Fix select filter level

Only use cm->mi, instead of cm->mi_grid_visible to get filter level.
The latter may not work for shifted grid loop filtering.

Change-Id: I55ed6a42f0abb19d6814e8c0cf8d64ce79bf6abc

av1/common/av1_loopfilter.c

diff --git a/av1/common/av1_loopfilter.c b/av1/common/av1_loopfilter.c
index ae4d435..b5012ff 100644
--- a/av1/common/av1_loopfilter.c
+++ b/av1/common/av1_loopfilter.c
@@ -597,9 +597,12 @@
 #if CONFIG_LOOPFILTER_LEVEL
                                 const int dir_idx,
 #endif
+#if CONFIG_LPF_SB
+                                int mi_row, int mi_col,
+#endif
                                 const MB_MODE_INFO *mbmi) {
 #if CONFIG_LPF_SB
-  return mbmi->filt_lvl;
+  return cm->mi[mi_row * cm->mi_stride + mi_col].mbmi.filt_lvl;
 #endif
 
 #if CONFIG_SUPERTX
@@ -647,10 +650,6 @@
 #else
 static uint8_t get_filter_level(const loop_filter_info_n *lfi_n,
                                 const MB_MODE_INFO *mbmi) {
-#if CONFIG_LPF_SB
-  return mbmi->filt_lvl;
-#endif
-
 #if CONFIG_SUPERTX
   const int segment_id = AOMMIN(mbmi->segment_id, mbmi->segment_id_supertx);
   assert(
@@ -1461,7 +1460,11 @@
 #if CONFIG_LOOPFILTER_LEVEL
   const int filter_level = get_filter_level(cm, lfi_n, 0, mbmi);
 #else
+#if CONFIG_LPF_SB
+  const int filter_level = get_filter_level(cm, lfi_n, 0, 0, mbmi);
+#else
   const int filter_level = get_filter_level(cm, lfi_n, mbmi);
+#endif  // CONFIG_LPF_SB
 #endif
 #else
   const int filter_level = get_filter_level(lfi_n, mbmi);
@@ -1559,7 +1562,11 @@
 #if CONFIG_LOOPFILTER_LEVEL
   const int filter_level = get_filter_level(cm, lfi_n, 0, mbmi);
 #else
+#if CONFIG_LPF_SB
+  const int filter_level = get_filter_level(cm, lfi_n, 0, 0, mbmi);
+#else
   const int filter_level = get_filter_level(cm, lfi_n, mbmi);
+#endif  // CONFIG_LPF_SB
 #endif
 #else
   const int filter_level = get_filter_level(lfi_n, mbmi);
@@ -2169,7 +2176,13 @@
     if (!(lfl_r[c_step] = get_filter_level(cm, &cm->lf_info, 0, mbmi)))
       continue;
 #else
+#if CONFIG_LPF_SB
+    if (!(lfl_r[c_step] =
+              get_filter_level(cm, &cm->lf_info, mi_row, mi_col, mbmi)))
+      continue;
+#else
     if (!(lfl_r[c_step] = get_filter_level(cm, &cm->lf_info, mbmi))) continue;
+#endif  // CONFIG_LPF_SB
 #endif
 #else
     if (!(lfl_r[c_step] = get_filter_level(&cm->lf_info, mbmi))) continue;
@@ -2867,7 +2880,12 @@
     const uint32_t curr_level =
         get_filter_level(cm, &cm->lf_info, edge_dir, mbmi);
 #else
+#if CONFIG_LPF_SB
+    const uint32_t curr_level =
+        get_filter_level(cm, &cm->lf_info, mi_row, mi_col, mbmi);
+#else
     const uint32_t curr_level = get_filter_level(cm, &cm->lf_info, mbmi);
+#endif  // CONFIG_LPF_SB
 #endif
 #else
     const uint32_t curr_level = get_filter_level(&cm->lf_info, mbmi);
@@ -2904,8 +2922,13 @@
           const uint32_t pv_lvl =
               get_filter_level(cm, &cm->lf_info, edge_dir, &mi_prev->mbmi);
 #else
+#if CONFIG_LPF_SB
+          const uint32_t pv_lvl = get_filter_level(cm, &cm->lf_info, pv_row,
+                                                   pv_col, &mi_prev->mbmi);
+#else
           const uint32_t pv_lvl =
               get_filter_level(cm, &cm->lf_info, &mi_prev->mbmi);
+#endif  // CONFIG_LPF_SB
 #endif
 #else
           const uint32_t pv_lvl =

av1/encoder/picklpf.c

diff --git a/av1/encoder/picklpf.c b/av1/encoder/picklpf.c
index 2869860..d8b6f90 100644
--- a/av1/encoder/picklpf.c
+++ b/av1/encoder/picklpf.c
@@ -232,6 +232,10 @@
     filt_best = last_lvl;
   }
 
+  // Compute rdcost to determine whether to reuse previous filter lvl
+  if (filt_best != last_lvl) {
+  }
+
   if (best_cost_ret) *best_cost_ret = RDCOST_DBL(x->rdmult, 0, best_err);
   return filt_best;
 }