text: ﻿/*
   * Copyright (C) 2003-2004 the ffmpeg project
   *
   * 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
   * On2 VP3 Video Decoder
   *
   * VP3 Video Decoder by Mike Melanson (mike at multimedia.cx)
   * For more information about the VP3 coding process, visit:
   *   http://wiki.multimedia.cx/index.php?title=On2_VP3
   *
   * Theora decoder by Alex Beregszaszi
   */
  
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  
  #include "libavutil/imgutils.h"
  #include "avcodec.h"
  #include "internal.h"
  #include "dsputil.h"
  #include "get_bits.h"
  
  #include "vp3data.h"
  #include "xiph.h"
  #include "thread.h"
  
  #define FRAGMENT_PIXELS 8
  
  static av_cold int vp3_decode_end(AVCodecContext *avctx);
  static void vp3_decode_flush(AVCodecContext *avctx);
  
  //FIXME split things out into their own arrays
  typedef struct Vp3Fragment {
      int16_t dc;
      uint8_t coding_method;
      uint8_t qpi;
  } Vp3Fragment;
  
  #define SB_NOT_CODED        0
  #define SB_PARTIALLY_CODED  1
  #define SB_FULLY_CODED      2
  
  // This is the maximum length of a single long bit run that can be encoded
  // for superblock coding or block qps. Theora special-cases this to read a
  // bit instead of flipping the current bit to allow for runs longer than 4129.
  #define MAXIMUM_LONG_BIT_RUN 4129
  
  #define MODE_INTER_NO_MV      0
  #define MODE_INTRA            1
  #define MODE_INTER_PLUS_MV    2
  #define MODE_INTER_LAST_MV    3
  #define MODE_INTER_PRIOR_LAST 4
  #define MODE_USING_GOLDEN     5
  #define MODE_GOLDEN_MV        6
  #define MODE_INTER_FOURMV     7
  #define CODING_MODE_COUNT     8
  
  /* special internal mode */
  #define MODE_COPY             8
  
  /* There are 6 preset schemes, plus a free-form scheme */
  static const int ModeAlphabet[6][CODING_MODE_COUNT] =
  {
      /* scheme 1: Last motion vector dominates */
      {    MODE_INTER_LAST_MV,    MODE_INTER_PRIOR_LAST,
           MODE_INTER_PLUS_MV,    MODE_INTER_NO_MV,
           MODE_INTRA,            MODE_USING_GOLDEN,
           MODE_GOLDEN_MV,        MODE_INTER_FOURMV },
  
      /* scheme 2 */
      {    MODE_INTER_LAST_MV,    MODE_INTER_PRIOR_LAST,
           MODE_INTER_NO_MV,      MODE_INTER_PLUS_MV,
           MODE_INTRA,            MODE_USING_GOLDEN,
           MODE_GOLDEN_MV,        MODE_INTER_FOURMV },
  
      /* scheme 3 */
      {    MODE_INTER_LAST_MV,    MODE_INTER_PLUS_MV,
           MODE_INTER_PRIOR_LAST, MODE_INTER_NO_MV,
           MODE_INTRA,            MODE_USING_GOLDEN,
           MODE_GOLDEN_MV,        MODE_INTER_FOURMV },
  
      /* scheme 4 */
      {    MODE_INTER_LAST_MV,    MODE_INTER_PLUS_MV,
           MODE_INTER_NO_MV,      MODE_INTER_PRIOR_LAST,
           MODE_INTRA,            MODE_USING_GOLDEN,
           MODE_GOLDEN_MV,        MODE_INTER_FOURMV },
  
      /* scheme 5: No motion vector dominates */
      {    MODE_INTER_NO_MV,      MODE_INTER_LAST_MV,
           MODE_INTER_PRIOR_LAST, MODE_INTER_PLUS_MV,
           MODE_INTRA,            MODE_USING_GOLDEN,
           MODE_GOLDEN_MV,        MODE_INTER_FOURMV },
  
      /* scheme 6 */
      {    MODE_INTER_NO_MV,      MODE_USING_GOLDEN,
           MODE_INTER_LAST_MV,    MODE_INTER_PRIOR_LAST,
           MODE_INTER_PLUS_MV,    MODE_INTRA,
           MODE_GOLDEN_MV,        MODE_INTER_FOURMV },
  
  };
  
  static const uint8_t hilbert_offset[16][2] = {
      {0,0}, {1,0}, {1,1}, {0,1},
      {0,2}, {0,3}, {1,3}, {1,2},
      {2,2}, {2,3}, {3,3}, {3,2},
      {3,1}, {2,1}, {2,0}, {3,0}
  };
  
  #define MIN_DEQUANT_VAL 2
  
  typedef struct Vp3DecodeContext {
      AVCodecContext *avctx;
      int theora, theora_tables;
      int version;
      int width, height;
      int chroma_x_shift, chroma_y_shift;
      AVFrame golden_frame;
      AVFrame last_frame;
      AVFrame current_frame;
      int keyframe;
      DSPContext dsp;
      int flipped_image;
      int last_slice_end;
      int skip_loop_filter;
  
      int qps[3];
      int nqps;
      int last_qps[3];
  
      int superblock_count;
      int y_superblock_width;
      int y_superblock_height;
      int y_superblock_count;
      int c_superblock_width;
      int c_superblock_height;
      int c_superblock_count;
      int u_superblock_start;
      int v_superblock_start;
      unsigned char *superblock_coding;
  
      int macroblock_count;
      int macroblock_width;
      int macroblock_height;
  
      int fragment_count;
      int fragment_width[2];
      int fragment_height[2];
  
      Vp3Fragment *all_fragments;
      int fragment_start[3];
      int data_offset[3];
  
      int8_t (*motion_val[2])[2];
  
      ScanTable scantable;
  
      /* tables */
      uint16_t coded_dc_scale_factor[64];
      uint32_t coded_ac_scale_factor[64];
      uint8_t base_matrix[384][64];
      uint8_t qr_count[2][3];
      uint8_t qr_size [2][3][64];
      uint16_t qr_base[2][3][64];
  
      /**
       * This is a list of all tokens in bitstream order. Reordering takes place
       * by pulling from each level during IDCT. As a consequence, IDCT must be
       * in Hilbert order, making the minimum slice height 64 for 4:2:0 and 32
       * otherwise. The 32 different tokens with up to 12 bits of extradata are
       * collapsed into 3 types, packed as follows:
       *   (from the low to high bits)
       *
       * 2 bits: type (0,1,2)
       *   0: EOB run, 14 bits for run length (12 needed)
       *   1: zero run, 7 bits for run length
       *                7 bits for the next coefficient (3 needed)
       *   2: coefficient, 14 bits (11 needed)
       *
       * Coefficients are signed, so are packed in the highest bits for automatic
       * sign extension.
       */
      int16_t *dct_tokens[3][64];
      int16_t *dct_tokens_base;
  #define TOKEN_EOB(eob_run)              ((eob_run) << 2)
  #define TOKEN_ZERO_RUN(coeff, zero_run) (((coeff) << 9) + ((zero_run) << 2) + 1)
  #define TOKEN_COEFF(coeff)              (((coeff) << 2) + 2)
  
      /**
       * number of blocks that contain DCT coefficients at the given level or higher
       */
      int num_coded_frags[3][64];
      int total_num_coded_frags;
  
      /* this is a list of indexes into the all_fragments array indicating
       * which of the fragments are coded */
      int *coded_fragment_list[3];
  
      VLC dc_vlc[16];
      VLC ac_vlc_1[16];
      VLC ac_vlc_2[16];
      VLC ac_vlc_3[16];
      VLC ac_vlc_4[16];
  
      VLC superblock_run_length_vlc;
      VLC fragment_run_length_vlc;
      VLC mode_code_vlc;
      VLC motion_vector_vlc;
  
      /* these arrays need to be on 16-byte boundaries since SSE2 operations
       * index into them */
      DECLARE_ALIGNED(16, int16_t, qmat)[3][2][3][64];     ///< qmat[qpi][is_inter][plane]
  
      /* This table contains superblock_count * 16 entries. Each set of 16
       * numbers corresponds to the fragment indexes 0..15 of the superblock.
       * An entry will be -1 to indicate that no entry corresponds to that
       * index. */
      int *superblock_fragments;
  
      /* This is an array that indicates how a particular macroblock
       * is coded. */
      unsigned char *macroblock_coding;
  
      uint8_t *edge_emu_buffer;
  
      /* Huffman decode */
      int hti;
      unsigned int hbits;
      int entries;
      int huff_code_size;
      uint32_t huffman_table[80][32][2];
  
      uint8_t filter_limit_values[64];
      DECLARE_ALIGNED(8, int, bounding_values_array)[256+2];
  } Vp3DecodeContext;
  
  /************************************************************************
   * VP3 specific functions
   ************************************************************************/
  
  /*
   * This function sets up all of the various blocks mappings:
   * superblocks <-> fragments, macroblocks <-> fragments,
   * superblocks <-> macroblocks
   *
   * @return 0 is successful; returns 1 if *anything* went wrong.
   */
  static int init_block_mapping(Vp3DecodeContext *s)
  {
      int sb_x, sb_y, plane;
      int x, y, i, j = 0;
  
      for (plane = 0; plane < 3; plane++) {
          int sb_width    = plane ? s->c_superblock_width  : s->y_superblock_width;
          int sb_height   = plane ? s->c_superblock_height : s->y_superblock_height;
          int frag_width  = s->fragment_width[!!plane];
          int frag_height = s->fragment_height[!!plane];
  
          for (sb_y = 0; sb_y < sb_height; sb_y++)
              for (sb_x = 0; sb_x < sb_width; sb_x++)
                  for (i = 0; i < 16; i++) {
                      x = 4*sb_x + hilbert_offset[i][0];
                      y = 4*sb_y + hilbert_offset[i][1];
  
                      if (x < frag_width && y < frag_height)
                          s->superblock_fragments[j++] = s->fragment_start[plane] + y*frag_width + x;
                      else
                          s->superblock_fragments[j++] = -1;
                  }
      }
  
      return 0;  /* successful path out */
  }
  
  /*
   * This function sets up the dequantization tables used for a particular
   * frame.
   */
  static void init_dequantizer(Vp3DecodeContext *s, int qpi)
  {
      int ac_scale_factor = s->coded_ac_scale_factor[s->qps[qpi]];
      int dc_scale_factor = s->coded_dc_scale_factor[s->qps[qpi]];
      int i, plane, inter, qri, bmi, bmj, qistart;
  
      for(inter=0; inter<2; inter++){
          for(plane=0; plane<3; plane++){
              int sum=0;
              for(qri=0; qri<s->qr_count[inter][plane]; qri++){
                  sum+= s->qr_size[inter][plane][qri];
                  if(s->qps[qpi] <= sum)
                      break;
              }
              qistart= sum - s->qr_size[inter][plane][qri];
              bmi= s->qr_base[inter][plane][qri  ];
              bmj= s->qr_base[inter][plane][qri+1];
              for(i=0; i<64; i++){
                  int coeff= (  2*(sum    -s->qps[qpi])*s->base_matrix[bmi][i]
                              - 2*(qistart-s->qps[qpi])*s->base_matrix[bmj][i]
                              + s->qr_size[inter][plane][qri])
                             / (2*s->qr_size[inter][plane][qri]);
  
                  int qmin= 8<<(inter + !i);
                  int qscale= i ? ac_scale_factor : dc_scale_factor;
  
                  s->qmat[qpi][inter][plane][s->dsp.idct_permutation[i]]= av_clip((qscale * coeff)/100 * 4, qmin, 4096);
              }
              // all DC coefficients use the same quant so as not to interfere with DC prediction
              s->qmat[qpi][inter][plane][0] = s->qmat[0][inter][plane][0];
          }
      }
  }
  
  /*
   * This function initializes the loop filter boundary limits if the frame's
   * quality index is different from the previous frame's.
   *
   * The filter_limit_values may not be larger than 127.
   */
  static void init_loop_filter(Vp3DecodeContext *s)
  {
      int *bounding_values= s->bounding_values_array+127;
      int filter_limit;
      int x;
      int value;
  
      filter_limit = s->filter_limit_values[s->qps[0]];
  
      /* set up the bounding values */
      memset(s->bounding_values_array, 0, 256 * sizeof(int));
      for (x = 0; x < filter_limit; x++) {
          bounding_values[-x] = -x;
          bounding_values[x] = x;
      }
      for (x = value = filter_limit; x < 128 && value; x++, value--) {
          bounding_values[ x] =  value;
          bounding_values[-x] = -value;
      }
      if (value)
          bounding_values[128] = value;
      bounding_values[129] = bounding_values[130] = filter_limit * 0x02020202;
  }
  
  /*
   * This function unpacks all of the superblock/macroblock/fragment coding
   * information from the bitstream.
   */
  static int unpack_superblocks(Vp3DecodeContext *s, GetBitContext *gb)
  {
      int superblock_starts[3] = { 0, s->u_superblock_start, s->v_superblock_start };
      int bit = 0;
      int current_superblock = 0;
      int current_run = 0;
      int num_partial_superblocks = 0;
  
      int i, j;
      int current_fragment;
      int plane;
  
      if (s->keyframe) {
          memset(s->superblock_coding, SB_FULLY_CODED, s->superblock_count);
  
      } else {
  
          /* unpack the list of partially-coded superblocks */
          bit = get_bits1(gb) ^ 1;
          current_run = 0;
  
          while (current_superblock < s->superblock_count && get_bits_left(gb) > 0) {
              if (s->theora && current_run == MAXIMUM_LONG_BIT_RUN)
                  bit = get_bits1(gb);
              else
                  bit ^= 1;
  
                  current_run = get_vlc2(gb,
                      s->superblock_run_length_vlc.table, 6, 2) + 1;
                  if (current_run == 34)
                      current_run += get_bits(gb, 12);
  
              if (current_superblock + current_run > s->superblock_count) {
                  av_log(s->avctx, AV_LOG_ERROR, "Invalid partially coded superblock run length\n");
                  return -1;
              }
  
              memset(s->superblock_coding + current_superblock, bit, current_run);
  
              current_superblock += current_run;
              if (bit)
                  num_partial_superblocks += current_run;
          }
  
          /* unpack the list of fully coded superblocks if any of the blocks were
           * not marked as partially coded in the previous step */
          if (num_partial_superblocks < s->superblock_count) {
              int superblocks_decoded = 0;
  
              current_superblock = 0;
              bit = get_bits1(gb) ^ 1;
              current_run = 0;
  
              while (superblocks_decoded < s->superblock_count - num_partial_superblocks
                     && get_bits_left(gb) > 0) {
  
                  if (s->theora && current_run == MAXIMUM_LONG_BIT_RUN)
                      bit = get_bits1(gb);
                  else
                      bit ^= 1;
  
                          current_run = get_vlc2(gb,
                              s->superblock_run_length_vlc.table, 6, 2) + 1;
                          if (current_run == 34)
                              current_run += get_bits(gb, 12);
  
                  for (j = 0; j < current_run; current_superblock++) {
                      if (current_superblock >= s->superblock_count) {
                          av_log(s->avctx, AV_LOG_ERROR, "Invalid fully coded superblock run length\n");
                          return -1;
                      }
  
                  /* skip any superblocks already marked as partially coded */
                  if (s->superblock_coding[current_superblock] == SB_NOT_CODED) {
                      s->superblock_coding[current_superblock] = 2*bit;
                      j++;
                  }
                  }
                  superblocks_decoded += current_run;
              }
          }
  
          /* if there were partial blocks, initialize bitstream for
           * unpacking fragment codings */
          if (num_partial_superblocks) {
  
              current_run = 0;
              bit = get_bits1(gb);
              /* toggle the bit because as soon as the first run length is
               * fetched the bit will be toggled again */
              bit ^= 1;
          }
      }
  
      /* figure out which fragments are coded; iterate through each
       * superblock (all planes) */
      s->total_num_coded_frags = 0;
      memset(s->macroblock_coding, MODE_COPY, s->macroblock_count);
  
      for (plane = 0; plane < 3; plane++) {
          int sb_start = superblock_starts[plane];
          int sb_end = sb_start + (plane ? s->c_superblock_count : s->y_superblock_count);
          int num_coded_frags = 0;
  
      for (i = sb_start; i < sb_end && get_bits_left(gb) > 0; i++) {
  
          /* iterate through all 16 fragments in a superblock */
          for (j = 0; j < 16; j++) {
  
              /* if the fragment is in bounds, check its coding status */
              current_fragment = s->superblock_fragments[i * 16 + j];
              if (current_fragment != -1) {
                  int coded = s->superblock_coding[i];
  
                  if (s->superblock_coding[i] == SB_PARTIALLY_CODED) {
  
                      /* fragment may or may not be coded; this is the case
                       * that cares about the fragment coding runs */
                      if (current_run-- == 0) {
                          bit ^= 1;
                          current_run = get_vlc2(gb,
                              s->fragment_run_length_vlc.table, 5, 2);
                      }
                      coded = bit;
                  }
  
                      if (coded) {
                          /* default mode; actual mode will be decoded in
                           * the next phase */
                          s->all_fragments[current_fragment].coding_method =
                              MODE_INTER_NO_MV;
                          s->coded_fragment_list[plane][num_coded_frags++] =
                              current_fragment;
                      } else {
                          /* not coded; copy this fragment from the prior frame */
                          s->all_fragments[current_fragment].coding_method =
                              MODE_COPY;
                      }
              }
          }
      }
          s->total_num_coded_frags += num_coded_frags;
          for (i = 0; i < 64; i++)
              s->num_coded_frags[plane][i] = num_coded_frags;
          if (plane < 2)
              s->coded_fragment_list[plane+1] = s->coded_fragment_list[plane] + num_coded_frags;
      }
      return 0;
  }
  
  /*
   * This function unpacks all the coding mode data for individual macroblocks
   * from the bitstream.
   */
  static int unpack_modes(Vp3DecodeContext *s, GetBitContext *gb)
  {
      int i, j, k, sb_x, sb_y;
      int scheme;
      int current_macroblock;
      int current_fragment;
      int coding_mode;
      int custom_mode_alphabet[CODING_MODE_COUNT];
      const int *alphabet;
      Vp3Fragment *frag;
  
      if (s->keyframe) {
          for (i = 0; i < s->fragment_count; i++)
              s->all_fragments[i].coding_method = MODE_INTRA;
  
      } else {
  
          /* fetch the mode coding scheme for this frame */
          scheme = get_bits(gb, 3);
  
          /* is it a custom coding scheme? */
          if (scheme == 0) {
              for (i = 0; i < 8; i++)
                  custom_mode_alphabet[i] = MODE_INTER_NO_MV;
              for (i = 0; i < 8; i++)
                  custom_mode_alphabet[get_bits(gb, 3)] = i;
              alphabet = custom_mode_alphabet;
          } else
              alphabet = ModeAlphabet[scheme-1];
  
          /* iterate through all of the macroblocks that contain 1 or more
           * coded fragments */
          for (sb_y = 0; sb_y < s->y_superblock_height; sb_y++) {
              for (sb_x = 0; sb_x < s->y_superblock_width; sb_x++) {
                  if (get_bits_left(gb) <= 0)
                      return -1;
  
              for (j = 0; j < 4; j++) {
                  int mb_x = 2*sb_x +   (j>>1);
                  int mb_y = 2*sb_y + (((j>>1)+j)&1);
                  current_macroblock = mb_y * s->macroblock_width + mb_x;
  
                  if (mb_x >= s->macroblock_width || mb_y >= s->macroblock_height)
                      continue;
  
  #define BLOCK_X (2*mb_x + (k&1))
  #define BLOCK_Y (2*mb_y + (k>>1))
                  /* coding modes are only stored if the macroblock has at least one
                   * luma block coded, otherwise it must be INTER_NO_MV */
                  for (k = 0; k < 4; k++) {
                      current_fragment = BLOCK_Y*s->fragment_width[0] + BLOCK_X;
                      if (s->all_fragments[current_fragment].coding_method != MODE_COPY)
                          break;
                  }
                  if (k == 4) {
                      s->macroblock_coding[current_macroblock] = MODE_INTER_NO_MV;
                      continue;
                  }
  
                  /* mode 7 means get 3 bits for each coding mode */
                  if (scheme == 7)
                      coding_mode = get_bits(gb, 3);
                  else
                      coding_mode = alphabet
                          [get_vlc2(gb, s->mode_code_vlc.table, 3, 3)];
  
                  s->macroblock_coding[current_macroblock] = coding_mode;
                  for (k = 0; k < 4; k++) {
                      frag = s->all_fragments + BLOCK_Y*s->fragment_width[0] + BLOCK_X;
                      if (frag->coding_method != MODE_COPY)
                          frag->coding_method = coding_mode;
                  }
  
  #define SET_CHROMA_MODES \
      if (frag[s->fragment_start[1]].coding_method != MODE_COPY) \
          frag[s->fragment_start[1]].coding_method = coding_mode;\
      if (frag[s->fragment_start[2]].coding_method != MODE_COPY) \
          frag[s->fragment_start[2]].coding_method = coding_mode;
  
                  if (s->chroma_y_shift) {
                      frag = s->all_fragments + mb_y*s->fragment_width[1] + mb_x;
                      SET_CHROMA_MODES
                  } else if (s->chroma_x_shift) {
                      frag = s->all_fragments + 2*mb_y*s->fragment_width[1] + mb_x;
                      for (k = 0; k < 2; k++) {
                          SET_CHROMA_MODES
                          frag += s->fragment_width[1];
                      }
                  } else {
                      for (k = 0; k < 4; k++) {
                          frag = s->all_fragments + BLOCK_Y*s->fragment_width[1] + BLOCK_X;
                          SET_CHROMA_MODES
                      }
                  }
              }
              }
          }
      }
  
      return 0;
  }
  
  /*
   * This function unpacks all the motion vectors for the individual
   * macroblocks from the bitstream.
   */
  static int unpack_vectors(Vp3DecodeContext *s, GetBitContext *gb)
  {
      int j, k, sb_x, sb_y;
      int coding_mode;
      int motion_x[4];
      int motion_y[4];
      int last_motion_x = 0;
      int last_motion_y = 0;
      int prior_last_motion_x = 0;
      int prior_last_motion_y = 0;
      int current_macroblock;
      int current_fragment;
      int frag;
  
      if (s->keyframe)
          return 0;
  
      /* coding mode 0 is the VLC scheme; 1 is the fixed code scheme */
      coding_mode = get_bits1(gb);
  
      /* iterate through all of the macroblocks that contain 1 or more
       * coded fragments */
      for (sb_y = 0; sb_y < s->y_superblock_height; sb_y++) {
          for (sb_x = 0; sb_x < s->y_superblock_width; sb_x++) {
              if (get_bits_left(gb) <= 0)
                  return -1;
  
          for (j = 0; j < 4; j++) {
              int mb_x = 2*sb_x +   (j>>1);
              int mb_y = 2*sb_y + (((j>>1)+j)&1);
              current_macroblock = mb_y * s->macroblock_width + mb_x;
  
              if (mb_x >= s->macroblock_width || mb_y >= s->macroblock_height ||
                  (s->macroblock_coding[current_macroblock] == MODE_COPY))
                  continue;
  
              switch (s->macroblock_coding[current_macroblock]) {
  
              case MODE_INTER_PLUS_MV:
              case MODE_GOLDEN_MV:
                  /* all 6 fragments use the same motion vector */
                  if (coding_mode == 0) {
                      motion_x[0] = motion_vector_table[get_vlc2(gb, s->motion_vector_vlc.table, 6, 2)];
                      motion_y[0] = motion_vector_table[get_vlc2(gb, s->motion_vector_vlc.table, 6, 2)];
                  } else {
                      motion_x[0] = fixed_motion_vector_table[get_bits(gb, 6)];
                      motion_y[0] = fixed_motion_vector_table[get_bits(gb, 6)];
                  }
  
                  /* vector maintenance, only on MODE_INTER_PLUS_MV */
                  if (s->macroblock_coding[current_macroblock] ==
                      MODE_INTER_PLUS_MV) {
                      prior_last_motion_x = last_motion_x;
                      prior_last_motion_y = last_motion_y;
                      last_motion_x = motion_x[0];
                      last_motion_y = motion_y[0];
                  }
                  break;
  
              case MODE_INTER_FOURMV:
                  /* vector maintenance */
                  prior_last_motion_x = last_motion_x;
                  prior_last_motion_y = last_motion_y;
  
                  /* fetch 4 vectors from the bitstream, one for each
                   * Y fragment, then average for the C fragment vectors */
                  for (k = 0; k < 4; k++) {
                      current_fragment = BLOCK_Y*s->fragment_width[0] + BLOCK_X;
                      if (s->all_fragments[current_fragment].coding_method != MODE_COPY) {
                          if (coding_mode == 0) {
                              motion_x[k] = motion_vector_table[get_vlc2(gb, s->motion_vector_vlc.table, 6, 2)];
                              motion_y[k] = motion_vector_table[get_vlc2(gb, s->motion_vector_vlc.table, 6, 2)];
                          } else {
                              motion_x[k] = fixed_motion_vector_table[get_bits(gb, 6)];
                              motion_y[k] = fixed_motion_vector_table[get_bits(gb, 6)];
                          }
                          last_motion_x = motion_x[k];
                          last_motion_y = motion_y[k];
                      } else {
                          motion_x[k] = 0;
                          motion_y[k] = 0;
                      }
                  }
                  break;
  
              case MODE_INTER_LAST_MV:
                  /* all 6 fragments use the last motion vector */
                  motion_x[0] = last_motion_x;
                  motion_y[0] = last_motion_y;
  
                  /* no vector maintenance (last vector remains the
                   * last vector) */
                  break;
  
              case MODE_INTER_PRIOR_LAST:
                  /* all 6 fragments use the motion vector prior to the
                   * last motion vector */
                  motion_x[0] = prior_last_motion_x;
                  motion_y[0] = prior_last_motion_y;
  
                  /* vector maintenance */
                  prior_last_motion_x = last_motion_x;
                  prior_last_motion_y = last_motion_y;
                  last_motion_x = motion_x[0];
                  last_motion_y = motion_y[0];
                  break;
  
              default:
                  /* covers intra, inter without MV, golden without MV */
                  motion_x[0] = 0;
                  motion_y[0] = 0;
  
                  /* no vector maintenance */
                  break;
              }
  
              /* assign the motion vectors to the correct fragments */
              for (k = 0; k < 4; k++) {
                  current_fragment =
                      BLOCK_Y*s->fragment_width[0] + BLOCK_X;
                  if (s->macroblock_coding[current_macroblock] == MODE_INTER_FOURMV) {
                      s->motion_val[0][current_fragment][0] = motion_x[k];
                      s->motion_val[0][current_fragment][1] = motion_y[k];
                  } else {
                      s->motion_val[0][current_fragment][0] = motion_x[0];
                      s->motion_val[0][current_fragment][1] = motion_y[0];
                  }
              }
  
              if (s->chroma_y_shift) {
                  if (s->macroblock_coding[current_macroblock] == MODE_INTER_FOURMV) {
                      motion_x[0] = RSHIFT(motion_x[0] + motion_x[1] + motion_x[2] + motion_x[3], 2);
                      motion_y[0] = RSHIFT(motion_y[0] + motion_y[1] + motion_y[2] + motion_y[3], 2);
                  }
                  motion_x[0] = (motion_x[0]>>1) | (motion_x[0]&1);
                  motion_y[0] = (motion_y[0]>>1) | (motion_y[0]&1);
                  frag = mb_y*s->fragment_width[1] + mb_x;
                  s->motion_val[1][frag][0] = motion_x[0];
                  s->motion_val[1][frag][1] = motion_y[0];
              } else if (s->chroma_x_shift) {
                  if (s->macroblock_coding[current_macroblock] == MODE_INTER_FOURMV) {
                      motion_x[0] = RSHIFT(motion_x[0] + motion_x[1], 1);
                      motion_y[0] = RSHIFT(motion_y[0] + motion_y[1], 1);
                      motion_x[1] = RSHIFT(motion_x[2] + motion_x[3], 1);
                      motion_y[1] = RSHIFT(motion_y[2] + motion_y[3], 1);
                  } else {
                      motion_x[1] = motion_x[0];
                      motion_y[1] = motion_y[0];
                  }
                  motion_x[0] = (motion_x[0]>>1) | (motion_x[0]&1);
                  motion_x[1] = (motion_x[1]>>1) | (motion_x[1]&1);
  
                  frag = 2*mb_y*s->fragment_width[1] + mb_x;
                  for (k = 0; k < 2; k++) {
                      s->motion_val[1][frag][0] = motion_x[k];
                      s->motion_val[1][frag][1] = motion_y[k];
                      frag += s->fragment_width[1];
                  }
              } else {
                  for (k = 0; k < 4; k++) {
                      frag = BLOCK_Y*s->fragment_width[1] + BLOCK_X;
                      if (s->macroblock_coding[current_macroblock] == MODE_INTER_FOURMV) {
                          s->motion_val[1][frag][0] = motion_x[k];
                          s->motion_val[1][frag][1] = motion_y[k];
                      } else {
                          s->motion_val[1][frag][0] = motion_x[0];
                          s->motion_val[1][frag][1] = motion_y[0];
                      }
                  }
              }
          }
          }
      }
  
      return 0;
  }
  
  static int unpack_block_qpis(Vp3DecodeContext *s, GetBitContext *gb)
  {
      int qpi, i, j, bit, run_length, blocks_decoded, num_blocks_at_qpi;
      int num_blocks = s->total_num_coded_frags;
  
      for (qpi = 0; qpi < s->nqps-1 && num_blocks > 0; qpi++) {
          i = blocks_decoded = num_blocks_at_qpi = 0;
  
          bit = get_bits1(gb) ^ 1;
          run_length = 0;
  
          do {
              if (run_length == MAXIMUM_LONG_BIT_RUN)
                  bit = get_bits1(gb);
              else
                  bit ^= 1;
  
              run_length = get_vlc2(gb, s->superblock_run_length_vlc.table, 6, 2) + 1;
              if (run_length == 34)
                  run_length += get_bits(gb, 12);
              blocks_decoded += run_length;
  
              if (!bit)
                  num_blocks_at_qpi += run_length;
  
              for (j = 0; j < run_length; i++) {
                  if (i >= s->total_num_coded_frags)
                      return -1;
  
                  if (s->all_fragments[s->coded_fragment_list[0][i]].qpi == qpi) {
                      s->all_fragments[s->coded_fragment_list[0][i]].qpi += bit;
                      j++;
                  }
              }
          } while (blocks_decoded < num_blocks && get_bits_left(gb) > 0);
  
          num_blocks -= num_blocks_at_qpi;
      }
  
      return 0;
  }
  
  /*
   * This function is called by unpack_dct_coeffs() to extract the VLCs from
   * the bitstream. The VLCs encode tokens which are used to unpack DCT
   * data. This function unpacks all the VLCs for either the Y plane or both
   * C planes, and is called for DC coefficients or different AC coefficient
   * levels (since different coefficient types require different VLC tables.
   *
   * This function returns a residual eob run. E.g, if a particular token gave
   * instructions to EOB the next 5 fragments and there were only 2 fragments
   * left in the current fragment range, 3 would be returned so that it could
   * be passed into the next call to this same function.
   */
  static int unpack_vlcs(Vp3DecodeContext *s, GetBitContext *gb,
                          VLC *table, int coeff_index,
                          int plane,
                          int eob_run)
  {
      int i, j = 0;
      int token;
      int zero_run = 0;
      DCTELEM coeff = 0;
      int bits_to_get;
      int blocks_ended;
      int coeff_i = 0;
      int num_coeffs = s->num_coded_frags[plane][coeff_index];
      int16_t *dct_tokens = s->dct_tokens[plane][coeff_index];
  
      /* local references to structure members to avoid repeated deferences */
      int *coded_fragment_list = s->coded_fragment_list[plane];
      Vp3Fragment *all_fragments = s->all_fragments;
      VLC_TYPE (*vlc_table)[2] = table->table;
  
      if (num_coeffs < 0)
          av_log(s->avctx, AV_LOG_ERROR, "Invalid number of coefficents at level %d\n", coeff_index);
  
      if (eob_run > num_coeffs) {
          coeff_i = blocks_ended = num_coeffs;
          eob_run -= num_coeffs;
      } else {
          coeff_i = blocks_ended = eob_run;
          eob_run = 0;
      }
  
      // insert fake EOB token to cover the split between planes or zzi
      if (blocks_ended)
          dct_tokens[j++] = blocks_ended << 2;
  
      while (coeff_i < num_coeffs && get_bits_left(gb) > 0) {
              /* decode a VLC into a token */
              token = get_vlc2(gb, vlc_table, 11, 3);
              /* use the token to get a zero run, a coefficient, and an eob run */
              if ((unsigned) token <= 6U) {
                  eob_run = eob_run_base[token];
                  if (eob_run_get_bits[token])
                      eob_run += get_bits(gb, eob_run_get_bits[token]);
  
                  // record only the number of blocks ended in this plane,
                  // any spill will be recorded in the next plane.
                  if (eob_run > num_coeffs - coeff_i) {
                      dct_tokens[j++] = TOKEN_EOB(num_coeffs - coeff_i);
                      blocks_ended   += num_coeffs - coeff_i;
                      eob_run        -= num_coeffs - coeff_i;
                      coeff_i         = num_coeffs;
                  } else {
                      dct_tokens[j++] = TOKEN_EOB(eob_run);
                      blocks_ended   += eob_run;
                      coeff_i        += eob_run;
                      eob_run = 0;
                  }
              } else if (token >= 0) {
                  bits_to_get = coeff_get_bits[token];
                  if (bits_to_get)
                      bits_to_get = get_bits(gb, bits_to_get);
                  coeff = coeff_tables[token][bits_to_get];
  
                  zero_run = zero_run_base[token];
                  if (zero_run_get_bits[token])
                      zero_run += get_bits(gb, zero_run_get_bits[token]);
  
                  if (zero_run) {
                      dct_tokens[j++] = TOKEN_ZERO_RUN(coeff, zero_run);
                  } else {
                      // Save DC into the fragment structure. DC prediction is
                      // done in raster order, so the actual DC can't be in with
                      // other tokens. We still need the token in dct_tokens[]
                      // however, or else the structure collapses on itself.
                      if (!coeff_index)
                          all_fragments[coded_fragment_list[coeff_i]].dc = coeff;
  
                      dct_tokens[j++] = TOKEN_COEFF(coeff);
                  }
  
                  if (coeff_index + zero_run > 64) {
                      av_log(s->avctx, AV_LOG_DEBUG, "Invalid zero run of %d with"
                             " %d coeffs left\n", zero_run, 64-coeff_index);
                      zero_run = 64 - coeff_index;
                  }
  
                  // zero runs code multiple coefficients,
                  // so don't try to decode coeffs for those higher levels
                  for (i = coeff_index+1; i <= coeff_index+zero_run; i++)
                      s->num_coded_frags[plane][i]--;
                  coeff_i++;
              } else {
                  av_log(s->avctx, AV_LOG_ERROR,
                         "Invalid token %d\n", token);
                  return -1;
              }
      }
  
      if (blocks_ended > s->num_coded_frags[plane][coeff_index])
          av_log(s->avctx, AV_LOG_ERROR, "More blocks ended than coded!\n");
  
      // decrement the number of blocks that have higher coeffecients for each
      // EOB run at this level
      if (blocks_ended)
          for (i = coeff_index+1; i < 64; i++)
              s->num_coded_frags[plane][i] -= blocks_ended;
  
      // setup the next buffer
      if (plane < 2)
          s->dct_tokens[plane+1][coeff_index] = dct_tokens + j;
      else if (coeff_index < 63)
          s->dct_tokens[0][coeff_index+1] = dct_tokens + j;
  
      return eob_run;
  }
  
  static void reverse_dc_prediction(Vp3DecodeContext *s,
                                    int first_fragment,
                                    int fragment_width,
                                    int fragment_height);
  /*
   * This function unpacks all of the DCT coefficient data from the
   * bitstream.
   */
  static int unpack_dct_coeffs(Vp3DecodeContext *s, GetBitContext *gb)
  {
      int i;
      int dc_y_table;
      int dc_c_table;
      int ac_y_table;
      int ac_c_table;
      int residual_eob_run = 0;
      VLC *y_tables[64];
      VLC *c_tables[64];
  
      s->dct_tokens[0][0] = s->dct_tokens_base;
  
      /* fetch the DC table indexes */
      dc_y_table = get_bits(gb, 4);
      dc_c_table = get_bits(gb, 4);
  
      /* unpack the Y plane DC coefficients */
      residual_eob_run = unpack_vlcs(s, gb, &s->dc_vlc[dc_y_table], 0,
          0, residual_eob_run);
      if (residual_eob_run < 0)
          return residual_eob_run;
  
      /* reverse prediction of the Y-plane DC coefficients */
      reverse_dc_prediction(s, 0, s->fragment_width[0], s->fragment_height[0]);
  
      /* unpack the C plane DC coefficients */
      residual_eob_run = unpack_vlcs(s, gb, &s->dc_vlc[dc_c_table], 0,
          1, residual_eob_run);
      if (residual_eob_run < 0)
          return residual_eob_run;
      residual_eob_run = unpack_vlcs(s, gb, &s->dc_vlc[dc_c_table], 0,
          2, residual_eob_run);
      if (residual_eob_run < 0)
          return residual_eob_run;
  
      /* reverse prediction of the C-plane DC coefficients */
      if (!(s->avctx->flags & CODEC_FLAG_GRAY))
      {
          reverse_dc_prediction(s, s->fragment_start[1],
              s->fragment_width[1], s->fragment_height[1]);
          reverse_dc_prediction(s, s->fragment_start[2],
              s->fragment_width[1], s->fragment_height[1]);
      }
  
      /* fetch the AC table indexes */
      ac_y_table = get_bits(gb, 4);
      ac_c_table = get_bits(gb, 4);
  
      /* build tables of AC VLC tables */
      for (i = 1; i <= 5; i++) {
          y_tables[i] = &s->ac_vlc_1[ac_y_table];
          c_tables[i] = &s->ac_vlc_1[ac_c_table];
      }
      for (i = 6; i <= 14; i++) {
          y_tables[i] = &s->ac_vlc_2[ac_y_table];
          c_tables[i] = &s->ac_vlc_2[ac_c_table];
      }
      for (i = 15; i <= 27; i++) {
          y_tables[i] = &s->ac_vlc_3[ac_y_table];
          c_tables[i] = &s->ac_vlc_3[ac_c_table];
      }
      for (i = 28; i <= 63; i++) {
          y_tables[i] = &s->ac_vlc_4[ac_y_table];
          c_tables[i] = &s->ac_vlc_4[ac_c_table];
      }
  
      /* decode all AC coefficents */
      for (i = 1; i <= 63; i++) {
              residual_eob_run = unpack_vlcs(s, gb, y_tables[i], i,
                  0, residual_eob_run);
              if (residual_eob_run < 0)
                  return residual_eob_run;
  
              residual_eob_run = unpack_vlcs(s, gb, c_tables[i], i,
                  1, residual_eob_run);
              if (residual_eob_run < 0)
                  return residual_eob_run;
              residual_eob_run = unpack_vlcs(s, gb, c_tables[i], i,
                  2, residual_eob_run);
              if (residual_eob_run < 0)
                  return residual_eob_run;
      }
  
      return 0;
  }
  
  /*
   * This function reverses the DC prediction for each coded fragment in
   * the frame. Much of this function is adapted directly from the original
   * VP3 source code.
   */
  #define COMPATIBLE_FRAME(x) \
    (compatible_frame[s->all_fragments[x].coding_method] == current_frame_type)
  #define DC_COEFF(u) s->all_fragments[u].dc
  
  static void reverse_dc_prediction(Vp3DecodeContext *s,
                                    int first_fragment,
                                    int fragment_width,
                                    int fragment_height)
  {
  
  #define PUL 8
  #define PU 4
  #define PUR 2
  #define PL 1
  
      int x, y;
      int i = first_fragment;
  
      int predicted_dc;
  
      /* DC values for the left, up-left, up, and up-right fragments */
      int vl, vul, vu, vur;
  
      /* indexes for the left, up-left, up, and up-right fragments */
      int l, ul, u, ur;
  
      /*
       * The 6 fields mean:
       *   0: up-left multiplier
       *   1: up multiplier
       *   2: up-right multiplier
       *   3: left multiplier
       */
      static const int predictor_transform[16][4] = {
          {  0,  0,  0,  0},
          {  0,  0,  0,128},        // PL
          {  0,  0,128,  0},        // PUR
          {  0,  0, 53, 75},        // PUR|PL
          {  0,128,  0,  0},        // PU
          {  0, 64,  0, 64},        // PU|PL
          {  0,128,  0,  0},        // PU|PUR
          {  0,  0, 53, 75},        // PU|PUR|PL
          {128,  0,  0,  0},        // PUL
          {  0,  0,  0,128},        // PUL|PL
          { 64,  0, 64,  0},        // PUL|PUR
          {  0,  0, 53, 75},        // PUL|PUR|PL
          {  0,128,  0,  0},        // PUL|PU
         {-104,116,  0,116},        // PUL|PU|PL
          { 24, 80, 24,  0},        // PUL|PU|PUR
         {-104,116,  0,116}         // PUL|PU|PUR|PL
      };
  
      /* This table shows which types of blocks can use other blocks for
       * prediction. For example, INTRA is the only mode in this table to
       * have a frame number of 0. That means INTRA blocks can only predict
       * from other INTRA blocks. There are 2 golden frame coding types;
       * blocks encoding in these modes can only predict from other blocks
       * that were encoded with these 1 of these 2 modes. */
      static const unsigned char compatible_frame[9] = {
          1,    /* MODE_INTER_NO_MV */
          0,    /* MODE_INTRA */
          1,    /* MODE_INTER_PLUS_MV */
          1,    /* MODE_INTER_LAST_MV */
          1,    /* MODE_INTER_PRIOR_MV */
          2,    /* MODE_USING_GOLDEN */
          2,    /* MODE_GOLDEN_MV */
          1,    /* MODE_INTER_FOUR_MV */
          3     /* MODE_COPY */
      };
      int current_frame_type;
  
      /* there is a last DC predictor for each of the 3 frame types */
      short last_dc[3];
  
      int transform = 0;
  
      vul = vu = vur = vl = 0;
      last_dc[0] = last_dc[1] = last_dc[2] = 0;
  
      /* for each fragment row... */
      for (y = 0; y < fragment_height; y++) {
  
          /* for each fragment in a row... */
          for (x = 0; x < fragment_width; x++, i++) {
  
              /* reverse prediction if this block was coded */
              if (s->all_fragments[i].coding_method != MODE_COPY) {
  
                  current_frame_type =
                      compatible_frame[s->all_fragments[i].coding_method];
  
                  transform= 0;
                  if(x){
                      l= i-1;
                      vl = DC_COEFF(l);
                      if(COMPATIBLE_FRAME(l))
                          transform |= PL;
                  }
                  if(y){
                      u= i-fragment_width;
                      vu = DC_COEFF(u);
                      if(COMPATIBLE_FRAME(u))
                          transform |= PU;
                      if(x){
                          ul= i-fragment_width-1;
                          vul = DC_COEFF(ul);
                          if(COMPATIBLE_FRAME(ul))
                              transform |= PUL;
                      }
                      if(x + 1 < fragment_width){
                          ur= i-fragment_width+1;
                          vur = DC_COEFF(ur);
                          if(COMPATIBLE_FRAME(ur))
                              transform |= PUR;
                      }
                  }
  
                  if (transform == 0) {
  
                      /* if there were no fragments to predict from, use last
                       * DC saved */
                      predicted_dc = last_dc[current_frame_type];
                  } else {
  
                      /* apply the appropriate predictor transform */
                      predicted_dc =
                          (predictor_transform[transform][0] * vul) +
                          (predictor_transform[transform][1] * vu) +
                          (predictor_transform[transform][2] * vur) +
                          (predictor_transform[transform][3] * vl);
  
                      predicted_dc /= 128;
  
                      /* check for outranging on the [ul u l] and
                       * [ul u ur l] predictors */
                      if ((transform == 15) || (transform == 13)) {
                          if (FFABS(predicted_dc - vu) > 128)
                              predicted_dc = vu;
                          else if (FFABS(predicted_dc - vl) > 128)
                              predicted_dc = vl;
                          else if (FFABS(predicted_dc - vul) > 128)
                              predicted_dc = vul;
                      }
                  }
  
                  /* at long last, apply the predictor */
                  DC_COEFF(i) += predicted_dc;
                  /* save the DC */
                  last_dc[current_frame_type] = DC_COEFF(i);
              }
          }
      }
  }
  
  static void apply_loop_filter(Vp3DecodeContext *s, int plane, int ystart, int yend)
  {
      int x, y;
      int *bounding_values= s->bounding_values_array+127;
  
      int width           = s->fragment_width[!!plane];
      int height          = s->fragment_height[!!plane];
      int fragment        = s->fragment_start        [plane] + ystart * width;
      int stride          = s->current_frame.linesize[plane];
      uint8_t *plane_data = s->current_frame.data    [plane];
      if (!s->flipped_image) stride = -stride;
      plane_data += s->data_offset[plane] + 8*ystart*stride;
  
      for (y = ystart; y < yend; y++) {
  
          for (x = 0; x < width; x++) {
              /* This code basically just deblocks on the edges of coded blocks.
               * However, it has to be much more complicated because of the
               * braindamaged deblock ordering used in VP3/Theora. Order matters
               * because some pixels get filtered twice. */
              if( s->all_fragments[fragment].coding_method != MODE_COPY )
              {
                  /* do not perform left edge filter for left columns frags */
                  if (x > 0) {
                      s->dsp.vp3_h_loop_filter(
                          plane_data + 8*x,
                          stride, bounding_values);
                  }
  
                  /* do not perform top edge filter for top row fragments */
                  if (y > 0) {
                      s->dsp.vp3_v_loop_filter(
                          plane_data + 8*x,
                          stride, bounding_values);
                  }
  
                  /* do not perform right edge filter for right column
                   * fragments or if right fragment neighbor is also coded
                   * in this frame (it will be filtered in next iteration) */
                  if ((x < width - 1) &&
                      (s->all_fragments[fragment + 1].coding_method == MODE_COPY)) {
                      s->dsp.vp3_h_loop_filter(
                          plane_data + 8*x + 8,
                          stride, bounding_values);
                  }
  
                  /* do not perform bottom edge filter for bottom row
                   * fragments or if bottom fragment neighbor is also coded
                   * in this frame (it will be filtered in the next row) */
                  if ((y < height - 1) &&
                      (s->all_fragments[fragment + width].coding_method == MODE_COPY)) {
                      s->dsp.vp3_v_loop_filter(
                          plane_data + 8*x + 8*stride,
                          stride, bounding_values);
                  }
              }
  
              fragment++;
          }
          plane_data += 8*stride;
      }
  }
  
  /**
   * Pull DCT tokens from the 64 levels to decode and dequant the coefficients
   * for the next block in coding order
   */
  static inline int vp3_dequant(Vp3DecodeContext *s, Vp3Fragment *frag,
                                int plane, int inter, DCTELEM block[64])
  {
      int16_t *dequantizer = s->qmat[frag->qpi][inter][plane];
      uint8_t *perm = s->scantable.permutated;
      int i = 0;
  
      do {
          int token = *s->dct_tokens[plane][i];
          switch (token & 3) {
          case 0: // EOB
              if (--token < 4) // 0-3 are token types, so the EOB run must now be 0
                  s->dct_tokens[plane][i]++;
              else
                  *s->dct_tokens[plane][i] = token & ~3;
              goto end;
          case 1: // zero run
              s->dct_tokens[plane][i]++;
              i += (token >> 2) & 0x7f;
              if(i>63){
                  av_log(s->avctx, AV_LOG_ERROR, "Coefficient index overflow\n");
                  return -1;
              }
              block[perm[i]] = (token >> 9) * dequantizer[perm[i]];
              i++;
              break;
          case 2: // coeff
              block[perm[i]] = (token >> 2) * dequantizer[perm[i]];
              s->dct_tokens[plane][i++]++;
              break;
          default: // shouldn't happen
              return i;
          }
      } while (i < 64);
  end:
      // the actual DC+prediction is in the fragment structure
      block[0] = frag->dc * s->qmat[0][inter][plane][0];
      return i;
  }
  
  /**
   * called when all pixels up to row y are complete
   */
  static void vp3_draw_horiz_band(Vp3DecodeContext *s, int y)
  {
      int h, cy, i;
      int offset[AV_NUM_DATA_POINTERS];
  
      if (HAVE_THREADS && s->avctx->active_thread_type&FF_THREAD_FRAME) {
          int y_flipped = s->flipped_image ? s->avctx->height-y : y;
  
          // At the end of the frame, report INT_MAX instead of the height of the frame.
          // This makes the other threads' ff_thread_await_progress() calls cheaper, because
          // they don't have to clip their values.
          ff_thread_report_progress(&s->current_frame, y_flipped==s->avctx->height ? INT_MAX : y_flipped-1, 0);
      }
  
      if(s->avctx->draw_horiz_band==NULL)
          return;
  
      h= y - s->last_slice_end;
      s->last_slice_end= y;
      y -= h;
  
      if (!s->flipped_image) {
          y = s->avctx->height - y - h;
      }
  
      cy = y >> s->chroma_y_shift;
      offset[0] = s->current_frame.linesize[0]*y;
      offset[1] = s->current_frame.linesize[1]*cy;
      offset[2] = s->current_frame.linesize[2]*cy;
      for (i = 3; i < AV_NUM_DATA_POINTERS; i++)
          offset[i] = 0;
  
      emms_c();
      s->avctx->draw_horiz_band(s->avctx, &s->current_frame, offset, y, 3, h);
  }
  
  /**
   * Wait for the reference frame of the current fragment.
   * The progress value is in luma pixel rows.
   */
  static void await_reference_row(Vp3DecodeContext *s, Vp3Fragment *fragment, int motion_y, int y)
  {
      AVFrame *ref_frame;
      int ref_row;
      int border = motion_y&1;
  
      if (fragment->coding_method == MODE_USING_GOLDEN ||
          fragment->coding_method == MODE_GOLDEN_MV)
          ref_frame = &s->golden_frame;
      else
          ref_frame = &s->last_frame;
  
      ref_row = y + (motion_y>>1);
      ref_row = FFMAX(FFABS(ref_row), ref_row + 8 + border);
  
      ff_thread_await_progress(ref_frame, ref_row, 0);
  }
  
  /*
   * Perform the final rendering for a particular slice of data.
   * The slice number ranges from 0..(c_superblock_height - 1).
   */
  static void render_slice(Vp3DecodeContext *s, int slice)
  {
      int x, y, i, j, fragment;
      LOCAL_ALIGNED_16(DCTELEM, block, [64]);
      int motion_x = 0xdeadbeef, motion_y = 0xdeadbeef;
      int motion_halfpel_index;
      uint8_t *motion_source;
      int plane, first_pixel;
  
      if (slice >= s->c_superblock_height)
          return;
  
      for (plane = 0; plane < 3; plane++) {
          uint8_t *output_plane = s->current_frame.data    [plane] + s->data_offset[plane];
          uint8_t *  last_plane = s->   last_frame.data    [plane] + s->data_offset[plane];
          uint8_t *golden_plane = s-> golden_frame.data    [plane] + s->data_offset[plane];
          int stride            = s->current_frame.linesize[plane];
          int plane_width       = s->width  >> (plane && s->chroma_x_shift);
          int plane_height      = s->height >> (plane && s->chroma_y_shift);
          int8_t (*motion_val)[2] = s->motion_val[!!plane];
  
          int sb_x, sb_y        = slice << (!plane && s->chroma_y_shift);
          int slice_height      = sb_y + 1 + (!plane && s->chroma_y_shift);
          int slice_width       = plane ? s->c_superblock_width : s->y_superblock_width;
  
          int fragment_width    = s->fragment_width[!!plane];
          int fragment_height   = s->fragment_height[!!plane];
          int fragment_start    = s->fragment_start[plane];
          int do_await          = !plane && HAVE_THREADS && (s->avctx->active_thread_type&FF_THREAD_FRAME);
  
          if (!s->flipped_image) stride = -stride;
          if (CONFIG_GRAY && plane && (s->avctx->flags & CODEC_FLAG_GRAY))
              continue;
  
          /* for each superblock row in the slice (both of them)... */
          for (; sb_y < slice_height; sb_y++) {
  
              /* for each superblock in a row... */
              for (sb_x = 0; sb_x < slice_width; sb_x++) {
  
                  /* for each block in a superblock... */
                  for (j = 0; j < 16; j++) {
                      x = 4*sb_x + hilbert_offset[j][0];
                      y = 4*sb_y + hilbert_offset[j][1];
                      fragment = y*fragment_width + x;
  
                      i = fragment_start + fragment;
  
                      // bounds check
                      if (x >= fragment_width || y >= fragment_height)
                          continue;
  
                  first_pixel = 8*y*stride + 8*x;
  
                  if (do_await && s->all_fragments[i].coding_method != MODE_INTRA)
                      await_reference_row(s, &s->all_fragments[i], motion_val[fragment][1], (16*y) >> s->chroma_y_shift);
  
                  /* transform if this block was coded */
                  if (s->all_fragments[i].coding_method != MODE_COPY) {
                      if ((s->all_fragments[i].coding_method == MODE_USING_GOLDEN) ||
                          (s->all_fragments[i].coding_method == MODE_GOLDEN_MV))
                          motion_source= golden_plane;
                      else
                          motion_source= last_plane;
  
                      motion_source += first_pixel;
                      motion_halfpel_index = 0;
  
                      /* sort out the motion vector if this fragment is coded
                       * using a motion vector method */
                      if ((s->all_fragments[i].coding_method > MODE_INTRA) &&
                          (s->all_fragments[i].coding_method != MODE_USING_GOLDEN)) {
                          int src_x, src_y;
                          motion_x = motion_val[fragment][0];
                          motion_y = motion_val[fragment][1];
  
                          src_x= (motion_x>>1) + 8*x;
                          src_y= (motion_y>>1) + 8*y;
  
                          motion_halfpel_index = motion_x & 0x01;
                          motion_source += (motion_x >> 1);
  
                          motion_halfpel_index |= (motion_y & 0x01) << 1;
                          motion_source += ((motion_y >> 1) * stride);
  
                          if(src_x<0 || src_y<0 || src_x + 9 >= plane_width || src_y + 9 >= plane_height){
                              uint8_t *temp= s->edge_emu_buffer;
                              if(stride<0) temp -= 8*stride;
  
                              s->dsp.emulated_edge_mc(temp, motion_source, stride, 9, 9, src_x, src_y, plane_width, plane_height);
                              motion_source= temp;
                          }
                      }
  
  
                      /* first, take care of copying a block from either the
                       * previous or the golden frame */
                      if (s->all_fragments[i].coding_method != MODE_INTRA) {
                          /* Note, it is possible to implement all MC cases with
                             put_no_rnd_pixels_l2 which would look more like the
                             VP3 source but this would be slower as
                             put_no_rnd_pixels_tab is better optimzed */
                          if(motion_halfpel_index != 3){
                              s->dsp.put_no_rnd_pixels_tab[1][motion_halfpel_index](
                                  output_plane + first_pixel,
                                  motion_source, stride, 8);
                          }else{
                              int d= (motion_x ^ motion_y)>>31; // d is 0 if motion_x and _y have the same sign, else -1
                              s->dsp.put_no_rnd_pixels_l2[1](
                                  output_plane + first_pixel,
                                  motion_source - d,
                                  motion_source + stride + 1 + d,
                                  stride, 8);
                          }
                      }
  
                          s->dsp.clear_block(block);
  
                      /* invert DCT and place (or add) in final output */
  
                      if (s->all_fragments[i].coding_method == MODE_INTRA) {
                          vp3_dequant(s, s->all_fragments + i, plane, 0, block);
                          if(s->avctx->idct_algo!=FF_IDCT_VP3)
                              block[0] += 128<<3;
                          s->dsp.idct_put(
                              output_plane + first_pixel,
                              stride,
                              block);
                      } else {
                          if (vp3_dequant(s, s->all_fragments + i, plane, 1, block)) {
                          s->dsp.idct_add(
                              output_plane + first_pixel,
                              stride,
                              block);
                          } else {
                              s->dsp.vp3_idct_dc_add(output_plane + first_pixel, stride, block);
                          }
                      }
                  } else {
  
                      /* copy directly from the previous frame */
                      s->dsp.put_pixels_tab[1][0](
                          output_plane + first_pixel,
                          last_plane + first_pixel,
                          stride, 8);
  
                  }
                  }
              }
  
              // Filter up to the last row in the superblock row
              if (!s->skip_loop_filter)
                  apply_loop_filter(s, plane, 4*sb_y - !!sb_y, FFMIN(4*sb_y+3, fragment_height-1));
          }
      }
  
       /* this looks like a good place for slice dispatch... */
       /* algorithm:
        *   if (slice == s->macroblock_height - 1)
        *     dispatch (both last slice & 2nd-to-last slice);
        *   else if (slice > 0)
        *     dispatch (slice - 1);
        */
  
      vp3_draw_horiz_band(s, FFMIN((32 << s->chroma_y_shift) * (slice + 1) -16, s->height-16));
  }
  
  /// Allocate tables for per-frame data in Vp3DecodeContext
  static av_cold int allocate_tables(AVCodecContext *avctx)
  {
      Vp3DecodeContext *s = avctx->priv_data;
      int y_fragment_count, c_fragment_count;
  
      y_fragment_count = s->fragment_width[0] * s->fragment_height[0];
      c_fragment_count = s->fragment_width[1] * s->fragment_height[1];
  
      s->superblock_coding = av_malloc(s->superblock_count);
      s->all_fragments = av_malloc(s->fragment_count * sizeof(Vp3Fragment));
      s->coded_fragment_list[0] = av_malloc(s->fragment_count * sizeof(int));
      s->dct_tokens_base = av_malloc(64*s->fragment_count * sizeof(*s->dct_tokens_base));
      s->motion_val[0] = av_malloc(y_fragment_count * sizeof(*s->motion_val[0]));
      s->motion_val[1] = av_malloc(c_fragment_count * sizeof(*s->motion_val[1]));
  
      /* work out the block mapping tables */
      s->superblock_fragments = av_malloc(s->superblock_count * 16 * sizeof(int));
      s->macroblock_coding = av_malloc(s->macroblock_count + 1);
  
      if (!s->superblock_coding || !s->all_fragments || !s->dct_tokens_base ||
          !s->coded_fragment_list[0] || !s->superblock_fragments || !s->macroblock_coding ||
          !s->motion_val[0] || !s->motion_val[1]) {
          vp3_decode_end(avctx);
          return -1;
      }
  
      init_block_mapping(s);
  
      return 0;
  }
  
  static av_cold int vp3_decode_init(AVCodecContext *avctx)
  {
      Vp3DecodeContext *s = avctx->priv_data;
      int i, inter, plane;
      int c_width;
      int c_height;
      int y_fragment_count, c_fragment_count;
  
      if (avctx->codec_tag == MKTAG('V','P','3','0'))
          s->version = 0;
      else
          s->version = 1;
  
      s->avctx = avctx;
      s->width = FFALIGN(avctx->width, 16);
      s->height = FFALIGN(avctx->height, 16);
      if (avctx->pix_fmt == PIX_FMT_NONE)
          avctx->pix_fmt = PIX_FMT_YUV420P;
      avctx->chroma_sample_location = AVCHROMA_LOC_CENTER;
      if(avctx->idct_algo==FF_IDCT_AUTO)
          avctx->idct_algo=FF_IDCT_VP3;
      dsputil_init(&s->dsp, avctx);
  
      ff_init_scantable(s->dsp.idct_permutation, &s->scantable, ff_zigzag_direct);
  
      /* initialize to an impossible value which will force a recalculation
       * in the first frame decode */
      for (i = 0; i < 3; i++)
          s->qps[i] = -1;
  
      avcodec_get_chroma_sub_sample(avctx->pix_fmt, &s->chroma_x_shift, &s->chroma_y_shift);
  
      s->y_superblock_width = (s->width + 31) / 32;
      s->y_superblock_height = (s->height + 31) / 32;
      s->y_superblock_count = s->y_superblock_width * s->y_superblock_height;
  
      /* work out the dimensions for the C planes */
      c_width = s->width >> s->chroma_x_shift;
      c_height = s->height >> s->chroma_y_shift;
      s->c_superblock_width = (c_width + 31) / 32;
      s->c_superblock_height = (c_height + 31) / 32;
      s->c_superblock_count = s->c_superblock_width * s->c_superblock_height;
  
      s->superblock_count = s->y_superblock_count + (s->c_superblock_count * 2);
      s->u_superblock_start = s->y_superblock_count;
      s->v_superblock_start = s->u_superblock_start + s->c_superblock_count;
  
      s->macroblock_width = (s->width + 15) / 16;
      s->macroblock_height = (s->height + 15) / 16;
      s->macroblock_count = s->macroblock_width * s->macroblock_height;
  
      s->fragment_width[0] = s->width / FRAGMENT_PIXELS;
      s->fragment_height[0] = s->height / FRAGMENT_PIXELS;
      s->fragment_width[1]  = s->fragment_width[0]  >> s->chroma_x_shift;
      s->fragment_height[1] = s->fragment_height[0] >> s->chroma_y_shift;
  
      /* fragment count covers all 8x8 blocks for all 3 planes */
      y_fragment_count     = s->fragment_width[0] * s->fragment_height[0];
      c_fragment_count     = s->fragment_width[1] * s->fragment_height[1];
      s->fragment_count    = y_fragment_count + 2*c_fragment_count;
      s->fragment_start[1] = y_fragment_count;
      s->fragment_start[2] = y_fragment_count + c_fragment_count;
  
      if (!s->theora_tables)
      {
          for (i = 0; i < 64; i++) {
              s->coded_dc_scale_factor[i] = vp31_dc_scale_factor[i];
              s->coded_ac_scale_factor[i] = vp31_ac_scale_factor[i];
              s->base_matrix[0][i] = vp31_intra_y_dequant[i];
              s->base_matrix[1][i] = vp31_intra_c_dequant[i];
              s->base_matrix[2][i] = vp31_inter_dequant[i];
              s->filter_limit_values[i] = vp31_filter_limit_values[i];
          }
  
          for(inter=0; inter<2; inter++){
              for(plane=0; plane<3; plane++){
                  s->qr_count[inter][plane]= 1;
                  s->qr_size [inter][plane][0]= 63;
                  s->qr_base [inter][plane][0]=
                  s->qr_base [inter][plane][1]= 2*inter + (!!plane)*!inter;
              }
          }
  
          /* init VLC tables */
          for (i = 0; i < 16; i++) {
  
              /* DC histograms */
              init_vlc(&s->dc_vlc[i], 11, 32,
                  &dc_bias[i][0][1], 4, 2,
                  &dc_bias[i][0][0], 4, 2, 0);
  
              /* group 1 AC histograms */
              init_vlc(&s->ac_vlc_1[i], 11, 32,
                  &ac_bias_0[i][0][1], 4, 2,
                  &ac_bias_0[i][0][0], 4, 2, 0);
  
              /* group 2 AC histograms */
              init_vlc(&s->ac_vlc_2[i], 11, 32,
                  &ac_bias_1[i][0][1], 4, 2,
                  &ac_bias_1[i][0][0], 4, 2, 0);
  
              /* group 3 AC histograms */
              init_vlc(&s->ac_vlc_3[i], 11, 32,
                  &ac_bias_2[i][0][1], 4, 2,
                  &ac_bias_2[i][0][0], 4, 2, 0);
  
              /* group 4 AC histograms */
              init_vlc(&s->ac_vlc_4[i], 11, 32,
                  &ac_bias_3[i][0][1], 4, 2,
                  &ac_bias_3[i][0][0], 4, 2, 0);
          }
      } else {
  
          for (i = 0; i < 16; i++) {
              /* DC histograms */
              if (init_vlc(&s->dc_vlc[i], 11, 32,
                  &s->huffman_table[i][0][1], 8, 4,
                  &s->huffman_table[i][0][0], 8, 4, 0) < 0)
                  goto vlc_fail;
  
              /* group 1 AC histograms */
              if (init_vlc(&s->ac_vlc_1[i], 11, 32,
                  &s->huffman_table[i+16][0][1], 8, 4,
                  &s->huffman_table[i+16][0][0], 8, 4, 0) < 0)
                  goto vlc_fail;
  
              /* group 2 AC histograms */
              if (init_vlc(&s->ac_vlc_2[i], 11, 32,
                  &s->huffman_table[i+16*2][0][1], 8, 4,
                  &s->huffman_table[i+16*2][0][0], 8, 4, 0) < 0)
                  goto vlc_fail;
  
              /* group 3 AC histograms */
              if (init_vlc(&s->ac_vlc_3[i], 11, 32,
                  &s->huffman_table[i+16*3][0][1], 8, 4,
                  &s->huffman_table[i+16*3][0][0], 8, 4, 0) < 0)
                  goto vlc_fail;
  
              /* group 4 AC histograms */
              if (init_vlc(&s->ac_vlc_4[i], 11, 32,
                  &s->huffman_table[i+16*4][0][1], 8, 4,
                  &s->huffman_table[i+16*4][0][0], 8, 4, 0) < 0)
                  goto vlc_fail;
          }
      }
  
      init_vlc(&s->superblock_run_length_vlc, 6, 34,
          &superblock_run_length_vlc_table[0][1], 4, 2,
          &superblock_run_length_vlc_table[0][0], 4, 2, 0);
  
      init_vlc(&s->fragment_run_length_vlc, 5, 30,
          &fragment_run_length_vlc_table[0][1], 4, 2,
          &fragment_run_length_vlc_table[0][0], 4, 2, 0);
  
      init_vlc(&s->mode_code_vlc, 3, 8,
          &mode_code_vlc_table[0][1], 2, 1,
          &mode_code_vlc_table[0][0], 2, 1, 0);
  
      init_vlc(&s->motion_vector_vlc, 6, 63,
          &motion_vector_vlc_table[0][1], 2, 1,
          &motion_vector_vlc_table[0][0], 2, 1, 0);
  
      for (i = 0; i < 3; i++) {
          s->current_frame.data[i] = NULL;
          s->last_frame.data[i] = NULL;
          s->golden_frame.data[i] = NULL;
      }
  
      return allocate_tables(avctx);
  
  vlc_fail:
      av_log(avctx, AV_LOG_FATAL, "Invalid huffman table\n");
      return -1;
  }
  
  /// Release and shuffle frames after decode finishes
  static void update_frames(AVCodecContext *avctx)
  {
      Vp3DecodeContext *s = avctx->priv_data;
  
      /* release the last frame, if it is allocated and if it is not the
       * golden frame */
      if (s->last_frame.data[0] && s->last_frame.type != FF_BUFFER_TYPE_COPY)
          ff_thread_release_buffer(avctx, &s->last_frame);
  
      /* shuffle frames (last = current) */
      s->last_frame= s->current_frame;
  
      if (s->keyframe) {
          if (s->golden_frame.data[0])
              ff_thread_release_buffer(avctx, &s->golden_frame);
          s->golden_frame = s->current_frame;
          s->last_frame.type = FF_BUFFER_TYPE_COPY;
      }
  
      s->current_frame.data[0]= NULL; /* ensure that we catch any access to this released frame */
  }
  
  static int vp3_update_thread_context(AVCodecContext *dst, const AVCodecContext *src)
  {
      Vp3DecodeContext *s = dst->priv_data, *s1 = src->priv_data;
      int qps_changed = 0, i, err;
  
  #define copy_fields(to, from, start_field, end_field) memcpy(&to->start_field, &from->start_field, (char*)&to->end_field - (char*)&to->start_field)
  
      if (!s1->current_frame.data[0]
          ||s->width != s1->width
          ||s->height!= s1->height) {
          if (s != s1)
              copy_fields(s, s1, golden_frame, current_frame);
          return -1;
      }
  
      if (s != s1) {
          // init tables if the first frame hasn't been decoded
          if (!s->current_frame.data[0]) {
              int y_fragment_count, c_fragment_count;
              s->avctx = dst;
              err = allocate_tables(dst);
              if (err)
                  return err;
              y_fragment_count = s->fragment_width[0] * s->fragment_height[0];
              c_fragment_count = s->fragment_width[1] * s->fragment_height[1];
              memcpy(s->motion_val[0], s1->motion_val[0], y_fragment_count * sizeof(*s->motion_val[0]));
              memcpy(s->motion_val[1], s1->motion_val[1], c_fragment_count * sizeof(*s->motion_val[1]));
          }
  
          // copy previous frame data
          copy_fields(s, s1, golden_frame, dsp);
  
          // copy qscale data if necessary
          for (i = 0; i < 3; i++) {
              if (s->qps[i] != s1->qps[1]) {
                  qps_changed = 1;
                  memcpy(&s->qmat[i], &s1->qmat[i], sizeof(s->qmat[i]));
              }
          }
  
          if (s->qps[0] != s1->qps[0])
              memcpy(&s->bounding_values_array, &s1->bounding_values_array, sizeof(s->bounding_values_array));
  
          if (qps_changed)
              copy_fields(s, s1, qps, superblock_count);
  #undef copy_fields
      }
  
      update_frames(dst);
  
      return 0;
  }
  
  static int vp3_decode_frame(AVCodecContext *avctx,
                              void *data, int *data_size,
                              AVPacket *avpkt)
  {
      const uint8_t *buf = avpkt->data;
      int buf_size = avpkt->size;
      Vp3DecodeContext *s = avctx->priv_data;
      GetBitContext gb;
      int i;
  
      init_get_bits(&gb, buf, buf_size * 8);
  
      if (s->theora && get_bits1(&gb))
      {
          av_log(avctx, AV_LOG_ERROR, "Header packet passed to frame decoder, skipping\n");
          return -1;
      }
  
      s->keyframe = !get_bits1(&gb);
      if (!s->theora)
          skip_bits(&gb, 1);
      for (i = 0; i < 3; i++)
          s->last_qps[i] = s->qps[i];
  
      s->nqps=0;
      do{
          s->qps[s->nqps++]= get_bits(&gb, 6);
      } while(s->theora >= 0x030200 && s->nqps<3 && get_bits1(&gb));
      for (i = s->nqps; i < 3; i++)
          s->qps[i] = -1;
  
      if (s->avctx->debug & FF_DEBUG_PICT_INFO)
          av_log(s->avctx, AV_LOG_INFO, " VP3 %sframe #%d: Q index = %d\n",
              s->keyframe?"key":"", avctx->frame_number+1, s->qps[0]);
  
      s->skip_loop_filter = !s->filter_limit_values[s->qps[0]] ||
          avctx->skip_loop_filter >= (s->keyframe ? AVDISCARD_ALL : AVDISCARD_NONKEY);
  
      if (s->qps[0] != s->last_qps[0])
          init_loop_filter(s);
  
      for (i = 0; i < s->nqps; i++)
          // reinit all dequantizers if the first one changed, because
          // the DC of the first quantizer must be used for all matrices
          if (s->qps[i] != s->last_qps[i] || s->qps[0] != s->last_qps[0])
              init_dequantizer(s, i);
  
      if (avctx->skip_frame >= AVDISCARD_NONKEY && !s->keyframe)
          return buf_size;
  
      s->current_frame.reference = 3;
      s->current_frame.pict_type = s->keyframe ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
      s->current_frame.key_frame = s->keyframe;
      if (ff_thread_get_buffer(avctx, &s->current_frame) < 0) {
          av_log(s->avctx, AV_LOG_ERROR, "get_buffer() failed\n");
          goto error;
      }
  
      if (!s->edge_emu_buffer)
          s->edge_emu_buffer = av_malloc(9*FFABS(s->current_frame.linesize[0]));
  
      if (s->keyframe) {
          if (!s->theora)
          {
              skip_bits(&gb, 4); /* width code */
              skip_bits(&gb, 4); /* height code */
              if (s->version)
              {
                  s->version = get_bits(&gb, 5);
                  if (avctx->frame_number == 0)
                      av_log(s->avctx, AV_LOG_DEBUG, "VP version: %d\n", s->version);
              }
          }
          if (s->version || s->theora)
          {
                  if (get_bits1(&gb))
                      av_log(s->avctx, AV_LOG_ERROR, "Warning, unsupported keyframe coding type?!\n");
              skip_bits(&gb, 2); /* reserved? */
          }
      } else {
          if (!s->golden_frame.data[0]) {
              av_log(s->avctx, AV_LOG_WARNING, "vp3: first frame not a keyframe\n");
  
              s->golden_frame.reference = 3;
              s->golden_frame.pict_type = AV_PICTURE_TYPE_I;
              if (ff_thread_get_buffer(avctx, &s->golden_frame) < 0) {
                  av_log(s->avctx, AV_LOG_ERROR, "get_buffer() failed\n");
                  goto error;
              }
              s->last_frame = s->golden_frame;
              s->last_frame.type = FF_BUFFER_TYPE_COPY;
              ff_thread_report_progress(&s->last_frame, INT_MAX, 0);
          }
      }
  
      memset(s->all_fragments, 0, s->fragment_count * sizeof(Vp3Fragment));
      ff_thread_finish_setup(avctx);
  
      if (unpack_superblocks(s, &gb)){
          av_log(s->avctx, AV_LOG_ERROR, "error in unpack_superblocks\n");
          goto error;
      }
      if (unpack_modes(s, &gb)){
          av_log(s->avctx, AV_LOG_ERROR, "error in unpack_modes\n");
          goto error;
      }
      if (unpack_vectors(s, &gb)){
          av_log(s->avctx, AV_LOG_ERROR, "error in unpack_vectors\n");
          goto error;
      }
      if (unpack_block_qpis(s, &gb)){
          av_log(s->avctx, AV_LOG_ERROR, "error in unpack_block_qpis\n");
          goto error;
      }
      if (unpack_dct_coeffs(s, &gb)){
          av_log(s->avctx, AV_LOG_ERROR, "error in unpack_dct_coeffs\n");
          goto error;
      }
  
      for (i = 0; i < 3; i++) {
          int height = s->height >> (i && s->chroma_y_shift);
          if (s->flipped_image)
              s->data_offset[i] = 0;
          else
              s->data_offset[i] = (height-1) * s->current_frame.linesize[i];
      }
  
      s->last_slice_end = 0;
      for (i = 0; i < s->c_superblock_height; i++)
          render_slice(s, i);
  
      // filter the last row
      for (i = 0; i < 3; i++) {
          int row = (s->height >> (3+(i && s->chroma_y_shift))) - 1;
          apply_loop_filter(s, i, row, row+1);
      }
      vp3_draw_horiz_band(s, s->avctx->height);
  
      *data_size=sizeof(AVFrame);
      *(AVFrame*)data= s->current_frame;
  
      if (!HAVE_THREADS || !(s->avctx->active_thread_type&FF_THREAD_FRAME))
          update_frames(avctx);
  
      return buf_size;
  
  error:
      ff_thread_report_progress(&s->current_frame, INT_MAX, 0);
  
      if (!HAVE_THREADS || !(s->avctx->active_thread_type&FF_THREAD_FRAME))
          avctx->release_buffer(avctx, &s->current_frame);
  
      return -1;
  }
  
  static void vp3_decode_flush(AVCodecContext *avctx);
  
  static av_cold int vp3_decode_end(AVCodecContext *avctx)
  {
      Vp3DecodeContext *s = avctx->priv_data;
      int i;
  
      av_free(s->superblock_coding);
      av_free(s->all_fragments);
      av_free(s->coded_fragment_list[0]);
      av_free(s->dct_tokens_base);
      av_free(s->superblock_fragments);
      av_free(s->macroblock_coding);
      av_free(s->motion_val[0]);
      av_free(s->motion_val[1]);
      av_free(s->edge_emu_buffer);
  
      if (avctx->internal->is_copy)
          return 0;
  
      for (i = 0; i < 16; i++) {
          free_vlc(&s->dc_vlc[i]);
          free_vlc(&s->ac_vlc_1[i]);
          free_vlc(&s->ac_vlc_2[i]);
          free_vlc(&s->ac_vlc_3[i]);
          free_vlc(&s->ac_vlc_4[i]);
      }
  
      free_vlc(&s->superblock_run_length_vlc);
      free_vlc(&s->fragment_run_length_vlc);
      free_vlc(&s->mode_code_vlc);
      free_vlc(&s->motion_vector_vlc);
  
      /* release all frames */
      vp3_decode_flush(avctx);
  
      return 0;
  }
  
  static int read_huffman_tree(AVCodecContext *avctx, GetBitContext *gb)
  {
      Vp3DecodeContext *s = avctx->priv_data;
  
      if (get_bits1(gb)) {
          int token;
          if (s->entries >= 32) { /* overflow */
              av_log(avctx, AV_LOG_ERROR, "huffman tree overflow\n");
              return -1;
          }
          token = get_bits(gb, 5);
          //av_log(avctx, AV_LOG_DEBUG, "hti %d hbits %x token %d entry : %d size %d\n", s->hti, s->hbits, token, s->entries, s->huff_code_size);
          s->huffman_table[s->hti][token][0] = s->hbits;
          s->huffman_table[s->hti][token][1] = s->huff_code_size;
          s->entries++;
      }
      else {
          if (s->huff_code_size >= 32) {/* overflow */
              av_log(avctx, AV_LOG_ERROR, "huffman tree overflow\n");
              return -1;
          }
          s->huff_code_size++;
          s->hbits <<= 1;
          if (read_huffman_tree(avctx, gb))
              return -1;
          s->hbits |= 1;
          if (read_huffman_tree(avctx, gb))
              return -1;
          s->hbits >>= 1;
          s->huff_code_size--;
      }
      return 0;
  }
  
  #if CONFIG_THEORA_DECODER
  static const enum PixelFormat theora_pix_fmts[4] = {
      PIX_FMT_YUV420P, PIX_FMT_NONE, PIX_FMT_YUV422P, PIX_FMT_YUV444P
  };
  
  static int theora_decode_header(AVCodecContext *avctx, GetBitContext *gb)
  {
      Vp3DecodeContext *s = avctx->priv_data;
      int visible_width, visible_height, colorspace;
      int offset_x = 0, offset_y = 0;
      AVRational fps, aspect;
  
      s->theora = get_bits_long(gb, 24);
      av_log(avctx, AV_LOG_DEBUG, "Theora bitstream version %X\n", s->theora);
  
      /* 3.2.0 aka alpha3 has the same frame orientation as original vp3 */
      /* but previous versions have the image flipped relative to vp3 */
      if (s->theora < 0x030200)
      {
          s->flipped_image = 1;
          av_log(avctx, AV_LOG_DEBUG, "Old (<alpha3) Theora bitstream, flipped image\n");
      }
  
      visible_width  = s->width  = get_bits(gb, 16) << 4;
      visible_height = s->height = get_bits(gb, 16) << 4;
  
      if(av_image_check_size(s->width, s->height, 0, avctx)){
          av_log(avctx, AV_LOG_ERROR, "Invalid dimensions (%dx%d)\n", s->width, s->height);
          s->width= s->height= 0;
          return -1;
      }
  
      if (s->theora >= 0x030200) {
          visible_width  = get_bits_long(gb, 24);
          visible_height = get_bits_long(gb, 24);
  
          offset_x = get_bits(gb, 8); /* offset x */
          offset_y = get_bits(gb, 8); /* offset y, from bottom */
      }
  
      fps.num = get_bits_long(gb, 32);
      fps.den = get_bits_long(gb, 32);
      if (fps.num && fps.den) {
          av_reduce(&avctx->time_base.num, &avctx->time_base.den,
                    fps.den, fps.num, 1<<30);
      }
  
      aspect.num = get_bits_long(gb, 24);
      aspect.den = get_bits_long(gb, 24);
      if (aspect.num && aspect.den) {
          av_reduce(&avctx->sample_aspect_ratio.num,
                    &avctx->sample_aspect_ratio.den,
                    aspect.num, aspect.den, 1<<30);
      }
  
      if (s->theora < 0x030200)
          skip_bits(gb, 5); /* keyframe frequency force */
      colorspace = get_bits(gb, 8);
      skip_bits(gb, 24); /* bitrate */
  
      skip_bits(gb, 6); /* quality hint */
  
      if (s->theora >= 0x030200)
      {
          skip_bits(gb, 5); /* keyframe frequency force */
          avctx->pix_fmt = theora_pix_fmts[get_bits(gb, 2)];
          skip_bits(gb, 3); /* reserved */
      }
  
  //    align_get_bits(gb);
  
      if (   visible_width  <= s->width  && visible_width  > s->width-16
          && visible_height <= s->height && visible_height > s->height-16
          && !offset_x && (offset_y == s->height - visible_height))
          avcodec_set_dimensions(avctx, visible_width, visible_height);
      else
          avcodec_set_dimensions(avctx, s->width, s->height);
  
      if (colorspace == 1) {
          avctx->color_primaries = AVCOL_PRI_BT470M;
      } else if (colorspace == 2) {
          avctx->color_primaries = AVCOL_PRI_BT470BG;
      }
      if (colorspace == 1 || colorspace == 2) {
          avctx->colorspace = AVCOL_SPC_BT470BG;
          avctx->color_trc  = AVCOL_TRC_BT709;
      }
  
      return 0;
  }
  
  static int theora_decode_tables(AVCodecContext *avctx, GetBitContext *gb)
  {
      Vp3DecodeContext *s = avctx->priv_data;
      int i, n, matrices, inter, plane;
  
      if (s->theora >= 0x030200) {
          n = get_bits(gb, 3);
          /* loop filter limit values table */
          if (n)
              for (i = 0; i < 64; i++)
                  s->filter_limit_values[i] = get_bits(gb, n);
      }
  
      if (s->theora >= 0x030200)
          n = get_bits(gb, 4) + 1;
      else
          n = 16;
      /* quality threshold table */
      for (i = 0; i < 64; i++)
          s->coded_ac_scale_factor[i] = get_bits(gb, n);
  
      if (s->theora >= 0x030200)
          n = get_bits(gb, 4) + 1;
      else
          n = 16;
      /* dc scale factor table */
      for (i = 0; i < 64; i++)
          s->coded_dc_scale_factor[i] = get_bits(gb, n);
  
      if (s->theora >= 0x030200)
          matrices = get_bits(gb, 9) + 1;
      else
          matrices = 3;
  
      if(matrices > 384){
          av_log(avctx, AV_LOG_ERROR, "invalid number of base matrixes\n");
          return -1;
      }
  
      for(n=0; n<matrices; n++){
          for (i = 0; i < 64; i++)
              s->base_matrix[n][i]= get_bits(gb, 8);
      }
  
      for (inter = 0; inter <= 1; inter++) {
          for (plane = 0; plane <= 2; plane++) {
              int newqr= 1;
              if (inter || plane > 0)
                  newqr = get_bits1(gb);
              if (!newqr) {
                  int qtj, plj;
                  if(inter && get_bits1(gb)){
                      qtj = 0;
                      plj = plane;
                  }else{
                      qtj= (3*inter + plane - 1) / 3;
                      plj= (plane + 2) % 3;
                  }
                  s->qr_count[inter][plane]= s->qr_count[qtj][plj];
                  memcpy(s->qr_size[inter][plane], s->qr_size[qtj][plj], sizeof(s->qr_size[0][0]));
                  memcpy(s->qr_base[inter][plane], s->qr_base[qtj][plj], sizeof(s->qr_base[0][0]));
              } else {
                  int qri= 0;
                  int qi = 0;
  
                  for(;;){
                      i= get_bits(gb, av_log2(matrices-1)+1);
                      if(i>= matrices){
                          av_log(avctx, AV_LOG_ERROR, "invalid base matrix index\n");
                          return -1;
                      }
                      s->qr_base[inter][plane][qri]= i;
                      if(qi >= 63)
                          break;
                      i = get_bits(gb, av_log2(63-qi)+1) + 1;
                      s->qr_size[inter][plane][qri++]= i;
                      qi += i;
                  }
  
                  if (qi > 63) {
                      av_log(avctx, AV_LOG_ERROR, "invalid qi %d > 63\n", qi);
                      return -1;
                  }
                  s->qr_count[inter][plane]= qri;
              }
          }
      }
  
      /* Huffman tables */
      for (s->hti = 0; s->hti < 80; s->hti++) {
          s->entries = 0;
          s->huff_code_size = 1;
          if (!get_bits1(gb)) {
              s->hbits = 0;
              if(read_huffman_tree(avctx, gb))
                  return -1;
              s->hbits = 1;
              if(read_huffman_tree(avctx, gb))
                  return -1;
          }
      }
  
      s->theora_tables = 1;
  
      return 0;
  }
  
  static av_cold int theora_decode_init(AVCodecContext *avctx)
  {
      Vp3DecodeContext *s = avctx->priv_data;
      GetBitContext gb;
      int ptype;
      uint8_t *header_start[3];
      int header_len[3];
      int i;
  
      s->theora = 1;
  
      if (!avctx->extradata_size)
      {
          av_log(avctx, AV_LOG_ERROR, "Missing extradata!\n");
          return -1;
      }
  
      if (avpriv_split_xiph_headers(avctx->extradata, avctx->extradata_size,
                                42, header_start, header_len) < 0) {
          av_log(avctx, AV_LOG_ERROR, "Corrupt extradata\n");
          return -1;
      }
  
    for(i=0;i<3;i++) {
      init_get_bits(&gb, header_start[i], header_len[i] * 8);
  
      ptype = get_bits(&gb, 8);
  
       if (!(ptype & 0x80))
       {
          av_log(avctx, AV_LOG_ERROR, "Invalid extradata!\n");
  //        return -1;
       }
  
      // FIXME: Check for this as well.
      skip_bits_long(&gb, 6*8); /* "theora" */
  
      switch(ptype)
      {
          case 0x80:
              theora_decode_header(avctx, &gb);
                  break;
          case 0x81:
  // FIXME: is this needed? it breaks sometimes
  //            theora_decode_comments(avctx, gb);
              break;
          case 0x82:
              if (theora_decode_tables(avctx, &gb))
                  return -1;
              break;
          default:
              av_log(avctx, AV_LOG_ERROR, "Unknown Theora config packet: %d\n", ptype&~0x80);
              break;
      }
      if(ptype != 0x81 && 8*header_len[i] != get_bits_count(&gb))
          av_log(avctx, AV_LOG_WARNING, "%d bits left in packet %X\n", 8*header_len[i] - get_bits_count(&gb), ptype);
      if (s->theora < 0x030200)
          break;
    }
  
      return vp3_decode_init(avctx);
  }
  
  static void vp3_decode_flush(AVCodecContext *avctx)
  {
      Vp3DecodeContext *s = avctx->priv_data;
  
      if (s->golden_frame.data[0]) {
          if (s->golden_frame.data[0] == s->last_frame.data[0])
              memset(&s->last_frame, 0, sizeof(AVFrame));
          if (s->current_frame.data[0] == s->golden_frame.data[0])
              memset(&s->current_frame, 0, sizeof(AVFrame));
          ff_thread_release_buffer(avctx, &s->golden_frame);
      }
      if (s->last_frame.data[0]) {
          if (s->current_frame.data[0] == s->last_frame.data[0])
              memset(&s->current_frame, 0, sizeof(AVFrame));
          ff_thread_release_buffer(avctx, &s->last_frame);
      }
      if (s->current_frame.data[0])
          ff_thread_release_buffer(avctx, &s->current_frame);
  }
  
  static int vp3_init_thread_copy(AVCodecContext *avctx)
  {
      Vp3DecodeContext *s = avctx->priv_data;
  
      s->superblock_coding      = NULL;
      s->all_fragments          = NULL;
      s->coded_fragment_list[0] = NULL;
      s->dct_tokens_base        = NULL;
      s->superblock_fragments   = NULL;
      s->macroblock_coding      = NULL;
      s->motion_val[0]          = NULL;
      s->motion_val[1]          = NULL;
      s->edge_emu_buffer        = NULL;
  
      return 0;
  }
  
  AVCodec ff_theora_decoder = {
      .name           = "theora",
      .type           = AVMEDIA_TYPE_VIDEO,
      .id             = CODEC_ID_THEORA,
      .priv_data_size = sizeof(Vp3DecodeContext),
      .init           = theora_decode_init,
      .close          = vp3_decode_end,
      .decode         = vp3_decode_frame,
      .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_FRAME_THREADS,
      .flush = vp3_decode_flush,
      .long_name = NULL_IF_CONFIG_SMALL("Theora"),
      .init_thread_copy      = ONLY_IF_THREADS_ENABLED(vp3_init_thread_copy),
      .update_thread_context = ONLY_IF_THREADS_ENABLED(vp3_update_thread_context)
  };
  #endif
  
  AVCodec ff_vp3_decoder = {
      .name           = "vp3",
      .type           = AVMEDIA_TYPE_VIDEO,
      .id             = CODEC_ID_VP3,
      .priv_data_size = sizeof(Vp3DecodeContext),
      .init           = vp3_decode_init,
      .close          = vp3_decode_end,
      .decode         = vp3_decode_frame,
      .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_FRAME_THREADS,
      .flush = vp3_decode_flush,
      .long_name = NULL_IF_CONFIG_SMALL("On2 VP3"),
      .init_thread_copy      = ONLY_IF_THREADS_ENABLED(vp3_init_thread_copy),
      .update_thread_context = ONLY_IF_THREADS_ENABLED(vp3_update_thread_context)
  };
  