apollo::dreamview::ImageHandler类 参考

The ImageHandler, built on top of CivetHandler, converts the received ROS image message to an image stream, wrapped by MJPEG Streaming Protocol. 更多...

#include <image_handler.h>

类 apollo::dreamview::ImageHandler 继承关系图:

apollo::dreamview::ImageHandler 的协作图:

Public 成员函数
	ImageHandler ()
bool	handleGet (CivetServer *server, struct mg_connection *conn)
template<>
void	OnImage (const std::shared_ptr< Image > &image)
template<>
void	OnImage (const std::shared_ptr< CompressedImage > &compressed_image)

静态 Public 属性
static constexpr double	kImageScale = 0.2

详细描述

The ImageHandler, built on top of CivetHandler, converts the received ROS image message to an image stream, wrapped by MJPEG Streaming Protocol.

在文件 image_handler.h 第 44 行定义.

构造及析构函数说明

ImageHandler()

apollo::dreamview::ImageHandler::ImageHandler

(

)

在文件 image_handler.cc 第 85 行定义.

    : requests_(0), node_(cyber::CreateNode("image_handler")) {
  node_->CreateReader<Image>(
      FLAGS_image_front_topic,
      [this](const std::shared_ptr<Image> &image) { OnImageFront(image); });
 
  node_->CreateReader<CompressedImage>(
      FLAGS_image_short_topic,
      [this](const std::shared_ptr<CompressedImage> &image) {
        OnImageShort(image);
      });
}

成员函数说明

handleGet()

bool apollo::dreamview::ImageHandler::handleGet	(	CivetServer *	server,
		struct mg_connection *	conn
	)

在文件 image_handler.cc 第 98 行定义.

                                                                            {
  requests_++;
 
  mg_printf(conn,
            "HTTP/1.1 200 OK\r\n"
            "Connection: close\r\n"
            "Max-Age: 0\r\n"
            "Expires: 0\r\n"
            "Cache-Control: no-cache, no-store, must-revalidate, private\r\n"
            "Pragma: no-cache\r\n"
            "Content-Type: multipart/x-mixed-replace; "
            "boundary=--BoundaryString\r\n"
            "\r\n");
 
  std::vector<uchar> to_send;
  while (true) {
    {
      std::unique_lock<std::mutex> lock(mutex_);
      to_send = send_buffer_;
    }
 
    if (!to_send.empty()) {
      // Sends the image data
      mg_printf(conn,
                "--BoundaryString\r\n"
                "Content-type: image/jpeg\r\n"
                "Content-Length: %zu\r\n"
                "\r\n",
                to_send.size());
 
      if (mg_write(conn, &to_send[0], to_send.size()) <= 0) {
        requests_--;
        return false;
      }
      mg_printf(conn, "\r\n\r\n");
    }
 
    std::unique_lock<std::mutex> lock(mutex_);
    cvar_.wait(lock);
  }
 
  requests_--;
  return true;
}

OnImage() [1/2]

template<>

void apollo::dreamview::ImageHandler::OnImage

(

const std::shared_ptr< CompressedImage > &

compressed_image

)

在文件 image_handler.cc 第 54 行定义.

                                                            {
  if (requests_ == 0 ||
      compressed_image->format() == "h265" /* skip video format */) {
    return;
  }
 
  std::vector<uint8_t> compressed_raw_data(compressed_image->data().begin(),
                                           compressed_image->data().end());
  cv::Mat mat_image = cv::imdecode(compressed_raw_data, cv::IMREAD_COLOR);
 
  std::unique_lock<std::mutex> lock(mutex_);
  cv::imencode(".jpg", mat_image, send_buffer_,
               std::vector<int>() /* params */);
  cvar_.notify_all();
}

OnImage() [2/2]

template<>

void apollo::dreamview::ImageHandler::OnImage

(

const std::shared_ptr< Image > &

image

)

在文件 image_handler.cc 第 34 行定义.

                                                            {
  if (requests_ == 0) {
    return;
  }
 
  cv::Mat mat(image->height(), image->width(), CV_8UC3,
              const_cast<char *>(image->data().data()), image->step());
  cv::cvtColor(mat, mat, cv::COLOR_RGB2BGR);
  cv::resize(
      mat, mat,
      cv::Size(static_cast<int>(image->width() * ImageHandler::kImageScale),
               static_cast<int>(image->height() * ImageHandler::kImageScale)),
      0, 0, cv::INTER_LINEAR);
 
  std::unique_lock<std::mutex> lock(mutex_);
  cv::imencode(".jpg", mat, send_buffer_, std::vector<int>() /* params */);
  cvar_.notify_all();
}

类成员变量说明

kImageScale

constexpr double apollo::dreamview::ImageHandler::kImageScale = 0.2

staticconstexpr

在文件 image_handler.h 第 47 行定义.

---

该类的文档由以下文件生成:

• modules/dreamview/backend/common/handlers/image_handler.h
• modules/dreamview/backend/common/handlers/image_handler.cc