Refactor tx_size use case in the RD loop

Use table access to replace the enum arithmetic computations.

Change-Id: I573c301b16f30eb9fa147b3b3ec02af5cdad7444

av1/encoder/encodemb.c

diff --git a/av1/encoder/encodemb.c b/av1/encoder/encodemb.c
index bc1c521..1178282 100644
--- a/av1/encoder/encodemb.c
+++ b/av1/encoder/encodemb.c
@@ -928,7 +928,7 @@
   const int src_stride = p->src.stride;
   const int dst_stride = pd->dst.stride;
 
-  int tx1d_size = get_tx1d_size(tx_size);
+  int tx1d_size = tx_size_1d[tx_size];
 
   FWD_TXFM_PARAM fwd_txfm_param;
   fwd_txfm_param.tx_type = tx_type;

av1/encoder/hybrid_fwd_txfm.h

diff --git a/av1/encoder/hybrid_fwd_txfm.h b/av1/encoder/hybrid_fwd_txfm.h
index 5afd05f..9cd8c11 100644
--- a/av1/encoder/hybrid_fwd_txfm.h
+++ b/av1/encoder/hybrid_fwd_txfm.h
@@ -60,16 +60,6 @@
 }
 #endif  // CONFIG_AOM_HIGHBITDEPTH
 
-static INLINE int get_tx1d_size(TX_SIZE tx_size) {
-  switch (tx_size) {
-    case TX_32X32: return 32;
-    case TX_16X16: return 16;
-    case TX_8X8: return 8;
-    case TX_4X4: return 4;
-    default: assert(0); return -1;
-  }
-}
-
 #ifdef __cplusplus
 }  // extern "C"
 #endif

av1/encoder/rdopt.c

diff --git a/av1/encoder/rdopt.c b/av1/encoder/rdopt.c
index 2f2b598..e7cb214 100644
--- a/av1/encoder/rdopt.c
+++ b/av1/encoder/rdopt.c
@@ -471,7 +471,7 @@
 
 static void dist_block(MACROBLOCK *x, int plane, int block, TX_SIZE tx_size,
                        int64_t *out_dist, int64_t *out_sse) {
-  const int ss_txfrm_size = tx_size << 1;
+  const int ss_txfrm_size = 1 << (tx_size_1d_log2[tx_size] << 1);
   MACROBLOCKD *const xd = &x->e_mbd;
   const struct macroblock_plane *const p = &x->plane[plane];
   const struct macroblockd_plane *const pd = &xd->plane[plane];
@@ -481,12 +481,12 @@
   tran_low_t *const dqcoeff = BLOCK_OFFSET(pd->dqcoeff, block);
 #if CONFIG_AOM_HIGHBITDEPTH
   const int bd = (xd->cur_buf->flags & YV12_FLAG_HIGHBITDEPTH) ? xd->bd : 8;
-  *out_dist = av1_highbd_block_error(coeff, dqcoeff, 16 << ss_txfrm_size,
-                                     &this_sse, bd) >>
-              shift;
+  *out_dist =
+      av1_highbd_block_error(coeff, dqcoeff, ss_txfrm_size, &this_sse, bd) >>
+      shift;
 #else
   *out_dist =
-      av1_block_error(coeff, dqcoeff, 16 << ss_txfrm_size, &this_sse) >> shift;
+      av1_block_error(coeff, dqcoeff, ss_txfrm_size, &this_sse) >> shift;
 #endif  // CONFIG_AOM_HIGHBITDEPTH
   *out_sse = this_sse >> shift;
 }
@@ -517,19 +517,23 @@
                            &b_args);
     dist_block(x, plane, block, tx_size, &dist, &sse);
   } else if (max_txsize_lookup[plane_bsize] == tx_size) {
-    if (x->skip_txfm[(plane << 2) + (block >> (tx_size << 1))] ==
+    if (x->skip_txfm[(plane << 2) +
+                     (block >> (tx_size_1d_in_unit_log2[tx_size] * 2))] ==
         SKIP_TXFM_NONE) {
       // full forward transform and quantization
       av1_xform_quant(x, plane, block, blk_row, blk_col, plane_bsize, tx_size);
       dist_block(x, plane, block, tx_size, &dist, &sse);
-    } else if (x->skip_txfm[(plane << 2) + (block >> (tx_size << 1))] ==
-               SKIP_TXFM_AC_ONLY) {
+    } else if (x->skip_txfm[(plane << 2) +
+                            (block >> (tx_size_1d_in_unit_log2[tx_size] *
+                                       2))] == SKIP_TXFM_AC_ONLY) {
       // compute DC coefficient
       tran_low_t *const coeff = BLOCK_OFFSET(x->plane[plane].coeff, block);
       tran_low_t *const dqcoeff = BLOCK_OFFSET(xd->plane[plane].dqcoeff, block);
       av1_xform_quant_dc(x, plane, block, blk_row, blk_col, plane_bsize,
                          tx_size);
-      sse = x->bsse[(plane << 2) + (block >> (tx_size << 1))] << 4;
+      sse = x->bsse[(plane << 2) +
+                    (block >> (tx_size_1d_in_unit_log2[tx_size] * 2))]
+            << 4;
       dist = sse;
       if (x->plane[plane].eobs[block]) {
         const int64_t orig_sse = (int64_t)coeff[0] * coeff[0];
@@ -546,7 +550,9 @@
       // SKIP_TXFM_AC_DC
       // skip forward transform
       x->plane[plane].eobs[block] = 0;
-      sse = x->bsse[(plane << 2) + (block >> (tx_size << 1))] << 4;
+      sse = x->bsse[(plane << 2) +
+                    (block >> (tx_size_1d_in_unit_log2[tx_size] * 2))]
+            << 4;
       dist = sse;
     }
   } else {