1 /*
2  *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 
12 /*
13  * This header file includes all of the fix point signal processing library (SPL) function
14  * descriptions and declarations.
15  * For specific function calls, see bottom of file.
16  */
17 
18 #ifndef WEBRTC_SPL_SIGNAL_PROCESSING_LIBRARY_H_
19 #define WEBRTC_SPL_SIGNAL_PROCESSING_LIBRARY_H_
20 
21 #include <string.h>
22 #include "typedefs.h"
23 
24 #ifdef ARM_WINM
25 #include <Armintr.h> // intrinsic file for windows mobile
26 #endif
27 
28 // Macros specific for the fixed point implementation
29 #define WEBRTC_SPL_WORD16_MAX       32767
30 #define WEBRTC_SPL_WORD16_MIN       -32768
31 #define WEBRTC_SPL_WORD32_MAX       (WebRtc_Word32)0x7fffffff
32 #define WEBRTC_SPL_WORD32_MIN       (WebRtc_Word32)0x80000000
33 #define WEBRTC_SPL_MAX_LPC_ORDER    14
34 #define WEBRTC_SPL_MAX_SEED_USED    0x80000000L
35 #define WEBRTC_SPL_MIN(A, B)        (A < B ? A : B) // Get min value
36 #define WEBRTC_SPL_MAX(A, B)        (A > B ? A : B) // Get max value
37 #define WEBRTC_SPL_ABS_W16(a) \
38     (((WebRtc_Word16)a >= 0) ? ((WebRtc_Word16)a) : -((WebRtc_Word16)a))
39 #define WEBRTC_SPL_ABS_W32(a) \
40     (((WebRtc_Word32)a >= 0) ? ((WebRtc_Word32)a) : -((WebRtc_Word32)a))
41 
42 #if (defined WEBRTC_TARGET_PC)||(defined __TARGET_XSCALE)
43 #define WEBRTC_SPL_GET_BYTE(a, nr)  (((WebRtc_Word8 *)a)[nr])
44 #define WEBRTC_SPL_SET_BYTE(d_ptr, val, index) \
45     (((WebRtc_Word8 *)d_ptr)[index] = (val))
46 #elif defined WEBRTC_BIG_ENDIAN
47 #define WEBRTC_SPL_GET_BYTE(a, nr) \
48     ((((WebRtc_Word16 *)a)[nr >> 1]) >> (((nr + 1) & 0x1) * 8) & 0x00ff)
49 #define WEBRTC_SPL_SET_BYTE(d_ptr, val, index) \
50     ((WebRtc_Word16 *)d_ptr)[index >> 1] = \
51     ((((WebRtc_Word16 *)d_ptr)[index >> 1]) \
52     & (0x00ff << (8 * ((index) & 0x1)))) | (val << (8 * ((index + 1) & 0x1)))
53 #else
54 #define WEBRTC_SPL_GET_BYTE(a,nr) \
55     ((((WebRtc_Word16 *)(a))[(nr) >> 1]) >> (((nr) & 0x1) * 8) & 0x00ff)
56 #define WEBRTC_SPL_SET_BYTE(d_ptr, val, index) \
57     ((WebRtc_Word16 *)(d_ptr))[(index) >> 1] = \
58     ((((WebRtc_Word16 *)(d_ptr))[(index) >> 1]) \
59     & (0x00ff << (8 * (((index) + 1) & 0x1)))) | \
60     ((val) << (8 * ((index) & 0x1)))
61 #endif
62 
63 #define WEBRTC_SPL_MUL(a, b) \
64     ((WebRtc_Word32) ((WebRtc_Word32)(a) * (WebRtc_Word32)(b)))
65 #define WEBRTC_SPL_UMUL(a, b) \
66     ((WebRtc_UWord32) ((WebRtc_UWord32)(a) * (WebRtc_UWord32)(b)))
67 #define WEBRTC_SPL_UMUL_RSFT16(a, b) \
68     ((WebRtc_UWord32) ((WebRtc_UWord32)(a) * (WebRtc_UWord32)(b)) >> 16)
69 #define WEBRTC_SPL_UMUL_16_16(a, b) \
70     ((WebRtc_UWord32) (WebRtc_UWord16)(a) * (WebRtc_UWord16)(b))
71 #define WEBRTC_SPL_UMUL_16_16_RSFT16(a, b) \
72     (((WebRtc_UWord32) (WebRtc_UWord16)(a) * (WebRtc_UWord16)(b)) >> 16)
73 #define WEBRTC_SPL_UMUL_32_16(a, b) \
74     ((WebRtc_UWord32) ((WebRtc_UWord32)(a) * (WebRtc_UWord16)(b)))
75 #define WEBRTC_SPL_UMUL_32_16_RSFT16(a, b) \
76     ((WebRtc_UWord32) ((WebRtc_UWord32)(a) * (WebRtc_UWord16)(b)) >> 16)
77 #define WEBRTC_SPL_MUL_16_U16(a, b) \
78     ((WebRtc_Word32)(WebRtc_Word16)(a) * (WebRtc_UWord16)(b))
79 #define WEBRTC_SPL_DIV(a, b) \
80     ((WebRtc_Word32) ((WebRtc_Word32)(a) / (WebRtc_Word32)(b)))
81 #define WEBRTC_SPL_UDIV(a, b) \
82     ((WebRtc_UWord32) ((WebRtc_UWord32)(a) / (WebRtc_UWord32)(b)))
83 
84 #ifndef WEBRTC_ARCH_ARM_V7A
85 // For ARMv7 platforms, these are inline functions in spl_inl_armv7.h
86 #define WEBRTC_SPL_MUL_16_16(a, b) \
87     ((WebRtc_Word32) (((WebRtc_Word16)(a)) * ((WebRtc_Word16)(b))))
88 #define WEBRTC_SPL_MUL_16_32_RSFT16(a, b) \
89     (WEBRTC_SPL_MUL_16_16(a, b >> 16) \
90      + ((WEBRTC_SPL_MUL_16_16(a, (b & 0xffff) >> 1) + 0x4000) >> 15))
91 #define WEBRTC_SPL_MUL_32_32_RSFT32(a32a, a32b, b32) \
92     ((WebRtc_Word32)(WEBRTC_SPL_MUL_16_32_RSFT16(a32a, b32) \
93     + (WEBRTC_SPL_MUL_16_32_RSFT16(a32b, b32) >> 16)))
94 #define WEBRTC_SPL_MUL_32_32_RSFT32BI(a32, b32) \
95     ((WebRtc_Word32)(WEBRTC_SPL_MUL_16_32_RSFT16(( \
96     (WebRtc_Word16)(a32 >> 16)), b32) + \
97     (WEBRTC_SPL_MUL_16_32_RSFT16(( \
98     (WebRtc_Word16)((a32 & 0x0000FFFF) >> 1)), b32) >> 15)))
99 #endif
100 
101 #define WEBRTC_SPL_MUL_16_32_RSFT11(a, b) \
102     ((WEBRTC_SPL_MUL_16_16(a, (b) >> 16) << 5) \
103     + (((WEBRTC_SPL_MUL_16_U16(a, (WebRtc_UWord16)(b)) >> 1) + 0x0200) >> 10))
104 #define WEBRTC_SPL_MUL_16_32_RSFT14(a, b) \
105     ((WEBRTC_SPL_MUL_16_16(a, (b) >> 16) << 2) \
106     + (((WEBRTC_SPL_MUL_16_U16(a, (WebRtc_UWord16)(b)) >> 1) + 0x1000) >> 13))
107 #define WEBRTC_SPL_MUL_16_32_RSFT15(a, b) \
108     ((WEBRTC_SPL_MUL_16_16(a, (b) >> 16) << 1) \
109     + (((WEBRTC_SPL_MUL_16_U16(a, (WebRtc_UWord16)(b)) >> 1) + 0x2000) >> 14))
110 
111 #ifdef ARM_WINM
112 #define WEBRTC_SPL_MUL_16_16(a, b) \
113     _SmulLo_SW_SL((WebRtc_Word16)(a), (WebRtc_Word16)(b))
114 #endif
115 
116 #define WEBRTC_SPL_MUL_16_16_RSFT(a, b, c) \
117     (WEBRTC_SPL_MUL_16_16(a, b) >> (c))
118 
119 #define WEBRTC_SPL_MUL_16_16_RSFT_WITH_ROUND(a, b, c) \
120     ((WEBRTC_SPL_MUL_16_16(a, b) + ((WebRtc_Word32) \
121                                   (((WebRtc_Word32)1) << ((c) - 1)))) >> (c))
122 #define WEBRTC_SPL_MUL_16_16_RSFT_WITH_FIXROUND(a, b) \
123     ((WEBRTC_SPL_MUL_16_16(a, b) + ((WebRtc_Word32) (1 << 14))) >> 15)
124 
125 // C + the 32 most significant bits of A * B
126 #define WEBRTC_SPL_SCALEDIFF32(A, B, C) \
127     (C + (B >> 16) * A + (((WebRtc_UWord32)(0x0000FFFF & B) * A) >> 16))
128 
129 #define WEBRTC_SPL_ADD_SAT_W32(a, b)    WebRtcSpl_AddSatW32(a, b)
130 #define WEBRTC_SPL_SAT(a, b, c)         (b > a ? a : b < c ? c : b)
131 #define WEBRTC_SPL_MUL_32_16(a, b)      ((a) * (b))
132 
133 #define WEBRTC_SPL_SUB_SAT_W32(a, b)    WebRtcSpl_SubSatW32(a, b)
134 #define WEBRTC_SPL_ADD_SAT_W16(a, b)    WebRtcSpl_AddSatW16(a, b)
135 #define WEBRTC_SPL_SUB_SAT_W16(a, b)    WebRtcSpl_SubSatW16(a, b)
136 
137 // We cannot do casting here due to signed/unsigned problem
138 #define WEBRTC_SPL_IS_NEG(a)            ((a) & 0x80000000)
139 // Shifting with negative numbers allowed
140 // Positive means left shift
141 #define WEBRTC_SPL_SHIFT_W16(x, c) \
142     (((c) >= 0) ? ((x) << (c)) : ((x) >> (-(c))))
143 #define WEBRTC_SPL_SHIFT_W32(x, c) \
144     (((c) >= 0) ? ((x) << (c)) : ((x) >> (-(c))))
145 
146 // Shifting with negative numbers not allowed
147 // We cannot do casting here due to signed/unsigned problem
148 #define WEBRTC_SPL_RSHIFT_W16(x, c)     ((x) >> (c))
149 #define WEBRTC_SPL_LSHIFT_W16(x, c)     ((x) << (c))
150 #define WEBRTC_SPL_RSHIFT_W32(x, c)     ((x) >> (c))
151 #define WEBRTC_SPL_LSHIFT_W32(x, c)     ((x) << (c))
152 
153 #define WEBRTC_SPL_RSHIFT_U16(x, c)     ((WebRtc_UWord16)(x) >> (c))
154 #define WEBRTC_SPL_LSHIFT_U16(x, c)     ((WebRtc_UWord16)(x) << (c))
155 #define WEBRTC_SPL_RSHIFT_U32(x, c)     ((WebRtc_UWord32)(x) >> (c))
156 #define WEBRTC_SPL_LSHIFT_U32(x, c)     ((WebRtc_UWord32)(x) << (c))
157 
158 #define WEBRTC_SPL_VNEW(t, n)           (t *) malloc (sizeof (t) * (n))
159 #define WEBRTC_SPL_FREE                 free
160 
161 #define WEBRTC_SPL_RAND(a) \
162     ((WebRtc_Word16)(WEBRTC_SPL_MUL_16_16_RSFT((a), 18816, 7) & 0x00007fff))
163 
164 #ifdef __cplusplus
165 extern "C"
166 {
167 #endif
168 
169 #define WEBRTC_SPL_MEMCPY_W8(v1, v2, length) \
170    memcpy(v1, v2, (length) * sizeof(char))
171 #define WEBRTC_SPL_MEMCPY_W16(v1, v2, length) \
172    memcpy(v1, v2, (length) * sizeof(WebRtc_Word16))
173 
174 #define WEBRTC_SPL_MEMMOVE_W16(v1, v2, length) \
175    memmove(v1, v2, (length) * sizeof(WebRtc_Word16))
176 
177 // inline functions:
178 #include "spl_inl.h"
179 
180 // Get SPL Version
181 WebRtc_Word16 WebRtcSpl_get_version(char* version,
182                                     WebRtc_Word16 length_in_bytes);
183 
184 int WebRtcSpl_GetScalingSquare(WebRtc_Word16* in_vector,
185                                int in_vector_length,
186                                int times);
187 
188 // Copy and set operations. Implementation in copy_set_operations.c.
189 // Descriptions at bottom of file.
190 void WebRtcSpl_MemSetW16(WebRtc_Word16* vector,
191                          WebRtc_Word16 set_value,
192                          int vector_length);
193 void WebRtcSpl_MemSetW32(WebRtc_Word32* vector,
194                          WebRtc_Word32 set_value,
195                          int vector_length);
196 void WebRtcSpl_MemCpyReversedOrder(WebRtc_Word16* out_vector,
197                                    WebRtc_Word16* in_vector,
198                                    int vector_length);
199 WebRtc_Word16 WebRtcSpl_CopyFromEndW16(G_CONST WebRtc_Word16* in_vector,
200                                        WebRtc_Word16 in_vector_length,
201                                        WebRtc_Word16 samples,
202                                        WebRtc_Word16* out_vector);
203 WebRtc_Word16 WebRtcSpl_ZerosArrayW16(WebRtc_Word16* vector,
204                                       WebRtc_Word16 vector_length);
205 WebRtc_Word16 WebRtcSpl_ZerosArrayW32(WebRtc_Word32* vector,
206                                       WebRtc_Word16 vector_length);
207 WebRtc_Word16 WebRtcSpl_OnesArrayW16(WebRtc_Word16* vector,
208                                      WebRtc_Word16 vector_length);
209 WebRtc_Word16 WebRtcSpl_OnesArrayW32(WebRtc_Word32* vector,
210                                      WebRtc_Word16 vector_length);
211 // End: Copy and set operations.
212 
213 // Minimum and maximum operations. Implementation in min_max_operations.c.
214 // Descriptions at bottom of file.
215 WebRtc_Word16 WebRtcSpl_MaxAbsValueW16(const WebRtc_Word16* vector,
216                                        WebRtc_Word16 length);
217 WebRtc_Word32 WebRtcSpl_MaxAbsValueW32(G_CONST WebRtc_Word32* vector,
218                                        WebRtc_Word16 length);
219 WebRtc_Word16 WebRtcSpl_MinValueW16(G_CONST WebRtc_Word16* vector,
220                                     WebRtc_Word16 length);
221 WebRtc_Word32 WebRtcSpl_MinValueW32(G_CONST WebRtc_Word32* vector,
222                                     WebRtc_Word16 length);
223 WebRtc_Word16 WebRtcSpl_MaxValueW16(G_CONST WebRtc_Word16* vector,
224                                     WebRtc_Word16 length);
225 
226 WebRtc_Word16 WebRtcSpl_MaxAbsIndexW16(G_CONST WebRtc_Word16* vector,
227                                        WebRtc_Word16 length);
228 WebRtc_Word32 WebRtcSpl_MaxValueW32(G_CONST WebRtc_Word32* vector,
229                                     WebRtc_Word16 length);
230 WebRtc_Word16 WebRtcSpl_MinIndexW16(G_CONST WebRtc_Word16* vector,
231                                     WebRtc_Word16 length);
232 WebRtc_Word16 WebRtcSpl_MinIndexW32(G_CONST WebRtc_Word32* vector,
233                                     WebRtc_Word16 length);
234 WebRtc_Word16 WebRtcSpl_MaxIndexW16(G_CONST WebRtc_Word16* vector,
235                                     WebRtc_Word16 length);
236 WebRtc_Word16 WebRtcSpl_MaxIndexW32(G_CONST WebRtc_Word32* vector,
237                                     WebRtc_Word16 length);
238 // End: Minimum and maximum operations.
239 
240 // Vector scaling operations. Implementation in vector_scaling_operations.c.
241 // Description at bottom of file.
242 void WebRtcSpl_VectorBitShiftW16(WebRtc_Word16* out_vector,
243                                  WebRtc_Word16 vector_length,
244                                  G_CONST WebRtc_Word16* in_vector,
245                                  WebRtc_Word16 right_shifts);
246 void WebRtcSpl_VectorBitShiftW32(WebRtc_Word32* out_vector,
247                                  WebRtc_Word16 vector_length,
248                                  G_CONST WebRtc_Word32* in_vector,
249                                  WebRtc_Word16 right_shifts);
250 void WebRtcSpl_VectorBitShiftW32ToW16(WebRtc_Word16* out_vector,
251                                       WebRtc_Word16 vector_length,
252                                       G_CONST WebRtc_Word32* in_vector,
253                                       WebRtc_Word16 right_shifts);
254 
255 void WebRtcSpl_ScaleVector(G_CONST WebRtc_Word16* in_vector,
256                            WebRtc_Word16* out_vector,
257                            WebRtc_Word16 gain,
258                            WebRtc_Word16 vector_length,
259                            WebRtc_Word16 right_shifts);
260 void WebRtcSpl_ScaleVectorWithSat(G_CONST WebRtc_Word16* in_vector,
261                                   WebRtc_Word16* out_vector,
262                                   WebRtc_Word16 gain,
263                                   WebRtc_Word16 vector_length,
264                                   WebRtc_Word16 right_shifts);
265 void WebRtcSpl_ScaleAndAddVectors(G_CONST WebRtc_Word16* in_vector1,
266                                   WebRtc_Word16 gain1, int right_shifts1,
267                                   G_CONST WebRtc_Word16* in_vector2,
268                                   WebRtc_Word16 gain2, int right_shifts2,
269                                   WebRtc_Word16* out_vector,
270                                   int vector_length);
271 // End: Vector scaling operations.
272 
273 // iLBC specific functions. Implementations in ilbc_specific_functions.c.
274 // Description at bottom of file.
275 void WebRtcSpl_ScaleAndAddVectorsWithRound(WebRtc_Word16* in_vector1,
276                                            WebRtc_Word16 scale1,
277                                            WebRtc_Word16* in_vector2,
278                                            WebRtc_Word16 scale2,
279                                            WebRtc_Word16 right_shifts,
280                                            WebRtc_Word16* out_vector,
281                                            WebRtc_Word16 vector_length);
282 void WebRtcSpl_ReverseOrderMultArrayElements(WebRtc_Word16* out_vector,
283                                              G_CONST WebRtc_Word16* in_vector,
284                                              G_CONST WebRtc_Word16* window,
285                                              WebRtc_Word16 vector_length,
286                                              WebRtc_Word16 right_shifts);
287 void WebRtcSpl_ElementwiseVectorMult(WebRtc_Word16* out_vector,
288                                      G_CONST WebRtc_Word16* in_vector,
289                                      G_CONST WebRtc_Word16* window,
290                                      WebRtc_Word16 vector_length,
291                                      WebRtc_Word16 right_shifts);
292 void WebRtcSpl_AddVectorsAndShift(WebRtc_Word16* out_vector,
293                                   G_CONST WebRtc_Word16* in_vector1,
294                                   G_CONST WebRtc_Word16* in_vector2,
295                                   WebRtc_Word16 vector_length,
296                                   WebRtc_Word16 right_shifts);
297 void WebRtcSpl_AddAffineVectorToVector(WebRtc_Word16* out_vector,
298                                        WebRtc_Word16* in_vector,
299                                        WebRtc_Word16 gain,
300                                        WebRtc_Word32 add_constant,
301                                        WebRtc_Word16 right_shifts,
302                                        int vector_length);
303 void WebRtcSpl_AffineTransformVector(WebRtc_Word16* out_vector,
304                                      WebRtc_Word16* in_vector,
305                                      WebRtc_Word16 gain,
306                                      WebRtc_Word32 add_constant,
307                                      WebRtc_Word16 right_shifts,
308                                      int vector_length);
309 // End: iLBC specific functions.
310 
311 // Signal processing operations. Descriptions at bottom of this file.
312 int WebRtcSpl_AutoCorrelation(G_CONST WebRtc_Word16* vector,
313                               int vector_length, int order,
314                               WebRtc_Word32* result_vector,
315                               int* scale);
316 WebRtc_Word16 WebRtcSpl_LevinsonDurbin(WebRtc_Word32* auto_corr,
317                                        WebRtc_Word16* lpc_coef,
318                                        WebRtc_Word16* refl_coef,
319                                        WebRtc_Word16 order);
320 void WebRtcSpl_ReflCoefToLpc(G_CONST WebRtc_Word16* refl_coef,
321                              int use_order,
322                              WebRtc_Word16* lpc_coef);
323 void WebRtcSpl_LpcToReflCoef(WebRtc_Word16* lpc_coef,
324                              int use_order,
325                              WebRtc_Word16* refl_coef);
326 void WebRtcSpl_AutoCorrToReflCoef(G_CONST WebRtc_Word32* auto_corr,
327                                   int use_order,
328                                   WebRtc_Word16* refl_coef);
329 void WebRtcSpl_CrossCorrelation(WebRtc_Word32* cross_corr,
330                                 WebRtc_Word16* vector1,
331                                 WebRtc_Word16* vector2,
332                                 WebRtc_Word16 dim_vector,
333                                 WebRtc_Word16 dim_cross_corr,
334                                 WebRtc_Word16 right_shifts,
335                                 WebRtc_Word16 step_vector2);
336 void WebRtcSpl_GetHanningWindow(WebRtc_Word16* window, WebRtc_Word16 size);
337 void WebRtcSpl_SqrtOfOneMinusXSquared(WebRtc_Word16* in_vector,
338                                       int vector_length,
339                                       WebRtc_Word16* out_vector);
340 // End: Signal processing operations.
341 
342 // Randomization functions. Implementations collected in randomization_functions.c and
343 // descriptions at bottom of this file.
344 WebRtc_UWord32 WebRtcSpl_IncreaseSeed(WebRtc_UWord32* seed);
345 WebRtc_Word16 WebRtcSpl_RandU(WebRtc_UWord32* seed);
346 WebRtc_Word16 WebRtcSpl_RandN(WebRtc_UWord32* seed);
347 WebRtc_Word16 WebRtcSpl_RandUArray(WebRtc_Word16* vector,
348                                    WebRtc_Word16 vector_length,
349                                    WebRtc_UWord32* seed);
350 // End: Randomization functions.
351 
352 // Math functions
353 WebRtc_Word32 WebRtcSpl_Sqrt(WebRtc_Word32 value);
354 WebRtc_Word32 WebRtcSpl_SqrtFloor(WebRtc_Word32 value);
355 
356 // Divisions. Implementations collected in division_operations.c and
357 // descriptions at bottom of this file.
358 WebRtc_UWord32 WebRtcSpl_DivU32U16(WebRtc_UWord32 num, WebRtc_UWord16 den);
359 WebRtc_Word32 WebRtcSpl_DivW32W16(WebRtc_Word32 num, WebRtc_Word16 den);
360 WebRtc_Word16 WebRtcSpl_DivW32W16ResW16(WebRtc_Word32 num, WebRtc_Word16 den);
361 WebRtc_Word32 WebRtcSpl_DivResultInQ31(WebRtc_Word32 num, WebRtc_Word32 den);
362 WebRtc_Word32 WebRtcSpl_DivW32HiLow(WebRtc_Word32 num, WebRtc_Word16 den_hi,
363                                     WebRtc_Word16 den_low);
364 // End: Divisions.
365 
366 WebRtc_Word32 WebRtcSpl_Energy(WebRtc_Word16* vector,
367                                int vector_length,
368                                int* scale_factor);
369 
370 WebRtc_Word32 WebRtcSpl_DotProductWithScale(WebRtc_Word16* vector1,
371                                             WebRtc_Word16* vector2,
372                                             int vector_length,
373                                             int scaling);
374 
375 // Filter operations.
376 int WebRtcSpl_FilterAR(G_CONST WebRtc_Word16* ar_coef, int ar_coef_length,
377                        G_CONST WebRtc_Word16* in_vector, int in_vector_length,
378                        WebRtc_Word16* filter_state, int filter_state_length,
379                        WebRtc_Word16* filter_state_low,
380                        int filter_state_low_length, WebRtc_Word16* out_vector,
381                        WebRtc_Word16* out_vector_low, int out_vector_low_length);
382 
383 void WebRtcSpl_FilterMAFastQ12(WebRtc_Word16* in_vector,
384                                WebRtc_Word16* out_vector,
385                                WebRtc_Word16* ma_coef,
386                                WebRtc_Word16 ma_coef_length,
387                                WebRtc_Word16 vector_length);
388 void WebRtcSpl_FilterARFastQ12(WebRtc_Word16* in_vector,
389                                WebRtc_Word16* out_vector,
390                                WebRtc_Word16* ar_coef,
391                                WebRtc_Word16 ar_coef_length,
392                                WebRtc_Word16 vector_length);
393 int WebRtcSpl_DownsampleFast(WebRtc_Word16* in_vector,
394                              WebRtc_Word16 in_vector_length,
395                              WebRtc_Word16* out_vector,
396                              WebRtc_Word16 out_vector_length,
397                              WebRtc_Word16* ma_coef,
398                              WebRtc_Word16 ma_coef_length,
399                              WebRtc_Word16 factor,
400                              WebRtc_Word16 delay);
401 // End: Filter operations.
402 
403 // FFT operations
404 int WebRtcSpl_ComplexFFT(WebRtc_Word16 vector[], int stages, int mode);
405 int WebRtcSpl_ComplexIFFT(WebRtc_Word16 vector[], int stages, int mode);
406 void WebRtcSpl_ComplexBitReverse(WebRtc_Word16 vector[], int stages);
407 // End: FFT operations
408 
409 /************************************************************
410  *
411  * RESAMPLING FUNCTIONS AND THEIR STRUCTS ARE DEFINED BELOW
412  *
413  ************************************************************/
414 
415 /*******************************************************************
416  * resample.c
417  *
418  * Includes the following resampling combinations
419  * 22 kHz -> 16 kHz
420  * 16 kHz -> 22 kHz
421  * 22 kHz ->  8 kHz
422  *  8 kHz -> 22 kHz
423  *
424  ******************************************************************/
425 
426 // state structure for 22 -> 16 resampler
427 typedef struct
428 {
429     WebRtc_Word32 S_22_44[8];
430     WebRtc_Word32 S_44_32[8];
431     WebRtc_Word32 S_32_16[8];
432 } WebRtcSpl_State22khzTo16khz;
433 
434 void WebRtcSpl_Resample22khzTo16khz(const WebRtc_Word16* in,
435                                     WebRtc_Word16* out,
436                                     WebRtcSpl_State22khzTo16khz* state,
437                                     WebRtc_Word32* tmpmem);
438 
439 void WebRtcSpl_ResetResample22khzTo16khz(WebRtcSpl_State22khzTo16khz* state);
440 
441 // state structure for 16 -> 22 resampler
442 typedef struct
443 {
444     WebRtc_Word32 S_16_32[8];
445     WebRtc_Word32 S_32_22[8];
446 } WebRtcSpl_State16khzTo22khz;
447 
448 void WebRtcSpl_Resample16khzTo22khz(const WebRtc_Word16* in,
449                                     WebRtc_Word16* out,
450                                     WebRtcSpl_State16khzTo22khz* state,
451                                     WebRtc_Word32* tmpmem);
452 
453 void WebRtcSpl_ResetResample16khzTo22khz(WebRtcSpl_State16khzTo22khz* state);
454 
455 // state structure for 22 -> 8 resampler
456 typedef struct
457 {
458     WebRtc_Word32 S_22_22[16];
459     WebRtc_Word32 S_22_16[8];
460     WebRtc_Word32 S_16_8[8];
461 } WebRtcSpl_State22khzTo8khz;
462 
463 void WebRtcSpl_Resample22khzTo8khz(const WebRtc_Word16* in, WebRtc_Word16* out,
464                                    WebRtcSpl_State22khzTo8khz* state,
465                                    WebRtc_Word32* tmpmem);
466 
467 void WebRtcSpl_ResetResample22khzTo8khz(WebRtcSpl_State22khzTo8khz* state);
468 
469 // state structure for 8 -> 22 resampler
470 typedef struct
471 {
472     WebRtc_Word32 S_8_16[8];
473     WebRtc_Word32 S_16_11[8];
474     WebRtc_Word32 S_11_22[8];
475 } WebRtcSpl_State8khzTo22khz;
476 
477 void WebRtcSpl_Resample8khzTo22khz(const WebRtc_Word16* in, WebRtc_Word16* out,
478                                    WebRtcSpl_State8khzTo22khz* state,
479                                    WebRtc_Word32* tmpmem);
480 
481 void WebRtcSpl_ResetResample8khzTo22khz(WebRtcSpl_State8khzTo22khz* state);
482 
483 /*******************************************************************
484  * resample_fractional.c
485  * Functions for internal use in the other resample functions
486  *
487  * Includes the following resampling combinations
488  * 48 kHz -> 32 kHz
489  * 32 kHz -> 24 kHz
490  * 44 kHz -> 32 kHz
491  *
492  ******************************************************************/
493 
494 void WebRtcSpl_Resample48khzTo32khz(const WebRtc_Word32* In, WebRtc_Word32* Out,
495                                     const WebRtc_Word32 K);
496 
497 void WebRtcSpl_Resample32khzTo24khz(const WebRtc_Word32* In, WebRtc_Word32* Out,
498                                     const WebRtc_Word32 K);
499 
500 void WebRtcSpl_Resample44khzTo32khz(const WebRtc_Word32* In, WebRtc_Word32* Out,
501                                     const WebRtc_Word32 K);
502 
503 /*******************************************************************
504  * resample_48khz.c
505  *
506  * Includes the following resampling combinations
507  * 48 kHz -> 16 kHz
508  * 16 kHz -> 48 kHz
509  * 48 kHz ->  8 kHz
510  *  8 kHz -> 48 kHz
511  *
512  ******************************************************************/
513 
514 typedef struct
515 {
516     WebRtc_Word32 S_48_48[16];
517     WebRtc_Word32 S_48_32[8];
518     WebRtc_Word32 S_32_16[8];
519 } WebRtcSpl_State48khzTo16khz;
520 
521 void WebRtcSpl_Resample48khzTo16khz(const WebRtc_Word16* in, WebRtc_Word16* out,
522                                     WebRtcSpl_State48khzTo16khz* state,
523                                     WebRtc_Word32* tmpmem);
524 
525 void WebRtcSpl_ResetResample48khzTo16khz(WebRtcSpl_State48khzTo16khz* state);
526 
527 typedef struct
528 {
529     WebRtc_Word32 S_16_32[8];
530     WebRtc_Word32 S_32_24[8];
531     WebRtc_Word32 S_24_48[8];
532 } WebRtcSpl_State16khzTo48khz;
533 
534 void WebRtcSpl_Resample16khzTo48khz(const WebRtc_Word16* in, WebRtc_Word16* out,
535                                     WebRtcSpl_State16khzTo48khz* state,
536                                     WebRtc_Word32* tmpmem);
537 
538 void WebRtcSpl_ResetResample16khzTo48khz(WebRtcSpl_State16khzTo48khz* state);
539 
540 typedef struct
541 {
542     WebRtc_Word32 S_48_24[8];
543     WebRtc_Word32 S_24_24[16];
544     WebRtc_Word32 S_24_16[8];
545     WebRtc_Word32 S_16_8[8];
546 } WebRtcSpl_State48khzTo8khz;
547 
548 void WebRtcSpl_Resample48khzTo8khz(const WebRtc_Word16* in, WebRtc_Word16* out,
549                                    WebRtcSpl_State48khzTo8khz* state,
550                                    WebRtc_Word32* tmpmem);
551 
552 void WebRtcSpl_ResetResample48khzTo8khz(WebRtcSpl_State48khzTo8khz* state);
553 
554 typedef struct
555 {
556     WebRtc_Word32 S_8_16[8];
557     WebRtc_Word32 S_16_12[8];
558     WebRtc_Word32 S_12_24[8];
559     WebRtc_Word32 S_24_48[8];
560 } WebRtcSpl_State8khzTo48khz;
561 
562 void WebRtcSpl_Resample8khzTo48khz(const WebRtc_Word16* in, WebRtc_Word16* out,
563                                    WebRtcSpl_State8khzTo48khz* state,
564                                    WebRtc_Word32* tmpmem);
565 
566 void WebRtcSpl_ResetResample8khzTo48khz(WebRtcSpl_State8khzTo48khz* state);
567 
568 /*******************************************************************
569  * resample_by_2.c
570  *
571  * Includes down and up sampling by a factor of two.
572  *
573  ******************************************************************/
574 
575 void WebRtcSpl_DownsampleBy2(const WebRtc_Word16* in, const WebRtc_Word16 len,
576                              WebRtc_Word16* out, WebRtc_Word32* filtState);
577 
578 void WebRtcSpl_UpsampleBy2(const WebRtc_Word16* in, WebRtc_Word16 len, WebRtc_Word16* out,
579                            WebRtc_Word32* filtState);
580 
581 /************************************************************
582  * END OF RESAMPLING FUNCTIONS
583  ************************************************************/
584 void WebRtcSpl_AnalysisQMF(const WebRtc_Word16* in_data,
585                            WebRtc_Word16* low_band,
586                            WebRtc_Word16* high_band,
587                            WebRtc_Word32* filter_state1,
588                            WebRtc_Word32* filter_state2);
589 void WebRtcSpl_SynthesisQMF(const WebRtc_Word16* low_band,
590                             const WebRtc_Word16* high_band,
591                             WebRtc_Word16* out_data,
592                             WebRtc_Word32* filter_state1,
593                             WebRtc_Word32* filter_state2);
594 
595 #ifdef __cplusplus
596 }
597 #endif // __cplusplus
598 #endif // WEBRTC_SPL_SIGNAL_PROCESSING_LIBRARY_H_
599 
600 //
601 // WebRtcSpl_AddSatW16(...)
602 // WebRtcSpl_AddSatW32(...)
603 //
604 // Returns the result of a saturated 16-bit, respectively 32-bit, addition of
605 // the numbers specified by the |var1| and |var2| parameters.
606 //
607 // Input:
608 //      - var1      : Input variable 1
609 //      - var2      : Input variable 2
610 //
611 // Return value     : Added and saturated value
612 //
613 
614 //
615 // WebRtcSpl_SubSatW16(...)
616 // WebRtcSpl_SubSatW32(...)
617 //
618 // Returns the result of a saturated 16-bit, respectively 32-bit, subtraction
619 // of the numbers specified by the |var1| and |var2| parameters.
620 //
621 // Input:
622 //      - var1      : Input variable 1
623 //      - var2      : Input variable 2
624 //
625 // Returned value   : Subtracted and saturated value
626 //
627 
628 //
629 // WebRtcSpl_GetSizeInBits(...)
630 //
631 // Returns the # of bits that are needed at the most to represent the number
632 // specified by the |value| parameter.
633 //
634 // Input:
635 //      - value     : Input value
636 //
637 // Return value     : Number of bits needed to represent |value|
638 //
639 
640 //
641 // WebRtcSpl_NormW32(...)
642 //
643 // Norm returns the # of left shifts required to 32-bit normalize the 32-bit
644 // signed number specified by the |value| parameter.
645 //
646 // Input:
647 //      - value     : Input value
648 //
649 // Return value     : Number of bit shifts needed to 32-bit normalize |value|
650 //
651 
652 //
653 // WebRtcSpl_NormW16(...)
654 //
655 // Norm returns the # of left shifts required to 16-bit normalize the 16-bit
656 // signed number specified by the |value| parameter.
657 //
658 // Input:
659 //      - value     : Input value
660 //
661 // Return value     : Number of bit shifts needed to 32-bit normalize |value|
662 //
663 
664 //
665 // WebRtcSpl_NormU32(...)
666 //
667 // Norm returns the # of left shifts required to 32-bit normalize the unsigned
668 // 32-bit number specified by the |value| parameter.
669 //
670 // Input:
671 //      - value     : Input value
672 //
673 // Return value     : Number of bit shifts needed to 32-bit normalize |value|
674 //
675 
676 //
677 // WebRtcSpl_GetScalingSquare(...)
678 //
679 // Returns the # of bits required to scale the samples specified in the
680 // |in_vector| parameter so that, if the squares of the samples are added the
681 // # of times specified by the |times| parameter, the 32-bit addition will not
682 // overflow (result in WebRtc_Word32).
683 //
684 // Input:
685 //      - in_vector         : Input vector to check scaling on
686 //      - in_vector_length  : Samples in |in_vector|
687 //      - times             : Number of additions to be performed
688 //
689 // Return value             : Number of right bit shifts needed to avoid
690 //                            overflow in the addition calculation
691 //
692 
693 //
694 // WebRtcSpl_MemSetW16(...)
695 //
696 // Sets all the values in the WebRtc_Word16 vector |vector| of length
697 // |vector_length| to the specified value |set_value|
698 //
699 // Input:
700 //      - vector        : Pointer to the WebRtc_Word16 vector
701 //      - set_value     : Value specified
702 //      - vector_length : Length of vector
703 //
704 
705 //
706 // WebRtcSpl_MemSetW32(...)
707 //
708 // Sets all the values in the WebRtc_Word32 vector |vector| of length
709 // |vector_length| to the specified value |set_value|
710 //
711 // Input:
712 //      - vector        : Pointer to the WebRtc_Word16 vector
713 //      - set_value     : Value specified
714 //      - vector_length : Length of vector
715 //
716 
717 //
718 // WebRtcSpl_MemCpyReversedOrder(...)
719 //
720 // Copies all the values from the source WebRtc_Word16 vector |in_vector| to a
721 // destination WebRtc_Word16 vector |out_vector|. It is done in reversed order,
722 // meaning that the first sample of |in_vector| is copied to the last sample of
723 // the |out_vector|. The procedure continues until the last sample of
724 // |in_vector| has been copied to the first sample of |out_vector|. This
725 // creates a reversed vector. Used in e.g. prediction in iLBC.
726 //
727 // Input:
728 //      - in_vector     : Pointer to the first sample in a WebRtc_Word16 vector
729 //                        of length |length|
730 //      - vector_length : Number of elements to copy
731 //
732 // Output:
733 //      - out_vector    : Pointer to the last sample in a WebRtc_Word16 vector
734 //                        of length |length|
735 //
736 
737 //
738 // WebRtcSpl_CopyFromEndW16(...)
739 //
740 // Copies the rightmost |samples| of |in_vector| (of length |in_vector_length|)
741 // to the vector |out_vector|.
742 //
743 // Input:
744 //      - in_vector         : Input vector
745 //      - in_vector_length  : Number of samples in |in_vector|
746 //      - samples           : Number of samples to extract (from right side)
747 //                            from |in_vector|
748 //
749 // Output:
750 //      - out_vector        : Vector with the requested samples
751 //
752 // Return value             : Number of copied samples in |out_vector|
753 //
754 
755 //
756 // WebRtcSpl_ZerosArrayW16(...)
757 // WebRtcSpl_ZerosArrayW32(...)
758 //
759 // Inserts the value "zero" in all positions of a w16 and a w32 vector
760 // respectively.
761 //
762 // Input:
763 //      - vector_length : Number of samples in vector
764 //
765 // Output:
766 //      - vector        : Vector containing all zeros
767 //
768 // Return value         : Number of samples in vector
769 //
770 
771 //
772 // WebRtcSpl_OnesArrayW16(...)
773 // WebRtcSpl_OnesArrayW32(...)
774 //
775 // Inserts the value "one" in all positions of a w16 and a w32 vector
776 // respectively.
777 //
778 // Input:
779 //      - vector_length : Number of samples in vector
780 //
781 // Output:
782 //      - vector        : Vector containing all ones
783 //
784 // Return value         : Number of samples in vector
785 //
786 
787 //
788 // WebRtcSpl_MinValueW16(...)
789 // WebRtcSpl_MinValueW32(...)
790 //
791 // Returns the minimum value of a vector
792 //
793 // Input:
794 //      - vector        : Input vector
795 //      - vector_length : Number of samples in vector
796 //
797 // Return value         : Minimum sample value in vector
798 //
799 
800 //
801 // WebRtcSpl_MaxValueW16(...)
802 // WebRtcSpl_MaxValueW32(...)
803 //
804 // Returns the maximum value of a vector
805 //
806 // Input:
807 //      - vector        : Input vector
808 //      - vector_length : Number of samples in vector
809 //
810 // Return value         : Maximum sample value in vector
811 //
812 
813 //
814 // WebRtcSpl_MaxAbsValueW16(...)
815 // WebRtcSpl_MaxAbsValueW32(...)
816 //
817 // Returns the largest absolute value of a vector
818 //
819 // Input:
820 //      - vector        : Input vector
821 //      - vector_length : Number of samples in vector
822 //
823 // Return value         : Maximum absolute value in vector
824 //
825 
826 //
827 // WebRtcSpl_MaxAbsIndexW16(...)
828 //
829 // Returns the vector index to the largest absolute value of a vector
830 //
831 // Input:
832 //      - vector        : Input vector
833 //      - vector_length : Number of samples in vector
834 //
835 // Return value         : Index to maximum absolute value in vector
836 //
837 
838 //
839 // WebRtcSpl_MinIndexW16(...)
840 // WebRtcSpl_MinIndexW32(...)
841 //
842 // Returns the vector index to the minimum sample value of a vector
843 //
844 // Input:
845 //      - vector        : Input vector
846 //      - vector_length : Number of samples in vector
847 //
848 // Return value         : Index to minimum sample value in vector
849 //
850 
851 //
852 // WebRtcSpl_MaxIndexW16(...)
853 // WebRtcSpl_MaxIndexW32(...)
854 //
855 // Returns the vector index to the maximum sample value of a vector
856 //
857 // Input:
858 //      - vector        : Input vector
859 //      - vector_length : Number of samples in vector
860 //
861 // Return value         : Index to maximum sample value in vector
862 //
863 
864 //
865 // WebRtcSpl_VectorBitShiftW16(...)
866 // WebRtcSpl_VectorBitShiftW32(...)
867 //
868 // Bit shifts all the values in a vector up or downwards. Different calls for
869 // WebRtc_Word16 and WebRtc_Word32 vectors respectively.
870 //
871 // Input:
872 //      - vector_length : Length of vector
873 //      - in_vector     : Pointer to the vector that should be bit shifted
874 //      - right_shifts  : Number of right bit shifts (negative value gives left
875 //                        shifts)
876 //
877 // Output:
878 //      - out_vector    : Pointer to the result vector (can be the same as
879 //                        |in_vector|)
880 //
881 
882 //
883 // WebRtcSpl_VectorBitShiftW32ToW16(...)
884 //
885 // Bit shifts all the values in a WebRtc_Word32 vector up or downwards and
886 // stores the result as a WebRtc_Word16 vector
887 //
888 // Input:
889 //      - vector_length : Length of vector
890 //      - in_vector     : Pointer to the vector that should be bit shifted
891 //      - right_shifts  : Number of right bit shifts (negative value gives left
892 //                        shifts)
893 //
894 // Output:
895 //      - out_vector    : Pointer to the result vector (can be the same as
896 //                        |in_vector|)
897 //
898 
899 //
900 // WebRtcSpl_ScaleVector(...)
901 //
902 // Performs the vector operation:
903 //  out_vector[k] = (gain*in_vector[k])>>right_shifts
904 //
905 // Input:
906 //      - in_vector     : Input vector
907 //      - gain          : Scaling gain
908 //      - vector_length : Elements in the |in_vector|
909 //      - right_shifts  : Number of right bit shifts applied
910 //
911 // Output:
912 //      - out_vector    : Output vector (can be the same as |in_vector|)
913 //
914 
915 //
916 // WebRtcSpl_ScaleVectorWithSat(...)
917 //
918 // Performs the vector operation:
919 //  out_vector[k] = SATURATE( (gain*in_vector[k])>>right_shifts )
920 //
921 // Input:
922 //      - in_vector     : Input vector
923 //      - gain          : Scaling gain
924 //      - vector_length : Elements in the |in_vector|
925 //      - right_shifts  : Number of right bit shifts applied
926 //
927 // Output:
928 //      - out_vector    : Output vector (can be the same as |in_vector|)
929 //
930 
931 //
932 // WebRtcSpl_ScaleAndAddVectors(...)
933 //
934 // Performs the vector operation:
935 //  out_vector[k] = (gain1*in_vector1[k])>>right_shifts1
936 //                  + (gain2*in_vector2[k])>>right_shifts2
937 //
938 // Input:
939 //      - in_vector1    : Input vector 1
940 //      - gain1         : Gain to be used for vector 1
941 //      - right_shifts1 : Right bit shift to be used for vector 1
942 //      - in_vector2    : Input vector 2
943 //      - gain2         : Gain to be used for vector 2
944 //      - right_shifts2 : Right bit shift to be used for vector 2
945 //      - vector_length : Elements in the input vectors
946 //
947 // Output:
948 //      - out_vector    : Output vector
949 //
950 
951 //
952 // WebRtcSpl_ScaleAndAddVectorsWithRound(...)
953 //
954 // Performs the vector operation:
955 //
956 //  out_vector[k] = ((scale1*in_vector1[k]) + (scale2*in_vector2[k])
957 //                      + round_value) >> right_shifts
958 //
959 //      where:
960 //
961 //  round_value = (1<<right_shifts)>>1
962 //
963 // Input:
964 //      - in_vector1    : Input vector 1
965 //      - scale1        : Gain to be used for vector 1
966 //      - in_vector2    : Input vector 2
967 //      - scale2        : Gain to be used for vector 2
968 //      - right_shifts  : Number of right bit shifts to be applied
969 //      - vector_length : Number of elements in the input vectors
970 //
971 // Output:
972 //      - out_vector    : Output vector
973 //
974 
975 //
976 // WebRtcSpl_ReverseOrderMultArrayElements(...)
977 //
978 // Performs the vector operation:
979 //  out_vector[n] = (in_vector[n]*window[-n])>>right_shifts
980 //
981 // Input:
982 //      - in_vector     : Input vector
983 //      - window        : Window vector (should be reversed). The pointer
984 //                        should be set to the last value in the vector
985 //      - right_shifts  : Number of right bit shift to be applied after the
986 //                        multiplication
987 //      - vector_length : Number of elements in |in_vector|
988 //
989 // Output:
990 //      - out_vector    : Output vector (can be same as |in_vector|)
991 //
992 
993 //
994 // WebRtcSpl_ElementwiseVectorMult(...)
995 //
996 // Performs the vector operation:
997 //  out_vector[n] = (in_vector[n]*window[n])>>right_shifts
998 //
999 // Input:
1000 //      - in_vector     : Input vector
1001 //      - window        : Window vector.
1002 //      - right_shifts  : Number of right bit shift to be applied after the
1003 //                        multiplication
1004 //      - vector_length : Number of elements in |in_vector|
1005 //
1006 // Output:
1007 //      - out_vector    : Output vector (can be same as |in_vector|)
1008 //
1009 
1010 //
1011 // WebRtcSpl_AddVectorsAndShift(...)
1012 //
1013 // Performs the vector operation:
1014 //  out_vector[k] = (in_vector1[k] + in_vector2[k])>>right_shifts
1015 //
1016 // Input:
1017 //      - in_vector1    : Input vector 1
1018 //      - in_vector2    : Input vector 2
1019 //      - right_shifts  : Number of right bit shift to be applied after the
1020 //                        multiplication
1021 //      - vector_length : Number of elements in |in_vector1| and |in_vector2|
1022 //
1023 // Output:
1024 //      - out_vector    : Output vector (can be same as |in_vector1|)
1025 //
1026 
1027 //
1028 // WebRtcSpl_AddAffineVectorToVector(...)
1029 //
1030 // Adds an affine transformed vector to another vector |out_vector|, i.e,
1031 // performs
1032 //  out_vector[k] += (in_vector[k]*gain+add_constant)>>right_shifts
1033 //
1034 // Input:
1035 //      - in_vector     : Input vector
1036 //      - gain          : Gain value, used to multiply the in vector with
1037 //      - add_constant  : Constant value to add (usually 1<<(right_shifts-1),
1038 //                        but others can be used as well
1039 //      - right_shifts  : Number of right bit shifts (0-16)
1040 //      - vector_length : Number of samples in |in_vector| and |out_vector|
1041 //
1042 // Output:
1043 //      - out_vector    : Vector with the output
1044 //
1045 
1046 //
1047 // WebRtcSpl_AffineTransformVector(...)
1048 //
1049 // Affine transforms a vector, i.e, performs
1050 //  out_vector[k] = (in_vector[k]*gain+add_constant)>>right_shifts
1051 //
1052 // Input:
1053 //      - in_vector     : Input vector
1054 //      - gain          : Gain value, used to multiply the in vector with
1055 //      - add_constant  : Constant value to add (usually 1<<(right_shifts-1),
1056 //                        but others can be used as well
1057 //      - right_shifts  : Number of right bit shifts (0-16)
1058 //      - vector_length : Number of samples in |in_vector| and |out_vector|
1059 //
1060 // Output:
1061 //      - out_vector    : Vector with the output
1062 //
1063 
1064 //
1065 // WebRtcSpl_AutoCorrelation(...)
1066 //
1067 // A 32-bit fix-point implementation of auto-correlation computation
1068 //
1069 // Input:
1070 //      - vector        : Vector to calculate autocorrelation upon
1071 //      - vector_length : Length (in samples) of |vector|
1072 //      - order         : The order up to which the autocorrelation should be
1073 //                        calculated
1074 //
1075 // Output:
1076 //      - result_vector : auto-correlation values (values should be seen
1077 //                        relative to each other since the absolute values
1078 //                        might have been down shifted to avoid overflow)
1079 //
1080 //      - scale         : The number of left shifts required to obtain the
1081 //                        auto-correlation in Q0
1082 //
1083 // Return value         : Number of samples in |result_vector|, i.e., (order+1)
1084 //
1085 
1086 //
1087 // WebRtcSpl_LevinsonDurbin(...)
1088 //
1089 // A 32-bit fix-point implementation of the Levinson-Durbin algorithm that
1090 // does NOT use the 64 bit class
1091 //
1092 // Input:
1093 //      - auto_corr : Vector with autocorrelation values of length >=
1094 //                    |use_order|+1
1095 //      - use_order : The LPC filter order (support up to order 20)
1096 //
1097 // Output:
1098 //      - lpc_coef  : lpc_coef[0..use_order] LPC coefficients in Q12
1099 //      - refl_coef : refl_coef[0...use_order-1]| Reflection coefficients in
1100 //                    Q15
1101 //
1102 // Return value     : 1 for stable 0 for unstable
1103 //
1104 
1105 //
1106 // WebRtcSpl_ReflCoefToLpc(...)
1107 //
1108 // Converts reflection coefficients |refl_coef| to LPC coefficients |lpc_coef|.
1109 // This version is a 16 bit operation.
1110 //
1111 // NOTE: The 16 bit refl_coef -> lpc_coef conversion might result in a
1112 // "slightly unstable" filter (i.e., a pole just outside the unit circle) in
1113 // "rare" cases even if the reflection coefficients are stable.
1114 //
1115 // Input:
1116 //      - refl_coef : Reflection coefficients in Q15 that should be converted
1117 //                    to LPC coefficients
1118 //      - use_order : Number of coefficients in |refl_coef|
1119 //
1120 // Output:
1121 //      - lpc_coef  : LPC coefficients in Q12
1122 //
1123 
1124 //
1125 // WebRtcSpl_LpcToReflCoef(...)
1126 //
1127 // Converts LPC coefficients |lpc_coef| to reflection coefficients |refl_coef|.
1128 // This version is a 16 bit operation.
1129 // The conversion is implemented by the step-down algorithm.
1130 //
1131 // Input:
1132 //      - lpc_coef  : LPC coefficients in Q12, that should be converted to
1133 //                    reflection coefficients
1134 //      - use_order : Number of coefficients in |lpc_coef|
1135 //
1136 // Output:
1137 //      - refl_coef : Reflection coefficients in Q15.
1138 //
1139 
1140 //
1141 // WebRtcSpl_AutoCorrToReflCoef(...)
1142 //
1143 // Calculates reflection coefficients (16 bit) from auto-correlation values
1144 //
1145 // Input:
1146 //      - auto_corr : Auto-correlation values
1147 //      - use_order : Number of coefficients wanted be calculated
1148 //
1149 // Output:
1150 //      - refl_coef : Reflection coefficients in Q15.
1151 //
1152 
1153 //
1154 // WebRtcSpl_CrossCorrelation(...)
1155 //
1156 // Calculates the cross-correlation between two sequences |vector1| and
1157 // |vector2|. |vector1| is fixed and |vector2| slides as the pointer is
1158 // increased with the amount |step_vector2|
1159 //
1160 // Input:
1161 //      - vector1           : First sequence (fixed throughout the correlation)
1162 //      - vector2           : Second sequence (slides |step_vector2| for each
1163 //                            new correlation)
1164 //      - dim_vector        : Number of samples to use in the cross-correlation
1165 //      - dim_cross_corr    : Number of cross-correlations to calculate (the
1166 //                            start position for |vector2| is updated for each
1167 //                            new one)
1168 //      - right_shifts      : Number of right bit shifts to use. This will
1169 //                            become the output Q-domain.
1170 //      - step_vector2      : How many (positive or negative) steps the
1171 //                            |vector2| pointer should be updated for each new
1172 //                            cross-correlation value.
1173 //
1174 // Output:
1175 //      - cross_corr        : The cross-correlation in Q(-right_shifts)
1176 //
1177 
1178 //
1179 // WebRtcSpl_GetHanningWindow(...)
1180 //
1181 // Creates (the first half of) a Hanning window. Size must be at least 1 and
1182 // at most 512.
1183 //
1184 // Input:
1185 //      - size      : Length of the requested Hanning window (1 to 512)
1186 //
1187 // Output:
1188 //      - window    : Hanning vector in Q14.
1189 //
1190 
1191 //
1192 // WebRtcSpl_SqrtOfOneMinusXSquared(...)
1193 //
1194 // Calculates y[k] = sqrt(1 - x[k]^2) for each element of the input vector
1195 // |in_vector|. Input and output values are in Q15.
1196 //
1197 // Inputs:
1198 //      - in_vector     : Values to calculate sqrt(1 - x^2) of
1199 //      - vector_length : Length of vector |in_vector|
1200 //
1201 // Output:
1202 //      - out_vector    : Output values in Q15
1203 //
1204 
1205 //
1206 // WebRtcSpl_IncreaseSeed(...)
1207 //
1208 // Increases the seed (and returns the new value)
1209 //
1210 // Input:
1211 //      - seed      : Seed for random calculation
1212 //
1213 // Output:
1214 //      - seed      : Updated seed value
1215 //
1216 // Return value     : The new seed value
1217 //
1218 
1219 //
1220 // WebRtcSpl_RandU(...)
1221 //
1222 // Produces a uniformly distributed value in the WebRtc_Word16 range
1223 //
1224 // Input:
1225 //      - seed      : Seed for random calculation
1226 //
1227 // Output:
1228 //      - seed      : Updated seed value
1229 //
1230 // Return value     : Uniformly distributed value in the range
1231 //                    [Word16_MIN...Word16_MAX]
1232 //
1233 
1234 //
1235 // WebRtcSpl_RandN(...)
1236 //
1237 // Produces a normal distributed value in the WebRtc_Word16 range
1238 //
1239 // Input:
1240 //      - seed      : Seed for random calculation
1241 //
1242 // Output:
1243 //      - seed      : Updated seed value
1244 //
1245 // Return value     : N(0,1) value in the Q13 domain
1246 //
1247 
1248 //
1249 // WebRtcSpl_RandUArray(...)
1250 //
1251 // Produces a uniformly distributed vector with elements in the WebRtc_Word16
1252 // range
1253 //
1254 // Input:
1255 //      - vector_length : Samples wanted in the vector
1256 //      - seed          : Seed for random calculation
1257 //
1258 // Output:
1259 //      - vector        : Vector with the uniform values
1260 //      - seed          : Updated seed value
1261 //
1262 // Return value         : Number of samples in vector, i.e., |vector_length|
1263 //
1264 
1265 //
1266 // WebRtcSpl_Sqrt(...)
1267 //
1268 // Returns the square root of the input value |value|. The precision of this
1269 // function is integer precision, i.e., sqrt(8) gives 2 as answer.
1270 // If |value| is a negative number then 0 is returned.
1271 //
1272 // Algorithm:
1273 //
1274 // A sixth order Taylor Series expansion is used here to compute the square
1275 // root of a number y^0.5 = (1+x)^0.5
1276 // where
1277 // x = y-1
1278 //   = 1+(x/2)-0.5*((x/2)^2+0.5*((x/2)^3-0.625*((x/2)^4+0.875*((x/2)^5)
1279 // 0.5 <= x < 1
1280 //
1281 // Input:
1282 //      - value     : Value to calculate sqrt of
1283 //
1284 // Return value     : Result of the sqrt calculation
1285 //
1286 
1287 //
1288 // WebRtcSpl_SqrtFloor(...)
1289 //
1290 // Returns the square root of the input value |value|. The precision of this
1291 // function is rounding down integer precision, i.e., sqrt(8) gives 2 as answer.
1292 // If |value| is a negative number then 0 is returned.
1293 //
1294 // Algorithm:
1295 //
1296 // An iterative 4 cylce/bit routine
1297 //
1298 // Input:
1299 //      - value     : Value to calculate sqrt of
1300 //
1301 // Return value     : Result of the sqrt calculation
1302 //
1303 
1304 //
1305 // WebRtcSpl_DivU32U16(...)
1306 //
1307 // Divides a WebRtc_UWord32 |num| by a WebRtc_UWord16 |den|.
1308 //
1309 // If |den|==0, (WebRtc_UWord32)0xFFFFFFFF is returned.
1310 //
1311 // Input:
1312 //      - num       : Numerator
1313 //      - den       : Denominator
1314 //
1315 // Return value     : Result of the division (as a WebRtc_UWord32), i.e., the
1316 //                    integer part of num/den.
1317 //
1318 
1319 //
1320 // WebRtcSpl_DivW32W16(...)
1321 //
1322 // Divides a WebRtc_Word32 |num| by a WebRtc_Word16 |den|.
1323 //
1324 // If |den|==0, (WebRtc_Word32)0x7FFFFFFF is returned.
1325 //
1326 // Input:
1327 //      - num       : Numerator
1328 //      - den       : Denominator
1329 //
1330 // Return value     : Result of the division (as a WebRtc_Word32), i.e., the
1331 //                    integer part of num/den.
1332 //
1333 
1334 //
1335 // WebRtcSpl_DivW32W16ResW16(...)
1336 //
1337 // Divides a WebRtc_Word32 |num| by a WebRtc_Word16 |den|, assuming that the
1338 // result is less than 32768, otherwise an unpredictable result will occur.
1339 //
1340 // If |den|==0, (WebRtc_Word16)0x7FFF is returned.
1341 //
1342 // Input:
1343 //      - num       : Numerator
1344 //      - den       : Denominator
1345 //
1346 // Return value     : Result of the division (as a WebRtc_Word16), i.e., the
1347 //                    integer part of num/den.
1348 //
1349 
1350 //
1351 // WebRtcSpl_DivResultInQ31(...)
1352 //
1353 // Divides a WebRtc_Word32 |num| by a WebRtc_Word16 |den|, assuming that the
1354 // absolute value of the denominator is larger than the numerator, otherwise
1355 // an unpredictable result will occur.
1356 //
1357 // Input:
1358 //      - num       : Numerator
1359 //      - den       : Denominator
1360 //
1361 // Return value     : Result of the division in Q31.
1362 //
1363 
1364 //
1365 // WebRtcSpl_DivW32HiLow(...)
1366 //
1367 // Divides a WebRtc_Word32 |num| by a denominator in hi, low format. The
1368 // absolute value of the denominator has to be larger (or equal to) the
1369 // numerator.
1370 //
1371 // Input:
1372 //      - num       : Numerator
1373 //      - den_hi    : High part of denominator
1374 //      - den_low   : Low part of denominator
1375 //
1376 // Return value     : Divided value in Q31
1377 //
1378 
1379 //
1380 // WebRtcSpl_Energy(...)
1381 //
1382 // Calculates the energy of a vector
1383 //
1384 // Input:
1385 //      - vector        : Vector which the energy should be calculated on
1386 //      - vector_length : Number of samples in vector
1387 //
1388 // Output:
1389 //      - scale_factor  : Number of left bit shifts needed to get the physical
1390 //                        energy value, i.e, to get the Q0 value
1391 //
1392 // Return value         : Energy value in Q(-|scale_factor|)
1393 //
1394 
1395 //
1396 // WebRtcSpl_FilterAR(...)
1397 //
1398 // Performs a 32-bit AR filtering on a vector in Q12
1399 //
1400 // Input:
1401 //  - ar_coef                   : AR-coefficient vector (values in Q12),
1402 //                                ar_coef[0] must be 4096.
1403 //  - ar_coef_length            : Number of coefficients in |ar_coef|.
1404 //  - in_vector                 : Vector to be filtered.
1405 //  - in_vector_length          : Number of samples in |in_vector|.
1406 //  - filter_state              : Current state (higher part) of the filter.
1407 //  - filter_state_length       : Length (in samples) of |filter_state|.
1408 //  - filter_state_low          : Current state (lower part) of the filter.
1409 //  - filter_state_low_length   : Length (in samples) of |filter_state_low|.
1410 //  - out_vector_low_length     : Maximum length (in samples) of
1411 //                                |out_vector_low|.
1412 //
1413 // Output:
1414 //  - filter_state              : Updated state (upper part) vector.
1415 //  - filter_state_low          : Updated state (lower part) vector.
1416 //  - out_vector                : Vector containing the upper part of the
1417 //                                filtered values.
1418 //  - out_vector_low            : Vector containing the lower part of the
1419 //                                filtered values.
1420 //
1421 // Return value                 : Number of samples in the |out_vector|.
1422 //
1423 
1424 //
1425 // WebRtcSpl_FilterMAFastQ12(...)
1426 //
1427 // Performs a MA filtering on a vector in Q12
1428 //
1429 // Input:
1430 //      - in_vector         : Input samples (state in positions
1431 //                            in_vector[-order] .. in_vector[-1])
1432 //      - ma_coef           : Filter coefficients (in Q12)
1433 //      - ma_coef_length    : Number of B coefficients (order+1)
1434 //      - vector_length     : Number of samples to be filtered
1435 //
1436 // Output:
1437 //      - out_vector        : Filtered samples
1438 //
1439 
1440 //
1441 // WebRtcSpl_FilterARFastQ12(...)
1442 //
1443 // Performs a AR filtering on a vector in Q12
1444 //
1445 // Input:
1446 //      - in_vector         : Input samples
1447 //      - out_vector        : State information in positions
1448 //                            out_vector[-order] .. out_vector[-1]
1449 //      - ar_coef           : Filter coefficients (in Q12)
1450 //      - ar_coef_length    : Number of B coefficients (order+1)
1451 //      - vector_length     : Number of samples to be filtered
1452 //
1453 // Output:
1454 //      - out_vector        : Filtered samples
1455 //
1456 
1457 //
1458 // WebRtcSpl_DownsampleFast(...)
1459 //
1460 // Performs a MA down sampling filter on a vector
1461 //
1462 // Input:
1463 //      - in_vector         : Input samples (state in positions
1464 //                            in_vector[-order] .. in_vector[-1])
1465 //      - in_vector_length  : Number of samples in |in_vector| to be filtered.
1466 //                            This must be at least
1467 //                            |delay| + |factor|*(|out_vector_length|-1) + 1)
1468 //      - out_vector_length : Number of down sampled samples desired
1469 //      - ma_coef           : Filter coefficients (in Q12)
1470 //      - ma_coef_length    : Number of B coefficients (order+1)
1471 //      - factor            : Decimation factor
1472 //      - delay             : Delay of filter (compensated for in out_vector)
1473 //
1474 // Output:
1475 //      - out_vector        : Filtered samples
1476 //
1477 // Return value             : 0 if OK, -1 if |in_vector| is too short
1478 //
1479 
1480 //
1481 // WebRtcSpl_DotProductWithScale(...)
1482 //
1483 // Calculates the dot product between two (WebRtc_Word16) vectors
1484 //
1485 // Input:
1486 //      - vector1       : Vector 1
1487 //      - vector2       : Vector 2
1488 //      - vector_length : Number of samples used in the dot product
1489 //      - scaling       : The number of right bit shifts to apply on each term
1490 //                        during calculation to avoid overflow, i.e., the
1491 //                        output will be in Q(-|scaling|)
1492 //
1493 // Return value         : The dot product in Q(-scaling)
1494 //
1495 
1496 //
1497 // WebRtcSpl_ComplexIFFT(...)
1498 //
1499 // Complex Inverse FFT
1500 //
1501 // Computes an inverse complex 2^|stages|-point FFT on the input vector, which
1502 // is in bit-reversed order. The original content of the vector is destroyed in
1503 // the process, since the input is overwritten by the output, normal-ordered,
1504 // FFT vector. With X as the input complex vector, y as the output complex
1505 // vector and with M = 2^|stages|, the following is computed:
1506 //
1507 //        M-1
1508 // y(k) = sum[X(i)*[cos(2*pi*i*k/M) + j*sin(2*pi*i*k/M)]]
1509 //        i=0
1510 //
1511 // The implementations are optimized for speed, not for code size. It uses the
1512 // decimation-in-time algorithm with radix-2 butterfly technique.
1513 //
1514 // Input:
1515 //      - vector    : In pointer to complex vector containing 2^|stages|
1516 //                    real elements interleaved with 2^|stages| imaginary
1517 //                    elements.
1518 //                    [ReImReImReIm....]
1519 //                    The elements are in Q(-scale) domain, see more on Return
1520 //                    Value below.
1521 //
1522 //      - stages    : Number of FFT stages. Must be at least 3 and at most 10,
1523 //                    since the table WebRtcSpl_kSinTable1024[] is 1024
1524 //                    elements long.
1525 //
1526 //      - mode      : This parameter gives the user to choose how the FFT
1527 //                    should work.
1528 //                    mode==0: Low-complexity and Low-accuracy mode
1529 //                    mode==1: High-complexity and High-accuracy mode
1530 //
1531 // Output:
1532 //      - vector    : Out pointer to the FFT vector (the same as input).
1533 //
1534 // Return Value     : The scale value that tells the number of left bit shifts
1535 //                    that the elements in the |vector| should be shifted with
1536 //                    in order to get Q0 values, i.e. the physically correct
1537 //                    values. The scale parameter is always 0 or positive,
1538 //                    except if N>1024 (|stages|>10), which returns a scale
1539 //                    value of -1, indicating error.
1540 //
1541 
1542 //
1543 // WebRtcSpl_ComplexFFT(...)
1544 //
1545 // Complex FFT
1546 //
1547 // Computes a complex 2^|stages|-point FFT on the input vector, which is in
1548 // bit-reversed order. The original content of the vector is destroyed in
1549 // the process, since the input is overwritten by the output, normal-ordered,
1550 // FFT vector. With x as the input complex vector, Y as the output complex
1551 // vector and with M = 2^|stages|, the following is computed:
1552 //
1553 //              M-1
1554 // Y(k) = 1/M * sum[x(i)*[cos(2*pi*i*k/M) + j*sin(2*pi*i*k/M)]]
1555 //              i=0
1556 //
1557 // The implementations are optimized for speed, not for code size. It uses the
1558 // decimation-in-time algorithm with radix-2 butterfly technique.
1559 //
1560 // This routine prevents overflow by scaling by 2 before each FFT stage. This is
1561 // a fixed scaling, for proper normalization - there will be log2(n) passes, so
1562 // this results in an overall factor of 1/n, distributed to maximize arithmetic
1563 // accuracy.
1564 //
1565 // Input:
1566 //      - vector    : In pointer to complex vector containing 2^|stages| real
1567 //                    elements interleaved with 2^|stages| imaginary elements.
1568 //                    [ReImReImReIm....]
1569 //                    The output is in the Q0 domain.
1570 //
1571 //      - stages    : Number of FFT stages. Must be at least 3 and at most 10,
1572 //                    since the table WebRtcSpl_kSinTable1024[] is 1024
1573 //                    elements long.
1574 //
1575 //      - mode      : This parameter gives the user to choose how the FFT
1576 //                    should work.
1577 //                    mode==0: Low-complexity and Low-accuracy mode
1578 //                    mode==1: High-complexity and High-accuracy mode
1579 //
1580 // Output:
1581 //      - vector    : The output FFT vector is in the Q0 domain.
1582 //
1583 // Return value     : The scale parameter is always 0, except if N>1024,
1584 //                    which returns a scale value of -1, indicating error.
1585 //
1586 
1587 //
1588 // WebRtcSpl_ComplexBitReverse(...)
1589 //
1590 // Complex Bit Reverse
1591 //
1592 // This function bit-reverses the position of elements in the complex input
1593 // vector into the output vector.
1594 //
1595 // If you bit-reverse a linear-order array, you obtain a bit-reversed order
1596 // array. If you bit-reverse a bit-reversed order array, you obtain a
1597 // linear-order array.
1598 //
1599 // Input:
1600 //      - vector    : In pointer to complex vector containing 2^|stages| real
1601 //                    elements interleaved with 2^|stages| imaginary elements.
1602 //                    [ReImReImReIm....]
1603 //      - stages    : Number of FFT stages. Must be at least 3 and at most 10,
1604 //                    since the table WebRtcSpl_kSinTable1024[] is 1024
1605 //                    elements long.
1606 //
1607 // Output:
1608 //      - vector    : Out pointer to complex vector in bit-reversed order.
1609 //                    The input vector is over written.
1610 //
1611 
1612 //
1613 // WebRtcSpl_AnalysisQMF(...)
1614 //
1615 // Splits a 0-2*F Hz signal into two sub bands: 0-F Hz and F-2*F Hz. The
1616 // current version has F = 8000, therefore, a super-wideband audio signal is
1617 // split to lower-band 0-8 kHz and upper-band 8-16 kHz.
1618 //
1619 // Input:
1620 //      - in_data       : Wide band speech signal, 320 samples (10 ms)
1621 //
1622 // Input & Output:
1623 //      - filter_state1 : Filter state for first All-pass filter
1624 //      - filter_state2 : Filter state for second All-pass filter
1625 //
1626 // Output:
1627 //      - low_band      : Lower-band signal 0-8 kHz band, 160 samples (10 ms)
1628 //      - high_band     : Upper-band signal 8-16 kHz band (flipped in frequency
1629 //                        domain), 160 samples (10 ms)
1630 //
1631 
1632 //
1633 // WebRtcSpl_SynthesisQMF(...)
1634 //
1635 // Combines the two sub bands (0-F and F-2*F Hz) into a signal of 0-2*F
1636 // Hz, (current version has F = 8000 Hz). So the filter combines lower-band
1637 // (0-8 kHz) and upper-band (8-16 kHz) channels to obtain super-wideband 0-16
1638 // kHz audio.
1639 //
1640 // Input:
1641 //      - low_band      : The signal with the 0-8 kHz band, 160 samples (10 ms)
1642 //      - high_band     : The signal with the 8-16 kHz band, 160 samples (10 ms)
1643 //
1644 // Input & Output:
1645 //      - filter_state1 : Filter state for first All-pass filter
1646 //      - filter_state2 : Filter state for second All-pass filter
1647 //
1648 // Output:
1649 //      - out_data      : Super-wideband speech signal, 0-16 kHz
1650 //
1651 
1652 // WebRtc_Word16 WebRtcSpl_SatW32ToW16(...)
1653 //
1654 // This function saturates a 32-bit word into a 16-bit word.
1655 //
1656 // Input:
1657 //      - value32   : The value of a 32-bit word.
1658 //
1659 // Output:
1660 //      - out16     : the saturated 16-bit word.
1661 //
1662 
1663 // int32_t WebRtc_MulAccumW16(...)
1664 //
1665 // This function multiply a 16-bit word by a 16-bit word, and accumulate this
1666 // value to a 32-bit integer.
1667 //
1668 // Input:
1669 //      - a    : The value of the first 16-bit word.
1670 //      - b    : The value of the second 16-bit word.
1671 //      - c    : The value of an 32-bit integer.
1672 //
1673 // Return Value: The value of a * b + c.
1674 //
1675 
1676 // WebRtc_Word16 WebRtcSpl_get_version(...)
1677 //
1678 // This function gives the version string of the Signal Processing Library.
1679 //
1680 // Input:
1681 //      - length_in_bytes   : The size of Allocated space (in Bytes) where
1682 //                            the version number is written to (in string format).
1683 //
1684 // Output:
1685 //      - version           : Pointer to a buffer where the version number is written to.
1686 //
1687