/*

  * 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 "videodsp.h"

 #include "vp3data.h"

 #include "vp3dsp.h"

 #include "xiph.h"

 #include "thread.h"

 
 #define FRAGMENT_PIXELS 8
 

 //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
 

 static int theora_decode_header(AVCodecContext *avctx, GetBitContext *gb);
 static int theora_decode_tables(AVCodecContext *avctx, GetBitContext *gb);
 
 

 /* 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;

     VideoDSPContext vdsp;

     VP3DSPContext vp3dsp;

     DECLARE_ALIGNED(16, int16_t, block)[64];

     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
  ************************************************************************/
 

 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 av_cold int vp3_decode_end(AVCodecContext *avctx)
 {
     Vp3DecodeContext *s = avctx->priv_data;
     int i;
 

     av_freep(&s->superblock_coding);
     av_freep(&s->all_fragments);
     av_freep(&s->coded_fragment_list[0]);
     av_freep(&s->dct_tokens_base);
     av_freep(&s->superblock_fragments);
     av_freep(&s->macroblock_coding);
     av_freep(&s->motion_val[0]);
     av_freep(&s->motion_val[1]);
     av_freep(&s->edge_emu_buffer);

     s->theora_tables = 0;
 

     if (avctx->internal->is_copy)
         return 0;
 
     for (i = 0; i < 16; i++) {

         ff_free_vlc(&s->dc_vlc[i]);
         ff_free_vlc(&s->ac_vlc_1[i]);
         ff_free_vlc(&s->ac_vlc_2[i]);
         ff_free_vlc(&s->ac_vlc_3[i]);
         ff_free_vlc(&s->ac_vlc_4[i]);

     }
 

     ff_free_vlc(&s->superblock_run_length_vlc);
     ff_free_vlc(&s->fragment_run_length_vlc);
     ff_free_vlc(&s->mode_code_vlc);
     ff_free_vlc(&s->motion_vector_vlc);

 
     /* release all frames */
     vp3_decode_flush(avctx);
 
     return 0;
 }
 

 /**

  * 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]];

     av_assert0(filter_limit < 128U);

 
     /* 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;

     int16_t 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->vp3dsp.h_loop_filter(

                         plane_data + 8*x,

                         stride, bounding_values);
                 }

                 /* do not perform top edge filter for top row fragments */
                 if (y > 0) {

                     s->vp3dsp.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->vp3dsp.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->vp3dsp.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, int16_t 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 i;

             }

             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);

     // return value is expected to be a valid level
     i--;

 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;

     int16_t *block = s->block;

     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->vdsp.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->vp3dsp.put_no_rnd_pixels_l2(

                                 output_plane + first_pixel,

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

                                 stride, 8);
                         }
                     }
 
                     /* 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);

                         s->vp3dsp.idct_put(

                             output_plane + first_pixel,

                             stride,
                             block);
                     } else {

                         if (vp3_dequant(s, s->all_fragments + i, plane, 1, block)) {

                         s->vp3dsp.idct_add(

                             output_plane + first_pixel,

                             stride,
                             block);

                         } else {

                             s->vp3dsp.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->codec_id != AV_CODEC_ID_THEORA)

         avctx->pix_fmt = AV_PIX_FMT_YUV420P;

     avctx->chroma_sample_location = AVCHROMA_LOC_CENTER;

     ff_dsputil_init(&s->dsp, avctx);

     ff_videodsp_init(&s->vdsp, 8);

     ff_vp3dsp_init(&s->vp3dsp, avctx->flags);

     ff_init_scantable_permutation(s->dsp.idct_permutation, s->vp3dsp.idct_perm);

     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, keyframe);

         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 *got_frame,

                             AVPacket *avpkt)

 {

     const uint8_t *buf = avpkt->data;
     int buf_size = avpkt->size;

     Vp3DecodeContext *s = avctx->priv_data;
     GetBitContext gb;

     int i;

     int ret;

 
     init_get_bits(&gb, buf, buf_size * 8);

 #if CONFIG_THEORA_DECODER

     if (s->theora && get_bits1(&gb))
     {

         int type = get_bits(&gb, 7);
         skip_bits_long(&gb, 6*8); /* "theora" */
 

         if (s->avctx->active_thread_type&FF_THREAD_FRAME) {
             av_log(avctx, AV_LOG_ERROR, "midstream reconfiguration with multithreading is unsupported, try -threads 1\n");
             return AVERROR_PATCHWELCOME;
         }

         if (type == 0) {
             vp3_decode_end(avctx);
             ret = theora_decode_header(avctx, &gb);
 
             if (ret < 0) {
                 vp3_decode_end(avctx);
             } else
                 ret = vp3_decode_init(avctx);
             return ret;
         } else if (type == 2) {
             ret = theora_decode_tables(avctx, &gb);
             if (ret < 0) {
                 vp3_decode_end(avctx);
             } else
                 ret = vp3_decode_init(avctx);
             return ret;
         }
 

         av_log(avctx, AV_LOG_ERROR, "Header packet passed to frame decoder, skipping\n");
         return -1;

     }

 #endif

 
     s->keyframe = !get_bits1(&gb);

     if (!s->all_fragments) {
         av_log(avctx, AV_LOG_ERROR, "Data packet without prior valid headers\n");
         return -1;
     }

     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);

     *got_frame = 1;

     *(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 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_dlog(avctx, "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;
 }
 

 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;
 }
 

 #if CONFIG_THEORA_DECODER

 static const enum AVPixelFormat theora_pix_fmts[4] = {
     AV_PIX_FMT_YUV420P, AV_PIX_FMT_NONE, AV_PIX_FMT_YUV422P, AV_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)];

         if (avctx->pix_fmt == AV_PIX_FMT_NONE) {
             av_log(avctx, AV_LOG_ERROR, "Invalid pixel format\n");
             return AVERROR_INVALIDDATA;
         }

         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;

     avctx->pix_fmt = AV_PIX_FMT_YUV420P;

     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++) {

     if (header_len[i] <= 0)
         continue;

     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:

             if (theora_decode_header(avctx, &gb) < 0)
                 return -1;

                 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);

 }
 

 AVCodec ff_theora_decoder = {

     .name                  = "theora",
     .type                  = AVMEDIA_TYPE_VIDEO,

     .id                    = AV_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                    = AV_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),

 };