@@ -370,8 +370,19 @@ static int rm_read_index(AVFormatContext *s)

                 st = s->streams[n];

                 break;

             }

-        if (n == s->nb_streams)

+        if (n == s->nb_streams) {

+            av_log(s, AV_LOG_ERROR,

+                   "Invalid stream index %d for index at pos %"PRId64"\n",

+                   str_id, avio_tell(pb));

             goto skip;

+        } else if ((avio_size(pb) - avio_tell(pb)) / 14 < n_pkts) {

+            av_log(s, AV_LOG_ERROR,

+                   "Nr. of packets in packet index for stream index %d "

+                   "exceeds filesize (%"PRId64" at %"PRId64" = %d)\n",

+                   str_id, avio_size(pb), avio_tell(pb),

+                   (avio_size(pb) - avio_tell(pb)) / 14);

+            goto skip;

+        }

         for (n = 0; n < n_pkts; n++) {

             avio_skip(pb, 2);

@@ -383,9 +394,12 @@ static int rm_read_index(AVFormatContext *s)

         }

 skip:

-        if (next_off && avio_tell(pb) != next_off &&

-            avio_seek(pb, next_off, SEEK_SET) < 0)

+        if (next_off && avio_tell(pb) < next_off &&

+            avio_seek(pb, next_off, SEEK_SET) < 0) {

+            av_log(s, AV_LOG_ERROR,

+                   "Non-linear index detected, not supported\n");

             return -1;

+        }

     } while (next_off);

     return 0;