Add copy of opus library in deps/third_party.

opus/silk/float/find_pitch_lags_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 <stdlib.h>
+#include "main_FLP.h"
+#include "tuning_parameters.h"
+
+void silk_find_pitch_lags_FLP(
+    silk_encoder_state_FLP          *psEnc,                             /* I/O  Encoder state FLP                           */
+    silk_encoder_control_FLP        *psEncCtrl,                         /* I/O  Encoder control FLP                         */
+    silk_float                      res[],                              /* O    Residual                                    */
+    const silk_float                x[]                                 /* I    Speech signal                               */
+)
+{
+    opus_int   buf_len;
+    silk_float thrhld, res_nrg;
+    const silk_float *x_buf_ptr, *x_buf;
+    silk_float auto_corr[ MAX_FIND_PITCH_LPC_ORDER + 1 ];
+    silk_float A[         MAX_FIND_PITCH_LPC_ORDER ];
+    silk_float refl_coef[ MAX_FIND_PITCH_LPC_ORDER ];
+    silk_float Wsig[      FIND_PITCH_LPC_WIN_MAX ];
+    silk_float *Wsig_ptr;
+
+    /******************************************/
+    /* Set up buffer lengths etc based on Fs  */
+    /******************************************/
+    buf_len = psEnc->sCmn.la_pitch + psEnc->sCmn.frame_length + psEnc->sCmn.ltp_mem_length;
+
+    /* Safty check */
+    silk_assert( buf_len >= psEnc->sCmn.pitch_LPC_win_length );
+
+    x_buf = x - psEnc->sCmn.ltp_mem_length;
+
+    /******************************************/
+    /* Estimate LPC AR coeficients            */
+    /******************************************/
+
+    /* Calculate windowed signal */
+
+    /* First LA_LTP samples */
+    x_buf_ptr = x_buf + buf_len - psEnc->sCmn.pitch_LPC_win_length;
+    Wsig_ptr  = Wsig;
+    silk_apply_sine_window_FLP( Wsig_ptr, x_buf_ptr, 1, psEnc->sCmn.la_pitch );
+
+    /* Middle non-windowed samples */
+    Wsig_ptr  += psEnc->sCmn.la_pitch;
+    x_buf_ptr += psEnc->sCmn.la_pitch;
+    silk_memcpy( Wsig_ptr, x_buf_ptr, ( psEnc->sCmn.pitch_LPC_win_length - ( psEnc->sCmn.la_pitch << 1 ) ) * sizeof( silk_float ) );
+
+    /* Last LA_LTP samples */
+    Wsig_ptr  += psEnc->sCmn.pitch_LPC_win_length - ( psEnc->sCmn.la_pitch << 1 );
+    x_buf_ptr += psEnc->sCmn.pitch_LPC_win_length - ( psEnc->sCmn.la_pitch << 1 );
+    silk_apply_sine_window_FLP( Wsig_ptr, x_buf_ptr, 2, psEnc->sCmn.la_pitch );
+
+    /* Calculate autocorrelation sequence */
+    silk_autocorrelation_FLP( auto_corr, Wsig, psEnc->sCmn.pitch_LPC_win_length, psEnc->sCmn.pitchEstimationLPCOrder + 1 );
+
+    /* Add white noise, as a fraction of the energy */
+    auto_corr[ 0 ] += auto_corr[ 0 ] * FIND_PITCH_WHITE_NOISE_FRACTION + 1;
+
+    /* Calculate the reflection coefficients using Schur */
+    res_nrg = silk_schur_FLP( refl_coef, auto_corr, psEnc->sCmn.pitchEstimationLPCOrder );
+
+    /* Prediction gain */
+    psEncCtrl->predGain = auto_corr[ 0 ] / silk_max_float( res_nrg, 1.0f );
+
+    /* Convert reflection coefficients to prediction coefficients */
+    silk_k2a_FLP( A, refl_coef, psEnc->sCmn.pitchEstimationLPCOrder );
+
+    /* Bandwidth expansion */
+    silk_bwexpander_FLP( A, psEnc->sCmn.pitchEstimationLPCOrder, FIND_PITCH_BANDWITH_EXPANSION );
+
+    /*****************************************/
+    /* LPC analysis filtering                */
+    /*****************************************/
+    silk_LPC_analysis_filter_FLP( res, A, x_buf, buf_len, psEnc->sCmn.pitchEstimationLPCOrder );
+
+    if( psEnc->sCmn.indices.signalType != TYPE_NO_VOICE_ACTIVITY && psEnc->sCmn.first_frame_after_reset == 0 ) {
+        /* Threshold for pitch estimator */
+        thrhld  = 0.6f;
+        thrhld -= 0.004f * psEnc->sCmn.pitchEstimationLPCOrder;
+        thrhld -= 0.1f   * psEnc->sCmn.speech_activity_Q8 * ( 1.0f /  256.0f );
+        thrhld -= 0.15f  * (psEnc->sCmn.prevSignalType >> 1);
+        thrhld -= 0.1f   * psEnc->sCmn.input_tilt_Q15 * ( 1.0f / 32768.0f );
+
+        /*****************************************/
+        /* Call Pitch estimator                  */
+        /*****************************************/
+        if( silk_pitch_analysis_core_FLP( res, psEncCtrl->pitchL, &psEnc->sCmn.indices.lagIndex,
+            &psEnc->sCmn.indices.contourIndex, &psEnc->LTPCorr, psEnc->sCmn.prevLag, psEnc->sCmn.pitchEstimationThreshold_Q16 / 65536.0f,
+            thrhld, psEnc->sCmn.fs_kHz, psEnc->sCmn.pitchEstimationComplexity, psEnc->sCmn.nb_subfr ) == 0 )
+        {
+            psEnc->sCmn.indices.signalType = TYPE_VOICED;
+        } else {
+            psEnc->sCmn.indices.signalType = TYPE_UNVOICED;
+        }
+    } else {
+        silk_memset( psEncCtrl->pitchL, 0, sizeof( psEncCtrl->pitchL ) );
+        psEnc->sCmn.indices.lagIndex = 0;
+        psEnc->sCmn.indices.contourIndex = 0;
+        psEnc->LTPCorr = 0;
+    }
+}