mov: parse custom "----" Metadata
[ffmpeg.git] / 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 * 11 + 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 };