Update to opus-HEAD-66611f1.

silk/CNG.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.
@@ skipping 16 matching lines @@
 
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
 
 #include "main.h"
 #include "stack_alloc.h"
 
 /* Generates excitation for CNG LPC synthesis */
 static OPUS_INLINE void silk_CNG_exc(
-    opus_int32                       residual_Q10[],     /* O    CNG residual signal Q10                     */
+    opus_int32                       exc_Q10[],          /* O    CNG excitation signal Q10                   */
     opus_int32                       exc_buf_Q14[],      /* I    Random samples buffer Q10                   */
     opus_int32                       Gain_Q16,           /* I    Gain to apply                               */
     opus_int                         length,             /* I    Length                                      */
     opus_int32                       *rand_seed          /* I/O  Seed to random index generator              */
 )
 {
     opus_int32 seed;
     opus_int   i, idx, exc_mask;
 
     exc_mask = CNG_BUF_MASK_MAX;
     while( exc_mask > length ) {
         exc_mask = silk_RSHIFT( exc_mask, 1 );
     }
 
     seed = *rand_seed;
     for( i = 0; i < length; i++ ) {
         seed = silk_RAND( seed );
         idx = (opus_int)( silk_RSHIFT( seed, 24 ) & exc_mask );
         silk_assert( idx >= 0 );
         silk_assert( idx <= CNG_BUF_MASK_MAX );
-        residual_Q10[ i ] = (opus_int16)silk_SAT16( silk_SMULWW( exc_buf_Q14[ idx ], Gain_Q16 >> 4 ) );
+        exc_Q10[ i ] = (opus_int16)silk_SAT16( silk_SMULWW( exc_buf_Q14[ idx ], Gain_Q16 >> 4 ) );
     }
     *rand_seed = seed;
 }
 
 void silk_CNG_Reset(
     silk_decoder_state          *psDec                          /* I/O  Decoder state                               */
 )
 {
     opus_int i, NLSF_step_Q15, NLSF_acc_Q15;
 
     NLSF_step_Q15 = silk_DIV32_16( silk_int16_MAX, psDec->LPC_order + 1 );
     NLSF_acc_Q15 = 0;
     for( i = 0; i < psDec->LPC_order; i++ ) {
         NLSF_acc_Q15 += NLSF_step_Q15;
         psDec->sCNG.CNG_smth_NLSF_Q15[ i ] = NLSF_acc_Q15;
     }
     psDec->sCNG.CNG_smth_Gain_Q16 = 0;
     psDec->sCNG.rand_seed = 3176576;
 }
 
 /* Updates CNG estimate, and applies the CNG when packet was lost   */
 void silk_CNG(
     silk_decoder_state          *psDec,                         /* I/O  Decoder state                               */
     silk_decoder_control        *psDecCtrl,                     /* I/O  Decoder control                             */
     opus_int16                  frame[],                        /* I/O  Signal                                      */
     opus_int                    length                          /* I    Length of residual                          */
 )
 {
     opus_int   i, subfr;
-    opus_int32 sum_Q6, max_Gain_Q16;
+    opus_int32 sum_Q6, max_Gain_Q16, gain_Q16;
     opus_int16 A_Q12[ MAX_LPC_ORDER ];
     silk_CNG_struct *psCNG = &psDec->sCNG;
     SAVE_STACK;
 
     if( psDec->fs_kHz != psCNG->fs_kHz ) {
         /* Reset state */
         silk_CNG_Reset( psDec );
 
         psCNG->fs_kHz = psDec->fs_kHz;
     }
@@ skipping 19 matching lines @@
 
         /* Smooth gains */
         for( i = 0; i < psDec->nb_subfr; i++ ) {
             psCNG->CNG_smth_Gain_Q16 += silk_SMULWB( psDecCtrl->Gains_Q16[ i ] - psCNG->CNG_smth_Gain_Q16, CNG_GAIN_SMTH_Q16 );
         }
     }
 
     /* Add CNG when packet is lost or during DTX */
     if( psDec->lossCnt ) {
         VARDECL( opus_int32, CNG_sig_Q10 );
-
         ALLOC( CNG_sig_Q10, length + MAX_LPC_ORDER, opus_int32 );
 
         /* Generate CNG excitation */
-        silk_CNG_exc( CNG_sig_Q10 + MAX_LPC_ORDER, psCNG->CNG_exc_buf_Q14, psCNG->CNG_smth_Gain_Q16, length, &psCNG->rand_seed );
+        gain_Q16 = silk_SMULWW( psDec->sPLC.randScale_Q14, psDec->sPLC.prevGain_Q16[1] );
+        if( gain_Q16 >= (1 << 21) || psCNG->CNG_smth_Gain_Q16 > (1 << 23) ) {
+            gain_Q16 = silk_SMULTT( gain_Q16, gain_Q16 );
+            gain_Q16 = silk_SUB_LSHIFT32(silk_SMULTT( psCNG->CNG_smth_Gain_Q16, psCNG->CNG_smth_Gain_Q16 ), gain_Q16, 5 );
+            gain_Q16 = silk_LSHIFT32( silk_SQRT_APPROX( gain_Q16 ), 16 );
+        } else {
+            gain_Q16 = silk_SMULWW( gain_Q16, gain_Q16 );
+            gain_Q16 = silk_SUB_LSHIFT32(silk_SMULWW( psCNG->CNG_smth_Gain_Q16, psCNG->CNG_smth_Gain_Q16 ), gain_Q16, 5 );
+            gain_Q16 = silk_LSHIFT32( silk_SQRT_APPROX( gain_Q16 ), 8 );
+        }
+        silk_CNG_exc( CNG_sig_Q10 + MAX_LPC_ORDER, psCNG->CNG_exc_buf_Q14, gain_Q16, length, &psCNG->rand_seed );
 
         /* Convert CNG NLSF to filter representation */
         silk_NLSF2A( A_Q12, psCNG->CNG_smth_NLSF_Q15, psDec->LPC_order );
 
         /* Generate CNG signal, by synthesis filtering */
         silk_memcpy( CNG_sig_Q10, psCNG->CNG_synth_state, MAX_LPC_ORDER * sizeof( opus_int32 ) );
         for( i = 0; i < length; i++ ) {
             silk_assert( psDec->LPC_order == 10 || psDec->LPC_order == 16 );
             /* Avoids introducing a bias because silk_SMLAWB() always rounds to -inf */
             sum_Q6 = silk_RSHIFT( psDec->LPC_order, 1 );
@@ skipping 12 matching lines @@
                 sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 12 ], A_Q12[ 11 ] );
                 sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 13 ], A_Q12[ 12 ] );
                 sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 14 ], A_Q12[ 13 ] );
                 sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 15 ], A_Q12[ 14 ] );
                 sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 16 ], A_Q12[ 15 ] );
             }
 
             /* Update states */
             CNG_sig_Q10[ MAX_LPC_ORDER + i ] = silk_ADD_LSHIFT( CNG_sig_Q10[ MAX_LPC_ORDER + i ], sum_Q6, 4 );
 
-            frame[ i ] = silk_ADD_SAT16( frame[ i ], silk_RSHIFT_ROUND( sum_Q6, 6 ) );
+            frame[ i ] = silk_ADD_SAT16( frame[ i ], silk_RSHIFT_ROUND( CNG_sig_Q10[ MAX_LPC_ORDER + i ], 10 ) );
         }
         silk_memcpy( psCNG->CNG_synth_state, &CNG_sig_Q10[ length ], MAX_LPC_ORDER * sizeof( opus_int32 ) );
     } else {
         silk_memset( psCNG->CNG_synth_state, 0, psDec->LPC_order *  sizeof( opus_int32 ) );
     }
     RESTORE_STACK;
 }