/*

  * 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 libavcodec/vp3.c

  * 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 <unistd.h>
 
 #include "avcodec.h"
 #include "dsputil.h"

 #include "bitstream.h"

 
 #include "vp3data.h"

 #include "xiph.h"

 
 #define FRAGMENT_PIXELS 8
 

 static av_cold int vp3_decode_end(AVCodecContext *avctx);
 

 typedef struct Coeff {
     struct Coeff *next;
     DCTELEM coeff;
     uint8_t index;
 } Coeff;
 
 //FIXME split things out into their own arrays

 typedef struct Vp3Fragment {

     Coeff *next_coeff;

     /* address of first pixel taking into account which plane the fragment
      * lives on as well as the plane stride */
     int first_pixel;
     /* this is the macroblock that the fragment belongs to */

     uint16_t macroblock;
     uint8_t coding_method;
     int8_t motion_x;
     int8_t motion_y;

 } Vp3Fragment;
 
 #define SB_NOT_CODED        0
 #define SB_PARTIALLY_CODED  1
 #define SB_FULLY_CODED      2
 
 #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 },
 
 };
 
 #define MIN_DEQUANT_VAL 2
 
 typedef struct Vp3DecodeContext {
     AVCodecContext *avctx;

     int theora, theora_tables;

     int version;

     int width, height;
     AVFrame golden_frame;
     AVFrame last_frame;
     AVFrame current_frame;
     int keyframe;
     DSPContext dsp;

     int flipped_image;

     int qis[3];
     int nqis;

     int quality_index;
     int last_quality_index;
 
     int superblock_count;

     int y_superblock_width;
     int y_superblock_height;
     int c_superblock_width;
     int c_superblock_height;

     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;
     int fragment_height;
 
     Vp3Fragment *all_fragments;

     uint8_t *coeff_counts;

     Coeff *coeffs;
     Coeff *next_coeff;

     int fragment_start[3];

     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 indexes into the all_fragments array indicating

      * which of the fragments are coded */
     int *coded_fragment_list;
     int coded_fragment_list_index;

     int pixel_addresses_initialized;

 
     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[2][4][64]);        //<qmat[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 table contains superblock_count * 4 entries. Each set of 4

      * numbers corresponds to the macroblock indexes 0..3 of the superblock.

      * An entry will be -1 to indicate that no entry corresponds to that
      * index. */
     int *superblock_macroblocks;
 
     /* This table contains macroblock_count * 6 entries. Each set of 6

      * numbers corresponds to the fragment indexes 0..5 which comprise

      * the macroblock (4 Y fragments and 2 C fragments). */
     int *macroblock_fragments;

     /* This is an array that indicates how a particular macroblock

      * is coded. */

     unsigned char *macroblock_coding;

     int first_coded_y_fragment;
     int first_coded_c_fragment;
     int last_coded_y_fragment;
     int last_coded_c_fragment;
 

     uint8_t edge_emu_buffer[9*2048]; //FIXME dynamic alloc

     int8_t qscale_table[2048]; //FIXME dynamic alloc (width+15)/16

     /* Huffman decode */
     int hti;
     unsigned int hbits;
     int entries;
     int huff_code_size;
     uint16_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

  *
  * Returns 0 is successful; returns 1 if *anything* went wrong.

  */

 static int init_block_mapping(Vp3DecodeContext *s)

 {
     int i, j;
     signed int hilbert_walk_mb[4];
 
     int current_fragment = 0;
     int current_width = 0;
     int current_height = 0;
     int right_edge = 0;
     int bottom_edge = 0;
     int superblock_row_inc = 0;
     int *hilbert = NULL;
     int mapping_index = 0;
 
     int current_macroblock;
     int c_fragment;
 
     signed char travel_width[16] = {

          1,  1,  0, -1,

          0,  0,  1,  0,
          1,  0,  1,  0,
          0, -1,  0,  1
     };
 
     signed char travel_height[16] = {
          0,  0,  1,  0,
          1,  1,  0, -1,
          0,  1,  0, -1,
         -1,  0, -1,  0
     };
 
     signed char travel_width_mb[4] = {
          1,  0,  1,  0
     };
 
     signed char travel_height_mb[4] = {
          0,  1,  0, -1
     };
 
     hilbert_walk_mb[0] = 1;
     hilbert_walk_mb[1] = s->macroblock_width;
     hilbert_walk_mb[2] = 1;
     hilbert_walk_mb[3] = -s->macroblock_width;
 
     /* iterate through each superblock (all planes) and map the fragments */
     for (i = 0; i < s->superblock_count; i++) {
         /* time to re-assign the limits? */
         if (i == 0) {
 
             /* start of Y superblocks */
             right_edge = s->fragment_width;
             bottom_edge = s->fragment_height;

             current_width = -1;

             current_height = 0;

             superblock_row_inc = 3 * s->fragment_width -

                 (s->y_superblock_width * 4 - s->fragment_width);

 
             /* the first operation for this variable is to advance by 1 */
             current_fragment = -1;
 
         } else if (i == s->u_superblock_start) {
 
             /* start of U superblocks */
             right_edge = s->fragment_width / 2;
             bottom_edge = s->fragment_height / 2;

             current_width = -1;

             current_height = 0;

             superblock_row_inc = 3 * (s->fragment_width / 2) -

                 (s->c_superblock_width * 4 - s->fragment_width / 2);

 
             /* the first operation for this variable is to advance by 1 */

             current_fragment = s->fragment_start[1] - 1;

 
         } else if (i == s->v_superblock_start) {
 
             /* start of V superblocks */
             right_edge = s->fragment_width / 2;
             bottom_edge = s->fragment_height / 2;

             current_width = -1;

             current_height = 0;

             superblock_row_inc = 3 * (s->fragment_width / 2) -

                 (s->c_superblock_width * 4 - s->fragment_width / 2);

 
             /* the first operation for this variable is to advance by 1 */

             current_fragment = s->fragment_start[2] - 1;

 
         }
 

         if (current_width >= right_edge - 1) {

             /* reset width and move to next superblock row */

             current_width = -1;

             current_height += 4;
 
             /* fragment is now at the start of a new superblock row */
             current_fragment += superblock_row_inc;
         }
 
         /* iterate through all 16 fragments in a superblock */
         for (j = 0; j < 16; j++) {

             current_fragment += travel_width[j] + right_edge * travel_height[j];

             current_width += travel_width[j];

             current_height += travel_height[j];
 
             /* check if the fragment is in bounds */

             if ((current_width < right_edge) &&

                 (current_height < bottom_edge)) {
                 s->superblock_fragments[mapping_index] = current_fragment;
             } else {
                 s->superblock_fragments[mapping_index] = -1;
             }
 
             mapping_index++;
         }
     }
 
     /* initialize the superblock <-> macroblock mapping; iterate through
      * all of the Y plane superblocks to build this mapping */
     right_edge = s->macroblock_width;
     bottom_edge = s->macroblock_height;

     current_width = -1;

     current_height = 0;

     superblock_row_inc = s->macroblock_width -

         (s->y_superblock_width * 2 - s->macroblock_width);

     hilbert = hilbert_walk_mb;
     mapping_index = 0;
     current_macroblock = -1;
     for (i = 0; i < s->u_superblock_start; i++) {
 

         if (current_width >= right_edge - 1) {

             /* reset width and move to next superblock row */

             current_width = -1;

             current_height += 2;
 
             /* macroblock is now at the start of a new superblock row */
             current_macroblock += superblock_row_inc;
         }
 
         /* iterate through each potential macroblock in the superblock */
         for (j = 0; j < 4; j++) {
             current_macroblock += hilbert_walk_mb[j];

             current_width += travel_width_mb[j];

             current_height += travel_height_mb[j];
 
             /* check if the macroblock is in bounds */

             if ((current_width < right_edge) &&

                 (current_height < bottom_edge)) {
                 s->superblock_macroblocks[mapping_index] = current_macroblock;
             } else {
                 s->superblock_macroblocks[mapping_index] = -1;
             }
 
             mapping_index++;
         }
     }
 
     /* initialize the macroblock <-> fragment mapping */
     current_fragment = 0;
     current_macroblock = 0;
     mapping_index = 0;
     for (i = 0; i < s->fragment_height; i += 2) {
 
         for (j = 0; j < s->fragment_width; j += 2) {
 
             s->all_fragments[current_fragment].macroblock = current_macroblock;
             s->macroblock_fragments[mapping_index++] = current_fragment;
 
             if (j + 1 < s->fragment_width) {
                 s->all_fragments[current_fragment + 1].macroblock = current_macroblock;
                 s->macroblock_fragments[mapping_index++] = current_fragment + 1;
             } else
                 s->macroblock_fragments[mapping_index++] = -1;
 
             if (i + 1 < s->fragment_height) {

                 s->all_fragments[current_fragment + s->fragment_width].macroblock =

                     current_macroblock;

                 s->macroblock_fragments[mapping_index++] =

                     current_fragment + s->fragment_width;
             } else
                 s->macroblock_fragments[mapping_index++] = -1;
 
             if ((j + 1 < s->fragment_width) && (i + 1 < s->fragment_height)) {

                 s->all_fragments[current_fragment + s->fragment_width + 1].macroblock =

                     current_macroblock;

                 s->macroblock_fragments[mapping_index++] =

                     current_fragment + s->fragment_width + 1;
             } else
                 s->macroblock_fragments[mapping_index++] = -1;
 
             /* C planes */

             c_fragment = s->fragment_start[1] +

                 (i * s->fragment_width / 4) + (j / 2);

             s->all_fragments[c_fragment].macroblock = s->macroblock_count;

             s->macroblock_fragments[mapping_index++] = c_fragment;
 

             c_fragment = s->fragment_start[2] +

                 (i * s->fragment_width / 4) + (j / 2);

             s->all_fragments[c_fragment].macroblock = s->macroblock_count;

             s->macroblock_fragments[mapping_index++] = c_fragment;
 
             if (j + 2 <= s->fragment_width)
                 current_fragment += 2;

             else

                 current_fragment++;
             current_macroblock++;
         }
 
         current_fragment += s->fragment_width;
     }

 
     return 0;  /* successful path out */

 }
 
 /*
  * This function wipes out all of the fragment data.
  */
 static void init_frame(Vp3DecodeContext *s, GetBitContext *gb)
 {
     int i;
 
     /* zero out all of the fragment information */
     s->coded_fragment_list_index = 0;
     for (i = 0; i < s->fragment_count; i++) {

         s->coeff_counts[i] = 0;

         s->all_fragments[i].motion_x = 127;
         s->all_fragments[i].motion_y = 127;
         s->all_fragments[i].next_coeff= NULL;

         s->coeffs[i].index=
         s->coeffs[i].coeff=0;
         s->coeffs[i].next= NULL;

     }
 }
 
 /*

  * This function sets up the dequantization tables used for a particular

  * frame.
  */
 static void init_dequantizer(Vp3DecodeContext *s)
 {

     int ac_scale_factor = s->coded_ac_scale_factor[s->quality_index];

     int dc_scale_factor = s->coded_dc_scale_factor[s->quality_index];

     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->quality_index <= 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->quality_index)*s->base_matrix[bmi][i]
                             - 2*(qistart-s->quality_index)*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[inter][plane][s->dsp.idct_permutation[i]]= av_clip((qscale * coeff)/100 * 4, qmin, 4096);

             }
         }

     }

     memset(s->qscale_table, (FFMAX(s->qmat[0][0][1], s->qmat[0][1][1])+8)/16, 512); //FIXME finetune

 }
 
 /*

  * This function initializes the loop filter boundary limits if the frame's
  * quality index is different from the previous frame's.
  */
 static void init_loop_filter(Vp3DecodeContext *s)
 {
     int *bounding_values= s->bounding_values_array+127;
     int filter_limit;
     int x;
 
     filter_limit = s->filter_limit_values[s->quality_index];
 
     /* set up the bounding values */
     memset(s->bounding_values_array, 0, 256 * sizeof(int));
     for (x = 0; x < filter_limit; x++) {
         bounding_values[-x - filter_limit] = -filter_limit + x;
         bounding_values[-x] = -x;
         bounding_values[x] = x;
         bounding_values[x + filter_limit] = filter_limit - x;
     }

     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 bit = 0;
     int current_superblock = 0;
     int current_run = 0;
     int decode_fully_flags = 0;
     int decode_partial_blocks = 0;

     int first_c_fragment_seen;

 
     int i, j;
     int current_fragment;
 
     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);

         /* toggle the bit because as soon as the first run length is

          * fetched the bit will be toggled again */
         bit ^= 1;
         while (current_superblock < s->superblock_count) {

             if (current_run-- == 0) {

                 bit ^= 1;

                 current_run = get_vlc2(gb,

                     s->superblock_run_length_vlc.table, 6, 2);
                 if (current_run == 33)

                     current_run += get_bits(gb, 12);

 
                 /* if any of the superblocks are not partially coded, flag
                  * a boolean to decode the list of fully-coded superblocks */

                 if (bit == 0) {

                     decode_fully_flags = 1;

                 } else {

                     /* make a note of the fact that there are partially coded
                      * superblocks */
                     decode_partial_blocks = 1;
                 }

             }

             s->superblock_coding[current_superblock++] = bit;

         }
 
         /* unpack the list of fully coded superblocks if any of the blocks were
          * not marked as partially coded in the previous step */
         if (decode_fully_flags) {
 
             current_superblock = 0;
             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;
             while (current_superblock < s->superblock_count) {
 
                 /* skip any superblocks already marked as partially coded */
                 if (s->superblock_coding[current_superblock] == SB_NOT_CODED) {
 

                     if (current_run-- == 0) {

                         bit ^= 1;

                         current_run = get_vlc2(gb,

                             s->superblock_run_length_vlc.table, 6, 2);
                         if (current_run == 33)

                             current_run += get_bits(gb, 12);

                     }

                     s->superblock_coding[current_superblock] = 2*bit;

                 }
                 current_superblock++;
             }
         }
 
         /* if there were partial blocks, initialize bitstream for
          * unpacking fragment codings */
         if (decode_partial_blocks) {
 
             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->coded_fragment_list_index = 0;

     s->next_coeff= s->coeffs + s->fragment_count;

     s->first_coded_y_fragment = s->first_coded_c_fragment = 0;
     s->last_coded_y_fragment = s->last_coded_c_fragment = -1;

     first_c_fragment_seen = 0;

     memset(s->macroblock_coding, MODE_COPY, s->macroblock_count);

     for (i = 0; i < s->superblock_count; 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 >= s->fragment_count) {

                 av_log(s->avctx, AV_LOG_ERROR, "  vp3:unpack_superblocks(): bad fragment number (%d >= %d)\n",

                     current_fragment, s->fragment_count);
                 return 1;
             }

             if (current_fragment != -1) {
                 if (s->superblock_coding[i] == SB_NOT_CODED) {
 
                     /* copy all the fragments from the prior frame */

                     s->all_fragments[current_fragment].coding_method =

                         MODE_COPY;
 
                 } else 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);

                     }
 
                     if (bit) {

                         /* default mode; actual mode will be decoded in

                          * the next phase */

                         s->all_fragments[current_fragment].coding_method =

                             MODE_INTER_NO_MV;

                         s->all_fragments[current_fragment].next_coeff= s->coeffs + current_fragment;

                         s->coded_fragment_list[s->coded_fragment_list_index] =

                             current_fragment;

                         if ((current_fragment >= s->fragment_start[1]) &&

                             (s->last_coded_y_fragment == -1) &&
                             (!first_c_fragment_seen)) {

                             s->first_coded_c_fragment = s->coded_fragment_list_index;
                             s->last_coded_y_fragment = s->first_coded_c_fragment - 1;

                             first_c_fragment_seen = 1;

                         }
                         s->coded_fragment_list_index++;

                         s->macroblock_coding[s->all_fragments[current_fragment].macroblock] = MODE_INTER_NO_MV;

                     } else {
                         /* not coded; copy this fragment from the prior frame */
                         s->all_fragments[current_fragment].coding_method =
                             MODE_COPY;
                     }
 
                 } else {
 
                     /* fragments are fully coded in this superblock; actual
                      * coding will be determined in next step */

                     s->all_fragments[current_fragment].coding_method =

                         MODE_INTER_NO_MV;

                     s->all_fragments[current_fragment].next_coeff= s->coeffs + current_fragment;

                     s->coded_fragment_list[s->coded_fragment_list_index] =

                         current_fragment;

                     if ((current_fragment >= s->fragment_start[1]) &&

                         (s->last_coded_y_fragment == -1) &&
                         (!first_c_fragment_seen)) {

                         s->first_coded_c_fragment = s->coded_fragment_list_index;
                         s->last_coded_y_fragment = s->first_coded_c_fragment - 1;

                         first_c_fragment_seen = 1;

                     }
                     s->coded_fragment_list_index++;

                     s->macroblock_coding[s->all_fragments[current_fragment].macroblock] = MODE_INTER_NO_MV;

                 }
             }
         }
     }

     if (!first_c_fragment_seen)
         /* only Y fragments coded in this frame */

         s->last_coded_y_fragment = s->coded_fragment_list_index - 1;

     else

         /* end the list of coded C fragments */

         s->last_coded_c_fragment = s->coded_fragment_list_index - 1;

     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;
     int scheme;
     int current_macroblock;
     int current_fragment;
     int coding_mode;

     int custom_mode_alphabet[CODING_MODE_COUNT];

 
     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;

         }
 
         /* iterate through all of the macroblocks that contain 1 or more
          * coded fragments */
         for (i = 0; i < s->u_superblock_start; i++) {
 
             for (j = 0; j < 4; j++) {
                 current_macroblock = s->superblock_macroblocks[i * 4 + j];
                 if ((current_macroblock == -1) ||

                     (s->macroblock_coding[current_macroblock] == MODE_COPY))

                     continue;

                 if (current_macroblock >= s->macroblock_count) {

                     av_log(s->avctx, AV_LOG_ERROR, "  vp3:unpack_modes(): bad macroblock number (%d >= %d)\n",

                         current_macroblock, s->macroblock_count);
                     return 1;
                 }

 
                 /* mode 7 means get 3 bits for each coding mode */
                 if (scheme == 7)
                     coding_mode = get_bits(gb, 3);

                 else if(scheme == 0)
                     coding_mode = custom_mode_alphabet
                         [get_vlc2(gb, s->mode_code_vlc.table, 3, 3)];

                 else

                     coding_mode = ModeAlphabet[scheme-1]

                         [get_vlc2(gb, s->mode_code_vlc.table, 3, 3)];

                 s->macroblock_coding[current_macroblock] = coding_mode;

                 for (k = 0; k < 6; k++) {

                     current_fragment =

                         s->macroblock_fragments[current_macroblock * 6 + k];

                     if (current_fragment == -1)
                         continue;
                     if (current_fragment >= s->fragment_count) {

                         av_log(s->avctx, AV_LOG_ERROR, "  vp3:unpack_modes(): bad fragment number (%d >= %d)\n",

                             current_fragment, s->fragment_count);
                         return 1;
                     }

                     if (s->all_fragments[current_fragment].coding_method !=

                         MODE_COPY)
                         s->all_fragments[current_fragment].coding_method =
                             coding_mode;
                 }
             }
         }
     }

 
     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 i, j, k, l;

     int coding_mode;
     int motion_x[6];
     int motion_y[6];
     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;
 

     if (s->keyframe)

         return 0;

     memset(motion_x, 0, 6 * sizeof(int));
     memset(motion_y, 0, 6 * sizeof(int));

     /* 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 (i = 0; i < s->u_superblock_start; i++) {

         for (j = 0; j < 4; j++) {
             current_macroblock = s->superblock_macroblocks[i * 4 + j];
             if ((current_macroblock == -1) ||
                 (s->macroblock_coding[current_macroblock] == MODE_COPY))
                 continue;
             if (current_macroblock >= s->macroblock_count) {
                 av_log(s->avctx, AV_LOG_ERROR, "  vp3:unpack_vectors(): bad macroblock number (%d >= %d)\n",
                     current_macroblock, s->macroblock_count);
                 return 1;
             }

             current_fragment = s->macroblock_fragments[current_macroblock * 6];
             if (current_fragment >= s->fragment_count) {
                 av_log(s->avctx, AV_LOG_ERROR, "  vp3:unpack_vectors(): bad fragment number (%d >= %d\n",
                     current_fragment, s->fragment_count);
                 return 1;
             }
             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)];

                 }

                 for (k = 1; k < 6; k++) {
                     motion_x[k] = motion_x[0];
                     motion_y[k] = motion_y[0];
                 }

                 /* 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 */
                 motion_x[4] = motion_y[4] = 0;
                 for (k = 0; k < 4; k++) {
                     for (l = 0; l < s->coded_fragment_list_index; l++)
                         if (s->coded_fragment_list[l] == s->macroblock_fragments[6*current_macroblock + k])
                             break;
                     if (l < s->coded_fragment_list_index) {
                         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;

                     }

                     motion_x[4] += motion_x[k];
                     motion_y[4] += motion_y[k];
                 }

                 motion_x[5]=
                 motion_x[4]= RSHIFT(motion_x[4], 2);
                 motion_y[5]=
                 motion_y[4]= RSHIFT(motion_y[4], 2);
                 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;
                 for (k = 1; k < 6; k++) {
                     motion_x[k] = motion_x[0];
                     motion_y[k] = motion_y[0];
                 }

                 /* 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;
                 for (k = 1; k < 6; k++) {
                     motion_x[k] = motion_x[0];
                     motion_y[k] = motion_y[0];
                 }

                 /* 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 */
                 memset(motion_x, 0, 6 * sizeof(int));
                 memset(motion_y, 0, 6 * sizeof(int));

                 /* no vector maintenance */
                 break;
             }

             /* assign the motion vectors to the correct fragments */
             for (k = 0; k < 6; k++) {
                 current_fragment =
                     s->macroblock_fragments[current_macroblock * 6 + k];
                 if (current_fragment == -1)
                     continue;
                 if (current_fragment >= s->fragment_count) {
                     av_log(s->avctx, AV_LOG_ERROR, "  vp3:unpack_vectors(): bad fragment number (%d >= %d)\n",
                         current_fragment, s->fragment_count);
                     return 1;

                 }

                 s->all_fragments[current_fragment].motion_x = motion_x[k];
                 s->all_fragments[current_fragment].motion_y = motion_y[k];

             }
         }

     }

 
     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 first_fragment, int last_fragment,
                         int eob_run)
 {
     int i;
     int token;

     int zero_run = 0;
     DCTELEM coeff = 0;

     Vp3Fragment *fragment;

     uint8_t *perm= s->scantable.permutated;

     int bits_to_get;

     if ((first_fragment >= s->fragment_count) ||

         (last_fragment >= s->fragment_count)) {
 

         av_log(s->avctx, AV_LOG_ERROR, "  vp3:unpack_vlcs(): bad fragment number (%d -> %d ?)\n",

             first_fragment, last_fragment);

         return 0;

     }
 

     for (i = first_fragment; i <= last_fragment; i++) {

         int fragment_num = s->coded_fragment_list[i];

         if (s->coeff_counts[fragment_num] > coeff_index)

             continue;

         fragment = &s->all_fragments[fragment_num];

 
         if (!eob_run) {
             /* decode a VLC into a token */
             token = get_vlc2(gb, table->table, 5, 3);
             /* use the token to get a zero run, a coefficient, and an eob run */

             if (token <= 6) {
                 eob_run = eob_run_base[token];
                 if (eob_run_get_bits[token])
                     eob_run += get_bits(gb, eob_run_get_bits[token]);
                 coeff = zero_run = 0;
             } else {
                 bits_to_get = coeff_get_bits[token];
                 if (!bits_to_get)
                     coeff = coeff_tables[token][0];
                 else
                     coeff = coeff_tables[token][get_bits(gb, 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 (!eob_run) {

             s->coeff_counts[fragment_num] += zero_run;
             if (s->coeff_counts[fragment_num] < 64){

                 fragment->next_coeff->coeff= coeff;

                 fragment->next_coeff->index= perm[s->coeff_counts[fragment_num]++]; //FIXME perm here already?

                 fragment->next_coeff->next= s->next_coeff;
                 s->next_coeff->next=NULL;
                 fragment->next_coeff= s->next_coeff++;
             }

         } else {

             s->coeff_counts[fragment_num] |= 128;

             eob_run--;
         }
     }
 
     return eob_run;
 }
 
 /*
  * 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;
 

     /* 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,

         s->first_coded_y_fragment, s->last_coded_y_fragment, residual_eob_run);

 
     /* unpack the C plane DC coefficients */
     residual_eob_run = unpack_vlcs(s, gb, &s->dc_vlc[dc_c_table], 0,

         s->first_coded_c_fragment, s->last_coded_c_fragment, residual_eob_run);

     /* fetch the AC table indexes */

     ac_y_table = get_bits(gb, 4);
     ac_c_table = get_bits(gb, 4);
 

     /* unpack the group 1 AC coefficients (coeffs 1-5) */

     for (i = 1; i <= 5; i++) {

         residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_1[ac_y_table], i,

             s->first_coded_y_fragment, s->last_coded_y_fragment, residual_eob_run);

         residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_1[ac_c_table], i,

             s->first_coded_c_fragment, s->last_coded_c_fragment, residual_eob_run);

     }
 

     /* unpack the group 2 AC coefficients (coeffs 6-14) */

     for (i = 6; i <= 14; i++) {

         residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_2[ac_y_table], i,

             s->first_coded_y_fragment, s->last_coded_y_fragment, residual_eob_run);

         residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_2[ac_c_table], i,

             s->first_coded_c_fragment, s->last_coded_c_fragment, residual_eob_run);

     }
 

     /* unpack the group 3 AC coefficients (coeffs 15-27) */

     for (i = 15; i <= 27; i++) {

         residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_3[ac_y_table], i,

             s->first_coded_y_fragment, s->last_coded_y_fragment, residual_eob_run);

         residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_3[ac_c_table], i,

             s->first_coded_c_fragment, s->last_coded_c_fragment, residual_eob_run);

     }
 

     /* unpack the group 4 AC coefficients (coeffs 28-63) */

     for (i = 28; i <= 63; i++) {

         residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_4[ac_y_table], i,

             s->first_coded_y_fragment, s->last_coded_y_fragment, residual_eob_run);

         residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_4[ac_c_table], i,

             s->first_coded_c_fragment, s->last_coded_c_fragment, 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 FRAME_CODED(x) (s->all_fragments[x].coding_method != MODE_COPY)

 #define DC_COEFF(u) (s->coeffs[u].index ? 0 : s->coeffs[u].coeff) //FIXME do somethin to simplify this

 
 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
      */

     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. */
     unsigned char compatible_frame[8] = {
         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 */
     };
     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(FRAME_CODED(l) && COMPATIBLE_FRAME(l))
                         transform |= PL;

                 }
                 if(y){
                     u= i-fragment_width;

                     vu = DC_COEFF(u);

                     if(FRAME_CODED(u) && COMPATIBLE_FRAME(u))
                         transform |= PU;

                     if(x){
                         ul= i-fragment_width-1;
                         vul = DC_COEFF(ul);

                         if(FRAME_CODED(ul) && COMPATIBLE_FRAME(ul))
                             transform |= PUL;

                     }
                     if(x + 1 < fragment_width){
                         ur= i-fragment_width+1;
                         vur = DC_COEFF(ur);

                         if(FRAME_CODED(ur) && 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 == 13) || (transform == 15)) {

                         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 */
                 if(s->coeffs[i].index){
                     *s->next_coeff= s->coeffs[i];
                     s->coeffs[i].index=0;
                     s->coeffs[i].coeff=0;
                     s->coeffs[i].next= s->next_coeff++;
                 }
                 s->coeffs[i].coeff += predicted_dc;

                 /* save the DC */

                 last_dc[current_frame_type] = DC_COEFF(i);

                 if(DC_COEFF(i) && !(s->coeff_counts[i]&127)){
                     s->coeff_counts[i]= 129;

 //                    s->all_fragments[i].next_coeff= s->next_coeff;
                     s->coeffs[i].next= s->next_coeff;
                     (s->next_coeff++)->next=NULL;
                 }

             }
         }
     }
 }
 
 /*

  * Perform the final rendering for a particular slice of data.
  * The slice number ranges from 0..(macroblock_height - 1).
  */
 static void render_slice(Vp3DecodeContext *s, int slice)
 {

     int x;

     int16_t *dequantizer;

     DECLARE_ALIGNED_16(DCTELEM, block[64]);

     int motion_x = 0xdeadbeef, motion_y = 0xdeadbeef;
     int motion_halfpel_index;
     uint8_t *motion_source;
     int plane;
     int current_macroblock_entry = slice * s->macroblock_width * 6;
 
     if (slice >= s->macroblock_height)
         return;
 
     for (plane = 0; plane < 3; plane++) {

         uint8_t *output_plane = s->current_frame.data    [plane];
         uint8_t *  last_plane = s->   last_frame.data    [plane];
         uint8_t *golden_plane = s-> golden_frame.data    [plane];
         int stride            = s->current_frame.linesize[plane];
         int plane_width       = s->width  >> !!plane;
         int plane_height      = s->height >> !!plane;
         int y =        slice *  FRAGMENT_PIXELS << !plane ;
         int slice_height = y + (FRAGMENT_PIXELS << !plane);
         int i = s->macroblock_fragments[current_macroblock_entry + plane + 3*!!plane];
 
         if (!s->flipped_image) stride = -stride;

         if(FFABS(stride) > 2048)

             return; //various tables are fixed size
 
         /* for each fragment row in the slice (both of them)... */
         for (; y < slice_height; y += 8) {
 
             /* for each fragment in a row... */
             for (x = 0; x < plane_width; x += 8, i++) {
 
                 if ((i < 0) || (i >= s->fragment_count)) {
                     av_log(s->avctx, AV_LOG_ERROR, "  vp3:render_slice(): bad fragment number (%d)\n", i);
                     return;
                 }
 
                 /* transform if this block was coded */
                 if ((s->all_fragments[i].coding_method != MODE_COPY) &&
                     !((s->avctx->flags & CODEC_FLAG_GRAY) && plane)) {
 
                     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 += s->all_fragments[i].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 = s->all_fragments[i].motion_x;
                         motion_y = s->all_fragments[i].motion_y;
                         if(plane){
                             motion_x= (motion_x>>1) | (motion_x&1);
                             motion_y= (motion_y>>1) | (motion_y&1);
                         }
 
                         src_x= (motion_x>>1) + x;
                         src_y= (motion_y>>1) + y;
                         if ((motion_x == 127) || (motion_y == 127))
                             av_log(s->avctx, AV_LOG_ERROR, " help! got invalid motion vector! (%X, %X)\n", motion_x, motion_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 -= 9*stride;
                             else temp += 9*stride;
 
                             ff_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 + s->all_fragments[i].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 + s->all_fragments[i].first_pixel,

                                 motion_source - d,
                                 motion_source + stride + 1 + d,

                                 stride, 8);
                         }

                         dequantizer = s->qmat[1][plane];

                     }else{

                         dequantizer = s->qmat[0][plane];

                     }
 
                     /* dequantize the DCT coefficients */
                     if(s->avctx->idct_algo==FF_IDCT_VP3){
                         Coeff *coeff= s->coeffs + i;

                         s->dsp.clear_block(block);

                         while(coeff->next){
                             block[coeff->index]= coeff->coeff * dequantizer[coeff->index];
                             coeff= coeff->next;
                         }
                     }else{
                         Coeff *coeff= s->coeffs + i;

                         s->dsp.clear_block(block);

                         while(coeff->next){
                             block[coeff->index]= (coeff->coeff * dequantizer[coeff->index] + 2)>>2;
                             coeff= coeff->next;
                         }
                     }
 
                     /* invert DCT and place (or add) in final output */

                     if (s->all_fragments[i].coding_method == MODE_INTRA) {
                         if(s->avctx->idct_algo!=FF_IDCT_VP3)
                             block[0] += 128<<3;
                         s->dsp.idct_put(
                             output_plane + s->all_fragments[i].first_pixel,
                             stride,
                             block);
                     } else {
                         s->dsp.idct_add(
                             output_plane + s->all_fragments[i].first_pixel,
                             stride,
                             block);
                     }
                 } else {
 
                     /* copy directly from the previous frame */
                     s->dsp.put_pixels_tab[1][0](
                         output_plane + s->all_fragments[i].first_pixel,
                         last_plane + s->all_fragments[i].first_pixel,
                         stride, 8);
 
                 }

 #if 0

                 /* perform the left edge filter if:
                  *   - the fragment is not on the left column
                  *   - the fragment is coded in this frame
                  *   - the fragment is not coded in this frame but the left
                  *     fragment is coded in this frame (this is done instead
                  *     of a right edge filter when rendering the left fragment
                  *     since this fragment is not available yet) */

                 if ((x > 0) &&

                     ((s->all_fragments[i].coding_method != MODE_COPY) ||
                      ((s->all_fragments[i].coding_method == MODE_COPY) &&
                       (s->all_fragments[i - 1].coding_method != MODE_COPY)) )) {

                     horizontal_filter(

                         output_plane + s->all_fragments[i].first_pixel + 7*stride,

                         -stride, s->bounding_values_array + 127);

                 }
 

                 /* perform the top edge filter if:
                  *   - the fragment is not on the top row
                  *   - the fragment is coded in this frame
                  *   - the fragment is not coded in this frame but the above
                  *     fragment is coded in this frame (this is done instead
                  *     of a bottom edge filter when rendering the above
                  *     fragment since this fragment is not available yet) */

                 if ((y > 0) &&

                     ((s->all_fragments[i].coding_method != MODE_COPY) ||
                      ((s->all_fragments[i].coding_method == MODE_COPY) &&
                       (s->all_fragments[i - fragment_width].coding_method != MODE_COPY)) )) {

                     vertical_filter(

                         output_plane + s->all_fragments[i].first_pixel - stride,

                         -stride, s->bounding_values_array + 127);

                 }

 #endif

             }
         }
     }
 
      /* 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);

       */
 
     emms_c();
 }
 

 static void apply_loop_filter(Vp3DecodeContext *s)
 {

     int plane;
     int x, y;

     int *bounding_values= s->bounding_values_array+127;

 #if 0

     int bounding_values_array[256];

     int filter_limit;
 
     /* find the right loop limit value */
     for (x = 63; x >= 0; x--) {
         if (vp31_ac_scale_factor[x] >= s->quality_index)
             break;
     }

     filter_limit = vp31_filter_limit_values[s->quality_index];

 
     /* set up the bounding values */

     memset(bounding_values_array, 0, 256 * sizeof(int));

     for (x = 0; x < filter_limit; x++) {
         bounding_values[-x - filter_limit] = -filter_limit + x;
         bounding_values[-x] = -x;
         bounding_values[x] = x;
         bounding_values[x + filter_limit] = filter_limit - x;
     }

 #endif

 
     for (plane = 0; plane < 3; plane++) {

         int width           = s->fragment_width  >> !!plane;
         int height          = s->fragment_height >> !!plane;
         int fragment        = s->fragment_start        [plane];
         int stride          = s->current_frame.linesize[plane];
         uint8_t *plane_data = s->current_frame.data    [plane];

         if (!s->flipped_image) stride = -stride;

 
         for (y = 0; y < height; y++) {

             for (x = 0; x < width; x++) {
                 /* do not perform left edge filter for left columns frags */
                 if ((x > 0) &&
                     (s->all_fragments[fragment].coding_method != MODE_COPY)) {

                     s->dsp.vp3_h_loop_filter(

                         plane_data + s->all_fragments[fragment].first_pixel,

                         stride, bounding_values);
                 }
 
                 /* do not perform top edge filter for top row fragments */
                 if ((y > 0) &&
                     (s->all_fragments[fragment].coding_method != MODE_COPY)) {

                     s->dsp.vp3_v_loop_filter(

                         plane_data + s->all_fragments[fragment].first_pixel,

                         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].coding_method != MODE_COPY) &&
                     (s->all_fragments[fragment + 1].coding_method == MODE_COPY)) {

                     s->dsp.vp3_h_loop_filter(

                         plane_data + s->all_fragments[fragment + 1].first_pixel,

                         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].coding_method != MODE_COPY) &&
                     (s->all_fragments[fragment + width].coding_method == MODE_COPY)) {

                     s->dsp.vp3_v_loop_filter(

                         plane_data + s->all_fragments[fragment + width].first_pixel,

                         stride, bounding_values);
                 }
 
                 fragment++;
             }
         }
     }

 }
 

 /*

  * This function computes the first pixel addresses for each fragment.
  * This function needs to be invoked after the first frame is allocated
  * so that it has access to the plane strides.
  */

 static void vp3_calculate_pixel_addresses(Vp3DecodeContext *s)

 {

 #define Y_INITIAL(chroma_shift)  s->flipped_image ? 1  : s->fragment_height >> chroma_shift
 #define Y_FINISHED(chroma_shift) s->flipped_image ? y <= s->fragment_height >> chroma_shift : y > 0

 
     int i, x, y;

     const int y_inc = s->flipped_image ? 1 : -1;

 
     /* figure out the first pixel addresses for each of the fragments */
     /* Y plane */
     i = 0;

     for (y = Y_INITIAL(0); Y_FINISHED(0); y += y_inc) {

         for (x = 0; x < s->fragment_width; x++) {

             s->all_fragments[i++].first_pixel =

                 s->golden_frame.linesize[0] * y * FRAGMENT_PIXELS -
                     s->golden_frame.linesize[0] +
                     x * FRAGMENT_PIXELS;
         }
     }
 
     /* U plane */

     i = s->fragment_start[1];

     for (y = Y_INITIAL(1); Y_FINISHED(1); y += y_inc) {

         for (x = 0; x < s->fragment_width / 2; x++) {

             s->all_fragments[i++].first_pixel =

                 s->golden_frame.linesize[1] * y * FRAGMENT_PIXELS -
                     s->golden_frame.linesize[1] +
                     x * FRAGMENT_PIXELS;
         }
     }
 
     /* V plane */

     i = s->fragment_start[2];

     for (y = Y_INITIAL(1); Y_FINISHED(1); y += y_inc) {

         for (x = 0; x < s->fragment_width / 2; x++) {

             s->all_fragments[i++].first_pixel =

                 s->golden_frame.linesize[2] * y * FRAGMENT_PIXELS -
                     s->golden_frame.linesize[2] +
                     x * FRAGMENT_PIXELS;
         }
     }
 }
 

 /*
  * This is the ffmpeg/libavcodec API init function.
  */

 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_superblock_count;
     int c_superblock_count;

     if (avctx->codec_tag == MKTAG('V','P','3','0'))

         s->version = 0;

     else

         s->version = 1;

     s->avctx = avctx;

     s->width = (avctx->width + 15) & 0xFFFFFFF0;
     s->height = (avctx->height + 15) & 0xFFFFFFF0;

     avctx->pix_fmt = PIX_FMT_YUV420P;

     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 */
     s->quality_index = -1;
 

     s->y_superblock_width = (s->width + 31) / 32;
     s->y_superblock_height = (s->height + 31) / 32;
     y_superblock_count = s->y_superblock_width * s->y_superblock_height;
 
     /* work out the dimensions for the C planes */
     c_width = s->width / 2;
     c_height = s->height / 2;
     s->c_superblock_width = (c_width + 31) / 32;
     s->c_superblock_height = (c_height + 31) / 32;
     c_superblock_count = s->c_superblock_width * s->c_superblock_height;
 
     s->superblock_count = y_superblock_count + (c_superblock_count * 2);
     s->u_superblock_start = y_superblock_count;
     s->v_superblock_start = s->u_superblock_start + c_superblock_count;

     s->superblock_coding = av_malloc(s->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 = s->width / FRAGMENT_PIXELS;
     s->fragment_height = s->height / FRAGMENT_PIXELS;
 
     /* fragment count covers all 8x8 blocks for all 3 planes */
     s->fragment_count = s->fragment_width * s->fragment_height * 3 / 2;

     s->fragment_start[1] = s->fragment_width * s->fragment_height;
     s->fragment_start[2] = s->fragment_width * s->fragment_height * 5 / 4;

 
     s->all_fragments = av_malloc(s->fragment_count * sizeof(Vp3Fragment));

     s->coeff_counts = av_malloc(s->fragment_count * sizeof(*s->coeff_counts));

     s->coeffs = av_malloc(s->fragment_count * sizeof(Coeff) * 65);

     s->coded_fragment_list = av_malloc(s->fragment_count * sizeof(int));

     s->pixel_addresses_initialized = 0;

     if (!s->superblock_coding || !s->all_fragments || !s->coeff_counts ||
         !s->coeffs || !s->coded_fragment_list) {
         vp3_decode_end(avctx);
         return -1;
     }

     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], 5, 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], 5, 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], 5, 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], 5, 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], 5, 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], 5, 32,

                 &s->huffman_table[i][0][1], 4, 2,

                 &s->huffman_table[i][0][0], 4, 2, 0) < 0)
                 goto vlc_fail;

 
             /* group 1 AC histograms */

             if (init_vlc(&s->ac_vlc_1[i], 5, 32,

                 &s->huffman_table[i+16][0][1], 4, 2,

                 &s->huffman_table[i+16][0][0], 4, 2, 0) < 0)
                 goto vlc_fail;

 
             /* group 2 AC histograms */

             if (init_vlc(&s->ac_vlc_2[i], 5, 32,

                 &s->huffman_table[i+16*2][0][1], 4, 2,

                 &s->huffman_table[i+16*2][0][0], 4, 2, 0) < 0)
                 goto vlc_fail;

 
             /* group 3 AC histograms */

             if (init_vlc(&s->ac_vlc_3[i], 5, 32,

                 &s->huffman_table[i+16*3][0][1], 4, 2,

                 &s->huffman_table[i+16*3][0][0], 4, 2, 0) < 0)
                 goto vlc_fail;

 
             /* group 4 AC histograms */

             if (init_vlc(&s->ac_vlc_4[i], 5, 32,

                 &s->huffman_table[i+16*4][0][1], 4, 2,

                 &s->huffman_table[i+16*4][0][0], 4, 2, 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);
 

     /* work out the block mapping tables */
     s->superblock_fragments = av_malloc(s->superblock_count * 16 * sizeof(int));
     s->superblock_macroblocks = av_malloc(s->superblock_count * 4 * sizeof(int));
     s->macroblock_fragments = av_malloc(s->macroblock_count * 6 * sizeof(int));

     s->macroblock_coding = av_malloc(s->macroblock_count + 1);

     if (!s->superblock_fragments || !s->superblock_macroblocks ||
         !s->macroblock_fragments || !s->macroblock_coding) {
         vp3_decode_end(avctx);
         return -1;
     }

     init_block_mapping(s);
 

     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 0;

 
 vlc_fail:
     av_log(avctx, AV_LOG_FATAL, "Invalid huffman table\n");
     return -1;

 }
 
 /*
  * This is the ffmpeg/libavcodec API frame decode function.
  */

 static int vp3_decode_frame(AVCodecContext *avctx,

                             void *data, int *data_size,

                             const uint8_t *buf, int buf_size)

 {
     Vp3DecodeContext *s = avctx->priv_data;
     GetBitContext gb;
     static int counter = 0;

     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);

     s->last_quality_index = s->quality_index;

 
     s->nqis=0;
     do{
         s->qis[s->nqis++]= get_bits(&gb, 6);
     } while(s->theora >= 0x030200 && s->nqis<3 && get_bits1(&gb));
 
     s->quality_index= s->qis[0];

     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":"", counter, s->quality_index);

     counter++;
 

     if (s->quality_index != s->last_quality_index) {

         init_dequantizer(s);

         init_loop_filter(s);
     }

     if (avctx->skip_frame >= AVDISCARD_NONKEY && !s->keyframe)
         return buf_size;
 

     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 (counter == 1)
                     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? */
         }

         if (s->last_frame.data[0] == s->golden_frame.data[0]) {
             if (s->golden_frame.data[0])
                 avctx->release_buffer(avctx, &s->golden_frame);

             s->last_frame= s->golden_frame; /* ensure that we catch any access to this released frame */

         } else {
             if (s->golden_frame.data[0])
                 avctx->release_buffer(avctx, &s->golden_frame);
             if (s->last_frame.data[0])
                 avctx->release_buffer(avctx, &s->last_frame);
         }

         s->golden_frame.reference = 3;

         if(avctx->get_buffer(avctx, &s->golden_frame) < 0) {

             av_log(s->avctx, AV_LOG_ERROR, "vp3: get_buffer() failed\n");

             return -1;
         }
 
         /* golden frame is also the current frame */

         s->current_frame= s->golden_frame;

 
         /* time to figure out pixel addresses? */

         if (!s->pixel_addresses_initialized)

         {

             vp3_calculate_pixel_addresses(s);

             s->pixel_addresses_initialized = 1;

         }

     } else {
         /* allocate a new current frame */

         s->current_frame.reference = 3;

         if (!s->pixel_addresses_initialized) {

             av_log(s->avctx, AV_LOG_ERROR, "vp3: first frame not a keyframe\n");
             return -1;
         }

         if(avctx->get_buffer(avctx, &s->current_frame) < 0) {

             av_log(s->avctx, AV_LOG_ERROR, "vp3: get_buffer() failed\n");

             return -1;
         }
     }
 

     s->current_frame.qscale_table= s->qscale_table; //FIXME allocate individual tables per AVFrame
     s->current_frame.qstride= 0;
 

     init_frame(s, &gb);
 

     if (unpack_superblocks(s, &gb)){
         av_log(s->avctx, AV_LOG_ERROR, "error in unpack_superblocks\n");
         return -1;
     }
     if (unpack_modes(s, &gb)){
         av_log(s->avctx, AV_LOG_ERROR, "error in unpack_modes\n");
         return -1;
     }
     if (unpack_vectors(s, &gb)){
         av_log(s->avctx, AV_LOG_ERROR, "error in unpack_vectors\n");
         return -1;
     }
     if (unpack_dct_coeffs(s, &gb)){
         av_log(s->avctx, AV_LOG_ERROR, "error in unpack_dct_coeffs\n");

         return -1;
     }

 
     reverse_dc_prediction(s, 0, s->fragment_width, s->fragment_height);

     if ((avctx->flags & CODEC_FLAG_GRAY) == 0) {

         reverse_dc_prediction(s, s->fragment_start[1],

             s->fragment_width / 2, s->fragment_height / 2);

         reverse_dc_prediction(s, s->fragment_start[2],

             s->fragment_width / 2, s->fragment_height / 2);

     }
 
     for (i = 0; i < s->macroblock_height; i++)
         render_slice(s, i);

     apply_loop_filter(s);

     *data_size=sizeof(AVFrame);
     *(AVFrame*)data= s->current_frame;
 

     /* 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.data[0] != s->golden_frame.data[0]))
         avctx->release_buffer(avctx, &s->last_frame);

     /* shuffle frames (last = current) */

     s->last_frame= s->current_frame;

     s->current_frame.data[0]= NULL; /* ensure that we catch any access to this released frame */

 
     return buf_size;
 }
 
 /*
  * This is the ffmpeg/libavcodec API module cleanup function.
  */

 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->coeff_counts);

     av_free(s->coeffs);

     av_free(s->coded_fragment_list);
     av_free(s->superblock_fragments);
     av_free(s->superblock_macroblocks);
     av_free(s->macroblock_fragments);

     av_free(s->macroblock_coding);

     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 */

     if (s->golden_frame.data[0] && s->golden_frame.data[0] != s->last_frame.data[0])

         avctx->release_buffer(avctx, &s->golden_frame);
     if (s->last_frame.data[0])
         avctx->release_buffer(avctx, &s->last_frame);
     /* no need to release the current_frame since it will always be pointing
      * to the same frame as either the golden or last frame */

 
     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 int theora_decode_header(AVCodecContext *avctx, GetBitContext *gb)

 {
     Vp3DecodeContext *s = avctx->priv_data;

     int visible_width, visible_height;

     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(avcodec_check_dimensions(avctx, s->width, s->height)){

         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 >= 0x030400)
     {

         skip_bits(gb, 32); /* total number of superblocks in a frame */

         // fixme, the next field is 36bits long

         skip_bits(gb, 32); /* total number of blocks in a frame */
         skip_bits(gb, 4); /* total number of blocks in a frame */
         skip_bits(gb, 32); /* total number of macroblocks in a frame */

     }

     if (s->theora >= 0x030200) {

         visible_width  = get_bits_long(gb, 24);
         visible_height = get_bits_long(gb, 24);

         skip_bits(gb, 8); /* offset x */
         skip_bits(gb, 8); /* offset y */
     }

     skip_bits(gb, 32); /* fps numerator */
     skip_bits(gb, 32); /* fps denumerator */
     skip_bits(gb, 24); /* aspect numerator */
     skip_bits(gb, 24); /* aspect denumerator */

     if (s->theora < 0x030200)

         skip_bits(gb, 5); /* keyframe frequency force */
     skip_bits(gb, 8); /* colorspace */

     if (s->theora >= 0x030400)

         skip_bits(gb, 2); /* pixel format: 420,res,422,444 */
     skip_bits(gb, 24); /* bitrate */

     skip_bits(gb, 6); /* quality hint */

     if (s->theora >= 0x030200)

     {

         skip_bits(gb, 5); /* keyframe frequency force */

         if (s->theora < 0x030400)

             skip_bits(gb, 5); /* spare bits */

     }

 //    align_get_bits(gb);

     if (   visible_width  <= s->width  && visible_width  > s->width-16
         && visible_height <= s->height && visible_height > s->height-16)
         avcodec_set_dimensions(avctx, visible_width, visible_height);
     else
         avcodec_set_dimensions(avctx, s->width, s->height);

 
     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 */

         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 (ff_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(&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;

   }

     vp3_decode_init(avctx);

     return 0;
 }
 

 AVCodec theora_decoder = {
     "theora",

     CODEC_TYPE_VIDEO,

     CODEC_ID_THEORA,

     sizeof(Vp3DecodeContext),

     theora_decode_init,

     NULL,
     vp3_decode_end,
     vp3_decode_frame,
     0,

     NULL,

     .long_name = NULL_IF_CONFIG_SMALL("Theora"),

 };

 #endif

 AVCodec vp3_decoder = {
     "vp3",

     CODEC_TYPE_VIDEO,

     CODEC_ID_VP3,

     sizeof(Vp3DecodeContext),

     vp3_decode_init,

     NULL,
     vp3_decode_end,
     vp3_decode_frame,
     0,

     NULL,

     .long_name = NULL_IF_CONFIG_SMALL("On2 VP3"),

 };