Add copy of opus library in deps/third_party.

opus/silk/float/prefilter_FLP.c

+/***********************************************************************
+Copyright (c) 2006-2011, Skype Limited. All rights reserved.
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+- Redistributions of source code must retain the above copyright notice,
+this list of conditions and the following disclaimer.
+- Redistributions in binary form must reproduce the above copyright
+notice, this list of conditions and the following disclaimer in the
+documentation and/or other materials provided with the distribution.
+- Neither the name of Internet Society, IETF or IETF Trust, nor the 
+names of specific contributors, may be used to endorse or promote
+products derived from this software without specific prior written
+permission.
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS “AS IS”
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+***********************************************************************/
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "main_FLP.h"
+#include "tuning_parameters.h"
+
+/*
+* Prefilter for finding Quantizer input signal
+*/
+static inline void silk_prefilt_FLP(
+    silk_prefilter_state_FLP    *P,                 /* I/O state */
+    silk_float                  st_res[],           /* I */
+    silk_float                  xw[],               /* O */
+    silk_float                  *HarmShapeFIR,      /* I */
+    silk_float                  Tilt,               /* I */
+    silk_float                  LF_MA_shp,          /* I */
+    silk_float                  LF_AR_shp,          /* I */
+    opus_int                    lag,                /* I */
+    opus_int                    length              /* I */
+);
+
+void silk_warped_LPC_analysis_filter_FLP(
+          silk_float                 state[],            /* I/O  State [order + 1]                       */
+          silk_float                 res[],              /* O    Residual signal [length]                */
+    const silk_float                 coef[],             /* I    Coefficients [order]                    */
+    const silk_float                 input[],            /* I    Input signal [length]                   */
+    const silk_float                 lambda,             /* I    Warping factor                          */
+    const opus_int                   length,             /* I    Length of input signal                  */
+    const opus_int                   order               /* I    Filter order (even)                     */
+)
+{
+    opus_int     n, i;
+    silk_float   acc, tmp1, tmp2;
+
+    /* Order must be even */
+    silk_assert( ( order & 1 ) == 0 );
+
+    for( n = 0; n < length; n++ ) {
+        /* Output of lowpass section */
+        tmp2 = state[ 0 ] + lambda * state[ 1 ];
+        state[ 0 ] = input[ n ];
+        /* Output of allpass section */
+        tmp1 = state[ 1 ] + lambda * ( state[ 2 ] - tmp2 );
+        state[ 1 ] = tmp2;
+        acc = coef[ 0 ] * tmp2;
+        /* Loop over allpass sections */
+        for( i = 2; i < order; i += 2 ) {
+            /* Output of allpass section */
+            tmp2 = state[ i ] + lambda * ( state[ i + 1 ] - tmp1 );
+            state[ i ] = tmp1;
+            acc += coef[ i - 1 ] * tmp1;
+            /* Output of allpass section */
+            tmp1 = state[ i + 1 ] + lambda * ( state[ i + 2 ] - tmp2 );
+            state[ i + 1 ] = tmp2;
+            acc += coef[ i ] * tmp2;
+        }
+        state[ order ] = tmp1;
+        acc += coef[ order - 1 ] * tmp1;
+        res[ n ] = input[ n ] - acc;
+    }
+}
+
+/*
+* silk_prefilter. Main prefilter function
+*/
+void silk_prefilter_FLP(
+    silk_encoder_state_FLP          *psEnc,                             /* I/O  Encoder state FLP                           */
+    const silk_encoder_control_FLP  *psEncCtrl,                         /* I    Encoder control FLP                         */
+    silk_float                      xw[],                               /* O    Weighted signal                             */
+    const silk_float                x[]                                 /* I    Speech signal                               */
+)
+{
+    silk_prefilter_state_FLP *P = &psEnc->sPrefilt;
+    opus_int   j, k, lag;
+    silk_float HarmShapeGain, Tilt, LF_MA_shp, LF_AR_shp;
+    silk_float B[ 2 ];
+    const silk_float *AR1_shp;
+    const silk_float *px;
+    silk_float *pxw;
+    silk_float HarmShapeFIR[ 3 ];
+    silk_float st_res[ MAX_SUB_FRAME_LENGTH + MAX_LPC_ORDER ];
+
+    /* Set up pointers */
+    px  = x;
+    pxw = xw;
+    lag = P->lagPrev;
+    for( k = 0; k < psEnc->sCmn.nb_subfr; k++ ) {
+        /* Update Variables that change per sub frame */
+        if( psEnc->sCmn.indices.signalType == TYPE_VOICED ) {
+            lag = psEncCtrl->pitchL[ k ];
+        }
+
+        /* Noise shape parameters */
+        HarmShapeGain = psEncCtrl->HarmShapeGain[ k ] * ( 1.0f - psEncCtrl->HarmBoost[ k ] );
+        HarmShapeFIR[ 0 ] = 0.25f               * HarmShapeGain;
+        HarmShapeFIR[ 1 ] = 32767.0f / 65536.0f * HarmShapeGain;
+        HarmShapeFIR[ 2 ] = 0.25f               * HarmShapeGain;
+        Tilt      =  psEncCtrl->Tilt[ k ];
+        LF_MA_shp =  psEncCtrl->LF_MA_shp[ k ];
+        LF_AR_shp =  psEncCtrl->LF_AR_shp[ k ];
+        AR1_shp   = &psEncCtrl->AR1[ k * MAX_SHAPE_LPC_ORDER ];
+
+        /* Short term FIR filtering */
+        silk_warped_LPC_analysis_filter_FLP( P->sAR_shp, st_res, AR1_shp, px,
+            (silk_float)psEnc->sCmn.warping_Q16 / 65536.0f, psEnc->sCmn.subfr_length, psEnc->sCmn.shapingLPCOrder );
+
+        /* Reduce (mainly) low frequencies during harmonic emphasis */
+        B[ 0 ] =  psEncCtrl->GainsPre[ k ];
+        B[ 1 ] = -psEncCtrl->GainsPre[ k ] *
+            ( psEncCtrl->HarmBoost[ k ] * HarmShapeGain + INPUT_TILT + psEncCtrl->coding_quality * HIGH_RATE_INPUT_TILT );
+        pxw[ 0 ] = B[ 0 ] * st_res[ 0 ] + B[ 1 ] * P->sHarmHP;
+        for( j = 1; j < psEnc->sCmn.subfr_length; j++ ) {
+            pxw[ j ] = B[ 0 ] * st_res[ j ] + B[ 1 ] * st_res[ j - 1 ];
+        }
+        P->sHarmHP = st_res[ psEnc->sCmn.subfr_length - 1 ];
+
+        silk_prefilt_FLP( P, pxw, pxw, HarmShapeFIR, Tilt, LF_MA_shp, LF_AR_shp, lag, psEnc->sCmn.subfr_length );
+
+        px  += psEnc->sCmn.subfr_length;
+        pxw += psEnc->sCmn.subfr_length;
+    }
+    P->lagPrev = psEncCtrl->pitchL[ psEnc->sCmn.nb_subfr - 1 ];
+}
+
+/*
+* Prefilter for finding Quantizer input signal
+*/
+static inline void silk_prefilt_FLP(
+    silk_prefilter_state_FLP    *P,                 /* I/O state */
+    silk_float                  st_res[],           /* I */
+    silk_float                  xw[],               /* O */
+    silk_float                  *HarmShapeFIR,      /* I */
+    silk_float                  Tilt,               /* I */
+    silk_float                  LF_MA_shp,          /* I */
+    silk_float                  LF_AR_shp,          /* I */
+    opus_int                    lag,                /* I */
+    opus_int                    length              /* I */
+)
+{
+    opus_int   i;
+    opus_int   idx, LTP_shp_buf_idx;
+    silk_float n_Tilt, n_LF, n_LTP;
+    silk_float sLF_AR_shp, sLF_MA_shp;
+    silk_float *LTP_shp_buf;
+
+    /* To speed up use temp variables instead of using the struct */
+    LTP_shp_buf     = P->sLTP_shp;
+    LTP_shp_buf_idx = P->sLTP_shp_buf_idx;
+    sLF_AR_shp      = P->sLF_AR_shp;
+    sLF_MA_shp      = P->sLF_MA_shp;
+
+    for( i = 0; i < length; i++ ) {
+        if( lag > 0 ) {
+            silk_assert( HARM_SHAPE_FIR_TAPS == 3 );
+            idx = lag + LTP_shp_buf_idx;
+            n_LTP  = LTP_shp_buf[ ( idx - HARM_SHAPE_FIR_TAPS / 2 - 1) & LTP_MASK ] * HarmShapeFIR[ 0 ];
+            n_LTP += LTP_shp_buf[ ( idx - HARM_SHAPE_FIR_TAPS / 2    ) & LTP_MASK ] * HarmShapeFIR[ 1 ];
+            n_LTP += LTP_shp_buf[ ( idx - HARM_SHAPE_FIR_TAPS / 2 + 1) & LTP_MASK ] * HarmShapeFIR[ 2 ];
+        } else {
+            n_LTP = 0;
+        }
+
+        n_Tilt = sLF_AR_shp * Tilt;
+        n_LF   = sLF_AR_shp * LF_AR_shp + sLF_MA_shp * LF_MA_shp;
+
+        sLF_AR_shp = st_res[ i ] - n_Tilt;
+        sLF_MA_shp = sLF_AR_shp - n_LF;
+
+        LTP_shp_buf_idx = ( LTP_shp_buf_idx - 1 ) & LTP_MASK;
+        LTP_shp_buf[ LTP_shp_buf_idx ] = sLF_MA_shp;
+
+        xw[ i ] = sLF_MA_shp - n_LTP;
+    }
+    /* Copy temp variable back to state */
+    P->sLF_AR_shp       = sLF_AR_shp;
+    P->sLF_MA_shp       = sLF_MA_shp;
+    P->sLTP_shp_buf_idx = LTP_shp_buf_idx;
+}