ffmpeg: show fps more accurately when it is small.

ffmpeg.c

@@ -1715,11 +1715,12 @@ static void print_report(OutputFile *output_files,
             snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), "q=%2.1f ", q);
         }
         if (!vid && enc->codec_type == AVMEDIA_TYPE_VIDEO) {
-            float t = (cur_time-timer_start) / 1000000.0;
+            float fps, t = (cur_time-timer_start) / 1000000.0;
 
             frame_number = ost->frame_number;
-            snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), "frame=%5d fps=%3d q=%3.1f ",
-                     frame_number, (t > 1) ? (int)(frame_number / t + 0.5) : 0, q);
+            fps = t > 1 ? frame_number / t : 0;
+            snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), "frame=%5d fps=%3.*f q=%3.1f ",
+                     frame_number, fps < 9.95, fps, q);
             if (is_last_report)
                 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), "L");
             if (qp_hist) {