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gfiber / vendor / opensource / webrtc / d73f3b5ff617e5b395e2af72e29289b87a1873e9 / . / trunk / src / common_audio / signal_processing / include / signal_processing_library.h
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/*
* Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
/*
* This header file includes all of the fix point signal processing library (SPL) function
* descriptions and declarations.
* For specific function calls, see bottom of file.
*/
#ifndef WEBRTC_SPL_SIGNAL_PROCESSING_LIBRARY_H_
#define WEBRTC_SPL_SIGNAL_PROCESSING_LIBRARY_H_
#include <string.h>
#include "typedefs.h"
#ifdef ARM_WINM
#include <Armintr.h> // intrinsic file for windows mobile
#endif
// Macros specific for the fixed point implementation
#define WEBRTC_SPL_WORD16_MAX 32767
#define WEBRTC_SPL_WORD16_MIN -32768
#define WEBRTC_SPL_WORD32_MAX (WebRtc_Word32)0x7fffffff
#define WEBRTC_SPL_WORD32_MIN (WebRtc_Word32)0x80000000
#define WEBRTC_SPL_MAX_LPC_ORDER 14
#define WEBRTC_SPL_MAX_SEED_USED 0x80000000L
#define WEBRTC_SPL_MIN(A, B) (A < B ? A : B) // Get min value
#define WEBRTC_SPL_MAX(A, B) (A > B ? A : B) // Get max value
#define WEBRTC_SPL_ABS_W16(a) \
(((WebRtc_Word16)a >= 0) ? ((WebRtc_Word16)a) : -((WebRtc_Word16)a))
#define WEBRTC_SPL_ABS_W32(a) \
(((WebRtc_Word32)a >= 0) ? ((WebRtc_Word32)a) : -((WebRtc_Word32)a))
#if (defined WEBRTC_TARGET_PC)||(defined __TARGET_XSCALE)
#define WEBRTC_SPL_GET_BYTE(a, nr) (((WebRtc_Word8 *)a)[nr])
#define WEBRTC_SPL_SET_BYTE(d_ptr, val, index) \
(((WebRtc_Word8 *)d_ptr)[index] = (val))
#elif defined WEBRTC_BIG_ENDIAN
#define WEBRTC_SPL_GET_BYTE(a, nr) \
((((WebRtc_Word16 *)a)[nr >> 1]) >> (((nr + 1) & 0x1) * 8) & 0x00ff)
#define WEBRTC_SPL_SET_BYTE(d_ptr, val, index) \
((WebRtc_Word16 *)d_ptr)[index >> 1] = \
((((WebRtc_Word16 *)d_ptr)[index >> 1]) \
& (0x00ff << (8 * ((index) & 0x1)))) | (val << (8 * ((index + 1) & 0x1)))
#else
#define WEBRTC_SPL_GET_BYTE(a,nr) \
((((WebRtc_Word16 *)(a))[(nr) >> 1]) >> (((nr) & 0x1) * 8) & 0x00ff)
#define WEBRTC_SPL_SET_BYTE(d_ptr, val, index) \
((WebRtc_Word16 *)(d_ptr))[(index) >> 1] = \
((((WebRtc_Word16 *)(d_ptr))[(index) >> 1]) \
& (0x00ff << (8 * (((index) + 1) & 0x1)))) | \
((val) << (8 * ((index) & 0x1)))
#endif
#define WEBRTC_SPL_MUL(a, b) \
((WebRtc_Word32) ((WebRtc_Word32)(a) * (WebRtc_Word32)(b)))
#define WEBRTC_SPL_UMUL(a, b) \
((WebRtc_UWord32) ((WebRtc_UWord32)(a) * (WebRtc_UWord32)(b)))
#define WEBRTC_SPL_UMUL_RSFT16(a, b) \
((WebRtc_UWord32) ((WebRtc_UWord32)(a) * (WebRtc_UWord32)(b)) >> 16)
#define WEBRTC_SPL_UMUL_16_16(a, b) \
((WebRtc_UWord32) (WebRtc_UWord16)(a) * (WebRtc_UWord16)(b))
#define WEBRTC_SPL_UMUL_16_16_RSFT16(a, b) \
(((WebRtc_UWord32) (WebRtc_UWord16)(a) * (WebRtc_UWord16)(b)) >> 16)
#define WEBRTC_SPL_UMUL_32_16(a, b) \
((WebRtc_UWord32) ((WebRtc_UWord32)(a) * (WebRtc_UWord16)(b)))
#define WEBRTC_SPL_UMUL_32_16_RSFT16(a, b) \
((WebRtc_UWord32) ((WebRtc_UWord32)(a) * (WebRtc_UWord16)(b)) >> 16)
#define WEBRTC_SPL_MUL_16_U16(a, b) \
((WebRtc_Word32)(WebRtc_Word16)(a) * (WebRtc_UWord16)(b))
#define WEBRTC_SPL_DIV(a, b) \
((WebRtc_Word32) ((WebRtc_Word32)(a) / (WebRtc_Word32)(b)))
#define WEBRTC_SPL_UDIV(a, b) \
((WebRtc_UWord32) ((WebRtc_UWord32)(a) / (WebRtc_UWord32)(b)))
#ifndef WEBRTC_ARCH_ARM_V7A
// For ARMv7 platforms, these are inline functions in spl_inl_armv7.h
#define WEBRTC_SPL_MUL_16_16(a, b) \
((WebRtc_Word32) (((WebRtc_Word16)(a)) * ((WebRtc_Word16)(b))))
#define WEBRTC_SPL_MUL_16_32_RSFT16(a, b) \
(WEBRTC_SPL_MUL_16_16(a, b >> 16) \
+ ((WEBRTC_SPL_MUL_16_16(a, (b & 0xffff) >> 1) + 0x4000) >> 15))
#define WEBRTC_SPL_MUL_32_32_RSFT32(a32a, a32b, b32) \
((WebRtc_Word32)(WEBRTC_SPL_MUL_16_32_RSFT16(a32a, b32) \
+ (WEBRTC_SPL_MUL_16_32_RSFT16(a32b, b32) >> 16)))
#define WEBRTC_SPL_MUL_32_32_RSFT32BI(a32, b32) \
((WebRtc_Word32)(WEBRTC_SPL_MUL_16_32_RSFT16(( \
(WebRtc_Word16)(a32 >> 16)), b32) + \
(WEBRTC_SPL_MUL_16_32_RSFT16(( \
(WebRtc_Word16)((a32 & 0x0000FFFF) >> 1)), b32) >> 15)))
#endif
#define WEBRTC_SPL_MUL_16_32_RSFT11(a, b) \
((WEBRTC_SPL_MUL_16_16(a, (b) >> 16) << 5) \
+ (((WEBRTC_SPL_MUL_16_U16(a, (WebRtc_UWord16)(b)) >> 1) + 0x0200) >> 10))
#define WEBRTC_SPL_MUL_16_32_RSFT14(a, b) \
((WEBRTC_SPL_MUL_16_16(a, (b) >> 16) << 2) \
+ (((WEBRTC_SPL_MUL_16_U16(a, (WebRtc_UWord16)(b)) >> 1) + 0x1000) >> 13))
#define WEBRTC_SPL_MUL_16_32_RSFT15(a, b) \
((WEBRTC_SPL_MUL_16_16(a, (b) >> 16) << 1) \
+ (((WEBRTC_SPL_MUL_16_U16(a, (WebRtc_UWord16)(b)) >> 1) + 0x2000) >> 14))
#ifdef ARM_WINM
#define WEBRTC_SPL_MUL_16_16(a, b) \
_SmulLo_SW_SL((WebRtc_Word16)(a), (WebRtc_Word16)(b))
#endif
#define WEBRTC_SPL_MUL_16_16_RSFT(a, b, c) \
(WEBRTC_SPL_MUL_16_16(a, b) >> (c))
#define WEBRTC_SPL_MUL_16_16_RSFT_WITH_ROUND(a, b, c) \
((WEBRTC_SPL_MUL_16_16(a, b) + ((WebRtc_Word32) \
(((WebRtc_Word32)1) << ((c) - 1)))) >> (c))
#define WEBRTC_SPL_MUL_16_16_RSFT_WITH_FIXROUND(a, b) \
((WEBRTC_SPL_MUL_16_16(a, b) + ((WebRtc_Word32) (1 << 14))) >> 15)
// C + the 32 most significant bits of A * B
#define WEBRTC_SPL_SCALEDIFF32(A, B, C) \
(C + (B >> 16) * A + (((WebRtc_UWord32)(0x0000FFFF & B) * A) >> 16))
#define WEBRTC_SPL_ADD_SAT_W32(a, b) WebRtcSpl_AddSatW32(a, b)
#define WEBRTC_SPL_SAT(a, b, c) (b > a ? a : b < c ? c : b)
#define WEBRTC_SPL_MUL_32_16(a, b) ((a) * (b))
#define WEBRTC_SPL_SUB_SAT_W32(a, b) WebRtcSpl_SubSatW32(a, b)
#define WEBRTC_SPL_ADD_SAT_W16(a, b) WebRtcSpl_AddSatW16(a, b)
#define WEBRTC_SPL_SUB_SAT_W16(a, b) WebRtcSpl_SubSatW16(a, b)
// We cannot do casting here due to signed/unsigned problem
#define WEBRTC_SPL_IS_NEG(a) ((a) & 0x80000000)
// Shifting with negative numbers allowed
// Positive means left shift
#define WEBRTC_SPL_SHIFT_W16(x, c) \
(((c) >= 0) ? ((x) << (c)) : ((x) >> (-(c))))
#define WEBRTC_SPL_SHIFT_W32(x, c) \
(((c) >= 0) ? ((x) << (c)) : ((x) >> (-(c))))
// Shifting with negative numbers not allowed
// We cannot do casting here due to signed/unsigned problem
#define WEBRTC_SPL_RSHIFT_W16(x, c) ((x) >> (c))
#define WEBRTC_SPL_LSHIFT_W16(x, c) ((x) << (c))
#define WEBRTC_SPL_RSHIFT_W32(x, c) ((x) >> (c))
#define WEBRTC_SPL_LSHIFT_W32(x, c) ((x) << (c))
#define WEBRTC_SPL_RSHIFT_U16(x, c) ((WebRtc_UWord16)(x) >> (c))
#define WEBRTC_SPL_LSHIFT_U16(x, c) ((WebRtc_UWord16)(x) << (c))
#define WEBRTC_SPL_RSHIFT_U32(x, c) ((WebRtc_UWord32)(x) >> (c))
#define WEBRTC_SPL_LSHIFT_U32(x, c) ((WebRtc_UWord32)(x) << (c))
#define WEBRTC_SPL_VNEW(t, n) (t *) malloc (sizeof (t) * (n))
#define WEBRTC_SPL_FREE free
#define WEBRTC_SPL_RAND(a) \
((WebRtc_Word16)(WEBRTC_SPL_MUL_16_16_RSFT((a), 18816, 7) & 0x00007fff))
#ifdef __cplusplus
extern "C"
{
#endif
#define WEBRTC_SPL_MEMCPY_W8(v1, v2, length) \
memcpy(v1, v2, (length) * sizeof(char))
#define WEBRTC_SPL_MEMCPY_W16(v1, v2, length) \
memcpy(v1, v2, (length) * sizeof(WebRtc_Word16))
#define WEBRTC_SPL_MEMMOVE_W16(v1, v2, length) \
memmove(v1, v2, (length) * sizeof(WebRtc_Word16))
// inline functions:
#include "spl_inl.h"
// Get SPL Version
WebRtc_Word16 WebRtcSpl_get_version(char* version,
WebRtc_Word16 length_in_bytes);
int WebRtcSpl_GetScalingSquare(WebRtc_Word16* in_vector,
int in_vector_length,
int times);
// Copy and set operations. Implementation in copy_set_operations.c.
// Descriptions at bottom of file.
void WebRtcSpl_MemSetW16(WebRtc_Word16* vector,
WebRtc_Word16 set_value,
int vector_length);
void WebRtcSpl_MemSetW32(WebRtc_Word32* vector,
WebRtc_Word32 set_value,
int vector_length);
void WebRtcSpl_MemCpyReversedOrder(WebRtc_Word16* out_vector,
WebRtc_Word16* in_vector,
int vector_length);
WebRtc_Word16 WebRtcSpl_CopyFromEndW16(G_CONST WebRtc_Word16* in_vector,
WebRtc_Word16 in_vector_length,
WebRtc_Word16 samples,
WebRtc_Word16* out_vector);
WebRtc_Word16 WebRtcSpl_ZerosArrayW16(WebRtc_Word16* vector,
WebRtc_Word16 vector_length);
WebRtc_Word16 WebRtcSpl_ZerosArrayW32(WebRtc_Word32* vector,
WebRtc_Word16 vector_length);
WebRtc_Word16 WebRtcSpl_OnesArrayW16(WebRtc_Word16* vector,
WebRtc_Word16 vector_length);
WebRtc_Word16 WebRtcSpl_OnesArrayW32(WebRtc_Word32* vector,
WebRtc_Word16 vector_length);
// End: Copy and set operations.
// Minimum and maximum operations. Implementation in min_max_operations.c.
// Descriptions at bottom of file.
WebRtc_Word16 WebRtcSpl_MaxAbsValueW16(const WebRtc_Word16* vector,
WebRtc_Word16 length);
WebRtc_Word32 WebRtcSpl_MaxAbsValueW32(G_CONST WebRtc_Word32* vector,
WebRtc_Word16 length);
WebRtc_Word16 WebRtcSpl_MinValueW16(G_CONST WebRtc_Word16* vector,
WebRtc_Word16 length);
WebRtc_Word32 WebRtcSpl_MinValueW32(G_CONST WebRtc_Word32* vector,
WebRtc_Word16 length);
WebRtc_Word16 WebRtcSpl_MaxValueW16(G_CONST WebRtc_Word16* vector,
WebRtc_Word16 length);
WebRtc_Word16 WebRtcSpl_MaxAbsIndexW16(G_CONST WebRtc_Word16* vector,
WebRtc_Word16 length);
WebRtc_Word32 WebRtcSpl_MaxValueW32(G_CONST WebRtc_Word32* vector,
WebRtc_Word16 length);
WebRtc_Word16 WebRtcSpl_MinIndexW16(G_CONST WebRtc_Word16* vector,
WebRtc_Word16 length);
WebRtc_Word16 WebRtcSpl_MinIndexW32(G_CONST WebRtc_Word32* vector,
WebRtc_Word16 length);
WebRtc_Word16 WebRtcSpl_MaxIndexW16(G_CONST WebRtc_Word16* vector,
WebRtc_Word16 length);
WebRtc_Word16 WebRtcSpl_MaxIndexW32(G_CONST WebRtc_Word32* vector,
WebRtc_Word16 length);
// End: Minimum and maximum operations.
// Vector scaling operations. Implementation in vector_scaling_operations.c.
// Description at bottom of file.
void WebRtcSpl_VectorBitShiftW16(WebRtc_Word16* out_vector,
WebRtc_Word16 vector_length,
G_CONST WebRtc_Word16* in_vector,
WebRtc_Word16 right_shifts);
void WebRtcSpl_VectorBitShiftW32(WebRtc_Word32* out_vector,
WebRtc_Word16 vector_length,
G_CONST WebRtc_Word32* in_vector,
WebRtc_Word16 right_shifts);
void WebRtcSpl_VectorBitShiftW32ToW16(WebRtc_Word16* out_vector,
WebRtc_Word16 vector_length,
G_CONST WebRtc_Word32* in_vector,
WebRtc_Word16 right_shifts);
void WebRtcSpl_ScaleVector(G_CONST WebRtc_Word16* in_vector,
WebRtc_Word16* out_vector,
WebRtc_Word16 gain,
WebRtc_Word16 vector_length,
WebRtc_Word16 right_shifts);
void WebRtcSpl_ScaleVectorWithSat(G_CONST WebRtc_Word16* in_vector,
WebRtc_Word16* out_vector,
WebRtc_Word16 gain,
WebRtc_Word16 vector_length,
WebRtc_Word16 right_shifts);
void WebRtcSpl_ScaleAndAddVectors(G_CONST WebRtc_Word16* in_vector1,
WebRtc_Word16 gain1, int right_shifts1,
G_CONST WebRtc_Word16* in_vector2,
WebRtc_Word16 gain2, int right_shifts2,
WebRtc_Word16* out_vector,
int vector_length);
// End: Vector scaling operations.
// iLBC specific functions. Implementations in ilbc_specific_functions.c.
// Description at bottom of file.
void WebRtcSpl_ScaleAndAddVectorsWithRound(WebRtc_Word16* in_vector1,
WebRtc_Word16 scale1,
WebRtc_Word16* in_vector2,
WebRtc_Word16 scale2,
WebRtc_Word16 right_shifts,
WebRtc_Word16* out_vector,
WebRtc_Word16 vector_length);
void WebRtcSpl_ReverseOrderMultArrayElements(WebRtc_Word16* out_vector,
G_CONST WebRtc_Word16* in_vector,
G_CONST WebRtc_Word16* window,
WebRtc_Word16 vector_length,
WebRtc_Word16 right_shifts);
void WebRtcSpl_ElementwiseVectorMult(WebRtc_Word16* out_vector,
G_CONST WebRtc_Word16* in_vector,
G_CONST WebRtc_Word16* window,
WebRtc_Word16 vector_length,
WebRtc_Word16 right_shifts);
void WebRtcSpl_AddVectorsAndShift(WebRtc_Word16* out_vector,
G_CONST WebRtc_Word16* in_vector1,
G_CONST WebRtc_Word16* in_vector2,
WebRtc_Word16 vector_length,
WebRtc_Word16 right_shifts);
void WebRtcSpl_AddAffineVectorToVector(WebRtc_Word16* out_vector,
WebRtc_Word16* in_vector,
WebRtc_Word16 gain,
WebRtc_Word32 add_constant,
WebRtc_Word16 right_shifts,
int vector_length);
void WebRtcSpl_AffineTransformVector(WebRtc_Word16* out_vector,
WebRtc_Word16* in_vector,
WebRtc_Word16 gain,
WebRtc_Word32 add_constant,
WebRtc_Word16 right_shifts,
int vector_length);
// End: iLBC specific functions.
// Signal processing operations. Descriptions at bottom of this file.
int WebRtcSpl_AutoCorrelation(G_CONST WebRtc_Word16* vector,
int vector_length, int order,
WebRtc_Word32* result_vector,
int* scale);
WebRtc_Word16 WebRtcSpl_LevinsonDurbin(WebRtc_Word32* auto_corr,
WebRtc_Word16* lpc_coef,
WebRtc_Word16* refl_coef,
WebRtc_Word16 order);
void WebRtcSpl_ReflCoefToLpc(G_CONST WebRtc_Word16* refl_coef,
int use_order,
WebRtc_Word16* lpc_coef);
void WebRtcSpl_LpcToReflCoef(WebRtc_Word16* lpc_coef,
int use_order,
WebRtc_Word16* refl_coef);
void WebRtcSpl_AutoCorrToReflCoef(G_CONST WebRtc_Word32* auto_corr,
int use_order,
WebRtc_Word16* refl_coef);
void WebRtcSpl_CrossCorrelation(WebRtc_Word32* cross_corr,
WebRtc_Word16* vector1,
WebRtc_Word16* vector2,
WebRtc_Word16 dim_vector,
WebRtc_Word16 dim_cross_corr,
WebRtc_Word16 right_shifts,
WebRtc_Word16 step_vector2);
void WebRtcSpl_GetHanningWindow(WebRtc_Word16* window, WebRtc_Word16 size);
void WebRtcSpl_SqrtOfOneMinusXSquared(WebRtc_Word16* in_vector,
int vector_length,
WebRtc_Word16* out_vector);
// End: Signal processing operations.
// Randomization functions. Implementations collected in randomization_functions.c and
// descriptions at bottom of this file.
WebRtc_UWord32 WebRtcSpl_IncreaseSeed(WebRtc_UWord32* seed);
WebRtc_Word16 WebRtcSpl_RandU(WebRtc_UWord32* seed);
WebRtc_Word16 WebRtcSpl_RandN(WebRtc_UWord32* seed);
WebRtc_Word16 WebRtcSpl_RandUArray(WebRtc_Word16* vector,
WebRtc_Word16 vector_length,
WebRtc_UWord32* seed);
// End: Randomization functions.
// Math functions
WebRtc_Word32 WebRtcSpl_Sqrt(WebRtc_Word32 value);
WebRtc_Word32 WebRtcSpl_SqrtFloor(WebRtc_Word32 value);
// Divisions. Implementations collected in division_operations.c and
// descriptions at bottom of this file.
WebRtc_UWord32 WebRtcSpl_DivU32U16(WebRtc_UWord32 num, WebRtc_UWord16 den);
WebRtc_Word32 WebRtcSpl_DivW32W16(WebRtc_Word32 num, WebRtc_Word16 den);
WebRtc_Word16 WebRtcSpl_DivW32W16ResW16(WebRtc_Word32 num, WebRtc_Word16 den);
WebRtc_Word32 WebRtcSpl_DivResultInQ31(WebRtc_Word32 num, WebRtc_Word32 den);
WebRtc_Word32 WebRtcSpl_DivW32HiLow(WebRtc_Word32 num, WebRtc_Word16 den_hi,
WebRtc_Word16 den_low);
// End: Divisions.
WebRtc_Word32 WebRtcSpl_Energy(WebRtc_Word16* vector,
int vector_length,
int* scale_factor);
WebRtc_Word32 WebRtcSpl_DotProductWithScale(WebRtc_Word16* vector1,
WebRtc_Word16* vector2,
int vector_length,
int scaling);
// Filter operations.
int WebRtcSpl_FilterAR(G_CONST WebRtc_Word16* ar_coef, int ar_coef_length,
G_CONST WebRtc_Word16* in_vector, int in_vector_length,
WebRtc_Word16* filter_state, int filter_state_length,
WebRtc_Word16* filter_state_low,
int filter_state_low_length, WebRtc_Word16* out_vector,
WebRtc_Word16* out_vector_low, int out_vector_low_length);
void WebRtcSpl_FilterMAFastQ12(WebRtc_Word16* in_vector,
WebRtc_Word16* out_vector,
WebRtc_Word16* ma_coef,
WebRtc_Word16 ma_coef_length,
WebRtc_Word16 vector_length);
// Performs a AR filtering on a vector in Q12
// Input:
// - data_in : Input samples
// - data_out : State information in positions
// data_out[-order] .. data_out[-1]
// - coefficients : Filter coefficients (in Q12)
// - coefficients_length: Number of coefficients (order+1)
// - data_length : Number of samples to be filtered
// Output:
// - data_out : Filtered samples
void WebRtcSpl_FilterARFastQ12(const int16_t* data_in,
int16_t* data_out,
const int16_t* __restrict coefficients,
int coefficients_length,
int data_length);
// Performs a MA down sampling filter on a vector
// Input:
// - data_in : Input samples (state in positions
// data_in[-order] .. data_in[-1])
// - data_in_length : Number of samples in |data_in| to be filtered.
// This must be at least
// |delay| + |factor|*(|out_vector_length|-1) + 1)
// - data_out_length : Number of down sampled samples desired
// - coefficients : Filter coefficients (in Q12)
// - coefficients_length: Number of coefficients (order+1)
// - factor : Decimation factor
// - delay : Delay of filter (compensated for in out_vector)
// Output:
// - data_out : Filtered samples
// Return value : 0 if OK, -1 if |in_vector| is too short
int WebRtcSpl_DownsampleFast(const int16_t* data_in,
int data_in_length,
int16_t* data_out,
int data_out_length,
const int16_t* __restrict coefficients,
int coefficients_length,
int factor,
int delay);
// End: Filter operations.
// FFT operations
int WebRtcSpl_ComplexFFT(WebRtc_Word16 vector[], int stages, int mode);
int WebRtcSpl_ComplexIFFT(WebRtc_Word16 vector[], int stages, int mode);
// Treat a 16-bit complex data buffer |complex_data| as an array of 32-bit
// values, and swap elements whose indexes are bit-reverses of each other.
//
// Input:
// - complex_data : Complex data buffer containing 2^|stages| real
// elements interleaved with 2^|stages| imaginary
// elements: [Re Im Re Im Re Im....]
// - stages : Number of FFT stages. Must be at least 3 and at most
// 10, since the table WebRtcSpl_kSinTable1024[] is 1024
// elements long.
//
// Output:
// - complex_data : The complex data buffer.
void WebRtcSpl_ComplexBitReverse(int16_t* __restrict complex_data, int stages);
// End: FFT operations
/************************************************************
*
* RESAMPLING FUNCTIONS AND THEIR STRUCTS ARE DEFINED BELOW
*
************************************************************/
/*******************************************************************
* resample.c
*
* Includes the following resampling combinations
* 22 kHz -> 16 kHz
* 16 kHz -> 22 kHz
* 22 kHz -> 8 kHz
* 8 kHz -> 22 kHz
*
******************************************************************/
// state structure for 22 -> 16 resampler
typedef struct
{
WebRtc_Word32 S_22_44[8];
WebRtc_Word32 S_44_32[8];
WebRtc_Word32 S_32_16[8];
} WebRtcSpl_State22khzTo16khz;
void WebRtcSpl_Resample22khzTo16khz(const WebRtc_Word16* in,
WebRtc_Word16* out,
WebRtcSpl_State22khzTo16khz* state,
WebRtc_Word32* tmpmem);
void WebRtcSpl_ResetResample22khzTo16khz(WebRtcSpl_State22khzTo16khz* state);
// state structure for 16 -> 22 resampler
typedef struct
{
WebRtc_Word32 S_16_32[8];
WebRtc_Word32 S_32_22[8];
} WebRtcSpl_State16khzTo22khz;
void WebRtcSpl_Resample16khzTo22khz(const WebRtc_Word16* in,
WebRtc_Word16* out,
WebRtcSpl_State16khzTo22khz* state,
WebRtc_Word32* tmpmem);
void WebRtcSpl_ResetResample16khzTo22khz(WebRtcSpl_State16khzTo22khz* state);
// state structure for 22 -> 8 resampler
typedef struct
{
WebRtc_Word32 S_22_22[16];
WebRtc_Word32 S_22_16[8];
WebRtc_Word32 S_16_8[8];
} WebRtcSpl_State22khzTo8khz;
void WebRtcSpl_Resample22khzTo8khz(const WebRtc_Word16* in, WebRtc_Word16* out,
WebRtcSpl_State22khzTo8khz* state,
WebRtc_Word32* tmpmem);
void WebRtcSpl_ResetResample22khzTo8khz(WebRtcSpl_State22khzTo8khz* state);
// state structure for 8 -> 22 resampler
typedef struct
{
WebRtc_Word32 S_8_16[8];
WebRtc_Word32 S_16_11[8];
WebRtc_Word32 S_11_22[8];
} WebRtcSpl_State8khzTo22khz;
void WebRtcSpl_Resample8khzTo22khz(const WebRtc_Word16* in, WebRtc_Word16* out,
WebRtcSpl_State8khzTo22khz* state,
WebRtc_Word32* tmpmem);
void WebRtcSpl_ResetResample8khzTo22khz(WebRtcSpl_State8khzTo22khz* state);
/*******************************************************************
* resample_fractional.c
* Functions for internal use in the other resample functions
*
* Includes the following resampling combinations
* 48 kHz -> 32 kHz
* 32 kHz -> 24 kHz
* 44 kHz -> 32 kHz
*
******************************************************************/
void WebRtcSpl_Resample48khzTo32khz(const WebRtc_Word32* In, WebRtc_Word32* Out,
const WebRtc_Word32 K);
void WebRtcSpl_Resample32khzTo24khz(const WebRtc_Word32* In, WebRtc_Word32* Out,
const WebRtc_Word32 K);
void WebRtcSpl_Resample44khzTo32khz(const WebRtc_Word32* In, WebRtc_Word32* Out,
const WebRtc_Word32 K);
/*******************************************************************
* resample_48khz.c
*
* Includes the following resampling combinations
* 48 kHz -> 16 kHz
* 16 kHz -> 48 kHz
* 48 kHz -> 8 kHz
* 8 kHz -> 48 kHz
*
******************************************************************/
typedef struct
{
WebRtc_Word32 S_48_48[16];
WebRtc_Word32 S_48_32[8];
WebRtc_Word32 S_32_16[8];
} WebRtcSpl_State48khzTo16khz;
void WebRtcSpl_Resample48khzTo16khz(const WebRtc_Word16* in, WebRtc_Word16* out,
WebRtcSpl_State48khzTo16khz* state,
WebRtc_Word32* tmpmem);
void WebRtcSpl_ResetResample48khzTo16khz(WebRtcSpl_State48khzTo16khz* state);
typedef struct
{
WebRtc_Word32 S_16_32[8];
WebRtc_Word32 S_32_24[8];
WebRtc_Word32 S_24_48[8];
} WebRtcSpl_State16khzTo48khz;
void WebRtcSpl_Resample16khzTo48khz(const WebRtc_Word16* in, WebRtc_Word16* out,
WebRtcSpl_State16khzTo48khz* state,
WebRtc_Word32* tmpmem);
void WebRtcSpl_ResetResample16khzTo48khz(WebRtcSpl_State16khzTo48khz* state);
typedef struct
{
WebRtc_Word32 S_48_24[8];
WebRtc_Word32 S_24_24[16];
WebRtc_Word32 S_24_16[8];
WebRtc_Word32 S_16_8[8];
} WebRtcSpl_State48khzTo8khz;
void WebRtcSpl_Resample48khzTo8khz(const WebRtc_Word16* in, WebRtc_Word16* out,
WebRtcSpl_State48khzTo8khz* state,
WebRtc_Word32* tmpmem);
void WebRtcSpl_ResetResample48khzTo8khz(WebRtcSpl_State48khzTo8khz* state);
typedef struct
{
WebRtc_Word32 S_8_16[8];
WebRtc_Word32 S_16_12[8];
WebRtc_Word32 S_12_24[8];
WebRtc_Word32 S_24_48[8];
} WebRtcSpl_State8khzTo48khz;
void WebRtcSpl_Resample8khzTo48khz(const WebRtc_Word16* in, WebRtc_Word16* out,
WebRtcSpl_State8khzTo48khz* state,
WebRtc_Word32* tmpmem);
void WebRtcSpl_ResetResample8khzTo48khz(WebRtcSpl_State8khzTo48khz* state);
/*******************************************************************
* resample_by_2.c
*
* Includes down and up sampling by a factor of two.
*
******************************************************************/
void WebRtcSpl_DownsampleBy2(const WebRtc_Word16* in, const WebRtc_Word16 len,
WebRtc_Word16* out, WebRtc_Word32* filtState);
void WebRtcSpl_UpsampleBy2(const WebRtc_Word16* in, WebRtc_Word16 len, WebRtc_Word16* out,
WebRtc_Word32* filtState);
/************************************************************
* END OF RESAMPLING FUNCTIONS
************************************************************/
void WebRtcSpl_AnalysisQMF(const WebRtc_Word16* in_data,
WebRtc_Word16* low_band,
WebRtc_Word16* high_band,
WebRtc_Word32* filter_state1,
WebRtc_Word32* filter_state2);
void WebRtcSpl_SynthesisQMF(const WebRtc_Word16* low_band,
const WebRtc_Word16* high_band,
WebRtc_Word16* out_data,
WebRtc_Word32* filter_state1,
WebRtc_Word32* filter_state2);
#ifdef __cplusplus
}
#endif // __cplusplus
#endif // WEBRTC_SPL_SIGNAL_PROCESSING_LIBRARY_H_
//
// WebRtcSpl_AddSatW16(...)
// WebRtcSpl_AddSatW32(...)
//
// Returns the result of a saturated 16-bit, respectively 32-bit, addition of
// the numbers specified by the |var1| and |var2| parameters.
//
// Input:
// - var1 : Input variable 1
// - var2 : Input variable 2
//
// Return value : Added and saturated value
//
//
// WebRtcSpl_SubSatW16(...)
// WebRtcSpl_SubSatW32(...)
//
// Returns the result of a saturated 16-bit, respectively 32-bit, subtraction
// of the numbers specified by the |var1| and |var2| parameters.
//
// Input:
// - var1 : Input variable 1
// - var2 : Input variable 2
//
// Returned value : Subtracted and saturated value
//
//
// WebRtcSpl_GetSizeInBits(...)
//
// Returns the # of bits that are needed at the most to represent the number
// specified by the |value| parameter.
//
// Input:
// - value : Input value
//
// Return value : Number of bits needed to represent |value|
//
//
// WebRtcSpl_NormW32(...)
//
// Norm returns the # of left shifts required to 32-bit normalize the 32-bit
// signed number specified by the |value| parameter.
//
// Input:
// - value : Input value
//
// Return value : Number of bit shifts needed to 32-bit normalize |value|
//
//
// WebRtcSpl_NormW16(...)
//
// Norm returns the # of left shifts required to 16-bit normalize the 16-bit
// signed number specified by the |value| parameter.
//
// Input:
// - value : Input value
//
// Return value : Number of bit shifts needed to 32-bit normalize |value|
//
//
// WebRtcSpl_NormU32(...)
//
// Norm returns the # of left shifts required to 32-bit normalize the unsigned
// 32-bit number specified by the |value| parameter.
//
// Input:
// - value : Input value
//
// Return value : Number of bit shifts needed to 32-bit normalize |value|
//
//
// WebRtcSpl_GetScalingSquare(...)
//
// Returns the # of bits required to scale the samples specified in the
// |in_vector| parameter so that, if the squares of the samples are added the
// # of times specified by the |times| parameter, the 32-bit addition will not
// overflow (result in WebRtc_Word32).
//
// Input:
// - in_vector : Input vector to check scaling on
// - in_vector_length : Samples in |in_vector|
// - times : Number of additions to be performed
//
// Return value : Number of right bit shifts needed to avoid
// overflow in the addition calculation
//
//
// WebRtcSpl_MemSetW16(...)
//
// Sets all the values in the WebRtc_Word16 vector |vector| of length
// |vector_length| to the specified value |set_value|
//
// Input:
// - vector : Pointer to the WebRtc_Word16 vector
// - set_value : Value specified
// - vector_length : Length of vector
//
//
// WebRtcSpl_MemSetW32(...)
//
// Sets all the values in the WebRtc_Word32 vector |vector| of length
// |vector_length| to the specified value |set_value|
//
// Input:
// - vector : Pointer to the WebRtc_Word16 vector
// - set_value : Value specified
// - vector_length : Length of vector
//
//
// WebRtcSpl_MemCpyReversedOrder(...)
//
// Copies all the values from the source WebRtc_Word16 vector |in_vector| to a
// destination WebRtc_Word16 vector |out_vector|. It is done in reversed order,
// meaning that the first sample of |in_vector| is copied to the last sample of
// the |out_vector|. The procedure continues until the last sample of
// |in_vector| has been copied to the first sample of |out_vector|. This
// creates a reversed vector. Used in e.g. prediction in iLBC.
//
// Input:
// - in_vector : Pointer to the first sample in a WebRtc_Word16 vector
// of length |length|
// - vector_length : Number of elements to copy
//
// Output:
// - out_vector : Pointer to the last sample in a WebRtc_Word16 vector
// of length |length|
//
//
// WebRtcSpl_CopyFromEndW16(...)
//
// Copies the rightmost |samples| of |in_vector| (of length |in_vector_length|)
// to the vector |out_vector|.
//
// Input:
// - in_vector : Input vector
// - in_vector_length : Number of samples in |in_vector|
// - samples : Number of samples to extract (from right side)
// from |in_vector|
//
// Output:
// - out_vector : Vector with the requested samples
//
// Return value : Number of copied samples in |out_vector|
//
//
// WebRtcSpl_ZerosArrayW16(...)
// WebRtcSpl_ZerosArrayW32(...)
//
// Inserts the value "zero" in all positions of a w16 and a w32 vector
// respectively.
//
// Input:
// - vector_length : Number of samples in vector
//
// Output:
// - vector : Vector containing all zeros
//
// Return value : Number of samples in vector
//
//
// WebRtcSpl_OnesArrayW16(...)
// WebRtcSpl_OnesArrayW32(...)
//
// Inserts the value "one" in all positions of a w16 and a w32 vector
// respectively.
//
// Input:
// - vector_length : Number of samples in vector
//
// Output:
// - vector : Vector containing all ones
//
// Return value : Number of samples in vector
//
//
// WebRtcSpl_MinValueW16(...)
// WebRtcSpl_MinValueW32(...)
//
// Returns the minimum value of a vector
//
// Input:
// - vector : Input vector
// - vector_length : Number of samples in vector
//
// Return value : Minimum sample value in vector
//
//
// WebRtcSpl_MaxValueW16(...)
// WebRtcSpl_MaxValueW32(...)
//
// Returns the maximum value of a vector
//
// Input:
// - vector : Input vector
// - vector_length : Number of samples in vector
//
// Return value : Maximum sample value in vector
//
//
// WebRtcSpl_MaxAbsValueW16(...)
// WebRtcSpl_MaxAbsValueW32(...)
//
// Returns the largest absolute value of a vector
//
// Input:
// - vector : Input vector
// - vector_length : Number of samples in vector
//
// Return value : Maximum absolute value in vector
//
//
// WebRtcSpl_MaxAbsIndexW16(...)
//
// Returns the vector index to the largest absolute value of a vector
//
// Input:
// - vector : Input vector
// - vector_length : Number of samples in vector
//
// Return value : Index to maximum absolute value in vector
//
//
// WebRtcSpl_MinIndexW16(...)
// WebRtcSpl_MinIndexW32(...)
//
// Returns the vector index to the minimum sample value of a vector
//
// Input:
// - vector : Input vector
// - vector_length : Number of samples in vector
//
// Return value : Index to minimum sample value in vector
//
//
// WebRtcSpl_MaxIndexW16(...)
// WebRtcSpl_MaxIndexW32(...)
//
// Returns the vector index to the maximum sample value of a vector
//
// Input:
// - vector : Input vector
// - vector_length : Number of samples in vector
//
// Return value : Index to maximum sample value in vector
//
//
// WebRtcSpl_VectorBitShiftW16(...)
// WebRtcSpl_VectorBitShiftW32(...)
//
// Bit shifts all the values in a vector up or downwards. Different calls for
// WebRtc_Word16 and WebRtc_Word32 vectors respectively.
//
// Input:
// - vector_length : Length of vector
// - in_vector : Pointer to the vector that should be bit shifted
// - right_shifts : Number of right bit shifts (negative value gives left
// shifts)
//
// Output:
// - out_vector : Pointer to the result vector (can be the same as
// |in_vector|)
//
//
// WebRtcSpl_VectorBitShiftW32ToW16(...)
//
// Bit shifts all the values in a WebRtc_Word32 vector up or downwards and
// stores the result as a WebRtc_Word16 vector
//
// Input:
// - vector_length : Length of vector
// - in_vector : Pointer to the vector that should be bit shifted
// - right_shifts : Number of right bit shifts (negative value gives left
// shifts)
//
// Output:
// - out_vector : Pointer to the result vector (can be the same as
// |in_vector|)
//
//
// WebRtcSpl_ScaleVector(...)
//
// Performs the vector operation:
// out_vector[k] = (gain*in_vector[k])>>right_shifts
//
// Input:
// - in_vector : Input vector
// - gain : Scaling gain
// - vector_length : Elements in the |in_vector|
// - right_shifts : Number of right bit shifts applied
//
// Output:
// - out_vector : Output vector (can be the same as |in_vector|)
//
//
// WebRtcSpl_ScaleVectorWithSat(...)
//
// Performs the vector operation:
// out_vector[k] = SATURATE( (gain*in_vector[k])>>right_shifts )
//
// Input:
// - in_vector : Input vector
// - gain : Scaling gain
// - vector_length : Elements in the |in_vector|
// - right_shifts : Number of right bit shifts applied
//
// Output:
// - out_vector : Output vector (can be the same as |in_vector|)
//
//
// WebRtcSpl_ScaleAndAddVectors(...)
//
// Performs the vector operation:
// out_vector[k] = (gain1*in_vector1[k])>>right_shifts1
// + (gain2*in_vector2[k])>>right_shifts2
//
// Input:
// - in_vector1 : Input vector 1
// - gain1 : Gain to be used for vector 1
// - right_shifts1 : Right bit shift to be used for vector 1
// - in_vector2 : Input vector 2
// - gain2 : Gain to be used for vector 2
// - right_shifts2 : Right bit shift to be used for vector 2
// - vector_length : Elements in the input vectors
//
// Output:
// - out_vector : Output vector
//
//
// WebRtcSpl_ScaleAndAddVectorsWithRound(...)
//
// Performs the vector operation:
//
// out_vector[k] = ((scale1*in_vector1[k]) + (scale2*in_vector2[k])
// + round_value) >> right_shifts
//
// where:
//
// round_value = (1<<right_shifts)>>1
//
// Input:
// - in_vector1 : Input vector 1
// - scale1 : Gain to be used for vector 1
// - in_vector2 : Input vector 2
// - scale2 : Gain to be used for vector 2
// - right_shifts : Number of right bit shifts to be applied
// - vector_length : Number of elements in the input vectors
//
// Output:
// - out_vector : Output vector
//
//
// WebRtcSpl_ReverseOrderMultArrayElements(...)
//
// Performs the vector operation:
// out_vector[n] = (in_vector[n]*window[-n])>>right_shifts
//
// Input:
// - in_vector : Input vector
// - window : Window vector (should be reversed). The pointer
// should be set to the last value in the vector
// - right_shifts : Number of right bit shift to be applied after the
// multiplication
// - vector_length : Number of elements in |in_vector|
//
// Output:
// - out_vector : Output vector (can be same as |in_vector|)
//
//
// WebRtcSpl_ElementwiseVectorMult(...)
//
// Performs the vector operation:
// out_vector[n] = (in_vector[n]*window[n])>>right_shifts
//
// Input:
// - in_vector : Input vector
// - window : Window vector.
// - right_shifts : Number of right bit shift to be applied after the
// multiplication
// - vector_length : Number of elements in |in_vector|
//
// Output:
// - out_vector : Output vector (can be same as |in_vector|)
//
//
// WebRtcSpl_AddVectorsAndShift(...)
//
// Performs the vector operation:
// out_vector[k] = (in_vector1[k] + in_vector2[k])>>right_shifts
//
// Input:
// - in_vector1 : Input vector 1
// - in_vector2 : Input vector 2
// - right_shifts : Number of right bit shift to be applied after the
// multiplication
// - vector_length : Number of elements in |in_vector1| and |in_vector2|
//
// Output:
// - out_vector : Output vector (can be same as |in_vector1|)
//
//
// WebRtcSpl_AddAffineVectorToVector(...)
//
// Adds an affine transformed vector to another vector |out_vector|, i.e,
// performs
// out_vector[k] += (in_vector[k]*gain+add_constant)>>right_shifts
//
// Input:
// - in_vector : Input vector
// - gain : Gain value, used to multiply the in vector with
// - add_constant : Constant value to add (usually 1<<(right_shifts-1),
// but others can be used as well
// - right_shifts : Number of right bit shifts (0-16)
// - vector_length : Number of samples in |in_vector| and |out_vector|
//
// Output:
// - out_vector : Vector with the output
//
//
// WebRtcSpl_AffineTransformVector(...)
//
// Affine transforms a vector, i.e, performs
// out_vector[k] = (in_vector[k]*gain+add_constant)>>right_shifts
//
// Input:
// - in_vector : Input vector
// - gain : Gain value, used to multiply the in vector with
// - add_constant : Constant value to add (usually 1<<(right_shifts-1),
// but others can be used as well
// - right_shifts : Number of right bit shifts (0-16)
// - vector_length : Number of samples in |in_vector| and |out_vector|
//
// Output:
// - out_vector : Vector with the output
//
//
// WebRtcSpl_AutoCorrelation(...)
//
// A 32-bit fix-point implementation of auto-correlation computation
//
// Input:
// - vector : Vector to calculate autocorrelation upon
// - vector_length : Length (in samples) of |vector|
// - order : The order up to which the autocorrelation should be
// calculated
//
// Output:
// - result_vector : auto-correlation values (values should be seen
// relative to each other since the absolute values
// might have been down shifted to avoid overflow)
//
// - scale : The number of left shifts required to obtain the
// auto-correlation in Q0
//
// Return value : Number of samples in |result_vector|, i.e., (order+1)
//
//
// WebRtcSpl_LevinsonDurbin(...)
//
// A 32-bit fix-point implementation of the Levinson-Durbin algorithm that
// does NOT use the 64 bit class
//
// Input:
// - auto_corr : Vector with autocorrelation values of length >=
// |use_order|+1
// - use_order : The LPC filter order (support up to order 20)
//
// Output:
// - lpc_coef : lpc_coef[0..use_order] LPC coefficients in Q12
// - refl_coef : refl_coef[0...use_order-1]| Reflection coefficients in
// Q15
//
// Return value : 1 for stable 0 for unstable
//
//
// WebRtcSpl_ReflCoefToLpc(...)
//
// Converts reflection coefficients |refl_coef| to LPC coefficients |lpc_coef|.
// This version is a 16 bit operation.
//
// NOTE: The 16 bit refl_coef -> lpc_coef conversion might result in a
// "slightly unstable" filter (i.e., a pole just outside the unit circle) in
// "rare" cases even if the reflection coefficients are stable.
//
// Input:
// - refl_coef : Reflection coefficients in Q15 that should be converted
// to LPC coefficients
// - use_order : Number of coefficients in |refl_coef|
//
// Output:
// - lpc_coef : LPC coefficients in Q12
//
//
// WebRtcSpl_LpcToReflCoef(...)
//
// Converts LPC coefficients |lpc_coef| to reflection coefficients |refl_coef|.
// This version is a 16 bit operation.
// The conversion is implemented by the step-down algorithm.
//
// Input:
// - lpc_coef : LPC coefficients in Q12, that should be converted to
// reflection coefficients
// - use_order : Number of coefficients in |lpc_coef|
//
// Output:
// - refl_coef : Reflection coefficients in Q15.
//
//
// WebRtcSpl_AutoCorrToReflCoef(...)
//
// Calculates reflection coefficients (16 bit) from auto-correlation values
//
// Input:
// - auto_corr : Auto-correlation values
// - use_order : Number of coefficients wanted be calculated
//
// Output:
// - refl_coef : Reflection coefficients in Q15.
//
//
// WebRtcSpl_CrossCorrelation(...)
//
// Calculates the cross-correlation between two sequences |vector1| and
// |vector2|. |vector1| is fixed and |vector2| slides as the pointer is
// increased with the amount |step_vector2|
//
// Input:
// - vector1 : First sequence (fixed throughout the correlation)
// - vector2 : Second sequence (slides |step_vector2| for each
// new correlation)
// - dim_vector : Number of samples to use in the cross-correlation
// - dim_cross_corr : Number of cross-correlations to calculate (the
// start position for |vector2| is updated for each
// new one)
// - right_shifts : Number of right bit shifts to use. This will
// become the output Q-domain.
// - step_vector2 : How many (positive or negative) steps the
// |vector2| pointer should be updated for each new
// cross-correlation value.
//
// Output:
// - cross_corr : The cross-correlation in Q(-right_shifts)
//
//
// WebRtcSpl_GetHanningWindow(...)
//
// Creates (the first half of) a Hanning window. Size must be at least 1 and
// at most 512.
//
// Input:
// - size : Length of the requested Hanning window (1 to 512)
//
// Output:
// - window : Hanning vector in Q14.
//
//
// WebRtcSpl_SqrtOfOneMinusXSquared(...)
//
// Calculates y[k] = sqrt(1 - x[k]^2) for each element of the input vector
// |in_vector|. Input and output values are in Q15.
//
// Inputs:
// - in_vector : Values to calculate sqrt(1 - x^2) of
// - vector_length : Length of vector |in_vector|
//
// Output:
// - out_vector : Output values in Q15
//
//
// WebRtcSpl_IncreaseSeed(...)
//
// Increases the seed (and returns the new value)
//
// Input:
// - seed : Seed for random calculation
//
// Output:
// - seed : Updated seed value
//
// Return value : The new seed value
//
//
// WebRtcSpl_RandU(...)
//
// Produces a uniformly distributed value in the WebRtc_Word16 range
//
// Input:
// - seed : Seed for random calculation
//
// Output:
// - seed : Updated seed value
//
// Return value : Uniformly distributed value in the range
// [Word16_MIN...Word16_MAX]
//
//
// WebRtcSpl_RandN(...)
//
// Produces a normal distributed value in the WebRtc_Word16 range
//
// Input:
// - seed : Seed for random calculation
//
// Output:
// - seed : Updated seed value
//
// Return value : N(0,1) value in the Q13 domain
//
//
// WebRtcSpl_RandUArray(...)
//
// Produces a uniformly distributed vector with elements in the WebRtc_Word16
// range
//
// Input:
// - vector_length : Samples wanted in the vector
// - seed : Seed for random calculation
//
// Output:
// - vector : Vector with the uniform values
// - seed : Updated seed value
//
// Return value : Number of samples in vector, i.e., |vector_length|
//
//
// WebRtcSpl_Sqrt(...)
//
// Returns the square root of the input value |value|. The precision of this
// function is integer precision, i.e., sqrt(8) gives 2 as answer.
// If |value| is a negative number then 0 is returned.
//
// Algorithm:
//
// A sixth order Taylor Series expansion is used here to compute the square
// root of a number y^0.5 = (1+x)^0.5
// where
// x = y-1
// = 1+(x/2)-0.5*((x/2)^2+0.5*((x/2)^3-0.625*((x/2)^4+0.875*((x/2)^5)
// 0.5 <= x < 1
//
// Input:
// - value : Value to calculate sqrt of
//
// Return value : Result of the sqrt calculation
//
//
// WebRtcSpl_SqrtFloor(...)
//
// Returns the square root of the input value |value|. The precision of this
// function is rounding down integer precision, i.e., sqrt(8) gives 2 as answer.
// If |value| is a negative number then 0 is returned.
//
// Algorithm:
//
// An iterative 4 cylce/bit routine
//
// Input:
// - value : Value to calculate sqrt of
//
// Return value : Result of the sqrt calculation
//
//
// WebRtcSpl_DivU32U16(...)
//
// Divides a WebRtc_UWord32 |num| by a WebRtc_UWord16 |den|.
//
// If |den|==0, (WebRtc_UWord32)0xFFFFFFFF is returned.
//
// Input:
// - num : Numerator
// - den : Denominator
//
// Return value : Result of the division (as a WebRtc_UWord32), i.e., the
// integer part of num/den.
//
//
// WebRtcSpl_DivW32W16(...)
//
// Divides a WebRtc_Word32 |num| by a WebRtc_Word16 |den|.
//
// If |den|==0, (WebRtc_Word32)0x7FFFFFFF is returned.
//
// Input:
// - num : Numerator
// - den : Denominator
//
// Return value : Result of the division (as a WebRtc_Word32), i.e., the
// integer part of num/den.
//
//
// WebRtcSpl_DivW32W16ResW16(...)
//
// Divides a WebRtc_Word32 |num| by a WebRtc_Word16 |den|, assuming that the
// result is less than 32768, otherwise an unpredictable result will occur.
//
// If |den|==0, (WebRtc_Word16)0x7FFF is returned.
//
// Input:
// - num : Numerator
// - den : Denominator
//
// Return value : Result of the division (as a WebRtc_Word16), i.e., the
// integer part of num/den.
//
//
// WebRtcSpl_DivResultInQ31(...)
//
// Divides a WebRtc_Word32 |num| by a WebRtc_Word16 |den|, assuming that the
// absolute value of the denominator is larger than the numerator, otherwise
// an unpredictable result will occur.
//
// Input:
// - num : Numerator
// - den : Denominator
//
// Return value : Result of the division in Q31.
//
//
// WebRtcSpl_DivW32HiLow(...)
//
// Divides a WebRtc_Word32 |num| by a denominator in hi, low format. The
// absolute value of the denominator has to be larger (or equal to) the
// numerator.
//
// Input:
// - num : Numerator
// - den_hi : High part of denominator
// - den_low : Low part of denominator
//
// Return value : Divided value in Q31
//
//
// WebRtcSpl_Energy(...)
//
// Calculates the energy of a vector
//
// Input:
// - vector : Vector which the energy should be calculated on
// - vector_length : Number of samples in vector
//
// Output:
// - scale_factor : Number of left bit shifts needed to get the physical
// energy value, i.e, to get the Q0 value
//
// Return value : Energy value in Q(-|scale_factor|)
//
//
// WebRtcSpl_FilterAR(...)
//
// Performs a 32-bit AR filtering on a vector in Q12
//
// Input:
// - ar_coef : AR-coefficient vector (values in Q12),
// ar_coef[0] must be 4096.
// - ar_coef_length : Number of coefficients in |ar_coef|.
// - in_vector : Vector to be filtered.
// - in_vector_length : Number of samples in |in_vector|.
// - filter_state : Current state (higher part) of the filter.
// - filter_state_length : Length (in samples) of |filter_state|.
// - filter_state_low : Current state (lower part) of the filter.
// - filter_state_low_length : Length (in samples) of |filter_state_low|.
// - out_vector_low_length : Maximum length (in samples) of
// |out_vector_low|.
//
// Output:
// - filter_state : Updated state (upper part) vector.
// - filter_state_low : Updated state (lower part) vector.
// - out_vector : Vector containing the upper part of the
// filtered values.
// - out_vector_low : Vector containing the lower part of the
// filtered values.
//
// Return value : Number of samples in the |out_vector|.
//
//
// WebRtcSpl_FilterMAFastQ12(...)
//
// Performs a MA filtering on a vector in Q12
//
// Input:
// - in_vector : Input samples (state in positions
// in_vector[-order] .. in_vector[-1])
// - ma_coef : Filter coefficients (in Q12)
// - ma_coef_length : Number of B coefficients (order+1)
// - vector_length : Number of samples to be filtered
//
// Output:
// - out_vector : Filtered samples
//
//
// WebRtcSpl_DotProductWithScale(...)
//
// Calculates the dot product between two (WebRtc_Word16) vectors
//
// Input:
// - vector1 : Vector 1
// - vector2 : Vector 2
// - vector_length : Number of samples used in the dot product
// - scaling : The number of right bit shifts to apply on each term
// during calculation to avoid overflow, i.e., the
// output will be in Q(-|scaling|)
//
// Return value : The dot product in Q(-scaling)
//
//
// WebRtcSpl_ComplexIFFT(...)
//
// Complex Inverse FFT
//
// Computes an inverse complex 2^|stages|-point FFT on the input vector, which
// is in bit-reversed order. The original content of the vector is destroyed in
// the process, since the input is overwritten by the output, normal-ordered,
// FFT vector. With X as the input complex vector, y as the output complex
// vector and with M = 2^|stages|, the following is computed:
//
// M-1
// y(k) = sum[X(i)*[cos(2*pi*i*k/M) + j*sin(2*pi*i*k/M)]]
// i=0
//
// The implementations are optimized for speed, not for code size. It uses the
// decimation-in-time algorithm with radix-2 butterfly technique.
//
// Input:
// - vector : In pointer to complex vector containing 2^|stages|
// real elements interleaved with 2^|stages| imaginary
// elements.
// [ReImReImReIm....]
// The elements are in Q(-scale) domain, see more on Return
// Value below.
//
// - stages : Number of FFT stages. Must be at least 3 and at most 10,
// since the table WebRtcSpl_kSinTable1024[] is 1024
// elements long.
//
// - mode : This parameter gives the user to choose how the FFT
// should work.
// mode==0: Low-complexity and Low-accuracy mode
// mode==1: High-complexity and High-accuracy mode
//
// Output:
// - vector : Out pointer to the FFT vector (the same as input).
//
// Return Value : The scale value that tells the number of left bit shifts
// that the elements in the |vector| should be shifted with
// in order to get Q0 values, i.e. the physically correct
// values. The scale parameter is always 0 or positive,
// except if N>1024 (|stages|>10), which returns a scale
// value of -1, indicating error.
//
//
// WebRtcSpl_ComplexFFT(...)
//
// Complex FFT
//
// Computes a complex 2^|stages|-point FFT on the input vector, which is in
// bit-reversed order. The original content of the vector is destroyed in
// the process, since the input is overwritten by the output, normal-ordered,
// FFT vector. With x as the input complex vector, Y as the output complex
// vector and with M = 2^|stages|, the following is computed:
//
// M-1
// Y(k) = 1/M * sum[x(i)*[cos(2*pi*i*k/M) + j*sin(2*pi*i*k/M)]]
// i=0
//
// The implementations are optimized for speed, not for code size. It uses the
// decimation-in-time algorithm with radix-2 butterfly technique.
//
// This routine prevents overflow by scaling by 2 before each FFT stage. This is
// a fixed scaling, for proper normalization - there will be log2(n) passes, so
// this results in an overall factor of 1/n, distributed to maximize arithmetic
// accuracy.
//
// Input:
// - vector : In pointer to complex vector containing 2^|stages| real
// elements interleaved with 2^|stages| imaginary elements.
// [ReImReImReIm....]
// The output is in the Q0 domain.
//
// - stages : Number of FFT stages. Must be at least 3 and at most 10,
// since the table WebRtcSpl_kSinTable1024[] is 1024
// elements long.
//
// - mode : This parameter gives the user to choose how the FFT
// should work.
// mode==0: Low-complexity and Low-accuracy mode
// mode==1: High-complexity and High-accuracy mode
//
// Output:
// - vector : The output FFT vector is in the Q0 domain.
//
// Return value : The scale parameter is always 0, except if N>1024,
// which returns a scale value of -1, indicating error.
//
//
// WebRtcSpl_AnalysisQMF(...)
//
// Splits a 0-2*F Hz signal into two sub bands: 0-F Hz and F-2*F Hz. The
// current version has F = 8000, therefore, a super-wideband audio signal is
// split to lower-band 0-8 kHz and upper-band 8-16 kHz.
//
// Input:
// - in_data : Wide band speech signal, 320 samples (10 ms)
//
// Input & Output:
// - filter_state1 : Filter state for first All-pass filter
// - filter_state2 : Filter state for second All-pass filter
//
// Output:
// - low_band : Lower-band signal 0-8 kHz band, 160 samples (10 ms)
// - high_band : Upper-band signal 8-16 kHz band (flipped in frequency
// domain), 160 samples (10 ms)
//
//
// WebRtcSpl_SynthesisQMF(...)
//
// Combines the two sub bands (0-F and F-2*F Hz) into a signal of 0-2*F
// Hz, (current version has F = 8000 Hz). So the filter combines lower-band
// (0-8 kHz) and upper-band (8-16 kHz) channels to obtain super-wideband 0-16
// kHz audio.
//
// Input:
// - low_band : The signal with the 0-8 kHz band, 160 samples (10 ms)
// - high_band : The signal with the 8-16 kHz band, 160 samples (10 ms)
//
// Input & Output:
// - filter_state1 : Filter state for first All-pass filter
// - filter_state2 : Filter state for second All-pass filter
//
// Output:
// - out_data : Super-wideband speech signal, 0-16 kHz
//
// WebRtc_Word16 WebRtcSpl_SatW32ToW16(...)
//
// This function saturates a 32-bit word into a 16-bit word.
//
// Input:
// - value32 : The value of a 32-bit word.
//
// Output:
// - out16 : the saturated 16-bit word.
//
// int32_t WebRtc_MulAccumW16(...)
//
// This function multiply a 16-bit word by a 16-bit word, and accumulate this
// value to a 32-bit integer.
//
// Input:
// - a : The value of the first 16-bit word.
// - b : The value of the second 16-bit word.
// - c : The value of an 32-bit integer.
//
// Return Value: The value of a * b + c.
//
// WebRtc_Word16 WebRtcSpl_get_version(...)
//
// This function gives the version string of the Signal Processing Library.
//
// Input:
// - length_in_bytes : The size of Allocated space (in Bytes) where
// the version number is written to (in string format).
//
// Output:
// - version : Pointer to a buffer where the version number is written to.
//