diff --git a/libavformat/rtpenc_chain.c b/libavformat/rtpenc_chain.c
index 38062543a2..10c4020cfe 100644
--- a/libavformat/rtpenc_chain.c
+++ b/libavformat/rtpenc_chain.c
@@ -96,9 +96,6 @@ int ff_rtp_chain_mux_open(AVFormatContext **out, AVFormatContext *s,
         return ret;
     }
 
-    /* Copy the RTP AVStream timebase back to the original AVStream */
-    st->time_base = rtpctx->streams[0]->time_base;
-
     *out = rtpctx;
     return 0;
 
diff --git a/libavformat/rtsp.c b/libavformat/rtsp.c
index b95be46f4f..06269bd0e1 100644
--- a/libavformat/rtsp.c
+++ b/libavformat/rtsp.c
@@ -734,6 +734,7 @@ int ff_rtsp_open_transport_ctx(AVFormatContext *s, RTSPStream *rtsp_st)
         rtsp_st->rtp_handle = NULL;
         if (ret < 0)
             return ret;
+        st->time_base = ((AVFormatContext*)rtsp_st->transport_priv)->streams[0]->time_base;
     } else if (rt->transport == RTSP_TRANSPORT_RAW) {
         return 0; // Don't need to open any parser here
     } else if (rt->transport == RTSP_TRANSPORT_RDT && CONFIG_RTPDEC)
diff --git a/libavformat/sapenc.c b/libavformat/sapenc.c
index 7e2bba7a28..246b7cfa14 100644
--- a/libavformat/sapenc.c
+++ b/libavformat/sapenc.c
@@ -157,6 +157,7 @@ static int sap_write_header(AVFormatContext *s)
         if (ret < 0)
             goto fail;
         s->streams[i]->priv_data = contexts[i];
+        s->streams[i]->time_base = contexts[i]->streams[0]->time_base;
         av_strlcpy(contexts[i]->filename, url, sizeof(contexts[i]->filename));
     }