avformat/mux: Use av_packet_rescale_ts

ff_write_chained essentially duplicated the functionality of
av_packet_rescale_ts. This has been changed.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavformat/mux.c

@@ -1323,18 +1323,10 @@ int ff_write_chained(AVFormatContext *dst, int dst_stream, AVPacket *pkt,
 
     local_pkt = *pkt;
     local_pkt.stream_index = dst_stream;
-    if (pkt->pts != AV_NOPTS_VALUE)
-        local_pkt.pts = av_rescale_q(pkt->pts,
-                                     src->streams[pkt->stream_index]->time_base,
-                                     dst->streams[dst_stream]->time_base);
-    if (pkt->dts != AV_NOPTS_VALUE)
-        local_pkt.dts = av_rescale_q(pkt->dts,
-                                     src->streams[pkt->stream_index]->time_base,
-                                     dst->streams[dst_stream]->time_base);
-    if (pkt->duration)
-        local_pkt.duration = av_rescale_q(pkt->duration,
-                                          src->streams[pkt->stream_index]->time_base,
-                                          dst->streams[dst_stream]->time_base);
+
+    av_packet_rescale_ts(&local_pkt,
+                         src->streams[pkt->stream_index]->time_base,
+                         dst->streams[dst_stream]->time_base);
 
     if (interleave) ret = av_interleaved_write_frame(dst, &local_pkt);
     else            ret = av_write_frame(dst, &local_pkt);