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      1 /*
      2  *  Copyright (c) 2012 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 "webrtc/typedefs.h"
     23 
     24 // Macros specific for the fixed point implementation
     25 #define WEBRTC_SPL_WORD16_MAX       32767
     26 #define WEBRTC_SPL_WORD16_MIN       -32768
     27 #define WEBRTC_SPL_WORD32_MAX       (int32_t)0x7fffffff
     28 #define WEBRTC_SPL_WORD32_MIN       (int32_t)0x80000000
     29 #define WEBRTC_SPL_MAX_LPC_ORDER    14
     30 #define WEBRTC_SPL_MIN(A, B)        (A < B ? A : B)  // Get min value
     31 #define WEBRTC_SPL_MAX(A, B)        (A > B ? A : B)  // Get max value
     32 // TODO(kma/bjorn): For the next two macros, investigate how to correct the code
     33 // for inputs of a = WEBRTC_SPL_WORD16_MIN or WEBRTC_SPL_WORD32_MIN.
     34 #define WEBRTC_SPL_ABS_W16(a) \
     35     (((int16_t)a >= 0) ? ((int16_t)a) : -((int16_t)a))
     36 #define WEBRTC_SPL_ABS_W32(a) \
     37     (((int32_t)a >= 0) ? ((int32_t)a) : -((int32_t)a))
     38 
     39 #define WEBRTC_SPL_MUL(a, b) \
     40     ((int32_t) ((int32_t)(a) * (int32_t)(b)))
     41 #define WEBRTC_SPL_UMUL(a, b) \
     42     ((uint32_t) ((uint32_t)(a) * (uint32_t)(b)))
     43 #define WEBRTC_SPL_UMUL_32_16(a, b) \
     44     ((uint32_t) ((uint32_t)(a) * (uint16_t)(b)))
     45 #define WEBRTC_SPL_MUL_16_U16(a, b) \
     46     ((int32_t)(int16_t)(a) * (uint16_t)(b))
     47 
     48 #ifndef WEBRTC_ARCH_ARM_V7
     49 // For ARMv7 platforms, these are inline functions in spl_inl_armv7.h
     50 #ifndef MIPS32_LE
     51 // For MIPS platforms, these are inline functions in spl_inl_mips.h
     52 #define WEBRTC_SPL_MUL_16_16(a, b) \
     53     ((int32_t) (((int16_t)(a)) * ((int16_t)(b))))
     54 #define WEBRTC_SPL_MUL_16_32_RSFT16(a, b) \
     55     (WEBRTC_SPL_MUL_16_16(a, b >> 16) \
     56      + ((WEBRTC_SPL_MUL_16_16(a, (b & 0xffff) >> 1) + 0x4000) >> 15))
     57 #endif
     58 #endif
     59 
     60 #define WEBRTC_SPL_MUL_16_32_RSFT11(a, b) \
     61     ((WEBRTC_SPL_MUL_16_16(a, (b) >> 16) << 5) \
     62     + (((WEBRTC_SPL_MUL_16_U16(a, (uint16_t)(b)) >> 1) + 0x0200) >> 10))
     63 #define WEBRTC_SPL_MUL_16_32_RSFT14(a, b) \
     64     ((WEBRTC_SPL_MUL_16_16(a, (b) >> 16) << 2) \
     65     + (((WEBRTC_SPL_MUL_16_U16(a, (uint16_t)(b)) >> 1) + 0x1000) >> 13))
     66 #define WEBRTC_SPL_MUL_16_32_RSFT15(a, b) \
     67     ((WEBRTC_SPL_MUL_16_16(a, (b) >> 16) << 1) \
     68     + (((WEBRTC_SPL_MUL_16_U16(a, (uint16_t)(b)) >> 1) + 0x2000) >> 14))
     69 
     70 #define WEBRTC_SPL_MUL_16_16_RSFT(a, b, c) \
     71     (WEBRTC_SPL_MUL_16_16(a, b) >> (c))
     72 
     73 #define WEBRTC_SPL_MUL_16_16_RSFT_WITH_ROUND(a, b, c) \
     74     ((WEBRTC_SPL_MUL_16_16(a, b) + ((int32_t) \
     75                                   (((int32_t)1) << ((c) - 1)))) >> (c))
     76 
     77 // C + the 32 most significant bits of A * B
     78 #define WEBRTC_SPL_SCALEDIFF32(A, B, C) \
     79     (C + (B >> 16) * A + (((uint32_t)(0x0000FFFF & B) * A) >> 16))
     80 
     81 #define WEBRTC_SPL_SAT(a, b, c)         (b > a ? a : b < c ? c : b)
     82 
     83 // Shifting with negative numbers allowed
     84 // Positive means left shift
     85 #define WEBRTC_SPL_SHIFT_W32(x, c) \
     86     (((c) >= 0) ? ((x) << (c)) : ((x) >> (-(c))))
     87 
     88 // Shifting with negative numbers not allowed
     89 // We cannot do casting here due to signed/unsigned problem
     90 #define WEBRTC_SPL_LSHIFT_W32(x, c)     ((x) << (c))
     91 
     92 #define WEBRTC_SPL_RSHIFT_U32(x, c)     ((uint32_t)(x) >> (c))
     93 
     94 #define WEBRTC_SPL_RAND(a) \
     95     ((int16_t)((((int16_t)a * 18816) >> 7) & 0x00007fff))
     96 
     97 #ifdef __cplusplus
     98 extern "C" {
     99 #endif
    100 
    101 #define WEBRTC_SPL_MEMCPY_W16(v1, v2, length) \
    102   memcpy(v1, v2, (length) * sizeof(int16_t))
    103 
    104 // inline functions:
    105 #include "webrtc/common_audio/signal_processing/include/spl_inl.h"
    106 
    107 // Initialize SPL. Currently it contains only function pointer initialization.
    108 // If the underlying platform is known to be ARM-Neon (WEBRTC_HAS_NEON defined),
    109 // the pointers will be assigned to code optimized for Neon; otherwise
    110 // if run-time Neon detection (WEBRTC_DETECT_NEON) is enabled, the pointers
    111 // will be assigned to either Neon code or generic C code; otherwise, generic C
    112 // code will be assigned.
    113 // Note that this function MUST be called in any application that uses SPL
    114 // functions.
    115 void WebRtcSpl_Init();
    116 
    117 int16_t WebRtcSpl_GetScalingSquare(int16_t* in_vector,
    118                                    size_t in_vector_length,
    119                                    size_t times);
    120 
    121 // Copy and set operations. Implementation in copy_set_operations.c.
    122 // Descriptions at bottom of file.
    123 void WebRtcSpl_MemSetW16(int16_t* vector,
    124                          int16_t set_value,
    125                          size_t vector_length);
    126 void WebRtcSpl_MemSetW32(int32_t* vector,
    127                          int32_t set_value,
    128                          size_t vector_length);
    129 void WebRtcSpl_MemCpyReversedOrder(int16_t* out_vector,
    130                                    int16_t* in_vector,
    131                                    size_t vector_length);
    132 void WebRtcSpl_CopyFromEndW16(const int16_t* in_vector,
    133                               size_t in_vector_length,
    134                               size_t samples,
    135                               int16_t* out_vector);
    136 void WebRtcSpl_ZerosArrayW16(int16_t* vector,
    137                              size_t vector_length);
    138 void WebRtcSpl_ZerosArrayW32(int32_t* vector,
    139                              size_t vector_length);
    140 // End: Copy and set operations.
    141 
    142 
    143 // Minimum and maximum operation functions and their pointers.
    144 // Implementation in min_max_operations.c.
    145 
    146 // Returns the largest absolute value in a signed 16-bit vector.
    147 //
    148 // Input:
    149 //      - vector : 16-bit input vector.
    150 //      - length : Number of samples in vector.
    151 //
    152 // Return value  : Maximum absolute value in vector.
    153 typedef int16_t (*MaxAbsValueW16)(const int16_t* vector, size_t length);
    154 extern MaxAbsValueW16 WebRtcSpl_MaxAbsValueW16;
    155 int16_t WebRtcSpl_MaxAbsValueW16C(const int16_t* vector, size_t length);
    156 #if (defined WEBRTC_DETECT_NEON) || (defined WEBRTC_HAS_NEON)
    157 int16_t WebRtcSpl_MaxAbsValueW16Neon(const int16_t* vector, size_t length);
    158 #endif
    159 #if defined(MIPS32_LE)
    160 int16_t WebRtcSpl_MaxAbsValueW16_mips(const int16_t* vector, size_t length);
    161 #endif
    162 
    163 // Returns the largest absolute value in a signed 32-bit vector.
    164 //
    165 // Input:
    166 //      - vector : 32-bit input vector.
    167 //      - length : Number of samples in vector.
    168 //
    169 // Return value  : Maximum absolute value in vector.
    170 typedef int32_t (*MaxAbsValueW32)(const int32_t* vector, size_t length);
    171 extern MaxAbsValueW32 WebRtcSpl_MaxAbsValueW32;
    172 int32_t WebRtcSpl_MaxAbsValueW32C(const int32_t* vector, size_t length);
    173 #if (defined WEBRTC_DETECT_NEON) || (defined WEBRTC_HAS_NEON)
    174 int32_t WebRtcSpl_MaxAbsValueW32Neon(const int32_t* vector, size_t length);
    175 #endif
    176 #if defined(MIPS_DSP_R1_LE)
    177 int32_t WebRtcSpl_MaxAbsValueW32_mips(const int32_t* vector, size_t length);
    178 #endif
    179 
    180 // Returns the maximum value of a 16-bit vector.
    181 //
    182 // Input:
    183 //      - vector : 16-bit input vector.
    184 //      - length : Number of samples in vector.
    185 //
    186 // Return value  : Maximum sample value in |vector|.
    187 typedef int16_t (*MaxValueW16)(const int16_t* vector, size_t length);
    188 extern MaxValueW16 WebRtcSpl_MaxValueW16;
    189 int16_t WebRtcSpl_MaxValueW16C(const int16_t* vector, size_t length);
    190 #if (defined WEBRTC_DETECT_NEON) || (defined WEBRTC_HAS_NEON)
    191 int16_t WebRtcSpl_MaxValueW16Neon(const int16_t* vector, size_t length);
    192 #endif
    193 #if defined(MIPS32_LE)
    194 int16_t WebRtcSpl_MaxValueW16_mips(const int16_t* vector, size_t length);
    195 #endif
    196 
    197 // Returns the maximum value of a 32-bit vector.
    198 //
    199 // Input:
    200 //      - vector : 32-bit input vector.
    201 //      - length : Number of samples in vector.
    202 //
    203 // Return value  : Maximum sample value in |vector|.
    204 typedef int32_t (*MaxValueW32)(const int32_t* vector, size_t length);
    205 extern MaxValueW32 WebRtcSpl_MaxValueW32;
    206 int32_t WebRtcSpl_MaxValueW32C(const int32_t* vector, size_t length);
    207 #if (defined WEBRTC_DETECT_NEON) || (defined WEBRTC_HAS_NEON)
    208 int32_t WebRtcSpl_MaxValueW32Neon(const int32_t* vector, size_t length);
    209 #endif
    210 #if defined(MIPS32_LE)
    211 int32_t WebRtcSpl_MaxValueW32_mips(const int32_t* vector, size_t length);
    212 #endif
    213 
    214 // Returns the minimum value of a 16-bit vector.
    215 //
    216 // Input:
    217 //      - vector : 16-bit input vector.
    218 //      - length : Number of samples in vector.
    219 //
    220 // Return value  : Minimum sample value in |vector|.
    221 typedef int16_t (*MinValueW16)(const int16_t* vector, size_t length);
    222 extern MinValueW16 WebRtcSpl_MinValueW16;
    223 int16_t WebRtcSpl_MinValueW16C(const int16_t* vector, size_t length);
    224 #if (defined WEBRTC_DETECT_NEON) || (defined WEBRTC_HAS_NEON)
    225 int16_t WebRtcSpl_MinValueW16Neon(const int16_t* vector, size_t length);
    226 #endif
    227 #if defined(MIPS32_LE)
    228 int16_t WebRtcSpl_MinValueW16_mips(const int16_t* vector, size_t length);
    229 #endif
    230 
    231 // Returns the minimum value of a 32-bit vector.
    232 //
    233 // Input:
    234 //      - vector : 32-bit input vector.
    235 //      - length : Number of samples in vector.
    236 //
    237 // Return value  : Minimum sample value in |vector|.
    238 typedef int32_t (*MinValueW32)(const int32_t* vector, size_t length);
    239 extern MinValueW32 WebRtcSpl_MinValueW32;
    240 int32_t WebRtcSpl_MinValueW32C(const int32_t* vector, size_t length);
    241 #if (defined WEBRTC_DETECT_NEON) || (defined WEBRTC_HAS_NEON)
    242 int32_t WebRtcSpl_MinValueW32Neon(const int32_t* vector, size_t length);
    243 #endif
    244 #if defined(MIPS32_LE)
    245 int32_t WebRtcSpl_MinValueW32_mips(const int32_t* vector, size_t length);
    246 #endif
    247 
    248 // Returns the vector index to the largest absolute value of a 16-bit vector.
    249 //
    250 // Input:
    251 //      - vector : 16-bit input vector.
    252 //      - length : Number of samples in vector.
    253 //
    254 // Return value  : Index to the maximum absolute value in vector.
    255 //                 If there are multiple equal maxima, return the index of the
    256 //                 first. -32768 will always have precedence over 32767 (despite
    257 //                 -32768 presenting an int16 absolute value of 32767).
    258 size_t WebRtcSpl_MaxAbsIndexW16(const int16_t* vector, size_t length);
    259 
    260 // Returns the vector index to the maximum sample value of a 16-bit vector.
    261 //
    262 // Input:
    263 //      - vector : 16-bit input vector.
    264 //      - length : Number of samples in vector.
    265 //
    266 // Return value  : Index to the maximum value in vector (if multiple
    267 //                 indexes have the maximum, return the first).
    268 size_t WebRtcSpl_MaxIndexW16(const int16_t* vector, size_t length);
    269 
    270 // Returns the vector index to the maximum sample value of a 32-bit vector.
    271 //
    272 // Input:
    273 //      - vector : 32-bit input vector.
    274 //      - length : Number of samples in vector.
    275 //
    276 // Return value  : Index to the maximum value in vector (if multiple
    277 //                 indexes have the maximum, return the first).
    278 size_t WebRtcSpl_MaxIndexW32(const int32_t* vector, size_t length);
    279 
    280 // Returns the vector index to the minimum sample value of a 16-bit vector.
    281 //
    282 // Input:
    283 //      - vector : 16-bit input vector.
    284 //      - length : Number of samples in vector.
    285 //
    286 // Return value  : Index to the mimimum value in vector  (if multiple
    287 //                 indexes have the minimum, return the first).
    288 size_t WebRtcSpl_MinIndexW16(const int16_t* vector, size_t length);
    289 
    290 // Returns the vector index to the minimum sample value of a 32-bit vector.
    291 //
    292 // Input:
    293 //      - vector : 32-bit input vector.
    294 //      - length : Number of samples in vector.
    295 //
    296 // Return value  : Index to the mimimum value in vector  (if multiple
    297 //                 indexes have the minimum, return the first).
    298 size_t WebRtcSpl_MinIndexW32(const int32_t* vector, size_t length);
    299 
    300 // End: Minimum and maximum operations.
    301 
    302 
    303 // Vector scaling operations. Implementation in vector_scaling_operations.c.
    304 // Description at bottom of file.
    305 void WebRtcSpl_VectorBitShiftW16(int16_t* out_vector,
    306                                  size_t vector_length,
    307                                  const int16_t* in_vector,
    308                                  int16_t right_shifts);
    309 void WebRtcSpl_VectorBitShiftW32(int32_t* out_vector,
    310                                  size_t vector_length,
    311                                  const int32_t* in_vector,
    312                                  int16_t right_shifts);
    313 void WebRtcSpl_VectorBitShiftW32ToW16(int16_t* out_vector,
    314                                       size_t vector_length,
    315                                       const int32_t* in_vector,
    316                                       int right_shifts);
    317 void WebRtcSpl_ScaleVector(const int16_t* in_vector,
    318                            int16_t* out_vector,
    319                            int16_t gain,
    320                            size_t vector_length,
    321                            int16_t right_shifts);
    322 void WebRtcSpl_ScaleVectorWithSat(const int16_t* in_vector,
    323                                   int16_t* out_vector,
    324                                   int16_t gain,
    325                                   size_t vector_length,
    326                                   int16_t right_shifts);
    327 void WebRtcSpl_ScaleAndAddVectors(const int16_t* in_vector1,
    328                                   int16_t gain1, int right_shifts1,
    329                                   const int16_t* in_vector2,
    330                                   int16_t gain2, int right_shifts2,
    331                                   int16_t* out_vector,
    332                                   size_t vector_length);
    333 
    334 // The functions (with related pointer) perform the vector operation:
    335 //   out_vector[k] = ((scale1 * in_vector1[k]) + (scale2 * in_vector2[k])
    336 //        + round_value) >> right_shifts,
    337 //   where  round_value = (1 << right_shifts) >> 1.
    338 //
    339 // Input:
    340 //      - in_vector1       : Input vector 1
    341 //      - in_vector1_scale : Gain to be used for vector 1
    342 //      - in_vector2       : Input vector 2
    343 //      - in_vector2_scale : Gain to be used for vector 2
    344 //      - right_shifts     : Number of right bit shifts to be applied
    345 //      - length           : Number of elements in the input vectors
    346 //
    347 // Output:
    348 //      - out_vector       : Output vector
    349 // Return value            : 0 if OK, -1 if (in_vector1 == NULL
    350 //                           || in_vector2 == NULL || out_vector == NULL
    351 //                           || length <= 0 || right_shift < 0).
    352 typedef int (*ScaleAndAddVectorsWithRound)(const int16_t* in_vector1,
    353                                            int16_t in_vector1_scale,
    354                                            const int16_t* in_vector2,
    355                                            int16_t in_vector2_scale,
    356                                            int right_shifts,
    357                                            int16_t* out_vector,
    358                                            size_t length);
    359 extern ScaleAndAddVectorsWithRound WebRtcSpl_ScaleAndAddVectorsWithRound;
    360 int WebRtcSpl_ScaleAndAddVectorsWithRoundC(const int16_t* in_vector1,
    361                                            int16_t in_vector1_scale,
    362                                            const int16_t* in_vector2,
    363                                            int16_t in_vector2_scale,
    364                                            int right_shifts,
    365                                            int16_t* out_vector,
    366                                            size_t length);
    367 #if defined(MIPS_DSP_R1_LE)
    368 int WebRtcSpl_ScaleAndAddVectorsWithRound_mips(const int16_t* in_vector1,
    369                                                int16_t in_vector1_scale,
    370                                                const int16_t* in_vector2,
    371                                                int16_t in_vector2_scale,
    372                                                int right_shifts,
    373                                                int16_t* out_vector,
    374                                                size_t length);
    375 #endif
    376 // End: Vector scaling operations.
    377 
    378 // iLBC specific functions. Implementations in ilbc_specific_functions.c.
    379 // Description at bottom of file.
    380 void WebRtcSpl_ReverseOrderMultArrayElements(int16_t* out_vector,
    381                                              const int16_t* in_vector,
    382                                              const int16_t* window,
    383                                              size_t vector_length,
    384                                              int16_t right_shifts);
    385 void WebRtcSpl_ElementwiseVectorMult(int16_t* out_vector,
    386                                      const int16_t* in_vector,
    387                                      const int16_t* window,
    388                                      size_t vector_length,
    389                                      int16_t right_shifts);
    390 void WebRtcSpl_AddVectorsAndShift(int16_t* out_vector,
    391                                   const int16_t* in_vector1,
    392                                   const int16_t* in_vector2,
    393                                   size_t vector_length,
    394                                   int16_t right_shifts);
    395 void WebRtcSpl_AddAffineVectorToVector(int16_t* out_vector,
    396                                        int16_t* in_vector,
    397                                        int16_t gain,
    398                                        int32_t add_constant,
    399                                        int16_t right_shifts,
    400                                        size_t vector_length);
    401 void WebRtcSpl_AffineTransformVector(int16_t* out_vector,
    402                                      int16_t* in_vector,
    403                                      int16_t gain,
    404                                      int32_t add_constant,
    405                                      int16_t right_shifts,
    406                                      size_t vector_length);
    407 // End: iLBC specific functions.
    408 
    409 // Signal processing operations.
    410 
    411 // A 32-bit fix-point implementation of auto-correlation computation
    412 //
    413 // Input:
    414 //      - in_vector        : Vector to calculate autocorrelation upon
    415 //      - in_vector_length : Length (in samples) of |vector|
    416 //      - order            : The order up to which the autocorrelation should be
    417 //                           calculated
    418 //
    419 // Output:
    420 //      - result           : auto-correlation values (values should be seen
    421 //                           relative to each other since the absolute values
    422 //                           might have been down shifted to avoid overflow)
    423 //
    424 //      - scale            : The number of left shifts required to obtain the
    425 //                           auto-correlation in Q0
    426 //
    427 // Return value            : Number of samples in |result|, i.e. (order+1)
    428 size_t WebRtcSpl_AutoCorrelation(const int16_t* in_vector,
    429                                  size_t in_vector_length,
    430                                  size_t order,
    431                                  int32_t* result,
    432                                  int* scale);
    433 
    434 // A 32-bit fix-point implementation of the Levinson-Durbin algorithm that
    435 // does NOT use the 64 bit class
    436 //
    437 // Input:
    438 //      - auto_corr : Vector with autocorrelation values of length >= |order|+1
    439 //      - order     : The LPC filter order (support up to order 20)
    440 //
    441 // Output:
    442 //      - lpc_coef  : lpc_coef[0..order] LPC coefficients in Q12
    443 //      - refl_coef : refl_coef[0...order-1]| Reflection coefficients in Q15
    444 //
    445 // Return value     : 1 for stable 0 for unstable
    446 int16_t WebRtcSpl_LevinsonDurbin(const int32_t* auto_corr,
    447                                  int16_t* lpc_coef,
    448                                  int16_t* refl_coef,
    449                                  size_t order);
    450 
    451 // Converts reflection coefficients |refl_coef| to LPC coefficients |lpc_coef|.
    452 // This version is a 16 bit operation.
    453 //
    454 // NOTE: The 16 bit refl_coef -> lpc_coef conversion might result in a
    455 // "slightly unstable" filter (i.e., a pole just outside the unit circle) in
    456 // "rare" cases even if the reflection coefficients are stable.
    457 //
    458 // Input:
    459 //      - refl_coef : Reflection coefficients in Q15 that should be converted
    460 //                    to LPC coefficients
    461 //      - use_order : Number of coefficients in |refl_coef|
    462 //
    463 // Output:
    464 //      - lpc_coef  : LPC coefficients in Q12
    465 void WebRtcSpl_ReflCoefToLpc(const int16_t* refl_coef,
    466                              int use_order,
    467                              int16_t* lpc_coef);
    468 
    469 // Converts LPC coefficients |lpc_coef| to reflection coefficients |refl_coef|.
    470 // This version is a 16 bit operation.
    471 // The conversion is implemented by the step-down algorithm.
    472 //
    473 // Input:
    474 //      - lpc_coef  : LPC coefficients in Q12, that should be converted to
    475 //                    reflection coefficients
    476 //      - use_order : Number of coefficients in |lpc_coef|
    477 //
    478 // Output:
    479 //      - refl_coef : Reflection coefficients in Q15.
    480 void WebRtcSpl_LpcToReflCoef(int16_t* lpc_coef,
    481                              int use_order,
    482                              int16_t* refl_coef);
    483 
    484 // Calculates reflection coefficients (16 bit) from auto-correlation values
    485 //
    486 // Input:
    487 //      - auto_corr : Auto-correlation values
    488 //      - use_order : Number of coefficients wanted be calculated
    489 //
    490 // Output:
    491 //      - refl_coef : Reflection coefficients in Q15.
    492 void WebRtcSpl_AutoCorrToReflCoef(const int32_t* auto_corr,
    493                                   int use_order,
    494                                   int16_t* refl_coef);
    495 
    496 // The functions (with related pointer) calculate the cross-correlation between
    497 // two sequences |seq1| and |seq2|.
    498 // |seq1| is fixed and |seq2| slides as the pointer is increased with the
    499 // amount |step_seq2|. Note the arguments should obey the relationship:
    500 // |dim_seq| - 1 + |step_seq2| * (|dim_cross_correlation| - 1) <
    501 //      buffer size of |seq2|
    502 //
    503 // Input:
    504 //      - seq1           : First sequence (fixed throughout the correlation)
    505 //      - seq2           : Second sequence (slides |step_vector2| for each
    506 //                            new correlation)
    507 //      - dim_seq        : Number of samples to use in the cross-correlation
    508 //      - dim_cross_correlation : Number of cross-correlations to calculate (the
    509 //                            start position for |vector2| is updated for each
    510 //                            new one)
    511 //      - right_shifts   : Number of right bit shifts to use. This will
    512 //                            become the output Q-domain.
    513 //      - step_seq2      : How many (positive or negative) steps the
    514 //                            |vector2| pointer should be updated for each new
    515 //                            cross-correlation value.
    516 //
    517 // Output:
    518 //      - cross_correlation : The cross-correlation in Q(-right_shifts)
    519 typedef void (*CrossCorrelation)(int32_t* cross_correlation,
    520                                  const int16_t* seq1,
    521                                  const int16_t* seq2,
    522                                  size_t dim_seq,
    523                                  size_t dim_cross_correlation,
    524                                  int right_shifts,
    525                                  int step_seq2);
    526 extern CrossCorrelation WebRtcSpl_CrossCorrelation;
    527 void WebRtcSpl_CrossCorrelationC(int32_t* cross_correlation,
    528                                  const int16_t* seq1,
    529                                  const int16_t* seq2,
    530                                  size_t dim_seq,
    531                                  size_t dim_cross_correlation,
    532                                  int right_shifts,
    533                                  int step_seq2);
    534 #if (defined WEBRTC_DETECT_NEON) || (defined WEBRTC_HAS_NEON)
    535 void WebRtcSpl_CrossCorrelationNeon(int32_t* cross_correlation,
    536                                     const int16_t* seq1,
    537                                     const int16_t* seq2,
    538                                     size_t dim_seq,
    539                                     size_t dim_cross_correlation,
    540                                     int right_shifts,
    541                                     int step_seq2);
    542 #endif
    543 #if defined(MIPS32_LE)
    544 void WebRtcSpl_CrossCorrelation_mips(int32_t* cross_correlation,
    545                                      const int16_t* seq1,
    546                                      const int16_t* seq2,
    547                                      size_t dim_seq,
    548                                      size_t dim_cross_correlation,
    549                                      int right_shifts,
    550                                      int step_seq2);
    551 #endif
    552 
    553 // Creates (the first half of) a Hanning window. Size must be at least 1 and
    554 // at most 512.
    555 //
    556 // Input:
    557 //      - size      : Length of the requested Hanning window (1 to 512)
    558 //
    559 // Output:
    560 //      - window    : Hanning vector in Q14.
    561 void WebRtcSpl_GetHanningWindow(int16_t* window, size_t size);
    562 
    563 // Calculates y[k] = sqrt(1 - x[k]^2) for each element of the input vector
    564 // |in_vector|. Input and output values are in Q15.
    565 //
    566 // Inputs:
    567 //      - in_vector     : Values to calculate sqrt(1 - x^2) of
    568 //      - vector_length : Length of vector |in_vector|
    569 //
    570 // Output:
    571 //      - out_vector    : Output values in Q15
    572 void WebRtcSpl_SqrtOfOneMinusXSquared(int16_t* in_vector,
    573                                       size_t vector_length,
    574                                       int16_t* out_vector);
    575 // End: Signal processing operations.
    576 
    577 // Randomization functions. Implementations collected in
    578 // randomization_functions.c and descriptions at bottom of this file.
    579 int16_t WebRtcSpl_RandU(uint32_t* seed);
    580 int16_t WebRtcSpl_RandN(uint32_t* seed);
    581 int16_t WebRtcSpl_RandUArray(int16_t* vector,
    582                              int16_t vector_length,
    583                              uint32_t* seed);
    584 // End: Randomization functions.
    585 
    586 // Math functions
    587 int32_t WebRtcSpl_Sqrt(int32_t value);
    588 int32_t WebRtcSpl_SqrtFloor(int32_t value);
    589 
    590 // Divisions. Implementations collected in division_operations.c and
    591 // descriptions at bottom of this file.
    592 uint32_t WebRtcSpl_DivU32U16(uint32_t num, uint16_t den);
    593 int32_t WebRtcSpl_DivW32W16(int32_t num, int16_t den);
    594 int16_t WebRtcSpl_DivW32W16ResW16(int32_t num, int16_t den);
    595 int32_t WebRtcSpl_DivResultInQ31(int32_t num, int32_t den);
    596 int32_t WebRtcSpl_DivW32HiLow(int32_t num, int16_t den_hi, int16_t den_low);
    597 // End: Divisions.
    598 
    599 int32_t WebRtcSpl_Energy(int16_t* vector,
    600                          size_t vector_length,
    601                          int* scale_factor);
    602 
    603 // Calculates the dot product between two (int16_t) vectors.
    604 //
    605 // Input:
    606 //      - vector1       : Vector 1
    607 //      - vector2       : Vector 2
    608 //      - vector_length : Number of samples used in the dot product
    609 //      - scaling       : The number of right bit shifts to apply on each term
    610 //                        during calculation to avoid overflow, i.e., the
    611 //                        output will be in Q(-|scaling|)
    612 //
    613 // Return value         : The dot product in Q(-scaling)
    614 int32_t WebRtcSpl_DotProductWithScale(const int16_t* vector1,
    615                                       const int16_t* vector2,
    616                                       size_t length,
    617                                       int scaling);
    618 
    619 // Filter operations.
    620 size_t WebRtcSpl_FilterAR(const int16_t* ar_coef,
    621                           size_t ar_coef_length,
    622                           const int16_t* in_vector,
    623                           size_t in_vector_length,
    624                           int16_t* filter_state,
    625                           size_t filter_state_length,
    626                           int16_t* filter_state_low,
    627                           size_t filter_state_low_length,
    628                           int16_t* out_vector,
    629                           int16_t* out_vector_low,
    630                           size_t out_vector_low_length);
    631 
    632 // WebRtcSpl_FilterMAFastQ12(...)
    633 //
    634 // Performs a MA filtering on a vector in Q12
    635 //
    636 // Input:
    637 //      - in_vector         : Input samples (state in positions
    638 //                            in_vector[-order] .. in_vector[-1])
    639 //      - ma_coef           : Filter coefficients (in Q12)
    640 //      - ma_coef_length    : Number of B coefficients (order+1)
    641 //      - vector_length     : Number of samples to be filtered
    642 //
    643 // Output:
    644 //      - out_vector        : Filtered samples
    645 //
    646 void WebRtcSpl_FilterMAFastQ12(const int16_t* in_vector,
    647                                int16_t* out_vector,
    648                                const int16_t* ma_coef,
    649                                size_t ma_coef_length,
    650                                size_t vector_length);
    651 
    652 // Performs a AR filtering on a vector in Q12
    653 // Input:
    654 //      - data_in            : Input samples
    655 //      - data_out           : State information in positions
    656 //                               data_out[-order] .. data_out[-1]
    657 //      - coefficients       : Filter coefficients (in Q12)
    658 //      - coefficients_length: Number of coefficients (order+1)
    659 //      - data_length        : Number of samples to be filtered
    660 // Output:
    661 //      - data_out           : Filtered samples
    662 void WebRtcSpl_FilterARFastQ12(const int16_t* data_in,
    663                                int16_t* data_out,
    664                                const int16_t* __restrict coefficients,
    665                                size_t coefficients_length,
    666                                size_t data_length);
    667 
    668 // The functions (with related pointer) perform a MA down sampling filter
    669 // on a vector.
    670 // Input:
    671 //      - data_in            : Input samples (state in positions
    672 //                               data_in[-order] .. data_in[-1])
    673 //      - data_in_length     : Number of samples in |data_in| to be filtered.
    674 //                               This must be at least
    675 //                               |delay| + |factor|*(|out_vector_length|-1) + 1)
    676 //      - data_out_length    : Number of down sampled samples desired
    677 //      - coefficients       : Filter coefficients (in Q12)
    678 //      - coefficients_length: Number of coefficients (order+1)
    679 //      - factor             : Decimation factor
    680 //      - delay              : Delay of filter (compensated for in out_vector)
    681 // Output:
    682 //      - data_out           : Filtered samples
    683 // Return value              : 0 if OK, -1 if |in_vector| is too short
    684 typedef int (*DownsampleFast)(const int16_t* data_in,
    685                               size_t data_in_length,
    686                               int16_t* data_out,
    687                               size_t data_out_length,
    688                               const int16_t* __restrict coefficients,
    689                               size_t coefficients_length,
    690                               int factor,
    691                               size_t delay);
    692 extern DownsampleFast WebRtcSpl_DownsampleFast;
    693 int WebRtcSpl_DownsampleFastC(const int16_t* data_in,
    694                               size_t data_in_length,
    695                               int16_t* data_out,
    696                               size_t data_out_length,
    697                               const int16_t* __restrict coefficients,
    698                               size_t coefficients_length,
    699                               int factor,
    700                               size_t delay);
    701 #if (defined WEBRTC_DETECT_NEON) || (defined WEBRTC_HAS_NEON)
    702 int WebRtcSpl_DownsampleFastNeon(const int16_t* data_in,
    703                                  size_t data_in_length,
    704                                  int16_t* data_out,
    705                                  size_t data_out_length,
    706                                  const int16_t* __restrict coefficients,
    707                                  size_t coefficients_length,
    708                                  int factor,
    709                                  size_t delay);
    710 #endif
    711 #if defined(MIPS32_LE)
    712 int WebRtcSpl_DownsampleFast_mips(const int16_t* data_in,
    713                                   size_t data_in_length,
    714                                   int16_t* data_out,
    715                                   size_t data_out_length,
    716                                   const int16_t* __restrict coefficients,
    717                                   size_t coefficients_length,
    718                                   int factor,
    719                                   size_t delay);
    720 #endif
    721 
    722 // End: Filter operations.
    723 
    724 // FFT operations
    725 
    726 int WebRtcSpl_ComplexFFT(int16_t vector[], int stages, int mode);
    727 int WebRtcSpl_ComplexIFFT(int16_t vector[], int stages, int mode);
    728 
    729 // Treat a 16-bit complex data buffer |complex_data| as an array of 32-bit
    730 // values, and swap elements whose indexes are bit-reverses of each other.
    731 //
    732 // Input:
    733 //      - complex_data  : Complex data buffer containing 2^|stages| real
    734 //                        elements interleaved with 2^|stages| imaginary
    735 //                        elements: [Re Im Re Im Re Im....]
    736 //      - stages        : Number of FFT stages. Must be at least 3 and at most
    737 //                        10, since the table WebRtcSpl_kSinTable1024[] is 1024
    738 //                        elements long.
    739 //
    740 // Output:
    741 //      - complex_data  : The complex data buffer.
    742 
    743 void WebRtcSpl_ComplexBitReverse(int16_t* __restrict complex_data, int stages);
    744 
    745 // End: FFT operations
    746 
    747 /************************************************************
    748  *
    749  * RESAMPLING FUNCTIONS AND THEIR STRUCTS ARE DEFINED BELOW
    750  *
    751  ************************************************************/
    752 
    753 /*******************************************************************
    754  * resample.c
    755  *
    756  * Includes the following resampling combinations
    757  * 22 kHz -> 16 kHz
    758  * 16 kHz -> 22 kHz
    759  * 22 kHz ->  8 kHz
    760  *  8 kHz -> 22 kHz
    761  *
    762  ******************************************************************/
    763 
    764 // state structure for 22 -> 16 resampler
    765 typedef struct {
    766   int32_t S_22_44[8];
    767   int32_t S_44_32[8];
    768   int32_t S_32_16[8];
    769 } WebRtcSpl_State22khzTo16khz;
    770 
    771 void WebRtcSpl_Resample22khzTo16khz(const int16_t* in,
    772                                     int16_t* out,
    773                                     WebRtcSpl_State22khzTo16khz* state,
    774                                     int32_t* tmpmem);
    775 
    776 void WebRtcSpl_ResetResample22khzTo16khz(WebRtcSpl_State22khzTo16khz* state);
    777 
    778 // state structure for 16 -> 22 resampler
    779 typedef struct {
    780   int32_t S_16_32[8];
    781   int32_t S_32_22[8];
    782 } WebRtcSpl_State16khzTo22khz;
    783 
    784 void WebRtcSpl_Resample16khzTo22khz(const int16_t* in,
    785                                     int16_t* out,
    786                                     WebRtcSpl_State16khzTo22khz* state,
    787                                     int32_t* tmpmem);
    788 
    789 void WebRtcSpl_ResetResample16khzTo22khz(WebRtcSpl_State16khzTo22khz* state);
    790 
    791 // state structure for 22 -> 8 resampler
    792 typedef struct {
    793   int32_t S_22_22[16];
    794   int32_t S_22_16[8];
    795   int32_t S_16_8[8];
    796 } WebRtcSpl_State22khzTo8khz;
    797 
    798 void WebRtcSpl_Resample22khzTo8khz(const int16_t* in, int16_t* out,
    799                                    WebRtcSpl_State22khzTo8khz* state,
    800                                    int32_t* tmpmem);
    801 
    802 void WebRtcSpl_ResetResample22khzTo8khz(WebRtcSpl_State22khzTo8khz* state);
    803 
    804 // state structure for 8 -> 22 resampler
    805 typedef struct {
    806   int32_t S_8_16[8];
    807   int32_t S_16_11[8];
    808   int32_t S_11_22[8];
    809 } WebRtcSpl_State8khzTo22khz;
    810 
    811 void WebRtcSpl_Resample8khzTo22khz(const int16_t* in, int16_t* out,
    812                                    WebRtcSpl_State8khzTo22khz* state,
    813                                    int32_t* tmpmem);
    814 
    815 void WebRtcSpl_ResetResample8khzTo22khz(WebRtcSpl_State8khzTo22khz* state);
    816 
    817 /*******************************************************************
    818  * resample_fractional.c
    819  * Functions for internal use in the other resample functions
    820  *
    821  * Includes the following resampling combinations
    822  * 48 kHz -> 32 kHz
    823  * 32 kHz -> 24 kHz
    824  * 44 kHz -> 32 kHz
    825  *
    826  ******************************************************************/
    827 
    828 void WebRtcSpl_Resample48khzTo32khz(const int32_t* In, int32_t* Out, size_t K);
    829 
    830 void WebRtcSpl_Resample32khzTo24khz(const int32_t* In, int32_t* Out, size_t K);
    831 
    832 void WebRtcSpl_Resample44khzTo32khz(const int32_t* In, int32_t* Out, size_t K);
    833 
    834 /*******************************************************************
    835  * resample_48khz.c
    836  *
    837  * Includes the following resampling combinations
    838  * 48 kHz -> 16 kHz
    839  * 16 kHz -> 48 kHz
    840  * 48 kHz ->  8 kHz
    841  *  8 kHz -> 48 kHz
    842  *
    843  ******************************************************************/
    844 
    845 typedef struct {
    846   int32_t S_48_48[16];
    847   int32_t S_48_32[8];
    848   int32_t S_32_16[8];
    849 } WebRtcSpl_State48khzTo16khz;
    850 
    851 void WebRtcSpl_Resample48khzTo16khz(const int16_t* in, int16_t* out,
    852                                     WebRtcSpl_State48khzTo16khz* state,
    853                                     int32_t* tmpmem);
    854 
    855 void WebRtcSpl_ResetResample48khzTo16khz(WebRtcSpl_State48khzTo16khz* state);
    856 
    857 typedef struct {
    858   int32_t S_16_32[8];
    859   int32_t S_32_24[8];
    860   int32_t S_24_48[8];
    861 } WebRtcSpl_State16khzTo48khz;
    862 
    863 void WebRtcSpl_Resample16khzTo48khz(const int16_t* in, int16_t* out,
    864                                     WebRtcSpl_State16khzTo48khz* state,
    865                                     int32_t* tmpmem);
    866 
    867 void WebRtcSpl_ResetResample16khzTo48khz(WebRtcSpl_State16khzTo48khz* state);
    868 
    869 typedef struct {
    870   int32_t S_48_24[8];
    871   int32_t S_24_24[16];
    872   int32_t S_24_16[8];
    873   int32_t S_16_8[8];
    874 } WebRtcSpl_State48khzTo8khz;
    875 
    876 void WebRtcSpl_Resample48khzTo8khz(const int16_t* in, int16_t* out,
    877                                    WebRtcSpl_State48khzTo8khz* state,
    878                                    int32_t* tmpmem);
    879 
    880 void WebRtcSpl_ResetResample48khzTo8khz(WebRtcSpl_State48khzTo8khz* state);
    881 
    882 typedef struct {
    883   int32_t S_8_16[8];
    884   int32_t S_16_12[8];
    885   int32_t S_12_24[8];
    886   int32_t S_24_48[8];
    887 } WebRtcSpl_State8khzTo48khz;
    888 
    889 void WebRtcSpl_Resample8khzTo48khz(const int16_t* in, int16_t* out,
    890                                    WebRtcSpl_State8khzTo48khz* state,
    891                                    int32_t* tmpmem);
    892 
    893 void WebRtcSpl_ResetResample8khzTo48khz(WebRtcSpl_State8khzTo48khz* state);
    894 
    895 /*******************************************************************
    896  * resample_by_2.c
    897  *
    898  * Includes down and up sampling by a factor of two.
    899  *
    900  ******************************************************************/
    901 
    902 void WebRtcSpl_DownsampleBy2(const int16_t* in, size_t len,
    903                              int16_t* out, int32_t* filtState);
    904 
    905 void WebRtcSpl_UpsampleBy2(const int16_t* in, size_t len,
    906                            int16_t* out, int32_t* filtState);
    907 
    908 /************************************************************
    909  * END OF RESAMPLING FUNCTIONS
    910  ************************************************************/
    911 void WebRtcSpl_AnalysisQMF(const int16_t* in_data,
    912                            size_t in_data_length,
    913                            int16_t* low_band,
    914                            int16_t* high_band,
    915                            int32_t* filter_state1,
    916                            int32_t* filter_state2);
    917 void WebRtcSpl_SynthesisQMF(const int16_t* low_band,
    918                             const int16_t* high_band,
    919                             size_t band_length,
    920                             int16_t* out_data,
    921                             int32_t* filter_state1,
    922                             int32_t* filter_state2);
    923 
    924 #ifdef __cplusplus
    925 }
    926 #endif  // __cplusplus
    927 #endif  // WEBRTC_SPL_SIGNAL_PROCESSING_LIBRARY_H_
    928 
    929 //
    930 // WebRtcSpl_AddSatW16(...)
    931 // WebRtcSpl_AddSatW32(...)
    932 //
    933 // Returns the result of a saturated 16-bit, respectively 32-bit, addition of
    934 // the numbers specified by the |var1| and |var2| parameters.
    935 //
    936 // Input:
    937 //      - var1      : Input variable 1
    938 //      - var2      : Input variable 2
    939 //
    940 // Return value     : Added and saturated value
    941 //
    942 
    943 //
    944 // WebRtcSpl_SubSatW16(...)
    945 // WebRtcSpl_SubSatW32(...)
    946 //
    947 // Returns the result of a saturated 16-bit, respectively 32-bit, subtraction
    948 // of the numbers specified by the |var1| and |var2| parameters.
    949 //
    950 // Input:
    951 //      - var1      : Input variable 1
    952 //      - var2      : Input variable 2
    953 //
    954 // Returned value   : Subtracted and saturated value
    955 //
    956 
    957 //
    958 // WebRtcSpl_GetSizeInBits(...)
    959 //
    960 // Returns the # of bits that are needed at the most to represent the number
    961 // specified by the |value| parameter.
    962 //
    963 // Input:
    964 //      - value     : Input value
    965 //
    966 // Return value     : Number of bits needed to represent |value|
    967 //
    968 
    969 //
    970 // WebRtcSpl_NormW32(...)
    971 //
    972 // Norm returns the # of left shifts required to 32-bit normalize the 32-bit
    973 // signed number specified by the |value| parameter.
    974 //
    975 // Input:
    976 //      - value     : Input value
    977 //
    978 // Return value     : Number of bit shifts needed to 32-bit normalize |value|
    979 //
    980 
    981 //
    982 // WebRtcSpl_NormW16(...)
    983 //
    984 // Norm returns the # of left shifts required to 16-bit normalize the 16-bit
    985 // signed number specified by the |value| parameter.
    986 //
    987 // Input:
    988 //      - value     : Input value
    989 //
    990 // Return value     : Number of bit shifts needed to 32-bit normalize |value|
    991 //
    992 
    993 //
    994 // WebRtcSpl_NormU32(...)
    995 //
    996 // Norm returns the # of left shifts required to 32-bit normalize the unsigned
    997 // 32-bit number specified by the |value| parameter.
    998 //
    999 // Input:
   1000 //      - value     : Input value
   1001 //
   1002 // Return value     : Number of bit shifts needed to 32-bit normalize |value|
   1003 //
   1004 
   1005 //
   1006 // WebRtcSpl_GetScalingSquare(...)
   1007 //
   1008 // Returns the # of bits required to scale the samples specified in the
   1009 // |in_vector| parameter so that, if the squares of the samples are added the
   1010 // # of times specified by the |times| parameter, the 32-bit addition will not
   1011 // overflow (result in int32_t).
   1012 //
   1013 // Input:
   1014 //      - in_vector         : Input vector to check scaling on
   1015 //      - in_vector_length  : Samples in |in_vector|
   1016 //      - times             : Number of additions to be performed
   1017 //
   1018 // Return value             : Number of right bit shifts needed to avoid
   1019 //                            overflow in the addition calculation
   1020 //
   1021 
   1022 //
   1023 // WebRtcSpl_MemSetW16(...)
   1024 //
   1025 // Sets all the values in the int16_t vector |vector| of length
   1026 // |vector_length| to the specified value |set_value|
   1027 //
   1028 // Input:
   1029 //      - vector        : Pointer to the int16_t vector
   1030 //      - set_value     : Value specified
   1031 //      - vector_length : Length of vector
   1032 //
   1033 
   1034 //
   1035 // WebRtcSpl_MemSetW32(...)
   1036 //
   1037 // Sets all the values in the int32_t vector |vector| of length
   1038 // |vector_length| to the specified value |set_value|
   1039 //
   1040 // Input:
   1041 //      - vector        : Pointer to the int16_t vector
   1042 //      - set_value     : Value specified
   1043 //      - vector_length : Length of vector
   1044 //
   1045 
   1046 //
   1047 // WebRtcSpl_MemCpyReversedOrder(...)
   1048 //
   1049 // Copies all the values from the source int16_t vector |in_vector| to a
   1050 // destination int16_t vector |out_vector|. It is done in reversed order,
   1051 // meaning that the first sample of |in_vector| is copied to the last sample of
   1052 // the |out_vector|. The procedure continues until the last sample of
   1053 // |in_vector| has been copied to the first sample of |out_vector|. This
   1054 // creates a reversed vector. Used in e.g. prediction in iLBC.
   1055 //
   1056 // Input:
   1057 //      - in_vector     : Pointer to the first sample in a int16_t vector
   1058 //                        of length |length|
   1059 //      - vector_length : Number of elements to copy
   1060 //
   1061 // Output:
   1062 //      - out_vector    : Pointer to the last sample in a int16_t vector
   1063 //                        of length |length|
   1064 //
   1065 
   1066 //
   1067 // WebRtcSpl_CopyFromEndW16(...)
   1068 //
   1069 // Copies the rightmost |samples| of |in_vector| (of length |in_vector_length|)
   1070 // to the vector |out_vector|.
   1071 //
   1072 // Input:
   1073 //      - in_vector         : Input vector
   1074 //      - in_vector_length  : Number of samples in |in_vector|
   1075 //      - samples           : Number of samples to extract (from right side)
   1076 //                            from |in_vector|
   1077 //
   1078 // Output:
   1079 //      - out_vector        : Vector with the requested samples
   1080 //
   1081 
   1082 //
   1083 // WebRtcSpl_ZerosArrayW16(...)
   1084 // WebRtcSpl_ZerosArrayW32(...)
   1085 //
   1086 // Inserts the value "zero" in all positions of a w16 and a w32 vector
   1087 // respectively.
   1088 //
   1089 // Input:
   1090 //      - vector_length : Number of samples in vector
   1091 //
   1092 // Output:
   1093 //      - vector        : Vector containing all zeros
   1094 //
   1095 
   1096 //
   1097 // WebRtcSpl_VectorBitShiftW16(...)
   1098 // WebRtcSpl_VectorBitShiftW32(...)
   1099 //
   1100 // Bit shifts all the values in a vector up or downwards. Different calls for
   1101 // int16_t and int32_t vectors respectively.
   1102 //
   1103 // Input:
   1104 //      - vector_length : Length of vector
   1105 //      - in_vector     : Pointer to the vector that should be bit shifted
   1106 //      - right_shifts  : Number of right bit shifts (negative value gives left
   1107 //                        shifts)
   1108 //
   1109 // Output:
   1110 //      - out_vector    : Pointer to the result vector (can be the same as
   1111 //                        |in_vector|)
   1112 //
   1113 
   1114 //
   1115 // WebRtcSpl_VectorBitShiftW32ToW16(...)
   1116 //
   1117 // Bit shifts all the values in a int32_t vector up or downwards and
   1118 // stores the result as an int16_t vector. The function will saturate the
   1119 // signal if needed, before storing in the output vector.
   1120 //
   1121 // Input:
   1122 //      - vector_length : Length of vector
   1123 //      - in_vector     : Pointer to the vector that should be bit shifted
   1124 //      - right_shifts  : Number of right bit shifts (negative value gives left
   1125 //                        shifts)
   1126 //
   1127 // Output:
   1128 //      - out_vector    : Pointer to the result vector (can be the same as
   1129 //                        |in_vector|)
   1130 //
   1131 
   1132 //
   1133 // WebRtcSpl_ScaleVector(...)
   1134 //
   1135 // Performs the vector operation:
   1136 //  out_vector[k] = (gain*in_vector[k])>>right_shifts
   1137 //
   1138 // Input:
   1139 //      - in_vector     : Input vector
   1140 //      - gain          : Scaling gain
   1141 //      - vector_length : Elements in the |in_vector|
   1142 //      - right_shifts  : Number of right bit shifts applied
   1143 //
   1144 // Output:
   1145 //      - out_vector    : Output vector (can be the same as |in_vector|)
   1146 //
   1147 
   1148 //
   1149 // WebRtcSpl_ScaleVectorWithSat(...)
   1150 //
   1151 // Performs the vector operation:
   1152 //  out_vector[k] = SATURATE( (gain*in_vector[k])>>right_shifts )
   1153 //
   1154 // Input:
   1155 //      - in_vector     : Input vector
   1156 //      - gain          : Scaling gain
   1157 //      - vector_length : Elements in the |in_vector|
   1158 //      - right_shifts  : Number of right bit shifts applied
   1159 //
   1160 // Output:
   1161 //      - out_vector    : Output vector (can be the same as |in_vector|)
   1162 //
   1163 
   1164 //
   1165 // WebRtcSpl_ScaleAndAddVectors(...)
   1166 //
   1167 // Performs the vector operation:
   1168 //  out_vector[k] = (gain1*in_vector1[k])>>right_shifts1
   1169 //                  + (gain2*in_vector2[k])>>right_shifts2
   1170 //
   1171 // Input:
   1172 //      - in_vector1    : Input vector 1
   1173 //      - gain1         : Gain to be used for vector 1
   1174 //      - right_shifts1 : Right bit shift to be used for vector 1
   1175 //      - in_vector2    : Input vector 2
   1176 //      - gain2         : Gain to be used for vector 2
   1177 //      - right_shifts2 : Right bit shift to be used for vector 2
   1178 //      - vector_length : Elements in the input vectors
   1179 //
   1180 // Output:
   1181 //      - out_vector    : Output vector
   1182 //
   1183 
   1184 //
   1185 // WebRtcSpl_ReverseOrderMultArrayElements(...)
   1186 //
   1187 // Performs the vector operation:
   1188 //  out_vector[n] = (in_vector[n]*window[-n])>>right_shifts
   1189 //
   1190 // Input:
   1191 //      - in_vector     : Input vector
   1192 //      - window        : Window vector (should be reversed). The pointer
   1193 //                        should be set to the last value in the vector
   1194 //      - right_shifts  : Number of right bit shift to be applied after the
   1195 //                        multiplication
   1196 //      - vector_length : Number of elements in |in_vector|
   1197 //
   1198 // Output:
   1199 //      - out_vector    : Output vector (can be same as |in_vector|)
   1200 //
   1201 
   1202 //
   1203 // WebRtcSpl_ElementwiseVectorMult(...)
   1204 //
   1205 // Performs the vector operation:
   1206 //  out_vector[n] = (in_vector[n]*window[n])>>right_shifts
   1207 //
   1208 // Input:
   1209 //      - in_vector     : Input vector
   1210 //      - window        : Window vector.
   1211 //      - right_shifts  : Number of right bit shift to be applied after the
   1212 //                        multiplication
   1213 //      - vector_length : Number of elements in |in_vector|
   1214 //
   1215 // Output:
   1216 //      - out_vector    : Output vector (can be same as |in_vector|)
   1217 //
   1218 
   1219 //
   1220 // WebRtcSpl_AddVectorsAndShift(...)
   1221 //
   1222 // Performs the vector operation:
   1223 //  out_vector[k] = (in_vector1[k] + in_vector2[k])>>right_shifts
   1224 //
   1225 // Input:
   1226 //      - in_vector1    : Input vector 1
   1227 //      - in_vector2    : Input vector 2
   1228 //      - right_shifts  : Number of right bit shift to be applied after the
   1229 //                        multiplication
   1230 //      - vector_length : Number of elements in |in_vector1| and |in_vector2|
   1231 //
   1232 // Output:
   1233 //      - out_vector    : Output vector (can be same as |in_vector1|)
   1234 //
   1235 
   1236 //
   1237 // WebRtcSpl_AddAffineVectorToVector(...)
   1238 //
   1239 // Adds an affine transformed vector to another vector |out_vector|, i.e,
   1240 // performs
   1241 //  out_vector[k] += (in_vector[k]*gain+add_constant)>>right_shifts
   1242 //
   1243 // Input:
   1244 //      - in_vector     : Input vector
   1245 //      - gain          : Gain value, used to multiply the in vector with
   1246 //      - add_constant  : Constant value to add (usually 1<<(right_shifts-1),
   1247 //                        but others can be used as well
   1248 //      - right_shifts  : Number of right bit shifts (0-16)
   1249 //      - vector_length : Number of samples in |in_vector| and |out_vector|
   1250 //
   1251 // Output:
   1252 //      - out_vector    : Vector with the output
   1253 //
   1254 
   1255 //
   1256 // WebRtcSpl_AffineTransformVector(...)
   1257 //
   1258 // Affine transforms a vector, i.e, performs
   1259 //  out_vector[k] = (in_vector[k]*gain+add_constant)>>right_shifts
   1260 //
   1261 // Input:
   1262 //      - in_vector     : Input vector
   1263 //      - gain          : Gain value, used to multiply the in vector with
   1264 //      - add_constant  : Constant value to add (usually 1<<(right_shifts-1),
   1265 //                        but others can be used as well
   1266 //      - right_shifts  : Number of right bit shifts (0-16)
   1267 //      - vector_length : Number of samples in |in_vector| and |out_vector|
   1268 //
   1269 // Output:
   1270 //      - out_vector    : Vector with the output
   1271 //
   1272 
   1273 //
   1274 // WebRtcSpl_IncreaseSeed(...)
   1275 //
   1276 // Increases the seed (and returns the new value)
   1277 //
   1278 // Input:
   1279 //      - seed      : Seed for random calculation
   1280 //
   1281 // Output:
   1282 //      - seed      : Updated seed value
   1283 //
   1284 // Return value     : The new seed value
   1285 //
   1286 
   1287 //
   1288 // WebRtcSpl_RandU(...)
   1289 //
   1290 // Produces a uniformly distributed value in the int16_t range
   1291 //
   1292 // Input:
   1293 //      - seed      : Seed for random calculation
   1294 //
   1295 // Output:
   1296 //      - seed      : Updated seed value
   1297 //
   1298 // Return value     : Uniformly distributed value in the range
   1299 //                    [Word16_MIN...Word16_MAX]
   1300 //
   1301 
   1302 //
   1303 // WebRtcSpl_RandN(...)
   1304 //
   1305 // Produces a normal distributed value in the int16_t range
   1306 //
   1307 // Input:
   1308 //      - seed      : Seed for random calculation
   1309 //
   1310 // Output:
   1311 //      - seed      : Updated seed value
   1312 //
   1313 // Return value     : N(0,1) value in the Q13 domain
   1314 //
   1315 
   1316 //
   1317 // WebRtcSpl_RandUArray(...)
   1318 //
   1319 // Produces a uniformly distributed vector with elements in the int16_t
   1320 // range
   1321 //
   1322 // Input:
   1323 //      - vector_length : Samples wanted in the vector
   1324 //      - seed          : Seed for random calculation
   1325 //
   1326 // Output:
   1327 //      - vector        : Vector with the uniform values
   1328 //      - seed          : Updated seed value
   1329 //
   1330 // Return value         : Number of samples in vector, i.e., |vector_length|
   1331 //
   1332 
   1333 //
   1334 // WebRtcSpl_Sqrt(...)
   1335 //
   1336 // Returns the square root of the input value |value|. The precision of this
   1337 // function is integer precision, i.e., sqrt(8) gives 2 as answer.
   1338 // If |value| is a negative number then 0 is returned.
   1339 //
   1340 // Algorithm:
   1341 //
   1342 // A sixth order Taylor Series expansion is used here to compute the square
   1343 // root of a number y^0.5 = (1+x)^0.5
   1344 // where
   1345 // x = y-1
   1346 //   = 1+(x/2)-0.5*((x/2)^2+0.5*((x/2)^3-0.625*((x/2)^4+0.875*((x/2)^5)
   1347 // 0.5 <= x < 1
   1348 //
   1349 // Input:
   1350 //      - value     : Value to calculate sqrt of
   1351 //
   1352 // Return value     : Result of the sqrt calculation
   1353 //
   1354 
   1355 //
   1356 // WebRtcSpl_SqrtFloor(...)
   1357 //
   1358 // Returns the square root of the input value |value|. The precision of this
   1359 // function is rounding down integer precision, i.e., sqrt(8) gives 2 as answer.
   1360 // If |value| is a negative number then 0 is returned.
   1361 //
   1362 // Algorithm:
   1363 //
   1364 // An iterative 4 cylce/bit routine
   1365 //
   1366 // Input:
   1367 //      - value     : Value to calculate sqrt of
   1368 //
   1369 // Return value     : Result of the sqrt calculation
   1370 //
   1371 
   1372 //
   1373 // WebRtcSpl_DivU32U16(...)
   1374 //
   1375 // Divides a uint32_t |num| by a uint16_t |den|.
   1376 //
   1377 // If |den|==0, (uint32_t)0xFFFFFFFF is returned.
   1378 //
   1379 // Input:
   1380 //      - num       : Numerator
   1381 //      - den       : Denominator
   1382 //
   1383 // Return value     : Result of the division (as a uint32_t), i.e., the
   1384 //                    integer part of num/den.
   1385 //
   1386 
   1387 //
   1388 // WebRtcSpl_DivW32W16(...)
   1389 //
   1390 // Divides a int32_t |num| by a int16_t |den|.
   1391 //
   1392 // If |den|==0, (int32_t)0x7FFFFFFF is returned.
   1393 //
   1394 // Input:
   1395 //      - num       : Numerator
   1396 //      - den       : Denominator
   1397 //
   1398 // Return value     : Result of the division (as a int32_t), i.e., the
   1399 //                    integer part of num/den.
   1400 //
   1401 
   1402 //
   1403 // WebRtcSpl_DivW32W16ResW16(...)
   1404 //
   1405 // Divides a int32_t |num| by a int16_t |den|, assuming that the
   1406 // result is less than 32768, otherwise an unpredictable result will occur.
   1407 //
   1408 // If |den|==0, (int16_t)0x7FFF is returned.
   1409 //
   1410 // Input:
   1411 //      - num       : Numerator
   1412 //      - den       : Denominator
   1413 //
   1414 // Return value     : Result of the division (as a int16_t), i.e., the
   1415 //                    integer part of num/den.
   1416 //
   1417 
   1418 //
   1419 // WebRtcSpl_DivResultInQ31(...)
   1420 //
   1421 // Divides a int32_t |num| by a int16_t |den|, assuming that the
   1422 // absolute value of the denominator is larger than the numerator, otherwise
   1423 // an unpredictable result will occur.
   1424 //
   1425 // Input:
   1426 //      - num       : Numerator
   1427 //      - den       : Denominator
   1428 //
   1429 // Return value     : Result of the division in Q31.
   1430 //
   1431 
   1432 //
   1433 // WebRtcSpl_DivW32HiLow(...)
   1434 //
   1435 // Divides a int32_t |num| by a denominator in hi, low format. The
   1436 // absolute value of the denominator has to be larger (or equal to) the
   1437 // numerator.
   1438 //
   1439 // Input:
   1440 //      - num       : Numerator
   1441 //      - den_hi    : High part of denominator
   1442 //      - den_low   : Low part of denominator
   1443 //
   1444 // Return value     : Divided value in Q31
   1445 //
   1446 
   1447 //
   1448 // WebRtcSpl_Energy(...)
   1449 //
   1450 // Calculates the energy of a vector
   1451 //
   1452 // Input:
   1453 //      - vector        : Vector which the energy should be calculated on
   1454 //      - vector_length : Number of samples in vector
   1455 //
   1456 // Output:
   1457 //      - scale_factor  : Number of left bit shifts needed to get the physical
   1458 //                        energy value, i.e, to get the Q0 value
   1459 //
   1460 // Return value         : Energy value in Q(-|scale_factor|)
   1461 //
   1462 
   1463 //
   1464 // WebRtcSpl_FilterAR(...)
   1465 //
   1466 // Performs a 32-bit AR filtering on a vector in Q12
   1467 //
   1468 // Input:
   1469 //  - ar_coef                   : AR-coefficient vector (values in Q12),
   1470 //                                ar_coef[0] must be 4096.
   1471 //  - ar_coef_length            : Number of coefficients in |ar_coef|.
   1472 //  - in_vector                 : Vector to be filtered.
   1473 //  - in_vector_length          : Number of samples in |in_vector|.
   1474 //  - filter_state              : Current state (higher part) of the filter.
   1475 //  - filter_state_length       : Length (in samples) of |filter_state|.
   1476 //  - filter_state_low          : Current state (lower part) of the filter.
   1477 //  - filter_state_low_length   : Length (in samples) of |filter_state_low|.
   1478 //  - out_vector_low_length     : Maximum length (in samples) of
   1479 //                                |out_vector_low|.
   1480 //
   1481 // Output:
   1482 //  - filter_state              : Updated state (upper part) vector.
   1483 //  - filter_state_low          : Updated state (lower part) vector.
   1484 //  - out_vector                : Vector containing the upper part of the
   1485 //                                filtered values.
   1486 //  - out_vector_low            : Vector containing the lower part of the
   1487 //                                filtered values.
   1488 //
   1489 // Return value                 : Number of samples in the |out_vector|.
   1490 //
   1491 
   1492 //
   1493 // WebRtcSpl_ComplexIFFT(...)
   1494 //
   1495 // Complex Inverse FFT
   1496 //
   1497 // Computes an inverse complex 2^|stages|-point FFT on the input vector, which
   1498 // is in bit-reversed order. The original content of the vector is destroyed in
   1499 // the process, since the input is overwritten by the output, normal-ordered,
   1500 // FFT vector. With X as the input complex vector, y as the output complex
   1501 // vector and with M = 2^|stages|, the following is computed:
   1502 //
   1503 //        M-1
   1504 // y(k) = sum[X(i)*[cos(2*pi*i*k/M) + j*sin(2*pi*i*k/M)]]
   1505 //        i=0
   1506 //
   1507 // The implementations are optimized for speed, not for code size. It uses the
   1508 // decimation-in-time algorithm with radix-2 butterfly technique.
   1509 //
   1510 // Input:
   1511 //      - vector    : In pointer to complex vector containing 2^|stages|
   1512 //                    real elements interleaved with 2^|stages| imaginary
   1513 //                    elements.
   1514 //                    [ReImReImReIm....]
   1515 //                    The elements are in Q(-scale) domain, see more on Return
   1516 //                    Value below.
   1517 //
   1518 //      - stages    : Number of FFT stages. Must be at least 3 and at most 10,
   1519 //                    since the table WebRtcSpl_kSinTable1024[] is 1024
   1520 //                    elements long.
   1521 //
   1522 //      - mode      : This parameter gives the user to choose how the FFT
   1523 //                    should work.
   1524 //                    mode==0: Low-complexity and Low-accuracy mode
   1525 //                    mode==1: High-complexity and High-accuracy mode
   1526 //
   1527 // Output:
   1528 //      - vector    : Out pointer to the FFT vector (the same as input).
   1529 //
   1530 // Return Value     : The scale value that tells the number of left bit shifts
   1531 //                    that the elements in the |vector| should be shifted with
   1532 //                    in order to get Q0 values, i.e. the physically correct
   1533 //                    values. The scale parameter is always 0 or positive,
   1534 //                    except if N>1024 (|stages|>10), which returns a scale
   1535 //                    value of -1, indicating error.
   1536 //
   1537 
   1538 //
   1539 // WebRtcSpl_ComplexFFT(...)
   1540 //
   1541 // Complex FFT
   1542 //
   1543 // Computes a complex 2^|stages|-point FFT on the input vector, which is in
   1544 // bit-reversed order. The original content of the vector is destroyed in
   1545 // the process, since the input is overwritten by the output, normal-ordered,
   1546 // FFT vector. With x as the input complex vector, Y as the output complex
   1547 // vector and with M = 2^|stages|, the following is computed:
   1548 //
   1549 //              M-1
   1550 // Y(k) = 1/M * sum[x(i)*[cos(2*pi*i*k/M) + j*sin(2*pi*i*k/M)]]
   1551 //              i=0
   1552 //
   1553 // The implementations are optimized for speed, not for code size. It uses the
   1554 // decimation-in-time algorithm with radix-2 butterfly technique.
   1555 //
   1556 // This routine prevents overflow by scaling by 2 before each FFT stage. This is
   1557 // a fixed scaling, for proper normalization - there will be log2(n) passes, so
   1558 // this results in an overall factor of 1/n, distributed to maximize arithmetic
   1559 // accuracy.
   1560 //
   1561 // Input:
   1562 //      - vector    : In pointer to complex vector containing 2^|stages| real
   1563 //                    elements interleaved with 2^|stages| imaginary elements.
   1564 //                    [ReImReImReIm....]
   1565 //                    The output is in the Q0 domain.
   1566 //
   1567 //      - stages    : Number of FFT stages. Must be at least 3 and at most 10,
   1568 //                    since the table WebRtcSpl_kSinTable1024[] is 1024
   1569 //                    elements long.
   1570 //
   1571 //      - mode      : This parameter gives the user to choose how the FFT
   1572 //                    should work.
   1573 //                    mode==0: Low-complexity and Low-accuracy mode
   1574 //                    mode==1: High-complexity and High-accuracy mode
   1575 //
   1576 // Output:
   1577 //      - vector    : The output FFT vector is in the Q0 domain.
   1578 //
   1579 // Return value     : The scale parameter is always 0, except if N>1024,
   1580 //                    which returns a scale value of -1, indicating error.
   1581 //
   1582 
   1583 //
   1584 // WebRtcSpl_AnalysisQMF(...)
   1585 //
   1586 // Splits a 0-2*F Hz signal into two sub bands: 0-F Hz and F-2*F Hz. The
   1587 // current version has F = 8000, therefore, a super-wideband audio signal is
   1588 // split to lower-band 0-8 kHz and upper-band 8-16 kHz.
   1589 //
   1590 // Input:
   1591 //      - in_data       : Wide band speech signal, 320 samples (10 ms)
   1592 //
   1593 // Input & Output:
   1594 //      - filter_state1 : Filter state for first All-pass filter
   1595 //      - filter_state2 : Filter state for second All-pass filter
   1596 //
   1597 // Output:
   1598 //      - low_band      : Lower-band signal 0-8 kHz band, 160 samples (10 ms)
   1599 //      - high_band     : Upper-band signal 8-16 kHz band (flipped in frequency
   1600 //                        domain), 160 samples (10 ms)
   1601 //
   1602 
   1603 //
   1604 // WebRtcSpl_SynthesisQMF(...)
   1605 //
   1606 // Combines the two sub bands (0-F and F-2*F Hz) into a signal of 0-2*F
   1607 // Hz, (current version has F = 8000 Hz). So the filter combines lower-band
   1608 // (0-8 kHz) and upper-band (8-16 kHz) channels to obtain super-wideband 0-16
   1609 // kHz audio.
   1610 //
   1611 // Input:
   1612 //      - low_band      : The signal with the 0-8 kHz band, 160 samples (10 ms)
   1613 //      - high_band     : The signal with the 8-16 kHz band, 160 samples (10 ms)
   1614 //
   1615 // Input & Output:
   1616 //      - filter_state1 : Filter state for first All-pass filter
   1617 //      - filter_state2 : Filter state for second All-pass filter
   1618 //
   1619 // Output:
   1620 //      - out_data      : Super-wideband speech signal, 0-16 kHz
   1621 //
   1622 
   1623 // int16_t WebRtcSpl_SatW32ToW16(...)
   1624 //
   1625 // This function saturates a 32-bit word into a 16-bit word.
   1626 //
   1627 // Input:
   1628 //      - value32   : The value of a 32-bit word.
   1629 //
   1630 // Output:
   1631 //      - out16     : the saturated 16-bit word.
   1632 //
   1633 
   1634 // int32_t WebRtc_MulAccumW16(...)
   1635 //
   1636 // This function multiply a 16-bit word by a 16-bit word, and accumulate this
   1637 // value to a 32-bit integer.
   1638 //
   1639 // Input:
   1640 //      - a    : The value of the first 16-bit word.
   1641 //      - b    : The value of the second 16-bit word.
   1642 //      - c    : The value of an 32-bit integer.
   1643 //
   1644 // Return Value: The value of a * b + c.
   1645 //
   1646