diff --git a/iamf/cli/BUILD b/iamf/cli/BUILD
index 7f0e469..ab0a0b7 100644
--- a/iamf/cli/BUILD
+++ b/iamf/cli/BUILD
@@ -128,7 +128,6 @@ cc_library(
         "//iamf/obu:audio_frame",
         "//iamf/obu:parameter_data",
         "//iamf/obu:types",
-        "@com_google_absl//absl/container:btree",
         "@com_google_absl//absl/container:flat_hash_map",
         "@com_google_absl//absl/container:flat_hash_set",
         "@com_google_absl//absl/container:node_hash_map",
diff --git a/iamf/cli/demixing_module.h b/iamf/cli/demixing_module.h
index 22baec4..f95f1ef 100644
--- a/iamf/cli/demixing_module.h
+++ b/iamf/cli/demixing_module.h
@@ -18,7 +18,6 @@
 #include <list>
 #include <vector>
 
-#include "absl/container/btree_map.h"
 #include "absl/container/flat_hash_map.h"
 #include "absl/container/node_hash_map.h"
 #include "absl/status/status.h"
@@ -71,13 +70,6 @@ struct LabeledFrame {
 // Mapping from audio element ids to `LabeledFrame`s.
 typedef absl::flat_hash_map<DecodedUleb128, LabeledFrame> IdLabeledFrameMap;
 
-// Mapping from starting timestamps to `LabeledFrame`s.
-typedef absl::btree_map<int32_t, LabeledFrame> TimeLabeledFrameMap;
-
-// Mapping from audio element ids to `TimeLabeledFrameMap`s.
-typedef absl::flat_hash_map<DecodedUleb128, TimeLabeledFrameMap>
-    IdTimeLabeledFrameMap;
-
 typedef absl::Status (*Demixer)(const DownMixingParams&, LabelSamplesMap&);
 
 /*!\brief Manages data and processing to down-mix and demix audio elements.
diff --git a/iamf/cli/encoder_main_lib.cc b/iamf/cli/encoder_main_lib.cc
index 2445317..2a7018f 100644
--- a/iamf/cli/encoder_main_lib.cc
+++ b/iamf/cli/encoder_main_lib.cc
@@ -225,7 +225,6 @@ absl::Status GenerateObus(
   // TODO(b/329375123): Make two while loops that run on two threads: one for
   //                    adding samples and parameter block metadata, and one for
   //                    outputing OBUs.
-  IdTimeLabeledFrameMap id_to_time_to_labeled_frame;
   int data_obus_iteration = 0;  // Just for logging purposes.
   while (iamf_encoder.GeneratingDataObus()) {
     LOG_EVERY_N_SEC(INFO, 5)