avcodec/snowdec: remove assert.h include, its unused
[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 "snow_dwt.h"
27 #include "internal.h"
28 #include "snow.h"
29
30 #include "rangecoder.h"
31 #include "mathops.h"
32
33 #include "mpegvideo.h"
34 #include "h263.h"
35
36 static av_always_inline void predict_slice_buffered(SnowContext *s, slice_buffer * sb, IDWTELEM * old_buffer, int plane_index, int add, int mb_y){
37     Plane *p= &s->plane[plane_index];
38     const int mb_w= s->b_width  << s->block_max_depth;
39     const int mb_h= s->b_height << s->block_max_depth;
40     int x, y, mb_x;
41     int block_size = MB_SIZE >> s->block_max_depth;
42     int block_w    = plane_index ? block_size>>s->chroma_h_shift : block_size;
43     int block_h    = plane_index ? block_size>>s->chroma_v_shift : block_size;
44     const uint8_t *obmc  = plane_index ? ff_obmc_tab[s->block_max_depth+s->chroma_h_shift] : ff_obmc_tab[s->block_max_depth];
45     int obmc_stride= plane_index ? (2*block_size)>>s->chroma_h_shift : 2*block_size;
46     int ref_stride= s->current_picture.linesize[plane_index];
47     uint8_t *dst8= s->current_picture.data[plane_index];
48     int w= p->width;
49     int h= p->height;
50
51     if(s->keyframe || (s->avctx->debug&512)){
52         if(mb_y==mb_h)
53             return;
54
55         if(add){
56             for(y=block_h*mb_y; y<FFMIN(h,block_h*(mb_y+1)); y++){
57 //                DWTELEM * line = slice_buffer_get_line(sb, y);
58                 IDWTELEM * line = sb->line[y];
59                 for(x=0; x<w; x++){
60 //                    int v= buf[x + y*w] + (128<<FRAC_BITS) + (1<<(FRAC_BITS-1));
61                     int v= line[x] + (128<<FRAC_BITS) + (1<<(FRAC_BITS-1));
62                     v >>= FRAC_BITS;
63                     if(v&(~255)) v= ~(v>>31);
64                     dst8[x + y*ref_stride]= v;
65                 }
66             }
67         }else{
68             for(y=block_h*mb_y; y<FFMIN(h,block_h*(mb_y+1)); y++){
69 //                DWTELEM * line = slice_buffer_get_line(sb, y);
70                 IDWTELEM * line = sb->line[y];
71                 for(x=0; x<w; x++){
72                     line[x] -= 128 << FRAC_BITS;
73 //                    buf[x + y*w]-= 128<<FRAC_BITS;
74                 }
75             }
76         }
77
78         return;
79     }
80
81     for(mb_x=0; mb_x<=mb_w; mb_x++){
82         add_yblock(s, 1, sb, old_buffer, dst8, obmc,
83                    block_w*mb_x - block_w/2,
84                    block_h*mb_y - block_h/2,
85                    block_w, block_h,
86                    w, h,
87                    w, ref_stride, obmc_stride,
88                    mb_x - 1, mb_y - 1,
89                    add, 0, plane_index);
90     }
91 }
92
93 static inline void decode_subband_slice_buffered(SnowContext *s, SubBand *b, slice_buffer * sb, int start_y, int h, int save_state[1]){
94     const int w= b->width;
95     int y;
96     const int qlog= av_clip(s->qlog + b->qlog, 0, QROOT*16);
97     int qmul= ff_qexp[qlog&(QROOT-1)]<<(qlog>>QSHIFT);
98     int qadd= (s->qbias*qmul)>>QBIAS_SHIFT;
99     int new_index = 0;
100
101     if(b->ibuf == s->spatial_idwt_buffer || s->qlog == LOSSLESS_QLOG){
102         qadd= 0;
103         qmul= 1<<QEXPSHIFT;
104     }
105
106     /* If we are on the second or later slice, restore our index. */
107     if (start_y != 0)
108         new_index = save_state[0];
109
110
111     for(y=start_y; y<h; y++){
112         int x = 0;
113         int v;
114         IDWTELEM * line = slice_buffer_get_line(sb, y * b->stride_line + b->buf_y_offset) + b->buf_x_offset;
115         memset(line, 0, b->width*sizeof(IDWTELEM));
116         v = b->x_coeff[new_index].coeff;
117         x = b->x_coeff[new_index++].x;
118         while(x < w){
119             register int t= ( (v>>1)*qmul + qadd)>>QEXPSHIFT;
120             register int u= -(v&1);
121             line[x] = (t^u) - u;
122
123             v = b->x_coeff[new_index].coeff;
124             x = b->x_coeff[new_index++].x;
125         }
126     }
127
128     /* Save our variables for the next slice. */
129     save_state[0] = new_index;
130
131     return;
132 }
133
134 static int decode_q_branch(SnowContext *s, int level, int x, int y){
135     const int w= s->b_width << s->block_max_depth;
136     const int rem_depth= s->block_max_depth - level;
137     const int index= (x + y*w) << rem_depth;
138     int trx= (x+1)<<rem_depth;
139     const BlockNode *left  = x ? &s->block[index-1] : &null_block;
140     const BlockNode *top   = y ? &s->block[index-w] : &null_block;
141     const BlockNode *tl    = y && x ? &s->block[index-w-1] : left;
142     const BlockNode *tr    = y && trx<w && ((x&1)==0 || level==0) ? &s->block[index-w+(1<<rem_depth)] : tl; //FIXME use lt
143     int s_context= 2*left->level + 2*top->level + tl->level + tr->level;
144     int res;
145
146     if(s->keyframe){
147         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);
148         return 0;
149     }
150
151     if(level==s->block_max_depth || get_rac(&s->c, &s->block_state[4 + s_context])){
152         int type, mx, my;
153         int l = left->color[0];
154         int cb= left->color[1];
155         int cr= left->color[2];
156         int ref = 0;
157         int ref_context= av_log2(2*left->ref) + av_log2(2*top->ref);
158         int mx_context= av_log2(2*FFABS(left->mx - top->mx)) + 0*av_log2(2*FFABS(tr->mx - top->mx));
159         int my_context= av_log2(2*FFABS(left->my - top->my)) + 0*av_log2(2*FFABS(tr->my - top->my));
160
161         type= get_rac(&s->c, &s->block_state[1 + left->type + top->type]) ? BLOCK_INTRA : 0;
162
163         if(type){
164             pred_mv(s, &mx, &my, 0, left, top, tr);
165             l += get_symbol(&s->c, &s->block_state[32], 1);
166             cb+= get_symbol(&s->c, &s->block_state[64], 1);
167             cr+= get_symbol(&s->c, &s->block_state[96], 1);
168         }else{
169             if(s->ref_frames > 1)
170                 ref= get_symbol(&s->c, &s->block_state[128 + 1024 + 32*ref_context], 0);
171             if (ref >= s->ref_frames) {
172                 av_log(s->avctx, AV_LOG_ERROR, "Invalid ref\n");
173                 return AVERROR_INVALIDDATA;
174             }
175             pred_mv(s, &mx, &my, ref, left, top, tr);
176             mx+= get_symbol(&s->c, &s->block_state[128 + 32*(mx_context + 16*!!ref)], 1);
177             my+= get_symbol(&s->c, &s->block_state[128 + 32*(my_context + 16*!!ref)], 1);
178         }
179         set_blocks(s, level, x, y, l, cb, cr, mx, my, ref, type);
180     }else{
181         if ((res = decode_q_branch(s, level+1, 2*x+0, 2*y+0)) < 0 ||
182             (res = decode_q_branch(s, level+1, 2*x+1, 2*y+0)) < 0 ||
183             (res = decode_q_branch(s, level+1, 2*x+0, 2*y+1)) < 0 ||
184             (res = decode_q_branch(s, level+1, 2*x+1, 2*y+1)) < 0)
185             return res;
186     }
187     return 0;
188 }
189
190 static void dequantize_slice_buffered(SnowContext *s, slice_buffer * sb, SubBand *b, IDWTELEM *src, int stride, int start_y, int end_y){
191     const int w= b->width;
192     const int qlog= av_clip(s->qlog + b->qlog, 0, QROOT*16);
193     const int qmul= ff_qexp[qlog&(QROOT-1)]<<(qlog>>QSHIFT);
194     const int qadd= (s->qbias*qmul)>>QBIAS_SHIFT;
195     int x,y;
196
197     if(s->qlog == LOSSLESS_QLOG) return;
198
199     for(y=start_y; y<end_y; y++){
200 //        DWTELEM * line = slice_buffer_get_line_from_address(sb, src + (y * stride));
201         IDWTELEM * line = slice_buffer_get_line(sb, (y * b->stride_line) + b->buf_y_offset) + b->buf_x_offset;
202         for(x=0; x<w; x++){
203             int i= line[x];
204             if(i<0){
205                 line[x]= -((-i*qmul + qadd)>>(QEXPSHIFT)); //FIXME try different bias
206             }else if(i>0){
207                 line[x]=  (( i*qmul + qadd)>>(QEXPSHIFT));
208             }
209         }
210     }
211 }
212
213 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){
214     const int w= b->width;
215     int x,y;
216
217     IDWTELEM * line=0; // silence silly "could be used without having been initialized" warning
218     IDWTELEM * prev;
219
220     if (start_y != 0)
221         line = slice_buffer_get_line(sb, ((start_y - 1) * b->stride_line) + b->buf_y_offset) + b->buf_x_offset;
222
223     for(y=start_y; y<end_y; y++){
224         prev = line;
225 //        line = slice_buffer_get_line_from_address(sb, src + (y * stride));
226         line = slice_buffer_get_line(sb, (y * b->stride_line) + b->buf_y_offset) + b->buf_x_offset;
227         for(x=0; x<w; x++){
228             if(x){
229                 if(use_median){
230                     if(y && x+1<w) line[x] += mid_pred(line[x - 1], prev[x], prev[x + 1]);
231                     else  line[x] += line[x - 1];
232                 }else{
233                     if(y) line[x] += mid_pred(line[x - 1], prev[x], line[x - 1] + prev[x] - prev[x - 1]);
234                     else  line[x] += line[x - 1];
235                 }
236             }else{
237                 if(y) line[x] += prev[x];
238             }
239         }
240     }
241 }
242
243 static void decode_qlogs(SnowContext *s){
244     int plane_index, level, orientation;
245
246     for(plane_index=0; plane_index<3; plane_index++){
247         for(level=0; level<s->spatial_decomposition_count; level++){
248             for(orientation=level ? 1:0; orientation<4; orientation++){
249                 int q;
250                 if     (plane_index==2) q= s->plane[1].band[level][orientation].qlog;
251                 else if(orientation==2) q= s->plane[plane_index].band[level][1].qlog;
252                 else                    q= get_symbol(&s->c, s->header_state, 1);
253                 s->plane[plane_index].band[level][orientation].qlog= q;
254             }
255         }
256     }
257 }
258
259 #define GET_S(dst, check) \
260     tmp= get_symbol(&s->c, s->header_state, 0);\
261     if(!(check)){\
262         av_log(s->avctx, AV_LOG_ERROR, "Error " #dst " is %d\n", tmp);\
263         return -1;\
264     }\
265     dst= tmp;
266
267 static int decode_header(SnowContext *s){
268     int plane_index, tmp;
269     uint8_t kstate[32];
270
271     memset(kstate, MID_STATE, sizeof(kstate));
272
273     s->keyframe= get_rac(&s->c, kstate);
274     if(s->keyframe || s->always_reset){
275         ff_snow_reset_contexts(s);
276         s->spatial_decomposition_type=
277         s->qlog=
278         s->qbias=
279         s->mv_scale=
280         s->block_max_depth= 0;
281     }
282     if(s->keyframe){
283         GET_S(s->version, tmp <= 0U)
284         s->always_reset= get_rac(&s->c, s->header_state);
285         s->temporal_decomposition_type= get_symbol(&s->c, s->header_state, 0);
286         s->temporal_decomposition_count= get_symbol(&s->c, s->header_state, 0);
287         GET_S(s->spatial_decomposition_count, 0 < tmp && tmp <= MAX_DECOMPOSITIONS)
288         s->colorspace_type= get_symbol(&s->c, s->header_state, 0);
289         s->chroma_h_shift= get_symbol(&s->c, s->header_state, 0);
290         s->chroma_v_shift= get_symbol(&s->c, s->header_state, 0);
291
292         if(s->chroma_h_shift == 1 && s->chroma_v_shift==1){
293             s->avctx->pix_fmt= AV_PIX_FMT_YUV420P;
294         }else if(s->chroma_h_shift == 0 && s->chroma_v_shift==0){
295             s->avctx->pix_fmt= AV_PIX_FMT_YUV444P;
296         }else if(s->chroma_h_shift == 2 && s->chroma_v_shift==2){
297             s->avctx->pix_fmt= AV_PIX_FMT_YUV410P;
298         } else {
299             av_log(s, AV_LOG_ERROR, "unsupported color subsample mode %d %d\n", s->chroma_h_shift, s->chroma_v_shift);
300             s->chroma_h_shift = s->chroma_v_shift = 1;
301             s->avctx->pix_fmt= AV_PIX_FMT_YUV420P;
302             return AVERROR_INVALIDDATA;
303         }
304
305         s->spatial_scalability= get_rac(&s->c, s->header_state);
306 //        s->rate_scalability= get_rac(&s->c, s->header_state);
307         GET_S(s->max_ref_frames, tmp < (unsigned)MAX_REF_FRAMES)
308         s->max_ref_frames++;
309
310         decode_qlogs(s);
311     }
312
313     if(!s->keyframe){
314         if(get_rac(&s->c, s->header_state)){
315             for(plane_index=0; plane_index<2; plane_index++){
316                 int htaps, i, sum=0;
317                 Plane *p= &s->plane[plane_index];
318                 p->diag_mc= get_rac(&s->c, s->header_state);
319                 htaps= get_symbol(&s->c, s->header_state, 0)*2 + 2;
320                 if((unsigned)htaps > HTAPS_MAX || htaps==0)
321                     return -1;
322                 p->htaps= htaps;
323                 for(i= htaps/2; i; i--){
324                     p->hcoeff[i]= get_symbol(&s->c, s->header_state, 0) * (1-2*(i&1));
325                     sum += p->hcoeff[i];
326                 }
327                 p->hcoeff[0]= 32-sum;
328             }
329             s->plane[2].diag_mc= s->plane[1].diag_mc;
330             s->plane[2].htaps  = s->plane[1].htaps;
331             memcpy(s->plane[2].hcoeff, s->plane[1].hcoeff, sizeof(s->plane[1].hcoeff));
332         }
333         if(get_rac(&s->c, s->header_state)){
334             GET_S(s->spatial_decomposition_count, 0 < tmp && tmp <= MAX_DECOMPOSITIONS)
335             decode_qlogs(s);
336         }
337     }
338
339     s->spatial_decomposition_type+= get_symbol(&s->c, s->header_state, 1);
340     if(s->spatial_decomposition_type > 1U){
341         av_log(s->avctx, AV_LOG_ERROR, "spatial_decomposition_type %d not supported\n", s->spatial_decomposition_type);
342         return -1;
343     }
344     if(FFMIN(s->avctx-> width>>s->chroma_h_shift,
345              s->avctx->height>>s->chroma_v_shift) >> (s->spatial_decomposition_count-1) <= 1){
346         av_log(s->avctx, AV_LOG_ERROR, "spatial_decomposition_count %d too large for size\n", s->spatial_decomposition_count);
347         return -1;
348     }
349
350
351     s->qlog           += get_symbol(&s->c, s->header_state, 1);
352     s->mv_scale       += get_symbol(&s->c, s->header_state, 1);
353     s->qbias          += get_symbol(&s->c, s->header_state, 1);
354     s->block_max_depth+= get_symbol(&s->c, s->header_state, 1);
355     if(s->block_max_depth > 1 || s->block_max_depth < 0){
356         av_log(s->avctx, AV_LOG_ERROR, "block_max_depth= %d is too large\n", s->block_max_depth);
357         s->block_max_depth= 0;
358         return -1;
359     }
360
361     return 0;
362 }
363
364 static av_cold int decode_init(AVCodecContext *avctx)
365 {
366     int ret;
367
368     if ((ret = ff_snow_common_init(avctx)) < 0) {
369         ff_snow_common_end(avctx->priv_data);
370         return ret;
371     }
372
373     return 0;
374 }
375
376 static int decode_blocks(SnowContext *s){
377     int x, y;
378     int w= s->b_width;
379     int h= s->b_height;
380     int res;
381
382     for(y=0; y<h; y++){
383         for(x=0; x<w; x++){
384             if ((res = decode_q_branch(s, 0, x, y)) < 0)
385                 return res;
386         }
387     }
388     return 0;
389 }
390
391 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
392                         AVPacket *avpkt)
393 {
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_h    = plane_index ? block_size>>s->chroma_v_shift : block_size;
471         int mb_y;
472         DWTCompose cs[MAX_DECOMPOSITIONS];
473         int yd=0, yq=0;
474         int y;
475         int end_y;
476
477         ff_spatial_idwt_buffered_init(cs, &s->sb, w, h, 1, s->spatial_decomposition_type, s->spatial_decomposition_count);
478         for(mb_y=0; mb_y<=mb_h; mb_y++){
479
480             int slice_starty = block_h*mb_y;
481             int slice_h = block_h*(mb_y+1);
482
483             if (!(s->keyframe || s->avctx->debug&512)){
484                 slice_starty = FFMAX(0, slice_starty - (block_h >> 1));
485                 slice_h -= (block_h >> 1);
486             }
487
488             for(level=0; level<s->spatial_decomposition_count; level++){
489                 for(orientation=level ? 1 : 0; orientation<4; orientation++){
490                     SubBand *b= &p->band[level][orientation];
491                     int start_y;
492                     int end_y;
493                     int our_mb_start = mb_y;
494                     int our_mb_end = (mb_y + 1);
495                     const int extra= 3;
496                     start_y = (mb_y ? ((block_h * our_mb_start) >> (s->spatial_decomposition_count - level)) + s->spatial_decomposition_count - level + extra: 0);
497                     end_y = (((block_h * our_mb_end) >> (s->spatial_decomposition_count - level)) + s->spatial_decomposition_count - level + extra);
498                     if (!(s->keyframe || s->avctx->debug&512)){
499                         start_y = FFMAX(0, start_y - (block_h >> (1+s->spatial_decomposition_count - level)));
500                         end_y = FFMAX(0, end_y - (block_h >> (1+s->spatial_decomposition_count - level)));
501                     }
502                     start_y = FFMIN(b->height, start_y);
503                     end_y = FFMIN(b->height, end_y);
504
505                     if (start_y != end_y){
506                         if (orientation == 0){
507                             SubBand * correlate_band = &p->band[0][0];
508                             int correlate_end_y = FFMIN(b->height, end_y + 1);
509                             int correlate_start_y = FFMIN(b->height, (start_y ? start_y + 1 : 0));
510                             decode_subband_slice_buffered(s, correlate_band, &s->sb, correlate_start_y, correlate_end_y, decode_state[0][0]);
511                             correlate_slice_buffered(s, &s->sb, correlate_band, correlate_band->ibuf, correlate_band->stride, 1, 0, correlate_start_y, correlate_end_y);
512                             dequantize_slice_buffered(s, &s->sb, correlate_band, correlate_band->ibuf, correlate_band->stride, start_y, end_y);
513                         }
514                         else
515                             decode_subband_slice_buffered(s, b, &s->sb, start_y, end_y, decode_state[level][orientation]);
516                     }
517                 }
518             }
519
520             for(; yd<slice_h; yd+=4){
521                 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);
522             }
523
524             if(s->qlog == LOSSLESS_QLOG){
525                 for(; yq<slice_h && yq<h; yq++){
526                     IDWTELEM * line = slice_buffer_get_line(&s->sb, yq);
527                     for(x=0; x<w; x++){
528                         line[x] <<= FRAC_BITS;
529                     }
530                 }
531             }
532
533             predict_slice_buffered(s, &s->sb, s->spatial_idwt_buffer, plane_index, 1, mb_y);
534
535             y = FFMIN(p->height, slice_starty);
536             end_y = FFMIN(p->height, slice_h);
537             while(y < end_y)
538                 ff_slice_buffer_release(&s->sb, y++);
539         }
540
541         ff_slice_buffer_flush(&s->sb);
542         }
543
544     }
545
546     emms_c();
547
548     ff_snow_release_buffer(avctx);
549
550     if(!(s->avctx->debug&2048))
551         av_frame_ref(picture, &s->current_picture);
552     else
553         av_frame_ref(picture, &s->mconly_picture);
554
555     *got_frame = 1;
556
557     bytes_read= c->bytestream - c->bytestream_start;
558     if(bytes_read ==0) av_log(s->avctx, AV_LOG_ERROR, "error at end of frame\n"); //FIXME
559
560     return bytes_read;
561 }
562
563 static av_cold int decode_end(AVCodecContext *avctx)
564 {
565     SnowContext *s = avctx->priv_data;
566
567     ff_slice_buffer_destroy(&s->sb);
568
569     ff_snow_common_end(s);
570
571     return 0;
572 }
573
574 AVCodec ff_snow_decoder = {
575     .name           = "snow",
576     .type           = AVMEDIA_TYPE_VIDEO,
577     .id             = AV_CODEC_ID_SNOW,
578     .priv_data_size = sizeof(SnowContext),
579     .init           = decode_init,
580     .close          = decode_end,
581     .decode         = decode_frame,
582     .capabilities   = CODEC_CAP_DR1 /*| CODEC_CAP_DRAW_HORIZ_BAND*/,
583     .long_name      = NULL_IF_CONFIG_SMALL("Snow"),
584 };