mpegts: only reopen pmt_cb filter if its different from the previous.

Fixes Ticket2632

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/mpegts.c

@@ -1625,12 +1625,18 @@ static void pat_cb(MpegTSFilter *filter, const uint8_t *section, int section_len
         if (sid == 0x0000) {
             /* NIT info */
         } else {
+            MpegTSFilter *fil = ts->pids[pmt_pid];
             program = av_new_program(ts->stream, sid);
             program->program_num = sid;
             program->pmt_pid = pmt_pid;
-            if (ts->pids[pmt_pid])
-                mpegts_close_filter(ts, ts->pids[pmt_pid]);
-            mpegts_open_section_filter(ts, pmt_pid, pmt_cb, ts, 1);
+            if (fil)
+                if (   fil->type != MPEGTS_SECTION
+                    || fil->pid != pmt_pid
+                    || fil->u.section_filter.section_cb != pmt_cb)
+                    mpegts_close_filter(ts, ts->pids[pmt_pid]);
+
+            if (!ts->pids[pmt_pid])
+                mpegts_open_section_filter(ts, pmt_pid, pmt_cb, ts, 1);
             add_pat_entry(ts, sid);
             add_pid_to_pmt(ts, sid, 0); //add pat pid to program
             add_pid_to_pmt(ts, sid, pmt_pid);