From 604eace3891c889c327584d6c718160b8039a419 Mon Sep 17 00:00:00 2001
From: Sandesh Venkatesh <sandesh.venkatesh@ittiam.com>
Date: Wed, 19 Mar 2025 10:52:37 +0530
Subject: [PATCH] Fix for 3GPP issue 1385: Decoder crash for Stereo at 32 kbps
 FER in ivas_cpe_dec_fx()

Link #1385
---
 lib_dec/ivas_cpe_dec_fx.c              |  8 ++++----
 lib_dec/ivas_stereo_dft_dec_fx.c       | 16 ++++++++--------
 lib_dec/ivas_stereo_switching_dec_fx.c |  2 +-
 3 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/lib_dec/ivas_cpe_dec_fx.c b/lib_dec/ivas_cpe_dec_fx.c
index 8e25e5116..05fec7736 100644
--- a/lib_dec/ivas_cpe_dec_fx.c
+++ b/lib_dec/ivas_cpe_dec_fx.c
@@ -729,8 +729,8 @@ ivas_error ivas_cpe_dec_fx(
             hCPE->hStereoDft->q_res_cod_mem_fx = hCPE->hStereoDft->q_dft;
             move16();
             stereo_dft_unify_dmx_fx( hCPE->hStereoDft, sts[0], DFT_fx, hCPE->input_mem_fx[1], hCPE->hStereoCng->prev_sid_nodata );
-            scale_sig32( hCPE->hStereoDft->res_cod_mem_fx, STEREO_DFT_OVL_8k, sub( Q16, hCPE->hStereoDft->q_res_cod_mem_fx ) ); // Q16
-            hCPE->hStereoDft->q_res_cod_mem_fx = Q16;
+            scale_sig32( hCPE->hStereoDft->res_cod_mem_fx, STEREO_DFT_OVL_8k, sub( Q15, hCPE->hStereoDft->q_res_cod_mem_fx ) ); // Q15
+            hCPE->hStereoDft->q_res_cod_mem_fx = Q15;
             move16();
         }
         ELSE
@@ -754,8 +754,8 @@ ivas_error ivas_cpe_dec_fx(
                 move16();
             }
             stereo_dft_dec_fx( hCPE->hStereoDft, sts[0], DFT_fx, hCPE->input_mem_fx[1], hCPE->hStereoCng, 0, 0, 0, 0, 0, 0, MAX_PARAM_SPATIAL_SUBFRAMES );
-            scale_sig32( hCPE->hStereoDft->res_cod_mem_fx, STEREO_DFT_OVL_8k, sub( Q16, hCPE->hStereoDft->q_res_cod_mem_fx ) ); // Q16
-            hCPE->hStereoDft->q_res_cod_mem_fx = Q16;
+            scale_sig32( hCPE->hStereoDft->res_cod_mem_fx, STEREO_DFT_OVL_8k, sub( Q15, hCPE->hStereoDft->q_res_cod_mem_fx ) ); // Q15
+            hCPE->hStereoDft->q_res_cod_mem_fx = Q15;
             move16();
         }
 
diff --git a/lib_dec/ivas_stereo_dft_dec_fx.c b/lib_dec/ivas_stereo_dft_dec_fx.c
index 3d9e58ad1..9c1b488cb 100644
--- a/lib_dec/ivas_stereo_dft_dec_fx.c
+++ b/lib_dec/ivas_stereo_dft_dec_fx.c
@@ -146,7 +146,7 @@ void stereo_dft_dec_reset_fx(
     set16_fx( hStereoDft->res_cod_mode, hStereoDft->hConfig->res_cod_mode, STEREO_DFT_DEC_DFT_NB );
     hStereoDft->res_cod_band_max = dft_band_res_cod[hStereoDft->hConfig->band_res][hStereoDft->hConfig->res_cod_mode];
     set32_fx( hStereoDft->res_cod_mem_fx, 0, STEREO_DFT_OVL_8k );
-    hStereoDft->q_res_cod_mem_fx = Q16;
+    hStereoDft->q_res_cod_mem_fx = Q15;
     move16();
 
     hStereoDft->res_pred_band_min = s_max( STEREO_DFT_RES_PRED_BAND_MIN, hStereoDft->res_cod_band_max );
@@ -1357,7 +1357,7 @@ void stereo_dft_dec_res_fx(
     IF( EQ_16( hCPE->hStereoDft->res_cod_mode[STEREO_DFT_OFFSET - 1], STEREO_DFT_RES_COD_OFF ) )
     {
         set32_fx( hCPE->hStereoDft->res_cod_mem_fx, 0, STEREO_DFT_OVL_8k );
-        hCPE->hStereoDft->q_res_cod_mem_fx = Q16;
+        hCPE->hStereoDft->q_res_cod_mem_fx = Q15;
         move16();
         set32_fx( hCPE->input_mem_fx[1], 0, NS2SA( 8000, STEREO_DFT32MS_OVL_NS ) );
         set16_fx( hCPE->hStereoDft->hBpf->pst_old_syn_fx, 0, STEREO_DFT_NBPSF_PIT_MAX_8k );
@@ -1370,7 +1370,7 @@ void stereo_dft_dec_res_fx(
 
     scale_sig( win, L_FRAME8k + STEREO_DFT_OVL_8k, -1 );
 
-    Word16 q_shift = sub( hCPE->hStereoDft->q_res_cod_mem_fx, Q16 );
+    Word16 q_shift = sub( hCPE->hStereoDft->q_res_cod_mem_fx, Q15 );
     IF( !prev_bfi )
     {
         /*OLA*/
@@ -1378,9 +1378,9 @@ void stereo_dft_dec_res_fx(
 
         FOR( i = 0; i < STEREO_DFT_OVL_8k; i++ )
         {
-            win[i] = extract_h( L_add( L_shr( hCPE->hStereoDft->res_cod_mem_fx[i], 1 ), L_shl( L_mult( win[i], hCPE->hStereoDft->win_8k_fx[i] ), q_shift ) ) ); /* q_res_cod_mem_fx -17 (q_shift -1)*/
+            win[i] = extract_h( L_add( hCPE->hStereoDft->res_cod_mem_fx[i], L_shl( L_mult( win[i], hCPE->hStereoDft->win_8k_fx[i] ), q_shift ) ) ); /* q_res_cod_mem_fx -17 (q_shift -1)*/
             move16();
-            hCPE->hStereoDft->res_cod_mem_fx[i] = L_shl( L_mult( win[L_FRAME8k + i], hCPE->hStereoDft->win_8k_fx[STEREO_DFT_OVL_8k - 1 - i] ), 1 ); /* -1 +15 +1 +1 */
+            hCPE->hStereoDft->res_cod_mem_fx[i] = L_mult( win[L_FRAME8k + i], hCPE->hStereoDft->win_8k_fx[STEREO_DFT_OVL_8k - 1 - i] ); /* -1 +15 +1 */
             move32();
         }
 
@@ -1396,11 +1396,11 @@ void stereo_dft_dec_res_fx(
         move16();
         FOR( i = 0; i < STEREO_DFT_OVL_8k; i++ )
         {
-            win[i] = extract_h( Madd_32_16( Mpy_32_16_1( L_shr( hCPE->hStereoDft->res_cod_mem_fx[i], 1 ), sub( MAX_16, mult( fac, fac ) ) ),
+            win[i] = extract_h( Madd_32_16( Mpy_32_16_1( hCPE->hStereoDft->res_cod_mem_fx[i], sub( MAX_16, mult( fac, fac ) ) ),
                                             L_shl( L_mult( hCPE->hStereoDft->win_8k_fx[i], win[i] ), q_shift ),
                                             sub( MAX_16, mult( sub( MAX_16, fac ), sub( MAX_16, fac ) ) ) ) ); /* Q(q_shift -1) */
             move16();
-            hCPE->hStereoDft->res_cod_mem_fx[i] = L_shl( L_mult( win[L_FRAME8k + i], hCPE->hStereoDft->win_8k_fx[STEREO_DFT_OVL_8k - 1 - i] ), 1 ); /* Q16 */
+            hCPE->hStereoDft->res_cod_mem_fx[i] = L_mult( win[L_FRAME8k + i], hCPE->hStereoDft->win_8k_fx[STEREO_DFT_OVL_8k - 1 - i] ); /* Q15 */
             move32();
             fac = add( fac, step );
         }
@@ -1411,7 +1411,7 @@ void stereo_dft_dec_res_fx(
         v_shr_16( &win[STEREO_DFT_OVL_8k], negate( q_shift ), &win[STEREO_DFT_OVL_8k], L_FRAME8k );
     }
 
-    hCPE->hStereoDft->q_res_cod_mem_fx = Q16;
+    hCPE->hStereoDft->q_res_cod_mem_fx = Q15;
 
     Copy( win, out_16, L_FRAME8k ); /* Q(q_shift -1 ) */
 
diff --git a/lib_dec/ivas_stereo_switching_dec_fx.c b/lib_dec/ivas_stereo_switching_dec_fx.c
index 6bf2d7a45..6c2ad055c 100644
--- a/lib_dec/ivas_stereo_switching_dec_fx.c
+++ b/lib_dec/ivas_stereo_switching_dec_fx.c
@@ -1841,7 +1841,7 @@ void stereo_switching_dec(
 
         /* reset residual coding / ESF (secondary channel) */
         set32_fx( hCPE->hStereoDft->res_cod_mem_fx, 0, STEREO_DFT_OVL_8k );
-        hCPE->hStereoDft->q_res_cod_mem_fx = Q16;
+        hCPE->hStereoDft->q_res_cod_mem_fx = Q15;
         move16();
 
         set32_fx( hCPE->input_mem_fx[1], 0, NS2SA_FX2( sts[0]->output_Fs, STEREO_DFT32MS_OVL_NS ) );
-- 
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