avformat/mpegtsenc: move some code around and simplify a bit

PCR does not need to be recalcualted for CBR when inserting a NULL or PCR only
packet.
Signed-off-by: Marton Balint <cus@passwd.hu>

libavformat/mpegtsenc.c

@@ -1221,16 +1221,7 @@ static void mpegts_write_pes(AVFormatContext *s, AVStream *st,
                 }
                 ts->next_pcr = next_pcr;
             }
-        } else if (ts_st->pcr_period && dts != AV_NOPTS_VALUE) {
-            pcr = (dts - delay) * 300;
-            if (pcr - ts_st->last_pcr >= ts_st->pcr_period && is_start) {
-                ts_st->last_pcr = FFMAX(pcr - ts_st->pcr_period, ts_st->last_pcr + ts_st->pcr_period);
-                write_pcr = 1;
-            }
-        }
-
-        if (ts->mux_rate > 1 && dts != AV_NOPTS_VALUE &&
-            (dts - get_pcr(ts, s->pb) / 300) > delay) {
+            if (dts != AV_NOPTS_VALUE && (dts - pcr / 300) > delay) {
                 /* pcr insert gets priority over null packet insert */
                 if (write_pcr)
                     mpegts_insert_pcr_only(s, st);
@@ -1239,6 +1230,13 @@ static void mpegts_write_pes(AVFormatContext *s, AVStream *st,
                 /* recalculate write_pcr and possibly retransmit si_info */
                 continue;
             }
+        } else if (ts_st->pcr_period && dts != AV_NOPTS_VALUE) {
+            pcr = (dts - delay) * 300;
+            if (pcr - ts_st->last_pcr >= ts_st->pcr_period && is_start) {
+                ts_st->last_pcr = FFMAX(pcr - ts_st->pcr_period, ts_st->last_pcr + ts_st->pcr_period);
+                write_pcr = 1;
+            }
+        }
 
         /* prepare packet header */
         q    = buf;