avcodec/dump_extradata_bsf: don't allocate a new AVPacket per filtered packet
[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 "snow_dwt.h"
26 #include "internal.h"
27 #include "snow.h"
28
29 #include "rangecoder.h"
30 #include "mathops.h"
31
32 #include "mpegvideo.h"
33 #include "h263.h"
34
35 static av_always_inline void predict_slice_buffered(SnowContext *s, slice_buffer * sb, IDWTELEM * old_buffer, int plane_index, int add, int mb_y){
36     Plane *p= &s->plane[plane_index];
37     const int mb_w= s->b_width  << s->block_max_depth;
38     const int mb_h= s->b_height << s->block_max_depth;
39     int x, y, mb_x;
40     int block_size = MB_SIZE >> s->block_max_depth;
41     int block_w    = plane_index ? block_size>>s->chroma_h_shift : block_size;
42     int block_h    = plane_index ? block_size>>s->chroma_v_shift : block_size;
43     const uint8_t *obmc  = plane_index ? ff_obmc_tab[s->block_max_depth+s->chroma_h_shift] : ff_obmc_tab[s->block_max_depth];
44     int obmc_stride= plane_index ? (2*block_size)>>s->chroma_h_shift : 2*block_size;
45     int ref_stride= s->current_picture->linesize[plane_index];
46     uint8_t *dst8= s->current_picture->data[plane_index];
47     int w= p->width;
48     int h= p->height;
49
50     if(s->keyframe || (s->avctx->debug&512)){
51         if(mb_y==mb_h)
52             return;
53
54         if(add){
55             for(y=block_h*mb_y; y<FFMIN(h,block_h*(mb_y+1)); y++){
56 //                DWTELEM * line = slice_buffer_get_line(sb, y);
57                 IDWTELEM * line = sb->line[y];
58                 for(x=0; x<w; x++){
59 //                    int v= buf[x + y*w] + (128<<FRAC_BITS) + (1<<(FRAC_BITS-1));
60                     int v= line[x] + (128<<FRAC_BITS) + (1<<(FRAC_BITS-1));
61                     v >>= FRAC_BITS;
62                     if(v&(~255)) v= ~(v>>31);
63                     dst8[x + y*ref_stride]= v;
64                 }
65             }
66         }else{
67             for(y=block_h*mb_y; y<FFMIN(h,block_h*(mb_y+1)); y++){
68 //                DWTELEM * line = slice_buffer_get_line(sb, y);
69                 IDWTELEM * line = sb->line[y];
70                 for(x=0; x<w; x++){
71                     line[x] -= 128 << FRAC_BITS;
72 //                    buf[x + y*w]-= 128<<FRAC_BITS;
73                 }
74             }
75         }
76
77         return;
78     }
79
80     for(mb_x=0; mb_x<=mb_w; mb_x++){
81         add_yblock(s, 1, sb, old_buffer, dst8, obmc,
82                    block_w*mb_x - block_w/2,
83                    block_h*mb_y - block_h/2,
84                    block_w, block_h,
85                    w, h,
86                    w, ref_stride, obmc_stride,
87                    mb_x - 1, mb_y - 1,
88                    add, 0, plane_index);
89     }
90
91     if(s->avmv && mb_y < mb_h && plane_index == 0)
92         for(mb_x=0; mb_x<mb_w; mb_x++){
93             AVMotionVector *avmv = s->avmv + s->avmv_index;
94             const int b_width = s->b_width  << s->block_max_depth;
95             const int b_stride= b_width;
96             BlockNode *bn= &s->block[mb_x + mb_y*b_stride];
97
98             if (bn->type)
99                 continue;
100
101             s->avmv_index++;
102
103             avmv->w = block_w;
104             avmv->h = block_h;
105             avmv->dst_x = block_w*mb_x - block_w/2;
106             avmv->dst_y = block_h*mb_y - block_h/2;
107             avmv->motion_scale = 8;
108             avmv->motion_x = bn->mx * s->mv_scale;
109             avmv->motion_y = bn->my * s->mv_scale;
110             avmv->src_x = avmv->dst_x + avmv->motion_x / 8;
111             avmv->src_y = avmv->dst_y + avmv->motion_y / 8;
112             avmv->source= -1 - bn->ref;
113             avmv->flags = 0;
114         }
115 }
116
117 static inline void decode_subband_slice_buffered(SnowContext *s, SubBand *b, slice_buffer * sb, int start_y, int h, int save_state[1]){
118     const int w= b->width;
119     int y;
120     const int qlog= av_clip(s->qlog + b->qlog, 0, QROOT*16);
121     int qmul= ff_qexp[qlog&(QROOT-1)]<<(qlog>>QSHIFT);
122     int qadd= (s->qbias*qmul)>>QBIAS_SHIFT;
123     int new_index = 0;
124
125     if(b->ibuf == s->spatial_idwt_buffer || s->qlog == LOSSLESS_QLOG){
126         qadd= 0;
127         qmul= 1<<QEXPSHIFT;
128     }
129
130     /* If we are on the second or later slice, restore our index. */
131     if (start_y != 0)
132         new_index = save_state[0];
133
134
135     for(y=start_y; y<h; y++){
136         int x = 0;
137         int v;
138         IDWTELEM * line = slice_buffer_get_line(sb, y * b->stride_line + b->buf_y_offset) + b->buf_x_offset;
139         memset(line, 0, b->width*sizeof(IDWTELEM));
140         v = b->x_coeff[new_index].coeff;
141         x = b->x_coeff[new_index++].x;
142         while(x < w){
143             register int t= (int)( (v>>1)*(unsigned)qmul + qadd)>>QEXPSHIFT;
144             register int u= -(v&1);
145             line[x] = (t^u) - u;
146
147             v = b->x_coeff[new_index].coeff;
148             x = b->x_coeff[new_index++].x;
149         }
150     }
151
152     /* Save our variables for the next slice. */
153     save_state[0] = new_index;
154
155     return;
156 }
157
158 static int decode_q_branch(SnowContext *s, int level, int x, int y){
159     const int w= s->b_width << s->block_max_depth;
160     const int rem_depth= s->block_max_depth - level;
161     const int index= (x + y*w) << rem_depth;
162     int trx= (x+1)<<rem_depth;
163     const BlockNode *left  = x ? &s->block[index-1] : &null_block;
164     const BlockNode *top   = y ? &s->block[index-w] : &null_block;
165     const BlockNode *tl    = y && x ? &s->block[index-w-1] : left;
166     const BlockNode *tr    = y && trx<w && ((x&1)==0 || level==0) ? &s->block[index-w+(1<<rem_depth)] : tl; //FIXME use lt
167     int s_context= 2*left->level + 2*top->level + tl->level + tr->level;
168     int res;
169
170     if(s->keyframe){
171         set_blocks(s, level, x, y, null_block.color[0], null_block.color[1], null_block.color[2], null_block.mx, null_block.my, null_block.ref, BLOCK_INTRA);
172         return 0;
173     }
174
175     if(level==s->block_max_depth || get_rac(&s->c, &s->block_state[4 + s_context])){
176         int type, mx, my;
177         int l = left->color[0];
178         int cb= left->color[1];
179         int cr= left->color[2];
180         unsigned ref = 0;
181         int ref_context= av_log2(2*left->ref) + av_log2(2*top->ref);
182         int mx_context= av_log2(2*FFABS(left->mx - top->mx)) + 0*av_log2(2*FFABS(tr->mx - top->mx));
183         int my_context= av_log2(2*FFABS(left->my - top->my)) + 0*av_log2(2*FFABS(tr->my - top->my));
184
185         type= get_rac(&s->c, &s->block_state[1 + left->type + top->type]) ? BLOCK_INTRA : 0;
186         if(type){
187             int ld, cbd, crd;
188             pred_mv(s, &mx, &my, 0, left, top, tr);
189             ld = get_symbol(&s->c, &s->block_state[32], 1);
190             if (ld < -255 || ld > 255) {
191                 return AVERROR_INVALIDDATA;
192             }
193             l += ld;
194             if (s->nb_planes > 2) {
195                 cbd = get_symbol(&s->c, &s->block_state[64], 1);
196                 crd = get_symbol(&s->c, &s->block_state[96], 1);
197                 if (cbd < -255 || cbd > 255 || crd < -255 || crd > 255) {
198                     return AVERROR_INVALIDDATA;
199                 }
200                 cb += cbd;
201                 cr += crd;
202             }
203         }else{
204             if(s->ref_frames > 1)
205                 ref= get_symbol(&s->c, &s->block_state[128 + 1024 + 32*ref_context], 0);
206             if (ref >= s->ref_frames) {
207                 av_log(s->avctx, AV_LOG_ERROR, "Invalid ref\n");
208                 return AVERROR_INVALIDDATA;
209             }
210             pred_mv(s, &mx, &my, ref, left, top, tr);
211             mx+= get_symbol(&s->c, &s->block_state[128 + 32*(mx_context + 16*!!ref)], 1);
212             my+= get_symbol(&s->c, &s->block_state[128 + 32*(my_context + 16*!!ref)], 1);
213         }
214         set_blocks(s, level, x, y, l, cb, cr, mx, my, ref, type);
215     }else{
216         if ((res = decode_q_branch(s, level+1, 2*x+0, 2*y+0)) < 0 ||
217             (res = decode_q_branch(s, level+1, 2*x+1, 2*y+0)) < 0 ||
218             (res = decode_q_branch(s, level+1, 2*x+0, 2*y+1)) < 0 ||
219             (res = decode_q_branch(s, level+1, 2*x+1, 2*y+1)) < 0)
220             return res;
221     }
222     return 0;
223 }
224
225 static void dequantize_slice_buffered(SnowContext *s, slice_buffer * sb, SubBand *b, IDWTELEM *src, int stride, int start_y, int end_y){
226     const int w= b->width;
227     const int qlog= av_clip(s->qlog + b->qlog, 0, QROOT*16);
228     const int qmul= ff_qexp[qlog&(QROOT-1)]<<(qlog>>QSHIFT);
229     const int qadd= (s->qbias*qmul)>>QBIAS_SHIFT;
230     int x,y;
231
232     if(s->qlog == LOSSLESS_QLOG) return;
233
234     for(y=start_y; y<end_y; y++){
235 //        DWTELEM * line = slice_buffer_get_line_from_address(sb, src + (y * stride));
236         IDWTELEM * line = slice_buffer_get_line(sb, (y * b->stride_line) + b->buf_y_offset) + b->buf_x_offset;
237         for(x=0; x<w; x++){
238             int i= line[x];
239             if(i<0){
240                 line[x]= -((-i*(unsigned)qmul + qadd)>>(QEXPSHIFT)); //FIXME try different bias
241             }else if(i>0){
242                 line[x]=  (( i*(unsigned)qmul + qadd)>>(QEXPSHIFT));
243             }
244         }
245     }
246 }
247
248 static void correlate_slice_buffered(SnowContext *s, slice_buffer * sb, SubBand *b, IDWTELEM *src, int stride, int inverse, int use_median, int start_y, int end_y){
249     const int w= b->width;
250     int x,y;
251
252     IDWTELEM * line=0; // silence silly "could be used without having been initialized" warning
253     IDWTELEM * prev;
254
255     if (start_y != 0)
256         line = slice_buffer_get_line(sb, ((start_y - 1) * b->stride_line) + b->buf_y_offset) + b->buf_x_offset;
257
258     for(y=start_y; y<end_y; y++){
259         prev = line;
260 //        line = slice_buffer_get_line_from_address(sb, src + (y * stride));
261         line = slice_buffer_get_line(sb, (y * b->stride_line) + b->buf_y_offset) + b->buf_x_offset;
262         for(x=0; x<w; x++){
263             if(x){
264                 if(use_median){
265                     if(y && x+1<w) line[x] += mid_pred(line[x - 1], prev[x], prev[x + 1]);
266                     else  line[x] += line[x - 1];
267                 }else{
268                     if(y) line[x] += mid_pred(line[x - 1], prev[x], line[x - 1] + prev[x] - prev[x - 1]);
269                     else  line[x] += line[x - 1];
270                 }
271             }else{
272                 if(y) line[x] += prev[x];
273             }
274         }
275     }
276 }
277
278 static void decode_qlogs(SnowContext *s){
279     int plane_index, level, orientation;
280
281     for(plane_index=0; plane_index < s->nb_planes; plane_index++){
282         for(level=0; level<s->spatial_decomposition_count; level++){
283             for(orientation=level ? 1:0; orientation<4; orientation++){
284                 int q;
285                 if     (plane_index==2) q= s->plane[1].band[level][orientation].qlog;
286                 else if(orientation==2) q= s->plane[plane_index].band[level][1].qlog;
287                 else                    q= get_symbol(&s->c, s->header_state, 1);
288                 s->plane[plane_index].band[level][orientation].qlog= q;
289             }
290         }
291     }
292 }
293
294 #define GET_S(dst, check) \
295     tmp= get_symbol(&s->c, s->header_state, 0);\
296     if(!(check)){\
297         av_log(s->avctx, AV_LOG_ERROR, "Error " #dst " is %d\n", tmp);\
298         return AVERROR_INVALIDDATA;\
299     }\
300     dst= tmp;
301
302 static int decode_header(SnowContext *s){
303     int plane_index, tmp;
304     uint8_t kstate[32];
305
306     memset(kstate, MID_STATE, sizeof(kstate));
307
308     s->keyframe= get_rac(&s->c, kstate);
309     if(s->keyframe || s->always_reset){
310         ff_snow_reset_contexts(s);
311         s->spatial_decomposition_type=
312         s->qlog=
313         s->qbias=
314         s->mv_scale=
315         s->block_max_depth= 0;
316     }
317     if(s->keyframe){
318         GET_S(s->version, tmp <= 0U)
319         s->always_reset= get_rac(&s->c, s->header_state);
320         s->temporal_decomposition_type= get_symbol(&s->c, s->header_state, 0);
321         s->temporal_decomposition_count= get_symbol(&s->c, s->header_state, 0);
322         GET_S(s->spatial_decomposition_count, 0 < tmp && tmp <= MAX_DECOMPOSITIONS)
323         s->colorspace_type= get_symbol(&s->c, s->header_state, 0);
324         if (s->colorspace_type == 1) {
325             s->avctx->pix_fmt= AV_PIX_FMT_GRAY8;
326             s->nb_planes = 1;
327         } else if(s->colorspace_type == 0) {
328             s->chroma_h_shift= get_symbol(&s->c, s->header_state, 0);
329             s->chroma_v_shift= get_symbol(&s->c, s->header_state, 0);
330
331             if(s->chroma_h_shift == 1 && s->chroma_v_shift==1){
332                 s->avctx->pix_fmt= AV_PIX_FMT_YUV420P;
333             }else if(s->chroma_h_shift == 0 && s->chroma_v_shift==0){
334                 s->avctx->pix_fmt= AV_PIX_FMT_YUV444P;
335             }else if(s->chroma_h_shift == 2 && s->chroma_v_shift==2){
336                 s->avctx->pix_fmt= AV_PIX_FMT_YUV410P;
337             } else {
338                 av_log(s, AV_LOG_ERROR, "unsupported color subsample mode %d %d\n", s->chroma_h_shift, s->chroma_v_shift);
339                 s->chroma_h_shift = s->chroma_v_shift = 1;
340                 s->avctx->pix_fmt= AV_PIX_FMT_YUV420P;
341                 return AVERROR_INVALIDDATA;
342             }
343             s->nb_planes = 3;
344         } else {
345             av_log(s, AV_LOG_ERROR, "unsupported color space\n");
346             s->chroma_h_shift = s->chroma_v_shift = 1;
347             s->avctx->pix_fmt= AV_PIX_FMT_YUV420P;
348             return AVERROR_INVALIDDATA;
349         }
350
351
352         s->spatial_scalability= get_rac(&s->c, s->header_state);
353 //        s->rate_scalability= get_rac(&s->c, s->header_state);
354         GET_S(s->max_ref_frames, tmp < (unsigned)MAX_REF_FRAMES)
355         s->max_ref_frames++;
356
357         decode_qlogs(s);
358     }
359
360     if(!s->keyframe){
361         if(get_rac(&s->c, s->header_state)){
362             for(plane_index=0; plane_index<FFMIN(s->nb_planes, 2); plane_index++){
363                 int htaps, i, sum=0;
364                 Plane *p= &s->plane[plane_index];
365                 p->diag_mc= get_rac(&s->c, s->header_state);
366                 htaps= get_symbol(&s->c, s->header_state, 0);
367                 if((unsigned)htaps >= HTAPS_MAX/2 - 1)
368                     return AVERROR_INVALIDDATA;
369                 htaps = htaps*2 + 2;
370                 p->htaps= htaps;
371                 for(i= htaps/2; i; i--){
372                     p->hcoeff[i]= get_symbol(&s->c, s->header_state, 0) * (1-2*(i&1));
373                     sum += p->hcoeff[i];
374                 }
375                 p->hcoeff[0]= 32-sum;
376             }
377             s->plane[2].diag_mc= s->plane[1].diag_mc;
378             s->plane[2].htaps  = s->plane[1].htaps;
379             memcpy(s->plane[2].hcoeff, s->plane[1].hcoeff, sizeof(s->plane[1].hcoeff));
380         }
381         if(get_rac(&s->c, s->header_state)){
382             GET_S(s->spatial_decomposition_count, 0 < tmp && tmp <= MAX_DECOMPOSITIONS)
383             decode_qlogs(s);
384         }
385     }
386
387     s->spatial_decomposition_type+= (unsigned)get_symbol(&s->c, s->header_state, 1);
388     if(s->spatial_decomposition_type > 1U){
389         av_log(s->avctx, AV_LOG_ERROR, "spatial_decomposition_type %d not supported\n", s->spatial_decomposition_type);
390         return AVERROR_INVALIDDATA;
391     }
392     if(FFMIN(s->avctx-> width>>s->chroma_h_shift,
393              s->avctx->height>>s->chroma_v_shift) >> (s->spatial_decomposition_count-1) <= 1){
394         av_log(s->avctx, AV_LOG_ERROR, "spatial_decomposition_count %d too large for size\n", s->spatial_decomposition_count);
395         return AVERROR_INVALIDDATA;
396     }
397     if (s->avctx->width > 65536-4) {
398         av_log(s->avctx, AV_LOG_ERROR, "Width %d is too large\n", s->avctx->width);
399         return AVERROR_INVALIDDATA;
400     }
401
402
403     s->qlog           += (unsigned)get_symbol(&s->c, s->header_state, 1);
404     s->mv_scale       += (unsigned)get_symbol(&s->c, s->header_state, 1);
405     s->qbias          += (unsigned)get_symbol(&s->c, s->header_state, 1);
406     s->block_max_depth+= (unsigned)get_symbol(&s->c, s->header_state, 1);
407     if(s->block_max_depth > 1 || s->block_max_depth < 0 || s->mv_scale > 256U){
408         av_log(s->avctx, AV_LOG_ERROR, "block_max_depth= %d is too large\n", s->block_max_depth);
409         s->block_max_depth= 0;
410         s->mv_scale = 0;
411         return AVERROR_INVALIDDATA;
412     }
413     if (FFABS(s->qbias) > 127) {
414         av_log(s->avctx, AV_LOG_ERROR, "qbias %d is too large\n", s->qbias);
415         s->qbias = 0;
416         return AVERROR_INVALIDDATA;
417     }
418
419     return 0;
420 }
421
422 static av_cold int decode_init(AVCodecContext *avctx)
423 {
424     int ret;
425
426     if ((ret = ff_snow_common_init(avctx)) < 0) {
427         return ret;
428     }
429
430     return 0;
431 }
432
433 static int decode_blocks(SnowContext *s){
434     int x, y;
435     int w= s->b_width;
436     int h= s->b_height;
437     int res;
438
439     for(y=0; y<h; y++){
440         for(x=0; x<w; x++){
441             if (s->c.bytestream >= s->c.bytestream_end)
442                 return AVERROR_INVALIDDATA;
443             if ((res = decode_q_branch(s, 0, x, y)) < 0)
444                 return res;
445         }
446     }
447     return 0;
448 }
449
450 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
451                         AVPacket *avpkt)
452 {
453     const uint8_t *buf = avpkt->data;
454     int buf_size = avpkt->size;
455     SnowContext *s = avctx->priv_data;
456     RangeCoder * const c= &s->c;
457     int bytes_read;
458     AVFrame *picture = data;
459     int level, orientation, plane_index;
460     int res;
461
462     ff_init_range_decoder(c, buf, buf_size);
463     ff_build_rac_states(c, 0.05*(1LL<<32), 256-8);
464
465     s->current_picture->pict_type= AV_PICTURE_TYPE_I; //FIXME I vs. P
466     if ((res = decode_header(s)) < 0)
467         return res;
468     if ((res=ff_snow_common_init_after_header(avctx)) < 0)
469         return res;
470
471     // realloc slice buffer for the case that spatial_decomposition_count changed
472     ff_slice_buffer_destroy(&s->sb);
473     if ((res = ff_slice_buffer_init(&s->sb, s->plane[0].height,
474                                     (MB_SIZE >> s->block_max_depth) +
475                                     s->spatial_decomposition_count * 11 + 1,
476                                     s->plane[0].width,
477                                     s->spatial_idwt_buffer)) < 0)
478         return res;
479
480     for(plane_index=0; plane_index < s->nb_planes; plane_index++){
481         Plane *p= &s->plane[plane_index];
482         p->fast_mc= p->diag_mc && p->htaps==6 && p->hcoeff[0]==40
483                                               && p->hcoeff[1]==-10
484                                               && p->hcoeff[2]==2;
485     }
486
487     ff_snow_alloc_blocks(s);
488
489     if((res = ff_snow_frame_start(s)) < 0)
490         return res;
491
492     s->current_picture->pict_type = s->keyframe ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
493
494     //keyframe flag duplication mess FIXME
495     if(avctx->debug&FF_DEBUG_PICT_INFO)
496         av_log(avctx, AV_LOG_ERROR,
497                "keyframe:%d qlog:%d qbias: %d mvscale: %d "
498                "decomposition_type:%d decomposition_count:%d\n",
499                s->keyframe, s->qlog, s->qbias, s->mv_scale,
500                s->spatial_decomposition_type,
501                s->spatial_decomposition_count
502               );
503
504     av_assert0(!s->avmv);
505     if (s->avctx->flags2 & AV_CODEC_FLAG2_EXPORT_MVS) {
506         s->avmv = av_malloc_array(s->b_width * s->b_height, sizeof(AVMotionVector) << (s->block_max_depth*2));
507     }
508     s->avmv_index = 0;
509
510     if ((res = decode_blocks(s)) < 0)
511         return res;
512
513     for(plane_index=0; plane_index < s->nb_planes; plane_index++){
514         Plane *p= &s->plane[plane_index];
515         int w= p->width;
516         int h= p->height;
517         int x, y;
518         int decode_state[MAX_DECOMPOSITIONS][4][1]; /* Stored state info for unpack_coeffs. 1 variable per instance. */
519
520         if(s->avctx->debug&2048){
521             memset(s->spatial_dwt_buffer, 0, sizeof(DWTELEM)*w*h);
522             predict_plane(s, s->spatial_idwt_buffer, plane_index, 1);
523
524             for(y=0; y<h; y++){
525                 for(x=0; x<w; x++){
526                     int v= s->current_picture->data[plane_index][y*s->current_picture->linesize[plane_index] + x];
527                     s->mconly_picture->data[plane_index][y*s->mconly_picture->linesize[plane_index] + x]= v;
528                 }
529             }
530         }
531
532         for(level=0; level<s->spatial_decomposition_count; level++){
533             for(orientation=level ? 1 : 0; orientation<4; orientation++){
534                 SubBand *b= &p->band[level][orientation];
535                 unpack_coeffs(s, b, b->parent, orientation);
536             }
537         }
538
539         {
540         const int mb_h= s->b_height << s->block_max_depth;
541         const int block_size = MB_SIZE >> s->block_max_depth;
542         const int block_h    = plane_index ? block_size>>s->chroma_v_shift : block_size;
543         int mb_y;
544         DWTCompose cs[MAX_DECOMPOSITIONS];
545         int yd=0, yq=0;
546         int y;
547         int end_y;
548
549         ff_spatial_idwt_buffered_init(cs, &s->sb, w, h, 1, s->spatial_decomposition_type, s->spatial_decomposition_count);
550         for(mb_y=0; mb_y<=mb_h; mb_y++){
551
552             int slice_starty = block_h*mb_y;
553             int slice_h = block_h*(mb_y+1);
554
555             if (!(s->keyframe || s->avctx->debug&512)){
556                 slice_starty = FFMAX(0, slice_starty - (block_h >> 1));
557                 slice_h -= (block_h >> 1);
558             }
559
560             for(level=0; level<s->spatial_decomposition_count; level++){
561                 for(orientation=level ? 1 : 0; orientation<4; orientation++){
562                     SubBand *b= &p->band[level][orientation];
563                     int start_y;
564                     int end_y;
565                     int our_mb_start = mb_y;
566                     int our_mb_end = (mb_y + 1);
567                     const int extra= 3;
568                     start_y = (mb_y ? ((block_h * our_mb_start) >> (s->spatial_decomposition_count - level)) + s->spatial_decomposition_count - level + extra: 0);
569                     end_y = (((block_h * our_mb_end) >> (s->spatial_decomposition_count - level)) + s->spatial_decomposition_count - level + extra);
570                     if (!(s->keyframe || s->avctx->debug&512)){
571                         start_y = FFMAX(0, start_y - (block_h >> (1+s->spatial_decomposition_count - level)));
572                         end_y = FFMAX(0, end_y - (block_h >> (1+s->spatial_decomposition_count - level)));
573                     }
574                     start_y = FFMIN(b->height, start_y);
575                     end_y = FFMIN(b->height, end_y);
576
577                     if (start_y != end_y){
578                         if (orientation == 0){
579                             SubBand * correlate_band = &p->band[0][0];
580                             int correlate_end_y = FFMIN(b->height, end_y + 1);
581                             int correlate_start_y = FFMIN(b->height, (start_y ? start_y + 1 : 0));
582                             decode_subband_slice_buffered(s, correlate_band, &s->sb, correlate_start_y, correlate_end_y, decode_state[0][0]);
583                             correlate_slice_buffered(s, &s->sb, correlate_band, correlate_band->ibuf, correlate_band->stride, 1, 0, correlate_start_y, correlate_end_y);
584                             dequantize_slice_buffered(s, &s->sb, correlate_band, correlate_band->ibuf, correlate_band->stride, start_y, end_y);
585                         }
586                         else
587                             decode_subband_slice_buffered(s, b, &s->sb, start_y, end_y, decode_state[level][orientation]);
588                     }
589                 }
590             }
591
592             for(; yd<slice_h; yd+=4){
593                 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);
594             }
595
596             if(s->qlog == LOSSLESS_QLOG){
597                 for(; yq<slice_h && yq<h; yq++){
598                     IDWTELEM * line = slice_buffer_get_line(&s->sb, yq);
599                     for(x=0; x<w; x++){
600                         line[x] *= 1<<FRAC_BITS;
601                     }
602                 }
603             }
604
605             predict_slice_buffered(s, &s->sb, s->spatial_idwt_buffer, plane_index, 1, mb_y);
606
607             y = FFMIN(p->height, slice_starty);
608             end_y = FFMIN(p->height, slice_h);
609             while(y < end_y)
610                 ff_slice_buffer_release(&s->sb, y++);
611         }
612
613         ff_slice_buffer_flush(&s->sb);
614         }
615
616     }
617
618     emms_c();
619
620     ff_snow_release_buffer(avctx);
621
622     if(!(s->avctx->debug&2048))
623         res = av_frame_ref(picture, s->current_picture);
624     else
625         res = av_frame_ref(picture, s->mconly_picture);
626     if (res >= 0 && s->avmv_index) {
627         AVFrameSideData *sd;
628
629         sd = av_frame_new_side_data(picture, AV_FRAME_DATA_MOTION_VECTORS, s->avmv_index * sizeof(AVMotionVector));
630         if (!sd)
631             return AVERROR(ENOMEM);
632         memcpy(sd->data, s->avmv, s->avmv_index * sizeof(AVMotionVector));
633     }
634
635     av_freep(&s->avmv);
636
637     if (res < 0)
638         return res;
639
640     *got_frame = 1;
641
642     bytes_read= c->bytestream - c->bytestream_start;
643     if(bytes_read ==0) av_log(s->avctx, AV_LOG_ERROR, "error at end of frame\n"); //FIXME
644
645     return bytes_read;
646 }
647
648 static av_cold int decode_end(AVCodecContext *avctx)
649 {
650     SnowContext *s = avctx->priv_data;
651
652     ff_slice_buffer_destroy(&s->sb);
653
654     ff_snow_common_end(s);
655
656     return 0;
657 }
658
659 AVCodec ff_snow_decoder = {
660     .name           = "snow",
661     .long_name      = NULL_IF_CONFIG_SMALL("Snow"),
662     .type           = AVMEDIA_TYPE_VIDEO,
663     .id             = AV_CODEC_ID_SNOW,
664     .priv_data_size = sizeof(SnowContext),
665     .init           = decode_init,
666     .close          = decode_end,
667     .decode         = decode_frame,
668     .capabilities   = AV_CODEC_CAP_DR1 /*| AV_CODEC_CAP_DRAW_HORIZ_BAND*/,
669     .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE |
670                       FF_CODEC_CAP_INIT_CLEANUP,
671 };