/**

  * @file

  * VP5 and VP6 compatible video decoder (common features)
  *
  * Copyright (C) 2006  Aurelien Jacobs <aurel@gnuage.org>
  *

  * 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

  */
 
 #include "avcodec.h"

 #include "bytestream.h"

 
 #include "vp56.h"
 #include "vp56data.h"
 
 

 void ff_vp56_init_dequant(VP56Context *s, int quantizer)

 {
     s->quantizer = quantizer;
     s->dequant_dc = vp56_dc_dequant[quantizer] << 2;
     s->dequant_ac = vp56_ac_dequant[quantizer] << 2;

     memset(s->qscale_table, quantizer, s->mb_width);

 }
 

 static int vp56_get_vectors_predictors(VP56Context *s, int row, int col,
                                        VP56Frame ref_frame)

 {
     int nb_pred = 0;

     VP56mv vect[2] = {{0,0}, {0,0}};

     int pos, offset;

     VP56mv mvp;

 
     for (pos=0; pos<12; pos++) {
         mvp.x = col + vp56_candidate_predictor_pos[pos][0];
         mvp.y = row + vp56_candidate_predictor_pos[pos][1];
         if (mvp.x < 0 || mvp.x >= s->mb_width ||
             mvp.y < 0 || mvp.y >= s->mb_height)
             continue;
         offset = mvp.x + s->mb_width*mvp.y;
 
         if (vp56_reference_frame[s->macroblocks[offset].type] != ref_frame)
             continue;

         if ((s->macroblocks[offset].mv.x == vect[0].x &&
              s->macroblocks[offset].mv.y == vect[0].y) ||

             (s->macroblocks[offset].mv.x == 0 &&
              s->macroblocks[offset].mv.y == 0))
             continue;
 

         vect[nb_pred++] = s->macroblocks[offset].mv;

         if (nb_pred > 1) {
             nb_pred = -1;
             break;
         }
         s->vector_candidate_pos = pos;
     }
 

     s->vector_candidate[0] = vect[0];
     s->vector_candidate[1] = vect[1];

 
     return nb_pred+1;
 }
 

 static void vp56_parse_mb_type_models(VP56Context *s)

 {

     VP56RangeCoder *c = &s->c;

     VP56Model *model = s->modelp;

     int i, ctx, type;
 
     for (ctx=0; ctx<3; ctx++) {
         if (vp56_rac_get_prob(c, 174)) {
             int idx = vp56_rac_gets(c, 4);

             memcpy(model->mb_types_stats[ctx],
                    vp56_pre_def_mb_type_stats[idx][ctx],
                    sizeof(model->mb_types_stats[ctx]));

         }
         if (vp56_rac_get_prob(c, 254)) {
             for (type=0; type<10; type++) {
                 for(i=0; i<2; i++) {
                     if (vp56_rac_get_prob(c, 205)) {
                         int delta, sign = vp56_rac_get(c);
 
                         delta = vp56_rac_get_tree(c, vp56_pmbtm_tree,
                                                   vp56_mb_type_model_model);
                         if (!delta)
                             delta = 4 * vp56_rac_gets(c, 7);

                         model->mb_types_stats[ctx][type][i] += (delta ^ -sign) + sign;

                     }
                 }
             }
         }
     }
 
     /* compute MB type probability tables based on previous MB type */
     for (ctx=0; ctx<3; ctx++) {
         int p[10];
 
         for (type=0; type<10; type++)

             p[type] = 100 * model->mb_types_stats[ctx][type][1];

 
         for (type=0; type<10; type++) {
             int p02, p34, p0234, p17, p56, p89, p5689, p156789;
 
             /* conservative MB type probability */

             model->mb_type[ctx][type][0] = 255 - (255 * model->mb_types_stats[ctx][type][0]) / (1 + model->mb_types_stats[ctx][type][0] + model->mb_types_stats[ctx][type][1]);

 
             p[type] = 0;    /* same MB type => weight is null */
 
             /* binary tree parsing probabilities */
             p02 = p[0] + p[2];
             p34 = p[3] + p[4];
             p0234 = p02 + p34;
             p17 = p[1] + p[7];
             p56 = p[5] + p[6];
             p89 = p[8] + p[9];
             p5689 = p56 + p89;
             p156789 = p17 + p5689;
 

             model->mb_type[ctx][type][1] = 1 + 255 * p0234/(1+p0234+p156789);
             model->mb_type[ctx][type][2] = 1 + 255 * p02  / (1+p0234);
             model->mb_type[ctx][type][3] = 1 + 255 * p17  / (1+p156789);
             model->mb_type[ctx][type][4] = 1 + 255 * p[0] / (1+p02);
             model->mb_type[ctx][type][5] = 1 + 255 * p[3] / (1+p34);
             model->mb_type[ctx][type][6] = 1 + 255 * p[1] / (1+p17);
             model->mb_type[ctx][type][7] = 1 + 255 * p56  / (1+p5689);
             model->mb_type[ctx][type][8] = 1 + 255 * p[5] / (1+p56);
             model->mb_type[ctx][type][9] = 1 + 255 * p[8] / (1+p89);

 
             /* restore initial value */

             p[type] = 100 * model->mb_types_stats[ctx][type][1];

         }
     }
 }
 

 static VP56mb vp56_parse_mb_type(VP56Context *s,

                                  VP56mb prev_type, int ctx)

 {

     uint8_t *mb_type_model = s->modelp->mb_type[ctx][prev_type];

     VP56RangeCoder *c = &s->c;

 
     if (vp56_rac_get_prob(c, mb_type_model[0]))
         return prev_type;
     else
         return vp56_rac_get_tree(c, vp56_pmbt_tree, mb_type_model);
 }
 

 static void vp56_decode_4mv(VP56Context *s, int row, int col)

 {

     VP56mv mv = {0,0};

     int type[4];
     int b;
 
     /* parse each block type */
     for (b=0; b<4; b++) {
         type[b] = vp56_rac_gets(&s->c, 2);
         if (type[b])
             type[b]++;  /* only returns 0, 2, 3 or 4 (all INTER_PF) */
     }
 
     /* get vectors */
     for (b=0; b<4; b++) {
         switch (type[b]) {
             case VP56_MB_INTER_NOVEC_PF:

                 s->mv[b] = (VP56mv) {0,0};

                 break;
             case VP56_MB_INTER_DELTA_PF:
                 s->parse_vector_adjustment(s, &s->mv[b]);
                 break;
             case VP56_MB_INTER_V1_PF:
                 s->mv[b] = s->vector_candidate[0];
                 break;
             case VP56_MB_INTER_V2_PF:
                 s->mv[b] = s->vector_candidate[1];
                 break;
         }
         mv.x += s->mv[b].x;
         mv.y += s->mv[b].y;
     }
 
     /* this is the one selected for the whole MB for prediction */
     s->macroblocks[row * s->mb_width + col].mv = s->mv[3];
 
     /* chroma vectors are average luma vectors */
     if (s->avctx->codec->id == CODEC_ID_VP5) {
         s->mv[4].x = s->mv[5].x = RSHIFT(mv.x,2);
         s->mv[4].y = s->mv[5].y = RSHIFT(mv.y,2);
     } else {

         s->mv[4] = s->mv[5] = (VP56mv) {mv.x/4, mv.y/4};

     }
 }
 

 static VP56mb vp56_decode_mv(VP56Context *s, int row, int col)

 {

     VP56mv *mv, vect = {0,0};

     int ctx, b;
 
     ctx = vp56_get_vectors_predictors(s, row, col, VP56_FRAME_PREVIOUS);
     s->mb_type = vp56_parse_mb_type(s, s->mb_type, ctx);
     s->macroblocks[row * s->mb_width + col].type = s->mb_type;
 
     switch (s->mb_type) {
         case VP56_MB_INTER_V1_PF:
             mv = &s->vector_candidate[0];
             break;
 
         case VP56_MB_INTER_V2_PF:
             mv = &s->vector_candidate[1];
             break;
 
         case VP56_MB_INTER_V1_GF:
             vp56_get_vectors_predictors(s, row, col, VP56_FRAME_GOLDEN);
             mv = &s->vector_candidate[0];
             break;
 
         case VP56_MB_INTER_V2_GF:
             vp56_get_vectors_predictors(s, row, col, VP56_FRAME_GOLDEN);
             mv = &s->vector_candidate[1];
             break;
 
         case VP56_MB_INTER_DELTA_PF:

             s->parse_vector_adjustment(s, &vect);
             mv = &vect;

             break;
 
         case VP56_MB_INTER_DELTA_GF:
             vp56_get_vectors_predictors(s, row, col, VP56_FRAME_GOLDEN);

             s->parse_vector_adjustment(s, &vect);
             mv = &vect;

             break;
 
         case VP56_MB_INTER_4V:
             vp56_decode_4mv(s, row, col);
             return s->mb_type;
 
         default:

             mv = &vect;

             break;
     }
 
     s->macroblocks[row*s->mb_width + col].mv = *mv;
 
     /* same vector for all blocks */
     for (b=0; b<6; b++)
         s->mv[b] = *mv;
 
     return s->mb_type;
 }
 

 static void vp56_add_predictors_dc(VP56Context *s, VP56Frame ref_frame)

 {
     int idx = s->scantable.permutated[0];

     int b;

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

         VP56RefDc *ab = &s->above_blocks[s->above_block_idx[b]];
         VP56RefDc *lb = &s->left_block[vp56_b6to4[b]];

         int count = 0;
         int dc = 0;

         int i;

 
         if (ref_frame == lb->ref_frame) {
             dc += lb->dc_coeff;
             count++;
         }
         if (ref_frame == ab->ref_frame) {
             dc += ab->dc_coeff;
             count++;
         }

         if (s->avctx->codec->id == CODEC_ID_VP5)
             for (i=0; i<2; i++)
                 if (count < 2 && ref_frame == ab[-1+2*i].ref_frame) {
                     dc += ab[-1+2*i].dc_coeff;
                     count++;
                 }

         if (count == 0)

             dc = s->prev_dc[vp56_b2p[b]][ref_frame];

         else if (count == 2)
             dc /= 2;
 

         s->block_coeff[b][idx] += dc;
         s->prev_dc[vp56_b2p[b]][ref_frame] = s->block_coeff[b][idx];
         ab->dc_coeff = s->block_coeff[b][idx];

         ab->ref_frame = ref_frame;

         lb->dc_coeff = s->block_coeff[b][idx];

         lb->ref_frame = ref_frame;

         s->block_coeff[b][idx] *= s->dequant_dc;

     }
 }
 

 static void vp56_deblock_filter(VP56Context *s, uint8_t *yuv,

                                 int stride, int dx, int dy)
 {
     int t = vp56_filter_threshold[s->quantizer];

     if (dx)  s->vp56dsp.edge_filter_hor(yuv +         10-dx , stride, t);
     if (dy)  s->vp56dsp.edge_filter_ver(yuv + stride*(10-dy), stride, t);

 }
 

 static void vp56_mc(VP56Context *s, int b, int plane, uint8_t *src,

                     int stride, int x, int y)
 {

     uint8_t *dst=s->framep[VP56_FRAME_CURRENT]->data[plane]+s->block_offset[b];

     uint8_t *src_block;
     int src_offset;
     int overlap_offset = 0;
     int mask = s->vp56_coord_div[b] - 1;
     int deblock_filtering = s->deblock_filtering;
     int dx;
     int dy;
 
     if (s->avctx->skip_loop_filter >= AVDISCARD_ALL ||
         (s->avctx->skip_loop_filter >= AVDISCARD_NONKEY

          && !s->framep[VP56_FRAME_CURRENT]->key_frame))

         deblock_filtering = 0;
 
     dx = s->mv[b].x / s->vp56_coord_div[b];
     dy = s->mv[b].y / s->vp56_coord_div[b];
 
     if (b >= 4) {
         x /= 2;
         y /= 2;
     }
     x += dx - 2;
     y += dy - 2;
 
     if (x<0 || x+12>=s->plane_width[plane] ||
         y<0 || y+12>=s->plane_height[plane]) {

         s->dsp.emulated_edge_mc(s->edge_emu_buffer,

                             src + s->block_offset[b] + (dy-2)*stride + (dx-2),
                             stride, 12, 12, x, y,
                             s->plane_width[plane],
                             s->plane_height[plane]);
         src_block = s->edge_emu_buffer;
         src_offset = 2 + 2*stride;
     } else if (deblock_filtering) {

         /* only need a 12x12 block, but there is no such dsp function, */
         /* so copy a 16x12 block */
         s->dsp.put_pixels_tab[0][0](s->edge_emu_buffer,
                                     src + s->block_offset[b] + (dy-2)*stride + (dx-2),
                                     stride, 12);

         src_block = s->edge_emu_buffer;
         src_offset = 2 + 2*stride;
     } else {
         src_block = src;
         src_offset = s->block_offset[b] + dy*stride + dx;
     }
 
     if (deblock_filtering)
         vp56_deblock_filter(s, src_block, stride, dx&7, dy&7);
 
     if (s->mv[b].x & mask)
         overlap_offset += (s->mv[b].x > 0) ? 1 : -1;
     if (s->mv[b].y & mask)
         overlap_offset += (s->mv[b].y > 0) ? stride : -stride;
 
     if (overlap_offset) {
         if (s->filter)
             s->filter(s, dst, src_block, src_offset, src_offset+overlap_offset,
                       stride, s->mv[b], mask, s->filter_selection, b<4);
         else
             s->dsp.put_no_rnd_pixels_l2[1](dst, src_block+src_offset,
                                            src_block+src_offset+overlap_offset,
                                            stride, 8);
     } else {
         s->dsp.put_pixels_tab[1][0](dst, src_block+src_offset, stride, 8);
     }
 }
 

 static void vp56_decode_mb(VP56Context *s, int row, int col, int is_alpha)

 {
     AVFrame *frame_current, *frame_ref;

     VP56mb mb_type;
     VP56Frame ref_frame;

     int b, ab, b_max, plane, off;

     if (s->framep[VP56_FRAME_CURRENT]->key_frame)

         mb_type = VP56_MB_INTRA;
     else
         mb_type = vp56_decode_mv(s, row, col);
     ref_frame = vp56_reference_frame[mb_type];
 

     s->dsp.clear_blocks(*s->block_coeff);

 
     s->parse_coeff(s);
 
     vp56_add_predictors_dc(s, ref_frame);
 

     frame_current = s->framep[VP56_FRAME_CURRENT];
     frame_ref = s->framep[ref_frame];

     if (mb_type != VP56_MB_INTRA && !frame_ref->data[0])
         return;

     ab = 6*is_alpha;
     b_max = 6 - 2*is_alpha;
 

     switch (mb_type) {
         case VP56_MB_INTRA:

             for (b=0; b<b_max; b++) {

                 plane = vp56_b2p[b+ab];
                 s->dsp.idct_put(frame_current->data[plane] + s->block_offset[b],
                                 s->stride[plane], s->block_coeff[b]);

             }
             break;
 
         case VP56_MB_INTER_NOVEC_PF:
         case VP56_MB_INTER_NOVEC_GF:

             for (b=0; b<b_max; b++) {

                 plane = vp56_b2p[b+ab];

                 off = s->block_offset[b];

                 s->dsp.put_pixels_tab[1][0](frame_current->data[plane] + off,
                                             frame_ref->data[plane] + off,
                                             s->stride[plane], 8);
                 s->dsp.idct_add(frame_current->data[plane] + off,
                                 s->stride[plane], s->block_coeff[b]);

             }
             break;
 
         case VP56_MB_INTER_DELTA_PF:
         case VP56_MB_INTER_V1_PF:
         case VP56_MB_INTER_V2_PF:
         case VP56_MB_INTER_DELTA_GF:
         case VP56_MB_INTER_4V:
         case VP56_MB_INTER_V1_GF:
         case VP56_MB_INTER_V2_GF:

             for (b=0; b<b_max; b++) {

                 int x_off = b==1 || b==3 ? 8 : 0;
                 int y_off = b==2 || b==3 ? 8 : 0;

                 plane = vp56_b2p[b+ab];
                 vp56_mc(s, b, plane, frame_ref->data[plane], s->stride[plane],

                         16*col+x_off, 16*row+y_off);

                 s->dsp.idct_add(frame_current->data[plane] + s->block_offset[b],
                                 s->stride[plane], s->block_coeff[b]);

             }
             break;
     }
 }
 

 static int vp56_size_changed(AVCodecContext *avctx)

 {

     VP56Context *s = avctx->priv_data;

     int stride = s->framep[VP56_FRAME_CURRENT]->linesize[0];

     int i;
 

     s->plane_width[0]  = s->plane_width[3]  = avctx->coded_width;

     s->plane_width[1]  = s->plane_width[2]  = avctx->coded_width/2;

     s->plane_height[0] = s->plane_height[3] = avctx->coded_height;

     s->plane_height[1] = s->plane_height[2] = avctx->coded_height/2;

     for (i=0; i<4; i++)

         s->stride[i] = s->flip * s->framep[VP56_FRAME_CURRENT]->linesize[i];

     s->mb_width  = (avctx->coded_width +15) / 16;
     s->mb_height = (avctx->coded_height+15) / 16;

 
     if (s->mb_width > 1000 || s->mb_height > 1000) {

         avcodec_set_dimensions(avctx, 0, 0);

         av_log(avctx, AV_LOG_ERROR, "picture too big\n");
         return -1;
     }
 

     s->qscale_table = av_realloc(s->qscale_table, s->mb_width);

     s->above_blocks = av_realloc(s->above_blocks,
                                  (4*s->mb_width+6) * sizeof(*s->above_blocks));
     s->macroblocks = av_realloc(s->macroblocks,
                                 s->mb_width*s->mb_height*sizeof(*s->macroblocks));

     av_free(s->edge_emu_buffer_alloc);
     s->edge_emu_buffer_alloc = av_malloc(16*stride);

     s->edge_emu_buffer = s->edge_emu_buffer_alloc;
     if (s->flip < 0)
         s->edge_emu_buffer += 15 * stride;
 
     return 0;
 }
 

 int ff_vp56_decode_frame(AVCodecContext *avctx, void *data, int *data_size,

                          AVPacket *avpkt)

 {

     const uint8_t *buf = avpkt->data;

     VP56Context *s = avctx->priv_data;

     AVFrame *const p = s->framep[VP56_FRAME_CURRENT];

     int remaining_buf_size = avpkt->size;

     int is_alpha, av_uninit(alpha_offset);

 
     if (s->has_alpha) {

         if (remaining_buf_size < 3)
             return -1;

         alpha_offset = bytestream_get_be24(&buf);

         remaining_buf_size -= 3;

         if (remaining_buf_size < alpha_offset)
             return -1;

     }
 
     for (is_alpha=0; is_alpha < 1+s->has_alpha; is_alpha++) {

         int mb_row, mb_col, mb_row_flip, mb_offset = 0;
         int block, y, uv, stride_y, stride_uv;
         int golden_frame = 0;
         int res;

         s->modelp = &s->models[is_alpha];

         res = s->parse_header(s, buf, remaining_buf_size, &golden_frame);

         if (!res)
             return -1;

         if (res == 2) {
             int i;
             for (i = 0; i < 4; i++) {
                 if (s->frames[i].data[0])
                     avctx->release_buffer(avctx, &s->frames[i]);
             }

             if (is_alpha) {
                 avcodec_set_dimensions(avctx, 0, 0);

                 return -1;

             }

         }
 

         if (!is_alpha) {
             p->reference = 1;
             if (avctx->get_buffer(avctx, p) < 0) {
                 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
                 return -1;
             }

             if (res == 2)
                 if (vp56_size_changed(avctx)) {
                     avctx->release_buffer(avctx, p);
                     return -1;
                 }

         }
 

         if (p->key_frame) {

             p->pict_type = AV_PICTURE_TYPE_I;

             s->default_models_init(s);
             for (block=0; block<s->mb_height*s->mb_width; block++)
                 s->macroblocks[block].type = VP56_MB_INTRA;
         } else {

             p->pict_type = AV_PICTURE_TYPE_P;

             vp56_parse_mb_type_models(s);
             s->parse_vector_models(s);
             s->mb_type = VP56_MB_INTER_NOVEC_PF;
         }

         if (s->parse_coeff_models(s))
             goto next;

         memset(s->prev_dc, 0, sizeof(s->prev_dc));
         s->prev_dc[1][VP56_FRAME_CURRENT] = 128;
         s->prev_dc[2][VP56_FRAME_CURRENT] = 128;

         for (block=0; block < 4*s->mb_width+6; block++) {

             s->above_blocks[block].ref_frame = VP56_FRAME_NONE;

             s->above_blocks[block].dc_coeff = 0;
             s->above_blocks[block].not_null_dc = 0;
         }

         s->above_blocks[2*s->mb_width + 2].ref_frame = VP56_FRAME_CURRENT;
         s->above_blocks[3*s->mb_width + 4].ref_frame = VP56_FRAME_CURRENT;

         stride_y  = p->linesize[0];
         stride_uv = p->linesize[1];

 
         if (s->flip < 0)

             mb_offset = 7;
 
         /* main macroblocks loop */
         for (mb_row=0; mb_row<s->mb_height; mb_row++) {
             if (s->flip < 0)
                 mb_row_flip = s->mb_height - mb_row - 1;
             else
                 mb_row_flip = mb_row;
 
             for (block=0; block<4; block++) {

                 s->left_block[block].ref_frame = VP56_FRAME_NONE;

                 s->left_block[block].dc_coeff = 0;
                 s->left_block[block].not_null_dc = 0;

             }

             memset(s->coeff_ctx, 0, sizeof(s->coeff_ctx));

             memset(s->coeff_ctx_last, 24, sizeof(s->coeff_ctx_last));
 
             s->above_block_idx[0] = 1;
             s->above_block_idx[1] = 2;
             s->above_block_idx[2] = 1;
             s->above_block_idx[3] = 2;
             s->above_block_idx[4] = 2*s->mb_width + 2 + 1;
             s->above_block_idx[5] = 3*s->mb_width + 4 + 1;
 
             s->block_offset[s->frbi] = (mb_row_flip*16 + mb_offset) * stride_y;
             s->block_offset[s->srbi] = s->block_offset[s->frbi] + 8*stride_y;
             s->block_offset[1] = s->block_offset[0] + 8;
             s->block_offset[3] = s->block_offset[2] + 8;
             s->block_offset[4] = (mb_row_flip*8 + mb_offset) * stride_uv;
             s->block_offset[5] = s->block_offset[4];
 
             for (mb_col=0; mb_col<s->mb_width; mb_col++) {
                 vp56_decode_mb(s, mb_row, mb_col, is_alpha);
 
                 for (y=0; y<4; y++) {
                     s->above_block_idx[y] += 2;
                     s->block_offset[y] += 16;
                 }

                 for (uv=4; uv<6; uv++) {
                     s->above_block_idx[uv] += 1;
                     s->block_offset[uv] += 8;
                 }

             }
         }
 

     next:

         if (p->key_frame || golden_frame) {
             if (s->framep[VP56_FRAME_GOLDEN]->data[0] &&
                 s->framep[VP56_FRAME_GOLDEN] != s->framep[VP56_FRAME_GOLDEN2])
                 avctx->release_buffer(avctx, s->framep[VP56_FRAME_GOLDEN]);
             s->framep[VP56_FRAME_GOLDEN] = p;
         }

         if (s->has_alpha) {
             FFSWAP(AVFrame *, s->framep[VP56_FRAME_GOLDEN],
                               s->framep[VP56_FRAME_GOLDEN2]);
             buf += alpha_offset;

             remaining_buf_size -= alpha_offset;

         }

     }
 
     if (s->framep[VP56_FRAME_PREVIOUS] == s->framep[VP56_FRAME_GOLDEN] ||
         s->framep[VP56_FRAME_PREVIOUS] == s->framep[VP56_FRAME_GOLDEN2]) {
         if (s->framep[VP56_FRAME_UNUSED] != s->framep[VP56_FRAME_GOLDEN] &&
             s->framep[VP56_FRAME_UNUSED] != s->framep[VP56_FRAME_GOLDEN2])
             FFSWAP(AVFrame *, s->framep[VP56_FRAME_PREVIOUS],
                               s->framep[VP56_FRAME_UNUSED]);
         else
             FFSWAP(AVFrame *, s->framep[VP56_FRAME_PREVIOUS],
                               s->framep[VP56_FRAME_UNUSED2]);
     } else if (s->framep[VP56_FRAME_PREVIOUS]->data[0])
         avctx->release_buffer(avctx, s->framep[VP56_FRAME_PREVIOUS]);

     FFSWAP(AVFrame *, s->framep[VP56_FRAME_CURRENT],
                       s->framep[VP56_FRAME_PREVIOUS]);

     p->qstride = 0;
     p->qscale_table = s->qscale_table;
     p->qscale_type = FF_QSCALE_TYPE_VP56;

     *(AVFrame*)data = *p;
     *data_size = sizeof(AVFrame);

     return avpkt->size;

 }
 

 av_cold void ff_vp56_init(AVCodecContext *avctx, int flip, int has_alpha)

 {

     VP56Context *s = avctx->priv_data;

     int i;
 
     s->avctx = avctx;

     avctx->pix_fmt = has_alpha ? PIX_FMT_YUVA420P : PIX_FMT_YUV420P;

     if (avctx->idct_algo == FF_IDCT_AUTO)
         avctx->idct_algo = FF_IDCT_VP3;
     dsputil_init(&s->dsp, avctx);

     ff_vp56dsp_init(&s->vp56dsp, avctx->codec->id);

     ff_init_scantable(s->dsp.idct_permutation, &s->scantable,ff_zigzag_direct);
 

     for (i=0; i<4; i++) {

         s->framep[i] = &s->frames[i];

         avcodec_get_frame_defaults(&s->frames[i]);
     }

     s->framep[VP56_FRAME_UNUSED] = s->framep[VP56_FRAME_GOLDEN];

     s->framep[VP56_FRAME_UNUSED2] = s->framep[VP56_FRAME_GOLDEN2];

     s->edge_emu_buffer_alloc = NULL;
 
     s->above_blocks = NULL;
     s->macroblocks = NULL;
     s->quantizer = -1;
     s->deblock_filtering = 1;
 
     s->filter = NULL;
 

     s->has_alpha = has_alpha;

     if (flip) {
         s->flip = -1;
         s->frbi = 2;
         s->srbi = 0;
     } else {
         s->flip = 1;
         s->frbi = 0;
         s->srbi = 2;
     }
 }
 

 av_cold int ff_vp56_free(AVCodecContext *avctx)

 {

     VP56Context *s = avctx->priv_data;

     av_freep(&s->qscale_table);

     av_freep(&s->above_blocks);
     av_freep(&s->macroblocks);
     av_freep(&s->edge_emu_buffer_alloc);

     if (s->framep[VP56_FRAME_GOLDEN]->data[0])

         avctx->release_buffer(avctx, s->framep[VP56_FRAME_GOLDEN]);

     if (s->framep[VP56_FRAME_GOLDEN2]->data[0])
         avctx->release_buffer(avctx, s->framep[VP56_FRAME_GOLDEN2]);

     if (s->framep[VP56_FRAME_PREVIOUS]->data[0])
         avctx->release_buffer(avctx, s->framep[VP56_FRAME_PREVIOUS]);

     return 0;
 }