a	AUDIOOP_ADD_METHODDEF
1861	n/a	AUDIOOP_BIAS_METHODDEF
1862	n/a	AUDIOOP_ULAW2LIN_METHODDEF
1863	n/a	AUDIOOP_LIN2ULAW_METHODDEF
1864	n/a	AUDIOOP_ALAW2LIN_METHODDEF
1865	n/a	AUDIOOP_LIN2ALAW_METHODDEF
1866	n/a	AUDIOOP_LIN2LIN_METHODDEF
1867	n/a	AUDIOOP_ADPCM2LIN_METHODDEF
1868	n/a	AUDIOOP_LIN2ADPCM_METHODDEF
1869	n/a	AUDIOOP_TOMONO_METHODDEF
1870	n/a	AUDIOOP_TOSTEREO_METHODDEF
1871	n/a	AUDIOOP_GETSAMPLE_METHODDEF
1872	n/a	AUDIOOP_REVERSE_METHODDEF
1873	n/a	AUDIOOP_BYTESWAP_METHODDEF
1874	n/a	AUDIOOP_RATECV_METHODDEF
1875	n/a	{ 0, 0 }
1876	n/a	};
1877	n/a
1878	n/a
1879	n/a	static struct PyModuleDef audioopmodule = {
1880	n/a	PyModuleDef_HEAD_INIT,
1881	n/a	"audioop",
1882	n/a	NULL,
1883	n/a	-1,
1884	n/a	audioop_methods,
1885	n/a	NULL,
1886	n/a	NULL,
1887	n/a	NULL,
1888	n/a	NULL
1889	n/a	};
1890	n/a
1891	n/a	PyMODINIT_FUNC
1892	n/a	PyInit_audioop(void)
1893	n/a	{
1894	n/a	PyObject m, d;
1895	n/a	m = PyModule_Create(&audioopmodule);
1896	n/a	if (m == NULL)
1897	n/a	return NULL;
1898	n/a	d = PyModule_GetDict(m);
1899	n/a	if (d == NULL)
1900	n/a	return NULL;
1901	n/a	AudioopError = PyErr_NewException("audioop.error", NULL, NULL);
1902	n/a	if (AudioopError != NULL)
1903	n/a	PyDict_SetItemString(d,"error",AudioopError);
1904	n/a	return m;
1905	n/a	}