Create local copy of Opus v1.1.2

webrtc/modules/audio_coding/codecs/opus/opus/src/silk/fixed/find_LTP_FIX.c

Index: webrtc/modules/audio_coding/codecs/opus/opus/src/silk/fixed/find_LTP_FIX.c
diff --git a/webrtc/modules/audio_coding/codecs/opus/opus/src/silk/fixed/find_LTP_FIX.c b/webrtc/modules/audio_coding/codecs/opus/opus/src/silk/fixed/find_LTP_FIX.c
new file mode 100644
index 0000000000000000000000000000000000000000..1314a281375bd69c7270ca25fdd91e88e38c0c76
--- /dev/null
+++ b/webrtc/modules/audio_coding/codecs/opus/opus/src/silk/fixed/find_LTP_FIX.c
@@ -0,0 +1,245 @@
+/***********************************************************************
+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_FIX.h"
+#include "tuning_parameters.h"
+
+/* Head room for correlations */
+#define LTP_CORRS_HEAD_ROOM                             2
+
+void silk_fit_LTP(
+    opus_int32 LTP_coefs_Q16[ LTP_ORDER ],
+    opus_int16 LTP_coefs_Q14[ LTP_ORDER ]
+);
+
+void silk_find_LTP_FIX(
+    opus_int16                      b_Q14[ MAX_NB_SUBFR * LTP_ORDER ],      /* O    LTP coefs                                                                   */
+    opus_int32                      WLTP[ MAX_NB_SUBFR * LTP_ORDER * LTP_ORDER ], /* O    Weight for LTP quantization                                           */
+    opus_int                        *LTPredCodGain_Q7,                      /* O    LTP coding gain                                                             */
+    const opus_int16                r_lpc[],                                /* I    residual signal after LPC signal + state for first 10 ms                    */
+    const opus_int                  lag[ MAX_NB_SUBFR ],                    /* I    LTP lags                                                                    */
+    const opus_int32                Wght_Q15[ MAX_NB_SUBFR ],               /* I    weights                                                                     */
+    const opus_int                  subfr_length,                           /* I    subframe length                                                             */
+    const opus_int                  nb_subfr,                               /* I    number of subframes                                                         */
+    const opus_int                  mem_offset,                             /* I    number of samples in LTP memory                                             */
+    opus_int                        corr_rshifts[ MAX_NB_SUBFR ],           /* O    right shifts applied to correlations                                        */
+    int                             arch                                    /* I    Run-time architecture                                                       */
+)
+{
+    opus_int   i, k, lshift;
+    const opus_int16 *r_ptr, *lag_ptr;
+    opus_int16 *b_Q14_ptr;
+
+    opus_int32 regu;
+    opus_int32 *WLTP_ptr;
+    opus_int32 b_Q16[ LTP_ORDER ], delta_b_Q14[ LTP_ORDER ], d_Q14[ MAX_NB_SUBFR ], nrg[ MAX_NB_SUBFR ], g_Q26;
+    opus_int32 w[ MAX_NB_SUBFR ], WLTP_max, max_abs_d_Q14, max_w_bits;
+
+    opus_int32 temp32, denom32;
+    opus_int   extra_shifts;
+    opus_int   rr_shifts, maxRshifts, maxRshifts_wxtra, LZs;
+    opus_int32 LPC_res_nrg, LPC_LTP_res_nrg, div_Q16;
+    opus_int32 Rr[ LTP_ORDER ], rr[ MAX_NB_SUBFR ];
+    opus_int32 wd, m_Q12;
+
+    b_Q14_ptr = b_Q14;
+    WLTP_ptr  = WLTP;
+    r_ptr     = &r_lpc[ mem_offset ];
+    for( k = 0; k < nb_subfr; k++ ) {
+        lag_ptr = r_ptr - ( lag[ k ] + LTP_ORDER / 2 );
+
+        silk_sum_sqr_shift( &rr[ k ], &rr_shifts, r_ptr, subfr_length ); /* rr[ k ] in Q( -rr_shifts ) */
+
+        /* Assure headroom */
+        LZs = silk_CLZ32( rr[k] );
+        if( LZs < LTP_CORRS_HEAD_ROOM ) {
+            rr[ k ] = silk_RSHIFT_ROUND( rr[ k ], LTP_CORRS_HEAD_ROOM - LZs );
+            rr_shifts += ( LTP_CORRS_HEAD_ROOM - LZs );
+        }
+        corr_rshifts[ k ] = rr_shifts;
+        silk_corrMatrix_FIX( lag_ptr, subfr_length, LTP_ORDER, LTP_CORRS_HEAD_ROOM, WLTP_ptr, &corr_rshifts[ k ], arch );  /* WLTP_fix_ptr in Q( -corr_rshifts[ k ] ) */
+
+        /* The correlation vector always has lower max abs value than rr and/or RR so head room is assured */
+        silk_corrVector_FIX( lag_ptr, r_ptr, subfr_length, LTP_ORDER, Rr, corr_rshifts[ k ], arch );  /* Rr_fix_ptr   in Q( -corr_rshifts[ k ] ) */
+        if( corr_rshifts[ k ] > rr_shifts ) {
+            rr[ k ] = silk_RSHIFT( rr[ k ], corr_rshifts[ k ] - rr_shifts ); /* rr[ k ] in Q( -corr_rshifts[ k ] ) */
+        }
+        silk_assert( rr[ k ] >= 0 );
+
+        regu = 1;
+        regu = silk_SMLAWB( regu, rr[ k ], SILK_FIX_CONST( LTP_DAMPING/3, 16 ) );
+        regu = silk_SMLAWB( regu, matrix_ptr( WLTP_ptr, 0, 0, LTP_ORDER ), SILK_FIX_CONST( LTP_DAMPING/3, 16 ) );
+        regu = silk_SMLAWB( regu, matrix_ptr( WLTP_ptr, LTP_ORDER-1, LTP_ORDER-1, LTP_ORDER ), SILK_FIX_CONST( LTP_DAMPING/3, 16 ) );
+        silk_regularize_correlations_FIX( WLTP_ptr, &rr[k], regu, LTP_ORDER );
+
+        silk_solve_LDL_FIX( WLTP_ptr, LTP_ORDER, Rr, b_Q16 ); /* WLTP_fix_ptr and Rr_fix_ptr both in Q(-corr_rshifts[k]) */
+
+        /* Limit and store in Q14 */
+        silk_fit_LTP( b_Q16, b_Q14_ptr );
+
+        /* Calculate residual energy */
+        nrg[ k ] = silk_residual_energy16_covar_FIX( b_Q14_ptr, WLTP_ptr, Rr, rr[ k ], LTP_ORDER, 14 ); /* nrg_fix in Q( -corr_rshifts[ k ] ) */
+
+        /* temp = Wght[ k ] / ( nrg[ k ] * Wght[ k ] + 0.01f * subfr_length ); */
+        extra_shifts = silk_min_int( corr_rshifts[ k ], LTP_CORRS_HEAD_ROOM );
+        denom32 = silk_LSHIFT_SAT32( silk_SMULWB( nrg[ k ], Wght_Q15[ k ] ), 1 + extra_shifts ) + /* Q( -corr_rshifts[ k ] + extra_shifts ) */
+            silk_RSHIFT( silk_SMULWB( (opus_int32)subfr_length, 655 ), corr_rshifts[ k ] - extra_shifts );    /* Q( -corr_rshifts[ k ] + extra_shifts ) */
+        denom32 = silk_max( denom32, 1 );
+        silk_assert( ((opus_int64)Wght_Q15[ k ] << 16 ) < silk_int32_MAX );                       /* Wght always < 0.5 in Q0 */
+        temp32 = silk_DIV32( silk_LSHIFT( (opus_int32)Wght_Q15[ k ], 16 ), denom32 );             /* Q( 15 + 16 + corr_rshifts[k] - extra_shifts ) */
+        temp32 = silk_RSHIFT( temp32, 31 + corr_rshifts[ k ] - extra_shifts - 26 );               /* Q26 */
+
+        /* Limit temp such that the below scaling never wraps around */
+        WLTP_max = 0;
+        for( i = 0; i < LTP_ORDER * LTP_ORDER; i++ ) {
+            WLTP_max = silk_max( WLTP_ptr[ i ], WLTP_max );
+        }
+        lshift = silk_CLZ32( WLTP_max ) - 1 - 3; /* keep 3 bits free for vq_nearest_neighbor_fix */
+        silk_assert( 26 - 18 + lshift >= 0 );
+        if( 26 - 18 + lshift < 31 ) {
+            temp32 = silk_min_32( temp32, silk_LSHIFT( (opus_int32)1, 26 - 18 + lshift ) );
+        }
+
+        silk_scale_vector32_Q26_lshift_18( WLTP_ptr, temp32, LTP_ORDER * LTP_ORDER ); /* WLTP_ptr in Q( 18 - corr_rshifts[ k ] ) */
+
+        w[ k ] = matrix_ptr( WLTP_ptr, LTP_ORDER/2, LTP_ORDER/2, LTP_ORDER ); /* w in Q( 18 - corr_rshifts[ k ] ) */
+        silk_assert( w[k] >= 0 );
+
+        r_ptr     += subfr_length;
+        b_Q14_ptr += LTP_ORDER;
+        WLTP_ptr  += LTP_ORDER * LTP_ORDER;
+    }
+
+    maxRshifts = 0;
+    for( k = 0; k < nb_subfr; k++ ) {
+        maxRshifts = silk_max_int( corr_rshifts[ k ], maxRshifts );
+    }
+
+    /* Compute LTP coding gain */
+    if( LTPredCodGain_Q7 != NULL ) {
+        LPC_LTP_res_nrg = 0;
+        LPC_res_nrg     = 0;
+        silk_assert( LTP_CORRS_HEAD_ROOM >= 2 ); /* Check that no overflow will happen when adding */
+        for( k = 0; k < nb_subfr; k++ ) {
+            LPC_res_nrg     = silk_ADD32( LPC_res_nrg,     silk_RSHIFT( silk_ADD32( silk_SMULWB(  rr[ k ], Wght_Q15[ k ] ), 1 ), 1 + ( maxRshifts - corr_rshifts[ k ] ) ) ); /* Q( -maxRshifts ) */
+            LPC_LTP_res_nrg = silk_ADD32( LPC_LTP_res_nrg, silk_RSHIFT( silk_ADD32( silk_SMULWB( nrg[ k ], Wght_Q15[ k ] ), 1 ), 1 + ( maxRshifts - corr_rshifts[ k ] ) ) ); /* Q( -maxRshifts ) */
+        }
+        LPC_LTP_res_nrg = silk_max( LPC_LTP_res_nrg, 1 ); /* avoid division by zero */
+
+        div_Q16 = silk_DIV32_varQ( LPC_res_nrg, LPC_LTP_res_nrg, 16 );
+        *LTPredCodGain_Q7 = ( opus_int )silk_SMULBB( 3, silk_lin2log( div_Q16 ) - ( 16 << 7 ) );
+
+        silk_assert( *LTPredCodGain_Q7 == ( opus_int )silk_SAT16( silk_MUL( 3, silk_lin2log( div_Q16 ) - ( 16 << 7 ) ) ) );
+    }
+
+    /* smoothing */
+    /* d = sum( B, 1 ); */
+    b_Q14_ptr = b_Q14;
+    for( k = 0; k < nb_subfr; k++ ) {
+        d_Q14[ k ] = 0;
+        for( i = 0; i < LTP_ORDER; i++ ) {
+            d_Q14[ k ] += b_Q14_ptr[ i ];
+        }
+        b_Q14_ptr += LTP_ORDER;
+    }
+
+    /* m = ( w * d' ) / ( sum( w ) + 1e-3 ); */
+
+    /* Find maximum absolute value of d_Q14 and the bits used by w in Q0 */
+    max_abs_d_Q14 = 0;
+    max_w_bits    = 0;
+    for( k = 0; k < nb_subfr; k++ ) {
+        max_abs_d_Q14 = silk_max_32( max_abs_d_Q14, silk_abs( d_Q14[ k ] ) );
+        /* w[ k ] is in Q( 18 - corr_rshifts[ k ] ) */
+        /* Find bits needed in Q( 18 - maxRshifts ) */
+        max_w_bits = silk_max_32( max_w_bits, 32 - silk_CLZ32( w[ k ] ) + corr_rshifts[ k ] - maxRshifts );
+    }
+
+    /* max_abs_d_Q14 = (5 << 15); worst case, i.e. LTP_ORDER * -silk_int16_MIN */
+    silk_assert( max_abs_d_Q14 <= ( 5 << 15 ) );
+
+    /* How many bits is needed for w*d' in Q( 18 - maxRshifts ) in the worst case, of all d_Q14's being equal to max_abs_d_Q14 */
+    extra_shifts = max_w_bits + 32 - silk_CLZ32( max_abs_d_Q14 ) - 14;
+
+    /* Subtract what we got available; bits in output var plus maxRshifts */
+    extra_shifts -= ( 32 - 1 - 2 + maxRshifts ); /* Keep sign bit free as well as 2 bits for accumulation */
+    extra_shifts = silk_max_int( extra_shifts, 0 );
+
+    maxRshifts_wxtra = maxRshifts + extra_shifts;
+
+    temp32 = silk_RSHIFT( 262, maxRshifts + extra_shifts ) + 1; /* 1e-3f in Q( 18 - (maxRshifts + extra_shifts) ) */
+    wd = 0;
+    for( k = 0; k < nb_subfr; k++ ) {
+        /* w has at least 2 bits of headroom so no overflow should happen */
+        temp32 = silk_ADD32( temp32,                     silk_RSHIFT( w[ k ], maxRshifts_wxtra - corr_rshifts[ k ] ) );                      /* Q( 18 - maxRshifts_wxtra ) */
+        wd     = silk_ADD32( wd, silk_LSHIFT( silk_SMULWW( silk_RSHIFT( w[ k ], maxRshifts_wxtra - corr_rshifts[ k ] ), d_Q14[ k ] ), 2 ) ); /* Q( 18 - maxRshifts_wxtra ) */
+    }
+    m_Q12 = silk_DIV32_varQ( wd, temp32, 12 );
+
+    b_Q14_ptr = b_Q14;
+    for( k = 0; k < nb_subfr; k++ ) {
+        /* w_fix[ k ] from Q( 18 - corr_rshifts[ k ] ) to Q( 16 ) */
+        if( 2 - corr_rshifts[k] > 0 ) {
+            temp32 = silk_RSHIFT( w[ k ], 2 - corr_rshifts[ k ] );
+        } else {
+            temp32 = silk_LSHIFT_SAT32( w[ k ], corr_rshifts[ k ] - 2 );
+        }
+
+        g_Q26 = silk_MUL(
+            silk_DIV32(
+                SILK_FIX_CONST( LTP_SMOOTHING, 26 ),
+                silk_RSHIFT( SILK_FIX_CONST( LTP_SMOOTHING, 26 ), 10 ) + temp32 ),                          /* Q10 */
+            silk_LSHIFT_SAT32( silk_SUB_SAT32( (opus_int32)m_Q12, silk_RSHIFT( d_Q14[ k ], 2 ) ), 4 ) );    /* Q16 */
+
+        temp32 = 0;
+        for( i = 0; i < LTP_ORDER; i++ ) {
+            delta_b_Q14[ i ] = silk_max_16( b_Q14_ptr[ i ], 1638 );     /* 1638_Q14 = 0.1_Q0 */
+            temp32 += delta_b_Q14[ i ];                                 /* Q14 */
+        }
+        temp32 = silk_DIV32( g_Q26, temp32 );                           /* Q14 -> Q12 */
+        for( i = 0; i < LTP_ORDER; i++ ) {
+            b_Q14_ptr[ i ] = silk_LIMIT_32( (opus_int32)b_Q14_ptr[ i ] + silk_SMULWB( silk_LSHIFT_SAT32( temp32, 4 ), delta_b_Q14[ i ] ), -16000, 28000 );
+        }
+        b_Q14_ptr += LTP_ORDER;
+    }
+}
+
+void silk_fit_LTP(
+    opus_int32 LTP_coefs_Q16[ LTP_ORDER ],
+    opus_int16 LTP_coefs_Q14[ LTP_ORDER ]
+)
+{
+    opus_int i;
+
+    for( i = 0; i < LTP_ORDER; i++ ) {
+        LTP_coefs_Q14[ i ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( LTP_coefs_Q16[ i ], 2 ) );
+    }
+}