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1 /*
2  * Copyright (C) 2004 Michael Niedermayer <michaelni@gmx.at>
3  * Copyright (C) 2006 Robert Edele <yartrebo@earthlink.net>
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #ifndef AVCODEC_SNOW_H
23 #define AVCODEC_SNOW_H
24 
25 #include "libavutil/motion_vector.h"
26 
27 #include "hpeldsp.h"
28 #include "me_cmp.h"
29 #include "qpeldsp.h"
30 #include "snow_dwt.h"
31 
32 #include "rangecoder.h"
33 #include "mathops.h"
34 
35 #include "mpegvideo.h"
36 #include "h264qpel.h"
37 
38 #define SNOW_MAX_PLANES 4
39 
40 #define FF_ME_ITER 3
41 
42 #define MID_STATE 128
43 
44 #define MAX_PLANES 4
45 #define QSHIFT 5
46 #define QROOT (1<<QSHIFT)
47 #define LOSSLESS_QLOG -128
48 #define FRAC_BITS 4
49 #define MAX_REF_FRAMES 8
50 
51 #define LOG2_OBMC_MAX 8
52 #define OBMC_MAX (1<<(LOG2_OBMC_MAX))
53 typedef struct BlockNode{
54     int16_t mx;                 ///< Motion vector component X, see mv_scale
55     int16_t my;                 ///< Motion vector component Y, see mv_scale
56     uint8_t ref;                ///< Reference frame index
57     uint8_t color[3];           ///< Color for intra
58     uint8_t type;               ///< Bitfield of BLOCK_*
59 //#define TYPE_SPLIT    1
60 #define BLOCK_INTRA   1         ///< Intra block, inter otherwise
61 #define BLOCK_OPT     2         ///< Block needs no checks in this round of iterative motion estiation
62 //#define TYPE_NOCOLOR  4
63     uint8_t level; //FIXME merge into type?
64 }BlockNode;
65 
66 static const BlockNode null_block= { //FIXME add border maybe
67     .color= {128,128,128},
68     .mx= 0,
69     .my= 0,
70     .ref= 0,
71     .type= 0,
72     .level= 0,
73 };
74 
75 #define LOG2_MB_SIZE 4
76 #define MB_SIZE (1<<LOG2_MB_SIZE)
77 #define ENCODER_EXTRA_BITS 4
78 #define HTAPS_MAX 8
79 
80 typedef struct x_and_coeff{
81     int16_t x;
82     uint16_t coeff;
83 } x_and_coeff;
84 
85 typedef struct SubBand{
86     int level;
87     int stride;
88     int width;
89     int height;
90     int qlog;        ///< log(qscale)/log[2^(1/6)]
91     DWTELEM *buf;
92     IDWTELEM *ibuf;
93     int buf_x_offset;
94     int buf_y_offset;
95     int stride_line; ///< Stride measured in lines, not pixels.
96     x_and_coeff * x_coeff;
97     struct SubBand *parent;
98     uint8_t state[/*7*2*/ 7 + 512][32];
99 }SubBand;
100 
101 typedef struct Plane{
102     int width;
103     int height;
104     SubBand band[MAX_DECOMPOSITIONS][4];
105 
106     int htaps;
107     int8_t hcoeff[HTAPS_MAX/2];
108     int diag_mc;
109     int fast_mc;
110 
111     int last_htaps;
112     int8_t last_hcoeff[HTAPS_MAX/2];
113     int last_diag_mc;
114 }Plane;
115 
116 typedef struct SnowContext{
117     AVClass *class;
118     AVCodecContext *avctx;
119     RangeCoder c;
120     MECmpContext mecc;
121     HpelDSPContext hdsp;
122     QpelDSPContext qdsp;
123     VideoDSPContext vdsp;
124     H264QpelContext h264qpel;
125     MpegvideoEncDSPContext mpvencdsp;
126     SnowDWTContext dwt;
127     AVFrame *input_picture;              ///< new_picture with the internal linesizes
128     AVFrame *current_picture;
129     AVFrame *last_picture[MAX_REF_FRAMES];
130     uint8_t *halfpel_plane[MAX_REF_FRAMES][4][4];
131     AVFrame *mconly_picture;
132 //     uint8_t q_context[16];
133     uint8_t header_state[32];
134     uint8_t block_state[128 + 32*128];
135     int keyframe;
136     int always_reset;
137     int version;
138     int spatial_decomposition_type;
139     int last_spatial_decomposition_type;
140     int temporal_decomposition_type;
141     int spatial_decomposition_count;
142     int last_spatial_decomposition_count;
143     int temporal_decomposition_count;
144     int max_ref_frames;
145     int ref_frames;
146     int16_t (*ref_mvs[MAX_REF_FRAMES])[2];
147     uint32_t *ref_scores[MAX_REF_FRAMES];
148     DWTELEM *spatial_dwt_buffer;
149     DWTELEM *temp_dwt_buffer;
150     IDWTELEM *spatial_idwt_buffer;
151     IDWTELEM *temp_idwt_buffer;
152     int *run_buffer;
153     int colorspace_type;
154     int chroma_h_shift;
155     int chroma_v_shift;
156     int spatial_scalability;
157     int qlog;
158     int last_qlog;
159     int lambda;
160     int lambda2;
161     int pass1_rc;
162     int mv_scale;
163     int last_mv_scale;
164     int qbias;
165     int last_qbias;
166 #define QBIAS_SHIFT 3
167     int b_width;
168     int b_height;
169     int block_max_depth;
170     int last_block_max_depth;
171     int nb_planes;
172     Plane plane[MAX_PLANES];
173     BlockNode *block;
174 #define ME_CACHE_SIZE 1024
175     unsigned me_cache[ME_CACHE_SIZE];
176     unsigned me_cache_generation;
177     slice_buffer sb;
178     int memc_only;
179     int no_bitstream;
180     int intra_penalty;
181     int motion_est;
182     int iterative_dia_size;
183     int scenechange_threshold;
184 
185     MpegEncContext m; // needed for motion estimation, should not be used for anything else, the idea is to eventually make the motion estimation independent of MpegEncContext, so this will be removed then (FIXME/XXX)
186 
187     uint8_t *scratchbuf;
188     uint8_t *emu_edge_buffer;
189 
190     AVMotionVector *avmv;
191     unsigned avmv_size;
192     int avmv_index;
193     uint64_t encoding_error[SNOW_MAX_PLANES];
194 
195     int pred;
196 }SnowContext;
197 
198 /* Tables */
199 extern const uint8_t * const ff_obmc_tab[4];
200 extern const uint8_t ff_qexp[QROOT];
201 extern int ff_scale_mv_ref[MAX_REF_FRAMES][MAX_REF_FRAMES];
202 
203 /* C bits used by mmx/sse2/altivec */
204 
snow_interleave_line_header(int * i,int width,IDWTELEM * low,IDWTELEM * high)205 static av_always_inline void snow_interleave_line_header(int * i, int width, IDWTELEM * low, IDWTELEM * high){
206     (*i) = (width) - 2;
207 
208     if (width & 1){
209         low[(*i)+1] = low[((*i)+1)>>1];
210         (*i)--;
211     }
212 }
213 
snow_interleave_line_footer(int * i,IDWTELEM * low,IDWTELEM * high)214 static av_always_inline void snow_interleave_line_footer(int * i, IDWTELEM * low, IDWTELEM * high){
215     for (; (*i)>=0; (*i)-=2){
216         low[(*i)+1] = high[(*i)>>1];
217         low[*i] = low[(*i)>>1];
218     }
219 }
220 
snow_horizontal_compose_lift_lead_out(int i,IDWTELEM * dst,IDWTELEM * src,IDWTELEM * ref,int width,int w,int lift_high,int mul,int add,int shift)221 static av_always_inline void snow_horizontal_compose_lift_lead_out(int i, IDWTELEM * dst, IDWTELEM * src, IDWTELEM * ref, int width, int w, int lift_high, int mul, int add, int shift){
222     for(; i<w; i++){
223         dst[i] = src[i] - ((mul * (ref[i] + ref[i + 1]) + add) >> shift);
224     }
225 
226     if((width^lift_high)&1){
227         dst[w] = src[w] - ((mul * 2 * ref[w] + add) >> shift);
228     }
229 }
230 
snow_horizontal_compose_liftS_lead_out(int i,IDWTELEM * dst,IDWTELEM * src,IDWTELEM * ref,int width,int w)231 static av_always_inline void snow_horizontal_compose_liftS_lead_out(int i, IDWTELEM * dst, IDWTELEM * src, IDWTELEM * ref, int width, int w){
232         for(; i<w; i++){
233             dst[i] = src[i] + ((ref[i] + ref[(i+1)]+W_BO + 4 * src[i]) >> W_BS);
234         }
235 
236         if(width&1){
237             dst[w] = src[w] + ((2 * ref[w] + W_BO + 4 * src[w]) >> W_BS);
238         }
239 }
240 
241 /* common code */
242 
243 int ff_snow_common_init(AVCodecContext *avctx);
244 int ff_snow_common_init_after_header(AVCodecContext *avctx);
245 void ff_snow_common_end(SnowContext *s);
246 void ff_snow_release_buffer(AVCodecContext *avctx);
247 void ff_snow_reset_contexts(SnowContext *s);
248 int ff_snow_alloc_blocks(SnowContext *s);
249 int ff_snow_frame_start(SnowContext *s);
250 void ff_snow_pred_block(SnowContext *s, uint8_t *dst, uint8_t *tmp, ptrdiff_t stride,
251                      int sx, int sy, int b_w, int b_h, const BlockNode *block,
252                      int plane_index, int w, int h);
253 int ff_snow_get_buffer(SnowContext *s, AVFrame *frame);
254 /* common inline functions */
255 //XXX doublecheck all of them should stay inlined
256 
pred_mv(SnowContext * s,int * mx,int * my,int ref,const BlockNode * left,const BlockNode * top,const BlockNode * tr)257 static inline void pred_mv(SnowContext *s, int *mx, int *my, int ref,
258                            const BlockNode *left, const BlockNode *top, const BlockNode *tr){
259     if(s->ref_frames == 1){
260         *mx = mid_pred(left->mx, top->mx, tr->mx);
261         *my = mid_pred(left->my, top->my, tr->my);
262     }else{
263         const int *scale = ff_scale_mv_ref[ref];
264         *mx = mid_pred((left->mx * scale[left->ref] + 128) >>8,
265                        (top ->mx * scale[top ->ref] + 128) >>8,
266                        (tr  ->mx * scale[tr  ->ref] + 128) >>8);
267         *my = mid_pred((left->my * scale[left->ref] + 128) >>8,
268                        (top ->my * scale[top ->ref] + 128) >>8,
269                        (tr  ->my * scale[tr  ->ref] + 128) >>8);
270     }
271 }
272 
same_block(BlockNode * a,BlockNode * b)273 static av_always_inline int same_block(BlockNode *a, BlockNode *b){
274     if((a->type&BLOCK_INTRA) && (b->type&BLOCK_INTRA)){
275         return !((a->color[0] - b->color[0]) | (a->color[1] - b->color[1]) | (a->color[2] - b->color[2]));
276     }else{
277         return !((a->mx - b->mx) | (a->my - b->my) | (a->ref - b->ref) | ((a->type ^ b->type)&BLOCK_INTRA));
278     }
279 }
280 
281 //FIXME name cleanup (b_w, block_w, b_width stuff)
282 //XXX should we really inline it?
add_yblock(SnowContext * s,int sliced,slice_buffer * sb,IDWTELEM * dst,uint8_t * dst8,const uint8_t * obmc,int src_x,int src_y,int b_w,int b_h,int w,int h,int dst_stride,int src_stride,int obmc_stride,int b_x,int b_y,int add,int offset_dst,int plane_index)283 static av_always_inline void add_yblock(SnowContext *s, int sliced, slice_buffer *sb, IDWTELEM *dst, uint8_t *dst8, const uint8_t *obmc, int src_x, int src_y, int b_w, int b_h, int w, int h, int dst_stride, int src_stride, int obmc_stride, int b_x, int b_y, int add, int offset_dst, int plane_index){
284     const int b_width = s->b_width  << s->block_max_depth;
285     const int b_height= s->b_height << s->block_max_depth;
286     const int b_stride= b_width;
287     BlockNode *lt= &s->block[b_x + b_y*b_stride];
288     BlockNode *rt= lt+1;
289     BlockNode *lb= lt+b_stride;
290     BlockNode *rb= lb+1;
291     uint8_t *block[4];
292     // When src_stride is large enough, it is possible to interleave the blocks.
293     // Otherwise the blocks are written sequentially in the tmp buffer.
294     int tmp_step= src_stride >= 7*MB_SIZE ? MB_SIZE : MB_SIZE*src_stride;
295     uint8_t *tmp = s->scratchbuf;
296     uint8_t *ptmp;
297     int x,y;
298 
299     if(b_x<0){
300         lt= rt;
301         lb= rb;
302     }else if(b_x + 1 >= b_width){
303         rt= lt;
304         rb= lb;
305     }
306     if(b_y<0){
307         lt= lb;
308         rt= rb;
309     }else if(b_y + 1 >= b_height){
310         lb= lt;
311         rb= rt;
312     }
313 
314     if(src_x<0){ //FIXME merge with prev & always round internal width up to *16
315         obmc -= src_x;
316         b_w += src_x;
317         if(!sliced && !offset_dst)
318             dst -= src_x;
319         src_x=0;
320     }
321     if(src_x + b_w > w){
322         b_w = w - src_x;
323     }
324     if(src_y<0){
325         obmc -= src_y*obmc_stride;
326         b_h += src_y;
327         if(!sliced && !offset_dst)
328             dst -= src_y*dst_stride;
329         src_y=0;
330     }
331     if(src_y + b_h> h){
332         b_h = h - src_y;
333     }
334 
335     if(b_w<=0 || b_h<=0) return;
336 
337     if(!sliced && offset_dst)
338         dst += src_x + src_y*dst_stride;
339     dst8+= src_x + src_y*src_stride;
340 //    src += src_x + src_y*src_stride;
341 
342     ptmp= tmp + 3*tmp_step;
343     block[0]= ptmp;
344     ptmp+=tmp_step;
345     ff_snow_pred_block(s, block[0], tmp, src_stride, src_x, src_y, b_w, b_h, lt, plane_index, w, h);
346 
347     if(same_block(lt, rt)){
348         block[1]= block[0];
349     }else{
350         block[1]= ptmp;
351         ptmp+=tmp_step;
352         ff_snow_pred_block(s, block[1], tmp, src_stride, src_x, src_y, b_w, b_h, rt, plane_index, w, h);
353     }
354 
355     if(same_block(lt, lb)){
356         block[2]= block[0];
357     }else if(same_block(rt, lb)){
358         block[2]= block[1];
359     }else{
360         block[2]= ptmp;
361         ptmp+=tmp_step;
362         ff_snow_pred_block(s, block[2], tmp, src_stride, src_x, src_y, b_w, b_h, lb, plane_index, w, h);
363     }
364 
365     if(same_block(lt, rb) ){
366         block[3]= block[0];
367     }else if(same_block(rt, rb)){
368         block[3]= block[1];
369     }else if(same_block(lb, rb)){
370         block[3]= block[2];
371     }else{
372         block[3]= ptmp;
373         ff_snow_pred_block(s, block[3], tmp, src_stride, src_x, src_y, b_w, b_h, rb, plane_index, w, h);
374     }
375     if(sliced){
376         s->dwt.inner_add_yblock(obmc, obmc_stride, block, b_w, b_h, src_x,src_y, src_stride, sb, add, dst8);
377     }else{
378         for(y=0; y<b_h; y++){
379             //FIXME ugly misuse of obmc_stride
380             const uint8_t *obmc1= obmc + y*obmc_stride;
381             const uint8_t *obmc2= obmc1+ (obmc_stride>>1);
382             const uint8_t *obmc3= obmc1+ obmc_stride*(obmc_stride>>1);
383             const uint8_t *obmc4= obmc3+ (obmc_stride>>1);
384             for(x=0; x<b_w; x++){
385                 int v=   obmc1[x] * block[3][x + y*src_stride]
386                         +obmc2[x] * block[2][x + y*src_stride]
387                         +obmc3[x] * block[1][x + y*src_stride]
388                         +obmc4[x] * block[0][x + y*src_stride];
389 
390                 v <<= 8 - LOG2_OBMC_MAX;
391                 if(FRAC_BITS != 8){
392                     v >>= 8 - FRAC_BITS;
393                 }
394                 if(add){
395                     v += dst[x + y*dst_stride];
396                     v = (v + (1<<(FRAC_BITS-1))) >> FRAC_BITS;
397                     if(v&(~255)) v= ~(v>>31);
398                     dst8[x + y*src_stride] = v;
399                 }else{
400                     dst[x + y*dst_stride] -= v;
401                 }
402             }
403         }
404     }
405 }
406 
predict_slice(SnowContext * s,IDWTELEM * buf,int plane_index,int add,int mb_y)407 static av_always_inline void predict_slice(SnowContext *s, IDWTELEM *buf, int plane_index, int add, int mb_y){
408     Plane *p= &s->plane[plane_index];
409     const int mb_w= s->b_width  << s->block_max_depth;
410     const int mb_h= s->b_height << s->block_max_depth;
411     int x, y, mb_x;
412     int block_size = MB_SIZE >> s->block_max_depth;
413     int block_w    = plane_index ? block_size>>s->chroma_h_shift : block_size;
414     int block_h    = plane_index ? block_size>>s->chroma_v_shift : block_size;
415     const uint8_t *obmc  = plane_index ? ff_obmc_tab[s->block_max_depth+s->chroma_h_shift] : ff_obmc_tab[s->block_max_depth];
416     const int obmc_stride= plane_index ? (2*block_size)>>s->chroma_h_shift : 2*block_size;
417     int ref_stride= s->current_picture->linesize[plane_index];
418     uint8_t *dst8= s->current_picture->data[plane_index];
419     int w= p->width;
420     int h= p->height;
421     av_assert2(s->chroma_h_shift == s->chroma_v_shift); // obmc params assume squares
422     if(s->keyframe || (s->avctx->debug&512)){
423         if(mb_y==mb_h)
424             return;
425 
426         if(add){
427             for(y=block_h*mb_y; y<FFMIN(h,block_h*(mb_y+1)); y++){
428                 for(x=0; x<w; x++){
429                     int v= buf[x + y*w] + (128<<FRAC_BITS) + (1<<(FRAC_BITS-1));
430                     v >>= FRAC_BITS;
431                     if(v&(~255)) v= ~(v>>31);
432                     dst8[x + y*ref_stride]= v;
433                 }
434             }
435         }else{
436             for(y=block_h*mb_y; y<FFMIN(h,block_h*(mb_y+1)); y++){
437                 for(x=0; x<w; x++){
438                     buf[x + y*w]-= 128<<FRAC_BITS;
439                 }
440             }
441         }
442 
443         return;
444     }
445 
446     for(mb_x=0; mb_x<=mb_w; mb_x++){
447         add_yblock(s, 0, NULL, buf, dst8, obmc,
448                    block_w*mb_x - block_w/2,
449                    block_h*mb_y - block_h/2,
450                    block_w, block_h,
451                    w, h,
452                    w, ref_stride, obmc_stride,
453                    mb_x - 1, mb_y - 1,
454                    add, 1, plane_index);
455     }
456 }
457 
predict_plane(SnowContext * s,IDWTELEM * buf,int plane_index,int add)458 static av_always_inline void predict_plane(SnowContext *s, IDWTELEM *buf, int plane_index, int add){
459     const int mb_h= s->b_height << s->block_max_depth;
460     int mb_y;
461     for(mb_y=0; mb_y<=mb_h; mb_y++)
462         predict_slice(s, buf, plane_index, add, mb_y);
463 }
464 
set_blocks(SnowContext * s,int level,int x,int y,int l,int cb,int cr,int mx,int my,int ref,int type)465 static inline void set_blocks(SnowContext *s, int level, int x, int y, int l, int cb, int cr, int mx, int my, int ref, int type){
466     const int w= s->b_width << s->block_max_depth;
467     const int rem_depth= s->block_max_depth - level;
468     const int index= (x + y*w) << rem_depth;
469     const int block_w= 1<<rem_depth;
470     const int block_h= 1<<rem_depth; //FIXME "w!=h"
471     BlockNode block;
472     int i,j;
473 
474     block.color[0]= l;
475     block.color[1]= cb;
476     block.color[2]= cr;
477     block.mx= mx;
478     block.my= my;
479     block.ref= ref;
480     block.type= type;
481     block.level= level;
482 
483     for(j=0; j<block_h; j++){
484         for(i=0; i<block_w; i++){
485             s->block[index + i + j*w]= block;
486         }
487     }
488 }
489 
init_ref(MotionEstContext * c,uint8_t * src[3],uint8_t * ref[3],uint8_t * ref2[3],int x,int y,int ref_index)490 static inline void init_ref(MotionEstContext *c, uint8_t *src[3], uint8_t *ref[3], uint8_t *ref2[3], int x, int y, int ref_index){
491     SnowContext *s = c->avctx->priv_data;
492     const int offset[3]= {
493           y*c->  stride + x,
494         ((y*c->uvstride + x)>>s->chroma_h_shift),
495         ((y*c->uvstride + x)>>s->chroma_h_shift),
496     };
497     int i;
498     for(i=0; i<3; i++){
499         c->src[0][i]= src [i];
500         c->ref[0][i]= ref [i] + offset[i];
501     }
502     av_assert2(!ref_index);
503 }
504 
505 
506 /* bitstream functions */
507 
508 extern const int8_t ff_quant3bA[256];
509 
510 #define QEXPSHIFT (7-FRAC_BITS+8) //FIXME try to change this to 0
511 
put_symbol(RangeCoder * c,uint8_t * state,int v,int is_signed)512 static inline void put_symbol(RangeCoder *c, uint8_t *state, int v, int is_signed){
513     int i;
514 
515     if(v){
516         const int a= FFABS(v);
517         const int e= av_log2(a);
518         const int el= FFMIN(e, 10);
519         put_rac(c, state+0, 0);
520 
521         for(i=0; i<el; i++){
522             put_rac(c, state+1+i, 1);  //1..10
523         }
524         for(; i<e; i++){
525             put_rac(c, state+1+9, 1);  //1..10
526         }
527         put_rac(c, state+1+FFMIN(i,9), 0);
528 
529         for(i=e-1; i>=el; i--){
530             put_rac(c, state+22+9, (a>>i)&1); //22..31
531         }
532         for(; i>=0; i--){
533             put_rac(c, state+22+i, (a>>i)&1); //22..31
534         }
535 
536         if(is_signed)
537             put_rac(c, state+11 + el, v < 0); //11..21
538     }else{
539         put_rac(c, state+0, 1);
540     }
541 }
542 
get_symbol(RangeCoder * c,uint8_t * state,int is_signed)543 static inline int get_symbol(RangeCoder *c, uint8_t *state, int is_signed){
544     if(get_rac(c, state+0))
545         return 0;
546     else{
547         int i, e;
548         unsigned a;
549         e= 0;
550         while(get_rac(c, state+1 + FFMIN(e,9))){ //1..10
551             e++;
552             if (e > 31)
553                 return AVERROR_INVALIDDATA;
554         }
555 
556         a= 1;
557         for(i=e-1; i>=0; i--){
558             a += a + get_rac(c, state+22 + FFMIN(i,9)); //22..31
559         }
560 
561         e= -(is_signed && get_rac(c, state+11 + FFMIN(e,10))); //11..21
562         return (a^e)-e;
563     }
564 }
565 
put_symbol2(RangeCoder * c,uint8_t * state,int v,int log2)566 static inline void put_symbol2(RangeCoder *c, uint8_t *state, int v, int log2){
567     int i;
568     int r= log2>=0 ? 1<<log2 : 1;
569 
570     av_assert2(v>=0);
571     av_assert2(log2>=-4);
572 
573     while(v >= r){
574         put_rac(c, state+4+log2, 1);
575         v -= r;
576         log2++;
577         if(log2>0) r+=r;
578     }
579     put_rac(c, state+4+log2, 0);
580 
581     for(i=log2-1; i>=0; i--){
582         put_rac(c, state+31-i, (v>>i)&1);
583     }
584 }
585 
get_symbol2(RangeCoder * c,uint8_t * state,int log2)586 static inline int get_symbol2(RangeCoder *c, uint8_t *state, int log2){
587     int i;
588     int r= log2>=0 ? 1<<log2 : 1;
589     int v=0;
590 
591     av_assert2(log2>=-4);
592 
593     while(log2<28 && get_rac(c, state+4+log2)){
594         v+= r;
595         log2++;
596         if(log2>0) r+=r;
597     }
598 
599     for(i=log2-1; i>=0; i--){
600         v+= get_rac(c, state+31-i)<<i;
601     }
602 
603     return v;
604 }
605 
unpack_coeffs(SnowContext * s,SubBand * b,SubBand * parent,int orientation)606 static inline void unpack_coeffs(SnowContext *s, SubBand *b, SubBand * parent, int orientation){
607     const int w= b->width;
608     const int h= b->height;
609     int x,y;
610 
611     int run, runs;
612     x_and_coeff *xc= b->x_coeff;
613     x_and_coeff *prev_xc= NULL;
614     x_and_coeff *prev2_xc= xc;
615     x_and_coeff *parent_xc= parent ? parent->x_coeff : NULL;
616     x_and_coeff *prev_parent_xc= parent_xc;
617 
618     runs= get_symbol2(&s->c, b->state[30], 0);
619     if(runs-- > 0) run= get_symbol2(&s->c, b->state[1], 3);
620     else           run= INT_MAX;
621 
622     for(y=0; y<h; y++){
623         int v=0;
624         int lt=0, t=0, rt=0;
625 
626         if(y && prev_xc->x == 0){
627             rt= prev_xc->coeff;
628         }
629         for(x=0; x<w; x++){
630             int p=0;
631             const int l= v;
632 
633             lt= t; t= rt;
634 
635             if(y){
636                 if(prev_xc->x <= x)
637                     prev_xc++;
638                 if(prev_xc->x == x + 1)
639                     rt= prev_xc->coeff;
640                 else
641                     rt=0;
642             }
643             if(parent_xc){
644                 if(x>>1 > parent_xc->x){
645                     parent_xc++;
646                 }
647                 if(x>>1 == parent_xc->x){
648                     p= parent_xc->coeff;
649                 }
650             }
651             if(/*ll|*/l|lt|t|rt|p){
652                 int context= av_log2(/*FFABS(ll) + */3*(l>>1) + (lt>>1) + (t&~1) + (rt>>1) + (p>>1));
653 
654                 v=get_rac(&s->c, &b->state[0][context]);
655                 if(v){
656                     v= 2*(get_symbol2(&s->c, b->state[context + 2], context-4) + 1);
657                     v+=get_rac(&s->c, &b->state[0][16 + 1 + 3 + ff_quant3bA[l&0xFF] + 3*ff_quant3bA[t&0xFF]]);
658                     if ((uint16_t)v != v) {
659                         av_log(s->avctx, AV_LOG_ERROR, "Coefficient damaged\n");
660                         v = 1;
661                     }
662                     xc->x=x;
663                     (xc++)->coeff= v;
664                 }
665             }else{
666                 if(!run){
667                     if(runs-- > 0) run= get_symbol2(&s->c, b->state[1], 3);
668                     else           run= INT_MAX;
669                     v= 2*(get_symbol2(&s->c, b->state[0 + 2], 0-4) + 1);
670                     v+=get_rac(&s->c, &b->state[0][16 + 1 + 3]);
671                     if ((uint16_t)v != v) {
672                         av_log(s->avctx, AV_LOG_ERROR, "Coefficient damaged\n");
673                         v = 1;
674                     }
675 
676                     xc->x=x;
677                     (xc++)->coeff= v;
678                 }else{
679                     int max_run;
680                     run--;
681                     v=0;
682                     av_assert2(run >= 0);
683                     if(y) max_run= FFMIN(run, prev_xc->x - x - 2);
684                     else  max_run= FFMIN(run, w-x-1);
685                     if(parent_xc)
686                         max_run= FFMIN(max_run, 2*parent_xc->x - x - 1);
687                     av_assert2(max_run >= 0 && max_run <= run);
688 
689                     x+= max_run;
690                     run-= max_run;
691                 }
692             }
693         }
694         (xc++)->x= w+1; //end marker
695         prev_xc= prev2_xc;
696         prev2_xc= xc;
697 
698         if(parent_xc){
699             if(y&1){
700                 while(parent_xc->x != parent->width+1)
701                     parent_xc++;
702                 parent_xc++;
703                 prev_parent_xc= parent_xc;
704             }else{
705                 parent_xc= prev_parent_xc;
706             }
707         }
708     }
709 
710     (xc++)->x= w+1; //end marker
711 }
712 
713 #endif /* AVCODEC_SNOW_H */
714