diff --git a/av1/common/entropymode.h b/av1/common/entropymode.h
index d0ad807ea5f8491c9ba16eb76ca9e6fb514a2b88..85c68e17a83d07baa7d81d9d7acec86d883707e4 100644
--- a/av1/common/entropymode.h
+++ b/av1/common/entropymode.h
@@ -41,6 +41,12 @@ extern "C" {
 
 struct AV1Common;
 
+typedef struct {
+  const int16_t *scan;
+  const int16_t *iscan;
+  const int16_t *neighbors;
+} SCAN_ORDER;
+
 struct seg_counts {
   unsigned int tree_total[MAX_SEGMENTS];
   unsigned int tree_mispred[MAX_SEGMENTS];
@@ -62,6 +68,31 @@ typedef struct frame_contexts {
   aom_prob switchable_interp_prob[SWITCHABLE_FILTER_CONTEXTS]
                                  [SWITCHABLE_FILTERS - 1];
 
+#if CONFIG_ADAPT_SCAN
+  // TODO(angiebird): try aom_prob
+  uint32_t non_zero_prob_4X4[TX_TYPES][16];
+  uint32_t non_zero_prob_8X8[TX_TYPES][64];
+  uint32_t non_zero_prob_16X16[TX_TYPES][256];
+  uint32_t non_zero_prob_32X32[TX_TYPES][1024];
+
+  DECLARE_ALIGNED(16, int16_t, scan_4X4[TX_TYPES][16]);
+  DECLARE_ALIGNED(16, int16_t, scan_8X8[TX_TYPES][64]);
+  DECLARE_ALIGNED(16, int16_t, scan_16X16[TX_TYPES][256]);
+  DECLARE_ALIGNED(16, int16_t, scan_32X32[TX_TYPES][1024]);
+
+  DECLARE_ALIGNED(16, int16_t, iscan_4X4[TX_TYPES][16]);
+  DECLARE_ALIGNED(16, int16_t, iscan_8X8[TX_TYPES][64]);
+  DECLARE_ALIGNED(16, int16_t, iscan_16X16[TX_TYPES][256]);
+  DECLARE_ALIGNED(16, int16_t, iscan_32X32[TX_TYPES][1024]);
+
+  int16_t nb_4X4[TX_TYPES][(16 + 1) * 2];
+  int16_t nb_8X8[TX_TYPES][(64 + 1) * 2];
+  int16_t nb_16X16[TX_TYPES][(256 + 1) * 2];
+  int16_t nb_32X32[TX_TYPES][(1024 + 1) * 2];
+
+  SCAN_ORDER sc[TX_SIZES][TX_TYPES];
+#endif  // CONFIG_ADAPT_SCAN
+
 #if CONFIG_REF_MV
   aom_prob newmv_prob[NEWMV_MODE_CONTEXTS];
   aom_prob zeromv_prob[ZEROMV_MODE_CONTEXTS];
@@ -161,6 +192,14 @@ typedef struct FRAME_COUNTS {
                          [COEFF_CONTEXTS];
   unsigned int switchable_interp[SWITCHABLE_FILTER_CONTEXTS]
                                 [SWITCHABLE_FILTERS];
+#if CONFIG_ADAPT_SCAN
+  unsigned int non_zero_count_4X4[TX_TYPES][16];
+  unsigned int non_zero_count_8X8[TX_TYPES][64];
+  unsigned int non_zero_count_16X16[TX_TYPES][256];
+  unsigned int non_zero_count_32X32[TX_TYPES][1024];
+  unsigned int txb_count[TX_SIZES][TX_TYPES];
+#endif
+
 #if CONFIG_REF_MV
   unsigned int newmv_mode[NEWMV_MODE_CONTEXTS][2];
   unsigned int zeromv_mode[ZEROMV_MODE_CONTEXTS][2];
diff --git a/av1/common/scan.h b/av1/common/scan.h
index c183ba980bb891f7b07b20b50d8db70ecb3b7e05..35b7de146c08f542e4fe88f5a3c99c94107b426e 100644
--- a/av1/common/scan.h
+++ b/av1/common/scan.h
@@ -24,12 +24,6 @@ extern "C" {
 
 #define MAX_NEIGHBORS 2
 
-typedef struct {
-  const int16_t *scan;
-  const int16_t *iscan;
-  const int16_t *neighbors;
-} SCAN_ORDER;
-
 extern const SCAN_ORDER av1_default_scan_orders[TX_SIZES];
 extern const SCAN_ORDER av1_intra_scan_orders[TX_SIZES][TX_TYPES];
 
diff --git a/configure b/configure
index 7901ef39673ec1360f5def97833e6982ea18899c..99d2bb837beaadd46ce9c21a3de409c607b23834 100755
--- a/configure
+++ b/configure
@@ -287,6 +287,7 @@ EXPERIMENT_LIST="
     cb4x4
     frame_size
     delta_q
+    adapt_scan
 "
 CONFIG_LIST="
     dependency_tracking