@@ -270,15 +270,16 @@ static void gxf_track_tags(AVIOContext *pb, int *len, struct gxf_stream_info *si

  */

 static void gxf_read_index(AVFormatContext *s, int pkt_len) {

     AVIOContext *pb = s->pb;

-    AVStream *st = s->streams[0];

+    AVStream *st;

     uint32_t fields_per_map = avio_rl32(pb);

     uint32_t map_cnt = avio_rl32(pb);

     int i;

     pkt_len -= 8;

-    if (s->flags & AVFMT_FLAG_IGNIDX) {

+    if ((s->flags & AVFMT_FLAG_IGNIDX) || !s->streams) {

         avio_skip(pb, pkt_len);

         return;

     }

+    st = s->streams[0];

     if (map_cnt > 1000) {

         av_log(s, AV_LOG_ERROR, "too many index entries %u (%x)\n", map_cnt, map_cnt);

         map_cnt = 1000;