git.sesse.net Git - ffmpeg/blob - libavcodec/snowdec.c

   1 /*
   2  * Copyright (C) 2004 Michael Niedermayer <michaelni@gmx.at>
   3  *
   4  * This file is part of FFmpeg.
   5  *
   6  * FFmpeg is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * FFmpeg is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with FFmpeg; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #include "libavutil/intmath.h"
  22 #include "libavutil/log.h"
  23 #include "libavutil/opt.h"
  24 #include "avcodec.h"
  25 #include "snow_dwt.h"
  26 #include "internal.h"
  27 #include "snow.h"
  28
  29 #include "rangecoder.h"
  30 #include "mathops.h"
  31
  32 #include "mpegvideo.h"
  33 #include "h263.h"
  34
  35 static av_always_inline void predict_slice_buffered(SnowContext *s, slice_buffer * sb, IDWTELEM * old_buffer, int plane_index, int add, int mb_y){
  36     Plane *p= &s->plane[plane_index];
  37     const int mb_w= s->b_width  << s->block_max_depth;
  38     const int mb_h= s->b_height << s->block_max_depth;
  39     int x, y, mb_x;
  40     int block_size = MB_SIZE >> s->block_max_depth;
  41     int block_w    = plane_index ? block_size>>s->chroma_h_shift : block_size;
  42     int block_h    = plane_index ? block_size>>s->chroma_v_shift : block_size;
  43     const uint8_t *obmc  = plane_index ? ff_obmc_tab[s->block_max_depth+s->chroma_h_shift] : ff_obmc_tab[s->block_max_depth];
  44     int obmc_stride= plane_index ? (2*block_size)>>s->chroma_h_shift : 2*block_size;
  45     int ref_stride= s->current_picture->linesize[plane_index];
  46     uint8_t *dst8= s->current_picture->data[plane_index];
  47     int w= p->width;
  48     int h= p->height;
  49
  50     if(s->keyframe || (s->avctx->debug&512)){
  51         if(mb_y==mb_h)
  52             return;
  53
  54         if(add){
  55             for(y=block_h*mb_y; y<FFMIN(h,block_h*(mb_y+1)); y++){
  56 //                DWTELEM * line = slice_buffer_get_line(sb, y);
  57                 IDWTELEM * line = sb->line[y];
  58                 for(x=0; x<w; x++){
  59 //                    int v= buf[x + y*w] + (128<<FRAC_BITS) + (1<<(FRAC_BITS-1));
  60                     int v= line[x] + (128<<FRAC_BITS) + (1<<(FRAC_BITS-1));
  61                     v >>= FRAC_BITS;
  62                     if(v&(~255)) v= ~(v>>31);
  63                     dst8[x + y*ref_stride]= v;
  64                 }
  65             }
  66         }else{
  67             for(y=block_h*mb_y; y<FFMIN(h,block_h*(mb_y+1)); y++){
  68 //                DWTELEM * line = slice_buffer_get_line(sb, y);
  69                 IDWTELEM * line = sb->line[y];
  70                 for(x=0; x<w; x++){
  71                     line[x] -= 128 << FRAC_BITS;
  72 //                    buf[x + y*w]-= 128<<FRAC_BITS;
  73                 }
  74             }
  75         }
  76
  77         return;
  78     }
  79
  80     for(mb_x=0; mb_x<=mb_w; mb_x++){
  81         add_yblock(s, 1, sb, old_buffer, dst8, obmc,
  82                    block_w*mb_x - block_w/2,
  83                    block_h*mb_y - block_h/2,
  84                    block_w, block_h,
  85                    w, h,
  86                    w, ref_stride, obmc_stride,
  87                    mb_x - 1, mb_y - 1,
  88                    add, 0, plane_index);
  89     }
  90
  91     if(s->avmv && mb_y < mb_h && plane_index == 0)
  92         for(mb_x=0; mb_x<mb_w; mb_x++){
  93             AVMotionVector *avmv = s->avmv + s->avmv_index;
  94             const int b_width = s->b_width  << s->block_max_depth;
  95             const int b_stride= b_width;
  96             BlockNode *bn= &s->block[mb_x + mb_y*b_stride];
  97
  98             if (bn->type)
  99                 continue;
 100
 101             s->avmv_index++;
 102
 103             avmv->w = block_w;
 104             avmv->h = block_h;
 105             avmv->dst_x = block_w*mb_x - block_w/2;
 106             avmv->dst_y = block_h*mb_y - block_h/2;
 107             avmv->motion_scale = 8;
 108             avmv->motion_x = bn->mx * s->mv_scale;
 109             avmv->motion_y = bn->my * s->mv_scale;
 110             avmv->src_x = avmv->dst_x + avmv->motion_x / 8;
 111             avmv->src_y = avmv->dst_y + avmv->motion_y / 8;
 112             avmv->source= -1 - bn->ref;
 113             avmv->flags = 0;
 114         }
 115 }
 116
 117 static inline void decode_subband_slice_buffered(SnowContext *s, SubBand *b, slice_buffer * sb, int start_y, int h, int save_state[1]){
 118     const int w= b->width;
 119     int y;
 120     const int qlog= av_clip(s->qlog + b->qlog, 0, QROOT*16);
 121     int qmul= ff_qexp[qlog&(QROOT-1)]<<(qlog>>QSHIFT);
 122     int qadd= (s->qbias*qmul)>>QBIAS_SHIFT;
 123     int new_index = 0;
 124
 125     if(b->ibuf == s->spatial_idwt_buffer || s->qlog == LOSSLESS_QLOG){
 126         qadd= 0;
 127         qmul= 1<<QEXPSHIFT;
 128     }
 129
 130     /* If we are on the second or later slice, restore our index. */
 131     if (start_y != 0)
 132         new_index = save_state[0];
 133
 134
 135     for(y=start_y; y<h; y++){
 136         int x = 0;
 137         int v;
 138         IDWTELEM * line = slice_buffer_get_line(sb, y * b->stride_line + b->buf_y_offset) + b->buf_x_offset;
 139         memset(line, 0, b->width*sizeof(IDWTELEM));
 140         v = b->x_coeff[new_index].coeff;
 141         x = b->x_coeff[new_index++].x;
 142         while(x < w){
 143             register int t= (int)( (v>>1)*(unsigned)qmul + qadd)>>QEXPSHIFT;
 144             register int u= -(v&1);
 145             line[x] = (t^u) - u;
 146
 147             v = b->x_coeff[new_index].coeff;
 148             x = b->x_coeff[new_index++].x;
 149         }
 150     }
 151
 152     /* Save our variables for the next slice. */
 153     save_state[0] = new_index;
 154
 155     return;
 156 }
 157
 158 static int decode_q_branch(SnowContext *s, int level, int x, int y){
 159     const int w= s->b_width << s->block_max_depth;
 160     const int rem_depth= s->block_max_depth - level;
 161     const int index= (x + y*w) << rem_depth;
 162     int trx= (x+1)<<rem_depth;
 163     const BlockNode *left  = x ? &s->block[index-1] : &null_block;
 164     const BlockNode *top   = y ? &s->block[index-w] : &null_block;
 165     const BlockNode *tl    = y && x ? &s->block[index-w-1] : left;
 166     const BlockNode *tr    = y && trx<w && ((x&1)==0 || level==0) ? &s->block[index-w+(1<<rem_depth)] : tl; //FIXME use lt
 167     int s_context= 2*left->level + 2*top->level + tl->level + tr->level;
 168     int res;
 169
 170     if(s->keyframe){
 171         set_blocks(s, level, x, y, null_block.color[0], null_block.color[1], null_block.color[2], null_block.mx, null_block.my, null_block.ref, BLOCK_INTRA);
 172         return 0;
 173     }
 174
 175     if(level==s->block_max_depth || get_rac(&s->c, &s->block_state[4 + s_context])){
 176         int type, mx, my;
 177         int l = left->color[0];
 178         int cb= left->color[1];
 179         int cr= left->color[2];
 180         unsigned ref = 0;
 181         int ref_context= av_log2(2*left->ref) + av_log2(2*top->ref);
 182         int mx_context= av_log2(2*FFABS(left->mx - top->mx)) + 0*av_log2(2*FFABS(tr->mx - top->mx));
 183         int my_context= av_log2(2*FFABS(left->my - top->my)) + 0*av_log2(2*FFABS(tr->my - top->my));
 184
 185         type= get_rac(&s->c, &s->block_state[1 + left->type + top->type]) ? BLOCK_INTRA : 0;
 186         if(type){
 187             int ld, cbd, crd;
 188             pred_mv(s, &mx, &my, 0, left, top, tr);
 189             ld = get_symbol(&s->c, &s->block_state[32], 1);
 190             if (ld < -255 || ld > 255) {
 191                 return AVERROR_INVALIDDATA;
 192             }
 193             l += ld;
 194             if (s->nb_planes > 2) {
 195                 cbd = get_symbol(&s->c, &s->block_state[64], 1);
 196                 crd = get_symbol(&s->c, &s->block_state[96], 1);
 197                 if (cbd < -255 || cbd > 255 || crd < -255 || crd > 255) {
 198                     return AVERROR_INVALIDDATA;
 199                 }
 200                 cb += cbd;
 201                 cr += crd;
 202             }
 203         }else{
 204             if(s->ref_frames > 1)
 205                 ref= get_symbol(&s->c, &s->block_state[128 + 1024 + 32*ref_context], 0);
 206             if (ref >= s->ref_frames) {
 207                 av_log(s->avctx, AV_LOG_ERROR, "Invalid ref\n");
 208                 return AVERROR_INVALIDDATA;
 209             }
 210             pred_mv(s, &mx, &my, ref, left, top, tr);
 211             mx+= get_symbol(&s->c, &s->block_state[128 + 32*(mx_context + 16*!!ref)], 1);
 212             my+= get_symbol(&s->c, &s->block_state[128 + 32*(my_context + 16*!!ref)], 1);
 213         }
 214         set_blocks(s, level, x, y, l, cb, cr, mx, my, ref, type);
 215     }else{
 216         if ((res = decode_q_branch(s, level+1, 2*x+0, 2*y+0)) < 0 ||
 217             (res = decode_q_branch(s, level+1, 2*x+1, 2*y+0)) < 0 ||
 218             (res = decode_q_branch(s, level+1, 2*x+0, 2*y+1)) < 0 ||
 219             (res = decode_q_branch(s, level+1, 2*x+1, 2*y+1)) < 0)
 220             return res;
 221     }
 222     return 0;
 223 }
 224
 225 static void dequantize_slice_buffered(SnowContext *s, slice_buffer * sb, SubBand *b, IDWTELEM *src, int stride, int start_y, int end_y){
 226     const int w= b->width;
 227     const int qlog= av_clip(s->qlog + b->qlog, 0, QROOT*16);
 228     const int qmul= ff_qexp[qlog&(QROOT-1)]<<(qlog>>QSHIFT);
 229     const int qadd= (s->qbias*qmul)>>QBIAS_SHIFT;
 230     int x,y;
 231
 232     if(s->qlog == LOSSLESS_QLOG) return;
 233
 234     for(y=start_y; y<end_y; y++){
 235 //        DWTELEM * line = slice_buffer_get_line_from_address(sb, src + (y * stride));
 236         IDWTELEM * line = slice_buffer_get_line(sb, (y * b->stride_line) + b->buf_y_offset) + b->buf_x_offset;
 237         for(x=0; x<w; x++){
 238             int i= line[x];
 239             if(i<0){
 240                 line[x]= -((-i*(unsigned)qmul + qadd)>>(QEXPSHIFT)); //FIXME try different bias
 241             }else if(i>0){
 242                 line[x]=  (( i*(unsigned)qmul + qadd)>>(QEXPSHIFT));
 243             }
 244         }
 245     }
 246 }
 247
 248 static void correlate_slice_buffered(SnowContext *s, slice_buffer * sb, SubBand *b, IDWTELEM *src, int stride, int inverse, int use_median, int start_y, int end_y){
 249     const int w= b->width;
 250     int x,y;
 251
 252     IDWTELEM * line=0; // silence silly "could be used without having been initialized" warning
 253     IDWTELEM * prev;
 254
 255     if (start_y != 0)
 256         line = slice_buffer_get_line(sb, ((start_y - 1) * b->stride_line) + b->buf_y_offset) + b->buf_x_offset;
 257
 258     for(y=start_y; y<end_y; y++){
 259         prev = line;
 260 //        line = slice_buffer_get_line_from_address(sb, src + (y * stride));
 261         line = slice_buffer_get_line(sb, (y * b->stride_line) + b->buf_y_offset) + b->buf_x_offset;
 262         for(x=0; x<w; x++){
 263             if(x){
 264                 if(use_median){
 265                     if(y && x+1<w) line[x] += mid_pred(line[x - 1], prev[x], prev[x + 1]);
 266                     else  line[x] += line[x - 1];
 267                 }else{
 268                     if(y) line[x] += mid_pred(line[x - 1], prev[x], line[x - 1] + prev[x] - prev[x - 1]);
 269                     else  line[x] += line[x - 1];
 270                 }
 271             }else{
 272                 if(y) line[x] += prev[x];
 273             }
 274         }
 275     }
 276 }
 277
 278 static void decode_qlogs(SnowContext *s){
 279     int plane_index, level, orientation;
 280
 281     for(plane_index=0; plane_index < s->nb_planes; plane_index++){
 282         for(level=0; level<s->spatial_decomposition_count; level++){
 283             for(orientation=level ? 1:0; orientation<4; orientation++){
 284                 int q;
 285                 if     (plane_index==2) q= s->plane[1].band[level][orientation].qlog;
 286                 else if(orientation==2) q= s->plane[plane_index].band[level][1].qlog;
 287                 else                    q= get_symbol(&s->c, s->header_state, 1);
 288                 s->plane[plane_index].band[level][orientation].qlog= q;
 289             }
 290         }
 291     }
 292 }
 293
 294 #define GET_S(dst, check) \
 295     tmp= get_symbol(&s->c, s->header_state, 0);\
 296     if(!(check)){\
 297         av_log(s->avctx, AV_LOG_ERROR, "Error " #dst " is %d\n", tmp);\
 298         return AVERROR_INVALIDDATA;\
 299     }\
 300     dst= tmp;
 301
 302 static int decode_header(SnowContext *s){
 303     int plane_index, tmp;
 304     uint8_t kstate[32];
 305
 306     memset(kstate, MID_STATE, sizeof(kstate));
 307
 308     s->keyframe= get_rac(&s->c, kstate);
 309     if(s->keyframe || s->always_reset){
 310         ff_snow_reset_contexts(s);
 311         s->spatial_decomposition_type=
 312         s->qlog=
 313         s->qbias=
 314         s->mv_scale=
 315         s->block_max_depth= 0;
 316     }
 317     if(s->keyframe){
 318         GET_S(s->version, tmp <= 0U)
 319         s->always_reset= get_rac(&s->c, s->header_state);
 320         s->temporal_decomposition_type= get_symbol(&s->c, s->header_state, 0);
 321         s->temporal_decomposition_count= get_symbol(&s->c, s->header_state, 0);
 322         GET_S(s->spatial_decomposition_count, 0 < tmp && tmp <= MAX_DECOMPOSITIONS)
 323         s->colorspace_type= get_symbol(&s->c, s->header_state, 0);
 324         if (s->colorspace_type == 1) {
 325             s->avctx->pix_fmt= AV_PIX_FMT_GRAY8;
 326             s->nb_planes = 1;
 327         } else if(s->colorspace_type == 0) {
 328             s->chroma_h_shift= get_symbol(&s->c, s->header_state, 0);
 329             s->chroma_v_shift= get_symbol(&s->c, s->header_state, 0);
 330
 331             if(s->chroma_h_shift == 1 && s->chroma_v_shift==1){
 332                 s->avctx->pix_fmt= AV_PIX_FMT_YUV420P;
 333             }else if(s->chroma_h_shift == 0 && s->chroma_v_shift==0){
 334                 s->avctx->pix_fmt= AV_PIX_FMT_YUV444P;
 335             }else if(s->chroma_h_shift == 2 && s->chroma_v_shift==2){
 336                 s->avctx->pix_fmt= AV_PIX_FMT_YUV410P;
 337             } else {
 338                 av_log(s, AV_LOG_ERROR, "unsupported color subsample mode %d %d\n", s->chroma_h_shift, s->chroma_v_shift);
 339                 s->chroma_h_shift = s->chroma_v_shift = 1;
 340                 s->avctx->pix_fmt= AV_PIX_FMT_YUV420P;
 341                 return AVERROR_INVALIDDATA;
 342             }
 343             s->nb_planes = 3;
 344         } else {
 345             av_log(s, AV_LOG_ERROR, "unsupported color space\n");
 346             s->chroma_h_shift = s->chroma_v_shift = 1;
 347             s->avctx->pix_fmt= AV_PIX_FMT_YUV420P;
 348             return AVERROR_INVALIDDATA;
 349         }
 350
 351
 352         s->spatial_scalability= get_rac(&s->c, s->header_state);
 353 //        s->rate_scalability= get_rac(&s->c, s->header_state);
 354         GET_S(s->max_ref_frames, tmp < (unsigned)MAX_REF_FRAMES)
 355         s->max_ref_frames++;
 356
 357         decode_qlogs(s);
 358     }
 359
 360     if(!s->keyframe){
 361         if(get_rac(&s->c, s->header_state)){
 362             for(plane_index=0; plane_index<FFMIN(s->nb_planes, 2); plane_index++){
 363                 int htaps, i, sum=0;
 364                 Plane *p= &s->plane[plane_index];
 365                 p->diag_mc= get_rac(&s->c, s->header_state);
 366                 htaps= get_symbol(&s->c, s->header_state, 0)*2 + 2;
 367                 if((unsigned)htaps >= HTAPS_MAX || htaps==0)
 368                     return AVERROR_INVALIDDATA;
 369                 p->htaps= htaps;
 370                 for(i= htaps/2; i; i--){
 371                     p->hcoeff[i]= get_symbol(&s->c, s->header_state, 0) * (1-2*(i&1));
 372                     sum += p->hcoeff[i];
 373                 }
 374                 p->hcoeff[0]= 32-sum;
 375             }
 376             s->plane[2].diag_mc= s->plane[1].diag_mc;
 377             s->plane[2].htaps  = s->plane[1].htaps;
 378             memcpy(s->plane[2].hcoeff, s->plane[1].hcoeff, sizeof(s->plane[1].hcoeff));
 379         }
 380         if(get_rac(&s->c, s->header_state)){
 381             GET_S(s->spatial_decomposition_count, 0 < tmp && tmp <= MAX_DECOMPOSITIONS)
 382             decode_qlogs(s);
 383         }
 384     }
 385
 386     s->spatial_decomposition_type+= (unsigned)get_symbol(&s->c, s->header_state, 1);
 387     if(s->spatial_decomposition_type > 1U){
 388         av_log(s->avctx, AV_LOG_ERROR, "spatial_decomposition_type %d not supported\n", s->spatial_decomposition_type);
 389         return AVERROR_INVALIDDATA;
 390     }
 391     if(FFMIN(s->avctx-> width>>s->chroma_h_shift,
 392              s->avctx->height>>s->chroma_v_shift) >> (s->spatial_decomposition_count-1) <= 1){
 393         av_log(s->avctx, AV_LOG_ERROR, "spatial_decomposition_count %d too large for size\n", s->spatial_decomposition_count);
 394         return AVERROR_INVALIDDATA;
 395     }
 396     if (s->avctx->width > 65536-4) {
 397         av_log(s->avctx, AV_LOG_ERROR, "Width %d is too large\n", s->avctx->width);
 398         return AVERROR_INVALIDDATA;
 399     }
 400
 401
 402     s->qlog           += (unsigned)get_symbol(&s->c, s->header_state, 1);
 403     s->mv_scale       += (unsigned)get_symbol(&s->c, s->header_state, 1);
 404     s->qbias          += (unsigned)get_symbol(&s->c, s->header_state, 1);
 405     s->block_max_depth+= (unsigned)get_symbol(&s->c, s->header_state, 1);
 406     if(s->block_max_depth > 1 || s->block_max_depth < 0 || s->mv_scale > 256U){
 407         av_log(s->avctx, AV_LOG_ERROR, "block_max_depth= %d is too large\n", s->block_max_depth);
 408         s->block_max_depth= 0;
 409         s->mv_scale = 0;
 410         return AVERROR_INVALIDDATA;
 411     }
 412     if (FFABS(s->qbias) > 127) {
 413         av_log(s->avctx, AV_LOG_ERROR, "qbias %d is too large\n", s->qbias);
 414         s->qbias = 0;
 415         return AVERROR_INVALIDDATA;
 416     }
 417
 418     return 0;
 419 }
 420
 421 static av_cold int decode_init(AVCodecContext *avctx)
 422 {
 423     int ret;
 424
 425     if ((ret = ff_snow_common_init(avctx)) < 0) {
 426         return ret;
 427     }
 428
 429     return 0;
 430 }
 431
 432 static int decode_blocks(SnowContext *s){
 433     int x, y;
 434     int w= s->b_width;
 435     int h= s->b_height;
 436     int res;
 437
 438     for(y=0; y<h; y++){
 439         for(x=0; x<w; x++){
 440             if (s->c.bytestream >= s->c.bytestream_end)
 441                 return AVERROR_INVALIDDATA;
 442             if ((res = decode_q_branch(s, 0, x, y)) < 0)
 443                 return res;
 444         }
 445     }
 446     return 0;
 447 }
 448
 449 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
 450                         AVPacket *avpkt)
 451 {
 452     const uint8_t *buf = avpkt->data;
 453     int buf_size = avpkt->size;
 454     SnowContext *s = avctx->priv_data;
 455     RangeCoder * const c= &s->c;
 456     int bytes_read;
 457     AVFrame *picture = data;
 458     int level, orientation, plane_index;
 459     int res;
 460
 461     ff_init_range_decoder(c, buf, buf_size);
 462     ff_build_rac_states(c, 0.05*(1LL<<32), 256-8);
 463
 464     s->current_picture->pict_type= AV_PICTURE_TYPE_I; //FIXME I vs. P
 465     if ((res = decode_header(s)) < 0)
 466         return res;
 467     if ((res=ff_snow_common_init_after_header(avctx)) < 0)
 468         return res;
 469
 470     // realloc slice buffer for the case that spatial_decomposition_count changed
 471     ff_slice_buffer_destroy(&s->sb);
 472     if ((res = ff_slice_buffer_init(&s->sb, s->plane[0].height,
 473                                     (MB_SIZE >> s->block_max_depth) +
 474                                     s->spatial_decomposition_count * 11 + 1,
 475                                     s->plane[0].width,
 476                                     s->spatial_idwt_buffer)) < 0)
 477         return res;
 478
 479     for(plane_index=0; plane_index < s->nb_planes; plane_index++){
 480         Plane *p= &s->plane[plane_index];
 481         p->fast_mc= p->diag_mc && p->htaps==6 && p->hcoeff[0]==40
 482                                               && p->hcoeff[1]==-10
 483                                               && p->hcoeff[2]==2;
 484     }
 485
 486     ff_snow_alloc_blocks(s);
 487
 488     if((res = ff_snow_frame_start(s)) < 0)
 489         return res;
 490
 491     s->current_picture->pict_type = s->keyframe ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
 492
 493     //keyframe flag duplication mess FIXME
 494     if(avctx->debug&FF_DEBUG_PICT_INFO)
 495         av_log(avctx, AV_LOG_ERROR,
 496                "keyframe:%d qlog:%d qbias: %d mvscale: %d "
 497                "decomposition_type:%d decomposition_count:%d\n",
 498                s->keyframe, s->qlog, s->qbias, s->mv_scale,
 499                s->spatial_decomposition_type,
 500                s->spatial_decomposition_count
 501               );
 502
 503     av_assert0(!s->avmv);
 504     if (s->avctx->flags2 & AV_CODEC_FLAG2_EXPORT_MVS) {
 505         s->avmv = av_malloc_array(s->b_width * s->b_height, sizeof(AVMotionVector) << (s->block_max_depth*2));
 506     }
 507     s->avmv_index = 0;
 508
 509     if ((res = decode_blocks(s)) < 0)
 510         return res;
 511
 512     for(plane_index=0; plane_index < s->nb_planes; plane_index++){
 513         Plane *p= &s->plane[plane_index];
 514         int w= p->width;
 515         int h= p->height;
 516         int x, y;
 517         int decode_state[MAX_DECOMPOSITIONS][4][1]; /* Stored state info for unpack_coeffs. 1 variable per instance. */
 518
 519         if(s->avctx->debug&2048){
 520             memset(s->spatial_dwt_buffer, 0, sizeof(DWTELEM)*w*h);
 521             predict_plane(s, s->spatial_idwt_buffer, plane_index, 1);
 522
 523             for(y=0; y<h; y++){
 524                 for(x=0; x<w; x++){
 525                     int v= s->current_picture->data[plane_index][y*s->current_picture->linesize[plane_index] + x];
 526                     s->mconly_picture->data[plane_index][y*s->mconly_picture->linesize[plane_index] + x]= v;
 527                 }
 528             }
 529         }
 530
 531         for(level=0; level<s->spatial_decomposition_count; level++){
 532             for(orientation=level ? 1 : 0; orientation<4; orientation++){
 533                 SubBand *b= &p->band[level][orientation];
 534                 unpack_coeffs(s, b, b->parent, orientation);
 535             }
 536         }
 537
 538         {
 539         const int mb_h= s->b_height << s->block_max_depth;
 540         const int block_size = MB_SIZE >> s->block_max_depth;
 541         const int block_h    = plane_index ? block_size>>s->chroma_v_shift : block_size;
 542         int mb_y;
 543         DWTCompose cs[MAX_DECOMPOSITIONS];
 544         int yd=0, yq=0;
 545         int y;
 546         int end_y;
 547
 548         ff_spatial_idwt_buffered_init(cs, &s->sb, w, h, 1, s->spatial_decomposition_type, s->spatial_decomposition_count);
 549         for(mb_y=0; mb_y<=mb_h; mb_y++){
 550
 551             int slice_starty = block_h*mb_y;
 552             int slice_h = block_h*(mb_y+1);
 553
 554             if (!(s->keyframe || s->avctx->debug&512)){
 555                 slice_starty = FFMAX(0, slice_starty - (block_h >> 1));
 556                 slice_h -= (block_h >> 1);
 557             }
 558
 559             for(level=0; level<s->spatial_decomposition_count; level++){
 560                 for(orientation=level ? 1 : 0; orientation<4; orientation++){
 561                     SubBand *b= &p->band[level][orientation];
 562                     int start_y;
 563                     int end_y;
 564                     int our_mb_start = mb_y;
 565                     int our_mb_end = (mb_y + 1);
 566                     const int extra= 3;
 567                     start_y = (mb_y ? ((block_h * our_mb_start) >> (s->spatial_decomposition_count - level)) + s->spatial_decomposition_count - level + extra: 0);
 568                     end_y = (((block_h * our_mb_end) >> (s->spatial_decomposition_count - level)) + s->spatial_decomposition_count - level + extra);
 569                     if (!(s->keyframe || s->avctx->debug&512)){
 570                         start_y = FFMAX(0, start_y - (block_h >> (1+s->spatial_decomposition_count - level)));
 571                         end_y = FFMAX(0, end_y - (block_h >> (1+s->spatial_decomposition_count - level)));
 572                     }
 573                     start_y = FFMIN(b->height, start_y);
 574                     end_y = FFMIN(b->height, end_y);
 575
 576                     if (start_y != end_y){
 577                         if (orientation == 0){
 578                             SubBand * correlate_band = &p->band[0][0];
 579                             int correlate_end_y = FFMIN(b->height, end_y + 1);
 580                             int correlate_start_y = FFMIN(b->height, (start_y ? start_y + 1 : 0));
 581                             decode_subband_slice_buffered(s, correlate_band, &s->sb, correlate_start_y, correlate_end_y, decode_state[0][0]);
 582                             correlate_slice_buffered(s, &s->sb, correlate_band, correlate_band->ibuf, correlate_band->stride, 1, 0, correlate_start_y, correlate_end_y);
 583                             dequantize_slice_buffered(s, &s->sb, correlate_band, correlate_band->ibuf, correlate_band->stride, start_y, end_y);
 584                         }
 585                         else
 586                             decode_subband_slice_buffered(s, b, &s->sb, start_y, end_y, decode_state[level][orientation]);
 587                     }
 588                 }
 589             }
 590
 591             for(; yd<slice_h; yd+=4){
 592                 ff_spatial_idwt_buffered_slice(&s->dwt, cs, &s->sb, s->temp_idwt_buffer, w, h, 1, s->spatial_decomposition_type, s->spatial_decomposition_count, yd);
 593             }
 594
 595             if(s->qlog == LOSSLESS_QLOG){
 596                 for(; yq<slice_h && yq<h; yq++){
 597                     IDWTELEM * line = slice_buffer_get_line(&s->sb, yq);
 598                     for(x=0; x<w; x++){
 599                         line[x] *= 1<<FRAC_BITS;
 600                     }
 601                 }
 602             }
 603
 604             predict_slice_buffered(s, &s->sb, s->spatial_idwt_buffer, plane_index, 1, mb_y);
 605
 606             y = FFMIN(p->height, slice_starty);
 607             end_y = FFMIN(p->height, slice_h);
 608             while(y < end_y)
 609                 ff_slice_buffer_release(&s->sb, y++);
 610         }
 611
 612         ff_slice_buffer_flush(&s->sb);
 613         }
 614
 615     }
 616
 617     emms_c();
 618
 619     ff_snow_release_buffer(avctx);
 620
 621     if(!(s->avctx->debug&2048))
 622         res = av_frame_ref(picture, s->current_picture);
 623     else
 624         res = av_frame_ref(picture, s->mconly_picture);
 625     if (res >= 0 && s->avmv_index) {
 626         AVFrameSideData *sd;
 627
 628         sd = av_frame_new_side_data(picture, AV_FRAME_DATA_MOTION_VECTORS, s->avmv_index * sizeof(AVMotionVector));
 629         if (!sd)
 630             return AVERROR(ENOMEM);
 631         memcpy(sd->data, s->avmv, s->avmv_index * sizeof(AVMotionVector));
 632     }
 633
 634     av_freep(&s->avmv);
 635
 636     if (res < 0)
 637         return res;
 638
 639     *got_frame = 1;
 640
 641     bytes_read= c->bytestream - c->bytestream_start;
 642     if(bytes_read ==0) av_log(s->avctx, AV_LOG_ERROR, "error at end of frame\n"); //FIXME
 643
 644     return bytes_read;
 645 }
 646
 647 static av_cold int decode_end(AVCodecContext *avctx)
 648 {
 649     SnowContext *s = avctx->priv_data;
 650
 651     ff_slice_buffer_destroy(&s->sb);
 652
 653     ff_snow_common_end(s);
 654
 655     return 0;
 656 }
 657
 658 AVCodec ff_snow_decoder = {
 659     .name           = "snow",
 660     .long_name      = NULL_IF_CONFIG_SMALL("Snow"),
 661     .type           = AVMEDIA_TYPE_VIDEO,
 662     .id             = AV_CODEC_ID_SNOW,
 663     .priv_data_size = sizeof(SnowContext),
 664     .init           = decode_init,
 665     .close          = decode_end,
 666     .decode         = decode_frame,
 667     .capabilities   = AV_CODEC_CAP_DR1 /*| AV_CODEC_CAP_DRAW_HORIZ_BAND*/,
 668     .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE |
 669                       FF_CODEC_CAP_INIT_CLEANUP,
 670 };