feat: Audio Visualizer for Windows/Linux. (#739)

close #734

- [x] Windows
- [x] Linux


![image](https://github.com/user-attachments/assets/e1655d24-9575-4f91-9a55-da1171a13ccc)

Author: cloudwebrtc

example/linux/CMakeLists.txt

@@ -4,7 +4,7 @@ project(runner LANGUAGES CXX)
 
 # The name of the executable created for the application. Change this to change
 # the on-disk name of your application.
-set(BINARY_NAME "example")
+set(BINARY_NAME "livekit_client_example")
 # The unique GTK application identifier for this application. See:
 # https://wiki.gnome.org/HowDoI/ChooseApplicationID
 set(APPLICATION_ID "io.livekit.example.example")

example/linux/my_application.cc

@@ -40,11 +40,11 @@ static void my_application_activate(GApplication* application) {
   if (use_header_bar) {
     GtkHeaderBar* header_bar = GTK_HEADER_BAR(gtk_header_bar_new());
     gtk_widget_show(GTK_WIDGET(header_bar));
-    gtk_header_bar_set_title(header_bar, "example");
+    gtk_header_bar_set_title(header_bar, "livekit_client_example");
     gtk_header_bar_set_show_close_button(header_bar, TRUE);
     gtk_window_set_titlebar(window, GTK_WIDGET(header_bar));
   } else {
-    gtk_window_set_title(window, "example");
+    gtk_window_set_title(window, "livekit_client_example");
   }
 
   gtk_window_set_default_size(window, 1280, 720);

example/windows/flutter/CMakeLists.txt

@@ -9,6 +9,11 @@ include(${EPHEMERAL_DIR}/generated_config.cmake)
 # https://github.com/flutter/flutter/issues/57146.
 set(WRAPPER_ROOT "${EPHEMERAL_DIR}/cpp_client_wrapper")
 
+# Set fallback configurations for older versions of the flutter tool.
+if (NOT DEFINED FLUTTER_TARGET_PLATFORM)
+  set(FLUTTER_TARGET_PLATFORM "windows-x64")
+endif()
+
 # === Flutter Library ===
 set(FLUTTER_LIBRARY "${EPHEMERAL_DIR}/flutter_windows.dll")
 
@@ -91,7 +96,7 @@ add_custom_command(
   COMMAND ${CMAKE_COMMAND} -E env
     ${FLUTTER_TOOL_ENVIRONMENT}
     "${FLUTTER_ROOT}/packages/flutter_tools/bin/tool_backend.bat"
-      windows-x64 $<CONFIG>
+      ${FLUTTER_TARGET_PLATFORM} $<CONFIG>
   VERBATIM
 )
 add_custom_target(flutter_assemble DEPENDS

example/windows/runner/Runner.rc

@@ -60,14 +60,14 @@ IDI_APP_ICON            ICON                    "resources\\app_icon.ico"
 // Version
 //
 
-#ifdef FLUTTER_BUILD_NUMBER
-#define VERSION_AS_NUMBER FLUTTER_BUILD_NUMBER
+#if defined(FLUTTER_VERSION_MAJOR) && defined(FLUTTER_VERSION_MINOR) && defined(FLUTTER_VERSION_PATCH) && defined(FLUTTER_VERSION_BUILD)
+#define VERSION_AS_NUMBER FLUTTER_VERSION_MAJOR,FLUTTER_VERSION_MINOR,FLUTTER_VERSION_PATCH,FLUTTER_VERSION_BUILD
 #else
-#define VERSION_AS_NUMBER 1,0,0
+#define VERSION_AS_NUMBER 1,0,0,0
 #endif
 
-#ifdef FLUTTER_BUILD_NAME
-#define VERSION_AS_STRING #FLUTTER_BUILD_NAME
+#if defined(FLUTTER_VERSION)
+#define VERSION_AS_STRING FLUTTER_VERSION
 #else
 #define VERSION_AS_STRING "1.0.0"
 #endif

linux/CMakeLists.txt

@@ -0,0 +1,113 @@
+# The Flutter tooling requires that developers have CMake 3.10 or later
+# installed. You should not increase this version, as doing so will cause
+# the plugin to fail to compile for some customers of the plugin.
+cmake_minimum_required(VERSION 3.10)
+
+# Project-level configuration.
+set(PROJECT_NAME "livekit")
+project(${PROJECT_NAME} LANGUAGES CXX C)
+
+# This value is used when generating builds using this plugin, so it must
+# not be changed.
+set(PLUGIN_NAME "livekit_client_plugin")
+
+
+add_definitions(-D_USE_MATH_DEFINES)
+add_definitions(-DRTC_DESKTOP_DEVICE)
+
+include_directories(
+  "${CMAKE_CURRENT_SOURCE_DIR}"
+  "${CMAKE_CURRENT_SOURCE_DIR}/flutter/include"
+  "${CMAKE_CURRENT_SOURCE_DIR}/../shared_cpp"
+)
+
+# Any new source files that you add to the plugin should be added here.
+list(APPEND PLUGIN_SOURCES
+  "livekit_plugin.cpp"
+  "task_runner_linux.cc"
+  "../shared_cpp/fft_processor.cpp"
+  "../shared_cpp/audio_visualizer.cpp"
+  "../shared_cpp/pffft.c"
+  "flutter/core_implementations.cc"
+  "flutter/standard_codec.cc"
+  "flutter/plugin_registrar.cc"
+)
+
+#target_compile_options(${PLUGIN_NAME} PRIVATE -Wno-deprecated-declarations)
+
+# Define the plugin library target. Its name must not be changed (see comment
+# on PLUGIN_NAME above).
+add_library(${PLUGIN_NAME} SHARED
+  ${PLUGIN_SOURCES}
+)
+
+# Apply a standard set of build settings that are configured in the
+# application-level CMakeLists.txt. This can be removed for plugins that want
+# full control over build settings.
+apply_standard_settings(${PLUGIN_NAME})
+
+# Symbols are hidden by default to reduce the chance of accidental conflicts
+# between plugins. This should not be removed; any symbols that should be
+# exported should be explicitly exported with the FLUTTER_PLUGIN_EXPORT macro.
+set_target_properties(${PLUGIN_NAME} PROPERTIES
+  CXX_VISIBILITY_PRESET hidden)
+target_compile_definitions(${PLUGIN_NAME} PRIVATE FLUTTER_PLUGIN_IMPL)
+
+# Source include directories and library dependencies. Add any plugin-specific
+# dependencies here.
+target_include_directories(${PLUGIN_NAME} INTERFACE
+  "${CMAKE_CURRENT_SOURCE_DIR}/include")
+target_link_libraries(${PLUGIN_NAME} PRIVATE flutter flutter_webrtc_plugin)
+target_link_libraries(${PLUGIN_NAME} PRIVATE PkgConfig::GTK)
+
+# List of absolute paths to libraries that should be bundled with the plugin.
+# This list could contain prebuilt libraries, or libraries created by an
+# external build triggered from this build file.
+set(livekit_bundled_libraries
+  ""
+  PARENT_SCOPE
+)
+
+# === Tests ===
+# These unit tests can be run from a terminal after building the example.
+
+# Only enable test builds when building the example (which sets this variable)
+# so that plugin clients aren't building the tests.
+if (${include_${PROJECT_NAME}_tests})
+if(${CMAKE_VERSION} VERSION_LESS "3.11.0")
+message("Unit tests require CMake 3.11.0 or later")
+else()
+set(TEST_RUNNER "${PROJECT_NAME}_test")
+enable_testing()
+
+# Add the Google Test dependency.
+include(FetchContent)
+FetchContent_Declare(
+  googletest
+  URL https://github.com/google/googletest/archive/release-1.11.0.zip
+)
+# Prevent overriding the parent project's compiler/linker settings
+set(gtest_force_shared_crt ON CACHE BOOL "" FORCE)
+# Disable install commands for gtest so it doesn't end up in the bundle.
+set(INSTALL_GTEST OFF CACHE BOOL "Disable installation of googletest" FORCE)
+
+FetchContent_MakeAvailable(googletest)
+
+# The plugin's exported API is not very useful for unit testing, so build the
+# sources directly into the test binary rather than using the shared library.
+add_executable(${TEST_RUNNER}
+  test/livekit_plugin_test.cc
+  ${PLUGIN_SOURCES}
+)
+apply_standard_settings(${TEST_RUNNER})
+target_include_directories(${TEST_RUNNER} PRIVATE "${CMAKE_CURRENT_SOURCE_DIR}")
+target_link_libraries(${TEST_RUNNER} PRIVATE flutter)
+target_link_libraries(${TEST_RUNNER} PRIVATE PkgConfig::GTK)
+target_link_libraries(${TEST_RUNNER} PRIVATE gtest_main gmock)
+
+# Enable automatic test discovery.
+include(GoogleTest)
+gtest_discover_tests(${TEST_RUNNER})
+
+endif()  # CMake version check
+endif()  # include_${PROJECT_NAME}_tests

linux/flutter/binary_messenger_impl.h

@@ -0,0 +1,50 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef FLUTTER_SHELL_PLATFORM_COMMON_CLIENT_WRAPPER_BINARY_MESSENGER_IMPL_H_
+#define FLUTTER_SHELL_PLATFORM_COMMON_CLIENT_WRAPPER_BINARY_MESSENGER_IMPL_H_
+
+#include <flutter_linux/flutter_linux.h>
+
+#include <map>
+#include <string>
+
+#include "include/flutter/binary_messenger.h"
+
+namespace flutter {
+
+// Wrapper around a FlutterDesktopMessengerRef that implements the
+// BinaryMessenger API.
+class BinaryMessengerImpl : public BinaryMessenger {
+ public:
+  explicit BinaryMessengerImpl(FlBinaryMessenger* core_messenger);
+
+  virtual ~BinaryMessengerImpl();
+
+  // Prevent copying.
+  BinaryMessengerImpl(BinaryMessengerImpl const&) = delete;
+  BinaryMessengerImpl& operator=(BinaryMessengerImpl const&) = delete;
+
+  // |flutter::BinaryMessenger|
+  void Send(const std::string& channel,
+            const uint8_t* message,
+            size_t message_size,
+            BinaryReply reply) const override;
+
+  // |flutter::BinaryMessenger|
+  void SetMessageHandler(const std::string& channel,
+                         BinaryMessageHandler handler) override;
+
+ private:
+  // Handle for interacting with the C API.
+  FlBinaryMessenger* messenger_;
+
+  // A map from channel names to the BinaryMessageHandler that should be called
+  // for incoming messages on that channel.
+  std::map<std::string, BinaryMessageHandler> handlers_;
+};
+
+}  // namespace flutter
+
+#endif  // FLUTTER_SHELL_PLATFORM_COMMON_CLIENT_WRAPPER_BINARY_MESSENGER_IMPL_H_

linux/flutter/byte_buffer_streams.h

@@ -0,0 +1,102 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef FLUTTER_SHELL_PLATFORM_COMMON_CLIENT_WRAPPER_BYTE_BUFFER_STREAMS_H_
+#define FLUTTER_SHELL_PLATFORM_COMMON_CLIENT_WRAPPER_BYTE_BUFFER_STREAMS_H_
+
+#include <cassert>
+#include <cstdint>
+#include <cstring>
+#include <iostream>
+#include <vector>
+
+#include "include/flutter/byte_streams.h"
+
+namespace flutter {
+
+// Implementation of ByteStreamReader base on a byte array.
+class ByteBufferStreamReader : public ByteStreamReader {
+ public:
+  // Createa a reader reading from |bytes|, which must have a length of |size|.
+  // |bytes| must remain valid for the lifetime of this object.
+  explicit ByteBufferStreamReader(const uint8_t* bytes, size_t size)
+      : bytes_(bytes), size_(size) {}
+
+  virtual ~ByteBufferStreamReader() = default;
+
+  // |ByteStreamReader|
+  uint8_t ReadByte() override {
+    if (location_ >= size_) {
+      std::cerr << "Invalid read in StandardCodecByteStreamReader" << std::endl;
+      return 0;
+    }
+    return bytes_[location_++];
+  }
+
+  // |ByteStreamReader|
+  void ReadBytes(uint8_t* buffer, size_t length) override {
+    if (location_ + length > size_) {
+      std::cerr << "Invalid read in StandardCodecByteStreamReader" << std::endl;
+      return;
+    }
+    std::memcpy(buffer, &bytes_[location_], length);
+    location_ += length;
+  }
+
+  // |ByteStreamReader|
+  void ReadAlignment(uint8_t alignment) override {
+    uint8_t mod = location_ % alignment;
+    if (mod) {
+      location_ += alignment - mod;
+    }
+  }
+
+ private:
+  // The buffer to read from.
+  const uint8_t* bytes_;
+  // The total size of the buffer.
+  size_t size_;
+  // The current read location.
+  size_t location_ = 0;
+};
+
+// Implementation of ByteStreamWriter based on a byte array.
+class ByteBufferStreamWriter : public ByteStreamWriter {
+ public:
+  // Creates a writer that writes into |buffer|.
+  // |buffer| must remain valid for the lifetime of this object.
+  explicit ByteBufferStreamWriter(std::vector<uint8_t>* buffer)
+      : bytes_(buffer) {
+    assert(buffer);
+  }
+
+  virtual ~ByteBufferStreamWriter() = default;
+
+  // |ByteStreamWriter|
+  void WriteByte(uint8_t byte) { bytes_->push_back(byte); }
+
+  // |ByteStreamWriter|
+  void WriteBytes(const uint8_t* bytes, size_t length) {
+    assert(length > 0);
+    bytes_->insert(bytes_->end(), bytes, bytes + length);
+  }
+
+  // |ByteStreamWriter|
+  void WriteAlignment(uint8_t alignment) {
+    uint8_t mod = bytes_->size() % alignment;
+    if (mod) {
+      for (int i = 0; i < alignment - mod; ++i) {
+        WriteByte(0);
+      }
+    }
+  }
+
+ private:
+  // The buffer to write to.
+  std::vector<uint8_t>* bytes_;
+};
+
+}  // namespace flutter
+
+#endif  // FLUTTER_SHELL_PLATFORM_COMMON_CLIENT_WRAPPER_BYTE_BUFFER_STREAMS_H_