crossdesk/src/screen_capturer/linux/screen_capturer_x11.cpp

#include "screen_capturer_x11.h"

#include <chrono>
#include <thread>

#include "libyuv.h"
#include "rd_log.h"

namespace crossdesk {

ScreenCapturerX11::ScreenCapturerX11() {}

ScreenCapturerX11::~ScreenCapturerX11() { Destroy(); }

int ScreenCapturerX11::Init(const int fps, cb_desktop_data cb) {
  display_ = XOpenDisplay(nullptr);
  if (!display_) {
    LOG_ERROR("Cannot connect to X server");
    return -1;
  }

  root_ = DefaultRootWindow(display_);
  screen_res_ = XRRGetScreenResources(display_, root_);
  if (!screen_res_) {
    LOG_ERROR("Failed to get screen resources");
    XCloseDisplay(display_);
    return 1;
  }

  for (int i = 0; i < screen_res_->noutput; ++i) {
    RROutput output = screen_res_->outputs[i];
    XRROutputInfo* output_info =
        XRRGetOutputInfo(display_, screen_res_, output);

    if (output_info->connection == RR_Connected && output_info->crtc != 0) {
      XRRCrtcInfo* crtc_info =
          XRRGetCrtcInfo(display_, screen_res_, output_info->crtc);

      display_info_list_.push_back(
          DisplayInfo((void*)display_, output_info->name, true, crtc_info->x,
                      crtc_info->y, crtc_info->width, crtc_info->height));

      XRRFreeCrtcInfo(crtc_info);
    }

    if (output_info) {
      XRRFreeOutputInfo(output_info);
    }
  }

  XWindowAttributes attr;
  XGetWindowAttributes(display_, root_, &attr);

  width_ = attr.width;
  height_ = attr.height;

  if (width_ % 2 != 0 || height_ % 2 != 0) {
    LOG_ERROR("Width and height must be even numbers");
    return -2;
  }

  fps_ = fps;
  callback_ = cb;

  y_plane_.resize(width_ * height_);
  uv_plane_.resize((width_ / 2) * (height_ / 2) * 2);

  return 0;
}

int ScreenCapturerX11::Destroy() {
  Stop();

  y_plane_.clear();
  uv_plane_.clear();

  if (screen_res_) {
    XRRFreeScreenResources(screen_res_);
    screen_res_ = nullptr;
  }

  if (display_) {
    XCloseDisplay(display_);
    display_ = nullptr;
  }
  return 0;
}

int ScreenCapturerX11::Start() {
  if (running_) return 0;
  running_ = true;
  paused_ = false;
  thread_ = std::thread([this]() {
    while (running_) {
      if (!paused_) OnFrame();
    }
  });
  return 0;
}

int ScreenCapturerX11::Stop() {
  if (!running_) return 0;
  running_ = false;
  if (thread_.joinable()) thread_.join();
  return 0;
}

int ScreenCapturerX11::Pause(int monitor_index) {
  paused_ = true;
  return 0;
}

int ScreenCapturerX11::Resume(int monitor_index) {
  paused_ = false;
  return 0;
}

int ScreenCapturerX11::SwitchTo(int monitor_index) {
  monitor_index_ = monitor_index;
  return 0;
}

std::vector<DisplayInfo> ScreenCapturerX11::GetDisplayInfoList() {
  return display_info_list_;
}

void ScreenCapturerX11::OnFrame() {
  if (!display_) {
    LOG_ERROR("Display is not initialized");
    return;
  }

  if (monitor_index_ < 0 || monitor_index_ >= display_info_list_.size()) {
    LOG_ERROR("Invalid monitor index: {}", monitor_index_.load());
    return;
  }

  left_ = display_info_list_[monitor_index_].left;
  top_ = display_info_list_[monitor_index_].top;
  width_ = display_info_list_[monitor_index_].width;
  height_ = display_info_list_[monitor_index_].height;

  XImage* image = XGetImage(display_, root_, left_, top_, width_, height_,
                            AllPlanes, ZPixmap);
  if (!image) return;

  bool needs_copy = image->bytes_per_line != width_ * 4;
  std::vector<uint8_t> argb_buf;
  uint8_t* src_argb = nullptr;

  if (needs_copy) {
    argb_buf.resize(width_ * height_ * 4);
    for (int y = 0; y < height_; ++y) {
      memcpy(&argb_buf[y * width_ * 4], image->data + y * image->bytes_per_line,
             width_ * 4);
    }
    src_argb = argb_buf.data();
  } else {
    src_argb = reinterpret_cast<uint8_t*>(image->data);
  }

  libyuv::ARGBToNV12(src_argb, width_ * 4, y_plane_.data(), width_,
                     uv_plane_.data(), width_, width_, height_);

  std::vector<uint8_t> nv12;
  nv12.reserve(y_plane_.size() + uv_plane_.size());
  nv12.insert(nv12.end(), y_plane_.begin(), y_plane_.end());
  nv12.insert(nv12.end(), uv_plane_.begin(), uv_plane_.end());

  if (callback_) {
    callback_(nv12.data(), width_ * height_ * 3 / 2, width_, height_,
              display_info_list_[monitor_index_].name.c_str());
  }

  XDestroyImage(image);
}
}  // namespace crossdesk