Visual Servoing Platform  version 3.2.0 under development (2018-10-20)
grabV4l2MultiCpp11Thread.cpp

Example of using V4l2 backend to capture multiple camera streams with C++11 threads.

/****************************************************************************
*
* This file is part of the ViSP software.
* Copyright (C) 2005 - 2017 by Inria. All rights reserved.
*
* This software is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
* See the file LICENSE.txt at the root directory of this source
* distribution for additional information about the GNU GPL.
*
* For using ViSP with software that can not be combined with the GNU
* GPL, please contact Inria about acquiring a ViSP Professional
* Edition License.
*
* See http://visp.inria.fr for more information.
*
* This software was developed at:
* Inria Rennes - Bretagne Atlantique
* Campus Universitaire de Beaulieu
* 35042 Rennes Cedex
* France
*
* If you have questions regarding the use of this file, please contact
* Inria at visp@inria.fr
*
* This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
* WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
* Description:
* Acquire images using 1394 device with cfox (MAC OSX) and display it
* using GTK or GTK.
*
* Authors:
* Fabien Spindler
*
*****************************************************************************/
#include <iostream>
#include <visp3/core/vpConfig.h>
#if defined(VISP_HAVE_CPP11_COMPATIBILITY) && defined(VISP_HAVE_V4L2) && \
(defined(VISP_HAVE_X11) || defined(VISP_HAVE_GTK))
#include <condition_variable>
#include <iostream>
#include <limits>
#include <mutex>
#include <queue>
#include <thread>
#include <visp3/core/vpDisplay.h>
#include <visp3/core/vpImageFilter.h>
#include <visp3/core/vpIoTools.h>
#include <visp3/core/vpTime.h>
#include <visp3/gui/vpDisplayGTK.h>
#include <visp3/gui/vpDisplayX.h>
#include <visp3/io/vpParseArgv.h>
#include <visp3/io/vpVideoWriter.h>
#include <visp3/sensor/vpV4l2Grabber.h>
#define GETOPTARGS "d:oh"
namespace
{
void usage(const char *name, const char *badparam)
{
fprintf(stdout, "\n\
SYNOPSIS:\n\
%s [-d <device count>] [-o] [-h]\n\
\n\
DESCRIPTION:\n\
Capture multiple camera streams and save the stream without slowing down the acquisition.\n\
\n\
OPTIONS: \n\
-d <device count> \n\
Open the specified number of camera streams.\n\
\n\
-o \n\
Save each stream in a dedicated folder.\n\
\n\
-h \n\
Print the help.\n\n", name);
if (badparam)
fprintf(stdout, "\nERROR: Bad parameter [%s]\n", badparam);
}
bool getOptions(int argc, char **argv, unsigned int &deviceCount, bool &saveVideo)
{
const char *optarg;
const char **argv1 = (const char **)argv;
int c;
while ((c = vpParseArgv::parse(argc, argv1, GETOPTARGS, &optarg)) > 1) {
switch (c) {
case 'd':
deviceCount = (unsigned int)atoi(optarg);
break;
case 'o':
saveVideo = true;
break;
case 'h':
usage(argv[0], NULL);
return false;
break;
default:
usage(argv[0], optarg);
return false;
break;
}
}
if ((c == 1) || (c == -1)) {
// standalone param or error
usage(argv[0], NULL);
std::cerr << "ERROR: " << std::endl;
std::cerr << " Bad argument " << optarg << std::endl << std::endl;
return false;
}
return true;
}
// Code adapted from the original author Dan MaĊĦek to be compatible with ViSP
// image
class FrameQueue
{
public:
struct cancelled {
};
FrameQueue()
: m_cancelled(false), m_cond(), m_queueColor(), m_maxQueueSize(std::numeric_limits<size_t>::max()), m_mutex()
{
}
void cancel()
{
std::lock_guard<std::mutex> lock(m_mutex);
m_cancelled = true;
m_cond.notify_all();
}
// Push the image to save in the queue (FIFO)
void push(const vpImage<vpRGBa> &image)
{
std::lock_guard<std::mutex> lock(m_mutex);
m_queueColor.push(image);
// Pop extra images in the queue
while (m_queueColor.size() > m_maxQueueSize) {
m_queueColor.pop();
}
m_cond.notify_one();
}
// Pop the image to save from the queue (FIFO)
{
std::unique_lock<std::mutex> lock(m_mutex);
while (m_queueColor.empty()) {
if (m_cancelled) {
throw cancelled();
}
m_cond.wait(lock);
if (m_cancelled) {
throw cancelled();
}
}
vpImage<vpRGBa> image(m_queueColor.front());
m_queueColor.pop();
return image;
}
void setMaxQueueSize(const size_t max_queue_size) { m_maxQueueSize = max_queue_size; }
private:
bool m_cancelled;
std::condition_variable m_cond;
std::queue<vpImage<vpRGBa> > m_queueColor;
size_t m_maxQueueSize;
std::mutex m_mutex;
};
class StorageWorker
{
public:
StorageWorker(FrameQueue &queue, const std::string &filename, const unsigned int width, const unsigned int height)
: m_queue(queue), m_filename(filename), m_width(width), m_height(height)
{
}
// Thread main loop
void run()
{
vpImage<vpRGBa> O_color(m_height, m_width);
vpVideoWriter writer;
if (!m_filename.empty()) {
writer.setFileName(m_filename);
writer.open(O_color);
}
try {
for (;;) {
vpImage<vpRGBa> image(m_queue.pop());
if (!m_filename.empty()) {
writer.saveFrame(image);
}
}
} catch (FrameQueue::cancelled &) {
}
}
private:
FrameQueue &m_queue;
std::string m_filename;
unsigned int m_width;
unsigned int m_height;
};
class ShareImage
{
private:
bool m_cancelled;
std::condition_variable m_cond;
std::mutex m_mutex;
unsigned char *m_pImgData;
unsigned int m_totalSize;
public:
struct cancelled {
};
ShareImage() : m_cancelled(false), m_cond(), m_mutex(), m_pImgData(NULL), m_totalSize(0) {}
virtual ~ShareImage()
{
if (m_pImgData != NULL) {
delete[] m_pImgData;
}
}
void cancel()
{
std::lock_guard<std::mutex> lock(m_mutex);
m_cancelled = true;
m_cond.notify_all();
}
// Get the image to display
void getImage(unsigned char *const imageData, const unsigned int totalSize)
{
std::unique_lock<std::mutex> lock(m_mutex);
if (m_cancelled) {
throw cancelled();
}
m_cond.wait(lock);
if (m_cancelled) {
throw cancelled();
}
// Copy to imageData
if (totalSize <= m_totalSize) {
memcpy(imageData, m_pImgData, totalSize * sizeof(unsigned char));
} else {
std::cerr << "totalSize <= m_totalSize !" << std::endl;
}
}
bool isCancelled()
{
std::lock_guard<std::mutex> lock(m_mutex);
return m_cancelled;
}
// Set the image to display
void setImage(const unsigned char *const imageData, const unsigned int totalSize)
{
std::lock_guard<std::mutex> lock(m_mutex);
if (m_pImgData == NULL || m_totalSize != totalSize) {
m_totalSize = totalSize;
if (m_pImgData != NULL) {
delete[] m_pImgData;
}
m_pImgData = new unsigned char[m_totalSize];
}
// Copy from imageData
memcpy(m_pImgData, imageData, m_totalSize * sizeof(unsigned char));
m_cond.notify_one();
}
};
void capture(vpV4l2Grabber *const pGrabber, ShareImage &share_image)
{
vpImage<vpRGBa> local_img;
// Open the camera stream
pGrabber->open(local_img);
while (true) {
if (share_image.isCancelled()) {
break;
}
pGrabber->acquire(local_img);
// Update share_image
share_image.setImage((unsigned char *)local_img.bitmap, local_img.getSize() * 4);
}
}
void display(const unsigned int width, const unsigned int height, const int win_x, const int win_y,
const unsigned int deviceId, ShareImage &share_image, FrameQueue &queue, const bool save)
{
vpImage<vpRGBa> local_img(height, width);
#if defined VISP_HAVE_X11
vpDisplayX display;
#elif defined VISP_HAVE_GTK
vpDisplayGTK display;
#endif
// Init Display
std::stringstream ss;
ss << "Camera stream " << deviceId;
display.init(local_img, win_x, win_y, ss.str());
try {
vpImage<unsigned char> I_red(height, width), I_green(height, width), I_blue(height, width), I_alpha(height, width);
;
vpImage<unsigned char> I_red_gaussian(height, width), I_green_gaussian(height, width),
I_blue_gaussian(height, width);
vpImage<double> I_red_gaussian_double, I_green_gaussian_double, I_blue_gaussian_double;
bool exit = false, gaussian_blur = false;
while (!exit) {
double t = vpTime::measureTimeMs();
// Get image
share_image.getImage((unsigned char *)local_img.bitmap, local_img.getSize() * 4);
// Apply gaussian blur to simulate a computation on the image
if (gaussian_blur) {
// Split channels
vpImageConvert::split(local_img, &I_red, &I_green, &I_blue, &I_alpha);
vpImageConvert::convert(I_red, I_red_gaussian_double);
vpImageConvert::convert(I_green, I_green_gaussian_double);
vpImageConvert::convert(I_blue, I_blue_gaussian_double);
vpImageFilter::gaussianBlur(I_red_gaussian_double, I_red_gaussian_double, 21);
vpImageFilter::gaussianBlur(I_green_gaussian_double, I_green_gaussian_double, 21);
vpImageFilter::gaussianBlur(I_blue_gaussian_double, I_blue_gaussian_double, 21);
vpImageConvert::convert(I_red_gaussian_double, I_red_gaussian);
vpImageConvert::convert(I_green_gaussian_double, I_green_gaussian);
vpImageConvert::convert(I_blue_gaussian_double, I_blue_gaussian);
vpImageConvert::merge(&I_red_gaussian, &I_green_gaussian, &I_blue_gaussian, NULL, local_img);
}
std::stringstream ss;
ss << "Time: " << t << " ms";
vpDisplay::display(local_img);
vpDisplay::displayText(local_img, 20, 20, ss.str(), vpColor::red);
vpDisplay::displayText(local_img, 40, 20, "Left click to quit, right click for Gaussian blur.", vpColor::red);
vpDisplay::flush(local_img);
if (save) {
queue.push(local_img);
}
if (vpDisplay::getClick(local_img, button, false)) {
switch (button) {
gaussian_blur = !gaussian_blur;
break;
default:
exit = true;
break;
}
}
}
} catch (ShareImage::cancelled &) {
std::cout << "Cancelled!" << std::endl;
}
share_image.cancel();
}
} // Namespace
int main(int argc, char *argv[])
{
unsigned int deviceCount = 1;
unsigned int cameraScale = 1; // 640x480
bool saveVideo = false;
// Read the command line options
if (!getOptions(argc, argv, deviceCount, saveVideo)) {
return (-1);
}
std::vector<vpV4l2Grabber *> grabbers;
const unsigned int offsetX = 100, offsetY = 100;
for (unsigned int devicedId = 0; devicedId < deviceCount; devicedId++) {
try {
vpV4l2Grabber *pGrabber = new vpV4l2Grabber;
std::stringstream ss;
ss << "/dev/video" << devicedId;
pGrabber->setDevice(ss.str());
pGrabber->setScale(cameraScale);
grabbers.push_back(pGrabber);
} catch (const vpException &e) {
std::cerr << "Exception: " << e.what() << std::endl;
}
}
std::cout << "Grabbers: " << grabbers.size() << std::endl;
std::vector<ShareImage> share_images(grabbers.size());
std::vector<std::thread> capture_threads;
std::vector<std::thread> display_threads;
// Synchronized queues for each camera stream
std::vector<FrameQueue> save_queues(grabbers.size());
std::vector<StorageWorker> storages;
std::vector<std::thread> storage_threads;
std::string parent_directory = vpTime::getDateTime("%Y-%m-%d_%H.%M.%S");
for (size_t deviceId = 0; deviceId < grabbers.size(); deviceId++) {
// Start the capture thread for the current camera stream
capture_threads.emplace_back(capture, grabbers[deviceId], std::ref(share_images[deviceId]));
int win_x = deviceId * offsetX, win_y = deviceId * offsetY;
// Start the display thread for the current camera stream
display_threads.emplace_back(display, grabbers[deviceId]->getWidth(), grabbers[deviceId]->getHeight(), win_x, win_y,
deviceId, std::ref(share_images[deviceId]), std::ref(save_queues[deviceId]),
saveVideo);
if (saveVideo) {
std::stringstream ss;
ss << parent_directory << "/Camera_Stream" << deviceId;
std::cout << "Create directory: " << ss.str() << std::endl;
ss << "/%06d.png";
std::string filename = ss.str();
storages.emplace_back(std::ref(save_queues[deviceId]), std::cref(filename), grabbers[deviceId]->getWidth(),
grabbers[deviceId]->getHeight());
}
}
if (saveVideo) {
for (auto &s : storages) {
// Start the storage thread for the current camera stream
storage_threads.emplace_back(&StorageWorker::run, &s);
}
}
// Join all the worker threads, waiting for them to finish
for (auto &ct : capture_threads) {
ct.join();
}
for (auto &dt : display_threads) {
dt.join();
}
// Clean first the grabbers to avoid camera problems when cancelling the
// storage threads in the terminal
for (auto &g : grabbers) {
delete g;
}
if (saveVideo) {
std::cout << "\nWaiting for finishing thread to write images..." << std::endl;
}
// We're done reading, cancel all the queues
for (auto &qu : save_queues) {
qu.cancel();
}
// Join all the worker threads, waiting for them to finish
for (auto &st : storage_threads) {
st.join();
}
return EXIT_SUCCESS;
}
#else
#if !(defined(VISP_HAVE_X11) || defined(VISP_HAVE_GTK))
int main()
{
std::cout << "You do not have X11, or GTK functionalities to display images..." << std::endl;
std::cout << "Tip if you are on a unix-like system:" << std::endl;
std::cout << "- Install X11, configure again ViSP using cmake and build again this example" << std::endl;
std::cout << "Tip if you are on a windows-like system:" << std::endl;
std::cout << "- Install GTK, configure again ViSP using cmake and build again this example" << std::endl;
return EXIT_SUCCESS;
}
#elif !defined(VISP_HAVE_V4L2)
int main()
{
std::cout << "You do not have Video 4 Linux 2 functionality enabled" << std::endl;
std::cout << "Tip if you are on a unix-like system:" << std::endl;
std::cout << "- Install libv4l2, configure again ViSP using cmake and build again this example" << std::endl;
return EXIT_SUCCESS;
}
#else
int main()
{
std::cout << "You do not build ViSP with C++11 compiler flag" << std::endl;
std::cout << "Tip:" << std::endl;
std::cout << "- Configure ViSP again using cmake -DUSE_CPP11=ON, and build again this example" << std::endl;
return EXIT_SUCCESS;
}
#endif
#endif