mpegts: factor seek_back() out

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

libavformat/mpegts.c

@@ -1986,6 +1986,15 @@ static int parse_pcr(int64_t *ppcr_high, int *ppcr_low,
     return 0;
 }
 
+static void seek_back(AVFormatContext *s, AVIOContext *pb, int64_t pos) {
+
+    /* NOTE: We attempt to seek on non-seekable files as well, as the
+     * probe buffer usually is big enough. Only warn if the seek failed
+     * on files where the seek should work. */
+    if (avio_seek(pb, pos, SEEK_SET) < 0)
+        av_log(s, pb->seekable ? AV_LOG_ERROR : AV_LOG_INFO, "Unable to seek back to the start\n");
+}
+
 static int mpegts_read_header(AVFormatContext *s)
 {
     MpegTSContext *ts = s->priv_data;
@@ -2009,11 +2018,7 @@ static int mpegts_read_header(AVFormatContext *s)
         /* normal demux */
 
         /* first do a scan to get all the services */
-        /* NOTE: We attempt to seek on non-seekable files as well, as the
-         * probe buffer usually is big enough. Only warn if the seek failed
-         * on files where the seek should work. */
-        if (avio_seek(pb, pos, SEEK_SET) < 0)
-            av_log(s, pb->seekable ? AV_LOG_ERROR : AV_LOG_INFO, "Unable to seek back to the start\n");
+        seek_back(s, pb, pos);
 
         mpegts_open_section_filter(ts, SDT_PID, sdt_cb, ts, 1);