Makes pitch gain control less aggressive
diff --git a/silk/quant_LTP_gains.c b/silk/quant_LTP_gains.c
index 1eef2dc..fd0870d 100644
--- a/silk/quant_LTP_gains.c
+++ b/silk/quant_LTP_gains.c
@@ -60,6 +60,10 @@
min_rate_dist_Q14 = silk_int32_MAX;
best_sum_log_gain_Q7 = 0;
for( k = 0; k < 3; k++ ) {
+ /* Safety margin for pitch gain control, to take into account factors
+ such as state rescaling/rewhitening. */
+ opus_int32 gain_safety = SILK_FIX_CONST( 0.4, 7 );
+
cl_ptr_Q5 = silk_LTP_gain_BITS_Q5_ptrs[ k ];
cbk_ptr_Q7 = silk_LTP_vq_ptrs_Q7[ k ];
cbk_gain_ptr_Q7 = silk_LTP_vq_gain_ptrs_Q7[ k ];
@@ -73,7 +77,7 @@
sum_log_gain_tmp_Q7 = *sum_log_gain_Q7;
for( j = 0; j < nb_subfr; j++ ) {
max_gain_Q7 = silk_log2lin( ( SILK_FIX_CONST( MAX_SUM_LOG_GAIN_DB / 6.0, 7 ) - sum_log_gain_tmp_Q7 )
- + SILK_FIX_CONST( 7, 7 ) ) - SILK_FIX_CONST( 0.5, 7 );
+ + SILK_FIX_CONST( 7, 7 ) ) - gain_safety;
silk_VQ_WMat_EC(
&temp_idx[ j ], /* O index of best codebook vector */
@@ -90,7 +94,8 @@
);
rate_dist_Q14 = silk_ADD_POS_SAT32( rate_dist_Q14, rate_dist_Q14_subfr );
- sum_log_gain_tmp_Q7 += silk_lin2log( SILK_FIX_CONST( 0.5, 7 ) + gain_Q7 ) - SILK_FIX_CONST( 7, 7 );
+ sum_log_gain_tmp_Q7 = silk_max(0, sum_log_gain_tmp_Q7
+ + silk_lin2log( gain_safety + gain_Q7 ) - SILK_FIX_CONST( 7, 7 ));
b_Q14_ptr += LTP_ORDER;
W_Q18_ptr += LTP_ORDER * LTP_ORDER;
