/root/catkin_uc/src/usb_cam/src/camera_driver.cpp: In destructor ‘virtual usb_cam::AbstractV4LUSBCam::~AbstractV4LUSBCam()’: /root/catkin_uc/src/usb_cam/src/camera_driver.cpp:236:5: error: ‘av_packet_free’ was not declared in this scope av_packet_free(&avpkt); ^~~~~~~~~~~~~~ /root/catkin_uc/src/usb_cam/src/camera_driver.cpp:236:5: note: suggested alternative: ‘av_packet_ref’ av_packet_free(&avpkt); ^~~~~~~~~~~~~~ av_packet_ref /root/catkin_uc/src/usb_cam/src/camera_driver.cpp: In static member function ‘static bool usb_cam::AbstractV4LUSBCam::init_decoder()’: /root/catkin_uc/src/usb_cam/src/camera_driver.cpp:376:13: error: ‘av_packet_alloc’ was not declared in this scope avpkt = av_packet_alloc(); ^~~~~~~~~~~~~~~ /root/catkin_uc/src/usb_cam/src/camera_driver.cpp:376:13: note: suggested alternative: ‘av_image_alloc’ avpkt = av_packet_alloc(); ^~~~~~~~~~~~~~~ av_image_alloc /root/catkin_uc/src/usb_cam/src/camera_driver.cpp: In static member function ‘static bool usb_cam::AbstractV4LUSBCam::decode_ffmpeg(const void*, int, usb_cam::camera_image_t*)’: /root/catkin_uc/src/usb_cam/src/camera_driver.cpp:776:8: error: ‘avcodec_send_packet’ was not declared in this scope if(avcodec_send_packet(avcodec_context, avpkt) < 0) ^~~~~~~~~~~~~~~~~~~ /root/catkin_uc/src/usb_cam/src/camera_driver.cpp:776:8: note: suggested alternative: ‘av_append_packet’ if(avcodec_send_packet(avcodec_context, avpkt) < 0) ^~~~~~~~~~~~~~~~~~~ av_append_packet /root/catkin_uc/src/usb_cam/src/camera_driver.cpp:789:9: error: ‘avcodec_receive_frame’ was not declared in this scope if (avcodec_receive_frame(avcodec_context, avframe_camera) < 0) ^~~~~~~~~~~~~~~~~~~~~ /root/catkin_uc/src/usb_cam/src/camera_driver.cpp:789:9: note: suggested alternative: ‘avcodec_free_frame’ if (avcodec_receive_frame(avcodec_context, avframe_camera) < 0) ^~~~~~~~~~~~~~~~~~~~~ avcodec_free_frame usb_cam/CMakeFiles/v4l_driver.dir/build.make:110: recipe for target 'usb_cam/CMakeFiles/v4l_driver.dir/src/camera_driver.cpp.o' failed make[2]: *** [usb_cam/CMakeFiles/v4l_driver.dir/src/camera_driver.cpp.o] Error 1 CMakeFiles/Makefile2:656: recipe for target 'usb_cam/CMakeFiles/v4l_driver.dir/all' failed make[1]: *** [usb_cam/CMakeFiles/v4l_driver.dir/all] Error 2 Makefile:140: recipe for target 'all' failed make: *** [all] Error 2 Invoking "make -j4 -l4" failed

根据错误信息，您的代码在以下几个地方使用了未声明的 FFmpeg 函数：

- av_packet_free()
- av_packet_alloc()
- avcodec_send_packet()
- avcodec_receive_frame()

这些错误提示表明您可能没有正确包含 FFmpeg 相关的头文件。请确保在 camera_driver.cpp 文件中包含正确的头文件。您可以尝试添加以下代码段到 camera_driver.cpp 文件的开头：

extern "C" {
#include <libavcodec/avcodec.h>
}

这将确保正确声明和包含 FFmpeg 的 avcodec 头文件。请确保将此代码段添加到其他头文件的上方。

另外，请确保已经正确安装了 FFmpeg 库，并且在 CMakeLists.txt 文件中添加了正确的链接库指令。您可以使用类似以下的代码将 FFmpeg 的库链接到您的目标上：

target_link_libraries(your_target_name avcodec avformat swscale)

请注意将 `your_target_name` 替换为您实际的目标名称。

如果问题仍然存在，请检查您的环境是否正确配置了 FFmpeg，并且确保您正在使用正确版本的 FFmpeg 库。

如果您还有其他问题，请随时提问。

相关问题

[ 12%] Building CXX object usb_cam/CMakeFiles/v4l_driver.dir/src/camera_driver.cpp.o /root/catkin_uc/src/usb_cam/src/camera_driver.cpp: In destructor ‘virtual usb_cam::AbstractV4LUSBCam::~AbstractV4LUSBCam()’: /root/catkin_uc/src/usb_cam/src/camera_driver.cpp:239:5: error: ‘av_packet_free’ was not declared in this scope av_packet_free(&avpkt); ^~~~~~~~~~~~~~ /root/catkin_uc/src/usb_cam/src/camera_driver.cpp:239:5: note: suggested alternative: ‘av_packet_ref’ av_packet_free(&avpkt); ^~~~~~~~~~~~~~ av_packet_ref /root/catkin_uc/src/usb_cam/src/camera_driver.cpp: In static member function ‘static bool usb_cam::AbstractV4LUSBCam::init_decoder()’: /root/catkin_uc/src/usb_cam/src/camera_driver.cpp:379:13: error: ‘av_packet_alloc’ was not declared in this scope avpkt = av_packet_alloc(); ^~~~~~~~~~~~~~~ /root/catkin_uc/src/usb_cam/src/camera_driver.cpp:379:13: note: suggested alternative: ‘av_image_alloc’ avpkt = av_packet_alloc(); ^~~~~~~~~~~~~~~ av_image_alloc /root/catkin_uc/src/usb_cam/src/camera_driver.cpp: In static member function ‘static bool usb_cam::AbstractV4LUSBCam::decode_ffmpeg(const void*, int, usb_cam::camera_image_t*)’: /root/catkin_uc/src/usb_cam/src/camera_driver.cpp:779:8: error: ‘avcodec_send_packet’ was not declared in this scope if(avcodec_send_packet(avcodec_context, avpkt) < 0) ^~~~~~~~~~~~~~~~~~~ /root/catkin_uc/src/usb_cam/src/camera_driver.cpp:779:8: note: suggested alternative: ‘av_append_packet’ if(avcodec_send_packet(avcodec_context, avpkt) < 0) ^~~~~~~~~~~~~~~~~~~ av_append_packet /root/catkin_uc/src/usb_cam/src/camera_driver.cpp:792:9: error: ‘avcodec_receive_frame’ was not declared in this scope if (avcodec_receive_frame(avcodec_context, avframe_camera) < 0) ^~~~~~~~~~~~~~~~~~~~~ /root/catkin_uc/src/usb_cam/src/camera_driver.cpp:792:9: note: suggested alternative: ‘avcodec_free_frame’ if (avcodec_receive_frame(avcodec_context, avframe_camera) < 0) ^~~~~~~~~~~~~~~~~~~~~ avcodec_free_frame usb_cam/CMakeFiles/v4l_driver.dir/build.make:110: recipe for target 'usb_cam/CMakeFiles/v4l_driver.dir/src/camera_driver.cpp.o' failed make[2]: *** [usb_cam/CMakeFiles/v4l_driver.dir/src/camera_driver.cpp.o] Error 1 CMakeFiles/Makefile2:656: recipe for target 'usb_cam/CMakeFiles/v4l_driver.dir/all' failed make[1]: *** [usb_cam/CMakeFiles/v4l_driver.dir/all] Error 2 Makefile:140: recipe for target 'all' failed make: *** [all] Error 2 Invoking "make -j4 -l4" failed

根据您提供的错误信息，看起来编译过程中发生了一些与FFmpeg相关的问题。错误信息指出了一些FFmpeg函数未声明的错误。

从错误信息中可以看到以下几个函数未声明的错误：

- `av_packet_free` => 建议使用 `av_packet_unref`
- `av_packet_alloc` => 建议使用 `av_packet_alloc`
- `avcodec_send_packet` => 建议使用 `avcodec_send_packet`
- `avcodec_receive_frame` => 建议使用 `avcodec_receive_frame`

这些错误可能是由于FFmpeg版本不兼容或配置问题导致的。

解决这些错误的方法是：

1. 确保已正确安装FFmpeg库，以及头文件和库文件的路径设置正确。
2. 检查代码中是否有使用正确的FFmpeg函数名称。
3. 确保您的代码与所使用的FFmpeg版本兼容。

如果您是在ROS工作空间中进行编译，可以尝试以下步骤：

1. 确保已正确安装FFmpeg和相关的开发包。可以尝试通过命令 `apt-get install ffmpeg` 或 `apt-get install libavcodec-dev libavformat-dev libswscale-dev` 安装所需的包。
2. 在您的ROS工作空间的`CMakeLists.txt`文件中添加以下行：

   find_package(FFmpeg REQUIRED)
   include_directories(${FFMPEG_INCLUDE_DIRS})
   target_link_libraries(your_package_name ${FFMPEG_LIBRARIES})

将 `your_package_name` 替换为您的软件包名称。

3. 重新编译并检查是否仍然存在错误。

如果问题仍然存在，请确保您的代码中使用的FFmpeg函数与所安装的FFmpeg版本兼容，或者尝试升级您的FFmpeg版本。

如果上述方法无法解决问题，请提供更多关于您的编译环境和代码的详细信息，以便更好地帮助您解决问题。

Building CXX object CMakeFiles/usb_cam.dir/src/usb_cam.cpp.o /home/q/catkin_ws/src/usb_cam/src/usb_cam.cpp: In static member function ‘static void usb_cam::UsbCam::frame_timer_callback(const ros::TimerEvent&)’: /home/q/catkin_ws/src/usb_cam/src/usb_cam.cpp:306:24: error: ‘make_unique’ is not a member of ‘std’ auto ci = std::make_unique<sensor_msgs::CameraInfo>(camera_info->getCameraInfo()); ^~~~~~~~~~~ /home/q/catkin_ws/src/usb_cam/src/usb_cam.cpp:306:24: note: suggested alternative: ‘__unique’ auto ci = std::make_unique<sensor_msgs::CameraInfo>(camera_info->getCameraInfo()); ^~~~~~~~~~~ __unique /home/q/catkin_ws/src/usb_cam/src/usb_cam.cpp:306:59: error: expected primary-expression before ‘>’ token auto ci = std::make_unique<sensor_msgs::CameraInfo>(camera_info->getCameraInfo()); ^ CMakeFiles/usb_cam.dir/build.make:62: recipe for target 'CMakeFiles/usb_cam.dir/src/usb_cam.cpp.o' failed make[2]: *** [CMakeFiles/usb_cam.dir/src/usb_cam.cpp.o] Error 1 CMakeFiles/Makefile2:67: recipe for target 'CMakeFiles/usb_cam.dir/all' failed make[1]: *** [CMakeFiles/usb_cam.dir/all] Error 2 Makefile:140: recipe for target 'all' failed make: *** [all] Error 2

这是一个编译错误，它指出在文件`/home/q/catkin_ws/src/usb_cam/src/usb_cam.cpp`的第306行中，`std`命名空间中不存在`make_unique`，它建议使用`__unique`作为替代。

这通常是因为编译器版本较旧导致的问题。`make_unique`是C++11中引入的智能指针创建函数，因此您需要确保您使用的编译器支持C++11。

您可以尝试升级您的编译器版本，或者在编译选项中添加`-std=c++11`或更高版本的标志。如果您使用的是ROS，则可以在`CMakeLists.txt`文件中添加以下行来设置编译器标志：

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")

这将确保使用C++11的编译器选项来编译您的代码。