为什么cmake使用find_package会找不到SHMPOOLTOOL_INCLUDE_DIR这样的环境变量

CMake使用find_package查找软件包时，需要软件包提供一个CMake模块，该模块包含了软件包的信息和变量。如果SHMPOOLTOOL_INCLUDE_DIR没有被定义或者没有被包含在相关的CMake模块中，那么CMake将无法找到该变量，从而无法找到所需的软件包。因此，确保SHMPOOLTOOL_INCLUDE_DIR被正确定义并且包含在相关的CMake模块中非常重要。

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# toplevel CMakeLists.txt for a catkin workspace # catkin/cmake/toplevel.cmake cmake_minimum_required(VERSION 3.0.2) project(Project) set(CATKIN_TOPLEVEL TRUE) # search for catkin within the workspace set(_cmd "catkin_find_pkg" "catkin" "${CMAKE_SOURCE_DIR}") execute_process(COMMAND ${_cmd} RESULT_VARIABLE _res OUTPUT_VARIABLE _out ERROR_VARIABLE _err OUTPUT_STRIP_TRAILING_WHITESPACE ERROR_STRIP_TRAILING_WHITESPACE ) if(NOT _res EQUAL 0 AND NOT _res EQUAL 2) # searching fot catkin resulted in an error string(REPLACE ";" " " _cmd_str "${_cmd}") message(FATAL_ERROR "Search for 'catkin' in workspace failed (${_cmd_str}): ${_err}") endif() # include catkin from workspace or via find_package() if(_res EQUAL 0) set(catkin_EXTRAS_DIR "${CMAKE_SOURCE_DIR}/${_out}/cmake") # include all.cmake without add_subdirectory to let it operate in same scope include(${catkin_EXTRAS_DIR}/all.cmake NO_POLICY_SCOPE) add_subdirectory("${_out}") else() # use either CMAKE_PREFIX_PATH explicitly passed to CMake as a command line argument # or CMAKE_PREFIX_PATH from the environment if(NOT DEFINED CMAKE_PREFIX_PATH) if(NOT "$ENV{CMAKE_PREFIX_PATH}" STREQUAL "") if(NOT WIN32) string(REPLACE ":" ";" CMAKE_PREFIX_PATH $ENV{CMAKE_PREFIX_PATH}) else() set(CMAKE_PREFIX_PATH $ENV{CMAKE_PREFIX_PATH}) endif() endif() endif() # list of catkin workspaces set(catkin_search_path "") foreach(path ${CMAKE_PREFIX_PATH}) if(EXISTS "${path}/.catkin") list(FIND catkin_search_path ${path} _index) if(_index EQUAL -1) list(APPEND catkin_search_path ${path}) endif() endif() endforeach() # search for catkin in all workspaces set(CATKIN_TOPLEVEL_FIND_PACKAGE TRUE) find_package(catkin QUIET NO_POLICY_SCOPE PATHS ${catkin_search_path} NO_DEFAULT_PATH NO_CMAKE_FIND_ROOT_PATH) unset(CATKIN_TOPLEVEL_FIND_PACKAGE) if(NOT catkin_FOUND) message(FATAL_ERROR "find_package(catkin) failed. catkin was neither found in the workspace nor in the CMAKE_PREFIX_PATH. One reason may be that no ROS setup.sh was sourced before.") endif() endif() catkin_workspace()目标名称是什么

根据您提供的 CMakeLists.txt 文件，您的项目的目标名称是 "Project"。在项目的顶层 CMakeLists.txt 文件中，使用 `project(Project)` 命令设置了项目的名称为 "Project"。

请注意，这里的 "Project" 只是示例名称，您可以根据自己的项目需求将其替换为实际的目标名称。如果您在其他地方使用了 `add_executable()` 或 `add_library()` 函数来创建其他目标，您可能需要查找这些函数并提取相应的目标名称。

如果您还有其他问题，请随时提问。

include_directories(/path/to/ffmpeg/include) link_directories(/path/to/ffmpeg/lib)添加在# toplevel CMakeLists.txt for a catkin workspace # catkin/cmake/toplevel.cmake cmake_minimum_required(VERSION 3.0.2) project(Project) set(CATKIN_TOPLEVEL TRUE) # search for catkin within the workspace set(_cmd "catkin_find_pkg" "catkin" "${CMAKE_SOURCE_DIR}") execute_process(COMMAND ${_cmd} RESULT_VARIABLE _res OUTPUT_VARIABLE _out ERROR_VARIABLE _err OUTPUT_STRIP_TRAILING_WHITESPACE ERROR_STRIP_TRAILING_WHITESPACE ) if(NOT _res EQUAL 0 AND NOT _res EQUAL 2) # searching fot catkin resulted in an error string(REPLACE ";" " " _cmd_str "${_cmd}") message(FATAL_ERROR "Search for 'catkin' in workspace failed (${_cmd_str}): ${_err}") endif() # include catkin from workspace or via find_package() if(_res EQUAL 0) set(catkin_EXTRAS_DIR "${CMAKE_SOURCE_DIR}/${_out}/cmake") # include all.cmake without add_subdirectory to let it operate in same scope include(${catkin_EXTRAS_DIR}/all.cmake NO_POLICY_SCOPE) add_subdirectory("${_out}") target_link_libraries(v4l_driver avcodec avformat swscale) else() # use either CMAKE_PREFIX_PATH explicitly passed to CMake as a command line argument # or CMAKE_PREFIX_PATH from the environment if(NOT DEFINED CMAKE_PREFIX_PATH) if(NOT "$ENV{CMAKE_PREFIX_PATH}" STREQUAL "") if(NOT WIN32) string(REPLACE ":" ";" CMAKE_PREFIX_PATH $ENV{CMAKE_PREFIX_PATH}) else() set(CMAKE_PREFIX_PATH $ENV{CMAKE_PREFIX_PATH}) endif() endif() endif() # list of catkin workspaces set(catkin_search_path "") foreach(path ${CMAKE_PREFIX_PATH}) if(EXISTS "${path}/.catkin") list(FIND catkin_search_path ${path} _index) if(_index EQUAL -1) list(APPEND catkin_search_path ${path}) endif() endif() endforeach() # search for catkin in all workspaces set(CATKIN_TOPLEVEL_FIND_PACKAGE TRUE) find_package(catkin QUIET NO_POLICY_SCOPE PATHS ${catkin_search_path} NO_DEFAULT_PATH NO_CMAKE_FIND_ROOT_PATH) unset(CATKIN_TOPLEVEL_FIND_PACKAGE) if(NOT catkin_FOUND) message(FATAL_ERROR "find_package(catkin) failed. catkin was neither found in the workspace nor in the CMAKE_PREFIX_PATH. One reason may be that no ROS setup.sh was sourced before.") endif() endif() catkin_workspace()哪

请将以下内容添加到 `toplevel.cmake` 文件中的 `if(_res EQUAL 0)` 分支中：

include_directories(/path/to/ffmpeg/include)
link_directories(/path/to/ffmpeg/lib)

其中 `/path/to/ffmpeg` 应替换为您实际的 FFmpeg 安装路径。

请注意，这些路径应该添加在 `target_link_libraries(v4l_driver avcodec avformat swscale)` 之前。确保在执行 `target_link_libraries` 命令之前添加这些路径，以便链接到正确的 FFmpeg 库。

完成后，重新构建您的项目，应该就能正确引用 FFmpeg 相关的库和头文件了。

如果您还有其他问题，请随时提问。