Add transform coefficient decode function

Change-Id: I222b5ce9ee1a1c1aac5620b94835967dd9a014c1

av1/av1_dx.mk

@@ -23,6 +23,8 @@ AV1_DX_SRCS-yes += decoder/decodeframe.c
 AV1_DX_SRCS-yes += decoder/decodeframe.h
 AV1_DX_SRCS-yes += decoder/detokenize.c
 AV1_DX_SRCS-yes += decoder/decodemv.h
+AV1_DX_SRCS-$(CONFIG_LV_MAP) += decoder/decodetxb.c
+AV1_DX_SRCS-$(CONFIG_LV_MAP) += decoder/decodetxb.h
 AV1_DX_SRCS-yes += decoder/detokenize.h
 AV1_DX_SRCS-yes += decoder/dthread.c
 AV1_DX_SRCS-yes += decoder/dthread.h

av1/common/txb_common.h

@@ -95,6 +95,11 @@ static int16_t coeff_band_32x32[1024] = {
   22, 23, 23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24,
 };
 
+typedef struct txb_ctx {
+  int txb_skip_ctx;
+  int dc_sign_ctx;
+} TXB_CTX;
+
 #define BASE_CONTEXT_POSITION_NUM 12
 static int base_ref_offset[BASE_CONTEXT_POSITION_NUM][2] = {
   /* clang-format off*/
@@ -296,4 +301,10 @@ static INLINE int get_eob_ctx(const tran_low_t *tcoeffs,
   exit(0);
 }
 
+static INLINE void set_dc_sign(int *cul_level, tran_low_t v) {
+  if (v < 0)
+    *cul_level |= 1 << COEFF_CONTEXT_BITS;
+  else if (v > 0)
+    *cul_level += 2 << COEFF_CONTEXT_BITS;
+}
 #endif  // AV1_COMMON_TXB_COMMON_H_

av1/decoder/decodetxb.c

@@ -0,0 +1,184 @@
+/*
+ * Copyright (c) 2017, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+
+#include "av1/common/scan.h"
+#include "av1/common/txb_common.h"
+#include "av1/decoder/decodetxb.h"
+
+#define ACCT_STR __func__
+
+static int read_golomb(aom_reader *r) {
+  int x = 1;
+  int length = 0;
+  int i = 0;
+
+  while (!i) {
+    i = aom_read_bit(r, ACCT_STR);
+    ++length;
+  }
+
+  for (i = 0; i < length - 1; ++i) {
+    x <<= 1;
+    x += aom_read_bit(r, ACCT_STR);
+  }
+
+  return x - 1;
+}
+
+uint8_t av1_read_coeffs_txb(const AV1_COMMON *const cm, MACROBLOCKD *xd,
+                            aom_reader *r, int block, int plane,
+                            tran_low_t *tcoeffs, TXB_CTX *txb_ctx) {
+  FRAME_COUNTS *counts = xd->counts;
+  TX_SIZE tx_size = get_tx_size(plane, xd, block);
+  PLANE_TYPE plane_type = get_plane_type(plane);
+  aom_prob *nz_map = cm->fc->nz_map[tx_size][plane_type];
+  aom_prob *eob_flag = cm->fc->eob_flag[tx_size][plane_type];
+  MB_MODE_INFO *mbmi = &xd->mi[0]->mbmi;
+  const TX_TYPE tx_type = get_tx_type(plane_type, xd, block, tx_size);
+  const SCAN_ORDER *const scan_order =
+      get_scan(cm, tx_size, tx_type, is_inter_block(mbmi));
+  const int16_t *scan = scan_order->scan;
+  const int seg_eob = 16 << (tx_size << 1);
+  int c = 0;
+  int eob = 0, update_eob = -1;
+  const int16_t *const dequant = xd->plane[plane].seg_dequant[mbmi->segment_id];
+  const int shift = (tx_size == TX_32X32);
+  const int bwl = b_width_log2_lookup[txsize_to_bsize[tx_size]] + 2;
+  int cul_level = 0;
+  unsigned int(*nz_map_count)[SIG_COEF_CONTEXTS][2];
+  uint8_t txb_mask[32 * 32] = { 0 };
+
+  nz_map_count = (counts) ? &counts->nz_map[tx_size][plane_type] : NULL;
+
+  memset(tcoeffs, 0, sizeof(*tcoeffs) * seg_eob);
+
+  for (c = 0; c < seg_eob; ++c) {
+    int is_nz;
+    int coeff_ctx = get_nz_map_ctx(tcoeffs, txb_mask, scan[c], bwl);
+    int eob_ctx = get_eob_ctx(tcoeffs, scan[c], bwl);
+
+    if (c < seg_eob - 1)
+      is_nz = aom_read(r, nz_map[coeff_ctx], tx_size);
+    else
+      is_nz = 1;
+
+    // set non-zero coefficient map.
+    tcoeffs[scan[c]] = is_nz;
+
+    if (c == seg_eob - 1) {
+      ++c;
+      break;
+    }
+
+    if (counts) ++(*nz_map_count)[coeff_ctx][is_nz];
+
+    if (is_nz) {
+      int is_eob = aom_read(r, eob_flag[eob_ctx], tx_size);
+      if (counts) ++counts->eob_flag[tx_size][plane_type][eob_ctx][is_eob];
+      if (is_eob) break;
+    }
+    txb_mask[scan[c]] = 1;
+  }
+
+  eob = AOMMIN(seg_eob, c + 1);
+
+  int i;
+  for (i = 0; i < NUM_BASE_LEVELS; ++i) {
+    aom_prob *coeff_base = cm->fc->coeff_base[tx_size][plane_type][i];
+
+    update_eob = 0;
+    for (c = eob - 1; c >= 0; --c) {
+      tran_low_t *v = &tcoeffs[scan[c]];
+      int sign;
+      int ctx;
+
+      if (*v <= i) continue;
+
+      ctx = get_base_ctx(tcoeffs, scan[c], bwl, i + 1);
+
+      if (aom_read(r, coeff_base[ctx], tx_size)) {
+        *v = i + 1;
+        cul_level += i + 1;
+
+        if (counts) ++counts->coeff_base[tx_size][plane_type][i][ctx][1];
+
+        if (c == 0) {
+          int dc_sign_ctx = txb_ctx->dc_sign_ctx;
+          sign = aom_read(r, cm->fc->dc_sign[plane_type][dc_sign_ctx], tx_size);
+          if (counts) ++counts->dc_sign[plane_type][dc_sign_ctx][sign];
+        } else {
+          sign = aom_read_bit(r, ACCT_STR);
+        }
+        if (sign) *v = -(*v);
+        continue;
+      }
+      *v = i + 2;
+      if (counts) ++counts->coeff_base[tx_size][plane_type][i][ctx][0];
+
+      // update the eob flag for coefficients with magnitude above 1.
+      update_eob = AOMMAX(update_eob, c);
+    }
+  }
+
+  for (c = update_eob; c >= 0; --c) {
+    tran_low_t *v = &tcoeffs[scan[c]];
+    int sign;
+    int idx;
+    int ctx;
+
+    if (*v <= NUM_BASE_LEVELS) continue;
+
+    if (c == 0) {
+      int dc_sign_ctx = txb_ctx->dc_sign_ctx;
+      sign = aom_read(r, cm->fc->dc_sign[plane_type][dc_sign_ctx], tx_size);
+      if (counts) ++counts->dc_sign[plane_type][dc_sign_ctx][sign];
+    } else {
+      sign = aom_read_bit(r, ACCT_STR);
+    }
+
+    ctx = get_level_ctx(tcoeffs, scan[c], bwl);
+
+    if (cm->fc->coeff_lps[tx_size][plane_type][ctx] == 0) exit(0);
+
+    for (idx = 0; idx < COEFF_BASE_RANGE; ++idx) {
+      if (aom_read(r, cm->fc->coeff_lps[tx_size][plane_type][ctx], tx_size)) {
+        *v = (idx + 1 + NUM_BASE_LEVELS);
+        if (sign) *v = -(*v);
+        cul_level += abs(*v);
+
+        if (counts) ++counts->coeff_lps[tx_size][plane_type][ctx][1];
+        break;
+      }
+      if (counts) ++counts->coeff_lps[tx_size][plane_type][ctx][0];
+    }
+    if (idx < COEFF_BASE_RANGE) continue;
+
+    // decode 0-th order Golomb code
+    *v = read_golomb(r) + COEFF_BASE_RANGE + 1 + NUM_BASE_LEVELS;
+    if (sign) *v = -(*v);
+    cul_level += abs(*v);
+  }
+
+  for (c = 0; c < eob; ++c) {
+    int16_t dqv = (c == 0) ? dequant[0] : dequant[1];
+    tran_low_t *v = &tcoeffs[scan[c]];
+    int sign = (*v) < 0;
+    *v = (abs(*v) * dqv) >> shift;
+    if (sign) *v = -(*v);
+  }
+
+  cul_level = AOMMIN(63, cul_level);
+
+  // DC value
+  set_dc_sign(&cul_level, tcoeffs[0]);
+
+  return cul_level;
+}

av1/decoder/decodetxb.h

@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2017, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+
+#ifndef DECODETXB_H_
+#define DECODETXB_H_
+
+#include "./aom_config.h"
+#include "av1/common/blockd.h"
+#include "av1/common/onyxc_int.h"
+#include "av1/common/txb_common.h"
+#include "aom_dsp/bitreader.h"
+
+uint8_t av1_read_coeffs_txb(const AV1_COMMON *const cm, MACROBLOCKD *xd,
+                            aom_reader *r, int block, int plane,
+                            tran_low_t *tcoeffs, TXB_CTX *txb_ctx);
+
+#endif  //  DECODETXB_H_

av1/encoder/encodetxb.c

@@ -10,7 +10,6 @@
  */
 
 #include "av1/common/scan.h"
-#include "av1/common/txb_common.h"
 #include "av1/encoder/encodetxb.h"
 
 static void write_golomb(aom_writer *w, int level) {
@@ -36,7 +35,7 @@ void av1_write_coeffs_txb(const AV1_COMMON *const cm, MACROBLOCKD *xd,
   aom_prob *nz_map;
   aom_prob *eob_flag;
   MB_MODE_INFO *mbmi = &xd->mi[0]->mbmi;
-  const PLANE_TYPE plane_type = (plane == 0) ? PLANE_TYPE_Y : PLANE_TYPE_UV;
+  const PLANE_TYPE plane_type = get_plane_type(plane);
   const TX_SIZE tx_size = get_tx_size(plane, xd, block);
   const TX_TYPE tx_type = get_tx_type(plane_type, xd, block, tx_size);
   const SCAN_ORDER *const scan_order =

av1/encoder/encodetxb.h

@@ -15,16 +15,12 @@
 #include "./aom_config.h"
 #include "av1/common/blockd.h"
 #include "av1/common/onyxc_int.h"
+#include "av1/common/txb_common.h"
 #include "aom_dsp/bitwriter.h"
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-typedef struct txb_ctx {
-  int txb_skip_ctx;
-  int dc_sign_ctx;
-} TXB_CTX;
-
 void av1_write_coeffs_txb(const AV1_COMMON *const cm, MACROBLOCKD *xd,
                           aom_writer *w, int block, int plane,
                           const tran_low_t *tcoeff, uint16_t eob,