diff --git a/libavcodec/dirac_parser.c b/libavcodec/dirac_parser.c
index c7c4b697c8..1ca7e31f1c 100644
--- a/libavcodec/dirac_parser.c
+++ b/libavcodec/dirac_parser.c
@@ -201,7 +201,7 @@ static int dirac_combine_frame(AVCodecParserContext *s, AVCodecContext *avctx,
         }
 
         /* Get the picture number to set the pts and dts*/
-        if (parse_timing_info) {
+        if (parse_timing_info && pu1.prev_pu_offset >= 13) {
             uint8_t *cur_pu = pc->buffer +
                               pc->index - 13 - pu1.prev_pu_offset;
             int pts = AV_RB32(cur_pu + 13);