aom/vp9/decoder/vp9_detokenize.c

/*
 *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */


#include "vp9/common/vp9_type_aliases.h"
#include "vp9/common/vp9_blockd.h"
#include "vp9_onyxd_int.h"
#include "vpx_mem/vpx_mem.h"
#include "vpx_ports/mem.h"
#include "vp9_detokenize.h"

#include "vp9/common/vp9_seg_common.h"

#define EOB_CONTEXT_NODE            0
#define ZERO_CONTEXT_NODE           1
#define ONE_CONTEXT_NODE            2
#define LOW_VAL_CONTEXT_NODE        3
#define TWO_CONTEXT_NODE            4
#define THREE_CONTEXT_NODE          5
#define HIGH_LOW_CONTEXT_NODE       6
#define CAT_ONE_CONTEXT_NODE        7
#define CAT_THREEFOUR_CONTEXT_NODE  8
#define CAT_THREE_CONTEXT_NODE      9
#define CAT_FIVE_CONTEXT_NODE       10

#define CAT1_MIN_VAL    5
#define CAT2_MIN_VAL    7
#define CAT3_MIN_VAL   11
#define CAT4_MIN_VAL   19
#define CAT5_MIN_VAL   35
#define CAT6_MIN_VAL   67
#define CAT1_PROB0    159
#define CAT2_PROB0    145
#define CAT2_PROB1    165

#define CAT3_PROB0 140
#define CAT3_PROB1 148
#define CAT3_PROB2 173

#define CAT4_PROB0 135
#define CAT4_PROB1 140
#define CAT4_PROB2 155
#define CAT4_PROB3 176

#define CAT5_PROB0 130
#define CAT5_PROB1 134
#define CAT5_PROB2 141
#define CAT5_PROB3 157
#define CAT5_PROB4 180

static const unsigned char cat6_prob[14] =
{ 254, 254, 252, 249, 243, 230, 196, 177, 153, 140, 133, 130, 129, 0 };

void vp9_reset_mb_tokens_context(MACROBLOCKD* const xd) {
  /* Clear entropy contexts for Y2 blocks */
  if ((xd->mode_info_context->mbmi.mode != B_PRED &&
      xd->mode_info_context->mbmi.mode != I8X8_PRED &&
      xd->mode_info_context->mbmi.mode != SPLITMV)
      || xd->mode_info_context->mbmi.txfm_size == TX_16X16
      ) {
    vpx_memset(xd->above_context, 0, sizeof(ENTROPY_CONTEXT_PLANES));
    vpx_memset(xd->left_context, 0, sizeof(ENTROPY_CONTEXT_PLANES));
  } else {
    vpx_memset(xd->above_context, 0, sizeof(ENTROPY_CONTEXT_PLANES) - 1);
    vpx_memset(xd->left_context, 0, sizeof(ENTROPY_CONTEXT_PLANES) - 1);
  }
}

DECLARE_ALIGNED(16, extern const unsigned char, vp9_norm[256]);

static int get_signed(BOOL_DECODER *br, int value_to_sign) {
  const int split = (br->range + 1) >> 1;
  const VP9_BD_VALUE bigsplit = (VP9_BD_VALUE)split << (VP9_BD_VALUE_SIZE - 8);
  int v;

  if (br->count < 0)
    vp9_bool_decoder_fill(br);

  if (br->value < bigsplit) {
    br->range = split;
    v = value_to_sign;
  } else {
    br->range = br->range - split;
    br->value = br->value - bigsplit;
    v = -value_to_sign;
  }
  br->range += br->range;
  br->value += br->value;
  --br->count;

  return v;
}

#define INCREMENT_COUNT(token)               \
  do {                                       \
    coef_counts[coef_bands[c]][pt][token]++; \
    pt = vp9_prev_token_class[token];        \
  } while (0)

#define WRITE_COEF_CONTINUE(val, token)                       \
  {                                                           \
    qcoeff_ptr[scan[c]] = (INT16) get_signed(br, val);        \
    INCREMENT_COUNT(token);                                   \
    c++;                                                      \
    continue;                                                 \
  }

#define ADJUST_COEF(prob, bits_count)  \
  do {                                 \
    if (vp9_read(br, prob))            \
      val += (UINT16)(1 << bits_count);\
  } while (0);

static int decode_coefs(VP9D_COMP *dx, const MACROBLOCKD *xd,
                        BOOL_DECODER* const br,
                        ENTROPY_CONTEXT *a, ENTROPY_CONTEXT *l,
                        PLANE_TYPE type,
                        TX_TYPE tx_type,
                        int seg_eob, INT16 *qcoeff_ptr,
                        const int *const scan, TX_SIZE txfm_size,
                        const int *coef_bands) {
  FRAME_CONTEXT *const fc = &dx->common.fc;
  int pt, c = (type == PLANE_TYPE_Y_NO_DC);
  vp9_prob (*coef_probs)[PREV_COEF_CONTEXTS][ENTROPY_NODES], *prob;
  unsigned int (*coef_counts)[PREV_COEF_CONTEXTS][MAX_ENTROPY_TOKENS];

  switch (txfm_size) {
    default:
    case TX_4X4:
      if (tx_type == DCT_DCT) {
        coef_probs  = fc->coef_probs[type];
        coef_counts = fc->coef_counts[type];
      } else {
        coef_probs  = fc->hybrid_coef_probs[type];
        coef_counts = fc->hybrid_coef_counts[type];
      }
      break;
    case TX_8X8:
      if (tx_type == DCT_DCT) {
        coef_probs  = fc->coef_probs_8x8[type];
        coef_counts = fc->coef_counts_8x8[type];
      } else {
        coef_probs  = fc->hybrid_coef_probs_8x8[type];
        coef_counts = fc->hybrid_coef_counts_8x8[type];
      }
      break;
    case TX_16X16:
      if (tx_type == DCT_DCT) {
        coef_probs  = fc->coef_probs_16x16[type];
        coef_counts = fc->coef_counts_16x16[type];
      } else {
        coef_probs  = fc->hybrid_coef_probs_16x16[type];
        coef_counts = fc->hybrid_coef_counts_16x16[type];
      }
      break;
  }

  VP9_COMBINEENTROPYCONTEXTS(pt, *a, *l);
  while (1) {
    int val;
    const uint8_t *cat6 = cat6_prob;
    if (c >= seg_eob) break;
    prob = coef_probs[coef_bands[c]][pt];
    if (!vp9_read(br, prob[EOB_CONTEXT_NODE]))
      break;
SKIP_START:
    if (c >= seg_eob) break;
    if (!vp9_read(br, prob[ZERO_CONTEXT_NODE])) {
      INCREMENT_COUNT(ZERO_TOKEN);
      ++c;
      prob = coef_probs[coef_bands[c]][pt];
      goto SKIP_START;
    }
    // ONE_CONTEXT_NODE_0_
    if (!vp9_read(br, prob[ONE_CONTEXT_NODE])) {
      WRITE_COEF_CONTINUE(1, ONE_TOKEN);
    }
    // LOW_VAL_CONTEXT_NODE_0_
    if (!vp9_read(br, prob[LOW_VAL_CONTEXT_NODE])) {
      if (!vp9_read(br, prob[TWO_CONTEXT_NODE])) {
        WRITE_COEF_CONTINUE(2, TWO_TOKEN);
      }
      if (!vp9_read(br, prob[THREE_CONTEXT_NODE])) {
        WRITE_COEF_CONTINUE(3, THREE_TOKEN);
      }
      WRITE_COEF_CONTINUE(4, FOUR_TOKEN);
    }
    // HIGH_LOW_CONTEXT_NODE_0_
    if (!vp9_read(br, prob[HIGH_LOW_CONTEXT_NODE])) {
      if (!vp9_read(br, prob[CAT_ONE_CONTEXT_NODE])) {
        val = CAT1_MIN_VAL;
        ADJUST_COEF(CAT1_PROB0, 0);
        WRITE_COEF_CONTINUE(val, DCT_VAL_CATEGORY1);
      }
      val = CAT2_MIN_VAL;
      ADJUST_COEF(CAT2_PROB1, 1);
      ADJUST_COEF(CAT2_PROB0, 0);
      WRITE_COEF_CONTINUE(val, DCT_VAL_CATEGORY2);
    }
    // CAT_THREEFOUR_CONTEXT_NODE_0_
    if (!vp9_read(br, prob[CAT_THREEFOUR_CONTEXT_NODE])) {
      if (!vp9_read(br, prob[CAT_THREE_CONTEXT_NODE])) {
        val = CAT3_MIN_VAL;
        ADJUST_COEF(CAT3_PROB2, 2);
        ADJUST_COEF(CAT3_PROB1, 1);
        ADJUST_COEF(CAT3_PROB0, 0);
        WRITE_COEF_CONTINUE(val, DCT_VAL_CATEGORY3);
      }
      val = CAT4_MIN_VAL;
      ADJUST_COEF(CAT4_PROB3, 3);
      ADJUST_COEF(CAT4_PROB2, 2);
      ADJUST_COEF(CAT4_PROB1, 1);
      ADJUST_COEF(CAT4_PROB0, 0);
      WRITE_COEF_CONTINUE(val, DCT_VAL_CATEGORY4);
    }
    // CAT_FIVE_CONTEXT_NODE_0_:
    if (!vp9_read(br, prob[CAT_FIVE_CONTEXT_NODE])) {
      val = CAT5_MIN_VAL;
      ADJUST_COEF(CAT5_PROB4, 4);
      ADJUST_COEF(CAT5_PROB3, 3);
      ADJUST_COEF(CAT5_PROB2, 2);
      ADJUST_COEF(CAT5_PROB1, 1);
      ADJUST_COEF(CAT5_PROB0, 0);
      WRITE_COEF_CONTINUE(val, DCT_VAL_CATEGORY5);
    }
    val = 0;
    while (*cat6) {
      val = (val << 1) | vp9_read(br, *cat6++);
    }
    val += CAT6_MIN_VAL;
    WRITE_COEF_CONTINUE(val, DCT_VAL_CATEGORY6);
  }

  if (c < seg_eob)
    coef_counts[coef_bands[c]][pt][DCT_EOB_TOKEN]++;

  a[0] = l[0] = (c != !type);

  return c;
}

static int get_eob(MACROBLOCKD* const xd, int segment_id, int eob_max) {
  int active = vp9_segfeature_active(xd, segment_id, SEG_LVL_EOB);
  int eob = vp9_get_segdata(xd, segment_id, SEG_LVL_EOB);

  if (!active || eob > eob_max)
    eob = eob_max;
  return eob;
}


static int vp9_decode_mb_tokens_16x16(VP9D_COMP* const pbi,
                                      MACROBLOCKD* const xd,
                                      BOOL_DECODER* const bc) {
  ENTROPY_CONTEXT* const A = (ENTROPY_CONTEXT *)xd->above_context;
  ENTROPY_CONTEXT* const L = (ENTROPY_CONTEXT *)xd->left_context;
  unsigned short* const eobs = xd->eobs;
  const int segment_id = xd->mode_info_context->mbmi.segment_id;
  int c, i, eobtotal = 0, seg_eob;

  // Luma block
  eobs[0] = c = decode_coefs(pbi, xd, bc, A, L, PLANE_TYPE_Y_WITH_DC,
                             get_tx_type(xd, &xd->block[0]),
                             get_eob(xd, segment_id, 256),
                             xd->qcoeff, vp9_default_zig_zag1d_16x16,
                             TX_16X16, vp9_coef_bands_16x16);
  A[1] = A[2] = A[3] = A[0];
  L[1] = L[2] = L[3] = L[0];
  eobtotal += c;

  // 8x8 chroma blocks
  seg_eob = get_eob(xd, segment_id, 64);
  for (i = 16; i < 24; i += 4) {
    ENTROPY_CONTEXT* const a = A + vp9_block2above_8x8[i];
    ENTROPY_CONTEXT* const l = L + vp9_block2left_8x8[i];

    eobs[i] = c = decode_coefs(pbi, xd, bc, a, l, PLANE_TYPE_UV,
                               DCT_DCT, seg_eob, xd->block[i].qcoeff,
                               vp9_default_zig_zag1d_8x8,
                               TX_8X8, vp9_coef_bands_8x8);
    a[1] = a[0];
    l[1] = l[0];
    eobtotal += c;
  }

  // no Y2 block
  vpx_memset(&A[8], 0, sizeof(A[8]));
  vpx_memset(&L[8], 0, sizeof(L[8]));

  return eobtotal;
}

static int vp9_decode_mb_tokens_8x8(VP9D_COMP* const pbi,
                                    MACROBLOCKD* const xd,
                                    BOOL_DECODER* const bc) {
  ENTROPY_CONTEXT *const A = (ENTROPY_CONTEXT *)xd->above_context;
  ENTROPY_CONTEXT *const L = (ENTROPY_CONTEXT *)xd->left_context;
  unsigned short *const eobs = xd->eobs;
  PLANE_TYPE type;
  int c, i, eobtotal = 0, seg_eob;
  const int segment_id = xd->mode_info_context->mbmi.segment_id;

  // 2nd order DC block
  if (xd->mode_info_context->mbmi.mode != B_PRED &&
      xd->mode_info_context->mbmi.mode != SPLITMV &&
      xd->mode_info_context->mbmi.mode != I8X8_PRED) {
    ENTROPY_CONTEXT *const a = A + vp9_block2above_8x8[24];
    ENTROPY_CONTEXT *const l = L + vp9_block2left_8x8[24];

    eobs[24] = c = decode_coefs(pbi, xd, bc, a, l, PLANE_TYPE_Y2,
                                DCT_DCT, get_eob(xd, segment_id, 4),
                                xd->block[24].qcoeff,
                                vp9_default_zig_zag1d, TX_8X8, vp9_coef_bands);
    eobtotal += c - 4;
    type = PLANE_TYPE_Y_NO_DC;
  } else {
    type = PLANE_TYPE_Y_WITH_DC;
  }

  // luma blocks
  seg_eob = get_eob(xd, segment_id, 64);
  for (i = 0; i < 16; i += 4) {
    ENTROPY_CONTEXT *const a = A + vp9_block2above_8x8[i];
    ENTROPY_CONTEXT *const l = L + vp9_block2left_8x8[i];

    eobs[i] = c = decode_coefs(pbi, xd, bc, a, l, type,
                               type == PLANE_TYPE_Y_WITH_DC ?
                                 get_tx_type(xd, xd->block + i) : DCT_DCT,
                               seg_eob, xd->block[i].qcoeff,
                               vp9_default_zig_zag1d_8x8,
                               TX_8X8, vp9_coef_bands_8x8);
    a[1] = a[0];
    l[1] = l[0];
    eobtotal += c;
  }

  // chroma blocks
  if (xd->mode_info_context->mbmi.mode == I8X8_PRED ||
      xd->mode_info_context->mbmi.mode == SPLITMV) {
    // use 4x4 transform for U, V components in I8X8/splitmv prediction mode
    seg_eob = get_eob(xd, segment_id, 16);
    for (i = 16; i < 24; i++) {
      ENTROPY_CONTEXT *const a = A + vp9_block2above[i];
      ENTROPY_CONTEXT *const l = L + vp9_block2left[i];

      eobs[i] = c = decode_coefs(pbi, xd, bc, a, l, PLANE_TYPE_UV,
                                 DCT_DCT, seg_eob, xd->block[i].qcoeff,
                                 vp9_default_zig_zag1d, TX_4X4, vp9_coef_bands);
      eobtotal += c;
    }
  } else {
    for (i = 16; i < 24; i += 4) {
      ENTROPY_CONTEXT *const a = A + vp9_block2above_8x8[i];
      ENTROPY_CONTEXT *const l = L + vp9_block2left_8x8[i];

      eobs[i] = c = decode_coefs(pbi, xd, bc, a, l, PLANE_TYPE_UV,
                                 DCT_DCT, seg_eob, xd->block[i].qcoeff,
                                 vp9_default_zig_zag1d_8x8,
                                 TX_8X8, vp9_coef_bands_8x8);
      a[1] = a[0];
      l[1] = l[0];
      eobtotal += c;
    }
  }

  return eobtotal;
}

int vp9_decode_coefs_4x4(VP9D_COMP *dx, MACROBLOCKD *xd,
                         BOOL_DECODER* const bc,
                         PLANE_TYPE type, int i) {
  ENTROPY_CONTEXT *const A = (ENTROPY_CONTEXT *)xd->above_context;
  ENTROPY_CONTEXT *const L = (ENTROPY_CONTEXT *)xd->left_context;
  ENTROPY_CONTEXT *const a = A + vp9_block2above[i];
  ENTROPY_CONTEXT *const l = L + vp9_block2left[i];
  INT16 *qcoeff_ptr = &xd->qcoeff[0];
  const int *scan = vp9_default_zig_zag1d;
  unsigned short *const eobs = xd->eobs;
  int segment_id = xd->mode_info_context->mbmi.segment_id;
  int c, seg_eob = get_eob(xd, segment_id, 16);
  TX_TYPE tx_type = DCT_DCT;

  if (type == PLANE_TYPE_Y_WITH_DC)
    tx_type = get_tx_type(xd, &xd->block[i]);
  switch (tx_type) {
    case ADST_DCT :
      scan = vp9_row_scan;
      break;

    case DCT_ADST :
      scan = vp9_col_scan;
      break;

    default :
      scan = vp9_default_zig_zag1d;
      break;
  }
  eobs[i] = c = decode_coefs(dx, xd, bc, a, l, type,
                             tx_type, seg_eob, qcoeff_ptr + i * 16,
                             scan, TX_4X4, vp9_coef_bands);
  return c;
}

int vp9_decode_mb_tokens_4x4_uv(VP9D_COMP* const dx,
                                MACROBLOCKD* const xd,
                                BOOL_DECODER* const bc) {
  int eobtotal = 0, i;

  for (i = 16; i < 24; i++)
    eobtotal += vp9_decode_coefs_4x4(dx, xd, bc, PLANE_TYPE_UV, i);

  return eobtotal;
}

static int vp9_decode_mb_tokens_4x4(VP9D_COMP* const dx,
                                    MACROBLOCKD* const xd,
                                    BOOL_DECODER* const bc) {
  int i, eobtotal = 0;
  PLANE_TYPE type;

  if (xd->mode_info_context->mbmi.mode != B_PRED &&
      xd->mode_info_context->mbmi.mode != I8X8_PRED &&
      xd->mode_info_context->mbmi.mode != SPLITMV) {
    eobtotal += vp9_decode_coefs_4x4(dx, xd, bc, PLANE_TYPE_Y2, 24) - 16;
    type = PLANE_TYPE_Y_NO_DC;
  } else {
    type = PLANE_TYPE_Y_WITH_DC;
  }

  for (i = 0; i < 16; ++i) {
    eobtotal += vp9_decode_coefs_4x4(dx, xd, bc, type, i);
  }

  return eobtotal + vp9_decode_mb_tokens_4x4_uv(dx, xd, bc);
}

int vp9_decode_mb_tokens(VP9D_COMP* const dx,
                         MACROBLOCKD* const xd,
                         BOOL_DECODER* const bc) {
  const TX_SIZE tx_size = xd->mode_info_context->mbmi.txfm_size;
  int eobtotal;

  if (tx_size == TX_16X16) {
    eobtotal = vp9_decode_mb_tokens_16x16(dx, xd, bc);
  } else if (tx_size == TX_8X8) {
    eobtotal = vp9_decode_mb_tokens_8x8(dx, xd, bc);
  } else {
    assert(tx_size == TX_4X4);
    eobtotal = vp9_decode_mb_tokens_4x4(dx, xd, bc);
  }

  return eobtotal;
}