From f6fb2f2c9886e42c8cf23974edeb1b9691444447 Mon Sep 17 00:00:00 2001
From: knj <jan.kiene@iis.fraunhofer.de>
Date: Tue, 16 May 2023 17:05:11 +0200
Subject: [PATCH 1/2] add fix for MDCT-Stereo PLC fadeout with TD concealment

---
 lib_com/ivas_cnst.h  |  3 +++
 lib_com/options.h    |  1 +
 lib_dec/er_dec_tcx.c | 21 ++++++++++++++++++++-
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/lib_com/ivas_cnst.h b/lib_com/ivas_cnst.h
index f6369235a6..b5e3964319 100755
--- a/lib_com/ivas_cnst.h
+++ b/lib_com/ivas_cnst.h
@@ -885,6 +885,9 @@ enum fea_names
 #define MDCT_ST_PLC_FADEOUT_MIN_NOISE_NRG       0.001f
 #define MDCT_ST_PLC_FADEOUT_MAX_CONC_FRAME      2 * FRAMES_PER_SEC
 #define MDCT_ST_PLC_FADEOUT_TO_ZERO_LEN         20
+#ifdef FIX_MDCT_ST_PLC_FADEOUT_DELAY
+#define MDCT_ST_PLC_FADEOUT_DELAY_4_LSP_FADE    3
+#endif
 
 typedef enum {
     EQUAL_CORES,
diff --git a/lib_com/options.h b/lib_com/options.h
index f7ee9e9c7c..23d3060986 100644
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -213,6 +213,7 @@
 #define FIX_DTX_428                                     /* FhG: fix for issue 428, crash with DTX and bitrate switching */
 
 #define FIX_STEREO_474                                  /* FhG fix for issue 574, crash with SBA to stereo output at 512 kbps */
+#define FIX_MDCT_ST_PLC_FADEOUT_DELAY
 
 /* ################## End DEVELOPMENT switches ######################### */
 /* clang-format on */
diff --git a/lib_dec/er_dec_tcx.c b/lib_dec/er_dec_tcx.c
index 1ce3bf2035..e29d8e22b9 100644
--- a/lib_dec/er_dec_tcx.c
+++ b/lib_dec/er_dec_tcx.c
@@ -551,20 +551,39 @@ void con_tcx(
     mvr2r( synth - M, buf, M );
     mvr2r( buf, mem_syn, M );
 
-
     if ( A_cng != NULL )
     {
+#ifdef FIX_MDCT_ST_PLC_FADEOUT_DELAY
+        float alpha_delayed;
+
+        alpha_delayed = 1.0f;
+        if (st->nbLostCmpt > MDCT_ST_PLC_FADEOUT_DELAY_4_LSP_FADE)
+        {
+            alpha_delayed = Damping_fact( st->core_ext_mode, st->nbLostCmpt - MDCT_ST_PLC_FADEOUT_DELAY_4_LSP_FADE, st->last_good, st->stab_fac, &( st->lp_gainp ), ACELP_CORE );
+        }
+
+        if ( st->plcBackgroundNoiseUpdated && alpha_delayed != 1.0f )
+#else
         if ( st->plcBackgroundNoiseUpdated && alpha != 1.0f )
+#endif
         {
             float lsp_local[M], lsp_fade[M], alpha_inv;
 
+#ifdef FIX_MDCT_ST_PLC_FADEOUT_DELAY
+            alpha_inv = 1.0f - alpha_delayed;
+#else
             alpha_inv = 1.0f - alpha;
+#endif
 
             a2lsp_stab( A_local, lsp_local, lsp_local );
 
             for ( i = 0; i < M; i++ )
             {
+#ifdef FIX_MDCT_ST_PLC_FADEOUT_DELAY
+                lsp_fade[i] = alpha_delayed * lsp_local[i] + alpha_inv * st->lspold_cng[i];
+#else
                 lsp_fade[i] = alpha * lsp_local[i] + alpha_inv * st->lspold_cng[i];
+#endif
             }
 
             lsp2a_stab( lsp_fade, A_local, M );
-- 
GitLab


From 69c6748c1b28b2a66f791cde1c498b17399490a7 Mon Sep 17 00:00:00 2001
From: knj <jan.kiene@iis.fraunhofer.de>
Date: Tue, 16 May 2023 17:24:45 +0200
Subject: [PATCH 2/2] apply clang format

---
 lib_dec/er_dec_tcx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib_dec/er_dec_tcx.c b/lib_dec/er_dec_tcx.c
index e29d8e22b9..fb797f92c9 100644
--- a/lib_dec/er_dec_tcx.c
+++ b/lib_dec/er_dec_tcx.c
@@ -557,7 +557,7 @@ void con_tcx(
         float alpha_delayed;
 
         alpha_delayed = 1.0f;
-        if (st->nbLostCmpt > MDCT_ST_PLC_FADEOUT_DELAY_4_LSP_FADE)
+        if ( st->nbLostCmpt > MDCT_ST_PLC_FADEOUT_DELAY_4_LSP_FADE )
         {
             alpha_delayed = Damping_fact( st->core_ext_mode, st->nbLostCmpt - MDCT_ST_PLC_FADEOUT_DELAY_4_LSP_FADE, st->last_good, st->stab_fac, &( st->lp_gainp ), ACELP_CORE );
         }
-- 
GitLab