Visual Servoing Platform  version 3.5.0 under development (2022-02-15)
tutorial-grabber-v4l2.cpp
#include <visp3/core/vpImage.h>
#include <visp3/gui/vpDisplayX.h>
#include <visp3/gui/vpDisplayOpenCV.h>
#include <visp3/sensor/vpV4l2Grabber.h>
#include <visp3/io/vpImageStorageWorker.h>
//#define USE_COLOR // Comment to acquire gray level images
int main(int argc, const char *argv[])
{
#if defined(VISP_HAVE_V4L2) && (VISP_CXX_STANDARD >= VISP_CXX_STANDARD_11)
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;
for (int i = 0; i < argc; i++) {
if (std::string(argv[i]) == "--camera_device")
opt_device = std::atoi(argv[i + 1]);
else if (std::string(argv[i]) == "--scale")
opt_scale = (unsigned int)atoi(argv[i + 1]);
else if (std::string(argv[i]) == "--seqname")
opt_seqname = std::string(argv[i + 1]);
else if (std::string(argv[i]) == "--record")
opt_record_mode = std::atoi(argv[i + 1]);
else if (std::string(argv[i]) == "--help" || std::string(argv[i]) == "-h") {
std::cout << "\nUsage: " << argv[0]
<< " [--camera_device <camera device (default: 0)>] [--scale <subsampling factor (default: 1)>]"
" [--seqname <sequence name (default: empty>] [--record <0: continuous | 1: single shot (default: 0)>]"
" [--help] [-h]\n"
<< "\nExample to visualize images:\n"
<< " " << argv[0] << "\n"
<< "\nExample to visualize images from a second camera:\n"
<< " " << argv[0] << " --camera_device 1\n"
<< "\nExamples to record a sequence:\n"
<< " " << argv[0] << " --seqname I%04d.png \n"
<< " " << argv[0] << " --seqname folder/I%04d.png --record 0\n"
<< "\nExamples to record single shot images:\n"
<< " " << argv[0] << " --seqname I%04d.png --record 1\n"
<< " " << argv[0] << " --seqname folder/I%04d.png --record 1\n"
<< std::endl;
return 0;
}
}
std::cout << "Use device : " << opt_device << std::endl;
std::cout << "Recording : " << (opt_seqname.empty() ? "disabled" : "enabled") << 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
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;
#ifdef VISP_HAVE_X11
vpDisplayX d(I);
#elif defined(VISP_HAVE_OPENCV)
#else
std::cout << "No image viewer is available..." << std::endl;
#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);
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);
}
image_queue.cancel();
image_storage_thread.join();
} catch (const vpException &e) {
std::cout << "Catch an exception: " << e << std::endl;
}
#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 turorial should be built with c++11 support" << std::endl;
#endif
#endif
}