Visual Servoing Platform  version 3.6.1 under development (2024-03-18)
tutorial-grabber-v4l2.cpp
1 
2 #include <visp3/core/vpImage.h>
3 #include <visp3/gui/vpDisplayOpenCV.h>
4 #include <visp3/gui/vpDisplayX.h>
5 #include <visp3/io/vpImageStorageWorker.h>
6 #include <visp3/sensor/vpV4l2Grabber.h>
7 
8 #define USE_COLOR // Comment to acquire gray level images
9 
10 void usage(const char *argv[], int error)
11 {
12  std::cout << "SYNOPSIS" << std::endl
13  << " " << argv[0] << " [--device <index>]"
14  << " [--scale <subsampling factor>]"
15  << " [--seqname <sequence name>]"
16  << " [--record <mode>]"
17  << " [--no-display]"
18  << " [--help] [-h]" << std::endl
19  << std::endl;
20  std::cout << "DESCRIPTION" << std::endl
21  << " --device <index> " << std::endl
22  << " Camera device index. Set 0 to dial with the first camera," << std::endl
23  << " and 1 to dial with the second camera attached to the computer." << std::endl
24  << " Default: 0 to consider /dev/video0 device." << std::endl
25  << std::endl
26  << " --scale <subsampling factor>" << std::endl
27  << " Subsampling factor applied to the images captured by the device." << std::endl
28  << " Default: 1" << std::endl
29  << std::endl
30  << " --seqname <sequence name>" << std::endl
31  << " Name of the sequence of image to create (ie: /tmp/image%04d.jpg)." << std::endl
32  << " Default: empty." << std::endl
33  << std::endl
34  << " --record <mode>" << std::endl
35  << " Allowed values for mode are:" << std::endl
36  << " 0: record all the captures images (continuous mode)," << std::endl
37  << " 1: record only images selected by a user click (single shot mode)." << std::endl
38  << " Default mode: 0" << std::endl
39  << std::endl
40  << " --no-display" << std::endl
41  << " Disable displaying captured images." << std::endl
42  << " When used and sequence name specified, record mode is internally set to 1 (continuous mode)."
43  << std::endl
44  << std::endl
45  << " --help, -h" << std::endl
46  << " Print this helper message." << std::endl
47  << std::endl;
48  std::cout << "USAGE" << std::endl
49  << " Example to visualize images:" << std::endl
50  << " " << argv[0] << std::endl
51  << std::endl
52  << " Example to visualize images from a second camera:" << std::endl
53  << " " << argv[0] << " --device 1" << std::endl
54  << std::endl
55  << " Examples to record a sequence:" << std::endl
56  << " " << argv[0] << " --seqname I%04d.png" << std::endl
57  << " " << argv[0] << " --seqname folder/I%04d.png --record 0" << std::endl
58  << std::endl
59  << " Examples to record single shot images:\n"
60  << " " << argv[0] << " --seqname I%04d.png --record 1\n"
61  << " " << argv[0] << " --seqname folder/I%04d.png --record 1" << std::endl
62  << std::endl;
63 
64  if (error) {
65  std::cout << "Error" << std::endl
66  << " "
67  << "Unsupported parameter " << argv[error] << std::endl;
68  }
69 }
70 
77 int main(int argc, const char *argv[])
78 {
79 #if defined(VISP_HAVE_V4L2) && defined(VISP_HAVE_THREADS)
80  try {
81  int opt_device = 0;
82  unsigned int opt_scale = 1; // Default value is 2 in the constructor. Turn
83  // it to 1 to avoid subsampling
84  std::string opt_seqname;
85  int opt_record_mode = 0;
86  bool opt_display = true;
87 
88  for (int i = 1; i < argc; i++) {
89  if (std::string(argv[i]) == "--device") {
90  opt_device = std::atoi(argv[i + 1]);
91  i++;
92  }
93  else if (std::string(argv[i]) == "--scale") {
94  opt_scale = (unsigned int)atoi(argv[i + 1]);
95  i++;
96  }
97  else if (std::string(argv[i]) == "--seqname") {
98  opt_seqname = std::string(argv[i + 1]);
99  i++;
100  }
101  else if (std::string(argv[i]) == "--record") {
102  opt_record_mode = std::atoi(argv[i + 1]);
103  i++;
104  }
105  else if (std::string(argv[i]) == "--no-display") {
106  opt_display = false;
107  }
108  else if (std::string(argv[i]) == "--help" || std::string(argv[i]) == "-h") {
109  usage(argv, 0);
110  return EXIT_SUCCESS;
111  }
112  else {
113  usage(argv, i);
114  return EXIT_FAILURE;
115  }
116  }
117 
118  if ((!opt_display) && (!opt_seqname.empty())) {
119  opt_record_mode = 0;
120  }
121  std::cout << "Use device : " << opt_device << std::endl;
122  std::cout << "Recording : " << (opt_seqname.empty() ? "disabled" : "enabled") << std::endl;
123  std::cout << "Display : " << (opt_display ? "enabled" : "disabled") << std::endl;
124 
125  std::string text_record_mode =
126  std::string("Record mode: ") + (opt_record_mode ? std::string("single") : std::string("continuous"));
127 
128  if (!opt_seqname.empty()) {
129  std::cout << text_record_mode << std::endl;
130  std::cout << "Record name: " << opt_seqname << std::endl;
131  }
132 
133 #ifdef USE_COLOR
134  vpImage<vpRGBa> I; // To acquire color images
135 #else
136  vpImage<unsigned char> I; // To acquire gray images
137 #endif
138 
139  vpV4l2Grabber g;
140  std::ostringstream device;
141  device << "/dev/video" << opt_device;
142  g.setDevice(device.str());
143  g.setScale(opt_scale);
144  g.open(I);
145 
146  std::cout << "Image size : " << I.getWidth() << " " << I.getHeight() << std::endl;
147 
148  vpDisplay *d = nullptr;
149  if (opt_display) {
150 #if !(defined(VISP_HAVE_X11) || defined(VISP_HAVE_OPENCV))
151  std::cout << "No image viewer is available..." << std::endl;
152  opt_display = false;
153 #endif
154  }
155  if (opt_display) {
156 #ifdef VISP_HAVE_X11
157  d = new vpDisplayX(I);
158 #elif defined(HAVE_OPENCV_HIGHGUI)
159  d = new vpDisplayOpenCV(I);
160 #endif
161  }
162 
163 #ifdef USE_COLOR
164  vpImageQueue<vpRGBa> image_queue(opt_seqname, opt_record_mode);
165  vpImageStorageWorker<vpRGBa> image_storage_worker(std::ref(image_queue));
166  std::thread image_storage_thread(&vpImageStorageWorker<vpRGBa>::run, &image_storage_worker);
167 #else
168  vpImageQueue<unsigned char> image_queue(opt_seqname, opt_record_mode);
169  vpImageStorageWorker<unsigned char> image_storage_worker(std::ref(image_queue));
170  std::thread image_storage_thread(&vpImageStorageWorker<unsigned char>::run, &image_storage_worker);
171 #endif
172 
173  bool quit = false;
174  while (!quit) {
175  double t = vpTime::measureTimeMs();
176  g.acquire(I);
177 
179 
180  quit = image_queue.record(I);
181 
182  std::stringstream ss;
183  ss << "Acquisition time: " << std::setprecision(3) << vpTime::measureTimeMs() - t << " ms";
184  vpDisplay::displayText(I, I.getHeight() - 20, 10, ss.str(), vpColor::red);
185  vpDisplay::flush(I);
186  }
187  image_queue.cancel();
188  image_storage_thread.join();
189 
190  if (d) {
191  delete d;
192  }
193  }
194  catch (const vpException &e) {
195  std::cout << "Catch an exception: " << e << std::endl;
196  }
197 #else
198  (void)argc;
199  (void)argv;
200 #ifndef VISP_HAVE_V4L2
201  std::cout << "Install Video 4 Linux 2 (v4l2), configure and build ViSP again to use this example" << std::endl;
202 #endif
203 #if (VISP_CXX_STANDARD < VISP_CXX_STANDARD_11)
204  std::cout << "This tutorial should be built with c++11 support" << std::endl;
205 #endif
206 
207 #endif
208 }
static const vpColor red
Definition: vpColor.h:211
The vpDisplayOpenCV allows to display image using the OpenCV library. Thus to enable this class OpenC...
Use the X11 console to display images on unix-like OS. Thus to enable this class X11 should be instal...
Definition: vpDisplayX.h:128
Class that defines generic functionalities for display.
Definition: vpDisplay.h:173
static void display(const vpImage< unsigned char > &I)
static void flush(const vpImage< unsigned char > &I)
static void displayText(const vpImage< unsigned char > &I, const vpImagePoint &ip, const std::string &s, const vpColor &color)
error that can be emitted by ViSP classes.
Definition: vpException.h:59
unsigned int getWidth() const
Definition: vpImage.h:249
unsigned int getHeight() const
Definition: vpImage.h:184
Class that is a wrapper over the Video4Linux2 (V4L2) driver.
void open(vpImage< unsigned char > &I)
void setScale(unsigned scale=vpV4l2Grabber::DEFAULT_SCALE)
void setDevice(const std::string &devname)
void acquire(vpImage< unsigned char > &I)
VISP_EXPORT double measureTimeMs()