Properly update the lv-map context in the RD loop

Account for the txb_optimize effect on level map context modeling
in the transform block rate distortion optimization search.
Properly update such information in the txb hash rd cost.

BUG=aomedia:1118

Change-Id: I16cf80c57fa37929f94291a7500d84f9e0778400

av1/encoder/block.h

@@ -147,6 +147,7 @@ typedef struct {
   uint16_t eob;
 #if CONFIG_LV_MAP
   uint16_t entropy_context;
+  uint8_t txb_entropy_ctx;
 #else
   uint8_t entropy_context;
 #endif

av1/encoder/encodetxb.c

@@ -2042,9 +2042,14 @@ int av1_optimize_txb(const AV1_COMMON *cm, MACROBLOCK *x, int plane,
 
   const int update = optimize_txb(&txb_info, &txb_costs, NULL, 0, fast_mode);
 
-  if (update) p->eobs[block] = txb_info.eob;
+  if (update) {
+    p->eobs[block] = txb_info.eob;
+    p->txb_entropy_ctx[block] =
+        av1_get_txb_entropy_context(qcoeff, scan_order, txb_info.eob);
+  }
   return txb_info.eob;
 }
+
 int av1_get_txb_entropy_context(const tran_low_t *qcoeff,
                                 const SCAN_ORDER *scan_order, int eob) {
   const int16_t *const scan = scan_order->scan;

av1/encoder/rdopt.c

@@ -3700,6 +3700,9 @@ void av1_tx_block_rd_b(const AV1_COMP *cpi, MACROBLOCK *x, TX_SIZE tx_size,
     rd_stats->rate += rd_info_array[tx_type].rate;
     rd_stats->skip &= rd_info_array[tx_type].eob == 0;
     p->eobs[block] = rd_info_array[tx_type].eob;
+#if CONFIG_LV_MAP
+    p->txb_entropy_ctx[block] = rd_info_array[tx_type].txb_entropy_ctx;
+#endif
     return;
   }
 
@@ -3830,6 +3833,9 @@ void av1_tx_block_rd_b(const AV1_COMP *cpi, MACROBLOCK *x, TX_SIZE tx_size,
     rd_info_array[tx_type].dist = cur_dist;
     rd_info_array[tx_type].rate = cur_rate;
     rd_info_array[tx_type].eob = eob;
+#if CONFIG_LV_MAP
+    rd_info_array[tx_type].txb_entropy_ctx = p->txb_entropy_ctx[block];
+#endif
   }
 
   rd_stats->dist += cur_dist;