avformat/mp3dec: offset seek index to end of vbr headers

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

libavformat/mp3dec.c

@@ -334,6 +334,7 @@ static int mp3_read_header(AVFormatContext *s)
     AVStream *st;
     int64_t off;
     int ret;
+    int i;
 
     st = avformat_new_stream(s, NULL);
     if (!st)
@@ -363,6 +364,10 @@ static int mp3_read_header(AVFormatContext *s)
     if (ret < 0)
         return ret;
 
+    // the seek index is relative to the end of the xing vbr headers
+    for (i = 0; i < st->nb_index_entries; i++)
+        st->index_entries[i].pos += avio_tell(s->pb);
+
     /* the parameters will be extracted from the compressed bitstream */
     return 0;
 }