tutorial-grabber-v4l2.cpp

#include <visp3/core/vpConfig.h>
#include <visp3/core/vpImage.h>
#include <visp3/gui/vpDisplayFactory.h>
#include <visp3/io/vpImageStorageWorker.h>
#include <visp3/sensor/vpV4l2Grabber.h>
 
#define USE_COLOR // Comment to acquire gray level images
 
void usage(const char *argv[], int error)
{
  std::cout << "SYNOPSIS" << std::endl
    << "  " << argv[0] << " [--device <index>]"
    << " [--scale <subsampling factor>]"
    << " [--seqname <sequence name>]"
    << " [--record <mode>]"
    << " [--no-display]"
    << " [--help] [-h]" << std::endl
    << std::endl;
  std::cout << "DESCRIPTION" << std::endl
    << "  --device <index> " << std::endl
    << "    Camera device index. Set 0 to dial with the first camera," << std::endl
    << "    and 1 to dial with the second camera attached to the computer." << std::endl
    << "    Default: 0 to consider /dev/video0 device." << std::endl
    << std::endl
    << "  --scale <subsampling factor>" << std::endl
    << "    Subsampling factor applied to the images captured by the device." << std::endl
    << "    Default: 1" << std::endl
    << std::endl
    << "  --seqname <sequence name>" << std::endl
    << "    Name of the sequence of image to create (ie: /tmp/image%04d.jpg)." << std::endl
    << "    Default: empty." << std::endl
    << std::endl
    << "  --record <mode>" << std::endl
    << "    Allowed values for mode are:" << std::endl
    << "      0: record all the captures images (continuous mode)," << std::endl
    << "      1: record only images selected by a user click (single shot mode)." << std::endl
    << "    Default mode: 0" << std::endl
    << std::endl
    << "  --no-display" << std::endl
    << "    Disable displaying captured images." << std::endl
    << "    When used and sequence name specified, record mode is internally set to 1 (continuous mode)."
    << std::endl
    << std::endl
    << "  --help, -h" << std::endl
    << "    Print this helper message." << std::endl
    << std::endl;
  std::cout << "USAGE" << std::endl
    << "  Example to visualize images:" << std::endl
    << "    " << argv[0] << std::endl
    << std::endl
    << "  Example to visualize images from a second camera:" << std::endl
    << "    " << argv[0] << " --device 1" << std::endl
    << std::endl
    << "  Examples to record a sequence:" << std::endl
    << "    " << argv[0] << " --seqname I%04d.png" << std::endl
    << "    " << argv[0] << " --seqname folder/I%04d.png --record 0" << std::endl
    << std::endl
    << "  Examples to record single shot images:\n"
    << "    " << argv[0] << " --seqname I%04d.png --record 1\n"
    << "    " << argv[0] << " --seqname folder/I%04d.png --record 1" << std::endl
    << std::endl;
 
  if (error) {
    std::cout << "Error" << std::endl
      << "  "
      << "Unsupported parameter " << argv[error] << std::endl;
  }
}

int main(int argc, const char *argv[])
{
#if defined(VISP_HAVE_V4L2) && defined(VISP_HAVE_THREADS)
#ifdef ENABLE_VISP_NAMESPACE
  using namespace VISP_NAMESPACE_NAME;
#endif
#if (VISP_CXX_STANDARD >= VISP_CXX_STANDARD_11)
  std::shared_ptr<vpDisplay> display;
#else
  vpDisplay *display = nullptr;
#endif
  try {
    int opt_device = 0;
    unsigned int opt_scale = 1; // Default value is 2 in the constructor. Turn
                                // it to 1 to avoid subsampling
    std::string opt_seqname;
    int opt_record_mode = 0;
    bool opt_display = true;
 
    for (int i = 1; i < argc; i++) {
      if (std::string(argv[i]) == "--device" && i + 1 < argc) {
        opt_device = std::atoi(argv[++i]);
      }
      else if (std::string(argv[i]) == "--scale" && i + 1 < argc) {
        opt_scale = static_cast<unsigned int>(atoi(argv[++i]));
      }
      else if (std::string(argv[i]) == "--seqname" && i + 1 < argc) {
        opt_seqname = std::string(argv[++i]);
      }
      else if (std::string(argv[i]) == "--record" && i + 1 < argc) {
        opt_record_mode = std::atoi(argv[++i]);
      }
      else if (std::string(argv[i]) == "--no-display") {
        opt_display = false;
      }
      else if (std::string(argv[i]) == "--help" || std::string(argv[i]) == "-h") {
        usage(argv, 0);
        return EXIT_SUCCESS;
      }
      else {
        usage(argv, i);
        return EXIT_FAILURE;
      }
    }
 
    if ((!opt_display) && (!opt_seqname.empty())) {
      opt_record_mode = 0;
    }
    std::cout << "Use device : " << opt_device << std::endl;
    std::cout << "Recording  : " << (opt_seqname.empty() ? "disabled" : "enabled") << std::endl;
    std::cout << "Display    : " << (opt_display ? "enabled" : "disabled") << std::endl;
 
    std::string text_record_mode =
      std::string("Record mode: ") + (opt_record_mode ? std::string("single") : std::string("continuous"));
 
    if (!opt_seqname.empty()) {
      std::cout << text_record_mode << std::endl;
      std::cout << "Record name: " << opt_seqname << std::endl;
    }
 
#ifdef USE_COLOR
    vpImage<vpRGBa> I; // To acquire color images
#else
    vpImage<unsigned char> I; // To acquire gray images
#endif
 
    vpV4l2Grabber g;
    std::ostringstream device;
    device << "/dev/video" << opt_device;
    g.setDevice(device.str());
    g.setScale(opt_scale);
    g.open(I);
 
    std::cout << "Image size : " << I.getWidth() << " " << I.getHeight() << std::endl;
 
    if (opt_display) {
#if !(defined(VISP_HAVE_DISPLAY))
      std::cout << "No image viewer is available..." << std::endl;
      opt_display = false;
#else
#if (VISP_CXX_STANDARD >= VISP_CXX_STANDARD_11)
      display = vpDisplayFactory::createDisplay(I);
#else
      display = vpDisplayFactory::allocateDisplay(I);
#endif
#endif
    }
 
#ifdef USE_COLOR
    vpImageQueue<vpRGBa> image_queue(opt_seqname, opt_record_mode);
    vpImageStorageWorker<vpRGBa> image_storage_worker(std::ref(image_queue));
    std::thread image_storage_thread(&vpImageStorageWorker<vpRGBa>::run, &image_storage_worker);
#else
    vpImageQueue<unsigned char> image_queue(opt_seqname, opt_record_mode);
    vpImageStorageWorker<unsigned char> image_storage_worker(std::ref(image_queue));
    std::thread image_storage_thread(&vpImageStorageWorker<unsigned char>::run, &image_storage_worker);
#endif
 
    bool quit = false;
    while (!quit) {
      double t = vpTime::measureTimeMs();
      g.acquire(I);
 
      vpDisplay::display(I);
 
      quit = image_queue.record(I);
 
      std::stringstream ss;
      ss << "Acquisition time: " << std::setprecision(3) << vpTime::measureTimeMs() - t << " ms";
      vpDisplay::displayText(I, I.getHeight() - 20, 10, ss.str(), vpColor::red);
      vpDisplay::flush(I);
    }
    image_queue.cancel();
    image_storage_thread.join();
  }
  catch (const vpException &e) {
    std::cout << "Catch an exception: " << e << std::endl;
  }
 
#if (VISP_CXX_STANDARD < VISP_CXX_STANDARD_11)
  if (display != nullptr) {
    delete display;
  }
#endif
#else
  (void)argc;
  (void)argv;
#ifndef VISP_HAVE_V4L2
  std::cout << "Install Video 4 Linux 2 (v4l2), configure and build ViSP again to use this example" << std::endl;
#endif
#if (VISP_CXX_STANDARD < VISP_CXX_STANDARD_11)
  std::cout << "This tutorial should be built with c++11 support" << std::endl;
#endif
 
#endif
}