text: /*
   * VC-1 and WMV3 decoder
   * Copyright (c) 2011 Mashiat Sarker Shakkhar
   * Copyright (c) 2006-2007 Konstantin Shishkov
   * Partly based on vc9.c (c) 2005 Anonymous, Alex Beregszaszi, Michael Niedermayer
   *
   * This file is part of FFmpeg.
   *
   * FFmpeg is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * FFmpeg is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with FFmpeg; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
   */
  
  /**
   * @file
   * VC-1 and WMV3 block decoding routines
   */
  
  #include "avcodec.h"
  #include "mpegutils.h"
  #include "mpegvideo.h"
  #include "msmpeg4data.h"
  #include "unary.h"
  #include "vc1.h"
  #include "vc1_pred.h"
  #include "vc1acdata.h"
  #include "vc1data.h"
  
  #define MB_INTRA_VLC_BITS 9
  #define DC_VLC_BITS 9
  
  // offset tables for interlaced picture MVDATA decoding
  static const uint8_t offset_table[2][9] = {
      {  0,  1,  2,  4,  8, 16, 32,  64, 128 },
      {  0,  1,  3,  7, 15, 31, 63, 127, 255 },
  };
  
  /***********************************************************************/
  /**
   * @name VC-1 Bitplane decoding
   * @see 8.7, p56
   * @{
   */
  
  
  static inline void init_block_index(VC1Context *v)
  {
      MpegEncContext *s = &v->s;
      ff_init_block_index(s);
      if (v->field_mode && !(v->second_field ^ v->tff)) {
          s->dest[0] += s->current_picture_ptr->f->linesize[0];
          s->dest[1] += s->current_picture_ptr->f->linesize[1];
          s->dest[2] += s->current_picture_ptr->f->linesize[2];
      }
  }
  
  /** @} */ //Bitplane group
  
  static void vc1_put_signed_blocks_clamped(VC1Context *v)
  {
      MpegEncContext *s = &v->s;
      int topleft_mb_pos, top_mb_pos;
      int stride_y, fieldtx = 0;
      int v_dist;
  
      /* The put pixels loop is always one MB row behind the decoding loop,
       * because we can only put pixels when overlap filtering is done, and
       * for filtering of the bottom edge of a MB, we need the next MB row
       * present as well.
       * Within the row, the put pixels loop is also one MB col behind the
       * decoding loop. The reason for this is again, because for filtering
       * of the right MB edge, we need the next MB present. */
      if (!s->first_slice_line) {
          if (s->mb_x) {
              topleft_mb_pos = (s->mb_y - 1) * s->mb_stride + s->mb_x - 1;
              if (v->fcm == ILACE_FRAME)
                  fieldtx = v->fieldtx_plane[topleft_mb_pos];
              stride_y       = s->linesize << fieldtx;
              v_dist         = (16 - fieldtx) >> (fieldtx == 0);
              s->idsp.put_signed_pixels_clamped(v->block[v->topleft_blk_idx][0],
                                                s->dest[0] - 16 * s->linesize - 16,
                                                stride_y);
              s->idsp.put_signed_pixels_clamped(v->block[v->topleft_blk_idx][1],
                                                s->dest[0] - 16 * s->linesize - 8,
                                                stride_y);
              s->idsp.put_signed_pixels_clamped(v->block[v->topleft_blk_idx][2],
                                                s->dest[0] - v_dist * s->linesize - 16,
                                                stride_y);
              s->idsp.put_signed_pixels_clamped(v->block[v->topleft_blk_idx][3],
                                                s->dest[0] - v_dist * s->linesize - 8,
                                                stride_y);
              s->idsp.put_signed_pixels_clamped(v->block[v->topleft_blk_idx][4],
                                                s->dest[1] - 8 * s->uvlinesize - 8,
                                                s->uvlinesize);
              s->idsp.put_signed_pixels_clamped(v->block[v->topleft_blk_idx][5],
                                                s->dest[2] - 8 * s->uvlinesize - 8,
                                                s->uvlinesize);
          }
          if (s->mb_x == s->mb_width - 1) {
              top_mb_pos = (s->mb_y - 1) * s->mb_stride + s->mb_x;
              if (v->fcm == ILACE_FRAME)
                  fieldtx = v->fieldtx_plane[top_mb_pos];
              stride_y   = s->linesize << fieldtx;
              v_dist     = fieldtx ? 15 : 8;
              s->idsp.put_signed_pixels_clamped(v->block[v->top_blk_idx][0],
                                                s->dest[0] - 16 * s->linesize,
                                                stride_y);
              s->idsp.put_signed_pixels_clamped(v->block[v->top_blk_idx][1],
                                                s->dest[0] - 16 * s->linesize + 8,
                                                stride_y);
              s->idsp.put_signed_pixels_clamped(v->block[v->top_blk_idx][2],
                                                s->dest[0] - v_dist * s->linesize,
                                                stride_y);
              s->idsp.put_signed_pixels_clamped(v->block[v->top_blk_idx][3],
                                                s->dest[0] - v_dist * s->linesize + 8,
                                                stride_y);
              s->idsp.put_signed_pixels_clamped(v->block[v->top_blk_idx][4],
                                                s->dest[1] - 8 * s->uvlinesize,
                                                s->uvlinesize);
              s->idsp.put_signed_pixels_clamped(v->block[v->top_blk_idx][5],
                                                s->dest[2] - 8 * s->uvlinesize,
                                                s->uvlinesize);
          }
      }
  
  #define inc_blk_idx(idx) do { \
          idx++; \
          if (idx >= v->n_allocated_blks) \
              idx = 0; \
      } while (0)
  
      inc_blk_idx(v->topleft_blk_idx);
      inc_blk_idx(v->top_blk_idx);
      inc_blk_idx(v->left_blk_idx);
      inc_blk_idx(v->cur_blk_idx);
  }
  
  /***********************************************************************/
  /**
   * @name VC-1 Block-level functions
   * @see 7.1.4, p91 and 8.1.1.7, p(1)04
   * @{
   */
  
  /**
   * @def GET_MQUANT
   * @brief Get macroblock-level quantizer scale
   */
  #define GET_MQUANT()                                           \
      if (v->dquantfrm) {                                        \
          int edges = 0;                                         \
          if (v->dqprofile == DQPROFILE_ALL_MBS) {               \
              if (v->dqbilevel) {                                \
                  mquant = (get_bits1(gb)) ? v->altpq : v->pq;   \
              } else {                                           \
                  mqdiff = get_bits(gb, 3);                      \
                  if (mqdiff != 7)                               \
                      mquant = v->pq + mqdiff;                   \
                  else                                           \
                      mquant = get_bits(gb, 5);                  \
              }                                                  \
          }                                                      \
          if (v->dqprofile == DQPROFILE_SINGLE_EDGE)             \
              edges = 1 << v->dqsbedge;                          \
          else if (v->dqprofile == DQPROFILE_DOUBLE_EDGES)       \
              edges = (3 << v->dqsbedge) % 15;                   \
          else if (v->dqprofile == DQPROFILE_FOUR_EDGES)         \
              edges = 15;                                        \
          if ((edges&1) && !s->mb_x)                             \
              mquant = v->altpq;                                 \
          if ((edges&2) && s->first_slice_line)                  \
              mquant = v->altpq;                                 \
          if ((edges&4) && s->mb_x == (s->mb_width - 1))         \
              mquant = v->altpq;                                 \
          if ((edges&8) && s->mb_y == (s->mb_height - 1))        \
              mquant = v->altpq;                                 \
          if (!mquant || mquant > 31) {                          \
              av_log(v->s.avctx, AV_LOG_ERROR,                   \
                     "Overriding invalid mquant %d\n", mquant);  \
              mquant = 1;                                        \
          }                                                      \
      }
  
  /**
   * @def GET_MVDATA(_dmv_x, _dmv_y)
   * @brief Get MV differentials
   * @see MVDATA decoding from 8.3.5.2, p(1)20
   * @param _dmv_x Horizontal differential for decoded MV
   * @param _dmv_y Vertical differential for decoded MV
   */
  #define GET_MVDATA(_dmv_x, _dmv_y)                                      \
      index = 1 + get_vlc2(gb, ff_vc1_mv_diff_vlc[s->mv_table_index].table, \
                           VC1_MV_DIFF_VLC_BITS, 2);                      \
      if (index > 36) {                                                   \
          mb_has_coeffs = 1;                                              \
          index -= 37;                                                    \
      } else                                                              \
          mb_has_coeffs = 0;                                              \
      s->mb_intra = 0;                                                    \
      if (!index) {                                                       \
          _dmv_x = _dmv_y = 0;                                            \
      } else if (index == 35) {                                           \
          _dmv_x = get_bits(gb, v->k_x - 1 + s->quarter_sample);          \
          _dmv_y = get_bits(gb, v->k_y - 1 + s->quarter_sample);          \
      } else if (index == 36) {                                           \
          _dmv_x = 0;                                                     \
          _dmv_y = 0;                                                     \
          s->mb_intra = 1;                                                \
      } else {                                                            \
          index1 = index % 6;                                             \
          _dmv_x = offset_table[1][index1];                               \
          val = size_table[index1] - (!s->quarter_sample && index1 == 5); \
          if (val > 0) {                                                  \
              val = get_bits(gb, val);                                    \
              sign = 0 - (val & 1);                                       \
              _dmv_x = (sign ^ ((val >> 1) + _dmv_x)) - sign;             \
          }                                                               \
                                                                          \
          index1 = index / 6;                                             \
          _dmv_y = offset_table[1][index1];                               \
          val = size_table[index1] - (!s->quarter_sample && index1 == 5); \
          if (val > 0) {                                                  \
              val = get_bits(gb, val);                                    \
              sign = 0 - (val & 1);                                       \
              _dmv_y = (sign ^ ((val >> 1) + _dmv_y)) - sign;             \
          }                                                               \
      }
  
  static av_always_inline void get_mvdata_interlaced(VC1Context *v, int *dmv_x,
                                                     int *dmv_y, int *pred_flag)
  {
      int index, index1;
      int extend_x, extend_y;
      GetBitContext *gb = &v->s.gb;
      int bits, esc;
      int val, sign;
  
      if (v->numref) {
          bits = VC1_2REF_MVDATA_VLC_BITS;
          esc  = 125;
      } else {
          bits = VC1_1REF_MVDATA_VLC_BITS;
          esc  = 71;
      }
      extend_x = v->dmvrange & 1;
      extend_y = (v->dmvrange >> 1) & 1;
      index = get_vlc2(gb, v->imv_vlc->table, bits, 3);
      if (index == esc) {
          *dmv_x = get_bits(gb, v->k_x);
          *dmv_y = get_bits(gb, v->k_y);
          if (v->numref) {
              if (pred_flag)
                  *pred_flag = *dmv_y & 1;
              *dmv_y = (*dmv_y + (*dmv_y & 1)) >> 1;
          }
      }
      else {
          av_assert0(index < esc);
          index1 = (index + 1) % 9;
          if (index1 != 0) {
              val    = get_bits(gb, index1 + extend_x);
              sign   = 0 - (val & 1);
              *dmv_x = (sign ^ ((val >> 1) + offset_table[extend_x][index1])) - sign;
          } else
              *dmv_x = 0;
          index1 = (index + 1) / 9;
          if (index1 > v->numref) {
              val    = get_bits(gb, (index1 >> v->numref) + extend_y);
              sign   = 0 - (val & 1);
              *dmv_y = (sign ^ ((val >> 1) + offset_table[extend_y][index1 >> v->numref])) - sign;
          } else
              *dmv_y = 0;
          if (v->numref && pred_flag)
              *pred_flag = index1 & 1;
      }
  }
  
  /** Reconstruct motion vector for B-frame and do motion compensation
   */
  static inline void vc1_b_mc(VC1Context *v, int dmv_x[2], int dmv_y[2],
                              int direct, int mode)
  {
      if (direct) {
          ff_vc1_mc_1mv(v, 0);
          ff_vc1_interp_mc(v);
          return;
      }
      if (mode == BMV_TYPE_INTERPOLATED) {
          ff_vc1_mc_1mv(v, 0);
          ff_vc1_interp_mc(v);
          return;
      }
  
      ff_vc1_mc_1mv(v, (mode == BMV_TYPE_BACKWARD));
  }
  
  /** Get predicted DC value for I-frames only
   * prediction dir: left=0, top=1
   * @param s MpegEncContext
   * @param overlap flag indicating that overlap filtering is used
   * @param pq integer part of picture quantizer
   * @param[in] n block index in the current MB
   * @param dc_val_ptr Pointer to DC predictor
   * @param dir_ptr Prediction direction for use in AC prediction
   */
  static inline int vc1_i_pred_dc(MpegEncContext *s, int overlap, int pq, int n,
                                  int16_t **dc_val_ptr, int *dir_ptr)
  {
      int a, b, c, wrap, pred, scale;
      int16_t *dc_val;
      static const uint16_t dcpred[32] = {
          -1, 1024,  512,  341,  256,  205,  171,  146,  128,
               114,  102,   93,   85,   79,   73,   68,   64,
                60,   57,   54,   51,   49,   47,   45,   43,
                41,   39,   38,   37,   35,   34,   33
      };
  
      /* find prediction - wmv3_dc_scale always used here in fact */
      if (n < 4) scale = s->y_dc_scale;
      else       scale = s->c_dc_scale;
  
      wrap   = s->block_wrap[n];
      dc_val = s->dc_val[0] + s->block_index[n];
  
      /* B A
       * C X
       */
      c = dc_val[ - 1];
      b = dc_val[ - 1 - wrap];
      a = dc_val[ - wrap];
  
      if (pq < 9 || !overlap) {
          /* Set outer values */
          if (s->first_slice_line && (n != 2 && n != 3))
              b = a = dcpred[scale];
          if (s->mb_x == 0 && (n != 1 && n != 3))
              b = c = dcpred[scale];
      } else {
          /* Set outer values */
          if (s->first_slice_line && (n != 2 && n != 3))
              b = a = 0;
          if (s->mb_x == 0 && (n != 1 && n != 3))
              b = c = 0;
      }
  
      if (abs(a - b) <= abs(b - c)) {
          pred     = c;
          *dir_ptr = 1; // left
      } else {
          pred     = a;
          *dir_ptr = 0; // top
      }
  
      /* update predictor */
      *dc_val_ptr = &dc_val[0];
      return pred;
  }
  
  
  /** Get predicted DC value
   * prediction dir: left=0, top=1
   * @param s MpegEncContext
   * @param overlap flag indicating that overlap filtering is used
   * @param pq integer part of picture quantizer
   * @param[in] n block index in the current MB
   * @param a_avail flag indicating top block availability
   * @param c_avail flag indicating left block availability
   * @param dc_val_ptr Pointer to DC predictor
   * @param dir_ptr Prediction direction for use in AC prediction
   */
  static inline int ff_vc1_pred_dc(MpegEncContext *s, int overlap, int pq, int n,
                                int a_avail, int c_avail,
                                int16_t **dc_val_ptr, int *dir_ptr)
  {
      int a, b, c, wrap, pred;
      int16_t *dc_val;
      int mb_pos = s->mb_x + s->mb_y * s->mb_stride;
      int q1, q2 = 0;
      int dqscale_index;
  
      /* scale predictors if needed */
      q1 = s->current_picture.qscale_table[mb_pos];
      dqscale_index = s->y_dc_scale_table[q1] - 1;
      if (dqscale_index < 0)
          return 0;
  
      wrap = s->block_wrap[n];
      dc_val = s->dc_val[0] + s->block_index[n];
  
      /* B A
       * C X
       */
      c = dc_val[ - 1];
      b = dc_val[ - 1 - wrap];
      a = dc_val[ - wrap];
  
      if (c_avail && (n != 1 && n != 3)) {
          q2 = s->current_picture.qscale_table[mb_pos - 1];
          if (q2 && q2 != q1)
              c = (c * s->y_dc_scale_table[q2] * ff_vc1_dqscale[dqscale_index] + 0x20000) >> 18;
      }
      if (a_avail && (n != 2 && n != 3)) {
          q2 = s->current_picture.qscale_table[mb_pos - s->mb_stride];
          if (q2 && q2 != q1)
              a = (a * s->y_dc_scale_table[q2] * ff_vc1_dqscale[dqscale_index] + 0x20000) >> 18;
      }
      if (a_avail && c_avail && (n != 3)) {
          int off = mb_pos;
          if (n != 1)
              off--;
          if (n != 2)
              off -= s->mb_stride;
          q2 = s->current_picture.qscale_table[off];
          if (q2 && q2 != q1)
              b = (b * s->y_dc_scale_table[q2] * ff_vc1_dqscale[dqscale_index] + 0x20000) >> 18;
      }
  
      if (c_avail && (!a_avail || abs(a - b) <= abs(b - c))) {
          pred     = c;
          *dir_ptr = 1; // left
      } else if (a_avail) {
          pred     = a;
          *dir_ptr = 0; // top
      } else {
          pred     = 0;
          *dir_ptr = 1; // left
      }
  
      /* update predictor */
      *dc_val_ptr = &dc_val[0];
      return pred;
  }
  
  /** @} */ // Block group
  
  /**
   * @name VC1 Macroblock-level functions in Simple/Main Profiles
   * @see 7.1.4, p91 and 8.1.1.7, p(1)04
   * @{
   */
  
  static inline int vc1_coded_block_pred(MpegEncContext * s, int n,
                                         uint8_t **coded_block_ptr)
  {
      int xy, wrap, pred, a, b, c;
  
      xy   = s->block_index[n];
      wrap = s->b8_stride;
  
      /* B C
       * A X
       */
      a = s->coded_block[xy - 1       ];
      b = s->coded_block[xy - 1 - wrap];
      c = s->coded_block[xy     - wrap];
  
      if (b == c) {
          pred = a;
      } else {
          pred = c;
      }
  
      /* store value */
      *coded_block_ptr = &s->coded_block[xy];
  
      return pred;
  }
  
  /**
   * Decode one AC coefficient
   * @param v The VC1 context
   * @param last Last coefficient
   * @param skip How much zero coefficients to skip
   * @param value Decoded AC coefficient value
   * @param codingset set of VLC to decode data
   * @see 8.1.3.4
   */
  static void vc1_decode_ac_coeff(VC1Context *v, int *last, int *skip,
                                  int *value, int codingset)
  {
      GetBitContext *gb = &v->s.gb;
      int index, run, level, lst, sign;
  
      index = get_vlc2(gb, ff_vc1_ac_coeff_table[codingset].table, AC_VLC_BITS, 3);
      if (index != ff_vc1_ac_sizes[codingset] - 1) {
          run   = vc1_index_decode_table[codingset][index][0];
          level = vc1_index_decode_table[codingset][index][1];
          lst   = index >= vc1_last_decode_table[codingset] || get_bits_left(gb) < 0;
          sign  = get_bits1(gb);
      } else {
          int escape = decode210(gb);
          if (escape != 2) {
              index = get_vlc2(gb, ff_vc1_ac_coeff_table[codingset].table, AC_VLC_BITS, 3);
              run   = vc1_index_decode_table[codingset][index][0];
              level = vc1_index_decode_table[codingset][index][1];
              lst   = index >= vc1_last_decode_table[codingset];
              if (escape == 0) {
                  if (lst)
                      level += vc1_last_delta_level_table[codingset][run];
                  else
                      level += vc1_delta_level_table[codingset][run];
              } else {
                  if (lst)
                      run += vc1_last_delta_run_table[codingset][level] + 1;
                  else
                      run += vc1_delta_run_table[codingset][level] + 1;
              }
              sign = get_bits1(gb);
          } else {
              lst = get_bits1(gb);
              if (v->s.esc3_level_length == 0) {
                  if (v->pq < 8 || v->dquantfrm) { // table 59
                      v->s.esc3_level_length = get_bits(gb, 3);
                      if (!v->s.esc3_level_length)
                          v->s.esc3_level_length = get_bits(gb, 2) + 8;
                  } else { // table 60
                      v->s.esc3_level_length = get_unary(gb, 1, 6) + 2;
                  }
                  v->s.esc3_run_length = 3 + get_bits(gb, 2);
              }
              run   = get_bits(gb, v->s.esc3_run_length);
              sign  = get_bits1(gb);
              level = get_bits(gb, v->s.esc3_level_length);
          }
      }
  
      *last  = lst;
      *skip  = run;
      *value = (level ^ -sign) + sign;
  }
  
  /** Decode intra block in intra frames - should be faster than decode_intra_block
   * @param v VC1Context
   * @param block block to decode
   * @param[in] n subblock index
   * @param coded are AC coeffs present or not
   * @param codingset set of VLC to decode data
   */
  static int vc1_decode_i_block(VC1Context *v, int16_t block[64], int n,
                                int coded, int codingset)
  {
      GetBitContext *gb = &v->s.gb;
      MpegEncContext *s = &v->s;
      int dc_pred_dir = 0; /* Direction of the DC prediction used */
      int i;
      int16_t *dc_val;
      int16_t *ac_val, *ac_val2;
      int dcdiff, scale;
  
      /* Get DC differential */
      if (n < 4) {
          dcdiff = get_vlc2(&s->gb, ff_msmp4_dc_luma_vlc[s->dc_table_index].table, DC_VLC_BITS, 3);
      } else {
          dcdiff = get_vlc2(&s->gb, ff_msmp4_dc_chroma_vlc[s->dc_table_index].table, DC_VLC_BITS, 3);
      }
      if (dcdiff < 0) {
          av_log(s->avctx, AV_LOG_ERROR, "Illegal DC VLC\n");
          return -1;
      }
      if (dcdiff) {
          const int m = (v->pq == 1 || v->pq == 2) ? 3 - v->pq : 0;
          if (dcdiff == 119 /* ESC index value */) {
              dcdiff = get_bits(gb, 8 + m);
          } else {
              if (m)
                  dcdiff = (dcdiff << m) + get_bits(gb, m) - ((1 << m) - 1);
          }
          if (get_bits1(gb))
              dcdiff = -dcdiff;
      }
  
      /* Prediction */
      dcdiff += vc1_i_pred_dc(&v->s, v->overlap, v->pq, n, &dc_val, &dc_pred_dir);
      *dc_val = dcdiff;
  
      /* Store the quantized DC coeff, used for prediction */
      if (n < 4)
          scale = s->y_dc_scale;
      else
          scale = s->c_dc_scale;
      block[0] = dcdiff * scale;
  
      ac_val  = s->ac_val[0][0] + s->block_index[n] * 16;
      ac_val2 = ac_val;
      if (dc_pred_dir) // left
          ac_val -= 16;
      else // top
          ac_val -= 16 * s->block_wrap[n];
  
      scale = v->pq * 2 + v->halfpq;
  
      //AC Decoding
      i = !!coded;
  
      if (coded) {
          int last = 0, skip, value;
          const uint8_t *zz_table;
          int k;
  
          if (v->s.ac_pred) {
              if (!dc_pred_dir)
                  zz_table = v->zz_8x8[2];
              else
                  zz_table = v->zz_8x8[3];
          } else
              zz_table = v->zz_8x8[1];
  
          while (!last) {
              vc1_decode_ac_coeff(v, &last, &skip, &value, codingset);
              i += skip;
              if (i > 63)
                  break;
              block[zz_table[i++]] = value;
          }
  
          /* apply AC prediction if needed */
          if (s->ac_pred) {
              int sh;
              if (dc_pred_dir) { // left
                  sh = v->left_blk_sh;
              } else { // top
                  sh = v->top_blk_sh;
                  ac_val += 8;
              }
              for (k = 1; k < 8; k++)
                  block[k << sh] += ac_val[k];
          }
          /* save AC coeffs for further prediction */
          for (k = 1; k < 8; k++) {
              ac_val2[k]     = block[k << v->left_blk_sh];
              ac_val2[k + 8] = block[k << v->top_blk_sh];
          }
  
          /* scale AC coeffs */
          for (k = 1; k < 64; k++)
              if (block[k]) {
                  block[k] *= scale;
                  if (!v->pquantizer)
                      block[k] += (block[k] < 0) ? -v->pq : v->pq;
              }
  
      } else {
          int k;
  
          memset(ac_val2, 0, 16 * 2);
  
          /* apply AC prediction if needed */
          if (s->ac_pred) {
              int sh;
              if (dc_pred_dir) { //left
                  sh = v->left_blk_sh;
              } else { // top
                  sh = v->top_blk_sh;
                  ac_val  += 8;
                  ac_val2 += 8;
              }
              memcpy(ac_val2, ac_val, 8 * 2);
              for (k = 1; k < 8; k++) {
                  block[k << sh] = ac_val[k] * scale;
                  if (!v->pquantizer && block[k << sh])
                      block[k << sh] += (block[k << sh] < 0) ? -v->pq : v->pq;
              }
          }
      }
      if (s->ac_pred) i = 63;
      s->block_last_index[n] = i;
  
      return 0;
  }
  
  /** Decode intra block in intra frames - should be faster than decode_intra_block
   * @param v VC1Context
   * @param block block to decode
   * @param[in] n subblock number
   * @param coded are AC coeffs present or not
   * @param codingset set of VLC to decode data
   * @param mquant quantizer value for this macroblock
   */
  static int vc1_decode_i_block_adv(VC1Context *v, int16_t block[64], int n,
                                    int coded, int codingset, int mquant)
  {
      GetBitContext *gb = &v->s.gb;
      MpegEncContext *s = &v->s;
      int dc_pred_dir = 0; /* Direction of the DC prediction used */
      int i;
      int16_t *dc_val = NULL;
      int16_t *ac_val, *ac_val2;
      int dcdiff;
      int a_avail = v->a_avail, c_avail = v->c_avail;
      int use_pred = s->ac_pred;
      int scale;
      int q1, q2 = 0;
      int mb_pos = s->mb_x + s->mb_y * s->mb_stride;
  
      /* Get DC differential */
      if (n < 4) {
          dcdiff = get_vlc2(&s->gb, ff_msmp4_dc_luma_vlc[s->dc_table_index].table, DC_VLC_BITS, 3);
      } else {
          dcdiff = get_vlc2(&s->gb, ff_msmp4_dc_chroma_vlc[s->dc_table_index].table, DC_VLC_BITS, 3);
      }
      if (dcdiff < 0) {
          av_log(s->avctx, AV_LOG_ERROR, "Illegal DC VLC\n");
          return -1;
      }
      if (dcdiff) {
          const int m = (mquant == 1 || mquant == 2) ? 3 - mquant : 0;
          if (dcdiff == 119 /* ESC index value */) {
              dcdiff = get_bits(gb, 8 + m);
          } else {
              if (m)
                  dcdiff = (dcdiff << m) + get_bits(gb, m) - ((1 << m) - 1);
          }
          if (get_bits1(gb))
              dcdiff = -dcdiff;
      }
  
      /* Prediction */
      dcdiff += ff_vc1_pred_dc(&v->s, v->overlap, mquant, n, v->a_avail, v->c_avail, &dc_val, &dc_pred_dir);
      *dc_val = dcdiff;
  
      /* Store the quantized DC coeff, used for prediction */
      if (n < 4)
          scale = s->y_dc_scale;
      else
          scale = s->c_dc_scale;
      block[0] = dcdiff * scale;
  
      /* check if AC is needed at all */
      if (!a_avail && !c_avail)
          use_pred = 0;
  
      scale = mquant * 2 + ((mquant == v->pq) ? v->halfpq : 0);
  
      ac_val  = s->ac_val[0][0] + s->block_index[n] * 16;
      ac_val2 = ac_val;
      if (dc_pred_dir) // left
          ac_val -= 16;
      else // top
          ac_val -= 16 * s->block_wrap[n];
  
      q1 = s->current_picture.qscale_table[mb_pos];
      if (n == 3)
          q2 = q1;
      else if (dc_pred_dir) {
          if (n == 1)
              q2 = q1;
          else if (c_avail && mb_pos)
              q2 = s->current_picture.qscale_table[mb_pos - 1];
      } else {
          if (n == 2)
              q2 = q1;
          else if (a_avail && mb_pos >= s->mb_stride)
              q2 = s->current_picture.qscale_table[mb_pos - s->mb_stride];
      }
  
      //AC Decoding
      i = 1;
  
      if (coded) {
          int last = 0, skip, value;
          const uint8_t *zz_table;
          int k;
  
          if (v->s.ac_pred) {
              if (!use_pred && v->fcm == ILACE_FRAME) {
                  zz_table = v->zzi_8x8;
              } else {
                  if (!dc_pred_dir) // top
                      zz_table = v->zz_8x8[2];
                  else // left
                      zz_table = v->zz_8x8[3];
              }
          } else {
              if (v->fcm != ILACE_FRAME)
                  zz_table = v->zz_8x8[1];
              else
                  zz_table = v->zzi_8x8;
          }
  
          while (!last) {
              vc1_decode_ac_coeff(v, &last, &skip, &value, codingset);
              i += skip;
              if (i > 63)
                  break;
              block[zz_table[i++]] = value;
          }
  
          /* apply AC prediction if needed */
          if (use_pred) {
              int sh;
              if (dc_pred_dir) { // left
                  sh = v->left_blk_sh;
              } else { // top
                  sh = v->top_blk_sh;
                  ac_val += 8;
              }
              /* scale predictors if needed*/
              if (q2 && q1 != q2) {
                  q1 = q1 * 2 + ((q1 == v->pq) ? v->halfpq : 0) - 1;
                  if (q1 < 1)
                      return AVERROR_INVALIDDATA;
                  q2 = q2 * 2 + ((q2 == v->pq) ? v->halfpq : 0) - 1;
                  for (k = 1; k < 8; k++)
                      block[k << sh] += (ac_val[k] * q2 * ff_vc1_dqscale[q1 - 1] + 0x20000) >> 18;
              } else {
                  for (k = 1; k < 8; k++)
                      block[k << sh] += ac_val[k];
              }
          }
          /* save AC coeffs for further prediction */
          for (k = 1; k < 8; k++) {
              ac_val2[k    ] = block[k << v->left_blk_sh];
              ac_val2[k + 8] = block[k << v->top_blk_sh];
          }
  
          /* scale AC coeffs */
          for (k = 1; k < 64; k++)
              if (block[k]) {
                  block[k] *= scale;
                  if (!v->pquantizer)
                      block[k] += (block[k] < 0) ? -mquant : mquant;
              }
  
      } else { // no AC coeffs
          int k;
  
          memset(ac_val2, 0, 16 * 2);
  
          /* apply AC prediction if needed */
          if (use_pred) {
              int sh;
              if (dc_pred_dir) { // left
                  sh = v->left_blk_sh;
              } else { // top
                  sh = v->top_blk_sh;
                  ac_val  += 8;
                  ac_val2 += 8;
              }
              memcpy(ac_val2, ac_val, 8 * 2);
              if (q2 && q1 != q2) {
                  q1 = q1 * 2 + ((q1 == v->pq) ? v->halfpq : 0) - 1;
                  q2 = q2 * 2 + ((q2 == v->pq) ? v->halfpq : 0) - 1;
                  if (q1 < 1)
                      return AVERROR_INVALIDDATA;
                  for (k = 1; k < 8; k++)
                      ac_val2[k] = (ac_val2[k] * q2 * ff_vc1_dqscale[q1 - 1] + 0x20000) >> 18;
              }
              for (k = 1; k < 8; k++) {
                  block[k << sh] = ac_val2[k] * scale;
                  if (!v->pquantizer && block[k << sh])
                      block[k << sh] += (block[k << sh] < 0) ? -mquant : mquant;
              }
          }
      }
      if (use_pred) i = 63;
      s->block_last_index[n] = i;
  
      return 0;
  }
  
  /** Decode intra block in inter frames - more generic version than vc1_decode_i_block
   * @param v VC1Context
   * @param block block to decode
   * @param[in] n subblock index
   * @param coded are AC coeffs present or not
   * @param mquant block quantizer
   * @param codingset set of VLC to decode data
   */
  static int vc1_decode_intra_block(VC1Context *v, int16_t block[64], int n,
                                    int coded, int mquant, int codingset)
  {
      GetBitContext *gb = &v->s.gb;
      MpegEncContext *s = &v->s;
      int dc_pred_dir = 0; /* Direction of the DC prediction used */
      int i;
      int16_t *dc_val = NULL;
      int16_t *ac_val, *ac_val2;
      int dcdiff;
      int mb_pos = s->mb_x + s->mb_y * s->mb_stride;
      int a_avail = v->a_avail, c_avail = v->c_avail;
      int use_pred = s->ac_pred;
      int scale;
      int q1, q2 = 0;
  
      s->bdsp.clear_block(block);
  
      /* XXX: Guard against dumb values of mquant */
      mquant = av_clip_uintp2(mquant, 5);
  
      /* Set DC scale - y and c use the same */
      s->y_dc_scale = s->y_dc_scale_table[mquant];
      s->c_dc_scale = s->c_dc_scale_table[mquant];
  
      /* Get DC differential */
      if (n < 4) {
          dcdiff = get_vlc2(&s->gb, ff_msmp4_dc_luma_vlc[s->dc_table_index].table, DC_VLC_BITS, 3);
      } else {
          dcdiff = get_vlc2(&s->gb, ff_msmp4_dc_chroma_vlc[s->dc_table_index].table, DC_VLC_BITS, 3);
      }
      if (dcdiff < 0) {
          av_log(s->avctx, AV_LOG_ERROR, "Illegal DC VLC\n");
          return -1;
      }
      if (dcdiff) {
          const int m = (mquant == 1 || mquant == 2) ? 3 - mquant : 0;
          if (dcdiff == 119 /* ESC index value */) {
              dcdiff = get_bits(gb, 8 + m);
          } else {
              if (m)
                  dcdiff = (dcdiff << m) + get_bits(gb, m) - ((1 << m) - 1);
          }
          if (get_bits1(gb))
              dcdiff = -dcdiff;
      }
  
      /* Prediction */
      dcdiff += ff_vc1_pred_dc(&v->s, v->overlap, mquant, n, a_avail, c_avail, &dc_val, &dc_pred_dir);
      *dc_val = dcdiff;
  
      /* Store the quantized DC coeff, used for prediction */
  
      if (n < 4) {
          block[0] = dcdiff * s->y_dc_scale;
      } else {
          block[0] = dcdiff * s->c_dc_scale;
      }
  
      //AC Decoding
      i = 1;
  
      /* check if AC is needed at all and adjust direction if needed */
      if (!a_avail) dc_pred_dir = 1;
      if (!c_avail) dc_pred_dir = 0;
      if (!a_avail && !c_avail) use_pred = 0;
      ac_val = s->ac_val[0][0] + s->block_index[n] * 16;
      ac_val2 = ac_val;
  
      scale = mquant * 2 + v->halfpq;
  
      if (dc_pred_dir) //left
          ac_val -= 16;
      else //top
          ac_val -= 16 * s->block_wrap[n];
  
      q1 = s->current_picture.qscale_table[mb_pos];
      if (dc_pred_dir && c_avail && mb_pos)
          q2 = s->current_picture.qscale_table[mb_pos - 1];
      if (!dc_pred_dir && a_avail && mb_pos >= s->mb_stride)
          q2 = s->current_picture.qscale_table[mb_pos - s->mb_stride];
      if ( dc_pred_dir && n == 1)
          q2 = q1;
      if (!dc_pred_dir && n == 2)
          q2 = q1;
      if (n == 3) q2 = q1;
  
      if (coded) {
          int last = 0, skip, value;
          int k;
  
          while (!last) {
              vc1_decode_ac_coeff(v, &last, &skip, &value, codingset);
              i += skip;
              if (i > 63)
                  break;
              if (v->fcm == PROGRESSIVE)
                  block[v->zz_8x8[0][i++]] = value;
              else {
                  if (use_pred && (v->fcm == ILACE_FRAME)) {
                      if (!dc_pred_dir) // top
                          block[v->zz_8x8[2][i++]] = value;
                      else // left
                          block[v->zz_8x8[3][i++]] = value;
                  } else {
                      block[v->zzi_8x8[i++]] = value;
                  }
              }
          }
  
          /* apply AC prediction if needed */
          if (use_pred) {
              /* scale predictors if needed*/
              if (q2 && q1 != q2) {
                  q1 = q1 * 2 + ((q1 == v->pq) ? v->halfpq : 0) - 1;
                  q2 = q2 * 2 + ((q2 == v->pq) ? v->halfpq : 0) - 1;
  
                  if (q1 < 1)
                      return AVERROR_INVALIDDATA;
                  if (dc_pred_dir) { // left
                      for (k = 1; k < 8; k++)
                          block[k << v->left_blk_sh] += (ac_val[k] * q2 * ff_vc1_dqscale[q1 - 1] + 0x20000) >> 18;
                  } else { //top
                      for (k = 1; k < 8; k++)
                          block[k << v->top_blk_sh] += (ac_val[k + 8] * q2 * ff_vc1_dqscale[q1 - 1] + 0x20000) >> 18;
                  }
              } else {
                  if (dc_pred_dir) { // left
                      for (k = 1; k < 8; k++)
                          block[k << v->left_blk_sh] += ac_val[k];
                  } else { // top
                      for (k = 1; k < 8; k++)
                          block[k << v->top_blk_sh] += ac_val[k + 8];
                  }
              }
          }
          /* save AC coeffs for further prediction */
          for (k = 1; k < 8; k++) {
              ac_val2[k    ] = block[k << v->left_blk_sh];
              ac_val2[k + 8] = block[k << v->top_blk_sh];
          }
  
          /* scale AC coeffs */
          for (k = 1; k < 64; k++)
              if (block[k]) {
                  block[k] *= scale;
                  if (!v->pquantizer)
                      block[k] += (block[k] < 0) ? -mquant : mquant;
              }
  
          if (use_pred) i = 63;
      } else { // no AC coeffs
          int k;
  
          memset(ac_val2, 0, 16 * 2);
          if (dc_pred_dir) { // left
              if (use_pred) {
                  memcpy(ac_val2, ac_val, 8 * 2);
                  if (q2 && q1 != q2) {
                      q1 = q1 * 2 + ((q1 == v->pq) ? v->halfpq : 0) - 1;
                      q2 = q2 * 2 + ((q2 == v->pq) ? v->halfpq : 0) - 1;
                      if (q1 < 1)
                          return AVERROR_INVALIDDATA;
                      for (k = 1; k < 8; k++)
                          ac_val2[k] = (ac_val2[k] * q2 * ff_vc1_dqscale[q1 - 1] + 0x20000) >> 18;
                  }
              }
          } else { // top
              if (use_pred) {
                  memcpy(ac_val2 + 8, ac_val + 8, 8 * 2);
                  if (q2 && q1 != q2) {
                      q1 = q1 * 2 + ((q1 == v->pq) ? v->halfpq : 0) - 1;
                      q2 = q2 * 2 + ((q2 == v->pq) ? v->halfpq : 0) - 1;
                      if (q1 < 1)
                          return AVERROR_INVALIDDATA;
                      for (k = 1; k < 8; k++)
                          ac_val2[k + 8] = (ac_val2[k + 8] * q2 * ff_vc1_dqscale[q1 - 1] + 0x20000) >> 18;
                  }
              }
          }
  
          /* apply AC prediction if needed */
          if (use_pred) {
              if (dc_pred_dir) { // left
                  for (k = 1; k < 8; k++) {
                      block[k << v->left_blk_sh] = ac_val2[k] * scale;
                      if (!v->pquantizer && block[k << v->left_blk_sh])
                          block[k << v->left_blk_sh] += (block[k << v->left_blk_sh] < 0) ? -mquant : mquant;
                  }
              } else { // top
                  for (k = 1; k < 8; k++) {
                      block[k << v->top_blk_sh] = ac_val2[k + 8] * scale;
                      if (!v->pquantizer && block[k << v->top_blk_sh])
                          block[k << v->top_blk_sh] += (block[k << v->top_blk_sh] < 0) ? -mquant : mquant;
                  }
              }
              i = 63;
          }
      }
      s->block_last_index[n] = i;
  
      return 0;
  }
  
  /** Decode P block
   */
  static int vc1_decode_p_block(VC1Context *v, int16_t block[64], int n,
                                int mquant, int ttmb, int first_block,
                                uint8_t *dst, int linesize, int skip_block,
                                int *ttmb_out)
  {
      MpegEncContext *s = &v->s;
      GetBitContext *gb = &s->gb;
      int i, j;
      int subblkpat = 0;
      int scale, off, idx, last, skip, value;
      int ttblk = ttmb & 7;
      int pat = 0;
  
      s->bdsp.clear_block(block);
  
      if (ttmb == -1) {
          ttblk = ff_vc1_ttblk_to_tt[v->tt_index][get_vlc2(gb, ff_vc1_ttblk_vlc[v->tt_index].table, VC1_TTBLK_VLC_BITS, 1)];
      }
      if (ttblk == TT_4X4) {
          subblkpat = ~(get_vlc2(gb, ff_vc1_subblkpat_vlc[v->tt_index].table, VC1_SUBBLKPAT_VLC_BITS, 1) + 1);
      }
      if ((ttblk != TT_8X8 && ttblk != TT_4X4)
          && ((v->ttmbf || (ttmb != -1 && (ttmb & 8) && !first_block))
              || (!v->res_rtm_flag && !first_block))) {
          subblkpat = decode012(gb);
          if (subblkpat)
              subblkpat ^= 3; // swap decoded pattern bits
          if (ttblk == TT_8X4_TOP || ttblk == TT_8X4_BOTTOM)
              ttblk = TT_8X4;
          if (ttblk == TT_4X8_RIGHT || ttblk == TT_4X8_LEFT)
              ttblk = TT_4X8;
      }
      scale = 2 * mquant + ((v->pq == mquant) ? v->halfpq : 0);
  
      // convert transforms like 8X4_TOP to generic TT and SUBBLKPAT
      if (ttblk == TT_8X4_TOP || ttblk == TT_8X4_BOTTOM) {
          subblkpat = 2 - (ttblk == TT_8X4_TOP);
          ttblk     = TT_8X4;
      }
      if (ttblk == TT_4X8_RIGHT || ttblk == TT_4X8_LEFT) {
          subblkpat = 2 - (ttblk == TT_4X8_LEFT);
          ttblk     = TT_4X8;
      }
      switch (ttblk) {
      case TT_8X8:
          pat  = 0xF;
          i    = 0;
          last = 0;
          while (!last) {
              vc1_decode_ac_coeff(v, &last, &skip, &value, v->codingset2);
              i += skip;
              if (i > 63)
                  break;
              if (!v->fcm)
                  idx = v->zz_8x8[0][i++];
              else
                  idx = v->zzi_8x8[i++];
              block[idx] = value * scale;
              if (!v->pquantizer)
                  block[idx] += (block[idx] < 0) ? -mquant : mquant;
          }
          if (!skip_block) {
              if (i == 1)
                  v->vc1dsp.vc1_inv_trans_8x8_dc(dst, linesize, block);
              else {
                  v->vc1dsp.vc1_inv_trans_8x8(block);
                  s->idsp.add_pixels_clamped(block, dst, linesize);
              }
          }
          break;
      case TT_4X4:
          pat = ~subblkpat & 0xF;
          for (j = 0; j < 4; j++) {
              last = subblkpat & (1 << (3 - j));
              i    = 0;
              off  = (j & 1) * 4 + (j & 2) * 16;
              while (!last) {
                  vc1_decode_ac_coeff(v, &last, &skip, &value, v->codingset2);
                  i += skip;
                  if (i > 15)
                      break;
                  if (!v->fcm)
                      idx = ff_vc1_simple_progressive_4x4_zz[i++];
                  else
                      idx = ff_vc1_adv_interlaced_4x4_zz[i++];
                  block[idx + off] = value * scale;
                  if (!v->pquantizer)
                      block[idx + off] += (block[idx + off] < 0) ? -mquant : mquant;
              }
              if (!(subblkpat & (1 << (3 - j))) && !skip_block) {
                  if (i == 1)
                      v->vc1dsp.vc1_inv_trans_4x4_dc(dst + (j & 1) * 4 + (j & 2) * 2 * linesize, linesize, block + off);
                  else
                      v->vc1dsp.vc1_inv_trans_4x4(dst + (j & 1) * 4 + (j & 2) *  2 * linesize, linesize, block + off);
              }
          }
          break;
      case TT_8X4:
          pat = ~((subblkpat & 2) * 6 + (subblkpat & 1) * 3) & 0xF;
          for (j = 0; j < 2; j++) {
              last = subblkpat & (1 << (1 - j));
              i    = 0;
              off  = j * 32;
              while (!last) {
                  vc1_decode_ac_coeff(v, &last, &skip, &value, v->codingset2);
                  i += skip;
                  if (i > 31)
                      break;
                  if (!v->fcm)
                      idx = v->zz_8x4[i++] + off;
                  else
                      idx = ff_vc1_adv_interlaced_8x4_zz[i++] + off;
                  block[idx] = value * scale;
                  if (!v->pquantizer)
                      block[idx] += (block[idx] < 0) ? -mquant : mquant;
              }
              if (!(subblkpat & (1 << (1 - j))) && !skip_block) {
                  if (i == 1)
                      v->vc1dsp.vc1_inv_trans_8x4_dc(dst + j * 4 * linesize, linesize, block + off);
                  else
                      v->vc1dsp.vc1_inv_trans_8x4(dst + j * 4 * linesize, linesize, block + off);
              }
          }
          break;
      case TT_4X8:
          pat = ~(subblkpat * 5) & 0xF;
          for (j = 0; j < 2; j++) {
              last = subblkpat & (1 << (1 - j));
              i    = 0;
              off  = j * 4;
              while (!last) {
                  vc1_decode_ac_coeff(v, &last, &skip, &value, v->codingset2);
                  i += skip;
                  if (i > 31)
                      break;
                  if (!v->fcm)
                      idx = v->zz_4x8[i++] + off;
                  else
                      idx = ff_vc1_adv_interlaced_4x8_zz[i++] + off;
                  block[idx] = value * scale;
                  if (!v->pquantizer)
                      block[idx] += (block[idx] < 0) ? -mquant : mquant;
              }
              if (!(subblkpat & (1 << (1 - j))) && !skip_block) {
                  if (i == 1)
                      v->vc1dsp.vc1_inv_trans_4x8_dc(dst + j * 4, linesize, block + off);
                  else
                      v->vc1dsp.vc1_inv_trans_4x8(dst + j*4, linesize, block + off);
              }
          }
          break;
      }
      if (ttmb_out)
          *ttmb_out |= ttblk << (n * 4);
      return pat;
  }
  
  /** @} */ // Macroblock group
  
  static const uint8_t size_table[6] = { 0, 2, 3, 4,  5,  8 };
  
  /** Decode one P-frame MB
   */
  static int vc1_decode_p_mb(VC1Context *v)
  {
      MpegEncContext *s = &v->s;
      GetBitContext *gb = &s->gb;
      int i, j;
      int mb_pos = s->mb_x + s->mb_y * s->mb_stride;
      int cbp; /* cbp decoding stuff */
      int mqdiff, mquant; /* MB quantization */
      int ttmb = v->ttfrm; /* MB Transform type */
  
      int mb_has_coeffs = 1; /* last_flag */
      int dmv_x, dmv_y; /* Differential MV components */
      int index, index1; /* LUT indexes */
      int val, sign; /* temp values */
      int first_block = 1;
      int dst_idx, off;
      int skipped, fourmv;
      int block_cbp = 0, pat, block_tt = 0, block_intra = 0;
  
      mquant = v->pq; /* lossy initialization */
  
      if (v->mv_type_is_raw)
          fourmv = get_bits1(gb);
      else
          fourmv = v->mv_type_mb_plane[mb_pos];
      if (v->skip_is_raw)
          skipped = get_bits1(gb);
      else
          skipped = v->s.mbskip_table[mb_pos];
  
      if (!fourmv) { /* 1MV mode */
          if (!skipped) {
              GET_MVDATA(dmv_x, dmv_y);
  
              if (s->mb_intra) {
                  s->current_picture.motion_val[1][s->block_index[0]][0] = 0;
                  s->current_picture.motion_val[1][s->block_index[0]][1] = 0;
              }
              s->current_picture.mb_type[mb_pos] = s->mb_intra ? MB_TYPE_INTRA : MB_TYPE_16x16;
              ff_vc1_pred_mv(v, 0, dmv_x, dmv_y, 1, v->range_x, v->range_y, v->mb_type[0], 0, 0);
  
              /* FIXME Set DC val for inter block ? */
              if (s->mb_intra && !mb_has_coeffs) {
                  GET_MQUANT();
                  s->ac_pred = get_bits1(gb);
                  cbp        = 0;
              } else if (mb_has_coeffs) {
                  if (s->mb_intra)
                      s->ac_pred = get_bits1(gb);
                  cbp = get_vlc2(&v->s.gb, v->cbpcy_vlc->table, VC1_CBPCY_P_VLC_BITS, 2);
                  GET_MQUANT();
              } else {
                  mquant = v->pq;
                  cbp    = 0;
              }
              s->current_picture.qscale_table[mb_pos] = mquant;
  
              if (!v->ttmbf && !s->mb_intra && mb_has_coeffs)
                  ttmb = get_vlc2(gb, ff_vc1_ttmb_vlc[v->tt_index].table,
                                  VC1_TTMB_VLC_BITS, 2);
              if (!s->mb_intra) ff_vc1_mc_1mv(v, 0);
              dst_idx = 0;
              for (i = 0; i < 6; i++) {
                  s->dc_val[0][s->block_index[i]] = 0;
                  dst_idx += i >> 2;
                  val = ((cbp >> (5 - i)) & 1);
                  off = (i & 4) ? 0 : ((i & 1) * 8 + (i & 2) * 4 * s->linesize);
                  v->mb_type[0][s->block_index[i]] = s->mb_intra;
                  if (s->mb_intra) {
                      /* check if prediction blocks A and C are available */
                      v->a_avail = v->c_avail = 0;
                      if (i == 2 || i == 3 || !s->first_slice_line)
                          v->a_avail = v->mb_type[0][s->block_index[i] - s->block_wrap[i]];
                      if (i == 1 || i == 3 || s->mb_x)
                          v->c_avail = v->mb_type[0][s->block_index[i] - 1];
  
                      vc1_decode_intra_block(v, s->block[i], i, val, mquant,
                                             (i & 4) ? v->codingset2 : v->codingset);
                      if ((i>3) && (s->flags & CODEC_FLAG_GRAY))
                          continue;
                      v->vc1dsp.vc1_inv_trans_8x8(s->block[i]);
                      if (v->rangeredfrm)
                          for (j = 0; j < 64; j++)
                              s->block[i][j] <<= 1;
                      s->idsp.put_signed_pixels_clamped(s->block[i],
                                                        s->dest[dst_idx] + off,
                                                        i & 4 ? s->uvlinesize
                                                              : s->linesize);
                      if (v->pq >= 9 && v->overlap) {
                          if (v->c_avail)
                              v->vc1dsp.vc1_h_overlap(s->dest[dst_idx] + off, i & 4 ? s->uvlinesize : s->linesize);
                          if (v->a_avail)
                              v->vc1dsp.vc1_v_overlap(s->dest[dst_idx] + off, i & 4 ? s->uvlinesize : s->linesize);
                      }
                      block_cbp   |= 0xF << (i << 2);
                      block_intra |= 1 << i;
                  } else if (val) {
                      pat = vc1_decode_p_block(v, s->block[i], i, mquant, ttmb, first_block,
                                               s->dest[dst_idx] + off, (i & 4) ? s->uvlinesize : s->linesize,
                                               (i & 4) && (s->flags & CODEC_FLAG_GRAY), &block_tt);
                      block_cbp |= pat << (i << 2);
                      if (!v->ttmbf && ttmb < 8)
                          ttmb = -1;
                      first_block = 0;
                  }
              }
          } else { // skipped
              s->mb_intra = 0;
              for (i = 0; i < 6; i++) {
                  v->mb_type[0][s->block_index[i]] = 0;
                  s->dc_val[0][s->block_index[i]]  = 0;
              }
              s->current_picture.mb_type[mb_pos]      = MB_TYPE_SKIP;
              s->current_picture.qscale_table[mb_pos] = 0;
              ff_vc1_pred_mv(v, 0, 0, 0, 1, v->range_x, v->range_y, v->mb_type[0], 0, 0);
              ff_vc1_mc_1mv(v, 0);
          }
      } else { // 4MV mode
          if (!skipped /* unskipped MB */) {
              int intra_count = 0, coded_inter = 0;
              int is_intra[6], is_coded[6];
              /* Get CBPCY */
              cbp = get_vlc2(&v->s.gb, v->cbpcy_vlc->table, VC1_CBPCY_P_VLC_BITS, 2);
              for (i = 0; i < 6; i++) {
                  val = ((cbp >> (5 - i)) & 1);
                  s->dc_val[0][s->block_index[i]] = 0;
                  s->mb_intra                     = 0;
                  if (i < 4) {
                      dmv_x = dmv_y = 0;
                      s->mb_intra   = 0;
                      mb_has_coeffs = 0;
                      if (val) {
                          GET_MVDATA(dmv_x, dmv_y);
                      }
                      ff_vc1_pred_mv(v, i, dmv_x, dmv_y, 0, v->range_x, v->range_y, v->mb_type[0], 0, 0);
                      if (!s->mb_intra)
                          ff_vc1_mc_4mv_luma(v, i, 0, 0);
                      intra_count += s->mb_intra;
                      is_intra[i]  = s->mb_intra;
                      is_coded[i]  = mb_has_coeffs;
                  }
                  if (i & 4) {
                      is_intra[i] = (intra_count >= 3);
                      is_coded[i] = val;
                  }
                  if (i == 4)
                      ff_vc1_mc_4mv_chroma(v, 0);
                  v->mb_type[0][s->block_index[i]] = is_intra[i];
                  if (!coded_inter)
                      coded_inter = !is_intra[i] & is_coded[i];
              }
              // if there are no coded blocks then don't do anything more
              dst_idx = 0;
              if (!intra_count && !coded_inter)
                  goto end;
              GET_MQUANT();
              s->current_picture.qscale_table[mb_pos] = mquant;
              /* test if block is intra and has pred */
              {
                  int intrapred = 0;
                  for (i = 0; i < 6; i++)
                      if (is_intra[i]) {
                          if (((!s->first_slice_line || (i == 2 || i == 3)) && v->mb_type[0][s->block_index[i] - s->block_wrap[i]])
                              || ((s->mb_x || (i == 1 || i == 3)) && v->mb_type[0][s->block_index[i] - 1])) {
                              intrapred = 1;
                              break;
                          }
                      }
                  if (intrapred)
                      s->ac_pred = get_bits1(gb);
                  else
                      s->ac_pred = 0;
              }
              if (!v->ttmbf && coded_inter)
                  ttmb = get_vlc2(gb, ff_vc1_ttmb_vlc[v->tt_index].table, VC1_TTMB_VLC_BITS, 2);
              for (i = 0; i < 6; i++) {
                  dst_idx    += i >> 2;
                  off         = (i & 4) ? 0 : ((i & 1) * 8 + (i & 2) * 4 * s->linesize);
                  s->mb_intra = is_intra[i];
                  if (is_intra[i]) {
                      /* check if prediction blocks A and C are available */
                      v->a_avail = v->c_avail = 0;
                      if (i == 2 || i == 3 || !s->first_slice_line)
                          v->a_avail = v->mb_type[0][s->block_index[i] - s->block_wrap[i]];
                      if (i == 1 || i == 3 || s->mb_x)
                          v->c_avail = v->mb_type[0][s->block_index[i] - 1];
  
                      vc1_decode_intra_block(v, s->block[i], i, is_coded[i], mquant,
                                             (i & 4) ? v->codingset2 : v->codingset);
                      if ((i>3) && (s->flags & CODEC_FLAG_GRAY))
                          continue;
                      v->vc1dsp.vc1_inv_trans_8x8(s->block[i]);
                      if (v->rangeredfrm)
                          for (j = 0; j < 64; j++)
                              s->block[i][j] <<= 1;
                      s->idsp.put_signed_pixels_clamped(s->block[i],
                                                        s->dest[dst_idx] + off,
                                                        (i & 4) ? s->uvlinesize
                                                                : s->linesize);
                      if (v->pq >= 9 && v->overlap) {
                          if (v->c_avail)
                              v->vc1dsp.vc1_h_overlap(s->dest[dst_idx] + off, i & 4 ? s->uvlinesize : s->linesize);
                          if (v->a_avail)
                              v->vc1dsp.vc1_v_overlap(s->dest[dst_idx] + off, i & 4 ? s->uvlinesize : s->linesize);
                      }
                      block_cbp   |= 0xF << (i << 2);
                      block_intra |= 1 << i;
                  } else if (is_coded[i]) {
                      pat = vc1_decode_p_block(v, s->block[i], i, mquant, ttmb,
                                               first_block, s->dest[dst_idx] + off,
                                               (i & 4) ? s->uvlinesize : s->linesize,
                                               (i & 4) && (s->flags & CODEC_FLAG_GRAY),
                                               &block_tt);
                      block_cbp |= pat << (i << 2);
                      if (!v->ttmbf && ttmb < 8)
                          ttmb = -1;
                      first_block = 0;
                  }
              }
          } else { // skipped MB
              s->mb_intra                               = 0;
              s->current_picture.qscale_table[mb_pos] = 0;
              for (i = 0; i < 6; i++) {
                  v->mb_type[0][s->block_index[i]] = 0;
                  s->dc_val[0][s->block_index[i]]  = 0;
              }
              for (i = 0; i < 4; i++) {
                  ff_vc1_pred_mv(v, i, 0, 0, 0, v->range_x, v->range_y, v->mb_type[0], 0, 0);
                  ff_vc1_mc_4mv_luma(v, i, 0, 0);
              }
              ff_vc1_mc_4mv_chroma(v, 0);
              s->current_picture.qscale_table[mb_pos] = 0;
          }
      }
  end:
      v->cbp[s->mb_x]      = block_cbp;
      v->ttblk[s->mb_x]    = block_tt;
      v->is_intra[s->mb_x] = block_intra;
  
      return 0;
  }
  
  /* Decode one macroblock in an interlaced frame p picture */
  
  static int vc1_decode_p_mb_intfr(VC1Context *v)
  {
      MpegEncContext *s = &v->s;
      GetBitContext *gb = &s->gb;
      int i;
      int mb_pos = s->mb_x + s->mb_y * s->mb_stride;
      int cbp = 0; /* cbp decoding stuff */
      int mqdiff, mquant; /* MB quantization */
      int ttmb = v->ttfrm; /* MB Transform type */
  
      int mb_has_coeffs = 1; /* last_flag */
      int dmv_x, dmv_y; /* Differential MV components */
      int val; /* temp value */
      int first_block = 1;
      int dst_idx, off;
      int skipped, fourmv = 0, twomv = 0;
      int block_cbp = 0, pat, block_tt = 0;
      int idx_mbmode = 0, mvbp;
      int stride_y, fieldtx;
  
      mquant = v->pq; /* Lossy initialization */
  
      if (v->skip_is_raw)
          skipped = get_bits1(gb);
      else
          skipped = v->s.mbskip_table[mb_pos];
      if (!skipped) {
          if (v->fourmvswitch)
              idx_mbmode = get_vlc2(gb, v->mbmode_vlc->table, VC1_INTFR_4MV_MBMODE_VLC_BITS, 2); // try getting this done
          else
              idx_mbmode = get_vlc2(gb, v->mbmode_vlc->table, VC1_INTFR_NON4MV_MBMODE_VLC_BITS, 2); // in a single line
          switch (ff_vc1_mbmode_intfrp[v->fourmvswitch][idx_mbmode][0]) {
          /* store the motion vector type in a flag (useful later) */
          case MV_PMODE_INTFR_4MV:
              fourmv = 1;
              v->blk_mv_type[s->block_index[0]] = 0;
              v->blk_mv_type[s->block_index[1]] = 0;
              v->blk_mv_type[s->block_index[2]] = 0;
              v->blk_mv_type[s->block_index[3]] = 0;
              break;
          case MV_PMODE_INTFR_4MV_FIELD:
              fourmv = 1;
              v->blk_mv_type[s->block_index[0]] = 1;
              v->blk_mv_type[s->block_index[1]] = 1;
              v->blk_mv_type[s->block_index[2]] = 1;
              v->blk_mv_type[s->block_index[3]] = 1;
              break;
          case MV_PMODE_INTFR_2MV_FIELD:
              twomv = 1;
              v->blk_mv_type[s->block_index[0]] = 1;
              v->blk_mv_type[s->block_index[1]] = 1;
              v->blk_mv_type[s->block_index[2]] = 1;
              v->blk_mv_type[s->block_index[3]] = 1;
              break;
          case MV_PMODE_INTFR_1MV:
              v->blk_mv_type[s->block_index[0]] = 0;
              v->blk_mv_type[s->block_index[1]] = 0;
              v->blk_mv_type[s->block_index[2]] = 0;
              v->blk_mv_type[s->block_index[3]] = 0;
              break;
          }
          if (ff_vc1_mbmode_intfrp[v->fourmvswitch][idx_mbmode][0] == MV_PMODE_INTFR_INTRA) { // intra MB
              for (i = 0; i < 4; i++) {
                  s->current_picture.motion_val[1][s->block_index[i]][0] = 0;
                  s->current_picture.motion_val[1][s->block_index[i]][1] = 0;
              }
              v->is_intra[s->mb_x] = 0x3f; // Set the bitfield to all 1.
              s->mb_intra          = 1;
              s->current_picture.mb_type[mb_pos] = MB_TYPE_INTRA;
              fieldtx = v->fieldtx_plane[mb_pos] = get_bits1(gb);
              mb_has_coeffs = get_bits1(gb);
              if (mb_has_coeffs)
                  cbp = 1 + get_vlc2(&v->s.gb, v->cbpcy_vlc->table, VC1_CBPCY_P_VLC_BITS, 2);
              v->s.ac_pred = v->acpred_plane[mb_pos] = get_bits1(gb);
              GET_MQUANT();
              s->current_picture.qscale_table[mb_pos] = mquant;
              /* Set DC scale - y and c use the same (not sure if necessary here) */
              s->y_dc_scale = s->y_dc_scale_table[mquant];
              s->c_dc_scale = s->c_dc_scale_table[mquant];
              dst_idx = 0;
              for (i = 0; i < 6; i++) {
                  v->a_avail = v->c_avail          = 0;
                  v->mb_type[0][s->block_index[i]] = 1;
                  s->dc_val[0][s->block_index[i]]  = 0;
                  dst_idx += i >> 2;
                  val = ((cbp >> (5 - i)) & 1);
                  if (i == 2 || i == 3 || !s->first_slice_line)
                      v->a_avail = v->mb_type[0][s->block_index[i] - s->block_wrap[i]];
                  if (i == 1 || i == 3 || s->mb_x)
                      v->c_avail = v->mb_type[0][s->block_index[i] - 1];
  
                  vc1_decode_intra_block(v, s->block[i], i, val, mquant,
                                         (i & 4) ? v->codingset2 : v->codingset);
                  if ((i>3) && (s->flags & CODEC_FLAG_GRAY)) continue;
                  v->vc1dsp.vc1_inv_trans_8x8(s->block[i]);
                  if (i < 4) {
                      stride_y = s->linesize << fieldtx;
                      off = (fieldtx) ? ((i & 1) * 8) + ((i & 2) >> 1) * s->linesize : (i & 1) * 8 + 4 * (i & 2) * s->linesize;
                  } else {
                      stride_y = s->uvlinesize;
                      off = 0;
                  }
                  s->idsp.put_signed_pixels_clamped(s->block[i],
                                                    s->dest[dst_idx] + off,
                                                    stride_y);
                  //TODO: loop filter
              }
  
          } else { // inter MB
              mb_has_coeffs = ff_vc1_mbmode_intfrp[v->fourmvswitch][idx_mbmode][3];
              if (mb_has_coeffs)
                  cbp = 1 + get_vlc2(&v->s.gb, v->cbpcy_vlc->table, VC1_CBPCY_P_VLC_BITS, 2);
              if (ff_vc1_mbmode_intfrp[v->fourmvswitch][idx_mbmode][0] == MV_PMODE_INTFR_2MV_FIELD) {
                  v->twomvbp = get_vlc2(gb, v->twomvbp_vlc->table, VC1_2MV_BLOCK_PATTERN_VLC_BITS, 1);
              } else {
                  if ((ff_vc1_mbmode_intfrp[v->fourmvswitch][idx_mbmode][0] == MV_PMODE_INTFR_4MV)
                      || (ff_vc1_mbmode_intfrp[v->fourmvswitch][idx_mbmode][0] == MV_PMODE_INTFR_4MV_FIELD)) {
                      v->fourmvbp = get_vlc2(gb, v->fourmvbp_vlc->table, VC1_4MV_BLOCK_PATTERN_VLC_BITS, 1);
                  }
              }
              s->mb_intra = v->is_intra[s->mb_x] = 0;
              for (i = 0; i < 6; i++)
                  v->mb_type[0][s->block_index[i]] = 0;
              fieldtx = v->fieldtx_plane[mb_pos] = ff_vc1_mbmode_intfrp[v->fourmvswitch][idx_mbmode][1];
              /* for all motion vector read MVDATA and motion compensate each block */
              dst_idx = 0;
              if (fourmv) {
                  mvbp = v->fourmvbp;
                  for (i = 0; i < 4; i++) {
                      dmv_x = dmv_y = 0;
                      if (mvbp & (8 >> i))
                          get_mvdata_interlaced(v, &dmv_x, &dmv_y, 0);
                      ff_vc1_pred_mv_intfr(v, i, dmv_x, dmv_y, 0, v->range_x, v->range_y, v->mb_type[0], 0);
                      ff_vc1_mc_4mv_luma(v, i, 0, 0);
                  }
                  ff_vc1_mc_4mv_chroma4(v, 0, 0, 0);
              } else if (twomv) {
                  mvbp  = v->twomvbp;
                  dmv_x = dmv_y = 0;
                  if (mvbp & 2) {
                      get_mvdata_interlaced(v, &dmv_x, &dmv_y, 0);
                  }
                  ff_vc1_pred_mv_intfr(v, 0, dmv_x, dmv_y, 2, v->range_x, v->range_y, v->mb_type[0], 0);
                  ff_vc1_mc_4mv_luma(v, 0, 0, 0);
                  ff_vc1_mc_4mv_luma(v, 1, 0, 0);
                  dmv_x = dmv_y = 0;
                  if (mvbp & 1) {
                      get_mvdata_interlaced(v, &dmv_x, &dmv_y, 0);
                  }
                  ff_vc1_pred_mv_intfr(v, 2, dmv_x, dmv_y, 2, v->range_x, v->range_y, v->mb_type[0], 0);
                  ff_vc1_mc_4mv_luma(v, 2, 0, 0);
                  ff_vc1_mc_4mv_luma(v, 3, 0, 0);
                  ff_vc1_mc_4mv_chroma4(v, 0, 0, 0);
              } else {
                  mvbp = ff_vc1_mbmode_intfrp[v->fourmvswitch][idx_mbmode][2];
                  dmv_x = dmv_y = 0;
                  if (mvbp) {
                      get_mvdata_interlaced(v, &dmv_x, &dmv_y, 0);
                  }
                  ff_vc1_pred_mv_intfr(v, 0, dmv_x, dmv_y, 1, v->range_x, v->range_y, v->mb_type[0], 0);
                  ff_vc1_mc_1mv(v, 0);
              }
              if (cbp)
                  GET_MQUANT();  // p. 227
              s->current_picture.qscale_table[mb_pos] = mquant;
              if (!v->ttmbf && cbp)
                  ttmb = get_vlc2(gb, ff_vc1_ttmb_vlc[v->tt_index].table, VC1_TTMB_VLC_BITS, 2);
              for (i = 0; i < 6; i++) {
                  s->dc_val[0][s->block_index[i]] = 0;
                  dst_idx += i >> 2;
                  val = ((cbp >> (5 - i)) & 1);
                  if (!fieldtx)
                      off = (i & 4) ? 0 : ((i & 1) * 8 + (i & 2) * 4 * s->linesize);
                  else
                      off = (i & 4) ? 0 : ((i & 1) * 8 + ((i > 1) * s->linesize));
                  if (val) {
                      pat = vc1_decode_p_block(v, s->block[i], i, mquant, ttmb,
                                               first_block, s->dest[dst_idx] + off,
                                               (i & 4) ? s->uvlinesize : (s->linesize << fieldtx),
                                               (i & 4) && (s->flags & CODEC_FLAG_GRAY), &block_tt);
                      block_cbp |= pat << (i << 2);
                      if (!v->ttmbf && ttmb < 8)
                          ttmb = -1;
                      first_block = 0;
                  }
              }
          }
      } else { // skipped
          s->mb_intra = v->is_intra[s->mb_x] = 0;
          for (i = 0; i < 6; i++) {
              v->mb_type[0][s->block_index[i]] = 0;
              s->dc_val[0][s->block_index[i]] = 0;
          }
          s->current_picture.mb_type[mb_pos]      = MB_TYPE_SKIP;
          s->current_picture.qscale_table[mb_pos] = 0;
          v->blk_mv_type[s->block_index[0]] = 0;
          v->blk_mv_type[s->block_index[1]] = 0;
          v->blk_mv_type[s->block_index[2]] = 0;
          v->blk_mv_type[s->block_index[3]] = 0;
          ff_vc1_pred_mv_intfr(v, 0, 0, 0, 1, v->range_x, v->range_y, v->mb_type[0], 0);
          ff_vc1_mc_1mv(v, 0);
      }
      if (s->mb_x == s->mb_width - 1)
          memmove(v->is_intra_base, v->is_intra, sizeof(v->is_intra_base[0])*s->mb_stride);
      return 0;
  }
  
  static int vc1_decode_p_mb_intfi(VC1Context *v)
  {
      MpegEncContext *s = &v->s;
      GetBitContext *gb = &s->gb;
      int i;
      int mb_pos = s->mb_x + s->mb_y * s->mb_stride;
      int cbp = 0; /* cbp decoding stuff */
      int mqdiff, mquant; /* MB quantization */
      int ttmb = v->ttfrm; /* MB Transform type */
  
      int mb_has_coeffs = 1; /* last_flag */
      int dmv_x, dmv_y; /* Differential MV components */
      int val; /* temp values */
      int first_block = 1;
      int dst_idx, off;
      int pred_flag = 0;
      int block_cbp = 0, pat, block_tt = 0;
      int idx_mbmode = 0;
  
      mquant = v->pq; /* Lossy initialization */
  
      idx_mbmode = get_vlc2(gb, v->mbmode_vlc->table, VC1_IF_MBMODE_VLC_BITS, 2);
      if (idx_mbmode <= 1) { // intra MB
          v->is_intra[s->mb_x] = 0x3f; // Set the bitfield to all 1.
          s->mb_intra          = 1;
          s->current_picture.motion_val[1][s->block_index[0] + v->blocks_off][0] = 0;
          s->current_picture.motion_val[1][s->block_index[0] + v->blocks_off][1] = 0;
          s->current_picture.mb_type[mb_pos + v->mb_off] = MB_TYPE_INTRA;
          GET_MQUANT();
          s->current_picture.qscale_table[mb_pos] = mquant;
          /* Set DC scale - y and c use the same (not sure if necessary here) */
          s->y_dc_scale = s->y_dc_scale_table[mquant];
          s->c_dc_scale = s->c_dc_scale_table[mquant];
          v->s.ac_pred  = v->acpred_plane[mb_pos] = get_bits1(gb);
          mb_has_coeffs = idx_mbmode & 1;
          if (mb_has_coeffs)
              cbp = 1 + get_vlc2(&v->s.gb, v->cbpcy_vlc->table, VC1_ICBPCY_VLC_BITS, 2);
          dst_idx = 0;
          for (i = 0; i < 6; i++) {
              v->a_avail = v->c_avail          = 0;
              v->mb_type[0][s->block_index[i]] = 1;
              s->dc_val[0][s->block_index[i]]  = 0;
              dst_idx += i >> 2;
              val = ((cbp >> (5 - i)) & 1);
              if (i == 2 || i == 3 || !s->first_slice_line)
                  v->a_avail = v->mb_type[0][s->block_index[i] - s->block_wrap[i]];
              if (i == 1 || i == 3 || s->mb_x)
                  v->c_avail = v->mb_type[0][s->block_index[i] - 1];
  
              vc1_decode_intra_block(v, s->block[i], i, val, mquant,
                                     (i & 4) ? v->codingset2 : v->codingset);
              if ((i>3) && (s->flags & CODEC_FLAG_GRAY))
                  continue;
              v->vc1dsp.vc1_inv_trans_8x8(s->block[i]);
              off  = (i & 4) ? 0 : ((i & 1) * 8 + (i & 2) * 4 * s->linesize);
              s->idsp.put_signed_pixels_clamped(s->block[i],
                                                s->dest[dst_idx] + off,
                                                (i & 4) ? s->uvlinesize
                                                        : s->linesize);
              // TODO: loop filter
          }
      } else {
          s->mb_intra = v->is_intra[s->mb_x] = 0;
          s->current_picture.mb_type[mb_pos + v->mb_off] = MB_TYPE_16x16;
          for (i = 0; i < 6; i++)
              v->mb_type[0][s->block_index[i]] = 0;
          if (idx_mbmode <= 5) { // 1-MV
              dmv_x = dmv_y = pred_flag = 0;
              if (idx_mbmode & 1) {
                  get_mvdata_interlaced(v, &dmv_x, &dmv_y, &pred_flag);
              }
              ff_vc1_pred_mv(v, 0, dmv_x, dmv_y, 1, v->range_x, v->range_y, v->mb_type[0], pred_flag, 0);
              ff_vc1_mc_1mv(v, 0);
              mb_has_coeffs = !(idx_mbmode & 2);
          } else { // 4-MV
              v->fourmvbp = get_vlc2(gb, v->fourmvbp_vlc->table, VC1_4MV_BLOCK_PATTERN_VLC_BITS, 1);
              for (i = 0; i < 4; i++) {
                  dmv_x = dmv_y = pred_flag = 0;
                  if (v->fourmvbp & (8 >> i))
                      get_mvdata_interlaced(v, &dmv_x, &dmv_y, &pred_flag);
                  ff_vc1_pred_mv(v, i, dmv_x, dmv_y, 0, v->range_x, v->range_y, v->mb_type[0], pred_flag, 0);
                  ff_vc1_mc_4mv_luma(v, i, 0, 0);
              }
              ff_vc1_mc_4mv_chroma(v, 0);
              mb_has_coeffs = idx_mbmode & 1;
          }
          if (mb_has_coeffs)
              cbp = 1 + get_vlc2(&v->s.gb, v->cbpcy_vlc->table, VC1_CBPCY_P_VLC_BITS, 2);
          if (cbp) {
              GET_MQUANT();
          }
          s->current_picture.qscale_table[mb_pos] = mquant;
          if (!v->ttmbf && cbp) {
              ttmb = get_vlc2(gb, ff_vc1_ttmb_vlc[v->tt_index].table, VC1_TTMB_VLC_BITS, 2);
          }
          dst_idx = 0;
          for (i = 0; i < 6; i++) {
              s->dc_val[0][s->block_index[i]] = 0;
              dst_idx += i >> 2;
              val = ((cbp >> (5 - i)) & 1);
              off = (i & 4) ? 0 : (i & 1) * 8 + (i & 2) * 4 * s->linesize;
              if (val) {
                  pat = vc1_decode_p_block(v, s->block[i], i, mquant, ttmb,
                                           first_block, s->dest[dst_idx] + off,
                                           (i & 4) ? s->uvlinesize : s->linesize,
                                           (i & 4) && (s->flags & CODEC_FLAG_GRAY),
                                           &block_tt);
                  block_cbp |= pat << (i << 2);
                  if (!v->ttmbf && ttmb < 8)
                      ttmb = -1;
                  first_block = 0;
              }
          }
      }
      if (s->mb_x == s->mb_width - 1)
          memmove(v->is_intra_base, v->is_intra, sizeof(v->is_intra_base[0]) * s->mb_stride);
      return 0;
  }
  
  /** Decode one B-frame MB (in Main profile)
   */
  static void vc1_decode_b_mb(VC1Context *v)
  {
      MpegEncContext *s = &v->s;
      GetBitContext *gb = &s->gb;
      int i, j;
      int mb_pos = s->mb_x + s->mb_y * s->mb_stride;
      int cbp = 0; /* cbp decoding stuff */
      int mqdiff, mquant; /* MB quantization */
      int ttmb = v->ttfrm; /* MB Transform type */
      int mb_has_coeffs = 0; /* last_flag */
      int index, index1; /* LUT indexes */
      int val, sign; /* temp values */
      int first_block = 1;
      int dst_idx, off;
      int skipped, direct;
      int dmv_x[2], dmv_y[2];
      int bmvtype = BMV_TYPE_BACKWARD;
  
      mquant      = v->pq; /* lossy initialization */
      s->mb_intra = 0;
  
      if (v->dmb_is_raw)
          direct = get_bits1(gb);
      else
          direct = v->direct_mb_plane[mb_pos];
      if (v->skip_is_raw)
          skipped = get_bits1(gb);
      else
          skipped = v->s.mbskip_table[mb_pos];
  
      dmv_x[0] = dmv_x[1] = dmv_y[0] = dmv_y[1] = 0;
      for (i = 0; i < 6; i++) {
          v->mb_type[0][s->block_index[i]] = 0;
          s->dc_val[0][s->block_index[i]]  = 0;
      }
      s->current_picture.qscale_table[mb_pos] = 0;
  
      if (!direct) {
          if (!skipped) {
              GET_MVDATA(dmv_x[0], dmv_y[0]);
              dmv_x[1] = dmv_x[0];
              dmv_y[1] = dmv_y[0];
          }
          if (skipped || !s->mb_intra) {
              bmvtype = decode012(gb);
              switch (bmvtype) {
              case 0:
                  bmvtype = (v->bfraction >= (B_FRACTION_DEN/2)) ? BMV_TYPE_BACKWARD : BMV_TYPE_FORWARD;
                  break;
              case 1:
                  bmvtype = (v->bfraction >= (B_FRACTION_DEN/2)) ? BMV_TYPE_FORWARD : BMV_TYPE_BACKWARD;
                  break;
              case 2:
                  bmvtype  = BMV_TYPE_INTERPOLATED;
                  dmv_x[0] = dmv_y[0] = 0;
              }
          }
      }
      for (i = 0; i < 6; i++)
          v->mb_type[0][s->block_index[i]] = s->mb_intra;
  
      if (skipped) {
          if (direct)
              bmvtype = BMV_TYPE_INTERPOLATED;
          ff_vc1_pred_b_mv(v, dmv_x, dmv_y, direct, bmvtype);
          vc1_b_mc(v, dmv_x, dmv_y, direct, bmvtype);
          return;
      }
      if (direct) {
          cbp = get_vlc2(&v->s.gb, v->cbpcy_vlc->table, VC1_CBPCY_P_VLC_BITS, 2);
          GET_MQUANT();
          s->mb_intra = 0;
          s->current_picture.qscale_table[mb_pos] = mquant;
          if (!v->ttmbf)
              ttmb = get_vlc2(gb, ff_vc1_ttmb_vlc[v->tt_index].table, VC1_TTMB_VLC_BITS, 2);
          dmv_x[0] = dmv_y[0] = dmv_x[1] = dmv_y[1] = 0;
          ff_vc1_pred_b_mv(v, dmv_x, dmv_y, direct, bmvtype);
          vc1_b_mc(v, dmv_x, dmv_y, direct, bmvtype);
      } else {
          if (!mb_has_coeffs && !s->mb_intra) {
              /* no coded blocks - effectively skipped */
              ff_vc1_pred_b_mv(v, dmv_x, dmv_y, direct, bmvtype);
              vc1_b_mc(v, dmv_x, dmv_y, direct, bmvtype);
              return;
          }
          if (s->mb_intra && !mb_has_coeffs) {
              GET_MQUANT();
              s->current_picture.qscale_table[mb_pos] = mquant;
              s->ac_pred = get_bits1(gb);
              cbp = 0;
              ff_vc1_pred_b_mv(v, dmv_x, dmv_y, direct, bmvtype);
          } else {
              if (bmvtype == BMV_TYPE_INTERPOLATED) {
                  GET_MVDATA(dmv_x[0], dmv_y[0]);
                  if (!mb_has_coeffs) {
                      /* interpolated skipped block */
                      ff_vc1_pred_b_mv(v, dmv_x, dmv_y, direct, bmvtype);
                      vc1_b_mc(v, dmv_x, dmv_y, direct, bmvtype);
                      return;
                  }
              }
              ff_vc1_pred_b_mv(v, dmv_x, dmv_y, direct, bmvtype);
              if (!s->mb_intra) {
                  vc1_b_mc(v, dmv_x, dmv_y, direct, bmvtype);
              }
              if (s->mb_intra)
                  s->ac_pred = get_bits1(gb);
              cbp = get_vlc2(&v->s.gb, v->cbpcy_vlc->table, VC1_CBPCY_P_VLC_BITS, 2);
              GET_MQUANT();
              s->current_picture.qscale_table[mb_pos] = mquant;
              if (!v->ttmbf && !s->mb_intra && mb_has_coeffs)
                  ttmb = get_vlc2(gb, ff_vc1_ttmb_vlc[v->tt_index].table, VC1_TTMB_VLC_BITS, 2);
          }
      }
      dst_idx = 0;
      for (i = 0; i < 6; i++) {
          s->dc_val[0][s->block_index[i]] = 0;
          dst_idx += i >> 2;
          val = ((cbp >> (5 - i)) & 1);
          off = (i & 4) ? 0 : ((i & 1) * 8 + (i & 2) * 4 * s->linesize);
          v->mb_type[0][s->block_index[i]] = s->mb_intra;
          if (s->mb_intra) {
              /* check if prediction blocks A and C are available */
              v->a_avail = v->c_avail = 0;
              if (i == 2 || i == 3 || !s->first_slice_line)
                  v->a_avail = v->mb_type[0][s->block_index[i] - s->block_wrap[i]];
              if (i == 1 || i == 3 || s->mb_x)
                  v->c_avail = v->mb_type[0][s->block_index[i] - 1];
  
              vc1_decode_intra_block(v, s->block[i], i, val, mquant,
                                     (i & 4) ? v->codingset2 : v->codingset);
              if ((i>3) && (s->flags & CODEC_FLAG_GRAY))
                  continue;
              v->vc1dsp.vc1_inv_trans_8x8(s->block[i]);
              if (v->rangeredfrm)
                  for (j = 0; j < 64; j++)
                      s->block[i][j] <<= 1;
              s->idsp.put_signed_pixels_clamped(s->block[i],
                                                s->dest[dst_idx] + off,
                                                i & 4 ? s->uvlinesize
                                                      : s->linesize);
          } else if (val) {
              vc1_decode_p_block(v, s->block[i], i, mquant, ttmb,
                                 first_block, s->dest[dst_idx] + off,
                                 (i & 4) ? s->uvlinesize : s->linesize,
                                 (i & 4) && (s->flags & CODEC_FLAG_GRAY), NULL);
              if (!v->ttmbf && ttmb < 8)
                  ttmb = -1;
              first_block = 0;
          }
      }
  }
  
  /** Decode one B-frame MB (in interlaced field B picture)
   */
  static void vc1_decode_b_mb_intfi(VC1Context *v)
  {
      MpegEncContext *s = &v->s;
      GetBitContext *gb = &s->gb;
      int i, j;
      int mb_pos = s->mb_x + s->mb_y * s->mb_stride;
      int cbp = 0; /* cbp decoding stuff */
      int mqdiff, mquant; /* MB quantization */
      int ttmb = v->ttfrm; /* MB Transform type */
      int mb_has_coeffs = 0; /* last_flag */
      int val; /* temp value */
      int first_block = 1;
      int dst_idx, off;
      int fwd;
      int dmv_x[2], dmv_y[2], pred_flag[2];
      int bmvtype = BMV_TYPE_BACKWARD;
      int idx_mbmode;
  
      mquant      = v->pq; /* Lossy initialization */
      s->mb_intra = 0;
  
      idx_mbmode = get_vlc2(gb, v->mbmode_vlc->table, VC1_IF_MBMODE_VLC_BITS, 2);
      if (idx_mbmode <= 1) { // intra MB
          v->is_intra[s->mb_x] = 0x3f; // Set the bitfield to all 1.
          s->mb_intra          = 1;
          s->current_picture.motion_val[1][s->block_index[0]][0] = 0;
          s->current_picture.motion_val[1][s->block_index[0]][1] = 0;
          s->current_picture.mb_type[mb_pos + v->mb_off]         = MB_TYPE_INTRA;
          GET_MQUANT();
          s->current_picture.qscale_table[mb_pos] = mquant;
          /* Set DC scale - y and c use the same (not sure if necessary here) */
          s->y_dc_scale = s->y_dc_scale_table[mquant];
          s->c_dc_scale = s->c_dc_scale_table[mquant];
          v->s.ac_pred  = v->acpred_plane[mb_pos] = get_bits1(gb);
          mb_has_coeffs = idx_mbmode & 1;
          if (mb_has_coeffs)
              cbp = 1 + get_vlc2(&v->s.gb, v->cbpcy_vlc->table, VC1_ICBPCY_VLC_BITS, 2);
          dst_idx = 0;
          for (i = 0; i < 6; i++) {
              v->a_avail = v->c_avail          = 0;
              v->mb_type[0][s->block_index[i]] = 1;
              s->dc_val[0][s->block_index[i]]  = 0;
              dst_idx += i >> 2;
              val = ((cbp >> (5 - i)) & 1);
              if (i == 2 || i == 3 || !s->first_slice_line)
                  v->a_avail = v->mb_type[0][s->block_index[i] - s->block_wrap[i]];
              if (i == 1 || i == 3 || s->mb_x)
                  v->c_avail = v->mb_type[0][s->block_index[i] - 1];
  
              vc1_decode_intra_block(v, s->block[i], i, val, mquant,
                                     (i & 4) ? v->codingset2 : v->codingset);
              if ((i>3) && (s->flags & CODEC_FLAG_GRAY))
                  continue;
              v->vc1dsp.vc1_inv_trans_8x8(s->block[i]);
              if (v->rangeredfrm)
                  for (j = 0; j < 64; j++)
                      s->block[i][j] <<= 1;
              off  = (i & 4) ? 0 : ((i & 1) * 8 + (i & 2) * 4 * s->linesize);
              s->idsp.put_signed_pixels_clamped(s->block[i],
                                                s->dest[dst_idx] + off,
                                                (i & 4) ? s->uvlinesize
                                                        : s->linesize);
              // TODO: yet to perform loop filter
          }
      } else {
          s->mb_intra = v->is_intra[s->mb_x] = 0;
          s->current_picture.mb_type[mb_pos + v->mb_off] = MB_TYPE_16x16;
          for (i = 0; i < 6; i++)
              v->mb_type[0][s->block_index[i]] = 0;
          if (v->fmb_is_raw)
              fwd = v->forward_mb_plane[mb_pos] = get_bits1(gb);
          else
              fwd = v->forward_mb_plane[mb_pos];
          if (idx_mbmode <= 5) { // 1-MV
              int interpmvp = 0;
              dmv_x[0]     = dmv_x[1] = dmv_y[0] = dmv_y[1] = 0;
              pred_flag[0] = pred_flag[1] = 0;
              if (fwd)
                  bmvtype = BMV_TYPE_FORWARD;
              else {
                  bmvtype = decode012(gb);
                  switch (bmvtype) {
                  case 0:
                      bmvtype = BMV_TYPE_BACKWARD;
                      break;
                  case 1:
                      bmvtype = BMV_TYPE_DIRECT;
                      break;
                  case 2:
                      bmvtype   = BMV_TYPE_INTERPOLATED;
                      interpmvp = get_bits1(gb);
                  }
              }
              v->bmvtype = bmvtype;
              if (bmvtype != BMV_TYPE_DIRECT && idx_mbmode & 1) {
                  get_mvdata_interlaced(v, &dmv_x[bmvtype == BMV_TYPE_BACKWARD], &dmv_y[bmvtype == BMV_TYPE_BACKWARD], &pred_flag[bmvtype == BMV_TYPE_BACKWARD]);
              }
              if (interpmvp) {
                  get_mvdata_interlaced(v, &dmv_x[1], &dmv_y[1], &pred_flag[1]);
              }
              if (bmvtype == BMV_TYPE_DIRECT) {
                  dmv_x[0] = dmv_y[0] = pred_flag[0] = 0;
                  dmv_x[1] = dmv_y[1] = pred_flag[0] = 0;
                  if (!s->next_picture_ptr->field_picture) {
                      av_log(s->avctx, AV_LOG_ERROR, "Mixed field/frame direct mode not supported\n");
                      return;
                  }
              }
              ff_vc1_pred_b_mv_intfi(v, 0, dmv_x, dmv_y, 1, pred_flag);
              vc1_b_mc(v, dmv_x, dmv_y, (bmvtype == BMV_TYPE_DIRECT), bmvtype);
              mb_has_coeffs = !(idx_mbmode & 2);
          } else { // 4-MV
              if (fwd)
                  bmvtype = BMV_TYPE_FORWARD;
              v->bmvtype  = bmvtype;
              v->fourmvbp = get_vlc2(gb, v->fourmvbp_vlc->table, VC1_4MV_BLOCK_PATTERN_VLC_BITS, 1);
              for (i = 0; i < 4; i++) {
                  dmv_x[0] = dmv_y[0] = pred_flag[0] = 0;
                  dmv_x[1] = dmv_y[1] = pred_flag[1] = 0;
                  if (v->fourmvbp & (8 >> i)) {
                      get_mvdata_interlaced(v, &dmv_x[bmvtype == BMV_TYPE_BACKWARD],
                                               &dmv_y[bmvtype == BMV_TYPE_BACKWARD],
                                           &pred_flag[bmvtype == BMV_TYPE_BACKWARD]);
                  }
                  ff_vc1_pred_b_mv_intfi(v, i, dmv_x, dmv_y, 0, pred_flag);
                  ff_vc1_mc_4mv_luma(v, i, bmvtype == BMV_TYPE_BACKWARD, 0);
              }
              ff_vc1_mc_4mv_chroma(v, bmvtype == BMV_TYPE_BACKWARD);
              mb_has_coeffs = idx_mbmode & 1;
          }
          if (mb_has_coeffs)
              cbp = 1 + get_vlc2(&v->s.gb, v->cbpcy_vlc->table, VC1_CBPCY_P_VLC_BITS, 2);
          if (cbp) {
              GET_MQUANT();
          }
          s->current_picture.qscale_table[mb_pos] = mquant;
          if (!v->ttmbf && cbp) {
              ttmb = get_vlc2(gb, ff_vc1_ttmb_vlc[v->tt_index].table, VC1_TTMB_VLC_BITS, 2);
          }
          dst_idx = 0;
          for (i = 0; i < 6; i++) {
              s->dc_val[0][s->block_index[i]] = 0;
              dst_idx += i >> 2;
              val = ((cbp >> (5 - i)) & 1);
              off = (i & 4) ? 0 : (i & 1) * 8 + (i & 2) * 4 * s->linesize;
              if (val) {
                  vc1_decode_p_block(v, s->block[i], i, mquant, ttmb,
                                     first_block, s->dest[dst_idx] + off,
                                     (i & 4) ? s->uvlinesize : s->linesize,
                                     (i & 4) && (s->flags & CODEC_FLAG_GRAY), NULL);
                  if (!v->ttmbf && ttmb < 8)
                      ttmb = -1;
                  first_block = 0;
              }
          }
      }
  }
  
  /** Decode one B-frame MB (in interlaced frame B picture)
   */
  static int vc1_decode_b_mb_intfr(VC1Context *v)
  {
      MpegEncContext *s = &v->s;
      GetBitContext *gb = &s->gb;
      int i, j;
      int mb_pos = s->mb_x + s->mb_y * s->mb_stride;
      int cbp = 0; /* cbp decoding stuff */
      int mqdiff, mquant; /* MB quantization */
      int ttmb = v->ttfrm; /* MB Transform type */
      int mvsw = 0; /* motion vector switch */
      int mb_has_coeffs = 1; /* last_flag */
      int dmv_x, dmv_y; /* Differential MV components */
      int val; /* temp value */
      int first_block = 1;
      int dst_idx, off;
      int skipped, direct, twomv = 0;
      int block_cbp = 0, pat, block_tt = 0;
      int idx_mbmode = 0, mvbp;
      int stride_y, fieldtx;
      int bmvtype = BMV_TYPE_BACKWARD;
      int dir, dir2;
  
      mquant = v->pq; /* Lossy initialization */
      s->mb_intra = 0;
      if (v->skip_is_raw)
          skipped = get_bits1(gb);
      else
          skipped = v->s.mbskip_table[mb_pos];
  
      if (!skipped) {
          idx_mbmode = get_vlc2(gb, v->mbmode_vlc->table, VC1_INTFR_NON4MV_MBMODE_VLC_BITS, 2);
          if (ff_vc1_mbmode_intfrp[0][idx_mbmode][0] == MV_PMODE_INTFR_2MV_FIELD) {
              twomv = 1;
              v->blk_mv_type[s->block_index[0]] = 1;
              v->blk_mv_type[s->block_index[1]] = 1;
              v->blk_mv_type[s->block_index[2]] = 1;
              v->blk_mv_type[s->block_index[3]] = 1;
          } else {
              v->blk_mv_type[s->block_index[0]] = 0;
              v->blk_mv_type[s->block_index[1]] = 0;
              v->blk_mv_type[s->block_index[2]] = 0;
              v->blk_mv_type[s->block_index[3]] = 0;
          }
      }
  
      if (v->dmb_is_raw)
          direct = get_bits1(gb);
      else
          direct = v->direct_mb_plane[mb_pos];
  
      if (direct) {
          if (s->next_picture_ptr->field_picture)
              av_log(s->avctx, AV_LOG_WARNING, "Mixed frame/field direct mode not supported\n");
          s->mv[0][0][0] = s->current_picture.motion_val[0][s->block_index[0]][0] = scale_mv(s->next_picture.motion_val[1][s->block_index[0]][0], v->bfraction, 0, s->quarter_sample);
          s->mv[0][0][1] = s->current_picture.motion_val[0][s->block_index[0]][1] = scale_mv(s->next_picture.motion_val[1][s->block_index[0]][1], v->bfraction, 0, s->quarter_sample);
          s->mv[1][0][0] = s->current_picture.motion_val[1][s->block_index[0]][0] = scale_mv(s->next_picture.motion_val[1][s->block_index[0]][0], v->bfraction, 1, s->quarter_sample);
          s->mv[1][0][1] = s->current_picture.motion_val[1][s->block_index[0]][1] = scale_mv(s->next_picture.motion_val[1][s->block_index[0]][1], v->bfraction, 1, s->quarter_sample);
  
          if (twomv) {
              s->mv[0][2][0] = s->current_picture.motion_val[0][s->block_index[2]][0] = scale_mv(s->next_picture.motion_val[1][s->block_index[2]][0], v->bfraction, 0, s->quarter_sample);
              s->mv[0][2][1] = s->current_picture.motion_val[0][s->block_index[2]][1] = scale_mv(s->next_picture.motion_val[1][s->block_index[2]][1], v->bfraction, 0, s->quarter_sample);
              s->mv[1][2][0] = s->current_picture.motion_val[1][s->block_index[2]][0] = scale_mv(s->next_picture.motion_val[1][s->block_index[2]][0], v->bfraction, 1, s->quarter_sample);
              s->mv[1][2][1] = s->current_picture.motion_val[1][s->block_index[2]][1] = scale_mv(s->next_picture.motion_val[1][s->block_index[2]][1], v->bfraction, 1, s->quarter_sample);
  
              for (i = 1; i < 4; i += 2) {
                  s->mv[0][i][0] = s->current_picture.motion_val[0][s->block_index[i]][0] = s->mv[0][i-1][0];
                  s->mv[0][i][1] = s->current_picture.motion_val[0][s->block_index[i]][1] = s->mv[0][i-1][1];
                  s->mv[1][i][0] = s->current_picture.motion_val[1][s->block_index[i]][0] = s->mv[1][i-1][0];
                  s->mv[1][i][1] = s->current_picture.motion_val[1][s->block_index[i]][1] = s->mv[1][i-1][1];
              }
          } else {
              for (i = 1; i < 4; i++) {
                  s->mv[0][i][0] = s->current_picture.motion_val[0][s->block_index[i]][0] = s->mv[0][0][0];
                  s->mv[0][i][1] = s->current_picture.motion_val[0][s->block_index[i]][1] = s->mv[0][0][1];
                  s->mv[1][i][0] = s->current_picture.motion_val[1][s->block_index[i]][0] = s->mv[1][0][0];
                  s->mv[1][i][1] = s->current_picture.motion_val[1][s->block_index[i]][1] = s->mv[1][0][1];
              }
          }
      }
  
      if (ff_vc1_mbmode_intfrp[0][idx_mbmode][0] == MV_PMODE_INTFR_INTRA) { // intra MB
          for (i = 0; i < 4; i++) {
              s->mv[0][i][0] = s->current_picture.motion_val[0][s->block_index[i]][0] = 0;
              s->mv[0][i][1] = s->current_picture.motion_val[0][s->block_index[i]][1] = 0;
              s->mv[1][i][0] = s->current_picture.motion_val[1][s->block_index[i]][0] = 0;
              s->mv[1][i][1] = s->current_picture.motion_val[1][s->block_index[i]][1] = 0;
          }
          v->is_intra[s->mb_x] = 0x3f; // Set the bitfield to all 1.
          s->mb_intra          = 1;
          s->current_picture.mb_type[mb_pos] = MB_TYPE_INTRA;
          fieldtx = v->fieldtx_plane[mb_pos] = get_bits1(gb);
          mb_has_coeffs = get_bits1(gb);
          if (mb_has_coeffs)
              cbp = 1 + get_vlc2(&v->s.gb, v->cbpcy_vlc->table, VC1_CBPCY_P_VLC_BITS, 2);
          v->s.ac_pred = v->acpred_plane[mb_pos] = get_bits1(gb);
          GET_MQUANT();
          s->current_picture.qscale_table[mb_pos] = mquant;
          /* Set DC scale - y and c use the same (not sure if necessary here) */
          s->y_dc_scale = s->y_dc_scale_table[mquant];
          s->c_dc_scale = s->c_dc_scale_table[mquant];
          dst_idx = 0;
          for (i = 0; i < 6; i++) {
              v->a_avail = v->c_avail          = 0;
              v->mb_type[0][s->block_index[i]] = 1;
              s->dc_val[0][s->block_index[i]]  = 0;
              dst_idx += i >> 2;
              val = ((cbp >> (5 - i)) & 1);
              if (i == 2 || i == 3 || !s->first_slice_line)
                  v->a_avail = v->mb_type[0][s->block_index[i] - s->block_wrap[i]];
              if (i == 1 || i == 3 || s->mb_x)
                  v->c_avail = v->mb_type[0][s->block_index[i] - 1];
  
              vc1_decode_intra_block(v, s->block[i], i, val, mquant,
                                     (i & 4) ? v->codingset2 : v->codingset);
              if (i > 3 && (s->flags & CODEC_FLAG_GRAY))
                  continue;
              v->vc1dsp.vc1_inv_trans_8x8(s->block[i]);
              if (i < 4) {
                  stride_y = s->linesize << fieldtx;
                  off = (fieldtx) ? ((i & 1) * 8) + ((i & 2) >> 1) * s->linesize : (i & 1) * 8 + 4 * (i & 2) * s->linesize;
              } else {
                  stride_y = s->uvlinesize;
                  off = 0;
              }
              s->idsp.put_signed_pixels_clamped(s->block[i],
                                                s->dest[dst_idx] + off,
                                                stride_y);
          }
      } else {
          s->mb_intra = v->is_intra[s->mb_x] = 0;
          if (!direct) {
              if (skipped || !s->mb_intra) {
                  bmvtype = decode012(gb);
                  switch (bmvtype) {
                  case 0:
                      bmvtype = (v->bfraction >= (B_FRACTION_DEN/2)) ? BMV_TYPE_BACKWARD : BMV_TYPE_FORWARD;
                      break;
                  case 1:
                      bmvtype = (v->bfraction >= (B_FRACTION_DEN/2)) ? BMV_TYPE_FORWARD : BMV_TYPE_BACKWARD;
                      break;
                  case 2:
                      bmvtype  = BMV_TYPE_INTERPOLATED;
                  }
              }
  
              if (twomv && bmvtype != BMV_TYPE_INTERPOLATED)
                  mvsw = get_bits1(gb);
          }
  
          if (!skipped) { // inter MB
              mb_has_coeffs = ff_vc1_mbmode_intfrp[0][idx_mbmode][3];
              if (mb_has_coeffs)
                  cbp = 1 + get_vlc2(&v->s.gb, v->cbpcy_vlc->table, VC1_CBPCY_P_VLC_BITS, 2);
              if (!direct) {
                  if (bmvtype == BMV_TYPE_INTERPOLATED && twomv) {
                      v->fourmvbp = get_vlc2(gb, v->fourmvbp_vlc->table, VC1_4MV_BLOCK_PATTERN_VLC_BITS, 1);
                  } else if (bmvtype == BMV_TYPE_INTERPOLATED || twomv) {
                      v->twomvbp = get_vlc2(gb, v->twomvbp_vlc->table, VC1_2MV_BLOCK_PATTERN_VLC_BITS, 1);
                  }
              }
  
              for (i = 0; i < 6; i++)
                  v->mb_type[0][s->block_index[i]] = 0;
              fieldtx = v->fieldtx_plane[mb_pos] = ff_vc1_mbmode_intfrp[0][idx_mbmode][1];
              /* for all motion vector read MVDATA and motion compensate each block */
              dst_idx = 0;
              if (direct) {
                  if (twomv) {
                      for (i = 0; i < 4; i++) {
                          ff_vc1_mc_4mv_luma(v, i, 0, 0);
                          ff_vc1_mc_4mv_luma(v, i, 1, 1);
                      }
                      ff_vc1_mc_4mv_chroma4(v, 0, 0, 0);
                      ff_vc1_mc_4mv_chroma4(v, 1, 1, 1);
                  } else {
                      ff_vc1_mc_1mv(v, 0);
                      ff_vc1_interp_mc(v);
                  }
              } else if (twomv && bmvtype == BMV_TYPE_INTERPOLATED) {
                  mvbp = v->fourmvbp;
                  for (i = 0; i < 4; i++) {
                      dir = i==1 || i==3;
                      dmv_x = dmv_y = 0;
                      val = ((mvbp >> (3 - i)) & 1);
                      if (val)
                          get_mvdata_interlaced(v, &dmv_x, &dmv_y, 0);
                      j = i > 1 ? 2 : 0;
                      ff_vc1_pred_mv_intfr(v, j, dmv_x, dmv_y, 2, v->range_x, v->range_y, v->mb_type[0], dir);
                      ff_vc1_mc_4mv_luma(v, j, dir, dir);
                      ff_vc1_mc_4mv_luma(v, j+1, dir, dir);
                  }
  
                  ff_vc1_mc_4mv_chroma4(v, 0, 0, 0);
                  ff_vc1_mc_4mv_chroma4(v, 1, 1, 1);
              } else if (bmvtype == BMV_TYPE_INTERPOLATED) {
                  mvbp = v->twomvbp;
                  dmv_x = dmv_y = 0;
                  if (mvbp & 2)
                      get_mvdata_interlaced(v, &dmv_x, &dmv_y, 0);
  
                  ff_vc1_pred_mv_intfr(v, 0, dmv_x, dmv_y, 1, v->range_x, v->range_y, v->mb_type[0], 0);
                  ff_vc1_mc_1mv(v, 0);
  
                  dmv_x = dmv_y = 0;
                  if (mvbp & 1)
                      get_mvdata_interlaced(v, &dmv_x, &dmv_y, 0);
  
                  ff_vc1_pred_mv_intfr(v, 0, dmv_x, dmv_y, 1, v->range_x, v->range_y, v->mb_type[0], 1);
                  ff_vc1_interp_mc(v);
              } else if (twomv) {
                  dir = bmvtype == BMV_TYPE_BACKWARD;
                  dir2 = dir;
                  if (mvsw)
                      dir2 = !dir;
                  mvbp = v->twomvbp;
                  dmv_x = dmv_y = 0;
                  if (mvbp & 2)
                      get_mvdata_interlaced(v, &dmv_x, &dmv_y, 0);
                  ff_vc1_pred_mv_intfr(v, 0, dmv_x, dmv_y, 2, v->range_x, v->range_y, v->mb_type[0], dir);
  
                  dmv_x = dmv_y = 0;
                  if (mvbp & 1)
                      get_mvdata_interlaced(v, &dmv_x, &dmv_y, 0);
                  ff_vc1_pred_mv_intfr(v, 2, dmv_x, dmv_y, 2, v->range_x, v->range_y, v->mb_type[0], dir2);
  
                  if (mvsw) {
                      for (i = 0; i < 2; i++) {
                          s->mv[dir][i+2][0] = s->mv[dir][i][0] = s->current_picture.motion_val[dir][s->block_index[i+2]][0] = s->current_picture.motion_val[dir][s->block_index[i]][0];
                          s->mv[dir][i+2][1] = s->mv[dir][i][1] = s->current_picture.motion_val[dir][s->block_index[i+2]][1] = s->current_picture.motion_val[dir][s->block_index[i]][1];
                          s->mv[dir2][i+2][0] = s->mv[dir2][i][0] = s->current_picture.motion_val[dir2][s->block_index[i]][0] = s->current_picture.motion_val[dir2][s->block_index[i+2]][0];
                          s->mv[dir2][i+2][1] = s->mv[dir2][i][1] = s->current_picture.motion_val[dir2][s->block_index[i]][1] = s->current_picture.motion_val[dir2][s->block_index[i+2]][1];
                      }
                  } else {
                      ff_vc1_pred_mv_intfr(v, 0, 0, 0, 2, v->range_x, v->range_y, v->mb_type[0], !dir);
                      ff_vc1_pred_mv_intfr(v, 2, 0, 0, 2, v->range_x, v->range_y, v->mb_type[0], !dir);
                  }
  
                  ff_vc1_mc_4mv_luma(v, 0, dir, 0);
                  ff_vc1_mc_4mv_luma(v, 1, dir, 0);
                  ff_vc1_mc_4mv_luma(v, 2, dir2, 0);
                  ff_vc1_mc_4mv_luma(v, 3, dir2, 0);
                  ff_vc1_mc_4mv_chroma4(v, dir, dir2, 0);
              } else {
                  dir = bmvtype == BMV_TYPE_BACKWARD;
  
                  mvbp = ff_vc1_mbmode_intfrp[0][idx_mbmode][2];
                  dmv_x = dmv_y = 0;
                  if (mvbp)
                      get_mvdata_interlaced(v, &dmv_x, &dmv_y, 0);
  
                  ff_vc1_pred_mv_intfr(v, 0, dmv_x, dmv_y, 1, v->range_x, v->range_y, v->mb_type[0], dir);
                  v->blk_mv_type[s->block_index[0]] = 1;
                  v->blk_mv_type[s->block_index[1]] = 1;
                  v->blk_mv_type[s->block_index[2]] = 1;
                  v->blk_mv_type[s->block_index[3]] = 1;
                  ff_vc1_pred_mv_intfr(v, 0, 0, 0, 2, v->range_x, v->range_y, 0, !dir);
                  for (i = 0; i < 2; i++) {
                      s->mv[!dir][i+2][0] = s->mv[!dir][i][0] = s->current_picture.motion_val[!dir][s->block_index[i+2]][0] = s->current_picture.motion_val[!dir][s->block_index[i]][0];
                      s->mv[!dir][i+2][1] = s->mv[!dir][i][1] = s->current_picture.motion_val[!dir][s->block_index[i+2]][1] = s->current_picture.motion_val[!dir][s->block_index[i]][1];
                  }
                  ff_vc1_mc_1mv(v, dir);
              }
  
              if (cbp)
                  GET_MQUANT();  // p. 227
              s->current_picture.qscale_table[mb_pos] = mquant;
              if (!v->ttmbf && cbp)
                  ttmb = get_vlc2(gb, ff_vc1_ttmb_vlc[v->tt_index].table, VC1_TTMB_VLC_BITS, 2);
              for (i = 0; i < 6; i++) {
                  s->dc_val[0][s->block_index[i]] = 0;
                  dst_idx += i >> 2;
                  val = ((cbp >> (5 - i)) & 1);
                  if (!fieldtx)
                      off = (i & 4) ? 0 : ((i & 1) * 8 + (i & 2) * 4 * s->linesize);
                  else
                      off = (i & 4) ? 0 : ((i & 1) * 8 + ((i > 1) * s->linesize));
                  if (val) {
                      pat = vc1_decode_p_block(v, s->block[i], i, mquant, ttmb,
                                               first_block, s->dest[dst_idx] + off,
                                               (i & 4) ? s->uvlinesize : (s->linesize << fieldtx),
                                               (i & 4) && (s->flags & CODEC_FLAG_GRAY), &block_tt);
                      block_cbp |= pat << (i << 2);
                      if (!v->ttmbf && ttmb < 8)
                          ttmb = -1;
                      first_block = 0;
                  }
              }
  
          } else { // skipped
              dir = 0;
              for (i = 0; i < 6; i++) {
                  v->mb_type[0][s->block_index[i]] = 0;
                  s->dc_val[0][s->block_index[i]] = 0;
              }
              s->current_picture.mb_type[mb_pos]      = MB_TYPE_SKIP;
              s->current_picture.qscale_table[mb_pos] = 0;
              v->blk_mv_type[s->block_index[0]] = 0;
              v->blk_mv_type[s->block_index[1]] = 0;
              v->blk_mv_type[s->block_index[2]] = 0;
              v->blk_mv_type[s->block_index[3]] = 0;
  
              if (!direct) {
                  if (bmvtype == BMV_TYPE_INTERPOLATED) {
                      ff_vc1_pred_mv_intfr(v, 0, 0, 0, 1, v->range_x, v->range_y, v->mb_type[0], 0);
                      ff_vc1_pred_mv_intfr(v, 0, 0, 0, 1, v->range_x, v->range_y, v->mb_type[0], 1);
                  } else {
                      dir = bmvtype == BMV_TYPE_BACKWARD;
                      ff_vc1_pred_mv_intfr(v, 0, 0, 0, 1, v->range_x, v->range_y, v->mb_type[0], dir);
                      if (mvsw) {
                          int dir2 = dir;
                          if (mvsw)
                              dir2 = !dir;
                          for (i = 0; i < 2; i++) {
                              s->mv[dir][i+2][0] = s->mv[dir][i][0] = s->current_picture.motion_val[dir][s->block_index[i+2]][0] = s->current_picture.motion_val[dir][s->block_index[i]][0];
                              s->mv[dir][i+2][1] = s->mv[dir][i][1] = s->current_picture.motion_val[dir][s->block_index[i+2]][1] = s->current_picture.motion_val[dir][s->block_index[i]][1];
                              s->mv[dir2][i+2][0] = s->mv[dir2][i][0] = s->current_picture.motion_val[dir2][s->block_index[i]][0] = s->current_picture.motion_val[dir2][s->block_index[i+2]][0];
                              s->mv[dir2][i+2][1] = s->mv[dir2][i][1] = s->current_picture.motion_val[dir2][s->block_index[i]][1] = s->current_picture.motion_val[dir2][s->block_index[i+2]][1];
                          }
                      } else {
                          v->blk_mv_type[s->block_index[0]] = 1;
                          v->blk_mv_type[s->block_index[1]] = 1;
                          v->blk_mv_type[s->block_index[2]] = 1;
                          v->blk_mv_type[s->block_index[3]] = 1;
                          ff_vc1_pred_mv_intfr(v, 0, 0, 0, 2, v->range_x, v->range_y, 0, !dir);
                          for (i = 0; i < 2; i++) {
                              s->mv[!dir][i+2][0] = s->mv[!dir][i][0] = s->current_picture.motion_val[!dir][s->block_index[i+2]][0] = s->current_picture.motion_val[!dir][s->block_index[i]][0];
                              s->mv[!dir][i+2][1] = s->mv[!dir][i][1] = s->current_picture.motion_val[!dir][s->block_index[i+2]][1] = s->current_picture.motion_val[!dir][s->block_index[i]][1];
                          }
                      }
                  }
              }
  
              ff_vc1_mc_1mv(v, dir);
              if (direct || bmvtype == BMV_TYPE_INTERPOLATED) {
                  ff_vc1_interp_mc(v);
              }
          }
      }
      if (s->mb_x == s->mb_width - 1)
          memmove(v->is_intra_base, v->is_intra, sizeof(v->is_intra_base[0]) * s->mb_stride);
      v->cbp[s->mb_x]      = block_cbp;
      v->ttblk[s->mb_x]    = block_tt;
      return 0;
  }
  
  /** Decode blocks of I-frame
   */
  static void vc1_decode_i_blocks(VC1Context *v)
  {
      int k, j;
      MpegEncContext *s = &v->s;
      int cbp, val;
      uint8_t *coded_val;
      int mb_pos;
  
      /* select codingmode used for VLC tables selection */
      switch (v->y_ac_table_index) {
      case 0:
          v->codingset = (v->pqindex <= 8) ? CS_HIGH_RATE_INTRA : CS_LOW_MOT_INTRA;
          break;
      case 1:
          v->codingset = CS_HIGH_MOT_INTRA;
          break;
      case 2:
          v->codingset = CS_MID_RATE_INTRA;
          break;
      }
  
      switch (v->c_ac_table_index) {
      case 0:
          v->codingset2 = (v->pqindex <= 8) ? CS_HIGH_RATE_INTER : CS_LOW_MOT_INTER;
          break;
      case 1:
          v->codingset2 = CS_HIGH_MOT_INTER;
          break;
      case 2:
          v->codingset2 = CS_MID_RATE_INTER;
          break;
      }
  
      /* Set DC scale - y and c use the same */
      s->y_dc_scale = s->y_dc_scale_table[v->pq];
      s->c_dc_scale = s->c_dc_scale_table[v->pq];
  
      //do frame decode
      s->mb_x = s->mb_y = 0;
      s->mb_intra         = 1;
      s->first_slice_line = 1;
      for (s->mb_y = 0; s->mb_y < s->end_mb_y; s->mb_y++) {
          s->mb_x = 0;
          init_block_index(v);
          for (; s->mb_x < v->end_mb_x; s->mb_x++) {
              uint8_t *dst[6];
              ff_update_block_index(s);
              dst[0] = s->dest[0];
              dst[1] = dst[0] + 8;
              dst[2] = s->dest[0] + s->linesize * 8;
              dst[3] = dst[2] + 8;
              dst[4] = s->dest[1];
              dst[5] = s->dest[2];
              s->bdsp.clear_blocks(s->block[0]);
              mb_pos = s->mb_x + s->mb_y * s->mb_width;
              s->current_picture.mb_type[mb_pos]                     = MB_TYPE_INTRA;
              s->current_picture.qscale_table[mb_pos]                = v->pq;
              s->current_picture.motion_val[1][s->block_index[0]][0] = 0;
              s->current_picture.motion_val[1][s->block_index[0]][1] = 0;
  
              // do actual MB decoding and displaying
              cbp = get_vlc2(&v->s.gb, ff_msmp4_mb_i_vlc.table, MB_INTRA_VLC_BITS, 2);
              v->s.ac_pred = get_bits1(&v->s.gb);
  
              for (k = 0; k < 6; k++) {
                  val = ((cbp >> (5 - k)) & 1);
  
                  if (k < 4) {
                      int pred   = vc1_coded_block_pred(&v->s, k, &coded_val);
                      val        = val ^ pred;
                      *coded_val = val;
                  }
                  cbp |= val << (5 - k);
  
                  vc1_decode_i_block(v, s->block[k], k, val, (k < 4) ? v->codingset : v->codingset2);
  
                  if (k > 3 && (s->flags & CODEC_FLAG_GRAY))
                      continue;
                  v->vc1dsp.vc1_inv_trans_8x8(s->block[k]);
                  if (v->pq >= 9 && v->overlap) {
                      if (v->rangeredfrm)
                          for (j = 0; j < 64; j++)
                              s->block[k][j] <<= 1;
                      s->idsp.put_signed_pixels_clamped(s->block[k], dst[k],
                                                        k & 4 ? s->uvlinesize
                                                              : s->linesize);
                  } else {
                      if (v->rangeredfrm)
                          for (j = 0; j < 64; j++)
                              s->block[k][j] = (s->block[k][j] - 64) << 1;
                      s->idsp.put_pixels_clamped(s->block[k], dst[k],
                                                 k & 4 ? s->uvlinesize
                                                       : s->linesize);
                  }
              }
  
              if (v->pq >= 9 && v->overlap) {
                  if (s->mb_x) {
                      v->vc1dsp.vc1_h_overlap(s->dest[0], s->linesize);
                      v->vc1dsp.vc1_h_overlap(s->dest[0] + 8 * s->linesize, s->linesize);
                      if (!(s->flags & CODEC_FLAG_GRAY)) {
                          v->vc1dsp.vc1_h_overlap(s->dest[1], s->uvlinesize);
                          v->vc1dsp.vc1_h_overlap(s->dest[2], s->uvlinesize);
                      }
                  }
                  v->vc1dsp.vc1_h_overlap(s->dest[0] + 8, s->linesize);
                  v->vc1dsp.vc1_h_overlap(s->dest[0] + 8 * s->linesize + 8, s->linesize);
                  if (!s->first_slice_line) {
                      v->vc1dsp.vc1_v_overlap(s->dest[0], s->linesize);
                      v->vc1dsp.vc1_v_overlap(s->dest[0] + 8, s->linesize);
                      if (!(s->flags & CODEC_FLAG_GRAY)) {
                          v->vc1dsp.vc1_v_overlap(s->dest[1], s->uvlinesize);
                          v->vc1dsp.vc1_v_overlap(s->dest[2], s->uvlinesize);
                      }
                  }
                  v->vc1dsp.vc1_v_overlap(s->dest[0] + 8 * s->linesize, s->linesize);
                  v->vc1dsp.vc1_v_overlap(s->dest[0] + 8 * s->linesize + 8, s->linesize);
              }
              if (v->s.loop_filter)
                  ff_vc1_loop_filter_iblk(v, v->pq);
  
              if (get_bits_count(&s->gb) > v->bits) {
                  ff_er_add_slice(&s->er, 0, 0, s->mb_x, s->mb_y, ER_MB_ERROR);
                  av_log(s->avctx, AV_LOG_ERROR, "Bits overconsumption: %i > %i\n",
                         get_bits_count(&s->gb), v->bits);
                  return;
              }
          }
          if (!v->s.loop_filter)
              ff_mpeg_draw_horiz_band(s, s->mb_y * 16, 16);
          else if (s->mb_y)
              ff_mpeg_draw_horiz_band(s, (s->mb_y - 1) * 16, 16);
  
          s->first_slice_line = 0;
      }
      if (v->s.loop_filter)
          ff_mpeg_draw_horiz_band(s, (s->end_mb_y - 1) * 16, 16);
  
      /* This is intentionally mb_height and not end_mb_y - unlike in advanced
       * profile, these only differ are when decoding MSS2 rectangles. */
      ff_er_add_slice(&s->er, 0, 0, s->mb_width - 1, s->mb_height - 1, ER_MB_END);
  }
  
  /** Decode blocks of I-frame for advanced profile
   */
  static void vc1_decode_i_blocks_adv(VC1Context *v)
  {
      int k;
      MpegEncContext *s = &v->s;
      int cbp, val;
      uint8_t *coded_val;
      int mb_pos;
      int mquant = v->pq;
      int mqdiff;
      GetBitContext *gb = &s->gb;
  
      /* select codingmode used for VLC tables selection */
      switch (v->y_ac_table_index) {
      case 0:
          v->codingset = (v->pqindex <= 8) ? CS_HIGH_RATE_INTRA : CS_LOW_MOT_INTRA;
          break;
      case 1:
          v->codingset = CS_HIGH_MOT_INTRA;
          break;
      case 2:
          v->codingset = CS_MID_RATE_INTRA;
          break;
      }
  
      switch (v->c_ac_table_index) {
      case 0:
          v->codingset2 = (v->pqindex <= 8) ? CS_HIGH_RATE_INTER : CS_LOW_MOT_INTER;
          break;
      case 1:
          v->codingset2 = CS_HIGH_MOT_INTER;
          break;
      case 2:
          v->codingset2 = CS_MID_RATE_INTER;
          break;
      }
  
      // do frame decode
      s->mb_x             = s->mb_y = 0;
      s->mb_intra         = 1;
      s->first_slice_line = 1;
      s->mb_y             = s->start_mb_y;
      if (s->start_mb_y) {
          s->mb_x = 0;
          init_block_index(v);
          memset(&s->coded_block[s->block_index[0] - s->b8_stride], 0,
                 (1 + s->b8_stride) * sizeof(*s->coded_block));
      }
      for (; s->mb_y < s->end_mb_y; s->mb_y++) {
          s->mb_x = 0;
          init_block_index(v);
          for (;s->mb_x < s->mb_width; s->mb_x++) {
              int16_t (*block)[64] = v->block[v->cur_blk_idx];
              ff_update_block_index(s);
              s->bdsp.clear_blocks(block[0]);
              mb_pos = s->mb_x + s->mb_y * s->mb_stride;
              s->current_picture.mb_type[mb_pos + v->mb_off]                         = MB_TYPE_INTRA;
              s->current_picture.motion_val[1][s->block_index[0] + v->blocks_off][0] = 0;
              s->current_picture.motion_val[1][s->block_index[0] + v->blocks_off][1] = 0;
  
              // do actual MB decoding and displaying
              if (v->fieldtx_is_raw)
                  v->fieldtx_plane[mb_pos] = get_bits1(&v->s.gb);
              cbp = get_vlc2(&v->s.gb, ff_msmp4_mb_i_vlc.table, MB_INTRA_VLC_BITS, 2);
              if ( v->acpred_is_raw)
                  v->s.ac_pred = get_bits1(&v->s.gb);
              else
                  v->s.ac_pred = v->acpred_plane[mb_pos];
  
              if (v->condover == CONDOVER_SELECT && v->overflg_is_raw)
                  v->over_flags_plane[mb_pos] = get_bits1(&v->s.gb);
  
              GET_MQUANT();
  
              s->current_picture.qscale_table[mb_pos] = mquant;
              /* Set DC scale - y and c use the same */
              s->y_dc_scale = s->y_dc_scale_table[mquant];
              s->c_dc_scale = s->c_dc_scale_table[mquant];
  
              for (k = 0; k < 6; k++) {
                  val = ((cbp >> (5 - k)) & 1);
  
                  if (k < 4) {
                      int pred   = vc1_coded_block_pred(&v->s, k, &coded_val);
                      val        = val ^ pred;
                      *coded_val = val;
                  }
                  cbp |= val << (5 - k);
  
                  v->a_avail = !s->first_slice_line || (k == 2 || k == 3);
                  v->c_avail = !!s->mb_x || (k == 1 || k == 3);
  
                  vc1_decode_i_block_adv(v, block[k], k, val,
                                         (k < 4) ? v->codingset : v->codingset2, mquant);
  
                  if (k > 3 && (s->flags & CODEC_FLAG_GRAY))
                      continue;
                  v->vc1dsp.vc1_inv_trans_8x8(block[k]);
              }
  
              ff_vc1_smooth_overlap_filter_iblk(v);
              vc1_put_signed_blocks_clamped(v);
              if (v->s.loop_filter)
                  ff_vc1_loop_filter_iblk_delayed(v, v->pq);
  
              if (get_bits_count(&s->gb) > v->bits) {
                  // TODO: may need modification to handle slice coding
                  ff_er_add_slice(&s->er, 0, s->start_mb_y, s->mb_x, s->mb_y, ER_MB_ERROR);
                  av_log(s->avctx, AV_LOG_ERROR, "Bits overconsumption: %i > %i\n",
                         get_bits_count(&s->gb), v->bits);
                  return;
              }
          }
          if (!v->s.loop_filter)
              ff_mpeg_draw_horiz_band(s, s->mb_y * 16, 16);
          else if (s->mb_y)
              ff_mpeg_draw_horiz_band(s, (s->mb_y-1) * 16, 16);
          s->first_slice_line = 0;
      }
  
      /* raw bottom MB row */
      s->mb_x = 0;
      init_block_index(v);
      for (; s->mb_x < s->mb_width; s->mb_x++) {
          ff_update_block_index(s);
          vc1_put_signed_blocks_clamped(v);
          if (v->s.loop_filter)
              ff_vc1_loop_filter_iblk_delayed(v, v->pq);
      }
      if (v->s.loop_filter)
          ff_mpeg_draw_horiz_band(s, (s->end_mb_y - 1) * 16, 16);
      ff_er_add_slice(&s->er, 0, s->start_mb_y << v->field_mode, s->mb_width - 1,
                      (s->end_mb_y << v->field_mode) - 1, ER_MB_END);
  }
  
  static void vc1_decode_p_blocks(VC1Context *v)
  {
      MpegEncContext *s = &v->s;
      int apply_loop_filter;
  
      /* select codingmode used for VLC tables selection */
      switch (v->c_ac_table_index) {
      case 0:
          v->codingset = (v->pqindex <= 8) ? CS_HIGH_RATE_INTRA : CS_LOW_MOT_INTRA;
          break;
      case 1:
          v->codingset = CS_HIGH_MOT_INTRA;
          break;
      case 2:
          v->codingset = CS_MID_RATE_INTRA;
          break;
      }
  
      switch (v->c_ac_table_index) {
      case 0:
          v->codingset2 = (v->pqindex <= 8) ? CS_HIGH_RATE_INTER : CS_LOW_MOT_INTER;
          break;
      case 1:
          v->codingset2 = CS_HIGH_MOT_INTER;
          break;
      case 2:
          v->codingset2 = CS_MID_RATE_INTER;
          break;
      }
  
      apply_loop_filter   = s->loop_filter && !(s->avctx->skip_loop_filter >= AVDISCARD_NONKEY) &&
                            v->fcm == PROGRESSIVE;
      s->first_slice_line = 1;
      memset(v->cbp_base, 0, sizeof(v->cbp_base[0])*2*s->mb_stride);
      for (s->mb_y = s->start_mb_y; s->mb_y < s->end_mb_y; s->mb_y++) {
          s->mb_x = 0;
          init_block_index(v);
          for (; s->mb_x < s->mb_width; s->mb_x++) {
              ff_update_block_index(s);
  
              if (v->fcm == ILACE_FIELD)
                  vc1_decode_p_mb_intfi(v);
              else if (v->fcm == ILACE_FRAME)
                  vc1_decode_p_mb_intfr(v);
              else vc1_decode_p_mb(v);
              if (s->mb_y != s->start_mb_y && apply_loop_filter)
                  ff_vc1_apply_p_loop_filter(v);
              if (get_bits_count(&s->gb) > v->bits || get_bits_count(&s->gb) < 0) {
                  // TODO: may need modification to handle slice coding
                  ff_er_add_slice(&s->er, 0, s->start_mb_y, s->mb_x, s->mb_y, ER_MB_ERROR);
                  av_log(s->avctx, AV_LOG_ERROR, "Bits overconsumption: %i > %i at %ix%i\n",
                         get_bits_count(&s->gb), v->bits, s->mb_x, s->mb_y);
                  return;
              }
          }
          memmove(v->cbp_base,      v->cbp,      sizeof(v->cbp_base[0])      * s->mb_stride);
          memmove(v->ttblk_base,    v->ttblk,    sizeof(v->ttblk_base[0])    * s->mb_stride);
          memmove(v->is_intra_base, v->is_intra, sizeof(v->is_intra_base[0]) * s->mb_stride);
          memmove(v->luma_mv_base,  v->luma_mv,  sizeof(v->luma_mv_base[0])  * s->mb_stride);
          if (s->mb_y != s->start_mb_y)
              ff_mpeg_draw_horiz_band(s, (s->mb_y - 1) * 16, 16);
          s->first_slice_line = 0;
      }
      if (apply_loop_filter) {
          s->mb_x = 0;
          init_block_index(v);
          for (; s->mb_x < s->mb_width; s->mb_x++) {
              ff_update_block_index(s);
              ff_vc1_apply_p_loop_filter(v);
          }
      }
      if (s->end_mb_y >= s->start_mb_y)
          ff_mpeg_draw_horiz_band(s, (s->end_mb_y - 1) * 16, 16);
      ff_er_add_slice(&s->er, 0, s->start_mb_y << v->field_mode, s->mb_width - 1,
                      (s->end_mb_y << v->field_mode) - 1, ER_MB_END);
  }
  
  static void vc1_decode_b_blocks(VC1Context *v)
  {
      MpegEncContext *s = &v->s;
  
      /* select codingmode used for VLC tables selection */
      switch (v->c_ac_table_index) {
      case 0:
          v->codingset = (v->pqindex <= 8) ? CS_HIGH_RATE_INTRA : CS_LOW_MOT_INTRA;
          break;
      case 1:
          v->codingset = CS_HIGH_MOT_INTRA;
          break;
      case 2:
          v->codingset = CS_MID_RATE_INTRA;
          break;
      }
  
      switch (v->c_ac_table_index) {
      case 0:
          v->codingset2 = (v->pqindex <= 8) ? CS_HIGH_RATE_INTER : CS_LOW_MOT_INTER;
          break;
      case 1:
          v->codingset2 = CS_HIGH_MOT_INTER;
          break;
      case 2:
          v->codingset2 = CS_MID_RATE_INTER;
          break;
      }
  
      s->first_slice_line = 1;
      for (s->mb_y = s->start_mb_y; s->mb_y < s->end_mb_y; s->mb_y++) {
          s->mb_x = 0;
          init_block_index(v);
          for (; s->mb_x < s->mb_width; s->mb_x++) {
              ff_update_block_index(s);
  
              if (v->fcm == ILACE_FIELD)
                  vc1_decode_b_mb_intfi(v);
              else if (v->fcm == ILACE_FRAME)
                  vc1_decode_b_mb_intfr(v);
              else
                  vc1_decode_b_mb(v);
              if (get_bits_count(&s->gb) > v->bits || get_bits_count(&s->gb) < 0) {
                  // TODO: may need modification to handle slice coding
                  ff_er_add_slice(&s->er, 0, s->start_mb_y, s->mb_x, s->mb_y, ER_MB_ERROR);
                  av_log(s->avctx, AV_LOG_ERROR, "Bits overconsumption: %i > %i at %ix%i\n",
                         get_bits_count(&s->gb), v->bits, s->mb_x, s->mb_y);
                  return;
              }
              if (v->s.loop_filter)
                  ff_vc1_loop_filter_iblk(v, v->pq);
          }
          if (!v->s.loop_filter)
              ff_mpeg_draw_horiz_band(s, s->mb_y * 16, 16);
          else if (s->mb_y)
              ff_mpeg_draw_horiz_band(s, (s->mb_y - 1) * 16, 16);
          s->first_slice_line = 0;
      }
      if (v->s.loop_filter)
          ff_mpeg_draw_horiz_band(s, (s->end_mb_y - 1) * 16, 16);
      ff_er_add_slice(&s->er, 0, s->start_mb_y << v->field_mode, s->mb_width - 1,
                      (s->end_mb_y << v->field_mode) - 1, ER_MB_END);
  }
  
  static void vc1_decode_skip_blocks(VC1Context *v)
  {
      MpegEncContext *s = &v->s;
  
      if (!v->s.last_picture.f->data[0])
          return;
  
      ff_er_add_slice(&s->er, 0, s->start_mb_y, s->mb_width - 1, s->end_mb_y - 1, ER_MB_END);
      s->first_slice_line = 1;
      for (s->mb_y = s->start_mb_y; s->mb_y < s->end_mb_y; s->mb_y++) {
          s->mb_x = 0;
          init_block_index(v);
          ff_update_block_index(s);
          memcpy(s->dest[0], s->last_picture.f->data[0] + s->mb_y * 16 * s->linesize,   s->linesize   * 16);
          memcpy(s->dest[1], s->last_picture.f->data[1] + s->mb_y *  8 * s->uvlinesize, s->uvlinesize *  8);
          memcpy(s->dest[2], s->last_picture.f->data[2] + s->mb_y *  8 * s->uvlinesize, s->uvlinesize *  8);
          ff_mpeg_draw_horiz_band(s, s->mb_y * 16, 16);
          s->first_slice_line = 0;
      }
      s->pict_type = AV_PICTURE_TYPE_P;
  }
  
  void ff_vc1_decode_blocks(VC1Context *v)
  {
  
      v->s.esc3_level_length = 0;
      if (v->x8_type) {
          ff_intrax8_decode_picture(&v->x8, 2*v->pq + v->halfpq, v->pq * !v->pquantizer);
      } else {
          v->cur_blk_idx     =  0;
          v->left_blk_idx    = -1;
          v->topleft_blk_idx =  1;
          v->top_blk_idx     =  2;
          switch (v->s.pict_type) {
          case AV_PICTURE_TYPE_I:
              if (v->profile == PROFILE_ADVANCED)
                  vc1_decode_i_blocks_adv(v);
              else
                  vc1_decode_i_blocks(v);
              break;
          case AV_PICTURE_TYPE_P:
              if (v->p_frame_skipped)
                  vc1_decode_skip_blocks(v);
              else
                  vc1_decode_p_blocks(v);
              break;
          case AV_PICTURE_TYPE_B:
              if (v->bi_type) {
                  if (v->profile == PROFILE_ADVANCED)
                      vc1_decode_i_blocks_adv(v);
                  else
                      vc1_decode_i_blocks(v);
              } else
                  vc1_decode_b_blocks(v);
              break;
          }
      }
  }
  