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 "dsputil.h"
  26 #include "dwt.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 #undef NDEBUG
  36 #include <assert.h>
  37
  38 static av_always_inline void predict_slice_buffered(SnowContext *s, slice_buffer * sb, IDWTELEM * old_buffer, int plane_index, int add, int mb_y){
  39     Plane *p= &s->plane[plane_index];
  40     const int mb_w= s->b_width  << s->block_max_depth;
  41     const int mb_h= s->b_height << s->block_max_depth;
  42     int x, y, mb_x;
  43     int block_size = MB_SIZE >> s->block_max_depth;
  44     int block_w    = plane_index ? block_size>>s->chroma_h_shift : block_size;
  45     int block_h    = plane_index ? block_size>>s->chroma_v_shift : block_size;
  46     const uint8_t *obmc  = plane_index ? ff_obmc_tab[s->block_max_depth+s->chroma_h_shift] : ff_obmc_tab[s->block_max_depth];
  47     int obmc_stride= plane_index ? (2*block_size)>>s->chroma_h_shift : 2*block_size;
  48     int ref_stride= s->current_picture.linesize[plane_index];
  49     uint8_t *dst8= s->current_picture.data[plane_index];
  50     int w= p->width;
  51     int h= p->height;
  52
  53     if(s->keyframe || (s->avctx->debug&512)){
  54         if(mb_y==mb_h)
  55             return;
  56
  57         if(add){
  58             for(y=block_h*mb_y; y<FFMIN(h,block_h*(mb_y+1)); y++){
  59 //                DWTELEM * line = slice_buffer_get_line(sb, y);
  60                 IDWTELEM * line = sb->line[y];
  61                 for(x=0; x<w; x++){
  62 //                    int v= buf[x + y*w] + (128<<FRAC_BITS) + (1<<(FRAC_BITS-1));
  63                     int v= line[x] + (128<<FRAC_BITS) + (1<<(FRAC_BITS-1));
  64                     v >>= FRAC_BITS;
  65                     if(v&(~255)) v= ~(v>>31);
  66                     dst8[x + y*ref_stride]= v;
  67                 }
  68             }
  69         }else{
  70             for(y=block_h*mb_y; y<FFMIN(h,block_h*(mb_y+1)); y++){
  71 //                DWTELEM * line = slice_buffer_get_line(sb, y);
  72                 IDWTELEM * line = sb->line[y];
  73                 for(x=0; x<w; x++){
  74                     line[x] -= 128 << FRAC_BITS;
  75 //                    buf[x + y*w]-= 128<<FRAC_BITS;
  76                 }
  77             }
  78         }
  79
  80         return;
  81     }
  82
  83     for(mb_x=0; mb_x<=mb_w; mb_x++){
  84         add_yblock(s, 1, sb, old_buffer, dst8, obmc,
  85                    block_w*mb_x - block_w/2,
  86                    block_h*mb_y - block_h/2,
  87                    block_w, block_h,
  88                    w, h,
  89                    w, ref_stride, obmc_stride,
  90                    mb_x - 1, mb_y - 1,
  91                    add, 0, plane_index);
  92     }
  93 }
  94
  95 static inline void decode_subband_slice_buffered(SnowContext *s, SubBand *b, slice_buffer * sb, int start_y, int h, int save_state[1]){
  96     const int w= b->width;
  97     int y;
  98     const int qlog= av_clip(s->qlog + b->qlog, 0, QROOT*16);
  99     int qmul= ff_qexp[qlog&(QROOT-1)]<<(qlog>>QSHIFT);
 100     int qadd= (s->qbias*qmul)>>QBIAS_SHIFT;
 101     int new_index = 0;
 102
 103     if(b->ibuf == s->spatial_idwt_buffer || s->qlog == LOSSLESS_QLOG){
 104         qadd= 0;
 105         qmul= 1<<QEXPSHIFT;
 106     }
 107
 108     /* If we are on the second or later slice, restore our index. */
 109     if (start_y != 0)
 110         new_index = save_state[0];
 111
 112
 113     for(y=start_y; y<h; y++){
 114         int x = 0;
 115         int v;
 116         IDWTELEM * line = slice_buffer_get_line(sb, y * b->stride_line + b->buf_y_offset) + b->buf_x_offset;
 117         memset(line, 0, b->width*sizeof(IDWTELEM));
 118         v = b->x_coeff[new_index].coeff;
 119         x = b->x_coeff[new_index++].x;
 120         while(x < w){
 121             register int t= ( (v>>1)*qmul + qadd)>>QEXPSHIFT;
 122             register int u= -(v&1);
 123             line[x] = (t^u) - u;
 124
 125             v = b->x_coeff[new_index].coeff;
 126             x = b->x_coeff[new_index++].x;
 127         }
 128     }
 129
 130     /* Save our variables for the next slice. */
 131     save_state[0] = new_index;
 132
 133     return;
 134 }
 135
 136 static int decode_q_branch(SnowContext *s, int level, int x, int y){
 137     const int w= s->b_width << s->block_max_depth;
 138     const int rem_depth= s->block_max_depth - level;
 139     const int index= (x + y*w) << rem_depth;
 140     int trx= (x+1)<<rem_depth;
 141     const BlockNode *left  = x ? &s->block[index-1] : &null_block;
 142     const BlockNode *top   = y ? &s->block[index-w] : &null_block;
 143     const BlockNode *tl    = y && x ? &s->block[index-w-1] : left;
 144     const BlockNode *tr    = y && trx<w && ((x&1)==0 || level==0) ? &s->block[index-w+(1<<rem_depth)] : tl; //FIXME use lt
 145     int s_context= 2*left->level + 2*top->level + tl->level + tr->level;
 146     int res;
 147
 148     if(s->keyframe){
 149         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);
 150         return 0;
 151     }
 152
 153     if(level==s->block_max_depth || get_rac(&s->c, &s->block_state[4 + s_context])){
 154         int type, mx, my;
 155         int l = left->color[0];
 156         int cb= left->color[1];
 157         int cr= left->color[2];
 158         int ref = 0;
 159         int ref_context= av_log2(2*left->ref) + av_log2(2*top->ref);
 160         int mx_context= av_log2(2*FFABS(left->mx - top->mx)) + 0*av_log2(2*FFABS(tr->mx - top->mx));
 161         int my_context= av_log2(2*FFABS(left->my - top->my)) + 0*av_log2(2*FFABS(tr->my - top->my));
 162
 163         type= get_rac(&s->c, &s->block_state[1 + left->type + top->type]) ? BLOCK_INTRA : 0;
 164
 165         if(type){
 166             pred_mv(s, &mx, &my, 0, left, top, tr);
 167             l += get_symbol(&s->c, &s->block_state[32], 1);
 168             cb+= get_symbol(&s->c, &s->block_state[64], 1);
 169             cr+= get_symbol(&s->c, &s->block_state[96], 1);
 170         }else{
 171             if(s->ref_frames > 1)
 172                 ref= get_symbol(&s->c, &s->block_state[128 + 1024 + 32*ref_context], 0);
 173             if (ref >= s->ref_frames) {
 174                 av_log(s->avctx, AV_LOG_ERROR, "Invalid ref\n");
 175                 return AVERROR_INVALIDDATA;
 176             }
 177             pred_mv(s, &mx, &my, ref, left, top, tr);
 178             mx+= get_symbol(&s->c, &s->block_state[128 + 32*(mx_context + 16*!!ref)], 1);
 179             my+= get_symbol(&s->c, &s->block_state[128 + 32*(my_context + 16*!!ref)], 1);
 180         }
 181         set_blocks(s, level, x, y, l, cb, cr, mx, my, ref, type);
 182     }else{
 183         if ((res = decode_q_branch(s, level+1, 2*x+0, 2*y+0)) < 0 ||
 184             (res = decode_q_branch(s, level+1, 2*x+1, 2*y+0)) < 0 ||
 185             (res = decode_q_branch(s, level+1, 2*x+0, 2*y+1)) < 0 ||
 186             (res = decode_q_branch(s, level+1, 2*x+1, 2*y+1)) < 0)
 187             return res;
 188     }
 189     return 0;
 190 }
 191
 192 static void dequantize_slice_buffered(SnowContext *s, slice_buffer * sb, SubBand *b, IDWTELEM *src, int stride, int start_y, int end_y){
 193     const int w= b->width;
 194     const int qlog= av_clip(s->qlog + b->qlog, 0, QROOT*16);
 195     const int qmul= ff_qexp[qlog&(QROOT-1)]<<(qlog>>QSHIFT);
 196     const int qadd= (s->qbias*qmul)>>QBIAS_SHIFT;
 197     int x,y;
 198
 199     if(s->qlog == LOSSLESS_QLOG) return;
 200
 201     for(y=start_y; y<end_y; y++){
 202 //        DWTELEM * line = slice_buffer_get_line_from_address(sb, src + (y * stride));
 203         IDWTELEM * line = slice_buffer_get_line(sb, (y * b->stride_line) + b->buf_y_offset) + b->buf_x_offset;
 204         for(x=0; x<w; x++){
 205             int i= line[x];
 206             if(i<0){
 207                 line[x]= -((-i*qmul + qadd)>>(QEXPSHIFT)); //FIXME try different bias
 208             }else if(i>0){
 209                 line[x]=  (( i*qmul + qadd)>>(QEXPSHIFT));
 210             }
 211         }
 212     }
 213 }
 214
 215 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){
 216     const int w= b->width;
 217     int x,y;
 218
 219     IDWTELEM * line=0; // silence silly "could be used without having been initialized" warning
 220     IDWTELEM * prev;
 221
 222     if (start_y != 0)
 223         line = slice_buffer_get_line(sb, ((start_y - 1) * b->stride_line) + b->buf_y_offset) + b->buf_x_offset;
 224
 225     for(y=start_y; y<end_y; y++){
 226         prev = line;
 227 //        line = slice_buffer_get_line_from_address(sb, src + (y * stride));
 228         line = slice_buffer_get_line(sb, (y * b->stride_line) + b->buf_y_offset) + b->buf_x_offset;
 229         for(x=0; x<w; x++){
 230             if(x){
 231                 if(use_median){
 232                     if(y && x+1<w) line[x] += mid_pred(line[x - 1], prev[x], prev[x + 1]);
 233                     else  line[x] += line[x - 1];
 234                 }else{
 235                     if(y) line[x] += mid_pred(line[x - 1], prev[x], line[x - 1] + prev[x] - prev[x - 1]);
 236                     else  line[x] += line[x - 1];
 237                 }
 238             }else{
 239                 if(y) line[x] += prev[x];
 240             }
 241         }
 242     }
 243 }
 244
 245 static void decode_qlogs(SnowContext *s){
 246     int plane_index, level, orientation;
 247
 248     for(plane_index=0; plane_index<3; plane_index++){
 249         for(level=0; level<s->spatial_decomposition_count; level++){
 250             for(orientation=level ? 1:0; orientation<4; orientation++){
 251                 int q;
 252                 if     (plane_index==2) q= s->plane[1].band[level][orientation].qlog;
 253                 else if(orientation==2) q= s->plane[plane_index].band[level][1].qlog;
 254                 else                    q= get_symbol(&s->c, s->header_state, 1);
 255                 s->plane[plane_index].band[level][orientation].qlog= q;
 256             }
 257         }
 258     }
 259 }
 260
 261 #define GET_S(dst, check) \
 262     tmp= get_symbol(&s->c, s->header_state, 0);\
 263     if(!(check)){\
 264         av_log(s->avctx, AV_LOG_ERROR, "Error " #dst " is %d\n", tmp);\
 265         return -1;\
 266     }\
 267     dst= tmp;
 268
 269 static int decode_header(SnowContext *s){
 270     int plane_index, tmp;
 271     uint8_t kstate[32];
 272
 273     memset(kstate, MID_STATE, sizeof(kstate));
 274
 275     s->keyframe= get_rac(&s->c, kstate);
 276     if(s->keyframe || s->always_reset){
 277         ff_snow_reset_contexts(s);
 278         s->spatial_decomposition_type=
 279         s->qlog=
 280         s->qbias=
 281         s->mv_scale=
 282         s->block_max_depth= 0;
 283     }
 284     if(s->keyframe){
 285         GET_S(s->version, tmp <= 0U)
 286         s->always_reset= get_rac(&s->c, s->header_state);
 287         s->temporal_decomposition_type= get_symbol(&s->c, s->header_state, 0);
 288         s->temporal_decomposition_count= get_symbol(&s->c, s->header_state, 0);
 289         GET_S(s->spatial_decomposition_count, 0 < tmp && tmp <= MAX_DECOMPOSITIONS)
 290         s->colorspace_type= get_symbol(&s->c, s->header_state, 0);
 291         s->chroma_h_shift= get_symbol(&s->c, s->header_state, 0);
 292         s->chroma_v_shift= get_symbol(&s->c, s->header_state, 0);
 293
 294         if(s->chroma_h_shift == 1 && s->chroma_v_shift==1){
 295             s->avctx->pix_fmt= PIX_FMT_YUV420P;
 296         }else if(s->chroma_h_shift == 0 && s->chroma_v_shift==0){
 297             s->avctx->pix_fmt= PIX_FMT_YUV444P;
 298         }else if(s->chroma_h_shift == 2 && s->chroma_v_shift==2){
 299             s->avctx->pix_fmt= PIX_FMT_YUV410P;
 300         } else {
 301             av_log(s, AV_LOG_ERROR, "unsupported color subsample mode %d %d\n", s->chroma_h_shift, s->chroma_v_shift);
 302             s->chroma_h_shift = s->chroma_v_shift = 1;
 303             s->avctx->pix_fmt= PIX_FMT_YUV420P;
 304             return AVERROR_INVALIDDATA;
 305         }
 306
 307         s->spatial_scalability= get_rac(&s->c, s->header_state);
 308 //        s->rate_scalability= get_rac(&s->c, s->header_state);
 309         GET_S(s->max_ref_frames, tmp < (unsigned)MAX_REF_FRAMES)
 310         s->max_ref_frames++;
 311
 312         decode_qlogs(s);
 313     }
 314
 315     if(!s->keyframe){
 316         if(get_rac(&s->c, s->header_state)){
 317             for(plane_index=0; plane_index<2; plane_index++){
 318                 int htaps, i, sum=0;
 319                 Plane *p= &s->plane[plane_index];
 320                 p->diag_mc= get_rac(&s->c, s->header_state);
 321                 htaps= get_symbol(&s->c, s->header_state, 0)*2 + 2;
 322                 if((unsigned)htaps > HTAPS_MAX || htaps==0)
 323                     return -1;
 324                 p->htaps= htaps;
 325                 for(i= htaps/2; i; i--){
 326                     p->hcoeff[i]= get_symbol(&s->c, s->header_state, 0) * (1-2*(i&1));
 327                     sum += p->hcoeff[i];
 328                 }
 329                 p->hcoeff[0]= 32-sum;
 330             }
 331             s->plane[2].diag_mc= s->plane[1].diag_mc;
 332             s->plane[2].htaps  = s->plane[1].htaps;
 333             memcpy(s->plane[2].hcoeff, s->plane[1].hcoeff, sizeof(s->plane[1].hcoeff));
 334         }
 335         if(get_rac(&s->c, s->header_state)){
 336             GET_S(s->spatial_decomposition_count, 0 < tmp && tmp <= MAX_DECOMPOSITIONS)
 337             decode_qlogs(s);
 338         }
 339     }
 340
 341     s->spatial_decomposition_type+= get_symbol(&s->c, s->header_state, 1);
 342     if(s->spatial_decomposition_type > 1U){
 343         av_log(s->avctx, AV_LOG_ERROR, "spatial_decomposition_type %d not supported\n", s->spatial_decomposition_type);
 344         return -1;
 345     }
 346     if(FFMIN(s->avctx-> width>>s->chroma_h_shift,
 347              s->avctx->height>>s->chroma_v_shift) >> (s->spatial_decomposition_count-1) <= 0){
 348         av_log(s->avctx, AV_LOG_ERROR, "spatial_decomposition_count %d too large for size\n", s->spatial_decomposition_count);
 349         return -1;
 350     }
 351
 352
 353     s->qlog           += get_symbol(&s->c, s->header_state, 1);
 354     s->mv_scale       += get_symbol(&s->c, s->header_state, 1);
 355     s->qbias          += get_symbol(&s->c, s->header_state, 1);
 356     s->block_max_depth+= get_symbol(&s->c, s->header_state, 1);
 357     if(s->block_max_depth > 1 || s->block_max_depth < 0){
 358         av_log(s->avctx, AV_LOG_ERROR, "block_max_depth= %d is too large\n", s->block_max_depth);
 359         s->block_max_depth= 0;
 360         return -1;
 361     }
 362
 363     return 0;
 364 }
 365
 366 static av_cold int decode_init(AVCodecContext *avctx)
 367 {
 368     int ret;
 369
 370     if ((ret = ff_snow_common_init(avctx)) < 0) {
 371         ff_snow_common_end(avctx->priv_data);
 372         return ret;
 373     }
 374
 375     return 0;
 376 }
 377
 378 static int decode_blocks(SnowContext *s){
 379     int x, y;
 380     int w= s->b_width;
 381     int h= s->b_height;
 382     int res;
 383
 384     for(y=0; y<h; y++){
 385         for(x=0; x<w; x++){
 386             if ((res = decode_q_branch(s, 0, x, y)) < 0)
 387                 return res;
 388         }
 389     }
 390     return 0;
 391 }
 392
 393 static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt){
 394     const uint8_t *buf = avpkt->data;
 395     int buf_size = avpkt->size;
 396     SnowContext *s = avctx->priv_data;
 397     RangeCoder * const c= &s->c;
 398     int bytes_read;
 399     AVFrame *picture = data;
 400     int level, orientation, plane_index;
 401     int res;
 402
 403     ff_init_range_decoder(c, buf, buf_size);
 404     ff_build_rac_states(c, 0.05*(1LL<<32), 256-8);
 405
 406     s->current_picture.pict_type= AV_PICTURE_TYPE_I; //FIXME I vs. P
 407     if(decode_header(s)<0)
 408         return -1;
 409     if ((res=ff_snow_common_init_after_header(avctx)) < 0)
 410         return res;
 411
 412     // realloc slice buffer for the case that spatial_decomposition_count changed
 413     ff_slice_buffer_destroy(&s->sb);
 414     if ((res = ff_slice_buffer_init(&s->sb, s->plane[0].height,
 415                                     (MB_SIZE >> s->block_max_depth) +
 416                                     s->spatial_decomposition_count * 8 + 1,
 417                                     s->plane[0].width,
 418                                     s->spatial_idwt_buffer)) < 0)
 419         return res;
 420
 421     for(plane_index=0; plane_index<3; plane_index++){
 422         Plane *p= &s->plane[plane_index];
 423         p->fast_mc= p->diag_mc && p->htaps==6 && p->hcoeff[0]==40
 424                                               && p->hcoeff[1]==-10
 425                                               && p->hcoeff[2]==2;
 426     }
 427
 428     ff_snow_alloc_blocks(s);
 429
 430     if(ff_snow_frame_start(s) < 0)
 431         return -1;
 432     //keyframe flag duplication mess FIXME
 433     if(avctx->debug&FF_DEBUG_PICT_INFO)
 434         av_log(avctx, AV_LOG_ERROR, "keyframe:%d qlog:%d\n", s->keyframe, s->qlog);
 435
 436     if ((res = decode_blocks(s)) < 0)
 437         return res;
 438
 439     for(plane_index=0; plane_index<3; plane_index++){
 440         Plane *p= &s->plane[plane_index];
 441         int w= p->width;
 442         int h= p->height;
 443         int x, y;
 444         int decode_state[MAX_DECOMPOSITIONS][4][1]; /* Stored state info for unpack_coeffs. 1 variable per instance. */
 445
 446         if(s->avctx->debug&2048){
 447             memset(s->spatial_dwt_buffer, 0, sizeof(DWTELEM)*w*h);
 448             predict_plane(s, s->spatial_idwt_buffer, plane_index, 1);
 449
 450             for(y=0; y<h; y++){
 451                 for(x=0; x<w; x++){
 452                     int v= s->current_picture.data[plane_index][y*s->current_picture.linesize[plane_index] + x];
 453                     s->mconly_picture.data[plane_index][y*s->mconly_picture.linesize[plane_index] + x]= v;
 454                 }
 455             }
 456         }
 457
 458         {
 459         for(level=0; level<s->spatial_decomposition_count; level++){
 460             for(orientation=level ? 1 : 0; orientation<4; orientation++){
 461                 SubBand *b= &p->band[level][orientation];
 462                 unpack_coeffs(s, b, b->parent, orientation);
 463             }
 464         }
 465         }
 466
 467         {
 468         const int mb_h= s->b_height << s->block_max_depth;
 469         const int block_size = MB_SIZE >> s->block_max_depth;
 470         const int block_w    = plane_index ? block_size>>s->chroma_h_shift : block_size;
 471         const int block_h    = plane_index ? block_size>>s->chroma_v_shift : block_size;
 472         int mb_y;
 473         DWTCompose cs[MAX_DECOMPOSITIONS];
 474         int yd=0, yq=0;
 475         int y;
 476         int end_y;
 477
 478         ff_spatial_idwt_buffered_init(cs, &s->sb, w, h, 1, s->spatial_decomposition_type, s->spatial_decomposition_count);
 479         for(mb_y=0; mb_y<=mb_h; mb_y++){
 480
 481             int slice_starty = block_h*mb_y;
 482             int slice_h = block_h*(mb_y+1);
 483
 484             if (!(s->keyframe || s->avctx->debug&512)){
 485                 slice_starty = FFMAX(0, slice_starty - (block_h >> 1));
 486                 slice_h -= (block_h >> 1);
 487             }
 488
 489             for(level=0; level<s->spatial_decomposition_count; level++){
 490                 for(orientation=level ? 1 : 0; orientation<4; orientation++){
 491                     SubBand *b= &p->band[level][orientation];
 492                     int start_y;
 493                     int end_y;
 494                     int our_mb_start = mb_y;
 495                     int our_mb_end = (mb_y + 1);
 496                     const int extra= 3;
 497                     start_y = (mb_y ? ((block_h * our_mb_start) >> (s->spatial_decomposition_count - level)) + s->spatial_decomposition_count - level + extra: 0);
 498                     end_y = (((block_h * our_mb_end) >> (s->spatial_decomposition_count - level)) + s->spatial_decomposition_count - level + extra);
 499                     if (!(s->keyframe || s->avctx->debug&512)){
 500                         start_y = FFMAX(0, start_y - (block_h >> (1+s->spatial_decomposition_count - level)));
 501                         end_y = FFMAX(0, end_y - (block_h >> (1+s->spatial_decomposition_count - level)));
 502                     }
 503                     start_y = FFMIN(b->height, start_y);
 504                     end_y = FFMIN(b->height, end_y);
 505
 506                     if (start_y != end_y){
 507                         if (orientation == 0){
 508                             SubBand * correlate_band = &p->band[0][0];
 509                             int correlate_end_y = FFMIN(b->height, end_y + 1);
 510                             int correlate_start_y = FFMIN(b->height, (start_y ? start_y + 1 : 0));
 511                             decode_subband_slice_buffered(s, correlate_band, &s->sb, correlate_start_y, correlate_end_y, decode_state[0][0]);
 512                             correlate_slice_buffered(s, &s->sb, correlate_band, correlate_band->ibuf, correlate_band->stride, 1, 0, correlate_start_y, correlate_end_y);
 513                             dequantize_slice_buffered(s, &s->sb, correlate_band, correlate_band->ibuf, correlate_band->stride, start_y, end_y);
 514                         }
 515                         else
 516                             decode_subband_slice_buffered(s, b, &s->sb, start_y, end_y, decode_state[level][orientation]);
 517                     }
 518                 }
 519             }
 520
 521             for(; yd<slice_h; yd+=4){
 522                 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);
 523             }
 524
 525             if(s->qlog == LOSSLESS_QLOG){
 526                 for(; yq<slice_h && yq<h; yq++){
 527                     IDWTELEM * line = slice_buffer_get_line(&s->sb, yq);
 528                     for(x=0; x<w; x++){
 529                         line[x] <<= FRAC_BITS;
 530                     }
 531                 }
 532             }
 533
 534             predict_slice_buffered(s, &s->sb, s->spatial_idwt_buffer, plane_index, 1, mb_y);
 535
 536             y = FFMIN(p->height, slice_starty);
 537             end_y = FFMIN(p->height, slice_h);
 538             while(y < end_y)
 539                 ff_slice_buffer_release(&s->sb, y++);
 540         }
 541
 542         ff_slice_buffer_flush(&s->sb);
 543         }
 544
 545     }
 546
 547     emms_c();
 548
 549     ff_snow_release_buffer(avctx);
 550
 551     if(!(s->avctx->debug&2048))
 552         *picture= s->current_picture;
 553     else
 554         *picture= s->mconly_picture;
 555
 556     *data_size = sizeof(AVFrame);
 557
 558     bytes_read= c->bytestream - c->bytestream_start;
 559     if(bytes_read ==0) av_log(s->avctx, AV_LOG_ERROR, "error at end of frame\n"); //FIXME
 560
 561     return bytes_read;
 562 }
 563
 564 static av_cold int decode_end(AVCodecContext *avctx)
 565 {
 566     SnowContext *s = avctx->priv_data;
 567
 568     ff_slice_buffer_destroy(&s->sb);
 569
 570     ff_snow_common_end(s);
 571
 572     return 0;
 573 }
 574
 575 AVCodec ff_snow_decoder = {
 576     .name           = "snow",
 577     .type           = AVMEDIA_TYPE_VIDEO,
 578     .id             = AV_CODEC_ID_SNOW,
 579     .priv_data_size = sizeof(SnowContext),
 580     .init           = decode_init,
 581     .close          = decode_end,
 582     .decode         = decode_frame,
 583     .capabilities   = CODEC_CAP_DR1 /*| CODEC_CAP_DRAW_HORIZ_BAND*/,
 584     .long_name      = NULL_IF_CONFIG_SMALL("Snow"),
 585 };