Improved speed of yolo_console_dll.cpp

src/yolo_console_dll.cpp

@@ -5,6 +5,8 @@
 #include <fstream>
 #include <thread>
 #include <atomic>
+#include <mutex>              // std::mutex, std::unique_lock
+#include <condition_variable> // std::condition_variable
 
 #define OPENCV
 
@@ -24,7 +26,7 @@
 
 
 void draw_boxes(cv::Mat mat_img, std::vector<bbox_t> result_vec, std::vector<std::string> obj_names, 
-	unsigned int wait_msec = 0, int current_fps = -1)
+	unsigned int wait_msec = 0, int current_det_fps = -1, int current_cap_fps = -1)
 {
 	for (auto &i : result_vec) {
 		cv::Scalar color(60, 160, 260);
@@ -40,15 +42,17 @@ void draw_boxes(cv::Mat mat_img, std::vector<bbox_t> result_vec, std::vector<std
 			putText(mat_img, obj_name, cv::Point2f(i.x, i.y - 10), cv::FONT_HERSHEY_COMPLEX_SMALL, 1.2, cv::Scalar(0, 0, 0), 2);
 		}
 	}
-	if(current_fps >= 0)
+	if (current_det_fps >= 0 && current_cap_fps >= 0) {
-		putText(mat_img, "FPS: " + std::to_string(current_fps), cv::Point2f(10, 20), cv::FONT_HERSHEY_COMPLEX_SMALL, 1.2, cv::Scalar(50, 255, 0), 2);
+		std::string fps_str = "FPS detection: " + std::to_string(current_det_fps) + "   FPS capture: " + std::to_string(current_cap_fps);
+		putText(mat_img, fps_str, cv::Point2f(10, 20), cv::FONT_HERSHEY_COMPLEX_SMALL, 1.2, cv::Scalar(50, 255, 0), 2);
+	}
 	cv::imshow("window name", mat_img);
 	cv::waitKey(wait_msec);
 }
 #endif	// OPENCV
 
 
-void show_result(std::vector<bbox_t> const result_vec, std::vector<std::string> const obj_names) {
+void show_console_result(std::vector<bbox_t> const result_vec, std::vector<std::string> const obj_names) {
 	for (auto &i : result_vec) {
 		if (obj_names.size() > i.obj_id) std::cout << obj_names[i.obj_id] << " - ";
 		std::cout << "obj_id = " << i.obj_id << ",  x = " << i.x << ", y = " << i.y 
@@ -91,41 +95,91 @@ int main(int argc, char *argv[])
 			if (file_ext == "avi" || file_ext == "mp4" || file_ext == "mjpg" || file_ext == "mov" || 	// video file
 				protocol == "rtsp://" || protocol == "http://" || protocol == "https:/")	// video network stream
 			{
-				cv::Mat frame, prev_frame, det_frame;
+				cv::Mat cap_frame, cur_frame, det_frame, write_frame;
 				std::vector<bbox_t> result_vec, thread_result_vec;
 				detector.nms = 0.02;	// comment it - if track_id is not required
-				std::thread td([]() {});
+				std::atomic<bool> consumed, videowrite_ready;
-				std::atomic<int> ready_flag;
+				consumed = true;
-				ready_flag = true;
+				videowrite_ready = true;
+				std::atomic<int> fps_det_counter, fps_cap_counter;
+				fps_det_counter = 0;
+				fps_cap_counter = 0;
+				int current_det_fps = 0, current_cap_fps = 0;
+				std::thread t_detect, t_cap, t_videowrite;
+				std::mutex mtx;
+				std::condition_variable cv;
 				std::chrono::steady_clock::time_point steady_start, steady_end;
-				int fps_counter = 0, current_fps = 0;
+				cv::VideoCapture cap(filename); cap >> cur_frame;
 				cv::VideoWriter output_video;
-				for (cv::VideoCapture cap(filename); cap >> frame, cap.isOpened();) {
+				if (save_output_videofile)
-					if(!output_video.isOpened() && save_output_videofile)
+					output_video.open(out_videofile, CV_FOURCC('D', 'I', 'V', 'X'), cap.get(CV_CAP_PROP_FPS), cur_frame.size(), true);
-						output_video.open(out_videofile, CV_FOURCC('D','I','V','X'), cap.get(CV_CAP_PROP_FPS), frame.size(), true);
+
-					if (ready_flag || (protocol != "rtsp://" && protocol != "http://" && protocol != "https:/")) {
+				while (!cur_frame.empty()) {
-						td.join();
+					if (t_cap.joinable()) {
-						++fps_counter;
+						t_cap.join();
-						ready_flag = false;
+						++fps_cap_counter;
+						cur_frame = cap_frame.clone();
+					}
+					t_cap = std::thread([&]() { cap >> cap_frame; });
+
+					// swap result and input-frame
+					if(consumed)
+					{
+						std::unique_lock<std::mutex> lock(mtx);
+						cur_frame.copyTo(det_frame);
 						result_vec = thread_result_vec;
 						result_vec = detector.tracking(result_vec);	// comment it - if track_id is not required
-						det_frame = frame.clone();						
+						consumed = false;
-						td = std::thread([&]() { thread_result_vec = detector.detect(det_frame, 0.24, true); ready_flag = true; });
 					}
-					if (!prev_frame.empty()) {	
+					// launch thread once
+					if (!t_detect.joinable()) {
+						t_detect = std::thread([&]() {
+							cv::Mat current_mat = det_frame.clone();
+							consumed = true;
+							while (!current_mat.empty()) {
+								auto result = detector.detect(current_mat, 0.24, true);
+								++fps_det_counter;
+								std::unique_lock<std::mutex> lock(mtx);
+								thread_result_vec = result;
+								current_mat = det_frame.clone();
+								consumed = true;
+								cv.notify_all();
+							}
+						});
+					}
+
+					if (!cur_frame.empty()) {
 						steady_end = std::chrono::steady_clock::now();
 						if (std::chrono::duration<double>(steady_end - steady_start).count() >= 1) {
-							current_fps = fps_counter;
+							current_det_fps = fps_det_counter;
+							current_cap_fps = fps_cap_counter;
 							steady_start = steady_end;
-							fps_counter = 0;
+							fps_det_counter = 0;
+							fps_cap_counter = 0;
+						}
+						draw_boxes(cur_frame, result_vec, obj_names, 3, current_det_fps, current_cap_fps);
+						//show_console_result(result_vec, obj_names);
+
+						if (output_video.isOpened() && videowrite_ready) {
+							if (t_videowrite.joinable()) t_videowrite.join();
+							write_frame = cur_frame.clone();
+							videowrite_ready = false;
+							t_videowrite = std::thread([&]() { 
+								 output_video << write_frame; videowrite_ready = true;
+							});
 						}
-						draw_boxes(prev_frame, result_vec, obj_names, 3, current_fps);
-						show_result(result_vec, obj_names);
-						if (output_video.isOpened())
-							output_video << prev_frame;
 					}
-					prev_frame = frame.clone();					
+
+					// wait detection result for video-file only (not for net-cam)
+					if (protocol != "rtsp://" && protocol != "http://" && protocol != "https:/") {
+						std::unique_lock<std::mutex> lock(mtx);
+						while (!consumed) cv.wait(lock);
+					}
 				}
+				if (t_cap.joinable()) t_cap.join();
+				if (t_detect.joinable()) t_detect.join();
+				if (t_videowrite.joinable()) t_videowrite.join();
+				std::cout << "Video ended \n";
 			}
 			else if (file_ext == "txt") {	// list of image files
 				std::ifstream file(filename);
@@ -135,7 +189,7 @@ int main(int argc, char *argv[])
 						std::cout << line << std::endl;
 						cv::Mat mat_img = cv::imread(line);
 						std::vector<bbox_t> result_vec = detector.detect(mat_img);
-						show_result(result_vec, obj_names);
+						show_console_result(result_vec, obj_names);
 						//draw_boxes(mat_img, result_vec, obj_names);
 						//cv::imwrite("res_" + line, mat_img);
 					}
@@ -146,7 +200,7 @@ int main(int argc, char *argv[])
 				std::vector<bbox_t> result_vec = detector.detect(mat_img);
 				result_vec = detector.tracking(result_vec);	// comment it - if track_id is not required
 				draw_boxes(mat_img, result_vec, obj_names);
-				show_result(result_vec, obj_names);
+				show_console_result(result_vec, obj_names);
 			}
 #else
 			//std::vector<bbox_t> result_vec = detector.detect(filename);