Fix: Correct calculation of training time remaininig when resume training (src/classifier.c)

Output training time remaining to console if darknet is not compiled with OpenCV

src/classifier.c

@@ -136,7 +136,7 @@ void train_classifier(char *datacfg, char *cfgfile, char *weightfile, int *gpus,
     float topk = 0;
 
     int count = 0;
-    double start, time_remaining, avg_t_minus_1, avg_t, alpha = 0.01;
+    double start, time_remaining, avg_time = -1, alpha_time = 0.01;
     start = what_time_is_it_now();
 
     while(get_current_batch(net) < net.max_batches || net.max_batches == 0){
@@ -187,18 +187,14 @@ void train_classifier(char *datacfg, char *cfgfile, char *weightfile, int *gpus,
             draw_precision = 1;
         }
 
-        printf("%d, %.3f: %f, %f avg, %f rate, %lf seconds, %ld images\n", get_current_batch(net), (float)(*net.seen)/ train_images_num, loss, avg_loss, get_current_rate(net), sec(clock()-time), *net.seen);
-#ifdef OPENCV
         time_remaining = (net.max_batches - i)*(what_time_is_it_now() - start) / 60 / 60;
-        if (i > 1){  // ignore the first iteration
-            if (i == 2){
-                avg_t_minus_1 = time_remaining;
-            }
-            avg_t = alpha * time_remaining + (1 - alpha) * avg_t_minus_1;
-            avg_t_minus_1 = avg_t;
-        }
-        if (!dontuse_opencv) draw_train_loss(windows_name, img, img_size, avg_loss, max_img_loss, i, net.max_batches, topk, draw_precision, topk_buff, dont_show, mjpeg_port, avg_t);
+        // set initial value, even if resume training from 10000 iteration
+        if (avg_time < 0) avg_time = time_remaining;
+        else avg_time = alpha_time * time_remaining + (1 -  alpha_time) * avg_time;
         start = what_time_is_it_now();
+        printf("%d, %.3f: %f, %f avg, %f rate, %lf seconds, %ld images, %f time left\n", get_current_batch(net), (float)(*net.seen)/ train_images_num, loss, avg_loss, get_current_rate(net), sec(clock()-time), *net.seen, avg_time);
+#ifdef OPENCV
+        if (!dontuse_opencv) draw_train_loss(windows_name, img, img_size, avg_loss, max_img_loss, i, net.max_batches, topk, draw_precision, topk_buff, dont_show, mjpeg_port, avg_time);
 #endif  // OPENCV
 
         if (i >= (iter_save + 1000)) {