Merge PR #203 from felipe-m/fps

Include fps analysis in verilator simulation

sim_fpga/tutorial/tut03/readme.md

@@ -24,6 +24,14 @@ The graphical interface allows debugging more easily. For example, the next scre
 
 ![2nd camera frame](imgs/camera_proc_06_sm.png)
 
+## Frames per second (FPS)
+
+Information about the frames per second processed is at the bottom, it includes two methods for calculating it.
+At this frame size (160x120) it gets around 6 fps, in [tutorial 4](../tut04) the frame size is 640x480, and the frame rate is around 2 fps.
+
+![Screenshot with frame period and fps](imgs/fps.jpg)
+
+
 
 
 

sim_fpga/tutorial/tut03/src/main.cpp

@@ -10,6 +10,7 @@
 #include <SDL_opengl.h>
 #include <assert.h>
 #include <stdio.h>
+#include <chrono> // to measure fps
 
 #include <opencv2/opencv.hpp>
 #include <opencv2/core.hpp>
@@ -437,14 +438,22 @@ int main(int argc, char **argv) {
   // -------------------- Init Video Input 
   cv::Mat input_feed;
   cv::Mat resized_input_feed;
+  // start default camera
   cv::VideoCapture cap(0);
 
+  double timed_fps;
+  unsigned int millis_elapsed = 0;
+
+  // get opencv frame per seconds (FPS)
+  double cam_fps = cap.get(cv::CAP_PROP_FPS);
 
   if (!cap.isOpened()) {
       std::cout << "cannot open camera";
   }
 
-  cap >> input_feed;
+  auto time_capture = std::chrono::high_resolution_clock::now();
+  auto old_time_capture = std::chrono::high_resolution_clock::now();
+  cap >> input_feed; // capture image from camera
   cv::resize(input_feed,resized_input_feed,cv::Size(IMG_COLS,IMG_ROWS),cv::INTER_LINEAR);
 
   // init dut, tracing and sim elements
@@ -529,7 +538,9 @@ int main(int argc, char **argv) {
         step_n_cycles = frames_per_iteration * IMG_PXLS;
       }
 
-      cap >> input_feed;
+      old_time_capture = time_capture; // save old capture
+      time_capture = std::chrono::high_resolution_clock::now(); // new time capture
+      cap >> input_feed; // capture image from camera
       cv::resize(input_feed,resized_input_feed,cv::Size(IMG_COLS,IMG_ROWS),cv::INTER_LINEAR);
 
 //      assert(input_feed.channels() == 3 && input_feed.cols == cols &&
@@ -680,8 +691,17 @@ int main(int argc, char **argv) {
       ImGui::Text("Centroid: 0x%x - Proximity: %i", centroid, proximity);
       //ImGui::SameLine();
 
+
+      // the 1st capture will be wrong, but just only the first
+      auto elapsed = std::chrono::duration_cast<std::chrono::milliseconds>(
+                                            time_capture - old_time_capture);
+      millis_elapsed = elapsed.count();
+      timed_fps = 1000.0 / millis_elapsed;
+      ImGui::Text("Timed %i ms (%.1f FPS)", millis_elapsed, timed_fps);
       ImGui::Text("Application average %.3f ms/frame (%.1f FPS)",
                   1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
+
+      ImGui::Text("Maximum camera fps %.1f", cam_fps);
       ImGui::End();
     }
 

sim_fpga/tutorial/tut04/readme.md

@@ -7,6 +7,14 @@ The color processing is the same as in tutorial 3 and 2 (only changing some gene
 
 * [../../../phys_fpga/ulx3s/apio/ov7670x2_colorcentroid_160x120/color_proc.v](../../../phys_fpga/ulx3s/apio/ov7670x2_colorcentroid_160x120/color_proc.v)
 
+Frames per second has been included, they can be seen at the bottom of the window.
+It includes two measurement methods and the maximum fps reported by opencv.
+With this resolution around 2 frames per second can be achieved.
+
+Note that in [tutorial 3](../tut03) the frame size is 160x120, and the frame rate was above 6 fps.
+
+![Screenshot with frame period and fps](imgs/fps_sm.jpg)
+
 The rest is the same as in tutorial 3.
 
 

sim_fpga/tutorial/tut04/src/main.cpp

@@ -9,6 +9,7 @@
 #include <SDL_opengl.h>
 #include <assert.h>
 #include <stdio.h>
+#include <chrono> // to measure fps
 
 #include <opencv2/opencv.hpp>
 #include <opencv2/core.hpp>
@@ -435,14 +436,22 @@ int main(int argc, char **argv) {
   // -------------------- Init Video Input 
   cv::Mat input_feed;
   cv::Mat resized_input_feed;
+  // start default camera
   cv::VideoCapture cap(0);
 
+  double timed_fps;
+  unsigned int millis_elapsed = 0;
+
+  // get opencv frame per seconds (FPS)
+  double cam_fps = cap.get(cv::CAP_PROP_FPS);
 
   if (!cap.isOpened()) {
       std::cout << "cannot open camera";
   }
 
-  cap >> input_feed;
+  auto time_capture = std::chrono::high_resolution_clock::now();
+  auto old_time_capture = std::chrono::high_resolution_clock::now();
+  cap >> input_feed; // capture image from camera
   cv::resize(input_feed,resized_input_feed,cv::Size(IMG_COLS,IMG_ROWS),cv::INTER_LINEAR);
 
   // init dut, tracing and sim elements
@@ -527,7 +536,9 @@ int main(int argc, char **argv) {
         step_n_cycles = frames_per_iteration * IMG_PXLS;
       }
 
-      cap >> input_feed;
+      old_time_capture = time_capture; // save old capture
+      time_capture = std::chrono::high_resolution_clock::now(); // new time capture
+      cap >> input_feed; // capture image from camera
       cv::resize(input_feed,resized_input_feed,cv::Size(IMG_COLS,IMG_ROWS),cv::INTER_LINEAR);
 
 //      assert(input_feed.channels() == 3 && input_feed.cols == cols &&
@@ -678,8 +689,18 @@ int main(int argc, char **argv) {
       ImGui::Text("Centroid: 0x%x - Proximity: %i", centroid, proximity);
       //ImGui::SameLine();
 
+      // the 1st capture will be wrong, but just only the first
+      auto elapsed = std::chrono::duration_cast<std::chrono::milliseconds>(
+                                            time_capture - old_time_capture);
+      millis_elapsed = elapsed.count();
+      timed_fps = 1000.0 / millis_elapsed;
+      ImGui::Text("Timed %i ms (%.1f FPS)", millis_elapsed, timed_fps);
+
       ImGui::Text("Application average %.3f ms/frame (%.1f FPS)",
                   1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
+
+      ImGui::Text("Maximum camera fps %.1f", cam_fps);
+
       ImGui::End();
     }