Get real exposure time and draw

include/mynteye/types.h

@@ -368,7 +368,7 @@ struct MYNTEYE_API ImgData {
   std::uint16_t frame_id;
   /** Image timestamp in 0.01ms */
   std::uint32_t timestamp;
-  /** Image exposure time in 0.01ms */
+  /** Image exposure time, virtual value in [1, 480] */
   std::uint16_t exposure_time;
 
   void Reset() {

include/mynteye/utils.h

@@ -30,6 +30,15 @@ MYNTEYE_API std::shared_ptr<Device> select();
 
 }  // namespace device
 
+namespace utils {
+
+/** Get real exposure time in ms from virtual value, according to its frame rate
+ */
+MYNTEYE_API float get_real_exposure_time(
+    std::int32_t frame_rate, std::uint16_t exposure_time);
+
+}  // namespace utils
+
 MYNTEYE_END_NAMESPACE
 
 #endif  // MYNTEYE_UTILS_H_ NOLINT

samples/tutorials/control/auto_exposure.cc

@@ -43,7 +43,7 @@ int main(int argc, char *argv[]) {
 
   api->Start(Source::VIDEO_STREAMING);
 
-  CVPainter painter;
+  CVPainter painter(api->GetOptionValue(Option::FRAME_RATE));
 
   cv::namedWindow("frame");
 

samples/tutorials/control/manual_exposure.cc

@@ -41,7 +41,7 @@ int main(int argc, char *argv[]) {
 
   api->Start(Source::VIDEO_STREAMING);
 
-  CVPainter painter;
+  CVPainter painter(api->GetOptionValue(Option::FRAME_RATE));
 
   cv::namedWindow("frame");
 

samples/tutorials/util/cv_painter.cc

@@ -22,6 +22,8 @@
 #include <memory>
 #include <utility>
 
+#include "mynteye/utils.h"
+
 #define FONT_FACE cv::FONT_HERSHEY_PLAIN
 #define FONT_SCALE 1
 #define FONT_COLOR cv::Scalar(255, 255, 255)
@@ -32,8 +34,10 @@ namespace {
 std::shared_ptr<std::ios> NewFormat(int width, int prec, char fillch = ' ') {
   auto fmt = std::make_shared<std::ios>(nullptr);
   fmt->setf(std::ios::fixed);
-  fmt->width(std::move(width));
+  if (width > 0)
-  fmt->precision(std::move(prec));
+    fmt->width(std::move(width));
+  if (prec > 0)
+    fmt->precision(std::move(prec));
   fmt->fill(std::move(fillch));
   return fmt;
 }
@@ -53,7 +57,8 @@ std::ostream &operator<<(
   return os;
 }
 
-CVPainter::CVPainter() {
+CVPainter::CVPainter(std::int32_t frame_rate)
+    : frame_rate_(std::move(frame_rate)) {
   VLOG(2) << __func__;
 }
 
@@ -74,9 +79,18 @@ cv::Rect CVPainter::DrawImgData(
   if (gravity == BOTTOM_LEFT || gravity == BOTTOM_RIGHT)
     sign = -1;
 
+  static auto fmt_time = NewFormat(0, 2);
+
   std::ostringstream ss;
-  ss << "frame_id: " << data.frame_id << ", stamp: " << data.timestamp
+  ss << "frame_id: " << data.frame_id;
-     << ", expo: " << data.exposure_time;
+  ss << ", stamp: " << fmt_time << (0.01f * data.timestamp);  // ms
+  ss << ", expo: ";
+  if (frame_rate_ == 0) {
+    ss << data.exposure_time;
+  } else {
+    ss << fmt_time << mynteye::utils::get_real_exposure_time(
+                          frame_rate_, data.exposure_time);
+  }
   cv::Rect rect_i = DrawText(img, ss.str(), gravity, 5);
 
   Clear(ss) << "size: " << img.cols << "x" << img.rows;

samples/tutorials/util/cv_painter.h

@@ -30,7 +30,7 @@ class CVPainter {
     BOTTOM_RIGHT
   } gravity_t;
 
-  CVPainter();
+  explicit CVPainter(std::int32_t frame_rate = 0);
   ~CVPainter();
 
   cv::Rect DrawSize(const cv::Mat &img, const gravity_t &gravity = TOP_LEFT);
@@ -45,6 +45,9 @@ class CVPainter {
       const cv::Mat &img, const std::string &text,
       const gravity_t &gravity = TOP_LEFT, const int &margin = 5,
       const int &offset_x = 0, const int &offset_y = 0);
+
+ private:
+  std::int32_t frame_rate_;
 };
 
 #endif  // MYNTEYE_TUTORIALS_CV_PAINTER_H_ NOLINT

src/public/utils.cc

@@ -60,4 +60,52 @@ std::shared_ptr<Device> select() {
 
 }  // namespace device
 
+namespace utils {
+
+float get_real_exposure_time(
+    std::int32_t frame_rate, std::uint16_t exposure_time) {
+  float real_max = 0;
+  switch (frame_rate) {
+    case 10:
+      real_max = 18;
+      break;
+    case 15:
+      real_max = 18;
+      break;
+    case 20:
+      real_max = 18;
+      break;
+    case 25:
+      real_max = 18;
+      break;
+    case 30:
+      real_max = 18;
+      break;
+    case 35:
+      real_max = 18;
+      break;
+    case 40:
+      real_max = 18;
+      break;
+    case 45:
+      real_max = 18;
+      break;
+    case 50:
+      real_max = 17;
+      break;
+    case 55:
+      real_max = 16.325;
+      break;
+    case 60:
+      real_max = 15;
+      break;
+    default:
+      LOG(ERROR) << "Invalid frame rate: " << frame_rate;
+      return exposure_time;
+  }
+  return exposure_time * real_max / 480.f;
+}
+
+}  // namespace utils
+
 MYNTEYE_END_NAMESPACE