ffmpeg: report max time of unfinished streams in stats.

Eliminating finished streams avoids the progress stopping
with the first stream.
Using the max instead of the min avoids the progress stopping
with gaps in sparse streams (subtitles).
Negligible change for normal circumstances.

ffmpeg.c

@@ -1059,7 +1059,7 @@ static void print_report(int is_last_report, int64_t timer_start, int64_t cur_ti
     AVCodecContext *enc;
     int frame_number, vid, i;
     double bitrate;
-    int64_t pts = INT64_MAX;
+    int64_t pts = INT64_MIN;
     static int64_t last_time = -1;
     static int qp_histogram[52];
     int hours, mins, secs, us;
@@ -1154,8 +1154,9 @@ static void print_report(int is_last_report, int64_t timer_start, int64_t cur_ti
             vid = 1;
         }
         /* compute min output value */
-        pts = FFMIN(pts, av_rescale_q(ost->st->pts.val,
-                                      ost->st->time_base, AV_TIME_BASE_Q));
+        if (!ost->finished && ost->st->pts.val != AV_NOPTS_VALUE)
+            pts = FFMAX(pts, av_rescale_q(ost->st->pts.val,
+                                          ost->st->time_base, AV_TIME_BASE_Q));
     }
 
     secs = pts / AV_TIME_BASE;