@@ -849,16 +849,17 @@ FF_ENABLE_DEPRECATION_WARNINGS

     if (s->version > 1) {

         int plane_count = 1 + 2*s->chroma_planes + s->transparency;

+        int max_h_slices = AV_CEIL_RSHIFT(avctx->width , s->chroma_h_shift);

+        int max_v_slices = AV_CEIL_RSHIFT(avctx->height, s->chroma_v_shift);

         s->num_v_slices = (avctx->width > 352 || avctx->height > 288 || !avctx->slices) ? 2 : 1;

-        if (avctx->height < 5)

-            s->num_v_slices = 1;

+        s->num_v_slices = FFMIN(s->num_v_slices, max_v_slices);

         for (; s->num_v_slices < 32; s->num_v_slices++) {

             for (s->num_h_slices = s->num_v_slices; s->num_h_slices < 2*s->num_v_slices; s->num_h_slices++) {

                 int maxw = (avctx->width  + s->num_h_slices - 1) / s->num_h_slices;

                 int maxh = (avctx->height + s->num_v_slices - 1) / s->num_v_slices;

-                if (s->num_h_slices > avctx->width || s->num_v_slices > avctx->height)

+                if (s->num_h_slices > max_h_slices || s->num_v_slices > max_v_slices)

                     continue;

                 if (maxw * maxh * (int64_t)(s->bits_per_raw_sample+1) * plane_count > 8<<24)

                     continue;