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= ( (v>>1)*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
 187         if(type){
 188             pred_mv(s, &mx, &my, 0, left, top, tr);
 189             l += get_symbol(&s->c, &s->block_state[32], 1);
 190             if (s->nb_planes > 2) {
 191                 cb+= get_symbol(&s->c, &s->block_state[64], 1);
 192                 cr+= get_symbol(&s->c, &s->block_state[96], 1);
 193             }
 194         }else{
 195             if(s->ref_frames > 1)
 196                 ref= get_symbol(&s->c, &s->block_state[128 + 1024 + 32*ref_context], 0);
 197             if (ref >= s->ref_frames) {
 198                 av_log(s->avctx, AV_LOG_ERROR, "Invalid ref\n");
 199                 return AVERROR_INVALIDDATA;
 200             }
 201             pred_mv(s, &mx, &my, ref, left, top, tr);
 202             mx+= get_symbol(&s->c, &s->block_state[128 + 32*(mx_context + 16*!!ref)], 1);
 203             my+= get_symbol(&s->c, &s->block_state[128 + 32*(my_context + 16*!!ref)], 1);
 204         }
 205         set_blocks(s, level, x, y, l, cb, cr, mx, my, ref, type);
 206     }else{
 207         if ((res = decode_q_branch(s, level+1, 2*x+0, 2*y+0)) < 0 ||
 208             (res = decode_q_branch(s, level+1, 2*x+1, 2*y+0)) < 0 ||
 209             (res = decode_q_branch(s, level+1, 2*x+0, 2*y+1)) < 0 ||
 210             (res = decode_q_branch(s, level+1, 2*x+1, 2*y+1)) < 0)
 211             return res;
 212     }
 213     return 0;
 214 }
 215
 216 static void dequantize_slice_buffered(SnowContext *s, slice_buffer * sb, SubBand *b, IDWTELEM *src, int stride, int start_y, int end_y){
 217     const int w= b->width;
 218     const int qlog= av_clip(s->qlog + b->qlog, 0, QROOT*16);
 219     const int qmul= ff_qexp[qlog&(QROOT-1)]<<(qlog>>QSHIFT);
 220     const int qadd= (s->qbias*qmul)>>QBIAS_SHIFT;
 221     int x,y;
 222
 223     if(s->qlog == LOSSLESS_QLOG) return;
 224
 225     for(y=start_y; y<end_y; y++){
 226 //        DWTELEM * line = slice_buffer_get_line_from_address(sb, src + (y * stride));
 227         IDWTELEM * line = slice_buffer_get_line(sb, (y * b->stride_line) + b->buf_y_offset) + b->buf_x_offset;
 228         for(x=0; x<w; x++){
 229             int i= line[x];
 230             if(i<0){
 231                 line[x]= -((-i*qmul + qadd)>>(QEXPSHIFT)); //FIXME try different bias
 232             }else if(i>0){
 233                 line[x]=  (( i*qmul + qadd)>>(QEXPSHIFT));
 234             }
 235         }
 236     }
 237 }
 238
 239 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){
 240     const int w= b->width;
 241     int x,y;
 242
 243     IDWTELEM * line=0; // silence silly "could be used without having been initialized" warning
 244     IDWTELEM * prev;
 245
 246     if (start_y != 0)
 247         line = slice_buffer_get_line(sb, ((start_y - 1) * b->stride_line) + b->buf_y_offset) + b->buf_x_offset;
 248
 249     for(y=start_y; y<end_y; y++){
 250         prev = line;
 251 //        line = slice_buffer_get_line_from_address(sb, src + (y * stride));
 252         line = slice_buffer_get_line(sb, (y * b->stride_line) + b->buf_y_offset) + b->buf_x_offset;
 253         for(x=0; x<w; x++){
 254             if(x){
 255                 if(use_median){
 256                     if(y && x+1<w) line[x] += mid_pred(line[x - 1], prev[x], prev[x + 1]);
 257                     else  line[x] += line[x - 1];
 258                 }else{
 259                     if(y) line[x] += mid_pred(line[x - 1], prev[x], line[x - 1] + prev[x] - prev[x - 1]);
 260                     else  line[x] += line[x - 1];
 261                 }
 262             }else{
 263                 if(y) line[x] += prev[x];
 264             }
 265         }
 266     }
 267 }
 268
 269 static void decode_qlogs(SnowContext *s){
 270     int plane_index, level, orientation;
 271
 272     for(plane_index=0; plane_index < s->nb_planes; plane_index++){
 273         for(level=0; level<s->spatial_decomposition_count; level++){
 274             for(orientation=level ? 1:0; orientation<4; orientation++){
 275                 int q;
 276                 if     (plane_index==2) q= s->plane[1].band[level][orientation].qlog;
 277                 else if(orientation==2) q= s->plane[plane_index].band[level][1].qlog;
 278                 else                    q= get_symbol(&s->c, s->header_state, 1);
 279                 s->plane[plane_index].band[level][orientation].qlog= q;
 280             }
 281         }
 282     }
 283 }
 284
 285 #define GET_S(dst, check) \
 286     tmp= get_symbol(&s->c, s->header_state, 0);\
 287     if(!(check)){\
 288         av_log(s->avctx, AV_LOG_ERROR, "Error " #dst " is %d\n", tmp);\
 289         return AVERROR_INVALIDDATA;\
 290     }\
 291     dst= tmp;
 292
 293 static int decode_header(SnowContext *s){
 294     int plane_index, tmp;
 295     uint8_t kstate[32];
 296
 297     memset(kstate, MID_STATE, sizeof(kstate));
 298
 299     s->keyframe= get_rac(&s->c, kstate);
 300     if(s->keyframe || s->always_reset){
 301         ff_snow_reset_contexts(s);
 302         s->spatial_decomposition_type=
 303         s->qlog=
 304         s->qbias=
 305         s->mv_scale=
 306         s->block_max_depth= 0;
 307     }
 308     if(s->keyframe){
 309         GET_S(s->version, tmp <= 0U)
 310         s->always_reset= get_rac(&s->c, s->header_state);
 311         s->temporal_decomposition_type= get_symbol(&s->c, s->header_state, 0);
 312         s->temporal_decomposition_count= get_symbol(&s->c, s->header_state, 0);
 313         GET_S(s->spatial_decomposition_count, 0 < tmp && tmp <= MAX_DECOMPOSITIONS)
 314         s->colorspace_type= get_symbol(&s->c, s->header_state, 0);
 315         if (s->colorspace_type == 1) {
 316             s->avctx->pix_fmt= AV_PIX_FMT_GRAY8;
 317             s->nb_planes = 1;
 318         } else if(s->colorspace_type == 0) {
 319             s->chroma_h_shift= get_symbol(&s->c, s->header_state, 0);
 320             s->chroma_v_shift= get_symbol(&s->c, s->header_state, 0);
 321
 322             if(s->chroma_h_shift == 1 && s->chroma_v_shift==1){
 323                 s->avctx->pix_fmt= AV_PIX_FMT_YUV420P;
 324             }else if(s->chroma_h_shift == 0 && s->chroma_v_shift==0){
 325                 s->avctx->pix_fmt= AV_PIX_FMT_YUV444P;
 326             }else if(s->chroma_h_shift == 2 && s->chroma_v_shift==2){
 327                 s->avctx->pix_fmt= AV_PIX_FMT_YUV410P;
 328             } else {
 329                 av_log(s, AV_LOG_ERROR, "unsupported color subsample mode %d %d\n", s->chroma_h_shift, s->chroma_v_shift);
 330                 s->chroma_h_shift = s->chroma_v_shift = 1;
 331                 s->avctx->pix_fmt= AV_PIX_FMT_YUV420P;
 332                 return AVERROR_INVALIDDATA;
 333             }
 334             s->nb_planes = 3;
 335         } else {
 336             av_log(s, AV_LOG_ERROR, "unsupported color space\n");
 337             s->chroma_h_shift = s->chroma_v_shift = 1;
 338             s->avctx->pix_fmt= AV_PIX_FMT_YUV420P;
 339             return AVERROR_INVALIDDATA;
 340         }
 341
 342
 343         s->spatial_scalability= get_rac(&s->c, s->header_state);
 344 //        s->rate_scalability= get_rac(&s->c, s->header_state);
 345         GET_S(s->max_ref_frames, tmp < (unsigned)MAX_REF_FRAMES)
 346         s->max_ref_frames++;
 347
 348         decode_qlogs(s);
 349     }
 350
 351     if(!s->keyframe){
 352         if(get_rac(&s->c, s->header_state)){
 353             for(plane_index=0; plane_index<FFMIN(s->nb_planes, 2); plane_index++){
 354                 int htaps, i, sum=0;
 355                 Plane *p= &s->plane[plane_index];
 356                 p->diag_mc= get_rac(&s->c, s->header_state);
 357                 htaps= get_symbol(&s->c, s->header_state, 0)*2 + 2;
 358                 if((unsigned)htaps > HTAPS_MAX || htaps==0)
 359                     return AVERROR_INVALIDDATA;
 360                 p->htaps= htaps;
 361                 for(i= htaps/2; i; i--){
 362                     p->hcoeff[i]= get_symbol(&s->c, s->header_state, 0) * (1-2*(i&1));
 363                     sum += p->hcoeff[i];
 364                 }
 365                 p->hcoeff[0]= 32-sum;
 366             }
 367             s->plane[2].diag_mc= s->plane[1].diag_mc;
 368             s->plane[2].htaps  = s->plane[1].htaps;
 369             memcpy(s->plane[2].hcoeff, s->plane[1].hcoeff, sizeof(s->plane[1].hcoeff));
 370         }
 371         if(get_rac(&s->c, s->header_state)){
 372             GET_S(s->spatial_decomposition_count, 0 < tmp && tmp <= MAX_DECOMPOSITIONS)
 373             decode_qlogs(s);
 374         }
 375     }
 376
 377     s->spatial_decomposition_type+= get_symbol(&s->c, s->header_state, 1);
 378     if(s->spatial_decomposition_type > 1U){
 379         av_log(s->avctx, AV_LOG_ERROR, "spatial_decomposition_type %d not supported\n", s->spatial_decomposition_type);
 380         return AVERROR_INVALIDDATA;
 381     }
 382     if(FFMIN(s->avctx-> width>>s->chroma_h_shift,
 383              s->avctx->height>>s->chroma_v_shift) >> (s->spatial_decomposition_count-1) <= 1){
 384         av_log(s->avctx, AV_LOG_ERROR, "spatial_decomposition_count %d too large for size\n", s->spatial_decomposition_count);
 385         return AVERROR_INVALIDDATA;
 386     }
 387
 388
 389     s->qlog           += get_symbol(&s->c, s->header_state, 1);
 390     s->mv_scale       += get_symbol(&s->c, s->header_state, 1);
 391     s->qbias          += get_symbol(&s->c, s->header_state, 1);
 392     s->block_max_depth+= get_symbol(&s->c, s->header_state, 1);
 393     if(s->block_max_depth > 1 || s->block_max_depth < 0){
 394         av_log(s->avctx, AV_LOG_ERROR, "block_max_depth= %d is too large\n", s->block_max_depth);
 395         s->block_max_depth= 0;
 396         return AVERROR_INVALIDDATA;
 397     }
 398
 399     return 0;
 400 }
 401
 402 static av_cold int decode_init(AVCodecContext *avctx)
 403 {
 404     int ret;
 405
 406     if ((ret = ff_snow_common_init(avctx)) < 0) {
 407         return ret;
 408     }
 409
 410     return 0;
 411 }
 412
 413 static int decode_blocks(SnowContext *s){
 414     int x, y;
 415     int w= s->b_width;
 416     int h= s->b_height;
 417     int res;
 418
 419     for(y=0; y<h; y++){
 420         for(x=0; x<w; x++){
 421             if ((res = decode_q_branch(s, 0, x, y)) < 0)
 422                 return res;
 423         }
 424     }
 425     return 0;
 426 }
 427
 428 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
 429                         AVPacket *avpkt)
 430 {
 431     const uint8_t *buf = avpkt->data;
 432     int buf_size = avpkt->size;
 433     SnowContext *s = avctx->priv_data;
 434     RangeCoder * const c= &s->c;
 435     int bytes_read;
 436     AVFrame *picture = data;
 437     int level, orientation, plane_index;
 438     int res;
 439
 440     ff_init_range_decoder(c, buf, buf_size);
 441     ff_build_rac_states(c, 0.05*(1LL<<32), 256-8);
 442
 443     s->current_picture->pict_type= AV_PICTURE_TYPE_I; //FIXME I vs. P
 444     if ((res = decode_header(s)) < 0)
 445         return res;
 446     if ((res=ff_snow_common_init_after_header(avctx)) < 0)
 447         return res;
 448
 449     // realloc slice buffer for the case that spatial_decomposition_count changed
 450     ff_slice_buffer_destroy(&s->sb);
 451     if ((res = ff_slice_buffer_init(&s->sb, s->plane[0].height,
 452                                     (MB_SIZE >> s->block_max_depth) +
 453                                     s->spatial_decomposition_count * 11 + 1,
 454                                     s->plane[0].width,
 455                                     s->spatial_idwt_buffer)) < 0)
 456         return res;
 457
 458     for(plane_index=0; plane_index < s->nb_planes; plane_index++){
 459         Plane *p= &s->plane[plane_index];
 460         p->fast_mc= p->diag_mc && p->htaps==6 && p->hcoeff[0]==40
 461                                               && p->hcoeff[1]==-10
 462                                               && p->hcoeff[2]==2;
 463     }
 464
 465     ff_snow_alloc_blocks(s);
 466
 467     if((res = ff_snow_frame_start(s)) < 0)
 468         return res;
 469
 470     s->current_picture->pict_type = s->keyframe ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
 471
 472     //keyframe flag duplication mess FIXME
 473     if(avctx->debug&FF_DEBUG_PICT_INFO)
 474         av_log(avctx, AV_LOG_ERROR,
 475                "keyframe:%d qlog:%d qbias: %d mvscale: %d "
 476                "decomposition_type:%d decomposition_count:%d\n",
 477                s->keyframe, s->qlog, s->qbias, s->mv_scale,
 478                s->spatial_decomposition_type,
 479                s->spatial_decomposition_count
 480               );
 481
 482     av_assert0(!s->avmv);
 483     if (s->avctx->flags2 & AV_CODEC_FLAG2_EXPORT_MVS) {
 484         s->avmv = av_malloc_array(s->b_width * s->b_height, sizeof(AVMotionVector) << (s->block_max_depth*2));
 485     }
 486     s->avmv_index = 0;
 487
 488     if ((res = decode_blocks(s)) < 0)
 489         return res;
 490
 491     for(plane_index=0; plane_index < s->nb_planes; plane_index++){
 492         Plane *p= &s->plane[plane_index];
 493         int w= p->width;
 494         int h= p->height;
 495         int x, y;
 496         int decode_state[MAX_DECOMPOSITIONS][4][1]; /* Stored state info for unpack_coeffs. 1 variable per instance. */
 497
 498         if(s->avctx->debug&2048){
 499             memset(s->spatial_dwt_buffer, 0, sizeof(DWTELEM)*w*h);
 500             predict_plane(s, s->spatial_idwt_buffer, plane_index, 1);
 501
 502             for(y=0; y<h; y++){
 503                 for(x=0; x<w; x++){
 504                     int v= s->current_picture->data[plane_index][y*s->current_picture->linesize[plane_index] + x];
 505                     s->mconly_picture->data[plane_index][y*s->mconly_picture->linesize[plane_index] + x]= v;
 506                 }
 507             }
 508         }
 509
 510         {
 511         for(level=0; level<s->spatial_decomposition_count; level++){
 512             for(orientation=level ? 1 : 0; orientation<4; orientation++){
 513                 SubBand *b= &p->band[level][orientation];
 514                 unpack_coeffs(s, b, b->parent, orientation);
 515             }
 516         }
 517         }
 518
 519         {
 520         const int mb_h= s->b_height << s->block_max_depth;
 521         const int block_size = MB_SIZE >> s->block_max_depth;
 522         const int block_h    = plane_index ? block_size>>s->chroma_v_shift : block_size;
 523         int mb_y;
 524         DWTCompose cs[MAX_DECOMPOSITIONS];
 525         int yd=0, yq=0;
 526         int y;
 527         int end_y;
 528
 529         ff_spatial_idwt_buffered_init(cs, &s->sb, w, h, 1, s->spatial_decomposition_type, s->spatial_decomposition_count);
 530         for(mb_y=0; mb_y<=mb_h; mb_y++){
 531
 532             int slice_starty = block_h*mb_y;
 533             int slice_h = block_h*(mb_y+1);
 534
 535             if (!(s->keyframe || s->avctx->debug&512)){
 536                 slice_starty = FFMAX(0, slice_starty - (block_h >> 1));
 537                 slice_h -= (block_h >> 1);
 538             }
 539
 540             for(level=0; level<s->spatial_decomposition_count; level++){
 541                 for(orientation=level ? 1 : 0; orientation<4; orientation++){
 542                     SubBand *b= &p->band[level][orientation];
 543                     int start_y;
 544                     int end_y;
 545                     int our_mb_start = mb_y;
 546                     int our_mb_end = (mb_y + 1);
 547                     const int extra= 3;
 548                     start_y = (mb_y ? ((block_h * our_mb_start) >> (s->spatial_decomposition_count - level)) + s->spatial_decomposition_count - level + extra: 0);
 549                     end_y = (((block_h * our_mb_end) >> (s->spatial_decomposition_count - level)) + s->spatial_decomposition_count - level + extra);
 550                     if (!(s->keyframe || s->avctx->debug&512)){
 551                         start_y = FFMAX(0, start_y - (block_h >> (1+s->spatial_decomposition_count - level)));
 552                         end_y = FFMAX(0, end_y - (block_h >> (1+s->spatial_decomposition_count - level)));
 553                     }
 554                     start_y = FFMIN(b->height, start_y);
 555                     end_y = FFMIN(b->height, end_y);
 556
 557                     if (start_y != end_y){
 558                         if (orientation == 0){
 559                             SubBand * correlate_band = &p->band[0][0];
 560                             int correlate_end_y = FFMIN(b->height, end_y + 1);
 561                             int correlate_start_y = FFMIN(b->height, (start_y ? start_y + 1 : 0));
 562                             decode_subband_slice_buffered(s, correlate_band, &s->sb, correlate_start_y, correlate_end_y, decode_state[0][0]);
 563                             correlate_slice_buffered(s, &s->sb, correlate_band, correlate_band->ibuf, correlate_band->stride, 1, 0, correlate_start_y, correlate_end_y);
 564                             dequantize_slice_buffered(s, &s->sb, correlate_band, correlate_band->ibuf, correlate_band->stride, start_y, end_y);
 565                         }
 566                         else
 567                             decode_subband_slice_buffered(s, b, &s->sb, start_y, end_y, decode_state[level][orientation]);
 568                     }
 569                 }
 570             }
 571
 572             for(; yd<slice_h; yd+=4){
 573                 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);
 574             }
 575
 576             if(s->qlog == LOSSLESS_QLOG){
 577                 for(; yq<slice_h && yq<h; yq++){
 578                     IDWTELEM * line = slice_buffer_get_line(&s->sb, yq);
 579                     for(x=0; x<w; x++){
 580                         line[x] <<= FRAC_BITS;
 581                     }
 582                 }
 583             }
 584
 585             predict_slice_buffered(s, &s->sb, s->spatial_idwt_buffer, plane_index, 1, mb_y);
 586
 587             y = FFMIN(p->height, slice_starty);
 588             end_y = FFMIN(p->height, slice_h);
 589             while(y < end_y)
 590                 ff_slice_buffer_release(&s->sb, y++);
 591         }
 592
 593         ff_slice_buffer_flush(&s->sb);
 594         }
 595
 596     }
 597
 598     emms_c();
 599
 600     ff_snow_release_buffer(avctx);
 601
 602     if(!(s->avctx->debug&2048))
 603         res = av_frame_ref(picture, s->current_picture);
 604     else
 605         res = av_frame_ref(picture, s->mconly_picture);
 606     if (res >= 0 && s->avmv_index) {
 607         AVFrameSideData *sd;
 608
 609         sd = av_frame_new_side_data(picture, AV_FRAME_DATA_MOTION_VECTORS, s->avmv_index * sizeof(AVMotionVector));
 610         if (!sd)
 611             return AVERROR(ENOMEM);
 612         memcpy(sd->data, s->avmv, s->avmv_index * sizeof(AVMotionVector));
 613     }
 614
 615     av_freep(&s->avmv);
 616
 617     if (res < 0)
 618         return res;
 619
 620     *got_frame = 1;
 621
 622     bytes_read= c->bytestream - c->bytestream_start;
 623     if(bytes_read ==0) av_log(s->avctx, AV_LOG_ERROR, "error at end of frame\n"); //FIXME
 624
 625     return bytes_read;
 626 }
 627
 628 static av_cold int decode_end(AVCodecContext *avctx)
 629 {
 630     SnowContext *s = avctx->priv_data;
 631
 632     ff_slice_buffer_destroy(&s->sb);
 633
 634     ff_snow_common_end(s);
 635
 636     return 0;
 637 }
 638
 639 AVCodec ff_snow_decoder = {
 640     .name           = "snow",
 641     .long_name      = NULL_IF_CONFIG_SMALL("Snow"),
 642     .type           = AVMEDIA_TYPE_VIDEO,
 643     .id             = AV_CODEC_ID_SNOW,
 644     .priv_data_size = sizeof(SnowContext),
 645     .init           = decode_init,
 646     .close          = decode_end,
 647     .decode         = decode_frame,
 648     .capabilities   = AV_CODEC_CAP_DR1 /*| AV_CODEC_CAP_DRAW_HORIZ_BAND*/,
 649     .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE |
 650                       FF_CODEC_CAP_INIT_CLEANUP,
 651 };