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 "codec_internal.h"
26 #include "snow_dwt.h"
27 #include "snow.h"
28 
29 #include "rangecoder.h"
30 #include "mathops.h"
31 
predict_slice_buffered(SnowContext *s, slice_buffer * sb, IDWTELEM * old_buffer, int plane_index, int add, int mb_y)32 static av_always_inline void predict_slice_buffered(SnowContext *s, slice_buffer * sb, IDWTELEM * old_buffer, int plane_index, int add, int mb_y){
33     Plane *p= &s->plane[plane_index];
34     const int mb_w= s->b_width  << s->block_max_depth;
35     const int mb_h= s->b_height << s->block_max_depth;
36     int x, y, mb_x;
37     int block_size = MB_SIZE >> s->block_max_depth;
38     int block_w    = plane_index ? block_size>>s->chroma_h_shift : block_size;
39     int block_h    = plane_index ? block_size>>s->chroma_v_shift : block_size;
40     const uint8_t *obmc  = plane_index ? ff_obmc_tab[s->block_max_depth+s->chroma_h_shift] : ff_obmc_tab[s->block_max_depth];
41     int obmc_stride= plane_index ? (2*block_size)>>s->chroma_h_shift : 2*block_size;
42     int ref_stride= s->current_picture->linesize[plane_index];
43     uint8_t *dst8= s->current_picture->data[plane_index];
44     int w= p->width;
45     int h= p->height;
46 
47     if(s->keyframe || (s->avctx->debug&512)){
48         if(mb_y==mb_h)
49             return;
50 
51         if(add){
52             for(y=block_h*mb_y; y<FFMIN(h,block_h*(mb_y+1)); y++){
53 //                DWTELEM * line = slice_buffer_get_line(sb, y);
54                 IDWTELEM * line = sb->line[y];
55                 for(x=0; x<w; x++){
56 //                    int v= buf[x + y*w] + (128<<FRAC_BITS) + (1<<(FRAC_BITS-1));
57                     int v= line[x] + (128<<FRAC_BITS) + (1<<(FRAC_BITS-1));
58                     v >>= FRAC_BITS;
59                     if(v&(~255)) v= ~(v>>31);
60                     dst8[x + y*ref_stride]= v;
61                 }
62             }
63         }else{
64             for(y=block_h*mb_y; y<FFMIN(h,block_h*(mb_y+1)); y++){
65 //                DWTELEM * line = slice_buffer_get_line(sb, y);
66                 IDWTELEM * line = sb->line[y];
67                 for(x=0; x<w; x++){
68                     line[x] -= 128 << FRAC_BITS;
69 //                    buf[x + y*w]-= 128<<FRAC_BITS;
70                 }
71             }
72         }
73 
74         return;
75     }
76 
77     for(mb_x=0; mb_x<=mb_w; mb_x++){
78         add_yblock(s, 1, sb, old_buffer, dst8, obmc,
79                    block_w*mb_x - block_w/2,
80                    block_h*mb_y - block_h/2,
81                    block_w, block_h,
82                    w, h,
83                    w, ref_stride, obmc_stride,
84                    mb_x - 1, mb_y - 1,
85                    add, 0, plane_index);
86     }
87 
88     if(s->avmv && mb_y < mb_h && plane_index == 0)
89         for(mb_x=0; mb_x<mb_w; mb_x++){
90             AVMotionVector *avmv = s->avmv + s->avmv_index;
91             const int b_width = s->b_width  << s->block_max_depth;
92             const int b_stride= b_width;
93             BlockNode *bn= &s->block[mb_x + mb_y*b_stride];
94 
95             if (bn->type)
96                 continue;
97 
98             s->avmv_index++;
99 
100             avmv->w = block_w;
101             avmv->h = block_h;
102             avmv->dst_x = block_w*mb_x - block_w/2;
103             avmv->dst_y = block_h*mb_y - block_h/2;
104             avmv->motion_scale = 8;
105             avmv->motion_x = bn->mx * s->mv_scale;
106             avmv->motion_y = bn->my * s->mv_scale;
107             avmv->src_x = avmv->dst_x + avmv->motion_x / 8;
108             avmv->src_y = avmv->dst_y + avmv->motion_y / 8;
109             avmv->source= -1 - bn->ref;
110             avmv->flags = 0;
111         }
112 }
113 
decode_subband_slice_buffered(SnowContext *s, SubBand *b, slice_buffer * sb, int start_y, int h, int save_state[1])114 static inline void decode_subband_slice_buffered(SnowContext *s, SubBand *b, slice_buffer * sb, int start_y, int h, int save_state[1]){
115     const int w= b->width;
116     int y;
117     const int qlog= av_clip(s->qlog + (int64_t)b->qlog, 0, QROOT*16);
118     int qmul= ff_qexp[qlog&(QROOT-1)]<<(qlog>>QSHIFT);
119     int qadd= (s->qbias*qmul)>>QBIAS_SHIFT;
120     int new_index = 0;
121 
122     if(b->ibuf == s->spatial_idwt_buffer || s->qlog == LOSSLESS_QLOG){
123         qadd= 0;
124         qmul= 1<<QEXPSHIFT;
125     }
126 
127     /* If we are on the second or later slice, restore our index. */
128     if (start_y != 0)
129         new_index = save_state[0];
130 
131 
132     for(y=start_y; y<h; y++){
133         int x = 0;
134         int v;
135         IDWTELEM * line = slice_buffer_get_line(sb, y * b->stride_line + b->buf_y_offset) + b->buf_x_offset;
136         memset(line, 0, b->width*sizeof(IDWTELEM));
137         v = b->x_coeff[new_index].coeff;
138         x = b->x_coeff[new_index++].x;
139         while(x < w){
140             register int t= (int)( (v>>1)*(unsigned)qmul + qadd)>>QEXPSHIFT;
141             register int u= -(v&1);
142             line[x] = (t^u) - u;
143 
144             v = b->x_coeff[new_index].coeff;
145             x = b->x_coeff[new_index++].x;
146         }
147     }
148 
149     /* Save our variables for the next slice. */
150     save_state[0] = new_index;
151 
152     return;
153 }
154 
decode_q_branch(SnowContext *s, int level, int x, int y)155 static int decode_q_branch(SnowContext *s, int level, int x, int y){
156     const int w= s->b_width << s->block_max_depth;
157     const int rem_depth= s->block_max_depth - level;
158     const int index= (x + y*w) << rem_depth;
159     int trx= (x+1)<<rem_depth;
160     const BlockNode *left  = x ? &s->block[index-1] : &null_block;
161     const BlockNode *top   = y ? &s->block[index-w] : &null_block;
162     const BlockNode *tl    = y && x ? &s->block[index-w-1] : left;
163     const BlockNode *tr    = y && trx<w && ((x&1)==0 || level==0) ? &s->block[index-w+(1<<rem_depth)] : tl; //FIXME use lt
164     int s_context= 2*left->level + 2*top->level + tl->level + tr->level;
165     int res;
166 
167     if(s->keyframe){
168         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);
169         return 0;
170     }
171 
172     if(level==s->block_max_depth || get_rac(&s->c, &s->block_state[4 + s_context])){
173         int type, mx, my;
174         int l = left->color[0];
175         int cb= left->color[1];
176         int cr= left->color[2];
177         unsigned ref = 0;
178         int ref_context= av_log2(2*left->ref) + av_log2(2*top->ref);
179         int mx_context= av_log2(2*FFABS(left->mx - top->mx)) + 0*av_log2(2*FFABS(tr->mx - top->mx));
180         int my_context= av_log2(2*FFABS(left->my - top->my)) + 0*av_log2(2*FFABS(tr->my - top->my));
181 
182         type= get_rac(&s->c, &s->block_state[1 + left->type + top->type]) ? BLOCK_INTRA : 0;
183         if(type){
184             int ld, cbd, crd;
185             pred_mv(s, &mx, &my, 0, left, top, tr);
186             ld = get_symbol(&s->c, &s->block_state[32], 1);
187             if (ld < -255 || ld > 255) {
188                 return AVERROR_INVALIDDATA;
189             }
190             l += ld;
191             if (s->nb_planes > 2) {
192                 cbd = get_symbol(&s->c, &s->block_state[64], 1);
193                 crd = get_symbol(&s->c, &s->block_state[96], 1);
194                 if (cbd < -255 || cbd > 255 || crd < -255 || crd > 255) {
195                     return AVERROR_INVALIDDATA;
196                 }
197                 cb += cbd;
198                 cr += crd;
199             }
200         }else{
201             if(s->ref_frames > 1)
202                 ref= get_symbol(&s->c, &s->block_state[128 + 1024 + 32*ref_context], 0);
203             if (ref >= s->ref_frames) {
204                 av_log(s->avctx, AV_LOG_ERROR, "Invalid ref\n");
205                 return AVERROR_INVALIDDATA;
206             }
207             pred_mv(s, &mx, &my, ref, left, top, tr);
208             mx+= (unsigned)get_symbol(&s->c, &s->block_state[128 + 32*(mx_context + 16*!!ref)], 1);
209             my+= (unsigned)get_symbol(&s->c, &s->block_state[128 + 32*(my_context + 16*!!ref)], 1);
210         }
211         set_blocks(s, level, x, y, l, cb, cr, mx, my, ref, type);
212     }else{
213         if ((res = decode_q_branch(s, level+1, 2*x+0, 2*y+0)) < 0 ||
214             (res = decode_q_branch(s, level+1, 2*x+1, 2*y+0)) < 0 ||
215             (res = decode_q_branch(s, level+1, 2*x+0, 2*y+1)) < 0 ||
216             (res = decode_q_branch(s, level+1, 2*x+1, 2*y+1)) < 0)
217             return res;
218     }
219     return 0;
220 }
221 
dequantize_slice_buffered(SnowContext *s, slice_buffer * sb, SubBand *b, IDWTELEM *src, int stride, int start_y, int end_y)222 static void dequantize_slice_buffered(SnowContext *s, slice_buffer * sb, SubBand *b, IDWTELEM *src, int stride, int start_y, int end_y){
223     const int w= b->width;
224     const int qlog= av_clip(s->qlog + (int64_t)b->qlog, 0, QROOT*16);
225     const int qmul= ff_qexp[qlog&(QROOT-1)]<<(qlog>>QSHIFT);
226     const int qadd= (s->qbias*qmul)>>QBIAS_SHIFT;
227     int x,y;
228 
229     if(s->qlog == LOSSLESS_QLOG) return;
230 
231     for(y=start_y; y<end_y; y++){
232 //        DWTELEM * line = slice_buffer_get_line_from_address(sb, src + (y * stride));
233         IDWTELEM * line = slice_buffer_get_line(sb, (y * b->stride_line) + b->buf_y_offset) + b->buf_x_offset;
234         for(x=0; x<w; x++){
235             int i= line[x];
236             if(i<0){
237                 line[x]= -((-i*(unsigned)qmul + qadd)>>(QEXPSHIFT)); //FIXME try different bias
238             }else if(i>0){
239                 line[x]=  (( i*(unsigned)qmul + qadd)>>(QEXPSHIFT));
240             }
241         }
242     }
243 }
244 
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)245 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){
246     const int w= b->width;
247     int x,y;
248 
249     IDWTELEM * line=0; // silence silly "could be used without having been initialized" warning
250     IDWTELEM * prev;
251 
252     if (start_y != 0)
253         line = slice_buffer_get_line(sb, ((start_y - 1) * b->stride_line) + b->buf_y_offset) + b->buf_x_offset;
254 
255     for(y=start_y; y<end_y; y++){
256         prev = line;
257 //        line = slice_buffer_get_line_from_address(sb, src + (y * stride));
258         line = slice_buffer_get_line(sb, (y * b->stride_line) + b->buf_y_offset) + b->buf_x_offset;
259         for(x=0; x<w; x++){
260             if(x){
261                 if(use_median){
262                     if(y && x+1<w) line[x] += mid_pred(line[x - 1], prev[x], prev[x + 1]);
263                     else  line[x] += line[x - 1];
264                 }else{
265                     if(y) line[x] += mid_pred(line[x - 1], prev[x], line[x - 1] + prev[x] - prev[x - 1]);
266                     else  line[x] += line[x - 1];
267                 }
268             }else{
269                 if(y) line[x] += prev[x];
270             }
271         }
272     }
273 }
274 
decode_qlogs(SnowContext *s)275 static void decode_qlogs(SnowContext *s){
276     int plane_index, level, orientation;
277 
278     for(plane_index=0; plane_index < s->nb_planes; plane_index++){
279         for(level=0; level<s->spatial_decomposition_count; level++){
280             for(orientation=level ? 1:0; orientation<4; orientation++){
281                 int q;
282                 if     (plane_index==2) q= s->plane[1].band[level][orientation].qlog;
283                 else if(orientation==2) q= s->plane[plane_index].band[level][1].qlog;
284                 else                    q= get_symbol(&s->c, s->header_state, 1);
285                 s->plane[plane_index].band[level][orientation].qlog= q;
286             }
287         }
288     }
289 }
290 
291 #define GET_S(dst, check) \
292     tmp= get_symbol(&s->c, s->header_state, 0);\
293     if(!(check)){\
294         av_log(s->avctx, AV_LOG_ERROR, "Error " #dst " is %d\n", tmp);\
295         return AVERROR_INVALIDDATA;\
296     }\
297     dst= tmp;
298 
decode_header(SnowContext *s)299 static int decode_header(SnowContext *s){
300     int plane_index, tmp;
301     uint8_t kstate[32];
302 
303     memset(kstate, MID_STATE, sizeof(kstate));
304 
305     s->keyframe= get_rac(&s->c, kstate);
306     if(s->keyframe || s->always_reset){
307         ff_snow_reset_contexts(s);
308         s->spatial_decomposition_type=
309         s->qlog=
310         s->qbias=
311         s->mv_scale=
312         s->block_max_depth= 0;
313     }
314     if(s->keyframe){
315         GET_S(s->version, tmp <= 0U)
316         s->always_reset= get_rac(&s->c, s->header_state);
317         s->temporal_decomposition_type= get_symbol(&s->c, s->header_state, 0);
318         s->temporal_decomposition_count= get_symbol(&s->c, s->header_state, 0);
319         GET_S(s->spatial_decomposition_count, 0 < tmp && tmp <= MAX_DECOMPOSITIONS)
320         s->colorspace_type= get_symbol(&s->c, s->header_state, 0);
321         if (s->colorspace_type == 1) {
322             s->avctx->pix_fmt= AV_PIX_FMT_GRAY8;
323             s->nb_planes = 1;
324         } else if(s->colorspace_type == 0) {
325             s->chroma_h_shift= get_symbol(&s->c, s->header_state, 0);
326             s->chroma_v_shift= get_symbol(&s->c, s->header_state, 0);
327 
328             if(s->chroma_h_shift == 1 && s->chroma_v_shift==1){
329                 s->avctx->pix_fmt= AV_PIX_FMT_YUV420P;
330             }else if(s->chroma_h_shift == 0 && s->chroma_v_shift==0){
331                 s->avctx->pix_fmt= AV_PIX_FMT_YUV444P;
332             }else if(s->chroma_h_shift == 2 && s->chroma_v_shift==2){
333                 s->avctx->pix_fmt= AV_PIX_FMT_YUV410P;
334             } else {
335                 av_log(s, AV_LOG_ERROR, "unsupported color subsample mode %d %d\n", s->chroma_h_shift, s->chroma_v_shift);
336                 s->chroma_h_shift = s->chroma_v_shift = 1;
337                 s->avctx->pix_fmt= AV_PIX_FMT_YUV420P;
338                 return AVERROR_INVALIDDATA;
339             }
340             s->nb_planes = 3;
341         } else {
342             av_log(s, AV_LOG_ERROR, "unsupported color space\n");
343             s->chroma_h_shift = s->chroma_v_shift = 1;
344             s->avctx->pix_fmt= AV_PIX_FMT_YUV420P;
345             return AVERROR_INVALIDDATA;
346         }
347 
348 
349         s->spatial_scalability= get_rac(&s->c, s->header_state);
350 //        s->rate_scalability= get_rac(&s->c, s->header_state);
351         GET_S(s->max_ref_frames, tmp < (unsigned)MAX_REF_FRAMES)
352         s->max_ref_frames++;
353 
354         decode_qlogs(s);
355     }
356 
357     if(!s->keyframe){
358         if(get_rac(&s->c, s->header_state)){
359             for(plane_index=0; plane_index<FFMIN(s->nb_planes, 2); plane_index++){
360                 int htaps, i, sum=0;
361                 Plane *p= &s->plane[plane_index];
362                 p->diag_mc= get_rac(&s->c, s->header_state);
363                 htaps= get_symbol(&s->c, s->header_state, 0);
364                 if((unsigned)htaps >= HTAPS_MAX/2 - 1)
365                     return AVERROR_INVALIDDATA;
366                 htaps = htaps*2 + 2;
367                 p->htaps= htaps;
368                 for(i= htaps/2; i; i--){
369                     unsigned hcoeff = get_symbol(&s->c, s->header_state, 0);
370                     if (hcoeff > 127)
371                         return AVERROR_INVALIDDATA;
372                     p->hcoeff[i]= hcoeff * (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 
decode_blocks(SnowContext *s)422 static int decode_blocks(SnowContext *s){
423     int x, y;
424     int w= s->b_width;
425     int h= s->b_height;
426     int res;
427 
428     for(y=0; y<h; y++){
429         for(x=0; x<w; x++){
430             if (s->c.bytestream >= s->c.bytestream_end)
431                 return AVERROR_INVALIDDATA;
432             if ((res = decode_q_branch(s, 0, x, y)) < 0)
433                 return res;
434         }
435     }
436     return 0;
437 }
438 
decode_frame(AVCodecContext *avctx, AVFrame *picture, int *got_frame, AVPacket *avpkt)439 static int decode_frame(AVCodecContext *avctx, AVFrame *picture,
440                         int *got_frame, AVPacket *avpkt)
441 {
442     const uint8_t *buf = avpkt->data;
443     int buf_size = avpkt->size;
444     SnowContext *s = avctx->priv_data;
445     RangeCoder * const c= &s->c;
446     int bytes_read;
447     int level, orientation, plane_index;
448     int res;
449 
450     ff_init_range_decoder(c, buf, buf_size);
451     ff_build_rac_states(c, 0.05*(1LL<<32), 256-8);
452 
453     s->current_picture->pict_type= AV_PICTURE_TYPE_I; //FIXME I vs. P
454     if ((res = decode_header(s)) < 0)
455         return res;
456     if ((res=ff_snow_common_init_after_header(avctx)) < 0)
457         return res;
458 
459     // realloc slice buffer for the case that spatial_decomposition_count changed
460     ff_slice_buffer_destroy(&s->sb);
461     if ((res = ff_slice_buffer_init(&s->sb, s->plane[0].height,
462                                     (MB_SIZE >> s->block_max_depth) +
463                                     s->spatial_decomposition_count * 11 + 1,
464                                     s->plane[0].width,
465                                     s->spatial_idwt_buffer)) < 0)
466         return res;
467 
468     for(plane_index=0; plane_index < s->nb_planes; plane_index++){
469         Plane *p= &s->plane[plane_index];
470         p->fast_mc= p->diag_mc && p->htaps==6 && p->hcoeff[0]==40
471                                               && p->hcoeff[1]==-10
472                                               && p->hcoeff[2]==2;
473     }
474 
475     ff_snow_alloc_blocks(s);
476 
477     if((res = ff_snow_frame_start(s)) < 0)
478         return res;
479 
480     s->current_picture->pict_type = s->keyframe ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
481 
482     //keyframe flag duplication mess FIXME
483     if(avctx->debug&FF_DEBUG_PICT_INFO)
484         av_log(avctx, AV_LOG_ERROR,
485                "keyframe:%d qlog:%d qbias: %d mvscale: %d "
486                "decomposition_type:%d decomposition_count:%d\n",
487                s->keyframe, s->qlog, s->qbias, s->mv_scale,
488                s->spatial_decomposition_type,
489                s->spatial_decomposition_count
490               );
491 
492     if (s->avctx->export_side_data & AV_CODEC_EXPORT_DATA_MVS) {
493         size_t size;
494         res = av_size_mult(s->b_width * s->b_height, sizeof(AVMotionVector) << (s->block_max_depth*2), &size);
495         if (res)
496             return res;
497         av_fast_malloc(&s->avmv, &s->avmv_size, size);
498         if (!s->avmv)
499             return AVERROR(ENOMEM);
500     } else {
501         s->avmv_size = 0;
502         av_freep(&s->avmv);
503     }
504     s->avmv_index = 0;
505 
506     if ((res = decode_blocks(s)) < 0)
507         return res;
508 
509     for(plane_index=0; plane_index < s->nb_planes; plane_index++){
510         Plane *p= &s->plane[plane_index];
511         int w= p->width;
512         int h= p->height;
513         int x, y;
514         int decode_state[MAX_DECOMPOSITIONS][4][1]; /* Stored state info for unpack_coeffs. 1 variable per instance. */
515 
516         if(s->avctx->debug&2048){
517             memset(s->spatial_dwt_buffer, 0, sizeof(DWTELEM)*w*h);
518             predict_plane(s, s->spatial_idwt_buffer, plane_index, 1);
519 
520             for(y=0; y<h; y++){
521                 for(x=0; x<w; x++){
522                     int v= s->current_picture->data[plane_index][y*s->current_picture->linesize[plane_index] + x];
523                     s->mconly_picture->data[plane_index][y*s->mconly_picture->linesize[plane_index] + x]= v;
524                 }
525             }
526         }
527 
528         for(level=0; level<s->spatial_decomposition_count; level++){
529             for(orientation=level ? 1 : 0; orientation<4; orientation++){
530                 SubBand *b= &p->band[level][orientation];
531                 unpack_coeffs(s, b, b->parent, orientation);
532             }
533         }
534 
535         {
536         const int mb_h= s->b_height << s->block_max_depth;
537         const int block_size = MB_SIZE >> s->block_max_depth;
538         const int block_h    = plane_index ? block_size>>s->chroma_v_shift : block_size;
539         int mb_y;
540         DWTCompose cs[MAX_DECOMPOSITIONS];
541         int yd=0, yq=0;
542         int y;
543         int end_y;
544 
545         ff_spatial_idwt_buffered_init(cs, &s->sb, w, h, 1, s->spatial_decomposition_type, s->spatial_decomposition_count);
546         for(mb_y=0; mb_y<=mb_h; mb_y++){
547 
548             int slice_starty = block_h*mb_y;
549             int slice_h = block_h*(mb_y+1);
550 
551             if (!(s->keyframe || s->avctx->debug&512)){
552                 slice_starty = FFMAX(0, slice_starty - (block_h >> 1));
553                 slice_h -= (block_h >> 1);
554             }
555 
556             for(level=0; level<s->spatial_decomposition_count; level++){
557                 for(orientation=level ? 1 : 0; orientation<4; orientation++){
558                     SubBand *b= &p->band[level][orientation];
559                     int start_y;
560                     int end_y;
561                     int our_mb_start = mb_y;
562                     int our_mb_end = (mb_y + 1);
563                     const int extra= 3;
564                     start_y = (mb_y ? ((block_h * our_mb_start) >> (s->spatial_decomposition_count - level)) + s->spatial_decomposition_count - level + extra: 0);
565                     end_y = (((block_h * our_mb_end) >> (s->spatial_decomposition_count - level)) + s->spatial_decomposition_count - level + extra);
566                     if (!(s->keyframe || s->avctx->debug&512)){
567                         start_y = FFMAX(0, start_y - (block_h >> (1+s->spatial_decomposition_count - level)));
568                         end_y = FFMAX(0, end_y - (block_h >> (1+s->spatial_decomposition_count - level)));
569                     }
570                     start_y = FFMIN(b->height, start_y);
571                     end_y = FFMIN(b->height, end_y);
572 
573                     if (start_y != end_y){
574                         if (orientation == 0){
575                             SubBand * correlate_band = &p->band[0][0];
576                             int correlate_end_y = FFMIN(b->height, end_y + 1);
577                             int correlate_start_y = FFMIN(b->height, (start_y ? start_y + 1 : 0));
578                             decode_subband_slice_buffered(s, correlate_band, &s->sb, correlate_start_y, correlate_end_y, decode_state[0][0]);
579                             correlate_slice_buffered(s, &s->sb, correlate_band, correlate_band->ibuf, correlate_band->stride, 1, 0, correlate_start_y, correlate_end_y);
580                             dequantize_slice_buffered(s, &s->sb, correlate_band, correlate_band->ibuf, correlate_band->stride, start_y, end_y);
581                         }
582                         else
583                             decode_subband_slice_buffered(s, b, &s->sb, start_y, end_y, decode_state[level][orientation]);
584                     }
585                 }
586             }
587 
588             for(; yd<slice_h; yd+=4){
589                 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);
590             }
591 
592             if(s->qlog == LOSSLESS_QLOG){
593                 for(; yq<slice_h && yq<h; yq++){
594                     IDWTELEM * line = slice_buffer_get_line(&s->sb, yq);
595                     for(x=0; x<w; x++){
596                         line[x] *= 1<<FRAC_BITS;
597                     }
598                 }
599             }
600 
601             predict_slice_buffered(s, &s->sb, s->spatial_idwt_buffer, plane_index, 1, mb_y);
602 
603             y = FFMIN(p->height, slice_starty);
604             end_y = FFMIN(p->height, slice_h);
605             while(y < end_y)
606                 ff_slice_buffer_release(&s->sb, y++);
607         }
608 
609         ff_slice_buffer_flush(&s->sb);
610         }
611 
612     }
613 
614     emms_c();
615 
616     ff_snow_release_buffer(avctx);
617 
618     if(!(s->avctx->debug&2048))
619         res = av_frame_ref(picture, s->current_picture);
620     else
621         res = av_frame_ref(picture, s->mconly_picture);
622     if (res >= 0 && s->avmv_index) {
623         AVFrameSideData *sd;
624 
625         sd = av_frame_new_side_data(picture, AV_FRAME_DATA_MOTION_VECTORS, s->avmv_index * sizeof(AVMotionVector));
626         if (!sd)
627             return AVERROR(ENOMEM);
628         memcpy(sd->data, s->avmv, s->avmv_index * sizeof(AVMotionVector));
629     }
630 
631     if (res < 0)
632         return res;
633 
634     *got_frame = 1;
635 
636     bytes_read= c->bytestream - c->bytestream_start;
637     if(bytes_read ==0) av_log(s->avctx, AV_LOG_ERROR, "error at end of frame\n"); //FIXME
638 
639     return bytes_read;
640 }
641 
decode_end(AVCodecContext *avctx)642 static av_cold int decode_end(AVCodecContext *avctx)
643 {
644     SnowContext *s = avctx->priv_data;
645 
646     ff_slice_buffer_destroy(&s->sb);
647 
648     ff_snow_common_end(s);
649 
650     s->avmv_size = 0;
651     av_freep(&s->avmv);
652 
653     return 0;
654 }
655 
656 const FFCodec ff_snow_decoder = {
657     .p.name         = "snow",
658     .p.long_name    = NULL_IF_CONFIG_SMALL("Snow"),
659     .p.type         = AVMEDIA_TYPE_VIDEO,
660     .p.id           = AV_CODEC_ID_SNOW,
661     .priv_data_size = sizeof(SnowContext),
662     .init           = ff_snow_common_init,
663     .close          = decode_end,
664     FF_CODEC_DECODE_CB(decode_frame),
665     .p.capabilities = AV_CODEC_CAP_DR1 /*| AV_CODEC_CAP_DRAW_HORIZ_BAND*/,
666     .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE |
667                       FF_CODEC_CAP_INIT_CLEANUP,
668 };
669