diff --git a/iamf/cli/BUILD b/iamf/cli/BUILD
index c9f849d..cc781d7 100644
--- a/iamf/cli/BUILD
+++ b/iamf/cli/BUILD
@@ -392,7 +392,6 @@ cc_library(
         "@com_google_absl//absl/container:flat_hash_map",
         "@com_google_absl//absl/log",
         "@com_google_absl//absl/status",
-        "@com_google_absl//absl/strings",
     ],
 )
 
diff --git a/iamf/cli/adm_to_user_metadata/iamf/BUILD b/iamf/cli/adm_to_user_metadata/iamf/BUILD
index 8dbef08..7c1833d 100644
--- a/iamf/cli/adm_to_user_metadata/iamf/BUILD
+++ b/iamf/cli/adm_to_user_metadata/iamf/BUILD
@@ -11,6 +11,7 @@ cc_library(
         "//iamf/cli/proto:audio_element_cc_proto",
         "//iamf/cli/proto:ia_sequence_header_cc_proto",
         "//iamf/cli/proto:user_metadata_cc_proto",
+        "//iamf/common:obu_util",
         "@com_google_absl//absl/base:no_destructor",
         "@com_google_absl//absl/container:flat_hash_map",
         "@com_google_absl//absl/status",
@@ -29,6 +30,7 @@ cc_library(
         ":iamf_input_layout",
         "//iamf/cli/proto:audio_frame_cc_proto",
         "//iamf/cli/proto:user_metadata_cc_proto",
+        "//iamf/common:obu_util",
         "@com_google_absl//absl/base:no_destructor",
         "@com_google_absl//absl/container:flat_hash_map",
         "@com_google_absl//absl/status",
@@ -88,9 +90,9 @@ cc_library(
     srcs = ["iamf_input_layout.cc"],
     hdrs = ["iamf_input_layout.h"],
     deps = [
+        "//iamf/common:obu_util",
         "@com_google_absl//absl/base:no_destructor",
         "@com_google_absl//absl/container:flat_hash_map",
-        "@com_google_absl//absl/status",
         "@com_google_absl//absl/status:statusor",
         "@com_google_absl//absl/strings",
     ],
diff --git a/iamf/cli/adm_to_user_metadata/iamf/audio_element_handler.cc b/iamf/cli/adm_to_user_metadata/iamf/audio_element_handler.cc
index 5ed943a..619d466 100644
--- a/iamf/cli/adm_to_user_metadata/iamf/audio_element_handler.cc
+++ b/iamf/cli/adm_to_user_metadata/iamf/audio_element_handler.cc
@@ -22,6 +22,7 @@
 #include "iamf/cli/adm_to_user_metadata/iamf/iamf_input_layout.h"
 #include "iamf/cli/proto/audio_element.pb.h"
 #include "iamf/cli/proto/user_metadata.pb.h"
+#include "iamf/common/obu_util.h"
 
 namespace iamf_tools {
 namespace adm_to_user_metadata {
@@ -49,12 +50,8 @@ absl::StatusOr<int32_t> LookupNumSubstreamsFromInputLayout(
           {kAmbisonicsOrder3, 16},
       });
 
-  auto it = kInputLayoutToNumSubstreams->find(input_layout);
-  if (it == kInputLayoutToNumSubstreams->end()) {
-    return absl::NotFoundError(absl::StrCat(
-        "Num substreams not found for input_layout= ", input_layout));
-  }
-  return it->second;
+  return LookupInMap(*kInputLayoutToNumSubstreams, input_layout,
+                     "Number of channels for `IamfInputLayout`");
 }
 
 absl::StatusOr<int32_t> LookupCoupledSubstreamCountFromInputLayout(
@@ -74,12 +71,8 @@ absl::StatusOr<int32_t> LookupCoupledSubstreamCountFromInputLayout(
           {kBinaural, 1},
       });
 
-  auto it = kInputLayoutToCoupledSubstreamCount->find(input_layout);
-  if (it == kInputLayoutToCoupledSubstreamCount->end()) {
-    return absl::NotFoundError(absl::StrCat(
-        "Coupled substream count not found for input_layout= ", input_layout));
-  }
-  return it->second;
+  return LookupInMap(*kInputLayoutToCoupledSubstreamCount, input_layout,
+                     "Coupled substream count for `IamfInputLayout`");
 }
 
 absl::StatusOr<iamf_tools_cli_proto::LoudspeakerLayout>
@@ -102,12 +95,8 @@ LookupLoudspeakerLayoutFromInputLayout(IamfInputLayout input_layout) {
           {kBinaural, LOUDSPEAKER_LAYOUT_BINAURAL},
       });
 
-  auto it = KInputLayoutToLoudspeakerLayout->find(input_layout);
-  if (it == KInputLayoutToLoudspeakerLayout->end()) {
-    return absl::NotFoundError(absl::StrCat(
-        "Loudspeaker layout not found for input_layout= ", input_layout));
-  }
-  return it->second;
+  return LookupInMap(*KInputLayoutToLoudspeakerLayout, input_layout,
+                     "Proto `LoudspeakerLayout` for `IamfInputLayout`");
 }
 
 absl::StatusOr<iamf_tools_cli_proto::AudioElementType>
@@ -133,12 +122,8 @@ LookupAudioElementTypeFromInputLayout(IamfInputLayout input_layout) {
           {kAmbisonicsOrder3, AUDIO_ELEMENT_SCENE_BASED},
       });
 
-  auto it = KInputLayoutToAudioElementType->find(input_layout);
-  if (it == KInputLayoutToAudioElementType->end()) {
-    return absl::NotFoundError(absl::StrCat(
-        "Loudspeaker layout not found for input_layout= ", input_layout));
-  }
-  return it->second;
+  return LookupInMap(*KInputLayoutToAudioElementType, input_layout,
+                     "Proto `AudioElementType` for `IamfInputLayout`");
 }
 
 absl::Status PopulateChannelBasedAudioElementMetadata(
diff --git a/iamf/cli/adm_to_user_metadata/iamf/audio_frame_handler.cc b/iamf/cli/adm_to_user_metadata/iamf/audio_frame_handler.cc
index 7fc8466..f0b443b 100644
--- a/iamf/cli/adm_to_user_metadata/iamf/audio_frame_handler.cc
+++ b/iamf/cli/adm_to_user_metadata/iamf/audio_frame_handler.cc
@@ -25,6 +25,7 @@
 #include "iamf/cli/adm_to_user_metadata/iamf/iamf_input_layout.h"
 #include "iamf/cli/proto/audio_frame.pb.h"
 #include "iamf/cli/proto/user_metadata.pb.h"
+#include "iamf/common/obu_util.h"
 
 namespace iamf_tools {
 namespace adm_to_user_metadata {
@@ -59,12 +60,8 @@ absl::StatusOr<std::vector<std::string>> LookupLabelsFromInputLayout(
             "A11", "A12", "A13", "A14", "A15"}},
       });
 
-  auto it = kInputLayoutToLabels->find(input_layout);
-  if (it == kInputLayoutToLabels->end()) {
-    return absl::NotFoundError(
-        absl::StrCat("Labels not found for input_layout= ", input_layout));
-  }
-  return it->second;
+  return LookupInMap(*kInputLayoutToLabels, input_layout,
+                     "String-based channels labels for `IamfInputLayout`");
 }
 
 }  // namespace
diff --git a/iamf/cli/adm_to_user_metadata/iamf/iamf_input_layout.cc b/iamf/cli/adm_to_user_metadata/iamf/iamf_input_layout.cc
index 0ece10d..a8d73e3 100644
--- a/iamf/cli/adm_to_user_metadata/iamf/iamf_input_layout.cc
+++ b/iamf/cli/adm_to_user_metadata/iamf/iamf_input_layout.cc
@@ -12,14 +12,11 @@
 
 #include "iamf/cli/adm_to_user_metadata/iamf/iamf_input_layout.h"
 
-#include <string>
-
 #include "absl/base/no_destructor.h"
 #include "absl/container/flat_hash_map.h"
-#include "absl/status/status.h"
 #include "absl/status/statusor.h"
-#include "absl/strings/str_cat.h"
 #include "absl/strings/string_view.h"
+#include "iamf/common/obu_util.h"
 
 namespace iamf_tools {
 namespace adm_to_user_metadata {
@@ -30,7 +27,7 @@ absl::StatusOr<IamfInputLayout> LookupInputLayoutFromAudioPackFormatId(
   // loudspeaker layout in IAMF.
   using enum IamfInputLayout;
   static const absl::NoDestructor<
-      absl::flat_hash_map<std::string, IamfInputLayout>>
+      absl::flat_hash_map<absl::string_view, IamfInputLayout>>
       kAudioPackFormatIdToInputLayout({
           {"AP_00010001", IamfInputLayout::kMono},
           {"AP_00010002", IamfInputLayout::kStereo},
@@ -45,13 +42,8 @@ absl::StatusOr<IamfInputLayout> LookupInputLayoutFromAudioPackFormatId(
           {"AP_00040003", IamfInputLayout::kAmbisonicsOrder3},
       });
 
-  auto it = kAudioPackFormatIdToInputLayout->find(audio_pack_format_id);
-  if (it == kAudioPackFormatIdToInputLayout->end()) {
-    return absl::NotFoundError(
-        absl::StrCat("Input layout not found for audio_pack_format_id= ",
-                     audio_pack_format_id));
-  }
-  return it->second;
+  return LookupInMap(*kAudioPackFormatIdToInputLayout, audio_pack_format_id,
+                     "`IamfInputLayout` for `audio_pack_format_id`");
 }
 
 }  // namespace adm_to_user_metadata
diff --git a/iamf/cli/adm_to_user_metadata/iamf/mix_presentation_handler.cc b/iamf/cli/adm_to_user_metadata/iamf/mix_presentation_handler.cc
index f13d385..9dc4d20 100644
--- a/iamf/cli/adm_to_user_metadata/iamf/mix_presentation_handler.cc
+++ b/iamf/cli/adm_to_user_metadata/iamf/mix_presentation_handler.cc
@@ -53,11 +53,8 @@ LookupSoundSystemFromInputLayout(IamfInputLayout layout) {
           {k7_1_4, SOUND_SYSTEM_J_4_7_0},
       });
 
-  auto it = kInputLayoutToSoundSystem->find(layout);
-  if (it == kInputLayoutToSoundSystem->end()) {
-    return absl::NotFoundError("Sound system not found for input_layout");
-  }
-  return it->second;
+  return LookupInMap(*kInputLayoutToSoundSystem, layout,
+                     "`SoundSystem` for `IamfInputLayout`");
 }
 
 absl::Status CopyLoudness(const LoudnessMetadata& loudness_metadata,
diff --git a/iamf/cli/channel_label.cc b/iamf/cli/channel_label.cc
index 4223147..2585b02 100644
--- a/iamf/cli/channel_label.cc
+++ b/iamf/cli/channel_label.cc
@@ -13,7 +13,6 @@
 
 #include <optional>
 #include <string>
-#include <utility>
 #include <vector>
 
 #include "absl/base/no_destructor.h"
@@ -60,12 +59,8 @@ LookupEarChannelOrderFromNonExpandedLoudspeakerLayout(
           {kLayoutBinaural, {kL2, kR2}},
       });
 
-  auto it = kSoundSystemToLoudspeakerLayout->find(loudspeaker_layout);
-  if (it == kSoundSystemToLoudspeakerLayout->end()) {
-    return absl::InvalidArgumentError(absl::StrCat(
-        "Channel order not found for layout= ", loudspeaker_layout));
-  }
-  return it->second;
+  return LookupInMap(*kSoundSystemToLoudspeakerLayout, loudspeaker_layout,
+                     "`ChannelLabel::Label` for `LoudspeakerLayout`");
 }
 
 void SetLabelsToOmittedExceptFor(
@@ -180,7 +175,7 @@ absl::StatusOr<ChannelLabel::Label> ChannelLabel::StringToLabel(
     absl::string_view label) {
   using enum ChannelLabel::Label;
   static const absl::NoDestructor<
-      absl::flat_hash_map<std::string, ChannelLabel::Label>>
+      absl::flat_hash_map<absl::string_view, ChannelLabel::Label>>
       kStringToChannelLabel({
           {"Omitted", kOmitted},
           {"M", kMono},
@@ -265,12 +260,8 @@ absl::StatusOr<ChannelLabel::Label> ChannelLabel::StringToLabel(
           {"A24", kA24},
       });
 
-  auto it = kStringToChannelLabel->find(label);
-  if (it == kStringToChannelLabel->end()) {
-    return absl::InvalidArgumentError(
-        absl::StrCat("Unknown string-based label= ", label));
-  }
-  return it->second;
+  return LookupInMap(*kStringToChannelLabel, label,
+                     "`Channel::Label` for string-based label");
 }
 
 absl::StatusOr<ChannelLabel::Label> ChannelLabel::ProtoToLabel(
@@ -607,13 +598,8 @@ absl::StatusOr<ChannelLabel::Label> ChannelLabel::GetDemixedLabel(
                                    {kR7, kDemixedR7},
                                    {kLrs7, kDemixedLrs7},
                                    {kRrs7, kDemixedRrs7}});
-
-  auto it = kChannelLabelToDemixedLabel->find(label);
-  if (it == kChannelLabelToDemixedLabel->end()) {
-    return absl::InvalidArgumentError(absl::StrCat(
-        "Demixed label is not known or allowed for label= ", label));
-  }
-  return it->second;
+  return LookupInMap(*kChannelLabelToDemixedLabel, label,
+                     "Demixed label for `ChannelLabel::Label`");
 }
 
 absl::StatusOr<std::vector<ChannelLabel::Label>>
diff --git a/iamf/cli/obu_to_proto/BUILD b/iamf/cli/obu_to_proto/BUILD
index 44709af..335d234 100644
--- a/iamf/cli/obu_to_proto/BUILD
+++ b/iamf/cli/obu_to_proto/BUILD
@@ -21,6 +21,5 @@ cc_library(
         "@com_google_absl//absl/log:check",
         "@com_google_absl//absl/status",
         "@com_google_absl//absl/status:statusor",
-        "@com_google_absl//absl/strings",
     ],
 )
diff --git a/iamf/cli/obu_to_proto/parameter_block_metadata_generator.cc b/iamf/cli/obu_to_proto/parameter_block_metadata_generator.cc
index 8ab9727..282d65f 100644
--- a/iamf/cli/obu_to_proto/parameter_block_metadata_generator.cc
+++ b/iamf/cli/obu_to_proto/parameter_block_metadata_generator.cc
@@ -20,7 +20,6 @@
 #include "absl/log/log.h"
 #include "absl/status/status.h"
 #include "absl/status/statusor.h"
-#include "absl/strings/str_cat.h"
 #include "iamf/cli/proto/parameter_block.pb.h"
 #include "iamf/cli/proto/parameter_data.pb.h"
 #include "iamf/common/macros.h"
@@ -113,14 +112,9 @@ absl::Status CopyDMixPMode(DemixingInfoParameterData::DMixPMode obu_dmixp_mode,
           {kDMixPMode3_n, DMIXP_MODE_3_N},
           {kDMixPModeReserved2, DMIXP_MODE_RESERVED_B},
       });
-  if (!LookupInMap(*kObuDmixPModeToMetadataDMixPMode, obu_dmixp_mode,
-                   dmixp_mode)
-           .ok()) {
-    return absl::InvalidArgumentError(
-        absl::StrCat("Unknown dmixp_mode = ", obu_dmixp_mode));
-  }
 
-  return absl::OkStatus();
+  return CopyFromMap(*kObuDmixPModeToMetadataDMixPMode, obu_dmixp_mode,
+                     "Proto version of internal `DMixPMode`", dmixp_mode);
 }
 
 // Gets the proto representation of the input `mix_gain_parameter_data`.
diff --git a/iamf/cli/proto_to_obu/arbitrary_obu_generator.cc b/iamf/cli/proto_to_obu/arbitrary_obu_generator.cc
index e96bbcf..fdf4b71 100644
--- a/iamf/cli/proto_to_obu/arbitrary_obu_generator.cc
+++ b/iamf/cli/proto_to_obu/arbitrary_obu_generator.cc
@@ -73,13 +73,9 @@ absl::Status CopyArbitraryObuType(
           {OBU_IA_SEQUENCE_HEADER, kObuIaSequenceHeader},
       });
 
-  if (!LookupInMap(*kArbitraryObuTypeToObuType, arbitrary_obu_type,
-                   output_obu_type)
-           .ok()) {
-    return absl::InvalidArgumentError(
-        absl::StrCat("Unknown arbitrary_obu_type= ", arbitrary_obu_type));
-  }
-  return absl::OkStatus();
+  return CopyFromMap(*kArbitraryObuTypeToObuType, arbitrary_obu_type,
+                     "Internal version of proto `ArbitraryObuType`",
+                     output_obu_type);
 }
 }  // namespace
 
diff --git a/iamf/cli/proto_to_obu/audio_element_generator.cc b/iamf/cli/proto_to_obu/audio_element_generator.cc
index 0f7288c..3fafa66 100644
--- a/iamf/cli/proto_to_obu/audio_element_generator.cc
+++ b/iamf/cli/proto_to_obu/audio_element_generator.cc
@@ -721,16 +721,10 @@ absl::Status CopyLoudspeakerLayout(
           {LOUDSPEAKER_LAYOUT_EXPANDED, kLayoutExpanded},
       });
 
-  if (!LookupInMap(*kInputLoudspeakerLayoutToOutputLoudspeakerLayout,
-                   input_channel_audio_layer_config.loudspeaker_layout(),
-                   output_loudspeaker_layout)
-           .ok()) {
-    return InvalidArgumentError(
-        StrCat("Unknown loudspeaker_layout= ",
-               input_channel_audio_layer_config.loudspeaker_layout()));
-  }
-
-  return absl::OkStatus();
+  return CopyFromMap(*kInputLoudspeakerLayoutToOutputLoudspeakerLayout,
+                     input_channel_audio_layer_config.loudspeaker_layout(),
+                     "Internal version of proto `LoudspeakerLayout`= ",
+                     output_loudspeaker_layout);
 }
 
 // Copies the `ExpandedLoudspeakerLayout` based on the input data.
@@ -760,15 +754,10 @@ absl::Status CopyExpandedLoudspeakerLayout(
           {EXPANDED_LOUDSPEAKER_LAYOUT_TOP_6_CH, kExpandedLayoutTop6Ch},
       });
 
-  if (!LookupInMap(*kInputLoudspeakerLayoutToOutputLoudspeakerLayout,
-                   input_expanded_loudspeaker_layout,
-                   output_expanded_loudspeaker_layout)
-           .ok()) {
-    return InvalidArgumentError(StrCat("Unknown expanded_loudspeaker_layout= ",
-                                       input_expanded_loudspeaker_layout));
-  }
-
-  return absl::OkStatus();
+  return CopyFromMap(*kInputLoudspeakerLayoutToOutputLoudspeakerLayout,
+                     input_expanded_loudspeaker_layout,
+                     "Internal version of proto `ExpandedLoudspeakerLayout`= ",
+                     output_expanded_loudspeaker_layout);
 }
 
 // Copies the `LoudspeakerLayout` and `ExpandedLoudspeakerLayout` based on the
diff --git a/iamf/cli/proto_to_obu/codec_config_generator.cc b/iamf/cli/proto_to_obu/codec_config_generator.cc
index ca80b22..164dde7 100644
--- a/iamf/cli/proto_to_obu/codec_config_generator.cc
+++ b/iamf/cli/proto_to_obu/codec_config_generator.cc
@@ -66,13 +66,9 @@ absl::Status CopyCodecId(
           {CODEC_ID_LPCM, kCodecIdLpcm},
       });
 
-  if (!LookupInMap(*kInputCodecIdToOutputCodecId, input_codec_config.codec_id(),
-                   output_codec_id)
-           .ok()) {
-    return absl::InvalidArgumentError(absl::StrCat(
-        "Unknown codec with codec_id= ", input_codec_config.codec_id()));
-  }
-  return absl::OkStatus();
+  return CopyFromMap(*kInputCodecIdToOutputCodecId,
+                     input_codec_config.codec_id(),
+                     "Internal version of proto `CodecId`= ", output_codec_id);
 }
 
 absl::Status CopyFlacBlockType(
@@ -91,13 +87,9 @@ absl::Status CopyFlacBlockType(
            {FLAC_BLOCK_TYPE_CUESHEET, kFlacCuesheet},
            {FLAC_BLOCK_TYPE_PICTURE, kFlacPicture}});
 
-  if (!LookupInMap(*kInputFlacBlockTypeToOutputFlacBlockType,
-                   input_flac_block_type, output_flac_block_type)
-           .ok()) {
-    return absl::InvalidArgumentError(
-        absl::StrCat("Unknown input_flac_block_type= ", input_flac_block_type));
-  }
-  return absl::OkStatus();
+  return CopyFromMap(
+      *kInputFlacBlockTypeToOutputFlacBlockType, input_flac_block_type,
+      "Internal version of proto `FlacBlockType`", output_flac_block_type);
 }
 
 absl::Status CopySampleFrequencyIndex(
@@ -131,14 +123,10 @@ absl::Status CopySampleFrequencyIndex(
            kSampleFrequencyIndexEscapeValue},
       });
 
-  if (!LookupInMap(*kInputSampleFrequencyIndexToOutputSampleFrequencyIndex,
-                   input_sample_frequency_index, output_sample_frequency_index)
-           .ok()) {
-    return absl::InvalidArgumentError(
-        absl::StrCat("Unknown input_sample_frequency_index= ",
-                     input_sample_frequency_index));
-  }
-  return absl::OkStatus();
+  return CopyFromMap(*kInputSampleFrequencyIndexToOutputSampleFrequencyIndex,
+                     input_sample_frequency_index,
+                     "Internal version of proto `SampleFrequencyIndex`",
+                     output_sample_frequency_index);
 }
 
 absl::Status GenerateLpcmDecoderConfig(
diff --git a/iamf/cli/proto_to_obu/mix_presentation_generator.cc b/iamf/cli/proto_to_obu/mix_presentation_generator.cc
index 7e4ba2d..b9702b0 100644
--- a/iamf/cli/proto_to_obu/mix_presentation_generator.cc
+++ b/iamf/cli/proto_to_obu/mix_presentation_generator.cc
@@ -338,13 +338,9 @@ absl::Status MixPresentationGenerator::CopySoundSystem(
           {SOUND_SYSTEM_13_6_9_0, kSoundSystem13_6_9_0},
       });
 
-  if (!LookupInMap(*kInputSoundSystemToOutputSoundSystem, input_sound_system,
-                   output_sound_system)
-           .ok()) {
-    return absl::InvalidArgumentError(
-        absl::StrCat("Unknown input_sound_system= ", input_sound_system));
-  }
-  return absl::OkStatus();
+  return CopyFromMap(
+      *kInputSoundSystemToOutputSoundSystem, input_sound_system,
+      "Internal version of proto `SoundSystem`= ", output_sound_system);
 }
 
 absl::Status MixPresentationGenerator::CopyInfoType(
@@ -384,14 +380,12 @@ absl::Status MixPresentationGenerator::CopyInfoType(
   uint8_t accumulated_info_type_bitmask = 0;
   for (int i = 0; i < input_loudness_info.info_type_bit_masks_size(); ++i) {
     LoudnessInfo::InfoTypeBitmask user_output_bit_mask;
-    if (!LookupInMap(
-             *kInputLoudnessInfoTypeBitMaskToOutputLoudnessInfoTypeBitMask,
-             input_loudness_info.info_type_bit_masks(i), user_output_bit_mask)
-             .ok()) {
-      return absl::InvalidArgumentError(
-          absl::StrCat("Unknown info_type_bit_masks(", i,
-                       ")= ", input_loudness_info.info_type_bit_masks(i)));
-    }
+    RETURN_IF_NOT_OK(CopyFromMap(
+        *kInputLoudnessInfoTypeBitMaskToOutputLoudnessInfoTypeBitMask,
+        input_loudness_info.info_type_bit_masks(i),
+        absl::StrCat("Internal version of proto `LoudnessInfoTypeBitMask(", i,
+                     ")= "),
+        user_output_bit_mask));
 
     // Track the accumulated bit mask.
     accumulated_info_type_bitmask |= static_cast<uint8_t>(user_output_bit_mask);
diff --git a/iamf/cli/proto_to_obu/tests/arbitrary_obu_generator_test.cc b/iamf/cli/proto_to_obu/tests/arbitrary_obu_generator_test.cc
index eddfa06..b48619d 100644
--- a/iamf/cli/proto_to_obu/tests/arbitrary_obu_generator_test.cc
+++ b/iamf/cli/proto_to_obu/tests/arbitrary_obu_generator_test.cc
@@ -216,20 +216,18 @@ class ArbitraryObuGeneratorTest : public testing::Test {
  public:
   ArbitraryObuGeneratorTest() {}
 
-  void InitAndTestGenerate() {
+  void InitAndTestGenerateExpectOk() {
     // Generate the OBUs.
     std::list<ArbitraryObu> output_obus;
     ArbitraryObuGenerator generator(arbitrary_obu_metadata_);
-    EXPECT_EQ(generator.Generate(output_obus).code(),
-              expected_generate_status_code_);
+    EXPECT_THAT(generator.Generate(output_obus), IsOk());
+
     EXPECT_EQ(output_obus, expected_obus_);
   }
 
  protected:
   ArbitraryObuMetadatas arbitrary_obu_metadata_;
 
-  absl::StatusCode expected_generate_status_code_ = absl::StatusCode::kOk;
-
   std::list<ArbitraryObu> expected_obus_;
 };
 
@@ -250,7 +248,7 @@ TEST_F(ArbitraryObuGeneratorTest, ReservedObu) {
   expected_obus_.emplace_back(kObuIaReserved24, ObuHeader(),
                               std::vector<uint8_t>({'a', 'b', 'c'}),
                               ArbitraryObu::kInsertionHookBeforeDescriptors);
-  InitAndTestGenerate();
+  InitAndTestGenerateExpectOk();
 }
 
 TEST_F(ArbitraryObuGeneratorTest, ObuWithExtensionHeader) {
@@ -276,7 +274,7 @@ TEST_F(ArbitraryObuGeneratorTest, ObuWithExtensionHeader) {
                 .extension_header_bytes = {'e', 'x', 't', 'r', 'a'}},
       std::vector<uint8_t>({'i', 'a', 'm', 'f', '\0', '\0'}),
       ArbitraryObu::kInsertionHookAfterDescriptors);
-  InitAndTestGenerate();
+  InitAndTestGenerateExpectOk();
 }
 
 TEST_F(ArbitraryObuGeneratorTest, InvalidObuType) {
@@ -292,9 +290,10 @@ TEST_F(ArbitraryObuGeneratorTest, InvalidObuType) {
         payload: ""
       )pb",
       arbitrary_obu_metadata_.Add()));
-  expected_generate_status_code_ = absl::StatusCode::kInvalidArgument;
+  std::list<ArbitraryObu> output_obus;
+  ArbitraryObuGenerator generator(arbitrary_obu_metadata_);
 
-  InitAndTestGenerate();
+  EXPECT_FALSE(generator.Generate(output_obus).ok());
 }
 
 }  // namespace
diff --git a/iamf/cli/recon_gain_generator.cc b/iamf/cli/recon_gain_generator.cc
index fdd69e8..9a750a3 100644
--- a/iamf/cli/recon_gain_generator.cc
+++ b/iamf/cli/recon_gain_generator.cc
@@ -18,7 +18,6 @@
 #include "absl/container/flat_hash_map.h"
 #include "absl/log/log.h"
 #include "absl/status/status.h"
-#include "absl/strings/str_cat.h"
 #include "iamf/cli/channel_label.h"
 #include "iamf/cli/demixing_module.h"
 #include "iamf/common/macros.h"
@@ -67,11 +66,10 @@ absl::Status FindRelevantMixedSamples(
                                   {kDemixedR2, kMono}});
 
   ChannelLabel::Label relevant_mixed_label;
-  if (!LookupInMap(*kLabelToRelevantMixedLabel, label, relevant_mixed_label)
-           .ok()) {
-    return absl::InvalidArgumentError(absl::StrCat(
-        "Failed to find relevant mixed label associated with label= ", label));
-  }
+  RETURN_IF_NOT_OK(
+      CopyFromMap(*kLabelToRelevantMixedLabel, label,
+                  "`relevant_mixed_label` for demixed `ChannelLabel::Label`",
+                  relevant_mixed_label));
 
   LOG_IF(INFO, additional_logging)
       << "Relevant mixed samples has label: " << relevant_mixed_label;
diff --git a/iamf/cli/renderer/BUILD b/iamf/cli/renderer/BUILD
index a2e8964..69b9c32 100644
--- a/iamf/cli/renderer/BUILD
+++ b/iamf/cli/renderer/BUILD
@@ -58,6 +58,7 @@ cc_library(
         "//iamf/cli:channel_label",
         "//iamf/cli:demixing_module",
         "//iamf/common:macros",
+        "//iamf/common:obu_util",
         "//iamf/obu:mix_presentation",
         "//iamf/obu:types",
         "@com_google_absl//absl/base:no_destructor",
diff --git a/iamf/cli/renderer/audio_element_renderer_passthrough.cc b/iamf/cli/renderer/audio_element_renderer_passthrough.cc
index 198cdd2..a4ae4c7 100644
--- a/iamf/cli/renderer/audio_element_renderer_passthrough.cc
+++ b/iamf/cli/renderer/audio_element_renderer_passthrough.cc
@@ -15,7 +15,6 @@
 
 #include <algorithm>
 #include <memory>
-#include <new>
 #include <vector>
 
 #include "absl/base/no_destructor.h"
@@ -60,14 +59,13 @@ absl::StatusOr<bool> IsLoudspeakerLayoutEquivalentToSoundSystem(
           {kSoundSystem11_2_3_0, kLayout3_1_2_ch},
       });
 
-  const auto equivalent_loudspeaker_layout_iter =
-      kSoundSystemToLoudspeakerLayout->find(layout);
-  if (equivalent_loudspeaker_layout_iter ==
-      kSoundSystemToLoudspeakerLayout->end()) {
-    return absl::InvalidArgumentError(
-        absl::StrCat("Sound system not found for layout= ", layout));
-  }
-  return equivalent_loudspeaker_layout_iter->second == loudspeaker_layout;
+  ChannelAudioLayerConfig::LoudspeakerLayout equivalent_loudspeaker_layout;
+  RETURN_IF_NOT_OK(
+      CopyFromMap(*kSoundSystemToLoudspeakerLayout, layout,
+                  "`LoudspeakerLayout` equivalent to `SoundSystem`",
+                  equivalent_loudspeaker_layout));
+
+  return equivalent_loudspeaker_layout == loudspeaker_layout;
 }
 
 // Several expanded layouts are defined as being based on a particular sound
diff --git a/iamf/cli/renderer/renderer_utils.cc b/iamf/cli/renderer/renderer_utils.cc
index c865f6d..c281425 100644
--- a/iamf/cli/renderer/renderer_utils.cc
+++ b/iamf/cli/renderer/renderer_utils.cc
@@ -21,6 +21,7 @@
 #include "iamf/cli/channel_label.h"
 #include "iamf/cli/demixing_module.h"
 #include "iamf/common/macros.h"
+#include "iamf/common/obu_util.h"
 #include "iamf/obu/mix_presentation.h"
 #include "iamf/obu/types.h"
 
@@ -147,12 +148,8 @@ absl::StatusOr<std::string> LookupOutputKeyFromPlaybackLayout(
               {kSoundSystem13_6_9_0, "9.1.6"},
           });
 
-      auto it = kSoundSystemToOutputKey->find(sound_system);
-      if (it == kSoundSystemToOutputKey->end()) {
-        return absl::InvalidArgumentError(absl::StrCat(
-            "Output key not found for sound_system= ", sound_system));
-      }
-      return it->second;
+      return LookupInMap(*kSoundSystemToOutputKey, sound_system,
+                         "Output key for `SoundSystem`");
     }
 
     case kLayoutTypeBinaural:
diff --git a/iamf/common/obu_util.cc b/iamf/common/obu_util.cc
index a57563a..ef2946f 100644
--- a/iamf/common/obu_util.cc
+++ b/iamf/common/obu_util.cc
@@ -221,14 +221,14 @@ bool IsNativeBigEndian() {
 absl::Status ValidateVectorSizeEqual(const std::string& field_name,
                                      size_t vector_size,
                                      DecodedUleb128 obu_reported_size) {
-  if (vector_size != obu_reported_size) {
-    auto error_message = absl::StrCat(
-        "Found inconsistency with `", field_name, ".size()`= ", vector_size,
-        ". Expected a value of ", obu_reported_size, ".");
-    LOG(ERROR) << error_message;
-    return absl::InvalidArgumentError(error_message);
-  }
-  return absl::OkStatus();
+  if (vector_size == obu_reported_size) [[likely]] {
+    return absl::OkStatus();
+  }
+  auto error_message = absl::StrCat(
+      "Found inconsistency with `", field_name, ".size()`= ", vector_size,
+      ". Expected a value of ", obu_reported_size, ".");
+  LOG(ERROR) << error_message;
+  return absl::InvalidArgumentError(error_message);
 }
 
 }  // namespace iamf_tools
diff --git a/iamf/common/obu_util.h b/iamf/common/obu_util.h
index 75527d2..7f7d667 100644
--- a/iamf/common/obu_util.h
+++ b/iamf/common/obu_util.h
@@ -217,16 +217,64 @@ absl::Status ValidateVectorSizeEqual(const std::string& field_name,
                                      size_t vector_size,
                                      DecodedUleb128 obu_reported_size);
 
+/*!\brief Looks up a key in a map and returns a status or value.
+ *
+ * When lookup fails the error message will contain the `context` string
+ * followed by "= $KEY", where $KEY is the stringified `key`.
+ *
+ * Some mapping have sufficient context in the typenames, for example:
+ *   - Input Map: A map of `PersonName` to `Birthday`.
+ *   - Typename-based context: "`Birthday` for `PersonName`".
+ *   - Output message: "`Birthday` for `PersonName`= John was not found in the
+ *                       map.".
+ *
+ * Some mappings provide insufficient context in the typenames. Or the typenames
+ * would be easily confused. Variable names or phrases should be used as
+ * context:
+ *   - Input Map: A map of `absl::string_view` names to `int` ages.
+ *   - Variable-based context: "`age` for `name`".
+ *   - Phrase-based context: or "Age for name".
+ * Or:
+ *   - Input Map: A map of `proto::Type` to `iamf_tools::Type`.
+ *   - Phrase-based context: "Internal version of proto `Type`".
+ *
+ * \param map Map to search.
+ * \param key Key to search for.
+ * \param context Context to insert into the error message for debugging
+ *        purposes.
+ * \return Associated value if lookup is successful. `absl::NotFoundError()`
+ *         when lookup fails.
+ */
 template <typename T, typename U>
-absl::Status LookupInMap(const absl::flat_hash_map<T, U>& map, T key,
-                         U& value) {
+absl::StatusOr<U> LookupInMap(const absl::flat_hash_map<T, U>& map,
+                              const T& key, absl::string_view context) {
   auto iter = map.find(key);
-  if (iter == map.end()) {
-    return absl::InvalidArgumentError(
-        absl::StrCat("Key = ", key, " not found in the map."));
+  if (iter != map.end()) [[likely]] {
+    return iter->second;
   }
-  value = iter->second;
-  return absl::OkStatus();
+  return absl::NotFoundError(
+      absl::StrCat(context, "= ", key, " was not found in the map."));
+}
+
+/*!\brief Looks up a key in a map and copies the value to the output argument.
+ *
+ * \param map Map to search.
+ * \param key Key to search for.
+ * \param context Context to insert into the error message for debugging
+ *        purposes. Forwared to `LookupInMap` which has detailed documentation
+ *        on usage.
+ * \param value Output argument to write the value to.
+ * \return `absl::OkStatus()` if lookup is successful. `absl::NotFoundError()`
+ *         when lookup fails.
+ */
+template <typename T, typename U>
+absl::Status CopyFromMap(const absl::flat_hash_map<T, U>& map, const T& key,
+                         absl::string_view context, U& value) {
+  const auto& result = LookupInMap(map, key, context);
+  if (result.ok()) [[likely]] {
+    value = *result;
+  }
+  return result.status();
 }
 
 /*!\brief Returns `absl::OkStatus()` if the arguments are equal.
@@ -240,8 +288,8 @@ absl::Status LookupInMap(const absl::flat_hash_map<T, U>& map, T key,
  */
 template <typename T>
 absl::Status ValidateEqual(const T& lhs, const T& rhs,
-                           const std::string& context) {
-  if (lhs == rhs) {
+                           absl::string_view context) {
+  if (lhs == rhs) [[likely]] {
     return absl::OkStatus();
   }
 
@@ -260,8 +308,8 @@ absl::Status ValidateEqual(const T& lhs, const T& rhs,
  */
 template <typename T>
 absl::Status ValidateNotEqual(const T& lhs, const T& rhs,
-                              const std::string& context) {
-  if (lhs != rhs) {
+                              absl::string_view context) {
+  if (lhs != rhs) [[likely]] {
     return absl::OkStatus();
   }
 
@@ -279,8 +327,8 @@ absl::Status ValidateNotEqual(const T& lhs, const T& rhs,
  */
 template <typename T>
 absl::Status ValidateHasValue(const std::optional<T>& argument,
-                              const absl::string_view context) {
-  if (argument.has_value()) {
+                              absl::string_view context) {
+  if (argument.has_value()) [[likely]] {
     return absl::OkStatus();
   }
 
@@ -299,7 +347,7 @@ absl::Status ValidateHasValue(const std::optional<T>& argument,
  */
 template <class InputIt>
 absl::Status ValidateUnique(InputIt first, InputIt last,
-                            const std::string& context) {
+                            absl::string_view context) {
   absl::flat_hash_set<typename InputIt::value_type> seen_values;
 
   for (auto iter = first; iter != last; ++iter) {
diff --git a/iamf/common/tests/BUILD b/iamf/common/tests/BUILD
index ad9940e..c1e9477 100644
--- a/iamf/common/tests/BUILD
+++ b/iamf/common/tests/BUILD
@@ -19,6 +19,7 @@ cc_test(
         "//iamf/cli/tests:cli_test_utils",
         "//iamf/common:obu_util",
         "//iamf/common:write_bit_buffer",
+        "@com_google_absl//absl/container:flat_hash_map",
         "@com_google_absl//absl/status",
         "@com_google_absl//absl/status:status_matchers",
         "@com_google_absl//absl/strings:string_view",
diff --git a/iamf/common/tests/obu_util_test.cc b/iamf/common/tests/obu_util_test.cc
index d112828..b6dcdb6 100644
--- a/iamf/common/tests/obu_util_test.cc
+++ b/iamf/common/tests/obu_util_test.cc
@@ -20,6 +20,7 @@
 #include <optional>
 #include <vector>
 
+#include "absl/container/flat_hash_map.h"
 #include "absl/status/status.h"
 #include "absl/status/status_matchers.h"
 #include "absl/strings/string_view.h"
@@ -33,6 +34,10 @@ namespace iamf_tools {
 namespace {
 
 using ::absl_testing::IsOk;
+using ::absl_testing::IsOkAndHolds;
+using ::absl_testing::StatusIs;
+
+constexpr absl::string_view kOmitContext = "";
 
 TEST(AddUint32CheckOverflow, SmallInput) {
   uint32_t result;
@@ -792,45 +797,81 @@ TEST(WritePcmSample, InvalidOver32Bits) {
             absl::StatusCode::kInvalidArgument);
 }
 
+TEST(CopyFromMap, ReturnsOkWhenLookupSucceeds) {
+  const absl::flat_hash_map<int, bool> kIntegerToIsPrime = {
+      {1, false}, {2, true}, {3, true}, {4, false}};
+
+  bool result;
+  EXPECT_THAT(CopyFromMap(kIntegerToIsPrime, 3, kOmitContext, result), IsOk());
+
+  EXPECT_TRUE(result);
+}
+
+TEST(CopyFromMap, ReturnsStatusNotFoundWhenLookupFails) {
+  const absl::flat_hash_map<int, bool> kIntegerToIsPrime = {
+      {1, false}, {2, true}, {3, true}, {4, false}};
+
+  bool undefined_result;
+  EXPECT_THAT(
+      CopyFromMap(kIntegerToIsPrime, -1, kOmitContext, undefined_result),
+      StatusIs(absl::StatusCode::kNotFound));
+}
+
+TEST(LookupInMapStatusOr, OkIfLookupSucceeds) {
+  const absl::flat_hash_map<int, bool> kIntegerToIsPrime = {
+      {1, false}, {2, true}, {3, true}, {4, false}};
+
+  EXPECT_THAT(LookupInMap(kIntegerToIsPrime, 3, kOmitContext),
+              IsOkAndHolds(true));
+}
+
+TEST(LookupInMapStatusOr, ReturnsStatusNotFoundWhenLookupFails) {
+  const absl::flat_hash_map<int, bool> kIntegerToIsPrime = {
+      {1, false}, {2, true}, {3, true}, {4, false}};
+
+  EXPECT_THAT(LookupInMap(kIntegerToIsPrime, -1, kOmitContext),
+              StatusIs(absl::StatusCode::kNotFound));
+}
+
 TEST(ValidateEqual, OkIfArgsAreEqual) {
   const auto kLeftArg = 123;
   const auto kRightArg = 123;
-  EXPECT_THAT(ValidateEqual(kLeftArg, kRightArg, ""), IsOk());
+  EXPECT_THAT(ValidateEqual(kLeftArg, kRightArg, kOmitContext), IsOk());
 }
 
 TEST(ValidateEqual, NotOkIfArgsAreNotEqual) {
   const auto kLeftArg = 123;
   const auto kUnequalRightArg = 223;
-  EXPECT_FALSE(ValidateEqual(kLeftArg, kUnequalRightArg, "").ok());
+  EXPECT_FALSE(ValidateEqual(kLeftArg, kUnequalRightArg, kOmitContext).ok());
 }
 
 TEST(ValidateNotEqual, OkIfArgsAreNotEqual) {
   const auto kLeftArg = 123;
   const auto kRightArg = 124;
-  EXPECT_THAT(ValidateNotEqual(kLeftArg, kRightArg, ""), IsOk());
+  EXPECT_THAT(ValidateNotEqual(kLeftArg, kRightArg, kOmitContext), IsOk());
 }
 
 TEST(ValidateNotEqual, NotOkIfArgsAreEqual) {
   const auto kLeftArg = 123;
   const auto kEqualRightArg = 123;
-  EXPECT_FALSE(ValidateNotEqual(kLeftArg, kEqualRightArg, "").ok());
+  EXPECT_FALSE(ValidateNotEqual(kLeftArg, kEqualRightArg, kOmitContext).ok());
 }
 
 TEST(ValidateHasValue, OkIfArgHasValue) {
   constexpr std::optional<int> kArg = 123;
-  EXPECT_THAT(ValidateHasValue(kArg, ""), IsOk());
+  EXPECT_THAT(ValidateHasValue(kArg, kOmitContext), IsOk());
 }
 
 TEST(ValidateHasValue, NotOkIfArgDoesNotHaveValue) {
   constexpr std::optional<int> kArg = std::nullopt;
-  EXPECT_FALSE(ValidateHasValue(kArg, "").ok());
+  EXPECT_FALSE(ValidateHasValue(kArg, kOmitContext).ok());
 }
 
 TEST(ValidateUnique, OkIfArgsAreUnique) {
   const std::vector<int> kVectorWithUniqueValues = {1, 2, 3, 99};
 
   EXPECT_THAT(ValidateUnique(kVectorWithUniqueValues.begin(),
-                             kVectorWithUniqueValues.end(), ""),
+                             kVectorWithUniqueValues.end(), kOmitContext),
               IsOk());
 }
 
@@ -838,7 +879,7 @@ TEST(ValidateUnique, NotOkIfArgsAreNotUnique) {
   const std::vector<int> kVectorWithDuplicateValues = {1, 2, 3, 99, 1};
 
   EXPECT_FALSE(ValidateUnique(kVectorWithDuplicateValues.begin(),
-                              kVectorWithDuplicateValues.end(), "")
+                              kVectorWithDuplicateValues.end(), kOmitContext)
                    .ok());
 }
 
diff --git a/iamf/obu/mix_presentation.cc b/iamf/obu/mix_presentation.cc
index 546bced..c1deda3 100644
--- a/iamf/obu/mix_presentation.cc
+++ b/iamf/obu/mix_presentation.cc
@@ -432,14 +432,8 @@ absl::Status MixPresentationObu::GetNumChannelsFromLayout(
                                     loudness_layout.specific_layout)
                                     .sound_system;
 
-      if (!LookupInMap(*kSoundSystemToNumChannels, sound_system, num_channels)
-               .ok()) {
-        return absl::InvalidArgumentError(
-            absl::StrCat("Unknown number of channels for reserved or out of "
-                         "bounds sound_system= ",
-                         sound_system));
-      }
-      return absl::OkStatus();
+      return CopyFromMap(*kSoundSystemToNumChannels, sound_system,
+                         "Number of channels for `SoundSystem`", num_channels);
     }
     case kLayoutTypeReserved0:
     case kLayoutTypeReserved1: