rtpdec: factorize identical code used in several handlers

libavformat/rtpdec_xiph.c

@@ -202,20 +202,13 @@ static int xiph_handle_packet(AVFormatContext * ctx,
 
         if (fragmented == 3) {
             // end of xiph data packet
-            av_init_packet(pkt);
-            pkt->size = avio_close_dyn_buf(data->fragment, &pkt->data);
-
-            if (pkt->size < 0) {
+            int ret = ff_rtp_finalize_packet(pkt, &data->fragment, st->index);
+            if (ret < 0) {
                 av_log(ctx, AV_LOG_ERROR,
                        "Error occurred when getting fragment buffer.");
-                return pkt->size;
+                return ret;
             }
 
-            pkt->stream_index = st->index;
-            pkt->destruct = av_destruct_packet;
-
-            data->fragment = NULL;
-
             return 0;
         }
     }