From b6b62a94727652d0796afddfbd0e9c1abbde9407 Mon Sep 17 00:00:00 2001
From: Sangtaek Lee <sangteak601@gmail.com>
Date: Thu, 29 Feb 2024 06:12:17 +0000
Subject: [PATCH 01/19] Add simple bag reader example

Signed-off-by: Sangtaek Lee <sangteak601@gmail.com>
---
 .../rosbag2_examples_cpp/CMakeLists.txt       | 15 +++-
 .../rosbag2_examples_cpp/package.xml          |  1 +
 .../src/simple_bag_reader.cpp                 | 70 +++++++++++++++++++
 .../src/simple_bag_recorder.cpp               |  8 +--
 4 files changed, 89 insertions(+), 5 deletions(-)
 create mode 100644 rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_reader.cpp

diff --git a/rosbag2_examples/rosbag2_examples_cpp/CMakeLists.txt b/rosbag2_examples/rosbag2_examples_cpp/CMakeLists.txt
index 3e68057661..6f593b4947 100644
--- a/rosbag2_examples/rosbag2_examples_cpp/CMakeLists.txt
+++ b/rosbag2_examples/rosbag2_examples_cpp/CMakeLists.txt
@@ -20,13 +20,14 @@ endif()
 find_package(ament_cmake REQUIRED)
 find_package(rclcpp REQUIRED)
 find_package(rosbag2_cpp REQUIRED)
+find_package(std_msgs REQUIRED)
 find_package(example_interfaces REQUIRED)
 
 add_executable(simple_bag_recorder src/simple_bag_recorder.cpp)
 target_link_libraries(simple_bag_recorder
   rclcpp::rclcpp
   rosbag2_cpp::rosbag2_cpp
-  ${example_interfaces_TARGETS}
+  ${std_msgs_TARGETS}
 )
 
 install(TARGETS
@@ -58,6 +59,18 @@ install(TARGETS
   DESTINATION lib/${PROJECT_NAME}
 )
 
+add_executable(simple_bag_reader src/simple_bag_reader.cpp)
+target_link_libraries(simple_bag_reader
+  rclcpp::rclcpp
+  rosbag2_cpp::rosbag2_cpp
+  ${std_msgs_TARGETS}
+)
+
+install(TARGETS
+  simple_bag_reader
+  DESTINATION lib/${PROJECT_NAME}
+)
+
 if(BUILD_TESTING)
   find_package(ament_lint_auto REQUIRED)
   ament_lint_auto_find_test_dependencies()
diff --git a/rosbag2_examples/rosbag2_examples_cpp/package.xml b/rosbag2_examples/rosbag2_examples_cpp/package.xml
index 81b204f613..6a2f6a265c 100644
--- a/rosbag2_examples/rosbag2_examples_cpp/package.xml
+++ b/rosbag2_examples/rosbag2_examples_cpp/package.xml
@@ -13,6 +13,7 @@
 
   <depend>rclcpp</depend>
   <depend>rosbag2_cpp</depend>
+  <depend>std_msgs</depend>
   <depend>example_interfaces</depend>
 
   <test_depend>ament_lint_auto</test_depend>
diff --git a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_reader.cpp b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_reader.cpp
new file mode 100644
index 0000000000..fce7a33e4f
--- /dev/null
+++ b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_reader.cpp
@@ -0,0 +1,70 @@
+#include <chrono>
+#include <functional>
+#include <iostream>
+#include <memory>
+#include <string>
+
+#include "rclcpp/rclcpp.hpp"
+#include "rclcpp/serialization.hpp"
+#include "rosbag2_cpp/reader.hpp"
+#include "std_msgs/msg/string.hpp"
+
+using namespace std::chrono_literals;
+
+class PlaybackNode : public rclcpp::Node
+{
+  public:
+    PlaybackNode(const std::string & bag_filename)
+    : Node("playback_node")
+    {
+      publisher_ = this->create_publisher<std_msgs::msg::String>("chatter", 10);
+
+      timer_ = this->create_wall_timer(100ms,
+          [this](){return this->timer_callback();}
+      );
+
+      reader_.open(bag_filename);
+    }
+
+  private:
+    void timer_callback()
+    {
+      while (reader_.has_next()) {
+        rosbag2_storage::SerializedBagMessageSharedPtr msg = reader_.read_next();
+
+        if (msg->topic_name != "/turtle1/pose") {
+          continue;
+        }
+
+        rclcpp::SerializedMessage serialized_msg(*msg->serialized_data);
+        std_msgs::msg::String::SharedPtr ros_msg = std::make_shared<std_msgs::msg::String>();
+
+        serialization_.deserialize_message(&serialized_msg, ros_msg.get());
+
+        publisher_->publish(*ros_msg);
+        std::cout << ros_msg->data << "\n";
+
+        break;
+      }
+    }
+
+    rclcpp::TimerBase::SharedPtr timer_;
+    rclcpp::Publisher<std_msgs::msg::String>::SharedPtr publisher_;
+
+    rclcpp::Serialization<std_msgs::msg::String> serialization_;
+    rosbag2_cpp::Reader reader_;
+};
+
+int main(int argc, char ** argv)
+{
+  if (argc != 2) {
+    std::cerr << "Usage: " << argv[0] << " <bag>" << std::endl;
+    return 1;
+  }
+
+  rclcpp::init(argc, argv);
+  rclcpp::spin(std::make_shared<PlaybackNode>(argv[1]));
+  rclcpp::shutdown();
+
+  return 0;
+}
\ No newline at end of file
diff --git a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_recorder.cpp b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_recorder.cpp
index b6535d40db..b2910ab0c4 100644
--- a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_recorder.cpp
+++ b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_recorder.cpp
@@ -14,7 +14,7 @@
 
 #include <memory>
 
-#include "example_interfaces/msg/string.hpp"
+#include "std_msgs/msg/string.hpp"
 #include "rclcpp/rclcpp.hpp"
 
 #include "rosbag2_cpp/writer.hpp"
@@ -31,7 +31,7 @@ class SimpleBagRecorder : public rclcpp::Node
 
     writer_->open("my_bag");
 
-    subscription_ = create_subscription<example_interfaces::msg::String>(
+    subscription_ = create_subscription<std_msgs::msg::String>(
       "chatter", 10, std::bind(&SimpleBagRecorder::topic_callback, this, _1));
   }
 
@@ -39,10 +39,10 @@ class SimpleBagRecorder : public rclcpp::Node
   void topic_callback(std::shared_ptr<rclcpp::SerializedMessage> msg) const
   {
     rclcpp::Time time_stamp = this->now();
-    writer_->write(msg, "chatter", "example_interfaces/msg/String", time_stamp);
+    writer_->write(msg, "chatter", "std_msgs/msg/String", time_stamp);
   }
 
-  rclcpp::Subscription<example_interfaces::msg::String>::SharedPtr subscription_;
+  rclcpp::Subscription<std_msgs::msg::String>::SharedPtr subscription_;
   std::unique_ptr<rosbag2_cpp::Writer> writer_;
 };
 

From 2ba65462b9f34e6e7c1ff0099cda81ee2f21d36e Mon Sep 17 00:00:00 2001
From: Sangtaek Lee <sangteak601@gmail.com>
Date: Fri, 1 Mar 2024 07:07:03 +0000
Subject: [PATCH 02/19] revert topic interface

Signed-off-by: Sangtaek Lee <sangteak601@gmail.com>
---
 rosbag2_examples/rosbag2_examples_cpp/CMakeLists.txt |  5 ++---
 .../rosbag2_examples_cpp/src/simple_bag_reader.cpp   | 12 ++++++------
 .../rosbag2_examples_cpp/src/simple_bag_recorder.cpp |  8 ++++----
 3 files changed, 12 insertions(+), 13 deletions(-)

diff --git a/rosbag2_examples/rosbag2_examples_cpp/CMakeLists.txt b/rosbag2_examples/rosbag2_examples_cpp/CMakeLists.txt
index 6f593b4947..6c9dc2c532 100644
--- a/rosbag2_examples/rosbag2_examples_cpp/CMakeLists.txt
+++ b/rosbag2_examples/rosbag2_examples_cpp/CMakeLists.txt
@@ -20,14 +20,13 @@ endif()
 find_package(ament_cmake REQUIRED)
 find_package(rclcpp REQUIRED)
 find_package(rosbag2_cpp REQUIRED)
-find_package(std_msgs REQUIRED)
 find_package(example_interfaces REQUIRED)
 
 add_executable(simple_bag_recorder src/simple_bag_recorder.cpp)
 target_link_libraries(simple_bag_recorder
   rclcpp::rclcpp
   rosbag2_cpp::rosbag2_cpp
-  ${std_msgs_TARGETS}
+  ${example_interfaces_TARGETS}
 )
 
 install(TARGETS
@@ -63,7 +62,7 @@ add_executable(simple_bag_reader src/simple_bag_reader.cpp)
 target_link_libraries(simple_bag_reader
   rclcpp::rclcpp
   rosbag2_cpp::rosbag2_cpp
-  ${std_msgs_TARGETS}
+  ${example_interfaces_TARGETS}
 )
 
 install(TARGETS
diff --git a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_reader.cpp b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_reader.cpp
index fce7a33e4f..614d30b1b9 100644
--- a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_reader.cpp
+++ b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_reader.cpp
@@ -7,7 +7,7 @@
 #include "rclcpp/rclcpp.hpp"
 #include "rclcpp/serialization.hpp"
 #include "rosbag2_cpp/reader.hpp"
-#include "std_msgs/msg/string.hpp"
+#include "example_interfaces/msg/string.hpp"
 
 using namespace std::chrono_literals;
 
@@ -17,7 +17,7 @@ class PlaybackNode : public rclcpp::Node
     PlaybackNode(const std::string & bag_filename)
     : Node("playback_node")
     {
-      publisher_ = this->create_publisher<std_msgs::msg::String>("chatter", 10);
+      publisher_ = this->create_publisher<example_interfaces::msg::String>("chatter", 10);
 
       timer_ = this->create_wall_timer(100ms,
           [this](){return this->timer_callback();}
@@ -32,12 +32,12 @@ class PlaybackNode : public rclcpp::Node
       while (reader_.has_next()) {
         rosbag2_storage::SerializedBagMessageSharedPtr msg = reader_.read_next();
 
-        if (msg->topic_name != "/turtle1/pose") {
+        if (msg->topic_name != "/chatter") {
           continue;
         }
 
         rclcpp::SerializedMessage serialized_msg(*msg->serialized_data);
-        std_msgs::msg::String::SharedPtr ros_msg = std::make_shared<std_msgs::msg::String>();
+        example_interfaces::msg::String::SharedPtr ros_msg = std::make_shared<example_interfaces::msg::String>();
 
         serialization_.deserialize_message(&serialized_msg, ros_msg.get());
 
@@ -49,9 +49,9 @@ class PlaybackNode : public rclcpp::Node
     }
 
     rclcpp::TimerBase::SharedPtr timer_;
-    rclcpp::Publisher<std_msgs::msg::String>::SharedPtr publisher_;
+    rclcpp::Publisher<example_interfaces::msg::String>::SharedPtr publisher_;
 
-    rclcpp::Serialization<std_msgs::msg::String> serialization_;
+    rclcpp::Serialization<example_interfaces::msg::String> serialization_;
     rosbag2_cpp::Reader reader_;
 };
 
diff --git a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_recorder.cpp b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_recorder.cpp
index b2910ab0c4..b6535d40db 100644
--- a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_recorder.cpp
+++ b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_recorder.cpp
@@ -14,7 +14,7 @@
 
 #include <memory>
 
-#include "std_msgs/msg/string.hpp"
+#include "example_interfaces/msg/string.hpp"
 #include "rclcpp/rclcpp.hpp"
 
 #include "rosbag2_cpp/writer.hpp"
@@ -31,7 +31,7 @@ class SimpleBagRecorder : public rclcpp::Node
 
     writer_->open("my_bag");
 
-    subscription_ = create_subscription<std_msgs::msg::String>(
+    subscription_ = create_subscription<example_interfaces::msg::String>(
       "chatter", 10, std::bind(&SimpleBagRecorder::topic_callback, this, _1));
   }
 
@@ -39,10 +39,10 @@ class SimpleBagRecorder : public rclcpp::Node
   void topic_callback(std::shared_ptr<rclcpp::SerializedMessage> msg) const
   {
     rclcpp::Time time_stamp = this->now();
-    writer_->write(msg, "chatter", "std_msgs/msg/String", time_stamp);
+    writer_->write(msg, "chatter", "example_interfaces/msg/String", time_stamp);
   }
 
-  rclcpp::Subscription<std_msgs::msg::String>::SharedPtr subscription_;
+  rclcpp::Subscription<example_interfaces::msg::String>::SharedPtr subscription_;
   std::unique_ptr<rosbag2_cpp::Writer> writer_;
 };
 

From b2c9893aa8658c5cca6c4e05628bbe18ccce7961 Mon Sep 17 00:00:00 2001
From: Sangtaek Lee <sangteak601@gmail.com>
Date: Fri, 1 Mar 2024 07:13:32 +0000
Subject: [PATCH 03/19] change topic name

Signed-off-by: Sangtaek Lee <sangteak601@gmail.com>
---
 rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_reader.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_reader.cpp b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_reader.cpp
index 614d30b1b9..77ae805a6d 100644
--- a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_reader.cpp
+++ b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_reader.cpp
@@ -32,7 +32,7 @@ class PlaybackNode : public rclcpp::Node
       while (reader_.has_next()) {
         rosbag2_storage::SerializedBagMessageSharedPtr msg = reader_.read_next();
 
-        if (msg->topic_name != "/chatter") {
+        if (msg->topic_name != "chatter") {
           continue;
         }
 

From ed349bea610201579de6be8e30a79e1fd31aeb77 Mon Sep 17 00:00:00 2001
From: Sangtaek Lee <sangteak601@gmail.com>
Date: Fri, 1 Mar 2024 07:39:21 +0000
Subject: [PATCH 04/19] delete unnecessary dependency

Signed-off-by: Sangtaek Lee <sangteak601@gmail.com>
---
 rosbag2_examples/rosbag2_examples_cpp/package.xml | 1 -
 1 file changed, 1 deletion(-)

diff --git a/rosbag2_examples/rosbag2_examples_cpp/package.xml b/rosbag2_examples/rosbag2_examples_cpp/package.xml
index 6a2f6a265c..81b204f613 100644
--- a/rosbag2_examples/rosbag2_examples_cpp/package.xml
+++ b/rosbag2_examples/rosbag2_examples_cpp/package.xml
@@ -13,7 +13,6 @@
 
   <depend>rclcpp</depend>
   <depend>rosbag2_cpp</depend>
-  <depend>std_msgs</depend>
   <depend>example_interfaces</depend>
 
   <test_depend>ament_lint_auto</test_depend>

From 2a2b97b4d09a4cdc01a0f00d6463562864bddada Mon Sep 17 00:00:00 2001
From: Sangtaek Lee <sangteak601@gmail.com>
Date: Tue, 5 Mar 2024 06:53:01 +0000
Subject: [PATCH 05/19] update simple_bag_player

Signed-off-by: Sangtaek Lee <sangteak601@gmail.com>
---
 .../rosbag2_examples_cpp/CMakeLists.txt       |  6 ++--
 ...e_bag_reader.cpp => simple_bag_player.cpp} | 30 +++++++++----------
 2 files changed, 18 insertions(+), 18 deletions(-)
 rename rosbag2_examples/rosbag2_examples_cpp/src/{simple_bag_reader.cpp => simple_bag_player.cpp} (63%)

diff --git a/rosbag2_examples/rosbag2_examples_cpp/CMakeLists.txt b/rosbag2_examples/rosbag2_examples_cpp/CMakeLists.txt
index 6c9dc2c532..de761a5af2 100644
--- a/rosbag2_examples/rosbag2_examples_cpp/CMakeLists.txt
+++ b/rosbag2_examples/rosbag2_examples_cpp/CMakeLists.txt
@@ -58,15 +58,15 @@ install(TARGETS
   DESTINATION lib/${PROJECT_NAME}
 )
 
-add_executable(simple_bag_reader src/simple_bag_reader.cpp)
-target_link_libraries(simple_bag_reader
+add_executable(simple_bag_player src/simple_bag_player.cpp)
+target_link_libraries(simple_bag_player
   rclcpp::rclcpp
   rosbag2_cpp::rosbag2_cpp
   ${example_interfaces_TARGETS}
 )
 
 install(TARGETS
-  simple_bag_reader
+  simple_bag_player
   DESTINATION lib/${PROJECT_NAME}
 )
 
diff --git a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_reader.cpp b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp
similarity index 63%
rename from rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_reader.cpp
rename to rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp
index 77ae805a6d..c5e7dcb763 100644
--- a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_reader.cpp
+++ b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp
@@ -6,6 +6,7 @@
 
 #include "rclcpp/rclcpp.hpp"
 #include "rclcpp/serialization.hpp"
+#include "rosbag2_storage/qos.hpp"
 #include "rosbag2_cpp/reader.hpp"
 #include "example_interfaces/msg/string.hpp"
 
@@ -17,13 +18,19 @@ class PlaybackNode : public rclcpp::Node
     PlaybackNode(const std::string & bag_filename)
     : Node("playback_node")
     {
-      publisher_ = this->create_publisher<example_interfaces::msg::String>("chatter", 10);
+      reader_.open(bag_filename);
+
+      auto topics = reader_.get_all_topics_and_types();
+
+      for (const auto & topic : topics) {
+        if (topic.name == TOPIC_NAME) {
+          publisher_ = create_generic_publisher(topic.name, topic.type, rosbag2_storage::Rosbag2QoS{});
+        }
+      }
 
       timer_ = this->create_wall_timer(100ms,
           [this](){return this->timer_callback();}
       );
-
-      reader_.open(bag_filename);
     }
 
   private:
@@ -31,28 +38,21 @@ class PlaybackNode : public rclcpp::Node
     {
       while (reader_.has_next()) {
         rosbag2_storage::SerializedBagMessageSharedPtr msg = reader_.read_next();
-
-        if (msg->topic_name != "chatter") {
+        if (msg->topic_name != TOPIC_NAME) {
           continue;
         }
-
-        rclcpp::SerializedMessage serialized_msg(*msg->serialized_data);
-        example_interfaces::msg::String::SharedPtr ros_msg = std::make_shared<example_interfaces::msg::String>();
-
-        serialization_.deserialize_message(&serialized_msg, ros_msg.get());
-
-        publisher_->publish(*ros_msg);
-        std::cout << ros_msg->data << "\n";
+        publisher_->publish(rclcpp::SerializedMessage(*msg->serialized_data));
 
         break;
       }
     }
 
     rclcpp::TimerBase::SharedPtr timer_;
-    rclcpp::Publisher<example_interfaces::msg::String>::SharedPtr publisher_;
+    std::shared_ptr<rclcpp::GenericPublisher> publisher_;
 
-    rclcpp::Serialization<example_interfaces::msg::String> serialization_;
     rosbag2_cpp::Reader reader_;
+
+    const std::string TOPIC_NAME {"chatter"};
 };
 
 int main(int argc, char ** argv)

From 7f360444ff2eba2c02a57b792abd565fd60324bc Mon Sep 17 00:00:00 2001
From: Sangtaek Lee <sangteak601@gmail.com>
Date: Tue, 5 Mar 2024 07:13:04 +0000
Subject: [PATCH 06/19] Revert "update simple_bag_player"

This reverts commit 24f9565af84e3bc01509e485bba6c417b34b268d.

Signed-off-by: Sangtaek Lee <sangteak601@gmail.com>
---
 .../rosbag2_examples_cpp/CMakeLists.txt       |  6 ++--
 ...e_bag_player.cpp => simple_bag_reader.cpp} | 30 +++++++++----------
 2 files changed, 18 insertions(+), 18 deletions(-)
 rename rosbag2_examples/rosbag2_examples_cpp/src/{simple_bag_player.cpp => simple_bag_reader.cpp} (63%)

diff --git a/rosbag2_examples/rosbag2_examples_cpp/CMakeLists.txt b/rosbag2_examples/rosbag2_examples_cpp/CMakeLists.txt
index de761a5af2..6c9dc2c532 100644
--- a/rosbag2_examples/rosbag2_examples_cpp/CMakeLists.txt
+++ b/rosbag2_examples/rosbag2_examples_cpp/CMakeLists.txt
@@ -58,15 +58,15 @@ install(TARGETS
   DESTINATION lib/${PROJECT_NAME}
 )
 
-add_executable(simple_bag_player src/simple_bag_player.cpp)
-target_link_libraries(simple_bag_player
+add_executable(simple_bag_reader src/simple_bag_reader.cpp)
+target_link_libraries(simple_bag_reader
   rclcpp::rclcpp
   rosbag2_cpp::rosbag2_cpp
   ${example_interfaces_TARGETS}
 )
 
 install(TARGETS
-  simple_bag_player
+  simple_bag_reader
   DESTINATION lib/${PROJECT_NAME}
 )
 
diff --git a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_reader.cpp
similarity index 63%
rename from rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp
rename to rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_reader.cpp
index c5e7dcb763..77ae805a6d 100644
--- a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp
+++ b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_reader.cpp
@@ -6,7 +6,6 @@
 
 #include "rclcpp/rclcpp.hpp"
 #include "rclcpp/serialization.hpp"
-#include "rosbag2_storage/qos.hpp"
 #include "rosbag2_cpp/reader.hpp"
 #include "example_interfaces/msg/string.hpp"
 
@@ -18,19 +17,13 @@ class PlaybackNode : public rclcpp::Node
     PlaybackNode(const std::string & bag_filename)
     : Node("playback_node")
     {
-      reader_.open(bag_filename);
-
-      auto topics = reader_.get_all_topics_and_types();
-
-      for (const auto & topic : topics) {
-        if (topic.name == TOPIC_NAME) {
-          publisher_ = create_generic_publisher(topic.name, topic.type, rosbag2_storage::Rosbag2QoS{});
-        }
-      }
+      publisher_ = this->create_publisher<example_interfaces::msg::String>("chatter", 10);
 
       timer_ = this->create_wall_timer(100ms,
           [this](){return this->timer_callback();}
       );
+
+      reader_.open(bag_filename);
     }
 
   private:
@@ -38,21 +31,28 @@ class PlaybackNode : public rclcpp::Node
     {
       while (reader_.has_next()) {
         rosbag2_storage::SerializedBagMessageSharedPtr msg = reader_.read_next();
-        if (msg->topic_name != TOPIC_NAME) {
+
+        if (msg->topic_name != "chatter") {
           continue;
         }
-        publisher_->publish(rclcpp::SerializedMessage(*msg->serialized_data));
+
+        rclcpp::SerializedMessage serialized_msg(*msg->serialized_data);
+        example_interfaces::msg::String::SharedPtr ros_msg = std::make_shared<example_interfaces::msg::String>();
+
+        serialization_.deserialize_message(&serialized_msg, ros_msg.get());
+
+        publisher_->publish(*ros_msg);
+        std::cout << ros_msg->data << "\n";
 
         break;
       }
     }
 
     rclcpp::TimerBase::SharedPtr timer_;
-    std::shared_ptr<rclcpp::GenericPublisher> publisher_;
+    rclcpp::Publisher<example_interfaces::msg::String>::SharedPtr publisher_;
 
+    rclcpp::Serialization<example_interfaces::msg::String> serialization_;
     rosbag2_cpp::Reader reader_;
-
-    const std::string TOPIC_NAME {"chatter"};
 };
 
 int main(int argc, char ** argv)

From 21876b53ee63260af36fc267514bb0b60adce16d Mon Sep 17 00:00:00 2001
From: Sangtaek Lee <sangteak601@gmail.com>
Date: Tue, 5 Mar 2024 07:15:45 +0000
Subject: [PATCH 07/19] rename reader

Signed-off-by: Sangtaek Lee <sangteak601@gmail.com>
---
 rosbag2_examples/rosbag2_examples_cpp/CMakeLists.txt        | 6 +++---
 .../src/{simple_bag_reader.cpp => simple_bag_player.cpp}    | 6 +++---
 2 files changed, 6 insertions(+), 6 deletions(-)
 rename rosbag2_examples/rosbag2_examples_cpp/src/{simple_bag_reader.cpp => simple_bag_player.cpp} (91%)

diff --git a/rosbag2_examples/rosbag2_examples_cpp/CMakeLists.txt b/rosbag2_examples/rosbag2_examples_cpp/CMakeLists.txt
index 6c9dc2c532..de761a5af2 100644
--- a/rosbag2_examples/rosbag2_examples_cpp/CMakeLists.txt
+++ b/rosbag2_examples/rosbag2_examples_cpp/CMakeLists.txt
@@ -58,15 +58,15 @@ install(TARGETS
   DESTINATION lib/${PROJECT_NAME}
 )
 
-add_executable(simple_bag_reader src/simple_bag_reader.cpp)
-target_link_libraries(simple_bag_reader
+add_executable(simple_bag_player src/simple_bag_player.cpp)
+target_link_libraries(simple_bag_player
   rclcpp::rclcpp
   rosbag2_cpp::rosbag2_cpp
   ${example_interfaces_TARGETS}
 )
 
 install(TARGETS
-  simple_bag_reader
+  simple_bag_player
   DESTINATION lib/${PROJECT_NAME}
 )
 
diff --git a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_reader.cpp b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp
similarity index 91%
rename from rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_reader.cpp
rename to rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp
index 77ae805a6d..21b19d54f5 100644
--- a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_reader.cpp
+++ b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp
@@ -11,10 +11,10 @@
 
 using namespace std::chrono_literals;
 
-class PlaybackNode : public rclcpp::Node
+class SimpleBagPlayer : public rclcpp::Node
 {
   public:
-    PlaybackNode(const std::string & bag_filename)
+    SimpleBagPlayer(const std::string & bag_filename)
     : Node("playback_node")
     {
       publisher_ = this->create_publisher<example_interfaces::msg::String>("chatter", 10);
@@ -63,7 +63,7 @@ int main(int argc, char ** argv)
   }
 
   rclcpp::init(argc, argv);
-  rclcpp::spin(std::make_shared<PlaybackNode>(argv[1]));
+  rclcpp::spin(std::make_shared<SimpleBagPlayer>(argv[1]));
   rclcpp::shutdown();
 
   return 0;

From 67fe8fb37bb04820b44e99ce99dfe6c394bfa32d Mon Sep 17 00:00:00 2001
From: Sangtaek Lee <sangteak601@gmail.com>
Date: Tue, 5 Mar 2024 07:49:58 +0000
Subject: [PATCH 08/19] add pytho simple bag player

Signed-off-by: Sangtaek Lee <sangteak601@gmail.com>
---
 .../rosbag2_examples_py/simple_bag_player.py  | 55 +++++++++++++++++++
 rosbag2_examples/rosbag2_examples_py/setup.py |  1 +
 2 files changed, 56 insertions(+)
 create mode 100644 rosbag2_examples/rosbag2_examples_py/rosbag2_examples_py/simple_bag_player.py

diff --git a/rosbag2_examples/rosbag2_examples_py/rosbag2_examples_py/simple_bag_player.py b/rosbag2_examples/rosbag2_examples_py/rosbag2_examples_py/simple_bag_player.py
new file mode 100644
index 0000000000..75e8bdf37d
--- /dev/null
+++ b/rosbag2_examples/rosbag2_examples_py/rosbag2_examples_py/simple_bag_player.py
@@ -0,0 +1,55 @@
+# Copyright 2023 Open Source Robotics Foundation, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+import sys
+import rclpy
+from rclpy.node import Node
+from rclpy.serialization import deserialize_message
+import rosbag2_py
+from std_msgs.msg import String
+
+
+class SimpleBagPlayer(Node):
+
+    def __init__(self, bag_filename):
+        super().__init__('simple_bag_player')
+        self.reader = rosbag2_py.SequentialReader()
+        storage_options = rosbag2_py._storage.StorageOptions(
+            uri='my_bag',
+            storage_id='sqlite3')
+        converter_options = rosbag2_py._storage.ConverterOptions('', '')
+        self.reader.open(storage_options, converter_options)
+
+        self.publisher = self.create_publisher(String, 'chatter', 10)
+        self.timer = self.create_timer(0.1, self.timer_callback)
+
+    def timer_callback(self):
+        while self.reader.has_next():
+            msg = self.reader.read_next()
+            if msg[0] != 'chatter':
+                continue
+            ros_msg = deserialize_message(msg[1], String)
+            self.publisher.publish(ros_msg)
+            self.get_logger().info(ros_msg.data)
+
+
+
+def main(args=None):
+    rclpy.init(args=args)
+    sbr = SimpleBagPlayer(sys.argv[1])
+    rclpy.spin(sbr)
+    rclpy.shutdown()
+
+
+if __name__ == '__main__':
+    main()
diff --git a/rosbag2_examples/rosbag2_examples_py/setup.py b/rosbag2_examples/rosbag2_examples_py/setup.py
index 1fa813cd71..16dfe1c72c 100644
--- a/rosbag2_examples/rosbag2_examples_py/setup.py
+++ b/rosbag2_examples/rosbag2_examples_py/setup.py
@@ -21,6 +21,7 @@
     entry_points={
         'console_scripts': [
             'simple_bag_recorder = rosbag2_examples_py.simple_bag_recorder:main',
+            'simple_bag_player = rosbag2_examples_py.simple_bag_player:main',
             'data_generator_node = rosbag2_examples_py.data_generator_node:main',
             'data_generator_executable = rosbag2_examples_py.data_generator_executable:main',
         ],

From cbac86202fa9fecd93c043522044ecf6de00592a Mon Sep 17 00:00:00 2001
From: Sangtaek Lee <sangteak601@gmail.com>
Date: Tue, 5 Mar 2024 07:51:16 +0000
Subject: [PATCH 09/19] get filename from arguments

Signed-off-by: Sangtaek Lee <sangteak601@gmail.com>
---
 .../rosbag2_examples_py/simple_bag_player.py                    | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/rosbag2_examples/rosbag2_examples_py/rosbag2_examples_py/simple_bag_player.py b/rosbag2_examples/rosbag2_examples_py/rosbag2_examples_py/simple_bag_player.py
index 75e8bdf37d..da897e1d69 100644
--- a/rosbag2_examples/rosbag2_examples_py/rosbag2_examples_py/simple_bag_player.py
+++ b/rosbag2_examples/rosbag2_examples_py/rosbag2_examples_py/simple_bag_player.py
@@ -25,7 +25,7 @@ def __init__(self, bag_filename):
         super().__init__('simple_bag_player')
         self.reader = rosbag2_py.SequentialReader()
         storage_options = rosbag2_py._storage.StorageOptions(
-            uri='my_bag',
+            uri=bag_filename,
             storage_id='sqlite3')
         converter_options = rosbag2_py._storage.ConverterOptions('', '')
         self.reader.open(storage_options, converter_options)

From 76f6b4b346818ae25916333acb011baf65f80a7f Mon Sep 17 00:00:00 2001
From: Sangtaek Lee <sangteak601@gmail.com>
Date: Wed, 6 Mar 2024 06:14:43 +0000
Subject: [PATCH 10/19] change msg type to std_msgs

Signed-off-by: Sangtaek Lee <sangteak601@gmail.com>
---
 rosbag2_examples/rosbag2_examples_cpp/CMakeLists.txt   |  5 +++--
 rosbag2_examples/rosbag2_examples_cpp/package.xml      |  1 +
 .../rosbag2_examples_cpp/src/simple_bag_player.cpp     | 10 +++++-----
 .../rosbag2_examples_cpp/src/simple_bag_recorder.cpp   |  8 ++++----
 4 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/rosbag2_examples/rosbag2_examples_cpp/CMakeLists.txt b/rosbag2_examples/rosbag2_examples_cpp/CMakeLists.txt
index de761a5af2..24cf155337 100644
--- a/rosbag2_examples/rosbag2_examples_cpp/CMakeLists.txt
+++ b/rosbag2_examples/rosbag2_examples_cpp/CMakeLists.txt
@@ -21,12 +21,13 @@ find_package(ament_cmake REQUIRED)
 find_package(rclcpp REQUIRED)
 find_package(rosbag2_cpp REQUIRED)
 find_package(example_interfaces REQUIRED)
+find_package(std_msgs REQUIRED)
 
 add_executable(simple_bag_recorder src/simple_bag_recorder.cpp)
 target_link_libraries(simple_bag_recorder
   rclcpp::rclcpp
   rosbag2_cpp::rosbag2_cpp
-  ${example_interfaces_TARGETS}
+  ${std_msgs_TARGETS}
 )
 
 install(TARGETS
@@ -62,7 +63,7 @@ add_executable(simple_bag_player src/simple_bag_player.cpp)
 target_link_libraries(simple_bag_player
   rclcpp::rclcpp
   rosbag2_cpp::rosbag2_cpp
-  ${example_interfaces_TARGETS}
+  ${std_msgs_TARGETS}
 )
 
 install(TARGETS
diff --git a/rosbag2_examples/rosbag2_examples_cpp/package.xml b/rosbag2_examples/rosbag2_examples_cpp/package.xml
index 81b204f613..1db0095690 100644
--- a/rosbag2_examples/rosbag2_examples_cpp/package.xml
+++ b/rosbag2_examples/rosbag2_examples_cpp/package.xml
@@ -14,6 +14,7 @@
   <depend>rclcpp</depend>
   <depend>rosbag2_cpp</depend>
   <depend>example_interfaces</depend>
+  <depend>std_msgs</depend>
 
   <test_depend>ament_lint_auto</test_depend>
   <test_depend>ament_lint_common</test_depend>
diff --git a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp
index 21b19d54f5..124c005853 100644
--- a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp
+++ b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp
@@ -7,7 +7,7 @@
 #include "rclcpp/rclcpp.hpp"
 #include "rclcpp/serialization.hpp"
 #include "rosbag2_cpp/reader.hpp"
-#include "example_interfaces/msg/string.hpp"
+#include "std_msgs/msg/string.hpp"
 
 using namespace std::chrono_literals;
 
@@ -17,7 +17,7 @@ class SimpleBagPlayer : public rclcpp::Node
     SimpleBagPlayer(const std::string & bag_filename)
     : Node("playback_node")
     {
-      publisher_ = this->create_publisher<example_interfaces::msg::String>("chatter", 10);
+      publisher_ = this->create_publisher<std_msgs::msg::String>("chatter", 10);
 
       timer_ = this->create_wall_timer(100ms,
           [this](){return this->timer_callback();}
@@ -37,7 +37,7 @@ class SimpleBagPlayer : public rclcpp::Node
         }
 
         rclcpp::SerializedMessage serialized_msg(*msg->serialized_data);
-        example_interfaces::msg::String::SharedPtr ros_msg = std::make_shared<example_interfaces::msg::String>();
+        std_msgs::msg::String::SharedPtr ros_msg = std::make_shared<std_msgs::msg::String>();
 
         serialization_.deserialize_message(&serialized_msg, ros_msg.get());
 
@@ -49,9 +49,9 @@ class SimpleBagPlayer : public rclcpp::Node
     }
 
     rclcpp::TimerBase::SharedPtr timer_;
-    rclcpp::Publisher<example_interfaces::msg::String>::SharedPtr publisher_;
+    rclcpp::Publisher<std_msgs::msg::String>::SharedPtr publisher_;
 
-    rclcpp::Serialization<example_interfaces::msg::String> serialization_;
+    rclcpp::Serialization<std_msgs::msg::String> serialization_;
     rosbag2_cpp::Reader reader_;
 };
 
diff --git a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_recorder.cpp b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_recorder.cpp
index b6535d40db..b2910ab0c4 100644
--- a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_recorder.cpp
+++ b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_recorder.cpp
@@ -14,7 +14,7 @@
 
 #include <memory>
 
-#include "example_interfaces/msg/string.hpp"
+#include "std_msgs/msg/string.hpp"
 #include "rclcpp/rclcpp.hpp"
 
 #include "rosbag2_cpp/writer.hpp"
@@ -31,7 +31,7 @@ class SimpleBagRecorder : public rclcpp::Node
 
     writer_->open("my_bag");
 
-    subscription_ = create_subscription<example_interfaces::msg::String>(
+    subscription_ = create_subscription<std_msgs::msg::String>(
       "chatter", 10, std::bind(&SimpleBagRecorder::topic_callback, this, _1));
   }
 
@@ -39,10 +39,10 @@ class SimpleBagRecorder : public rclcpp::Node
   void topic_callback(std::shared_ptr<rclcpp::SerializedMessage> msg) const
   {
     rclcpp::Time time_stamp = this->now();
-    writer_->write(msg, "chatter", "example_interfaces/msg/String", time_stamp);
+    writer_->write(msg, "chatter", "std_msgs/msg/String", time_stamp);
   }
 
-  rclcpp::Subscription<example_interfaces::msg::String>::SharedPtr subscription_;
+  rclcpp::Subscription<std_msgs::msg::String>::SharedPtr subscription_;
   std::unique_ptr<rosbag2_cpp::Writer> writer_;
 };
 

From 6b276b10407a7a5f047afeec6b898ceddb286e5f Mon Sep 17 00:00:00 2001
From: Sangtaek Lee <sangteak601@gmail.com>
Date: Wed, 6 Mar 2024 06:35:01 +0000
Subject: [PATCH 11/19] update style after running tests

Signed-off-by: Sangtaek Lee <sangteak601@gmail.com>
---
 .../src/simple_bag_player.cpp                 | 80 +++++++++++--------
 .../rosbag2_examples_py/simple_bag_player.py  |  2 +-
 2 files changed, 48 insertions(+), 34 deletions(-)

diff --git a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp
index 124c005853..522059bfb6 100644
--- a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp
+++ b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp
@@ -1,5 +1,18 @@
+// Copyright 2024 Open Source Robotics Foundation
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 #include <chrono>
-#include <functional>
 #include <iostream>
 #include <memory>
 #include <string>
@@ -13,46 +26,47 @@ using namespace std::chrono_literals;
 
 class SimpleBagPlayer : public rclcpp::Node
 {
-  public:
-    SimpleBagPlayer(const std::string & bag_filename)
-    : Node("playback_node")
-    {
-      publisher_ = this->create_publisher<std_msgs::msg::String>("chatter", 10);
-
-      timer_ = this->create_wall_timer(100ms,
-          [this](){return this->timer_callback();}
-      );
-
-      reader_.open(bag_filename);
-    }
+public:
+  explicit SimpleBagPlayer(const std::string & bag_filename)
+  : Node("playback_node")
+  {
+    publisher_ = this->create_publisher<std_msgs::msg::String>("chatter", 10);
+
+    timer_ = this->create_wall_timer(
+      100ms,
+      [this](){return this->timer_callback();}
+    );
+
+    reader_.open(bag_filename);
+  }
 
-  private:
-    void timer_callback()
-    {
-      while (reader_.has_next()) {
-        rosbag2_storage::SerializedBagMessageSharedPtr msg = reader_.read_next();
+private:
+  void timer_callback()
+  {
+    while (reader_.has_next()) {
+      rosbag2_storage::SerializedBagMessageSharedPtr msg = reader_.read_next();
 
-        if (msg->topic_name != "chatter") {
-          continue;
-        }
+      if (msg->topic_name != "chatter") {
+        continue;
+      }
 
-        rclcpp::SerializedMessage serialized_msg(*msg->serialized_data);
-        std_msgs::msg::String::SharedPtr ros_msg = std::make_shared<std_msgs::msg::String>();
+      rclcpp::SerializedMessage serialized_msg(*msg->serialized_data);
+      std_msgs::msg::String::SharedPtr ros_msg = std::make_shared<std_msgs::msg::String>();
 
-        serialization_.deserialize_message(&serialized_msg, ros_msg.get());
+      serialization_.deserialize_message(&serialized_msg, ros_msg.get());
 
-        publisher_->publish(*ros_msg);
-        std::cout << ros_msg->data << "\n";
+      publisher_->publish(*ros_msg);
+      std::cout << ros_msg->data << "\n";
 
-        break;
-      }
+      break;
     }
+  }
 
-    rclcpp::TimerBase::SharedPtr timer_;
-    rclcpp::Publisher<std_msgs::msg::String>::SharedPtr publisher_;
+  rclcpp::TimerBase::SharedPtr timer_;
+  rclcpp::Publisher<std_msgs::msg::String>::SharedPtr publisher_;
 
-    rclcpp::Serialization<std_msgs::msg::String> serialization_;
-    rosbag2_cpp::Reader reader_;
+  rclcpp::Serialization<std_msgs::msg::String> serialization_;
+  rosbag2_cpp::Reader reader_;
 };
 
 int main(int argc, char ** argv)
@@ -67,4 +81,4 @@ int main(int argc, char ** argv)
   rclcpp::shutdown();
 
   return 0;
-}
\ No newline at end of file
+}
diff --git a/rosbag2_examples/rosbag2_examples_py/rosbag2_examples_py/simple_bag_player.py b/rosbag2_examples/rosbag2_examples_py/rosbag2_examples_py/simple_bag_player.py
index da897e1d69..e09da9e333 100644
--- a/rosbag2_examples/rosbag2_examples_py/rosbag2_examples_py/simple_bag_player.py
+++ b/rosbag2_examples/rosbag2_examples_py/rosbag2_examples_py/simple_bag_player.py
@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import sys
+
 import rclpy
 from rclpy.node import Node
 from rclpy.serialization import deserialize_message
@@ -43,7 +44,6 @@ def timer_callback(self):
             self.get_logger().info(ros_msg.data)
 
 
-
 def main(args=None):
     rclpy.init(args=args)
     sbr = SimpleBagPlayer(sys.argv[1])

From c2e071649eaf6b516514d4ac88514867cf48fbb8 Mon Sep 17 00:00:00 2001
From: Sangtaek Lee <sangteak601@gmail.com>
Date: Wed, 6 Mar 2024 20:36:04 +0000
Subject: [PATCH 12/19] reformatting

Signed-off-by: Sangtaek Lee <sangteak601@gmail.com>
---
 rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp
index 522059bfb6..0b06d52340 100644
--- a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp
+++ b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp
@@ -34,7 +34,7 @@ class SimpleBagPlayer : public rclcpp::Node
 
     timer_ = this->create_wall_timer(
       100ms,
-      [this](){return this->timer_callback();}
+      [this]() {return this->timer_callback();}
     );
 
     reader_.open(bag_filename);

From 6cfd64514749386b78a46b1752aeec089345212a Mon Sep 17 00:00:00 2001
From: Sangtaek Lee <sangteak601@gmail.com>
Date: Sun, 10 Mar 2024 11:35:56 +0000
Subject: [PATCH 13/19] add comment, rename node

Signed-off-by: Sangtaek Lee <sangteak601@gmail.com>
---
 .../rosbag2_examples_cpp/src/simple_bag_player.cpp             | 3 ++-
 .../rosbag2_examples_py/simple_bag_player.py                   | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp
index 0b06d52340..0959f1bb42 100644
--- a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp
+++ b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp
@@ -28,10 +28,11 @@ class SimpleBagPlayer : public rclcpp::Node
 {
 public:
   explicit SimpleBagPlayer(const std::string & bag_filename)
-  : Node("playback_node")
+  : Node("simple_bag_player")
   {
     publisher_ = this->create_publisher<std_msgs::msg::String>("chatter", 10);
 
+    // ignore timestamp and publish at a fixed rate (10 Hz).
     timer_ = this->create_wall_timer(
       100ms,
       [this]() {return this->timer_callback();}
diff --git a/rosbag2_examples/rosbag2_examples_py/rosbag2_examples_py/simple_bag_player.py b/rosbag2_examples/rosbag2_examples_py/rosbag2_examples_py/simple_bag_player.py
index e09da9e333..46a9ba80c0 100644
--- a/rosbag2_examples/rosbag2_examples_py/rosbag2_examples_py/simple_bag_player.py
+++ b/rosbag2_examples/rosbag2_examples_py/rosbag2_examples_py/simple_bag_player.py
@@ -1,4 +1,4 @@
-# Copyright 2023 Open Source Robotics Foundation, Inc.
+# Copyright 2024 Open Source Robotics Foundation, Inc.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -32,6 +32,7 @@ def __init__(self, bag_filename):
         self.reader.open(storage_options, converter_options)
 
         self.publisher = self.create_publisher(String, 'chatter', 10)
+        # ignore timestamp and publish at a fixed rate (10 Hz).
         self.timer = self.create_timer(0.1, self.timer_callback)
 
     def timer_callback(self):

From 1f53c6afb5dc911719fb1b7dc29728e073751fe3 Mon Sep 17 00:00:00 2001
From: Sangtaek Lee <sangteak601@gmail.com>
Date: Sat, 16 Mar 2024 16:53:53 +0000
Subject: [PATCH 14/19] divide examples into two cases: with and without
 deserialisation

Signed-off-by: Sangtaek Lee <sangteak601@gmail.com>
---
 .../src/simple_bag_player.cpp                 | 23 +++++++++++++------
 .../rosbag2_examples_py/simple_bag_player.py  | 12 +++++++---
 2 files changed, 25 insertions(+), 10 deletions(-)

diff --git a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp
index 0959f1bb42..6cd00abf52 100644
--- a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp
+++ b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp
@@ -51,13 +51,20 @@ class SimpleBagPlayer : public rclcpp::Node
         continue;
       }
 
-      rclcpp::SerializedMessage serialized_msg(*msg->serialized_data);
-      std_msgs::msg::String::SharedPtr ros_msg = std::make_shared<std_msgs::msg::String>();
-
-      serialization_.deserialize_message(&serialized_msg, ros_msg.get());
-
-      publisher_->publish(*ros_msg);
-      std::cout << ros_msg->data << "\n";
+      if (message_needs_to_be_edit_before_send_)
+      {
+        rclcpp::SerializedMessage serialized_msg(*msg->serialized_data);
+        std_msgs::msg::String::SharedPtr ros_msg = std::make_shared<std_msgs::msg::String>();
+
+        serialization_.deserialize_message(&serialized_msg, ros_msg.get());
+        ros_msg->data += "[edited]";
+        publisher_->publish(*ros_msg);
+        std::cout << ros_msg->data << "\n";
+      }
+      else
+      {
+        publisher_->publish(*msg->serialized_data);
+      }
 
       break;
     }
@@ -68,6 +75,8 @@ class SimpleBagPlayer : public rclcpp::Node
 
   rclcpp::Serialization<std_msgs::msg::String> serialization_;
   rosbag2_cpp::Reader reader_;
+
+  bool message_needs_to_be_edit_before_send_ {true};
 };
 
 int main(int argc, char ** argv)
diff --git a/rosbag2_examples/rosbag2_examples_py/rosbag2_examples_py/simple_bag_player.py b/rosbag2_examples/rosbag2_examples_py/rosbag2_examples_py/simple_bag_player.py
index 46a9ba80c0..d4bac76bdc 100644
--- a/rosbag2_examples/rosbag2_examples_py/rosbag2_examples_py/simple_bag_player.py
+++ b/rosbag2_examples/rosbag2_examples_py/rosbag2_examples_py/simple_bag_player.py
@@ -34,15 +34,21 @@ def __init__(self, bag_filename):
         self.publisher = self.create_publisher(String, 'chatter', 10)
         # ignore timestamp and publish at a fixed rate (10 Hz).
         self.timer = self.create_timer(0.1, self.timer_callback)
+        self.message_needs_to_be_edit_before_send_ = True
 
     def timer_callback(self):
         while self.reader.has_next():
             msg = self.reader.read_next()
             if msg[0] != 'chatter':
                 continue
-            ros_msg = deserialize_message(msg[1], String)
-            self.publisher.publish(ros_msg)
-            self.get_logger().info(ros_msg.data)
+
+            if self.message_needs_to_be_edit_before_send_:
+                ros_msg = deserialize_message(msg[1], String)
+                ros_msg.data += '[edited]'
+                self.publisher.publish(ros_msg)
+                self.get_logger().info(ros_msg.data)
+            else:
+                self.publisher.publish(msg[1])
 
 
 def main(args=None):

From 77eb62ad45602271d37abfc29edc20f40cbcf691 Mon Sep 17 00:00:00 2001
From: Sangtaek Lee <sangteak601@gmail.com>
Date: Wed, 20 Mar 2024 20:48:16 +0000
Subject: [PATCH 15/19] fix test failure

Signed-off-by: Sangtaek Lee <sangteak601@gmail.com>
---
 .../rosbag2_examples_cpp/src/simple_bag_player.cpp         | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp
index 6cd00abf52..13d84c9b38 100644
--- a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp
+++ b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp
@@ -51,8 +51,7 @@ class SimpleBagPlayer : public rclcpp::Node
         continue;
       }
 
-      if (message_needs_to_be_edit_before_send_)
-      {
+      if (message_needs_to_be_edit_before_send_) {
         rclcpp::SerializedMessage serialized_msg(*msg->serialized_data);
         std_msgs::msg::String::SharedPtr ros_msg = std::make_shared<std_msgs::msg::String>();
 
@@ -60,9 +59,7 @@ class SimpleBagPlayer : public rclcpp::Node
         ros_msg->data += "[edited]";
         publisher_->publish(*ros_msg);
         std::cout << ros_msg->data << "\n";
-      }
-      else
-      {
+      } else {
         publisher_->publish(*msg->serialized_data);
       }
 

From 2ea728208cd8c42b3a80f33343c647eff61d2ed0 Mon Sep 17 00:00:00 2001
From: Sangtaek Lee <sangteak601@gmail.com>
Date: Fri, 22 Mar 2024 19:26:45 +0000
Subject: [PATCH 16/19] divide recoder example into two cases: with and without
 serialisation

Signed-off-by: Sangtaek Lee <sangteak601@gmail.com>
---
 .../src/simple_bag_recorder.cpp               | 22 +++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_recorder.cpp b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_recorder.cpp
index b2910ab0c4..f691d8a5ad 100644
--- a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_recorder.cpp
+++ b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_recorder.cpp
@@ -31,8 +31,13 @@ class SimpleBagRecorder : public rclcpp::Node
 
     writer_->open("my_bag");
 
-    subscription_ = create_subscription<std_msgs::msg::String>(
-      "chatter", 10, std::bind(&SimpleBagRecorder::topic_callback, this, _1));
+    if (message_needs_to_be_edit_before_write_) {
+      subscription_ = create_subscription<std_msgs::msg::String>(
+        "chatter", 10, std::bind(&SimpleBagRecorder::topic_edit_callback, this, _1));
+    } else {
+      subscription_ = create_subscription<std_msgs::msg::String>(
+        "chatter", 10, std::bind(&SimpleBagRecorder::topic_callback, this, _1));
+    }
   }
 
 private:
@@ -42,8 +47,21 @@ class SimpleBagRecorder : public rclcpp::Node
     writer_->write(msg, "chatter", "std_msgs/msg/String", time_stamp);
   }
 
+  void topic_edit_callback(std_msgs::msg::String::UniquePtr msg) const
+  {
+    rclcpp::Time time_stamp = this->now();
+    msg->data += "[edited]";
+    rclcpp::SerializedMessage serialized_msg;
+    serialization_.serialize_message(msg.get(), &serialized_msg);
+    writer_->write(serialized_msg, "chatter", "std_msgs/msg/String", time_stamp);
+  }
+
+
   rclcpp::Subscription<std_msgs::msg::String>::SharedPtr subscription_;
+  rclcpp::Serialization<std_msgs::msg::String> serialization_;
   std::unique_ptr<rosbag2_cpp::Writer> writer_;
+
+  bool message_needs_to_be_edit_before_write_ {true};
 };
 
 int main(int argc, char * argv[])

From 0690d6abf28a57c50e78b28e010dc36a0a518894 Mon Sep 17 00:00:00 2001
From: Sangtaek Lee <sangteak601@gmail.com>
Date: Sun, 24 Mar 2024 09:22:31 +0000
Subject: [PATCH 17/19] Fix compile warning

Signed-off-by: Sangtaek Lee <sangteak601@gmail.com>
---
 .../rosbag2_examples_cpp/src/simple_bag_recorder.cpp          | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_recorder.cpp b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_recorder.cpp
index f691d8a5ad..2ccacbdba6 100644
--- a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_recorder.cpp
+++ b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_recorder.cpp
@@ -51,8 +51,8 @@ class SimpleBagRecorder : public rclcpp::Node
   {
     rclcpp::Time time_stamp = this->now();
     msg->data += "[edited]";
-    rclcpp::SerializedMessage serialized_msg;
-    serialization_.serialize_message(msg.get(), &serialized_msg);
+    auto serialized_msg = std::make_shared<rclcpp::SerializedMessage>();
+    serialization_.serialize_message(msg.get(), serialized_msg.get());
     writer_->write(serialized_msg, "chatter", "std_msgs/msg/String", time_stamp);
   }
 

From e172f3545b6638c597765dddf114db62a8585020 Mon Sep 17 00:00:00 2001
From: Sangtaek Lee <sangteak601@gmail.com>
Date: Mon, 1 Apr 2024 19:58:12 +0000
Subject: [PATCH 18/19] Add a parameter

Signed-off-by: Sangtaek Lee <sangteak601@gmail.com>
---
 .../rosbag2_examples_cpp/src/simple_bag_player.cpp       | 9 ++++++---
 .../rosbag2_examples_cpp/src/simple_bag_recorder.cpp     | 5 ++++-
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp
index 13d84c9b38..704a71fa84 100644
--- a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp
+++ b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_player.cpp
@@ -30,12 +30,15 @@ class SimpleBagPlayer : public rclcpp::Node
   explicit SimpleBagPlayer(const std::string & bag_filename)
   : Node("simple_bag_player")
   {
+    declare_parameter("edit", false);
+    message_needs_to_be_edit_before_send_ = get_parameter("edit").as_bool();
+
     publisher_ = this->create_publisher<std_msgs::msg::String>("chatter", 10);
 
     // ignore timestamp and publish at a fixed rate (10 Hz).
     timer_ = this->create_wall_timer(
       100ms,
-      [this]() {return this->timer_callback();}
+      [this]() {this->timer_callback();}
     );
 
     reader_.open(bag_filename);
@@ -73,12 +76,12 @@ class SimpleBagPlayer : public rclcpp::Node
   rclcpp::Serialization<std_msgs::msg::String> serialization_;
   rosbag2_cpp::Reader reader_;
 
-  bool message_needs_to_be_edit_before_send_ {true};
+  bool message_needs_to_be_edit_before_send_;
 };
 
 int main(int argc, char ** argv)
 {
-  if (argc != 2) {
+  if (argc < 2) {
     std::cerr << "Usage: " << argv[0] << " <bag>" << std::endl;
     return 1;
   }
diff --git a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_recorder.cpp b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_recorder.cpp
index 2ccacbdba6..2463df9734 100644
--- a/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_recorder.cpp
+++ b/rosbag2_examples/rosbag2_examples_cpp/src/simple_bag_recorder.cpp
@@ -27,6 +27,9 @@ class SimpleBagRecorder : public rclcpp::Node
   SimpleBagRecorder()
   : Node("simple_bag_recorder")
   {
+    declare_parameter("edit", false);
+    message_needs_to_be_edit_before_write_ = get_parameter("edit").as_bool();
+
     writer_ = std::make_unique<rosbag2_cpp::Writer>();
 
     writer_->open("my_bag");
@@ -61,7 +64,7 @@ class SimpleBagRecorder : public rclcpp::Node
   rclcpp::Serialization<std_msgs::msg::String> serialization_;
   std::unique_ptr<rosbag2_cpp::Writer> writer_;
 
-  bool message_needs_to_be_edit_before_write_ {true};
+  bool message_needs_to_be_edit_before_write_;
 };
 
 int main(int argc, char * argv[])

From 828237141de42b757037512167cd25c5d2ba108d Mon Sep 17 00:00:00 2001
From: Sangtaek Lee <sangteak601@gmail.com>
Date: Mon, 1 Apr 2024 20:02:36 +0000
Subject: [PATCH 19/19] add a parameter in python examples

Signed-off-by: Sangtaek Lee <sangteak601@gmail.com>
---
 .../rosbag2_examples_py/simple_bag_player.py                   | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/rosbag2_examples/rosbag2_examples_py/rosbag2_examples_py/simple_bag_player.py b/rosbag2_examples/rosbag2_examples_py/rosbag2_examples_py/simple_bag_player.py
index d4bac76bdc..09b8146ed7 100644
--- a/rosbag2_examples/rosbag2_examples_py/rosbag2_examples_py/simple_bag_player.py
+++ b/rosbag2_examples/rosbag2_examples_py/rosbag2_examples_py/simple_bag_player.py
@@ -34,7 +34,8 @@ def __init__(self, bag_filename):
         self.publisher = self.create_publisher(String, 'chatter', 10)
         # ignore timestamp and publish at a fixed rate (10 Hz).
         self.timer = self.create_timer(0.1, self.timer_callback)
-        self.message_needs_to_be_edit_before_send_ = True
+        self.declare_parameter("edit", False)
+        self.message_needs_to_be_edit_before_send_ = self.get_parameter("edit").get_parameter_value().bool_value
 
     def timer_callback(self):
         while self.reader.has_next():