Assert no mv clamping for scaled references

Under --enable-better-hw-compabibility, this commit adds the asserts
that no mv clamping is applied for scaled references, so when built
with this configure option, decoder will assert if an input bitstream
triggger mv clamping for scaled reference frames.

Change-Id: I786e86a2bbbfb5bc2d2b706a31b0ffa8fe2eb0cb

2 files changed, 11 insertions, 4 deletions

diff --git a/vp9/common/vp9_reconinter.c b/vp9/common/vp9_reconinter.c
index 3eb19b124..37658dc94 100644
--- a/vp9/common/vp9_reconinter.c
+++ b/vp9/common/vp9_reconinter.c
@@ -187,13 +187,15 @@ static void build_inter_predictors(MACROBLOCKD *xd, int plane, int block,
     const int is_scaled = vp9_is_scaled(sf);
 
     if (is_scaled) {
+      // Co-ordinate of containing block to pixel precision.
+      const int x_start = (-xd->mb_to_left_edge >> (3 + pd->subsampling_x));
+      const int y_start = (-xd->mb_to_top_edge >> (3 + pd->subsampling_y));
 #if CONFIG_BETTER_HW_COMPATIBILITY
       assert(xd->mi[0]->mbmi.sb_type != BLOCK_4X8 &&
              xd->mi[0]->mbmi.sb_type != BLOCK_8X4);
+      assert(mv_q4.row == mv.row * (1 << (1 - pd->subsampling_y)) &&
+             mv_q4.col == mv.col * (1 << (1 - pd->subsampling_x)));
 #endif
-      // Co-ordinate of containing block to pixel precision.
-      const int x_start = (-xd->mb_to_left_edge >> (3 + pd->subsampling_x));
-      const int y_start = (-xd->mb_to_top_edge >> (3 + pd->subsampling_y));
       if (plane == 0)
         pre_buf->buf = xd->block_refs[ref]->buf->y_buffer;
       else if (plane == 1)
diff --git a/vp9/decoder/vp9_decodeframe.c b/vp9/decoder/vp9_decodeframe.c
index 39e4dcfe3..3fd87cc3a 100644
--- a/vp9/decoder/vp9_decodeframe.c
+++ b/vp9/decoder/vp9_decodeframe.c
@@ -587,7 +587,12 @@ static void dec_build_inter_predictors(VP9Decoder *const pbi, MACROBLOCKD *xd,
     // Co-ordinate of containing block to pixel precision.
     int x_start = (-xd->mb_to_left_edge >> (3 + pd->subsampling_x));
     int y_start = (-xd->mb_to_top_edge >> (3 + pd->subsampling_y));
-
+#if CONFIG_BETTER_HW_COMPATIBILITY
+    assert(xd->mi[0]->mbmi.sb_type != BLOCK_4X8 &&
+           xd->mi[0]->mbmi.sb_type != BLOCK_8X4);
+    assert(mv_q4.row == mv->row * (1 << (1 - pd->subsampling_y)) &&
+           mv_q4.col == mv->col * (1 << (1 - pd->subsampling_x)));
+#endif
     // Co-ordinate of the block to 1/16th pixel precision.
     x0_16 = (x_start + x) << SUBPEL_BITS;
     y0_16 = (y_start + y) << SUBPEL_BITS;