1 | |
2 | /* audioopmodule - Module to detect peak values in arrays */ |
3 | |
4 | #define PY_SSIZE_T_CLEAN |
5 | |
6 | #include "Python.h" |
7 | |
8 | static const int maxvals[] = {0, 0x7F, 0x7FFF, 0x7FFFFF, 0x7FFFFFFF}; |
9 | /* -1 trick is needed on Windows to support -0x80000000 without a warning */ |
10 | static const int minvals[] = {0, -0x80, -0x8000, -0x800000, -0x7FFFFFFF-1}; |
11 | static const unsigned int masks[] = {0, 0xFF, 0xFFFF, 0xFFFFFF, 0xFFFFFFFF}; |
12 | |
13 | static int |
14 | fbound(double val, double minval, double maxval) |
15 | { |
16 | if (val > maxval) { |
17 | val = maxval; |
18 | } |
19 | else if (val < minval + 1.0) { |
20 | val = minval; |
21 | } |
22 | |
23 | /* Round towards minus infinity (-inf) */ |
24 | val = floor(val); |
25 | |
26 | /* Cast double to integer: round towards zero */ |
27 | return (int)val; |
28 | } |
29 | |
30 | |
31 | /* Code shamelessly stolen from sox, 12.17.7, g711.c |
32 | ** (c) Craig Reese, Joe Campbell and Jeff Poskanzer 1989 */ |
33 | |
34 | /* From g711.c: |
35 | * |
36 | * December 30, 1994: |
37 | * Functions linear2alaw, linear2ulaw have been updated to correctly |
38 | * convert unquantized 16 bit values. |
39 | * Tables for direct u- to A-law and A- to u-law conversions have been |
40 | * corrected. |
41 | * Borge Lindberg, Center for PersonKommunikation, Aalborg University. |
42 | * [email protected] |
43 | * |
44 | */ |
45 | #define BIAS 0x84 /* define the add-in bias for 16 bit samples */ |
46 | #define CLIP 32635 |
47 | #define SIGN_BIT (0x80) /* Sign bit for an A-law byte. */ |
48 | #define QUANT_MASK (0xf) /* Quantization field mask. */ |
49 | #define SEG_SHIFT (4) /* Left shift for segment number. */ |
50 | #define SEG_MASK (0x70) /* Segment field mask. */ |
51 | |
52 | static const int16_t seg_aend[8] = { |
53 | 0x1F, 0x3F, 0x7F, 0xFF, 0x1FF, 0x3FF, 0x7FF, 0xFFF |
54 | }; |
55 | static const int16_t seg_uend[8] = { |
56 | 0x3F, 0x7F, 0xFF, 0x1FF, 0x3FF, 0x7FF, 0xFFF, 0x1FFF |
57 | }; |
58 | |
59 | static int16_t |
60 | search(int16_t val, const int16_t *table, int size) |
61 | { |
62 | int i; |
63 | |
64 | for (i = 0; i < size; i++) { |
65 | if (val <= *table++) |
66 | return (i); |
67 | } |
68 | return (size); |
69 | } |
70 | #define st_ulaw2linear16(uc) (_st_ulaw2linear16[uc]) |
71 | #define st_alaw2linear16(uc) (_st_alaw2linear16[uc]) |
72 | |
73 | static const int16_t _st_ulaw2linear16[256] = { |
74 | -32124, -31100, -30076, -29052, -28028, -27004, -25980, |
75 | -24956, -23932, -22908, -21884, -20860, -19836, -18812, |
76 | -17788, -16764, -15996, -15484, -14972, -14460, -13948, |
77 | -13436, -12924, -12412, -11900, -11388, -10876, -10364, |
78 | -9852, -9340, -8828, -8316, -7932, -7676, -7420, |
79 | -7164, -6908, -6652, -6396, -6140, -5884, -5628, |
80 | -5372, -5116, -4860, -4604, -4348, -4092, -3900, |
81 | -3772, -3644, -3516, -3388, -3260, -3132, -3004, |
82 | -2876, -2748, -2620, -2492, -2364, -2236, -2108, |
83 | -1980, -1884, -1820, -1756, -1692, -1628, -1564, |
84 | -1500, -1436, -1372, -1308, -1244, -1180, -1116, |
85 | -1052, -988, -924, -876, -844, -812, -780, |
86 | -748, -716, -684, -652, -620, -588, -556, |
87 | -524, -492, -460, -428, -396, -372, -356, |
88 | -340, -324, -308, -292, -276, -260, -244, |
89 | -228, -212, -196, -180, -164, -148, -132, |
90 | -120, -112, -104, -96, -88, -80, -72, |
91 | -64, -56, -48, -40, -32, -24, -16, |
92 | -8, 0, 32124, 31100, 30076, 29052, 28028, |
93 | 27004, 25980, 24956, 23932, 22908, 21884, 20860, |
94 | 19836, 18812, 17788, 16764, 15996, 15484, 14972, |
95 | 14460, 13948, 13436, 12924, 12412, 11900, 11388, |
96 | 10876, 10364, 9852, 9340, 8828, 8316, 7932, |
97 | 7676, 7420, 7164, 6908, 6652, 6396, 6140, |
98 | 5884, 5628, 5372, 5116, 4860, 4604, 4348, |
99 | 4092, 3900, 3772, 3644, 3516, 3388, 3260, |
100 | 3132, 3004, 2876, 2748, 2620, 2492, 2364, |
101 | 2236, 2108, 1980, 1884, 1820, 1756, 1692, |
102 | 1628, 1564, 1500, 1436, 1372, 1308, 1244, |
103 | 1180, 1116, 1052, 988, 924, 876, 844, |
104 | 812, 780, 748, 716, 684, 652, 620, |
105 | 588, 556, 524, 492, 460, 428, 396, |
106 | 372, 356, 340, 324, 308, 292, 276, |
107 | 260, 244, 228, 212, 196, 180, 164, |
108 | 148, 132, 120, 112, 104, 96, 88, |
109 | 80, 72, 64, 56, 48, 40, 32, |
110 | 24, 16, 8, 0 |
111 | }; |
112 | |
113 | /* |
114 | * linear2ulaw() accepts a 14-bit signed integer and encodes it as u-law data |
115 | * stored in an unsigned char. This function should only be called with |
116 | * the data shifted such that it only contains information in the lower |
117 | * 14-bits. |
118 | * |
119 | * In order to simplify the encoding process, the original linear magnitude |
120 | * is biased by adding 33 which shifts the encoding range from (0 - 8158) to |
121 | * (33 - 8191). The result can be seen in the following encoding table: |
122 | * |
123 | * Biased Linear Input Code Compressed Code |
124 | * ------------------------ --------------- |
125 | * 00000001wxyza 000wxyz |
126 | * 0000001wxyzab 001wxyz |
127 | * 000001wxyzabc 010wxyz |
128 | * 00001wxyzabcd 011wxyz |
129 | * 0001wxyzabcde 100wxyz |
130 | * 001wxyzabcdef 101wxyz |
131 | * 01wxyzabcdefg 110wxyz |
132 | * 1wxyzabcdefgh 111wxyz |
133 | * |
134 | * Each biased linear code has a leading 1 which identifies the segment |
135 | * number. The value of the segment number is equal to 7 minus the number |
136 | * of leading 0's. The quantization interval is directly available as the |
137 | * four bits wxyz. * The trailing bits (a - h) are ignored. |
138 | * |
139 | * Ordinarily the complement of the resulting code word is used for |
140 | * transmission, and so the code word is complemented before it is returned. |
141 | * |
142 | * For further information see John C. Bellamy's Digital Telephony, 1982, |
143 | * John Wiley & Sons, pps 98-111 and 472-476. |
144 | */ |
145 | static unsigned char |
146 | st_14linear2ulaw(int16_t pcm_val) /* 2's complement (14-bit range) */ |
147 | { |
148 | int16_t mask; |
149 | int16_t seg; |
150 | unsigned char uval; |
151 | |
152 | /* u-law inverts all bits */ |
153 | /* Get the sign and the magnitude of the value. */ |
154 | if (pcm_val < 0) { |
155 | pcm_val = -pcm_val; |
156 | mask = 0x7F; |
157 | } else { |
158 | mask = 0xFF; |
159 | } |
160 | if ( pcm_val > CLIP ) pcm_val = CLIP; /* clip the magnitude */ |
161 | pcm_val += (BIAS >> 2); |
162 | |
163 | /* Convert the scaled magnitude to segment number. */ |
164 | seg = search(pcm_val, seg_uend, 8); |
165 | |
166 | /* |
167 | * Combine the sign, segment, quantization bits; |
168 | * and complement the code word. |
169 | */ |
170 | if (seg >= 8) /* out of range, return maximum value. */ |
171 | return (unsigned char) (0x7F ^ mask); |
172 | else { |
173 | uval = (unsigned char) (seg << 4) | ((pcm_val >> (seg + 1)) & 0xF); |
174 | return (uval ^ mask); |
175 | } |
176 | |
177 | } |
178 | |
179 | static const int16_t _st_alaw2linear16[256] = { |
180 | -5504, -5248, -6016, -5760, -4480, -4224, -4992, |
181 | -4736, -7552, -7296, -8064, -7808, -6528, -6272, |
182 | -7040, -6784, -2752, -2624, -3008, -2880, -2240, |
183 | -2112, -2496, -2368, -3776, -3648, -4032, -3904, |
184 | -3264, -3136, -3520, -3392, -22016, -20992, -24064, |
185 | -23040, -17920, -16896, -19968, -18944, -30208, -29184, |
186 | -32256, -31232, -26112, -25088, -28160, -27136, -11008, |
187 | -10496, -12032, -11520, -8960, -8448, -9984, -9472, |
188 | -15104, -14592, -16128, -15616, -13056, -12544, -14080, |
189 | -13568, -344, -328, -376, -360, -280, -264, |
190 | -312, -296, -472, -456, -504, -488, -408, |
191 | -392, -440, -424, -88, -72, -120, -104, |
192 | -24, -8, -56, -40, -216, -200, -248, |
193 | -232, -152, -136, -184, -168, -1376, -1312, |
194 | -1504, -1440, -1120, -1056, -1248, -1184, -1888, |
195 | -1824, -2016, -1952, -1632, -1568, -1760, -1696, |
196 | -688, -656, -752, -720, -560, -528, -624, |
197 | -592, -944, -912, -1008, -976, -816, -784, |
198 | -880, -848, 5504, 5248, 6016, 5760, 4480, |
199 | 4224, 4992, 4736, 7552, 7296, 8064, 7808, |
200 | 6528, 6272, 7040, 6784, 2752, 2624, 3008, |
201 | 2880, 2240, 2112, 2496, 2368, 3776, 3648, |
202 | 4032, 3904, 3264, 3136, 3520, 3392, 22016, |
203 | 20992, 24064, 23040, 17920, 16896, 19968, 18944, |
204 | 30208, 29184, 32256, 31232, 26112, 25088, 28160, |
205 | 27136, 11008, 10496, 12032, 11520, 8960, 8448, |
206 | 9984, 9472, 15104, 14592, 16128, 15616, 13056, |
207 | 12544, 14080, 13568, 344, 328, 376, 360, |
208 | 280, 264, 312, 296, 472, 456, 504, |
209 | 488, 408, 392, 440, 424, 88, 72, |
210 | 120, 104, 24, 8, 56, 40, 216, |
211 | 200, 248, 232, 152, 136, 184, 168, |
212 | 1376, 1312, 1504, 1440, 1120, 1056, 1248, |
213 | 1184, 1888, 1824, 2016, 1952, 1632, 1568, |
214 | 1760, 1696, 688, 656, 752, 720, 560, |
215 | 528, 624, 592, 944, 912, 1008, 976, |
216 | 816, 784, 880, 848 |
217 | }; |
218 | |
219 | /* |
220 | * linear2alaw() accepts a 13-bit signed integer and encodes it as A-law data |
221 | * stored in an unsigned char. This function should only be called with |
222 | * the data shifted such that it only contains information in the lower |
223 | * 13-bits. |
224 | * |
225 | * Linear Input Code Compressed Code |
226 | * ------------------------ --------------- |
227 | * 0000000wxyza 000wxyz |
228 | * 0000001wxyza 001wxyz |
229 | * 000001wxyzab 010wxyz |
230 | * 00001wxyzabc 011wxyz |
231 | * 0001wxyzabcd 100wxyz |
232 | * 001wxyzabcde 101wxyz |
233 | * 01wxyzabcdef 110wxyz |
234 | * 1wxyzabcdefg 111wxyz |
235 | * |
236 | * For further information see John C. Bellamy's Digital Telephony, 1982, |
237 | * John Wiley & Sons, pps 98-111 and 472-476. |
238 | */ |
239 | static unsigned char |
240 | st_linear2alaw(int16_t pcm_val) /* 2's complement (13-bit range) */ |
241 | { |
242 | int16_t mask; |
243 | int16_t seg; |
244 | unsigned char aval; |
245 | |
246 | /* A-law using even bit inversion */ |
247 | if (pcm_val >= 0) { |
248 | mask = 0xD5; /* sign (7th) bit = 1 */ |
249 | } else { |
250 | mask = 0x55; /* sign bit = 0 */ |
251 | pcm_val = -pcm_val - 1; |
252 | } |
253 | |
254 | /* Convert the scaled magnitude to segment number. */ |
255 | seg = search(pcm_val, seg_aend, 8); |
256 | |
257 | /* Combine the sign, segment, and quantization bits. */ |
258 | |
259 | if (seg >= 8) /* out of range, return maximum value. */ |
260 | return (unsigned char) (0x7F ^ mask); |
261 | else { |
262 | aval = (unsigned char) seg << SEG_SHIFT; |
263 | if (seg < 2) |
264 | aval |= (pcm_val >> 1) & QUANT_MASK; |
265 | else |
266 | aval |= (pcm_val >> seg) & QUANT_MASK; |
267 | return (aval ^ mask); |
268 | } |
269 | } |
270 | /* End of code taken from sox */ |
271 | |
272 | /* Intel ADPCM step variation table */ |
273 | static const int indexTable[16] = { |
274 | -1, -1, -1, -1, 2, 4, 6, 8, |
275 | -1, -1, -1, -1, 2, 4, 6, 8, |
276 | }; |
277 | |
278 | static const int stepsizeTable[89] = { |
279 | 7, 8, 9, 10, 11, 12, 13, 14, 16, 17, |
280 | 19, 21, 23, 25, 28, 31, 34, 37, 41, 45, |
281 | 50, 55, 60, 66, 73, 80, 88, 97, 107, 118, |
282 | 130, 143, 157, 173, 190, 209, 230, 253, 279, 307, |
283 | 337, 371, 408, 449, 494, 544, 598, 658, 724, 796, |
284 | 876, 963, 1060, 1166, 1282, 1411, 1552, 1707, 1878, 2066, |
285 | 2272, 2499, 2749, 3024, 3327, 3660, 4026, 4428, 4871, 5358, |
286 | 5894, 6484, 7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899, |
287 | 15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767 |
288 | }; |
289 | |
290 | #define GETINTX(T, cp, i) (*(T *)((unsigned char *)(cp) + (i))) |
291 | #define SETINTX(T, cp, i, val) do { \ |
292 | *(T *)((unsigned char *)(cp) + (i)) = (T)(val); \ |
293 | } while (0) |
294 | |
295 | |
296 | #define GETINT8(cp, i) GETINTX(signed char, (cp), (i)) |
297 | #define GETINT16(cp, i) GETINTX(int16_t, (cp), (i)) |
298 | #define GETINT32(cp, i) GETINTX(int32_t, (cp), (i)) |
299 | |
300 | #if WORDS_BIGENDIAN |
301 | #define GETINT24(cp, i) ( \ |
302 | ((unsigned char *)(cp) + (i))[2] + \ |
303 | (((unsigned char *)(cp) + (i))[1] << 8) + \ |
304 | (((signed char *)(cp) + (i))[0] << 16) ) |
305 | #else |
306 | #define GETINT24(cp, i) ( \ |
307 | ((unsigned char *)(cp) + (i))[0] + \ |
308 | (((unsigned char *)(cp) + (i))[1] << 8) + \ |
309 | (((signed char *)(cp) + (i))[2] << 16) ) |
310 | #endif |
311 | |
312 | |
313 | #define SETINT8(cp, i, val) SETINTX(signed char, (cp), (i), (val)) |
314 | #define SETINT16(cp, i, val) SETINTX(int16_t, (cp), (i), (val)) |
315 | #define SETINT32(cp, i, val) SETINTX(int32_t, (cp), (i), (val)) |
316 | |
317 | #if WORDS_BIGENDIAN |
318 | #define SETINT24(cp, i, val) do { \ |
319 | ((unsigned char *)(cp) + (i))[2] = (int)(val); \ |
320 | ((unsigned char *)(cp) + (i))[1] = (int)(val) >> 8; \ |
321 | ((signed char *)(cp) + (i))[0] = (int)(val) >> 16; \ |
322 | } while (0) |
323 | #else |
324 | #define SETINT24(cp, i, val) do { \ |
325 | ((unsigned char *)(cp) + (i))[0] = (int)(val); \ |
326 | ((unsigned char *)(cp) + (i))[1] = (int)(val) >> 8; \ |
327 | ((signed char *)(cp) + (i))[2] = (int)(val) >> 16; \ |
328 | } while (0) |
329 | #endif |
330 | |
331 | |
332 | #define GETRAWSAMPLE(size, cp, i) ( \ |
333 | (size == 1) ? (int)GETINT8((cp), (i)) : \ |
334 | (size == 2) ? (int)GETINT16((cp), (i)) : \ |
335 | (size == 3) ? (int)GETINT24((cp), (i)) : \ |
336 | (int)GETINT32((cp), (i))) |
337 | |
338 | #define SETRAWSAMPLE(size, cp, i, val) do { \ |
339 | if (size == 1) \ |
340 | SETINT8((cp), (i), (val)); \ |
341 | else if (size == 2) \ |
342 | SETINT16((cp), (i), (val)); \ |
343 | else if (size == 3) \ |
344 | SETINT24((cp), (i), (val)); \ |
345 | else \ |
346 | SETINT32((cp), (i), (val)); \ |
347 | } while(0) |
348 | |
349 | |
350 | #define GETSAMPLE32(size, cp, i) ( \ |
351 | (size == 1) ? (int)GETINT8((cp), (i)) << 24 : \ |
352 | (size == 2) ? (int)GETINT16((cp), (i)) << 16 : \ |
353 | (size == 3) ? (int)GETINT24((cp), (i)) << 8 : \ |
354 | (int)GETINT32((cp), (i))) |
355 | |
356 | #define SETSAMPLE32(size, cp, i, val) do { \ |
357 | if (size == 1) \ |
358 | SETINT8((cp), (i), (val) >> 24); \ |
359 | else if (size == 2) \ |
360 | SETINT16((cp), (i), (val) >> 16); \ |
361 | else if (size == 3) \ |
362 | SETINT24((cp), (i), (val) >> 8); \ |
363 | else \ |
364 | SETINT32((cp), (i), (val)); \ |
365 | } while(0) |
366 | |
367 | static PyModuleDef audioopmodule; |
368 | |
369 | typedef struct { |
370 | PyObject *AudioopError; |
371 | } audioop_state; |
372 | |
373 | static inline audioop_state * |
374 | get_audioop_state(PyObject *module) |
375 | { |
376 | void *state = PyModule_GetState(module); |
377 | assert(state != NULL); |
378 | return (audioop_state *)state; |
379 | } |
380 | |
381 | static int |
382 | audioop_check_size(PyObject *module, int size) |
383 | { |
384 | if (size < 1 || size > 4) { |
385 | PyErr_SetString(get_audioop_state(module)->AudioopError, |
386 | "Size should be 1, 2, 3 or 4" ); |
387 | return 0; |
388 | } |
389 | else |
390 | return 1; |
391 | } |
392 | |
393 | static int |
394 | audioop_check_parameters(PyObject *module, Py_ssize_t len, int size) |
395 | { |
396 | if (!audioop_check_size(module, size)) |
397 | return 0; |
398 | if (len % size != 0) { |
399 | PyErr_SetString(get_audioop_state(module)->AudioopError, |
400 | "not a whole number of frames" ); |
401 | return 0; |
402 | } |
403 | return 1; |
404 | } |
405 | |
406 | /*[clinic input] |
407 | module audioop |
408 | [clinic start generated code]*/ |
409 | /*[clinic end generated code: output=da39a3ee5e6b4b0d input=8fa8f6611be3591a]*/ |
410 | |
411 | /*[clinic input] |
412 | audioop.getsample |
413 | |
414 | fragment: Py_buffer |
415 | width: int |
416 | index: Py_ssize_t |
417 | / |
418 | |
419 | Return the value of sample index from the fragment. |
420 | [clinic start generated code]*/ |
421 | |
422 | static PyObject * |
423 | audioop_getsample_impl(PyObject *module, Py_buffer *fragment, int width, |
424 | Py_ssize_t index) |
425 | /*[clinic end generated code: output=8fe1b1775134f39a input=88edbe2871393549]*/ |
426 | { |
427 | int val; |
428 | |
429 | if (!audioop_check_parameters(module, fragment->len, width)) |
430 | return NULL; |
431 | if (index < 0 || index >= fragment->len/width) { |
432 | PyErr_SetString(get_audioop_state(module)->AudioopError, |
433 | "Index out of range" ); |
434 | return NULL; |
435 | } |
436 | val = GETRAWSAMPLE(width, fragment->buf, index*width); |
437 | return PyLong_FromLong(val); |
438 | } |
439 | |
440 | /*[clinic input] |
441 | audioop.max |
442 | |
443 | fragment: Py_buffer |
444 | width: int |
445 | / |
446 | |
447 | Return the maximum of the absolute value of all samples in a fragment. |
448 | [clinic start generated code]*/ |
449 | |
450 | static PyObject * |
451 | audioop_max_impl(PyObject *module, Py_buffer *fragment, int width) |
452 | /*[clinic end generated code: output=e6c5952714f1c3f0 input=32bea5ea0ac8c223]*/ |
453 | { |
454 | Py_ssize_t i; |
455 | unsigned int absval, max = 0; |
456 | |
457 | if (!audioop_check_parameters(module, fragment->len, width)) |
458 | return NULL; |
459 | for (i = 0; i < fragment->len; i += width) { |
460 | int val = GETRAWSAMPLE(width, fragment->buf, i); |
461 | /* Cast to unsigned before negating. Unsigned overflow is well- |
462 | defined, but signed overflow is not. */ |
463 | if (val < 0) absval = (unsigned int)-(int64_t)val; |
464 | else absval = val; |
465 | if (absval > max) max = absval; |
466 | } |
467 | return PyLong_FromUnsignedLong(max); |
468 | } |
469 | |
470 | /*[clinic input] |
471 | audioop.minmax |
472 | |
473 | fragment: Py_buffer |
474 | width: int |
475 | / |
476 | |
477 | Return the minimum and maximum values of all samples in the sound fragment. |
478 | [clinic start generated code]*/ |
479 | |
480 | static PyObject * |
481 | audioop_minmax_impl(PyObject *module, Py_buffer *fragment, int width) |
482 | /*[clinic end generated code: output=473fda66b15c836e input=89848e9b927a0696]*/ |
483 | { |
484 | Py_ssize_t i; |
485 | /* -1 trick below is needed on Windows to support -0x80000000 without |
486 | a warning */ |
487 | int min = 0x7fffffff, max = -0x7FFFFFFF-1; |
488 | |
489 | if (!audioop_check_parameters(module, fragment->len, width)) |
490 | return NULL; |
491 | for (i = 0; i < fragment->len; i += width) { |
492 | int val = GETRAWSAMPLE(width, fragment->buf, i); |
493 | if (val > max) max = val; |
494 | if (val < min) min = val; |
495 | } |
496 | return Py_BuildValue("(ii)" , min, max); |
497 | } |
498 | |
499 | /*[clinic input] |
500 | audioop.avg |
501 | |
502 | fragment: Py_buffer |
503 | width: int |
504 | / |
505 | |
506 | Return the average over all samples in the fragment. |
507 | [clinic start generated code]*/ |
508 | |
509 | static PyObject * |
510 | audioop_avg_impl(PyObject *module, Py_buffer *fragment, int width) |
511 | /*[clinic end generated code: output=4410a4c12c3586e6 input=1114493c7611334d]*/ |
512 | { |
513 | Py_ssize_t i; |
514 | int avg; |
515 | double sum = 0.0; |
516 | |
517 | if (!audioop_check_parameters(module, fragment->len, width)) |
518 | return NULL; |
519 | for (i = 0; i < fragment->len; i += width) |
520 | sum += GETRAWSAMPLE(width, fragment->buf, i); |
521 | if (fragment->len == 0) |
522 | avg = 0; |
523 | else |
524 | avg = (int)floor(sum / (double)(fragment->len/width)); |
525 | return PyLong_FromLong(avg); |
526 | } |
527 | |
528 | /*[clinic input] |
529 | audioop.rms |
530 | |
531 | fragment: Py_buffer |
532 | width: int |
533 | / |
534 | |
535 | Return the root-mean-square of the fragment, i.e. sqrt(sum(S_i^2)/n). |
536 | [clinic start generated code]*/ |
537 | |
538 | static PyObject * |
539 | audioop_rms_impl(PyObject *module, Py_buffer *fragment, int width) |
540 | /*[clinic end generated code: output=1e7871c826445698 input=4cc57c6c94219d78]*/ |
541 | { |
542 | Py_ssize_t i; |
543 | unsigned int res; |
544 | double sum_squares = 0.0; |
545 | |
546 | if (!audioop_check_parameters(module, fragment->len, width)) |
547 | return NULL; |
548 | for (i = 0; i < fragment->len; i += width) { |
549 | double val = GETRAWSAMPLE(width, fragment->buf, i); |
550 | sum_squares += val*val; |
551 | } |
552 | if (fragment->len == 0) |
553 | res = 0; |
554 | else |
555 | res = (unsigned int)sqrt(sum_squares / (double)(fragment->len/width)); |
556 | return PyLong_FromUnsignedLong(res); |
557 | } |
558 | |
559 | static double _sum2(const int16_t *a, const int16_t *b, Py_ssize_t len) |
560 | { |
561 | Py_ssize_t i; |
562 | double sum = 0.0; |
563 | |
564 | for( i=0; i<len; i++) { |
565 | sum = sum + (double)a[i]*(double)b[i]; |
566 | } |
567 | return sum; |
568 | } |
569 | |
570 | /* |
571 | ** Findfit tries to locate a sample within another sample. Its main use |
572 | ** is in echo-cancellation (to find the feedback of the output signal in |
573 | ** the input signal). |
574 | ** The method used is as follows: |
575 | ** |
576 | ** let R be the reference signal (length n) and A the input signal (length N) |
577 | ** with N > n, and let all sums be over i from 0 to n-1. |
578 | ** |
579 | ** Now, for each j in {0..N-n} we compute a factor fj so that -fj*R matches A |
580 | ** as good as possible, i.e. sum( (A[j+i]+fj*R[i])^2 ) is minimal. This |
581 | ** equation gives fj = sum( A[j+i]R[i] ) / sum(R[i]^2). |
582 | ** |
583 | ** Next, we compute the relative distance between the original signal and |
584 | ** the modified signal and minimize that over j: |
585 | ** vj = sum( (A[j+i]-fj*R[i])^2 ) / sum( A[j+i]^2 ) => |
586 | ** vj = ( sum(A[j+i]^2)*sum(R[i]^2) - sum(A[j+i]R[i])^2 ) / sum( A[j+i]^2 ) |
587 | ** |
588 | ** In the code variables correspond as follows: |
589 | ** cp1 A |
590 | ** cp2 R |
591 | ** len1 N |
592 | ** len2 n |
593 | ** aj_m1 A[j-1] |
594 | ** aj_lm1 A[j+n-1] |
595 | ** sum_ri_2 sum(R[i]^2) |
596 | ** sum_aij_2 sum(A[i+j]^2) |
597 | ** sum_aij_ri sum(A[i+j]R[i]) |
598 | ** |
599 | ** sum_ri is calculated once, sum_aij_2 is updated each step and sum_aij_ri |
600 | ** is completely recalculated each step. |
601 | */ |
602 | /*[clinic input] |
603 | audioop.findfit |
604 | |
605 | fragment: Py_buffer |
606 | reference: Py_buffer |
607 | / |
608 | |
609 | Try to match reference as well as possible to a portion of fragment. |
610 | [clinic start generated code]*/ |
611 | |
612 | static PyObject * |
613 | audioop_findfit_impl(PyObject *module, Py_buffer *fragment, |
614 | Py_buffer *reference) |
615 | /*[clinic end generated code: output=5752306d83cbbada input=62c305605e183c9a]*/ |
616 | { |
617 | const int16_t *cp1, *cp2; |
618 | Py_ssize_t len1, len2; |
619 | Py_ssize_t j, best_j; |
620 | double aj_m1, aj_lm1; |
621 | double sum_ri_2, sum_aij_2, sum_aij_ri, result, best_result, factor; |
622 | |
623 | if (fragment->len & 1 || reference->len & 1) { |
624 | PyErr_SetString(get_audioop_state(module)->AudioopError, |
625 | "Strings should be even-sized" ); |
626 | return NULL; |
627 | } |
628 | cp1 = (const int16_t *)fragment->buf; |
629 | len1 = fragment->len >> 1; |
630 | cp2 = (const int16_t *)reference->buf; |
631 | len2 = reference->len >> 1; |
632 | |
633 | if (len1 < len2) { |
634 | PyErr_SetString(get_audioop_state(module)->AudioopError, |
635 | "First sample should be longer" ); |
636 | return NULL; |
637 | } |
638 | sum_ri_2 = _sum2(cp2, cp2, len2); |
639 | sum_aij_2 = _sum2(cp1, cp1, len2); |
640 | sum_aij_ri = _sum2(cp1, cp2, len2); |
641 | |
642 | result = (sum_ri_2*sum_aij_2 - sum_aij_ri*sum_aij_ri) / sum_aij_2; |
643 | |
644 | best_result = result; |
645 | best_j = 0; |
646 | |
647 | for ( j=1; j<=len1-len2; j++) { |
648 | aj_m1 = (double)cp1[j-1]; |
649 | aj_lm1 = (double)cp1[j+len2-1]; |
650 | |
651 | sum_aij_2 = sum_aij_2 + aj_lm1*aj_lm1 - aj_m1*aj_m1; |
652 | sum_aij_ri = _sum2(cp1+j, cp2, len2); |
653 | |
654 | result = (sum_ri_2*sum_aij_2 - sum_aij_ri*sum_aij_ri) |
655 | / sum_aij_2; |
656 | |
657 | if ( result < best_result ) { |
658 | best_result = result; |
659 | best_j = j; |
660 | } |
661 | |
662 | } |
663 | |
664 | factor = _sum2(cp1+best_j, cp2, len2) / sum_ri_2; |
665 | |
666 | return Py_BuildValue("(nf)" , best_j, factor); |
667 | } |
668 | |
669 | /* |
670 | ** findfactor finds a factor f so that the energy in A-fB is minimal. |
671 | ** See the comment for findfit for details. |
672 | */ |
673 | /*[clinic input] |
674 | audioop.findfactor |
675 | |
676 | fragment: Py_buffer |
677 | reference: Py_buffer |
678 | / |
679 | |
680 | Return a factor F such that rms(add(fragment, mul(reference, -F))) is minimal. |
681 | [clinic start generated code]*/ |
682 | |
683 | static PyObject * |
684 | audioop_findfactor_impl(PyObject *module, Py_buffer *fragment, |
685 | Py_buffer *reference) |
686 | /*[clinic end generated code: output=14ea95652c1afcf8 input=816680301d012b21]*/ |
687 | { |
688 | const int16_t *cp1, *cp2; |
689 | Py_ssize_t len; |
690 | double sum_ri_2, sum_aij_ri, result; |
691 | |
692 | if (fragment->len & 1 || reference->len & 1) { |
693 | PyErr_SetString(get_audioop_state(module)->AudioopError, |
694 | "Strings should be even-sized" ); |
695 | return NULL; |
696 | } |
697 | if (fragment->len != reference->len) { |
698 | PyErr_SetString(get_audioop_state(module)->AudioopError, |
699 | "Samples should be same size" ); |
700 | return NULL; |
701 | } |
702 | cp1 = (const int16_t *)fragment->buf; |
703 | cp2 = (const int16_t *)reference->buf; |
704 | len = fragment->len >> 1; |
705 | sum_ri_2 = _sum2(cp2, cp2, len); |
706 | sum_aij_ri = _sum2(cp1, cp2, len); |
707 | |
708 | result = sum_aij_ri / sum_ri_2; |
709 | |
710 | return PyFloat_FromDouble(result); |
711 | } |
712 | |
713 | /* |
714 | ** findmax returns the index of the n-sized segment of the input sample |
715 | ** that contains the most energy. |
716 | */ |
717 | /*[clinic input] |
718 | audioop.findmax |
719 | |
720 | fragment: Py_buffer |
721 | length: Py_ssize_t |
722 | / |
723 | |
724 | Search fragment for a slice of specified number of samples with maximum energy. |
725 | [clinic start generated code]*/ |
726 | |
727 | static PyObject * |
728 | audioop_findmax_impl(PyObject *module, Py_buffer *fragment, |
729 | Py_ssize_t length) |
730 | /*[clinic end generated code: output=f008128233523040 input=2f304801ed42383c]*/ |
731 | { |
732 | const int16_t *cp1; |
733 | Py_ssize_t len1; |
734 | Py_ssize_t j, best_j; |
735 | double aj_m1, aj_lm1; |
736 | double result, best_result; |
737 | |
738 | if (fragment->len & 1) { |
739 | PyErr_SetString(get_audioop_state(module)->AudioopError, |
740 | "Strings should be even-sized" ); |
741 | return NULL; |
742 | } |
743 | cp1 = (const int16_t *)fragment->buf; |
744 | len1 = fragment->len >> 1; |
745 | |
746 | if (length < 0 || len1 < length) { |
747 | PyErr_SetString(get_audioop_state(module)->AudioopError, |
748 | "Input sample should be longer" ); |
749 | return NULL; |
750 | } |
751 | |
752 | result = _sum2(cp1, cp1, length); |
753 | |
754 | best_result = result; |
755 | best_j = 0; |
756 | |
757 | for ( j=1; j<=len1-length; j++) { |
758 | aj_m1 = (double)cp1[j-1]; |
759 | aj_lm1 = (double)cp1[j+length-1]; |
760 | |
761 | result = result + aj_lm1*aj_lm1 - aj_m1*aj_m1; |
762 | |
763 | if ( result > best_result ) { |
764 | best_result = result; |
765 | best_j = j; |
766 | } |
767 | |
768 | } |
769 | |
770 | return PyLong_FromSsize_t(best_j); |
771 | } |
772 | |
773 | /*[clinic input] |
774 | audioop.avgpp |
775 | |
776 | fragment: Py_buffer |
777 | width: int |
778 | / |
779 | |
780 | Return the average peak-peak value over all samples in the fragment. |
781 | [clinic start generated code]*/ |
782 | |
783 | static PyObject * |
784 | audioop_avgpp_impl(PyObject *module, Py_buffer *fragment, int width) |
785 | /*[clinic end generated code: output=269596b0d5ae0b2b input=0b3cceeae420a7d9]*/ |
786 | { |
787 | Py_ssize_t i; |
788 | int prevval, prevextremevalid = 0, prevextreme = 0; |
789 | double sum = 0.0; |
790 | unsigned int avg; |
791 | int diff, prevdiff, nextreme = 0; |
792 | |
793 | if (!audioop_check_parameters(module, fragment->len, width)) |
794 | return NULL; |
795 | if (fragment->len <= width) |
796 | return PyLong_FromLong(0); |
797 | prevval = GETRAWSAMPLE(width, fragment->buf, 0); |
798 | prevdiff = 17; /* Anything != 0, 1 */ |
799 | for (i = width; i < fragment->len; i += width) { |
800 | int val = GETRAWSAMPLE(width, fragment->buf, i); |
801 | if (val != prevval) { |
802 | diff = val < prevval; |
803 | if (prevdiff == !diff) { |
804 | /* Derivative changed sign. Compute difference to last |
805 | ** extreme value and remember. |
806 | */ |
807 | if (prevextremevalid) { |
808 | if (prevval < prevextreme) |
809 | sum += (double)((unsigned int)prevextreme - |
810 | (unsigned int)prevval); |
811 | else |
812 | sum += (double)((unsigned int)prevval - |
813 | (unsigned int)prevextreme); |
814 | nextreme++; |
815 | } |
816 | prevextremevalid = 1; |
817 | prevextreme = prevval; |
818 | } |
819 | prevval = val; |
820 | prevdiff = diff; |
821 | } |
822 | } |
823 | if ( nextreme == 0 ) |
824 | avg = 0; |
825 | else |
826 | avg = (unsigned int)(sum / (double)nextreme); |
827 | return PyLong_FromUnsignedLong(avg); |
828 | } |
829 | |
830 | /*[clinic input] |
831 | audioop.maxpp |
832 | |
833 | fragment: Py_buffer |
834 | width: int |
835 | / |
836 | |
837 | Return the maximum peak-peak value in the sound fragment. |
838 | [clinic start generated code]*/ |
839 | |
840 | static PyObject * |
841 | audioop_maxpp_impl(PyObject *module, Py_buffer *fragment, int width) |
842 | /*[clinic end generated code: output=5b918ed5dbbdb978 input=671a13e1518f80a1]*/ |
843 | { |
844 | Py_ssize_t i; |
845 | int prevval, prevextremevalid = 0, prevextreme = 0; |
846 | unsigned int max = 0, extremediff; |
847 | int diff, prevdiff; |
848 | |
849 | if (!audioop_check_parameters(module, fragment->len, width)) |
850 | return NULL; |
851 | if (fragment->len <= width) |
852 | return PyLong_FromLong(0); |
853 | prevval = GETRAWSAMPLE(width, fragment->buf, 0); |
854 | prevdiff = 17; /* Anything != 0, 1 */ |
855 | for (i = width; i < fragment->len; i += width) { |
856 | int val = GETRAWSAMPLE(width, fragment->buf, i); |
857 | if (val != prevval) { |
858 | diff = val < prevval; |
859 | if (prevdiff == !diff) { |
860 | /* Derivative changed sign. Compute difference to |
861 | ** last extreme value and remember. |
862 | */ |
863 | if (prevextremevalid) { |
864 | if (prevval < prevextreme) |
865 | extremediff = (unsigned int)prevextreme - |
866 | (unsigned int)prevval; |
867 | else |
868 | extremediff = (unsigned int)prevval - |
869 | (unsigned int)prevextreme; |
870 | if ( extremediff > max ) |
871 | max = extremediff; |
872 | } |
873 | prevextremevalid = 1; |
874 | prevextreme = prevval; |
875 | } |
876 | prevval = val; |
877 | prevdiff = diff; |
878 | } |
879 | } |
880 | return PyLong_FromUnsignedLong(max); |
881 | } |
882 | |
883 | /*[clinic input] |
884 | audioop.cross |
885 | |
886 | fragment: Py_buffer |
887 | width: int |
888 | / |
889 | |
890 | Return the number of zero crossings in the fragment passed as an argument. |
891 | [clinic start generated code]*/ |
892 | |
893 | static PyObject * |
894 | audioop_cross_impl(PyObject *module, Py_buffer *fragment, int width) |
895 | /*[clinic end generated code: output=5938dcdd74a1f431 input=b1b3f15b83f6b41a]*/ |
896 | { |
897 | Py_ssize_t i; |
898 | int prevval; |
899 | Py_ssize_t ncross; |
900 | |
901 | if (!audioop_check_parameters(module, fragment->len, width)) |
902 | return NULL; |
903 | ncross = -1; |
904 | prevval = 17; /* Anything <> 0,1 */ |
905 | for (i = 0; i < fragment->len; i += width) { |
906 | int val = GETRAWSAMPLE(width, fragment->buf, i) < 0; |
907 | if (val != prevval) ncross++; |
908 | prevval = val; |
909 | } |
910 | return PyLong_FromSsize_t(ncross); |
911 | } |
912 | |
913 | /*[clinic input] |
914 | audioop.mul |
915 | |
916 | fragment: Py_buffer |
917 | width: int |
918 | factor: double |
919 | / |
920 | |
921 | Return a fragment that has all samples in the original fragment multiplied by the floating-point value factor. |
922 | [clinic start generated code]*/ |
923 | |
924 | static PyObject * |
925 | audioop_mul_impl(PyObject *module, Py_buffer *fragment, int width, |
926 | double factor) |
927 | /*[clinic end generated code: output=6cd48fe796da0ea4 input=c726667baa157d3c]*/ |
928 | { |
929 | signed char *ncp; |
930 | Py_ssize_t i; |
931 | double maxval, minval; |
932 | PyObject *rv; |
933 | |
934 | if (!audioop_check_parameters(module, fragment->len, width)) |
935 | return NULL; |
936 | |
937 | maxval = (double) maxvals[width]; |
938 | minval = (double) minvals[width]; |
939 | |
940 | rv = PyBytes_FromStringAndSize(NULL, fragment->len); |
941 | if (rv == NULL) |
942 | return NULL; |
943 | ncp = (signed char *)PyBytes_AsString(rv); |
944 | |
945 | for (i = 0; i < fragment->len; i += width) { |
946 | double val = GETRAWSAMPLE(width, fragment->buf, i); |
947 | int ival = fbound(val * factor, minval, maxval); |
948 | SETRAWSAMPLE(width, ncp, i, ival); |
949 | } |
950 | return rv; |
951 | } |
952 | |
953 | /*[clinic input] |
954 | audioop.tomono |
955 | |
956 | fragment: Py_buffer |
957 | width: int |
958 | lfactor: double |
959 | rfactor: double |
960 | / |
961 | |
962 | Convert a stereo fragment to a mono fragment. |
963 | [clinic start generated code]*/ |
964 | |
965 | static PyObject * |
966 | audioop_tomono_impl(PyObject *module, Py_buffer *fragment, int width, |
967 | double lfactor, double rfactor) |
968 | /*[clinic end generated code: output=235c8277216d4e4e input=c4ec949b3f4dddfa]*/ |
969 | { |
970 | signed char *cp, *ncp; |
971 | Py_ssize_t len, i; |
972 | double maxval, minval; |
973 | PyObject *rv; |
974 | |
975 | cp = fragment->buf; |
976 | len = fragment->len; |
977 | if (!audioop_check_parameters(module, len, width)) |
978 | return NULL; |
979 | if (((len / width) & 1) != 0) { |
980 | PyErr_SetString(get_audioop_state(module)->AudioopError, |
981 | "not a whole number of frames" ); |
982 | return NULL; |
983 | } |
984 | |
985 | maxval = (double) maxvals[width]; |
986 | minval = (double) minvals[width]; |
987 | |
988 | rv = PyBytes_FromStringAndSize(NULL, len/2); |
989 | if (rv == NULL) |
990 | return NULL; |
991 | ncp = (signed char *)PyBytes_AsString(rv); |
992 | |
993 | for (i = 0; i < len; i += width*2) { |
994 | double val1 = GETRAWSAMPLE(width, cp, i); |
995 | double val2 = GETRAWSAMPLE(width, cp, i + width); |
996 | double val = val1 * lfactor + val2 * rfactor; |
997 | int ival = fbound(val, minval, maxval); |
998 | SETRAWSAMPLE(width, ncp, i/2, ival); |
999 | } |
1000 | return rv; |
1001 | } |
1002 | |
1003 | /*[clinic input] |
1004 | audioop.tostereo |
1005 | |
1006 | fragment: Py_buffer |
1007 | width: int |
1008 | lfactor: double |
1009 | rfactor: double |
1010 | / |
1011 | |
1012 | Generate a stereo fragment from a mono fragment. |
1013 | [clinic start generated code]*/ |
1014 | |
1015 | static PyObject * |
1016 | audioop_tostereo_impl(PyObject *module, Py_buffer *fragment, int width, |
1017 | double lfactor, double rfactor) |
1018 | /*[clinic end generated code: output=046f13defa5f1595 input=27b6395ebfdff37a]*/ |
1019 | { |
1020 | signed char *ncp; |
1021 | Py_ssize_t i; |
1022 | double maxval, minval; |
1023 | PyObject *rv; |
1024 | |
1025 | if (!audioop_check_parameters(module, fragment->len, width)) |
1026 | return NULL; |
1027 | |
1028 | maxval = (double) maxvals[width]; |
1029 | minval = (double) minvals[width]; |
1030 | |
1031 | if (fragment->len > PY_SSIZE_T_MAX/2) { |
1032 | PyErr_SetString(PyExc_MemoryError, |
1033 | "not enough memory for output buffer" ); |
1034 | return NULL; |
1035 | } |
1036 | |
1037 | rv = PyBytes_FromStringAndSize(NULL, fragment->len*2); |
1038 | if (rv == NULL) |
1039 | return NULL; |
1040 | ncp = (signed char *)PyBytes_AsString(rv); |
1041 | |
1042 | for (i = 0; i < fragment->len; i += width) { |
1043 | double val = GETRAWSAMPLE(width, fragment->buf, i); |
1044 | int val1 = fbound(val * lfactor, minval, maxval); |
1045 | int val2 = fbound(val * rfactor, minval, maxval); |
1046 | SETRAWSAMPLE(width, ncp, i*2, val1); |
1047 | SETRAWSAMPLE(width, ncp, i*2 + width, val2); |
1048 | } |
1049 | return rv; |
1050 | } |
1051 | |
1052 | /*[clinic input] |
1053 | audioop.add |
1054 | |
1055 | fragment1: Py_buffer |
1056 | fragment2: Py_buffer |
1057 | width: int |
1058 | / |
1059 | |
1060 | Return a fragment which is the addition of the two samples passed as parameters. |
1061 | [clinic start generated code]*/ |
1062 | |
1063 | static PyObject * |
1064 | audioop_add_impl(PyObject *module, Py_buffer *fragment1, |
1065 | Py_buffer *fragment2, int width) |
1066 | /*[clinic end generated code: output=60140af4d1aab6f2 input=4a8d4bae4c1605c7]*/ |
1067 | { |
1068 | signed char *ncp; |
1069 | Py_ssize_t i; |
1070 | int minval, maxval, newval; |
1071 | PyObject *rv; |
1072 | |
1073 | if (!audioop_check_parameters(module, fragment1->len, width)) |
1074 | return NULL; |
1075 | if (fragment1->len != fragment2->len) { |
1076 | PyErr_SetString(get_audioop_state(module)->AudioopError, |
1077 | "Lengths should be the same" ); |
1078 | return NULL; |
1079 | } |
1080 | |
1081 | maxval = maxvals[width]; |
1082 | minval = minvals[width]; |
1083 | |
1084 | rv = PyBytes_FromStringAndSize(NULL, fragment1->len); |
1085 | if (rv == NULL) |
1086 | return NULL; |
1087 | ncp = (signed char *)PyBytes_AsString(rv); |
1088 | |
1089 | for (i = 0; i < fragment1->len; i += width) { |
1090 | int val1 = GETRAWSAMPLE(width, fragment1->buf, i); |
1091 | int val2 = GETRAWSAMPLE(width, fragment2->buf, i); |
1092 | |
1093 | if (width < 4) { |
1094 | newval = val1 + val2; |
1095 | /* truncate in case of overflow */ |
1096 | if (newval > maxval) |
1097 | newval = maxval; |
1098 | else if (newval < minval) |
1099 | newval = minval; |
1100 | } |
1101 | else { |
1102 | double fval = (double)val1 + (double)val2; |
1103 | /* truncate in case of overflow */ |
1104 | newval = fbound(fval, minval, maxval); |
1105 | } |
1106 | |
1107 | SETRAWSAMPLE(width, ncp, i, newval); |
1108 | } |
1109 | return rv; |
1110 | } |
1111 | |
1112 | /*[clinic input] |
1113 | audioop.bias |
1114 | |
1115 | fragment: Py_buffer |
1116 | width: int |
1117 | bias: int |
1118 | / |
1119 | |
1120 | Return a fragment that is the original fragment with a bias added to each sample. |
1121 | [clinic start generated code]*/ |
1122 | |
1123 | static PyObject * |
1124 | audioop_bias_impl(PyObject *module, Py_buffer *fragment, int width, int bias) |
1125 | /*[clinic end generated code: output=6e0aa8f68f045093 input=2b5cce5c3bb4838c]*/ |
1126 | { |
1127 | signed char *ncp; |
1128 | Py_ssize_t i; |
1129 | unsigned int val = 0, mask; |
1130 | PyObject *rv; |
1131 | |
1132 | if (!audioop_check_parameters(module, fragment->len, width)) |
1133 | return NULL; |
1134 | |
1135 | rv = PyBytes_FromStringAndSize(NULL, fragment->len); |
1136 | if (rv == NULL) |
1137 | return NULL; |
1138 | ncp = (signed char *)PyBytes_AsString(rv); |
1139 | |
1140 | mask = masks[width]; |
1141 | |
1142 | for (i = 0; i < fragment->len; i += width) { |
1143 | if (width == 1) |
1144 | val = GETINTX(unsigned char, fragment->buf, i); |
1145 | else if (width == 2) |
1146 | val = GETINTX(uint16_t, fragment->buf, i); |
1147 | else if (width == 3) |
1148 | val = ((unsigned int)GETINT24(fragment->buf, i)) & 0xffffffu; |
1149 | else { |
1150 | assert(width == 4); |
1151 | val = GETINTX(uint32_t, fragment->buf, i); |
1152 | } |
1153 | |
1154 | val += (unsigned int)bias; |
1155 | /* wrap around in case of overflow */ |
1156 | val &= mask; |
1157 | |
1158 | if (width == 1) |
1159 | SETINTX(unsigned char, ncp, i, val); |
1160 | else if (width == 2) |
1161 | SETINTX(uint16_t, ncp, i, val); |
1162 | else if (width == 3) |
1163 | SETINT24(ncp, i, (int)val); |
1164 | else { |
1165 | assert(width == 4); |
1166 | SETINTX(uint32_t, ncp, i, val); |
1167 | } |
1168 | } |
1169 | return rv; |
1170 | } |
1171 | |
1172 | /*[clinic input] |
1173 | audioop.reverse |
1174 | |
1175 | fragment: Py_buffer |
1176 | width: int |
1177 | / |
1178 | |
1179 | Reverse the samples in a fragment and returns the modified fragment. |
1180 | [clinic start generated code]*/ |
1181 | |
1182 | static PyObject * |
1183 | audioop_reverse_impl(PyObject *module, Py_buffer *fragment, int width) |
1184 | /*[clinic end generated code: output=b44135698418da14 input=668f890cf9f9d225]*/ |
1185 | { |
1186 | unsigned char *ncp; |
1187 | Py_ssize_t i; |
1188 | PyObject *rv; |
1189 | |
1190 | if (!audioop_check_parameters(module, fragment->len, width)) |
1191 | return NULL; |
1192 | |
1193 | rv = PyBytes_FromStringAndSize(NULL, fragment->len); |
1194 | if (rv == NULL) |
1195 | return NULL; |
1196 | ncp = (unsigned char *)PyBytes_AsString(rv); |
1197 | |
1198 | for (i = 0; i < fragment->len; i += width) { |
1199 | int val = GETRAWSAMPLE(width, fragment->buf, i); |
1200 | SETRAWSAMPLE(width, ncp, fragment->len - i - width, val); |
1201 | } |
1202 | return rv; |
1203 | } |
1204 | |
1205 | /*[clinic input] |
1206 | audioop.byteswap |
1207 | |
1208 | fragment: Py_buffer |
1209 | width: int |
1210 | / |
1211 | |
1212 | Convert big-endian samples to little-endian and vice versa. |
1213 | [clinic start generated code]*/ |
1214 | |
1215 | static PyObject * |
1216 | audioop_byteswap_impl(PyObject *module, Py_buffer *fragment, int width) |
1217 | /*[clinic end generated code: output=50838a9e4b87cd4d input=fae7611ceffa5c82]*/ |
1218 | { |
1219 | unsigned char *ncp; |
1220 | Py_ssize_t i; |
1221 | PyObject *rv; |
1222 | |
1223 | if (!audioop_check_parameters(module, fragment->len, width)) |
1224 | return NULL; |
1225 | |
1226 | rv = PyBytes_FromStringAndSize(NULL, fragment->len); |
1227 | if (rv == NULL) |
1228 | return NULL; |
1229 | ncp = (unsigned char *)PyBytes_AsString(rv); |
1230 | |
1231 | for (i = 0; i < fragment->len; i += width) { |
1232 | int j; |
1233 | for (j = 0; j < width; j++) |
1234 | ncp[i + width - 1 - j] = ((unsigned char *)fragment->buf)[i + j]; |
1235 | } |
1236 | return rv; |
1237 | } |
1238 | |
1239 | /*[clinic input] |
1240 | audioop.lin2lin |
1241 | |
1242 | fragment: Py_buffer |
1243 | width: int |
1244 | newwidth: int |
1245 | / |
1246 | |
1247 | Convert samples between 1-, 2-, 3- and 4-byte formats. |
1248 | [clinic start generated code]*/ |
1249 | |
1250 | static PyObject * |
1251 | audioop_lin2lin_impl(PyObject *module, Py_buffer *fragment, int width, |
1252 | int newwidth) |
1253 | /*[clinic end generated code: output=17b14109248f1d99 input=5ce08c8aa2f24d96]*/ |
1254 | { |
1255 | unsigned char *ncp; |
1256 | Py_ssize_t i, j; |
1257 | PyObject *rv; |
1258 | |
1259 | if (!audioop_check_parameters(module, fragment->len, width)) |
1260 | return NULL; |
1261 | if (!audioop_check_size(module, newwidth)) |
1262 | return NULL; |
1263 | |
1264 | if (fragment->len/width > PY_SSIZE_T_MAX/newwidth) { |
1265 | PyErr_SetString(PyExc_MemoryError, |
1266 | "not enough memory for output buffer" ); |
1267 | return NULL; |
1268 | } |
1269 | rv = PyBytes_FromStringAndSize(NULL, (fragment->len/width)*newwidth); |
1270 | if (rv == NULL) |
1271 | return NULL; |
1272 | ncp = (unsigned char *)PyBytes_AsString(rv); |
1273 | |
1274 | for (i = j = 0; i < fragment->len; i += width, j += newwidth) { |
1275 | int val = GETSAMPLE32(width, fragment->buf, i); |
1276 | SETSAMPLE32(newwidth, ncp, j, val); |
1277 | } |
1278 | return rv; |
1279 | } |
1280 | |
1281 | static int |
1282 | gcd(int a, int b) |
1283 | { |
1284 | while (b > 0) { |
1285 | int tmp = a % b; |
1286 | a = b; |
1287 | b = tmp; |
1288 | } |
1289 | return a; |
1290 | } |
1291 | |
1292 | /*[clinic input] |
1293 | audioop.ratecv |
1294 | |
1295 | fragment: Py_buffer |
1296 | width: int |
1297 | nchannels: int |
1298 | inrate: int |
1299 | outrate: int |
1300 | state: object |
1301 | weightA: int = 1 |
1302 | weightB: int = 0 |
1303 | / |
1304 | |
1305 | Convert the frame rate of the input fragment. |
1306 | [clinic start generated code]*/ |
1307 | |
1308 | static PyObject * |
1309 | audioop_ratecv_impl(PyObject *module, Py_buffer *fragment, int width, |
1310 | int nchannels, int inrate, int outrate, PyObject *state, |
1311 | int weightA, int weightB) |
1312 | /*[clinic end generated code: output=624038e843243139 input=aff3acdc94476191]*/ |
1313 | { |
1314 | char *cp, *ncp; |
1315 | Py_ssize_t len; |
1316 | int chan, d, *prev_i, *cur_i, cur_o; |
1317 | PyObject *samps, *str, *rv = NULL, *channel; |
1318 | int bytes_per_frame; |
1319 | |
1320 | if (!audioop_check_size(module, width)) |
1321 | return NULL; |
1322 | if (nchannels < 1) { |
1323 | PyErr_SetString(get_audioop_state(module)->AudioopError, |
1324 | "# of channels should be >= 1" ); |
1325 | return NULL; |
1326 | } |
1327 | if (width > INT_MAX / nchannels) { |
1328 | /* This overflow test is rigorously correct because |
1329 | both multiplicands are >= 1. Use the argument names |
1330 | from the docs for the error msg. */ |
1331 | PyErr_SetString(PyExc_OverflowError, |
1332 | "width * nchannels too big for a C int" ); |
1333 | return NULL; |
1334 | } |
1335 | bytes_per_frame = width * nchannels; |
1336 | if (weightA < 1 || weightB < 0) { |
1337 | PyErr_SetString(get_audioop_state(module)->AudioopError, |
1338 | "weightA should be >= 1, weightB should be >= 0" ); |
1339 | return NULL; |
1340 | } |
1341 | assert(fragment->len >= 0); |
1342 | if (fragment->len % bytes_per_frame != 0) { |
1343 | PyErr_SetString(get_audioop_state(module)->AudioopError, |
1344 | "not a whole number of frames" ); |
1345 | return NULL; |
1346 | } |
1347 | if (inrate <= 0 || outrate <= 0) { |
1348 | PyErr_SetString(get_audioop_state(module)->AudioopError, |
1349 | "sampling rate not > 0" ); |
1350 | return NULL; |
1351 | } |
1352 | /* divide inrate and outrate by their greatest common divisor */ |
1353 | d = gcd(inrate, outrate); |
1354 | inrate /= d; |
1355 | outrate /= d; |
1356 | /* divide weightA and weightB by their greatest common divisor */ |
1357 | d = gcd(weightA, weightB); |
1358 | weightA /= d; |
1359 | weightB /= d; |
1360 | |
1361 | if ((size_t)nchannels > SIZE_MAX/sizeof(int)) { |
1362 | PyErr_SetString(PyExc_MemoryError, |
1363 | "not enough memory for output buffer" ); |
1364 | return NULL; |
1365 | } |
1366 | prev_i = (int *) PyMem_Malloc(nchannels * sizeof(int)); |
1367 | cur_i = (int *) PyMem_Malloc(nchannels * sizeof(int)); |
1368 | if (prev_i == NULL || cur_i == NULL) { |
1369 | (void) PyErr_NoMemory(); |
1370 | goto exit; |
1371 | } |
1372 | |
1373 | len = fragment->len / bytes_per_frame; /* # of frames */ |
1374 | |
1375 | if (state == Py_None) { |
1376 | d = -outrate; |
1377 | for (chan = 0; chan < nchannels; chan++) |
1378 | prev_i[chan] = cur_i[chan] = 0; |
1379 | } |
1380 | else { |
1381 | if (!PyTuple_Check(state)) { |
1382 | PyErr_SetString(PyExc_TypeError, "state must be a tuple or None" ); |
1383 | goto exit; |
1384 | } |
1385 | if (!PyArg_ParseTuple(state, |
1386 | "iO!;ratecv(): illegal state argument" , |
1387 | &d, &PyTuple_Type, &samps)) |
1388 | goto exit; |
1389 | if (PyTuple_Size(samps) != nchannels) { |
1390 | PyErr_SetString(get_audioop_state(module)->AudioopError, |
1391 | "illegal state argument" ); |
1392 | goto exit; |
1393 | } |
1394 | for (chan = 0; chan < nchannels; chan++) { |
1395 | channel = PyTuple_GetItem(samps, chan); |
1396 | if (!PyTuple_Check(channel)) { |
1397 | PyErr_SetString(PyExc_TypeError, |
1398 | "ratecv(): illegal state argument" ); |
1399 | goto exit; |
1400 | } |
1401 | if (!PyArg_ParseTuple(channel, |
1402 | "ii;ratecv(): illegal state argument" , |
1403 | &prev_i[chan], &cur_i[chan])) |
1404 | { |
1405 | goto exit; |
1406 | } |
1407 | } |
1408 | } |
1409 | |
1410 | /* str <- Space for the output buffer. */ |
1411 | if (len == 0) |
1412 | str = PyBytes_FromStringAndSize(NULL, 0); |
1413 | else { |
1414 | /* There are len input frames, so we need (mathematically) |
1415 | ceiling(len*outrate/inrate) output frames, and each frame |
1416 | requires bytes_per_frame bytes. Computing this |
1417 | without spurious overflow is the challenge; we can |
1418 | settle for a reasonable upper bound, though, in this |
1419 | case ceiling(len/inrate) * outrate. */ |
1420 | |
1421 | /* compute ceiling(len/inrate) without overflow */ |
1422 | Py_ssize_t q = 1 + (len - 1) / inrate; |
1423 | if (outrate > PY_SSIZE_T_MAX / q / bytes_per_frame) |
1424 | str = NULL; |
1425 | else |
1426 | str = PyBytes_FromStringAndSize(NULL, |
1427 | q * outrate * bytes_per_frame); |
1428 | } |
1429 | if (str == NULL) { |
1430 | PyErr_SetString(PyExc_MemoryError, |
1431 | "not enough memory for output buffer" ); |
1432 | goto exit; |
1433 | } |
1434 | ncp = PyBytes_AsString(str); |
1435 | cp = fragment->buf; |
1436 | |
1437 | for (;;) { |
1438 | while (d < 0) { |
1439 | if (len == 0) { |
1440 | samps = PyTuple_New(nchannels); |
1441 | if (samps == NULL) |
1442 | goto exit; |
1443 | for (chan = 0; chan < nchannels; chan++) |
1444 | PyTuple_SetItem(samps, chan, |
1445 | Py_BuildValue("(ii)" , |
1446 | prev_i[chan], |
1447 | cur_i[chan])); |
1448 | if (PyErr_Occurred()) |
1449 | goto exit; |
1450 | /* We have checked before that the length |
1451 | * of the string fits into int. */ |
1452 | len = (Py_ssize_t)(ncp - PyBytes_AsString(str)); |
1453 | rv = PyBytes_FromStringAndSize |
1454 | (PyBytes_AsString(str), len); |
1455 | Py_DECREF(str); |
1456 | str = rv; |
1457 | if (str == NULL) |
1458 | goto exit; |
1459 | rv = Py_BuildValue("(O(iO))" , str, d, samps); |
1460 | Py_DECREF(samps); |
1461 | Py_DECREF(str); |
1462 | goto exit; /* return rv */ |
1463 | } |
1464 | for (chan = 0; chan < nchannels; chan++) { |
1465 | prev_i[chan] = cur_i[chan]; |
1466 | cur_i[chan] = GETSAMPLE32(width, cp, 0); |
1467 | cp += width; |
1468 | /* implements a simple digital filter */ |
1469 | cur_i[chan] = (int)( |
1470 | ((double)weightA * (double)cur_i[chan] + |
1471 | (double)weightB * (double)prev_i[chan]) / |
1472 | ((double)weightA + (double)weightB)); |
1473 | } |
1474 | len--; |
1475 | d += outrate; |
1476 | } |
1477 | while (d >= 0) { |
1478 | for (chan = 0; chan < nchannels; chan++) { |
1479 | cur_o = (int)(((double)prev_i[chan] * (double)d + |
1480 | (double)cur_i[chan] * (double)(outrate - d)) / |
1481 | (double)outrate); |
1482 | SETSAMPLE32(width, ncp, 0, cur_o); |
1483 | ncp += width; |
1484 | } |
1485 | d -= inrate; |
1486 | } |
1487 | } |
1488 | exit: |
1489 | PyMem_Free(prev_i); |
1490 | PyMem_Free(cur_i); |
1491 | return rv; |
1492 | } |
1493 | |
1494 | /*[clinic input] |
1495 | audioop.lin2ulaw |
1496 | |
1497 | fragment: Py_buffer |
1498 | width: int |
1499 | / |
1500 | |
1501 | Convert samples in the audio fragment to u-LAW encoding. |
1502 | [clinic start generated code]*/ |
1503 | |
1504 | static PyObject * |
1505 | audioop_lin2ulaw_impl(PyObject *module, Py_buffer *fragment, int width) |
1506 | /*[clinic end generated code: output=14fb62b16fe8ea8e input=2450d1b870b6bac2]*/ |
1507 | { |
1508 | unsigned char *ncp; |
1509 | Py_ssize_t i; |
1510 | PyObject *rv; |
1511 | |
1512 | if (!audioop_check_parameters(module, fragment->len, width)) |
1513 | return NULL; |
1514 | |
1515 | rv = PyBytes_FromStringAndSize(NULL, fragment->len/width); |
1516 | if (rv == NULL) |
1517 | return NULL; |
1518 | ncp = (unsigned char *)PyBytes_AsString(rv); |
1519 | |
1520 | for (i = 0; i < fragment->len; i += width) { |
1521 | int val = GETSAMPLE32(width, fragment->buf, i); |
1522 | *ncp++ = st_14linear2ulaw(val >> 18); |
1523 | } |
1524 | return rv; |
1525 | } |
1526 | |
1527 | /*[clinic input] |
1528 | audioop.ulaw2lin |
1529 | |
1530 | fragment: Py_buffer |
1531 | width: int |
1532 | / |
1533 | |
1534 | Convert sound fragments in u-LAW encoding to linearly encoded sound fragments. |
1535 | [clinic start generated code]*/ |
1536 | |
1537 | static PyObject * |
1538 | audioop_ulaw2lin_impl(PyObject *module, Py_buffer *fragment, int width) |
1539 | /*[clinic end generated code: output=378356b047521ba2 input=45d53ddce5be7d06]*/ |
1540 | { |
1541 | unsigned char *cp; |
1542 | signed char *ncp; |
1543 | Py_ssize_t i; |
1544 | PyObject *rv; |
1545 | |
1546 | if (!audioop_check_size(module, width)) |
1547 | return NULL; |
1548 | |
1549 | if (fragment->len > PY_SSIZE_T_MAX/width) { |
1550 | PyErr_SetString(PyExc_MemoryError, |
1551 | "not enough memory for output buffer" ); |
1552 | return NULL; |
1553 | } |
1554 | rv = PyBytes_FromStringAndSize(NULL, fragment->len*width); |
1555 | if (rv == NULL) |
1556 | return NULL; |
1557 | ncp = (signed char *)PyBytes_AsString(rv); |
1558 | |
1559 | cp = fragment->buf; |
1560 | for (i = 0; i < fragment->len*width; i += width) { |
1561 | int val = st_ulaw2linear16(*cp++) << 16; |
1562 | SETSAMPLE32(width, ncp, i, val); |
1563 | } |
1564 | return rv; |
1565 | } |
1566 | |
1567 | /*[clinic input] |
1568 | audioop.lin2alaw |
1569 | |
1570 | fragment: Py_buffer |
1571 | width: int |
1572 | / |
1573 | |
1574 | Convert samples in the audio fragment to a-LAW encoding. |
1575 | [clinic start generated code]*/ |
1576 | |
1577 | static PyObject * |
1578 | audioop_lin2alaw_impl(PyObject *module, Py_buffer *fragment, int width) |
1579 | /*[clinic end generated code: output=d076f130121a82f0 input=ffb1ef8bb39da945]*/ |
1580 | { |
1581 | unsigned char *ncp; |
1582 | Py_ssize_t i; |
1583 | PyObject *rv; |
1584 | |
1585 | if (!audioop_check_parameters(module, fragment->len, width)) |
1586 | return NULL; |
1587 | |
1588 | rv = PyBytes_FromStringAndSize(NULL, fragment->len/width); |
1589 | if (rv == NULL) |
1590 | return NULL; |
1591 | ncp = (unsigned char *)PyBytes_AsString(rv); |
1592 | |
1593 | for (i = 0; i < fragment->len; i += width) { |
1594 | int val = GETSAMPLE32(width, fragment->buf, i); |
1595 | *ncp++ = st_linear2alaw(val >> 19); |
1596 | } |
1597 | return rv; |
1598 | } |
1599 | |
1600 | /*[clinic input] |
1601 | audioop.alaw2lin |
1602 | |
1603 | fragment: Py_buffer |
1604 | width: int |
1605 | / |
1606 | |
1607 | Convert sound fragments in a-LAW encoding to linearly encoded sound fragments. |
1608 | [clinic start generated code]*/ |
1609 | |
1610 | static PyObject * |
1611 | audioop_alaw2lin_impl(PyObject *module, Py_buffer *fragment, int width) |
1612 | /*[clinic end generated code: output=85c365ec559df647 input=4140626046cd1772]*/ |
1613 | { |
1614 | unsigned char *cp; |
1615 | signed char *ncp; |
1616 | Py_ssize_t i; |
1617 | int val; |
1618 | PyObject *rv; |
1619 | |
1620 | if (!audioop_check_size(module, width)) |
1621 | return NULL; |
1622 | |
1623 | if (fragment->len > PY_SSIZE_T_MAX/width) { |
1624 | PyErr_SetString(PyExc_MemoryError, |
1625 | "not enough memory for output buffer" ); |
1626 | return NULL; |
1627 | } |
1628 | rv = PyBytes_FromStringAndSize(NULL, fragment->len*width); |
1629 | if (rv == NULL) |
1630 | return NULL; |
1631 | ncp = (signed char *)PyBytes_AsString(rv); |
1632 | cp = fragment->buf; |
1633 | |
1634 | for (i = 0; i < fragment->len*width; i += width) { |
1635 | val = st_alaw2linear16(*cp++) << 16; |
1636 | SETSAMPLE32(width, ncp, i, val); |
1637 | } |
1638 | return rv; |
1639 | } |
1640 | |
1641 | /*[clinic input] |
1642 | audioop.lin2adpcm |
1643 | |
1644 | fragment: Py_buffer |
1645 | width: int |
1646 | state: object |
1647 | / |
1648 | |
1649 | Convert samples to 4 bit Intel/DVI ADPCM encoding. |
1650 | [clinic start generated code]*/ |
1651 | |
1652 | static PyObject * |
1653 | audioop_lin2adpcm_impl(PyObject *module, Py_buffer *fragment, int width, |
1654 | PyObject *state) |
1655 | /*[clinic end generated code: output=cc19f159f16c6793 input=12919d549b90c90a]*/ |
1656 | { |
1657 | signed char *ncp; |
1658 | Py_ssize_t i; |
1659 | int step, valpred, delta, |
1660 | index, sign, vpdiff, diff; |
1661 | PyObject *rv = NULL, *str; |
1662 | int outputbuffer = 0, bufferstep; |
1663 | |
1664 | if (!audioop_check_parameters(module, fragment->len, width)) |
1665 | return NULL; |
1666 | |
1667 | /* Decode state, should have (value, step) */ |
1668 | if ( state == Py_None ) { |
1669 | /* First time, it seems. Set defaults */ |
1670 | valpred = 0; |
1671 | index = 0; |
1672 | } |
1673 | else if (!PyTuple_Check(state)) { |
1674 | PyErr_SetString(PyExc_TypeError, "state must be a tuple or None" ); |
1675 | return NULL; |
1676 | } |
1677 | else if (!PyArg_ParseTuple(state, "ii;lin2adpcm(): illegal state argument" , |
1678 | &valpred, &index)) |
1679 | { |
1680 | return NULL; |
1681 | } |
1682 | else if (valpred >= 0x8000 || valpred < -0x8000 || |
1683 | (size_t)index >= Py_ARRAY_LENGTH(stepsizeTable)) { |
1684 | PyErr_SetString(PyExc_ValueError, "bad state" ); |
1685 | return NULL; |
1686 | } |
1687 | |
1688 | str = PyBytes_FromStringAndSize(NULL, fragment->len/(width*2)); |
1689 | if (str == NULL) |
1690 | return NULL; |
1691 | ncp = (signed char *)PyBytes_AsString(str); |
1692 | |
1693 | step = stepsizeTable[index]; |
1694 | bufferstep = 1; |
1695 | |
1696 | for (i = 0; i < fragment->len; i += width) { |
1697 | int val = GETSAMPLE32(width, fragment->buf, i) >> 16; |
1698 | |
1699 | /* Step 1 - compute difference with previous value */ |
1700 | if (val < valpred) { |
1701 | diff = valpred - val; |
1702 | sign = 8; |
1703 | } |
1704 | else { |
1705 | diff = val - valpred; |
1706 | sign = 0; |
1707 | } |
1708 | |
1709 | /* Step 2 - Divide and clamp */ |
1710 | /* Note: |
1711 | ** This code *approximately* computes: |
1712 | ** delta = diff*4/step; |
1713 | ** vpdiff = (delta+0.5)*step/4; |
1714 | ** but in shift step bits are dropped. The net result of this |
1715 | ** is that even if you have fast mul/div hardware you cannot |
1716 | ** put it to good use since the fixup would be too expensive. |
1717 | */ |
1718 | delta = 0; |
1719 | vpdiff = (step >> 3); |
1720 | |
1721 | if ( diff >= step ) { |
1722 | delta = 4; |
1723 | diff -= step; |
1724 | vpdiff += step; |
1725 | } |
1726 | step >>= 1; |
1727 | if ( diff >= step ) { |
1728 | delta |= 2; |
1729 | diff -= step; |
1730 | vpdiff += step; |
1731 | } |
1732 | step >>= 1; |
1733 | if ( diff >= step ) { |
1734 | delta |= 1; |
1735 | vpdiff += step; |
1736 | } |
1737 | |
1738 | /* Step 3 - Update previous value */ |
1739 | if ( sign ) |
1740 | valpred -= vpdiff; |
1741 | else |
1742 | valpred += vpdiff; |
1743 | |
1744 | /* Step 4 - Clamp previous value to 16 bits */ |
1745 | if ( valpred > 32767 ) |
1746 | valpred = 32767; |
1747 | else if ( valpred < -32768 ) |
1748 | valpred = -32768; |
1749 | |
1750 | /* Step 5 - Assemble value, update index and step values */ |
1751 | delta |= sign; |
1752 | |
1753 | index += indexTable[delta]; |
1754 | if ( index < 0 ) index = 0; |
1755 | if ( index > 88 ) index = 88; |
1756 | step = stepsizeTable[index]; |
1757 | |
1758 | /* Step 6 - Output value */ |
1759 | if ( bufferstep ) { |
1760 | outputbuffer = (delta << 4) & 0xf0; |
1761 | } else { |
1762 | *ncp++ = (delta & 0x0f) | outputbuffer; |
1763 | } |
1764 | bufferstep = !bufferstep; |
1765 | } |
1766 | rv = Py_BuildValue("(O(ii))" , str, valpred, index); |
1767 | Py_DECREF(str); |
1768 | return rv; |
1769 | } |
1770 | |
1771 | /*[clinic input] |
1772 | audioop.adpcm2lin |
1773 | |
1774 | fragment: Py_buffer |
1775 | width: int |
1776 | state: object |
1777 | / |
1778 | |
1779 | Decode an Intel/DVI ADPCM coded fragment to a linear fragment. |
1780 | [clinic start generated code]*/ |
1781 | |
1782 | static PyObject * |
1783 | audioop_adpcm2lin_impl(PyObject *module, Py_buffer *fragment, int width, |
1784 | PyObject *state) |
1785 | /*[clinic end generated code: output=3440ea105acb3456 input=f5221144f5ca9ef0]*/ |
1786 | { |
1787 | signed char *cp; |
1788 | signed char *ncp; |
1789 | Py_ssize_t i, outlen; |
1790 | int valpred, step, delta, index, sign, vpdiff; |
1791 | PyObject *rv, *str; |
1792 | int inputbuffer = 0, bufferstep; |
1793 | |
1794 | if (!audioop_check_size(module, width)) |
1795 | return NULL; |
1796 | |
1797 | /* Decode state, should have (value, step) */ |
1798 | if ( state == Py_None ) { |
1799 | /* First time, it seems. Set defaults */ |
1800 | valpred = 0; |
1801 | index = 0; |
1802 | } |
1803 | else if (!PyTuple_Check(state)) { |
1804 | PyErr_SetString(PyExc_TypeError, "state must be a tuple or None" ); |
1805 | return NULL; |
1806 | } |
1807 | else if (!PyArg_ParseTuple(state, "ii;adpcm2lin(): illegal state argument" , |
1808 | &valpred, &index)) |
1809 | { |
1810 | return NULL; |
1811 | } |
1812 | else if (valpred >= 0x8000 || valpred < -0x8000 || |
1813 | (size_t)index >= Py_ARRAY_LENGTH(stepsizeTable)) { |
1814 | PyErr_SetString(PyExc_ValueError, "bad state" ); |
1815 | return NULL; |
1816 | } |
1817 | |
1818 | if (fragment->len > (PY_SSIZE_T_MAX/2)/width) { |
1819 | PyErr_SetString(PyExc_MemoryError, |
1820 | "not enough memory for output buffer" ); |
1821 | return NULL; |
1822 | } |
1823 | outlen = fragment->len*width*2; |
1824 | str = PyBytes_FromStringAndSize(NULL, outlen); |
1825 | if (str == NULL) |
1826 | return NULL; |
1827 | ncp = (signed char *)PyBytes_AsString(str); |
1828 | cp = fragment->buf; |
1829 | |
1830 | step = stepsizeTable[index]; |
1831 | bufferstep = 0; |
1832 | |
1833 | for (i = 0; i < outlen; i += width) { |
1834 | /* Step 1 - get the delta value and compute next index */ |
1835 | if ( bufferstep ) { |
1836 | delta = inputbuffer & 0xf; |
1837 | } else { |
1838 | inputbuffer = *cp++; |
1839 | delta = (inputbuffer >> 4) & 0xf; |
1840 | } |
1841 | |
1842 | bufferstep = !bufferstep; |
1843 | |
1844 | /* Step 2 - Find new index value (for later) */ |
1845 | index += indexTable[delta]; |
1846 | if ( index < 0 ) index = 0; |
1847 | if ( index > 88 ) index = 88; |
1848 | |
1849 | /* Step 3 - Separate sign and magnitude */ |
1850 | sign = delta & 8; |
1851 | delta = delta & 7; |
1852 | |
1853 | /* Step 4 - Compute difference and new predicted value */ |
1854 | /* |
1855 | ** Computes 'vpdiff = (delta+0.5)*step/4', but see comment |
1856 | ** in adpcm_coder. |
1857 | */ |
1858 | vpdiff = step >> 3; |
1859 | if ( delta & 4 ) vpdiff += step; |
1860 | if ( delta & 2 ) vpdiff += step>>1; |
1861 | if ( delta & 1 ) vpdiff += step>>2; |
1862 | |
1863 | if ( sign ) |
1864 | valpred -= vpdiff; |
1865 | else |
1866 | valpred += vpdiff; |
1867 | |
1868 | /* Step 5 - clamp output value */ |
1869 | if ( valpred > 32767 ) |
1870 | valpred = 32767; |
1871 | else if ( valpred < -32768 ) |
1872 | valpred = -32768; |
1873 | |
1874 | /* Step 6 - Update step value */ |
1875 | step = stepsizeTable[index]; |
1876 | |
1877 | /* Step 6 - Output value */ |
1878 | SETSAMPLE32(width, ncp, i, valpred << 16); |
1879 | } |
1880 | |
1881 | rv = Py_BuildValue("(O(ii))" , str, valpred, index); |
1882 | Py_DECREF(str); |
1883 | return rv; |
1884 | } |
1885 | |
1886 | #include "clinic/audioop.c.h" |
1887 | |
1888 | static PyMethodDef audioop_methods[] = { |
1889 | AUDIOOP_MAX_METHODDEF |
1890 | AUDIOOP_MINMAX_METHODDEF |
1891 | AUDIOOP_AVG_METHODDEF |
1892 | AUDIOOP_MAXPP_METHODDEF |
1893 | AUDIOOP_AVGPP_METHODDEF |
1894 | AUDIOOP_RMS_METHODDEF |
1895 | AUDIOOP_FINDFIT_METHODDEF |
1896 | AUDIOOP_FINDMAX_METHODDEF |
1897 | AUDIOOP_FINDFACTOR_METHODDEF |
1898 | AUDIOOP_CROSS_METHODDEF |
1899 | AUDIOOP_MUL_METHODDEF |
1900 | AUDIOOP_ADD_METHODDEF |
1901 | AUDIOOP_BIAS_METHODDEF |
1902 | AUDIOOP_ULAW2LIN_METHODDEF |
1903 | AUDIOOP_LIN2ULAW_METHODDEF |
1904 | AUDIOOP_ALAW2LIN_METHODDEF |
1905 | AUDIOOP_LIN2ALAW_METHODDEF |
1906 | AUDIOOP_LIN2LIN_METHODDEF |
1907 | AUDIOOP_ADPCM2LIN_METHODDEF |
1908 | AUDIOOP_LIN2ADPCM_METHODDEF |
1909 | AUDIOOP_TOMONO_METHODDEF |
1910 | AUDIOOP_TOSTEREO_METHODDEF |
1911 | AUDIOOP_GETSAMPLE_METHODDEF |
1912 | AUDIOOP_REVERSE_METHODDEF |
1913 | AUDIOOP_BYTESWAP_METHODDEF |
1914 | AUDIOOP_RATECV_METHODDEF |
1915 | { 0, 0 } |
1916 | }; |
1917 | |
1918 | static int |
1919 | audioop_traverse(PyObject *module, visitproc visit, void *arg) |
1920 | { |
1921 | audioop_state *state = get_audioop_state(module); |
1922 | Py_VISIT(state->AudioopError); |
1923 | return 0; |
1924 | } |
1925 | |
1926 | static int |
1927 | audioop_clear(PyObject *module) |
1928 | { |
1929 | audioop_state *state = get_audioop_state(module); |
1930 | Py_CLEAR(state->AudioopError); |
1931 | return 0; |
1932 | } |
1933 | |
1934 | static void |
1935 | audioop_free(void *module) { |
1936 | audioop_clear((PyObject *)module); |
1937 | } |
1938 | |
1939 | static int |
1940 | audioop_exec(PyObject* module) |
1941 | { |
1942 | audioop_state *state = get_audioop_state(module); |
1943 | |
1944 | state->AudioopError = PyErr_NewException("audioop.error" , NULL, NULL); |
1945 | if (state->AudioopError == NULL) { |
1946 | return -1; |
1947 | } |
1948 | |
1949 | Py_INCREF(state->AudioopError); |
1950 | if (PyModule_AddObject(module, "error" , state->AudioopError) < 0) { |
1951 | Py_DECREF(state->AudioopError); |
1952 | return -1; |
1953 | } |
1954 | |
1955 | return 0; |
1956 | } |
1957 | |
1958 | static PyModuleDef_Slot audioop_slots[] = { |
1959 | {Py_mod_exec, audioop_exec}, |
1960 | {0, NULL} |
1961 | }; |
1962 | |
1963 | static struct PyModuleDef audioopmodule = { |
1964 | PyModuleDef_HEAD_INIT, |
1965 | "audioop" , |
1966 | NULL, |
1967 | sizeof(audioop_state), |
1968 | audioop_methods, |
1969 | audioop_slots, |
1970 | audioop_traverse, |
1971 | audioop_clear, |
1972 | audioop_free |
1973 | }; |
1974 | |
1975 | PyMODINIT_FUNC |
1976 | PyInit_audioop(void) |
1977 | { |
1978 | return PyModuleDef_Init(&audioopmodule); |
1979 | } |
1980 | |