--- ffmpeg/libavcodec/dxva2_vc1.c	2017-12-19 14:46:36.070857200 +0100
+++ ffmpeg/libavcodec/dxva2_vc1.c.refcrash	2017-12-19 14:36:57.157973200 +0100
@@ -58,11 +58,11 @@ static void fill_picture_parameters(AVCo
     memset(pp, 0, sizeof(*pp));
     pp->wDecodedPictureIndex    =
     pp->wDeblockedPictureIndex  = ff_dxva2_get_surface_index(avctx, ctx, current_picture->f);
-    if (s->pict_type != AV_PICTURE_TYPE_I && !v->bi_type)
+    if (s->pict_type != AV_PICTURE_TYPE_I && !v->bi_type && s->last_picture.f->buf[0])
         pp->wForwardRefPictureIndex = ff_dxva2_get_surface_index(avctx, ctx, s->last_picture.f);
     else
         pp->wForwardRefPictureIndex = 0xffff;
-    if (s->pict_type == AV_PICTURE_TYPE_B && !v->bi_type)
+    if (s->pict_type == AV_PICTURE_TYPE_B && !v->bi_type && s->next_picture.f->buf[0])
         pp->wBackwardRefPictureIndex = ff_dxva2_get_surface_index(avctx, ctx, s->next_picture.f);
     else
         pp->wBackwardRefPictureIndex = 0xffff;
--- ffmpeg/libavcodec/dxva2_mpeg2.c	2018-01-23 12:58:14.672161600 +0100
+++ ffmpeg/libavcodec/dxva2_mpeg2.c.ref	2018-01-23 12:56:45.439743300 +0100
@@ -51,11 +51,11 @@ static void fill_picture_parameters(AVCo
     memset(pp, 0, sizeof(*pp));
     pp->wDecodedPictureIndex         = ff_dxva2_get_surface_index(avctx, ctx, current_picture->f);
     pp->wDeblockedPictureIndex       = 0;
-    if (s->pict_type != AV_PICTURE_TYPE_I)
+    if (s->pict_type != AV_PICTURE_TYPE_I && s->last_picture.f->buf[0])
         pp->wForwardRefPictureIndex  = ff_dxva2_get_surface_index(avctx, ctx, s->last_picture.f);
     else
         pp->wForwardRefPictureIndex  = 0xffff;
-    if (s->pict_type == AV_PICTURE_TYPE_B)
+    if (s->pict_type == AV_PICTURE_TYPE_B && s->next_picture.f->buf[0])
         pp->wBackwardRefPictureIndex = ff_dxva2_get_surface_index(avctx, ctx, s->next_picture.f);
     else
         pp->wBackwardRefPictureIndex = 0xffff;