diff --git a/examples/TEMPLATE.yml b/examples/TEMPLATE.yml
index 8c5fdd8e9e0df61640a48cb16147c03ff3accd21..e34d627c4f017c809c1c565ee011e2340e9ce648 100755
--- a/examples/TEMPLATE.yml
+++ b/examples/TEMPLATE.yml
@@ -201,6 +201,9 @@ conditions_to_generate:
           # fs: 48000
           ### Additional commandline options; default = null
           # opts: ["-q", "-no_delay_cmp"]
+      ### Bitstream options
+      # tx:
+          ### For possible arguments see overall bitstream modification
 
   ### IVAS condition ###############################
   c07:
@@ -228,6 +231,9 @@ conditions_to_generate:
           # fs: 48000
           ### Additional commandline options; default = null
           # opts: ["-q", "-no_delay_cmp"]
+      ### Bitstream options
+      # tx:
+          ### For possible arguments see overall bitstream modification
             
   ### EVS condition ################################
   c08:
@@ -249,6 +255,9 @@ conditions_to_generate:
           bin: ~/git/ivas-codec/IVAS_dec
           ### Decoder output sampling rate; default = null (same as input)
           # fs: 48000
+      ### Bitstream options
+      # tx:
+          ### For possible arguments see overall bitstream modification
 
 ################################################
 ### Post-processing
diff --git a/ivas_processing_scripts/processing/chains.py b/ivas_processing_scripts/processing/chains.py
index f830a18b15f55508bf5d49b1f082b29b1cc92855..db5df6ab7d00a9b285d3d896bcdceee661d354fb 100755
--- a/ivas_processing_scripts/processing/chains.py
+++ b/ivas_processing_scripts/processing/chains.py
@@ -239,23 +239,27 @@ def get_processing_chain(
         dec_cfg = cond_cfg["dec"]
 
         # Frame error pattern bitstream modification
-        if "tx" in cond_cfg.keys():
-            tx_cfg = cond_cfg["tx"]
-        elif hasattr(cfg, "tx"):
-            if cfg.tx.get("type", None) == "FER":
+        if "tx" in cond_cfg.keys() or hasattr(cfg, "tx"):
+            # local specification overwrites global one
+            if "tx" in cond_cfg.keys():
+                tx_cfg_tmp = cond_cfg["tx"]
+            else:
+                tx_cfg_tmp = cfg.tx
+
+            if tx_cfg_tmp.get("type", None) == "FER":
                 tx_cfg = {
-                    "type": cfg.tx.get("type", None),
-                    "error_pattern": cfg.tx.get("error_pattern", None),
-                    "error_rate": cfg.tx.get("error_rate", None),
+                    "type": tx_cfg_tmp.get("type", None),
+                    "error_pattern": tx_cfg_tmp.get("error_pattern", None),
+                    "error_rate": tx_cfg_tmp.get("error_rate", None),
                     "master_seed": cfg.master_seed,
-                    "prerun_seed": cfg.tx.get("prerun_seed", 0),
+                    "prerun_seed": tx_cfg_tmp.get("prerun_seed", 0),
                 }
-            elif cfg.tx.get("type", None) == "JBM":
+            elif tx_cfg_tmp.get("type", None) == "JBM":
                 tx_cfg = {
-                    "type": cfg.tx.get("type", None),
-                    "error_pattern": cfg.tx.get("error_pattern", None),
-                    "error_profile": cfg.tx.get("error_profile", None),
-                    "n_frames_per_packet": cfg.tx.get("n_frames_per_packet", 1),
+                    "type": tx_cfg_tmp.get("type", None),
+                    "error_pattern": tx_cfg_tmp.get("error_pattern", None),
+                    "error_profile": tx_cfg_tmp.get("error_profile", None),
+                    "n_frames_per_packet": tx_cfg_tmp.get("n_frames_per_packet", None),
                 }
             else:
                 raise ValueError(
@@ -294,23 +298,27 @@ def get_processing_chain(
         dec_cfg = cond_cfg["dec"]
 
         # Frame error pattern bitstream modification
-        if "tx" in cond_cfg.keys():
-            tx_cfg = cond_cfg["tx"]
-        elif hasattr(cfg, "tx"):
-            if cfg.tx.get("type", None) == "FER":
+        if "tx" in cond_cfg.keys() or hasattr(cfg, "tx"):
+            # local specification overwrites global one
+            if "tx" in cond_cfg.keys():
+                tx_cfg_tmp = cond_cfg["tx"]
+            else:
+                tx_cfg_tmp = cfg.tx
+
+            if tx_cfg_tmp.get("type", None) == "FER":
                 tx_cfg = {
-                    "type": cfg.tx.get("type", None),
-                    "error_pattern": cfg.tx.get("error_pattern", None),
-                    "error_rate": cfg.tx.get("error_rate", None),
+                    "type": tx_cfg_tmp.get("type", None),
+                    "error_pattern": tx_cfg_tmp.get("error_pattern", None),
+                    "error_rate": tx_cfg_tmp.get("error_rate", None),
                     "master_seed": cfg.master_seed,
-                    "prerun_seed": cfg.tx.get("prerun_seed", 0),
+                    "prerun_seed": tx_cfg_tmp.get("prerun_seed", 0),
                 }
-            elif cfg.tx.get("type", None) == "JBM":
+            elif tx_cfg_tmp.get("type", None) == "JBM":
                 tx_cfg = {
-                    "type": cfg.tx.get("type", None),
-                    "error_pattern": cfg.tx.get("error_pattern", None),
-                    "error_profile": cfg.tx.get("error_profile", None),
-                    "n_frames_per_packet": cfg.tx.get("n_frames_per_packet", None),
+                    "type": tx_cfg_tmp.get("type", None),
+                    "error_pattern": tx_cfg_tmp.get("error_pattern", None),
+                    "error_profile": tx_cfg_tmp.get("error_profile", None),
+                    "n_frames_per_packet": tx_cfg_tmp.get("n_frames_per_packet", None),
                 }
             else:
                 raise ValueError(