ffprobe: print codec timecode if available.

ffprobe.c

@@ -993,6 +993,17 @@ static void show_stream(WriterContext *w, AVFormatContext *fmt_ctx, int stream_i
             if (s) print_str    ("pix_fmt", s);
             else   print_str_opt("pix_fmt", "unknown");
             print_int("level",   dec_ctx->level);
+            if (dec_ctx->timecode_frame_start >= 0) {
+                uint32_t tc = dec_ctx->timecode_frame_start;
+                print_fmt("timecode", "%02d:%02d:%02d%c%02d",
+                          tc>>19 & 0x1f,              // hours
+                          tc>>13 & 0x3f,              // minutes
+                          tc>>6  & 0x3f,              // seconds
+                          tc     & 1<<24 ? ';' : ':', // drop
+                          tc     & 0x3f);             // frames
+            } else {
+                print_str_opt("timecode", "N/A");
+            }
             break;
 
         case AVMEDIA_TYPE_AUDIO: