diff --git a/libavcodec/h264.c b/libavcodec/h264.c
index 94ab6163de..33aeaedf6b 100644
--- a/libavcodec/h264.c
+++ b/libavcodec/h264.c
@@ -3212,6 +3212,7 @@ static int decode_slice_header(H264Context *h, H264Context *h0)
     int last_pic_structure, last_pic_droppable;
     int must_reinit;
     int needs_reinit = 0;
+    int field_pic_flag, bottom_field_flag;
 
     h->me.qpel_put = h->h264qpel.put_h264_qpel_pixels_tab;
     h->me.qpel_avg = h->h264qpel.avg_h264_qpel_pixels_tab;
@@ -3404,8 +3405,10 @@ static int decode_slice_header(H264Context *h, H264Context *h0)
             av_log(h->avctx, AV_LOG_ERROR, "This stream was generated by a broken encoder, invalid 8x8 inference\n");
             return -1;
         }
-        if (get_bits1(&h->gb)) { // field_pic_flag
-            h->picture_structure = PICT_TOP_FIELD + get_bits1(&h->gb); // bottom_field_flag
+        field_pic_flag = get_bits1(&h->gb);
+        if (field_pic_flag) {
+            bottom_field_flag = get_bits1(&h->gb);
+            h->picture_structure = PICT_TOP_FIELD + bottom_field_flag;
         } else {
             h->picture_structure = PICT_FRAME;
             h->mb_aff_frame      = h->sps.mb_aff;