From 307b1e39e1611349dcd5a410a8607a088f4a7fe2 Mon Sep 17 00:00:00 2001
From: Tommy Vaillancourt <Tommy.Vaillancourt@usherbrooke.ca>
Date: Tue, 3 Feb 2026 15:30:04 -0500
Subject: [PATCH 1/2] fix proposal for #2407

---
 lib_com/options.h   |  2 +-
 lib_com/residu_fx.c | 18 ++++++++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/lib_com/options.h b/lib_com/options.h
index 0ea316a82..ec9d44855 100644
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -122,7 +122,7 @@
 #define FIX_1283_STEREO_DFT_COLLAPSE                    /* FhG: float issue 1283: fix for critical issue with DFT stereo core coder */
 #define FIX_2379_REMOVE_previoussynth_fx_32             /* VA: basop issue 2379: remove duplicated buffer st->previoussynth_fx_32[] */
 #define FIX_2396_CONSTANT_STRIDE_IN_TC_BUFFER           /* FhG/VA: basop issue 2396: keep TC channel pointers in one constant place during decoding and rendering */
-
+#define FIX_2407_FIX_RESIDU_IVAS                        /* VA: basop 2407, Implementation issue in residu_ivas + unnecessary complexity */
 /* ##################### End NON-BE switches ########################### */
 
 /* ################## End MAINTENANCE switches ######################### */
diff --git a/lib_com/residu_fx.c b/lib_com/residu_fx.c
index 60c0c3356..b281f11a2 100644
--- a/lib_com/residu_fx.c
+++ b/lib_com/residu_fx.c
@@ -24,6 +24,7 @@ void residu_ivas_fx(
     const Word16 l   /* i  : size of filtering                */
 )
 {
+#ifndef FIX_2407_FIX_RESIDU_IVAS
     Word32 s;
     Word16 i, j;
 
@@ -38,7 +39,24 @@ void residu_ivas_fx(
         y[i] = s;
         move32();
     }
+#else
+    Word64 s64;
+    Word16 i, j, scaling;
+
+    scaling = sub( Q15, a_exp );
+    FOR( i = 0; i < l; i++ )
+    {
+        s64 = W_mult_32_16( x[i], a[0] );
+        move32();
+        FOR( j = 1; j <= m; j++ )
+        {
+            s64 = W_mac_32_16( s64, x[i - j], a[j] );
+        }
+        y[i] = W_shl_sat_l( s64, scaling );
+        move32();
+    }
 
+#endif
     return;
 }
 
-- 
GitLab


From f8c617e78c045797459b209c9e2020910291e9d9 Mon Sep 17 00:00:00 2001
From: Tommy Vaillancourt <Tommy.Vaillancourt@usherbrooke.ca>
Date: Wed, 4 Feb 2026 08:43:20 -0500
Subject: [PATCH 2/2] remove 1 not necessary move()

---
 lib_com/residu_fx.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/lib_com/residu_fx.c b/lib_com/residu_fx.c
index b281f11a2..7008b4cf0 100644
--- a/lib_com/residu_fx.c
+++ b/lib_com/residu_fx.c
@@ -47,7 +47,6 @@ void residu_ivas_fx(
     FOR( i = 0; i < l; i++ )
     {
         s64 = W_mult_32_16( x[i], a[0] );
-        move32();
         FOR( j = 1; j <= m; j++ )
         {
             s64 = W_mac_32_16( s64, x[i - j], a[j] );
-- 
GitLab