optimize image get

CMakeLists.txt

@@ -285,6 +285,9 @@ target_link_libraries(EvalFpsOnVideo sv_world)
 add_executable(GimbalTest samples/test/gimbal_test.cpp)
 target_link_libraries(GimbalTest sv_world)
 
+add_executable(CameraTest samples/test/camera_fps_test.cpp)
+target_link_libraries(CameraTest sv_world)
+
 add_executable(EvalModelOnCocoVal samples/test/eval_mAP_on_coco_val/eval_mAP_on_coco_val.cpp)
 target_link_libraries(EvalModelOnCocoVal sv_world)
 

include/sv_video_base.h

@@ -12,6 +12,9 @@
 #include <arpa/inet.h>
 #include <netinet/in.h>  // for sockaddr_in
 
+#include <mutex>
+#include <condition_variable>
+
 #define SV_RAD2DEG 57.2957795
 // #define X86_PLATFORM
 // #define JETSON_PLATFORM
@@ -358,7 +361,15 @@ protected:
   void _run();
 
   bool _is_running;
+
+// new mutex
+  std::mutex _frame_mutex;
+  std::condition_variable_any _frame_empty;
+
+//old flag
   bool _is_updated;
+
+
   std::thread _tt;
   cv::VideoCapture _cap;
   cv::Mat _frame;
@@ -397,3 +408,4 @@ void list_dir(std::string dir, std::vector<std::string>& files, std::string suff
 
 }
 #endif
+

samples/test/camera_fps_test.cpp

@@ -0,0 +1,29 @@
+
+#include <sv_world.h>
+#include <iostream>
+#include <string>
+#include <chrono>
+
+int main(int argc, char *argv[])
+{
+    sv::Camera cap;
+    cap.setIp(argv[1]);
+    cap.open(sv::CameraType::G1);
+    cap.setWH(1280, 720);
+    cap.setFps(30);
+
+    cv::Mat img;
+
+    while (1)
+    {
+        auto time1 = std::chrono::duration_cast<std::chrono::nanoseconds>(std::chrono::system_clock::now().time_since_epoch()).count();
+        for (uint16_t i = 0; i < 120; i++)
+        {
+            cap.read(img);
+        }
+        auto time2 = std::chrono::duration_cast<std::chrono::nanoseconds>(std::chrono::system_clock::now().time_since_epoch()).count();
+        auto Ts = time2 - time1;
+        std::cout << "read 120 count;Ts = " << Ts / (1000) << "us" << std::endl;
+        std::cout << "average FPS = " << (1000 * 1000 * 1000) / (Ts / 120) << std::endl;
+    }
+}

video_io/sv_video_base.cpp

@@ -1103,13 +1103,37 @@ void CameraBase::_run()
 {
   while (this->_is_running && this->_cap.isOpened())
   {
-    this->_cap >> this->_frame;
+    // this->_cap >> this->_frame;
-    this->_is_updated = true;
+    // this->_is_updated = true;
-    std::this_thread::sleep_for(std::chrono::milliseconds(2));
+    // std::this_thread::sleep_for(std::chrono::milliseconds(2));
+
+    if(this->_cap.grab())
+    {
+      std::lock_guard<std::mutex> locker(this->_frame_mutex);
+      this->_cap.retrieve(this->_frame);      
+      this->_frame_empty.notify_all();
+    }
+    std::this_thread::sleep_for(std::chrono::milliseconds(1));
   }
 }
 bool CameraBase::read(cv::Mat& image)
 {
+  bool ret = false;
+  if (this->_type == CameraType::WEBCAM || this->_type == CameraType::G1 || this->_type == CameraType::MIPI)
+  {
+    std::lock_guard<std::mutex> locker(this->_frame_mutex);
+    if(this->_frame_empty.wait_for(this->_frame_mutex,std::chrono::milliseconds(2000)) == std::cv_status::no_timeout)
+    {
+      this->_frame.copyTo(image);
+      ret = true;
+    }
+    else
+    {
+      throw std::runtime_error("SpireCV (101) Camera cannot OPEN, check CAMERA_ID!");
+    }
+  }
+  return ret;
+
   if (this->_type == CameraType::WEBCAM || this->_type == CameraType::G1 || this->_type == CameraType::MIPI)
   {
     int n_try = 0;