ffprobe: show packet duration in frame

doc/ffprobe.xsd

@@ -53,6 +53,8 @@
       <xsd:attribute name="pkt_pts_time"  type="xsd:float"/>
       <xsd:attribute name="pkt_dts"       type="xsd:long" />
       <xsd:attribute name="pkt_dts_time"  type="xsd:float"/>
+      <xsd:attribute name="pkt_duration"  type="xsd:long" />
+      <xsd:attribute name="pkt_duration_time" type="xsd:float"/>
       <xsd:attribute name="pkt_pos"       type="xsd:long" />
 
       <!-- audio attributes -->

ffprobe.c

@@ -1567,6 +1567,8 @@ static void show_frame(WriterContext *w, AVFrame *frame, AVStream *stream)
     print_time("pkt_pts_time",          frame->pkt_pts, &stream->time_base);
     print_ts  ("pkt_dts",               frame->pkt_dts);
     print_time("pkt_dts_time",          frame->pkt_dts, &stream->time_base);
+    print_duration_ts  ("pkt_duration",      frame->pkt_duration);
+    print_duration_time("pkt_duration_time", frame->pkt_duration, &stream->time_base);
     if (frame->pkt_pos != -1) print_fmt    ("pkt_pos", "%"PRId64, frame->pkt_pos);
     else                      print_str_opt("pkt_pos", "N/A");