FFmpeg: libavcodec/snow.h Source File

00001 /*
00002  * Copyright (C) 2004 Michael Niedermayer <michaelni@gmx.at>
00003  * Copyright (C) 2006 Robert Edele <yartrebo@earthlink.net>
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 #ifndef AVCODEC_SNOW_H
00023 #define AVCODEC_SNOW_H
00024 
00025 #include "dsputil.h"
00026 #include "dwt.h"
00027 
00028 #include "rangecoder.h"
00029 #include "mathops.h"
00030 #include "mpegvideo.h"
00031 
00032 #define MID_STATE 128
00033 
00034 #define MAX_PLANES 4
00035 #define QSHIFT 5
00036 #define QROOT (1<<QSHIFT)
00037 #define LOSSLESS_QLOG -128
00038 #define FRAC_BITS 4
00039 #define MAX_REF_FRAMES 8
00040 
00041 #define LOG2_OBMC_MAX 8
00042 #define OBMC_MAX (1<<(LOG2_OBMC_MAX))
00043 typedef struct BlockNode{
00044     int16_t mx;
00045     int16_t my;
00046     uint8_t ref;
00047     uint8_t color[3];
00048     uint8_t type;
00049 //#define TYPE_SPLIT    1
00050 #define BLOCK_INTRA   1
00051 #define BLOCK_OPT     2
00052 //#define TYPE_NOCOLOR  4
00053     uint8_t level; //FIXME merge into type?
00054 }BlockNode;
00055 
00056 static const BlockNode null_block= { //FIXME add border maybe
00057     .color= {128,128,128},
00058     .mx= 0,
00059     .my= 0,
00060     .ref= 0,
00061     .type= 0,
00062     .level= 0,
00063 };
00064 
00065 #define LOG2_MB_SIZE 4
00066 #define MB_SIZE (1<<LOG2_MB_SIZE)
00067 #define ENCODER_EXTRA_BITS 4
00068 #define HTAPS_MAX 8
00069 
00070 typedef struct x_and_coeff{
00071     int16_t x;
00072     uint16_t coeff;
00073 } x_and_coeff;
00074 
00075 typedef struct SubBand{
00076     int level;
00077     int stride;
00078     int width;
00079     int height;
00080     int qlog;        
00081     DWTELEM *buf;
00082     IDWTELEM *ibuf;
00083     int buf_x_offset;
00084     int buf_y_offset;
00085     int stride_line; 
00086     x_and_coeff * x_coeff;
00087     struct SubBand *parent;
00088     uint8_t state[/*7*2*/ 7 + 512][32];
00089 }SubBand;
00090 
00091 typedef struct Plane{
00092     int width;
00093     int height;
00094     SubBand band[MAX_DECOMPOSITIONS][4];
00095 
00096     int htaps;
00097     int8_t hcoeff[HTAPS_MAX/2];
00098     int diag_mc;
00099     int fast_mc;
00100 
00101     int last_htaps;
00102     int8_t last_hcoeff[HTAPS_MAX/2];
00103     int last_diag_mc;
00104 }Plane;
00105 
00106 typedef struct SnowContext{
00107     AVClass *class;
00108     AVCodecContext *avctx;
00109     RangeCoder c;
00110     DSPContext dsp;
00111     DWTContext dwt;
00112     AVFrame new_picture;
00113     AVFrame input_picture;              
00114     AVFrame current_picture;
00115     AVFrame last_picture[MAX_REF_FRAMES];
00116     uint8_t *halfpel_plane[MAX_REF_FRAMES][4][4];
00117     AVFrame mconly_picture;
00118 //     uint8_t q_context[16];
00119     uint8_t header_state[32];
00120     uint8_t block_state[128 + 32*128];
00121     int keyframe;
00122     int always_reset;
00123     int version;
00124     int spatial_decomposition_type;
00125     int last_spatial_decomposition_type;
00126     int temporal_decomposition_type;
00127     int spatial_decomposition_count;
00128     int last_spatial_decomposition_count;
00129     int temporal_decomposition_count;
00130     int max_ref_frames;
00131     int ref_frames;
00132     int16_t (*ref_mvs[MAX_REF_FRAMES])[2];
00133     uint32_t *ref_scores[MAX_REF_FRAMES];
00134     DWTELEM *spatial_dwt_buffer;
00135     DWTELEM *temp_dwt_buffer;
00136     IDWTELEM *spatial_idwt_buffer;
00137     IDWTELEM *temp_idwt_buffer;
00138     int *run_buffer;
00139     int colorspace_type;
00140     int chroma_h_shift;
00141     int chroma_v_shift;
00142     int spatial_scalability;
00143     int qlog;
00144     int last_qlog;
00145     int lambda;
00146     int lambda2;
00147     int pass1_rc;
00148     int mv_scale;
00149     int last_mv_scale;
00150     int qbias;
00151     int last_qbias;
00152 #define QBIAS_SHIFT 3
00153     int b_width;
00154     int b_height;
00155     int block_max_depth;
00156     int last_block_max_depth;
00157     Plane plane[MAX_PLANES];
00158     BlockNode *block;
00159 #define ME_CACHE_SIZE 1024
00160     unsigned me_cache[ME_CACHE_SIZE];
00161     unsigned me_cache_generation;
00162     slice_buffer sb;
00163     int memc_only;
00164     int no_bitstream;
00165 
00166     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)
00167 
00168     uint8_t *scratchbuf;
00169     uint8_t *emu_edge_buffer;
00170 }SnowContext;
00171 
00172 /* Tables */
00173 extern const uint8_t * const ff_obmc_tab[4];
00174 extern uint8_t ff_qexp[QROOT];
00175 extern int ff_scale_mv_ref[MAX_REF_FRAMES][MAX_REF_FRAMES];
00176 
00177 /* C bits used by mmx/sse2/altivec */
00178 
00179 static av_always_inline void snow_interleave_line_header(int * i, int width, IDWTELEM * low, IDWTELEM * high){
00180     (*i) = (width) - 2;
00181 
00182     if (width & 1){
00183         low[(*i)+1] = low[((*i)+1)>>1];
00184         (*i)--;
00185     }
00186 }
00187 
00188 static av_always_inline void snow_interleave_line_footer(int * i, IDWTELEM * low, IDWTELEM * high){
00189     for (; (*i)>=0; (*i)-=2){
00190         low[(*i)+1] = high[(*i)>>1];
00191         low[*i] = low[(*i)>>1];
00192     }
00193 }
00194 
00195 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){
00196     for(; i<w; i++){
00197         dst[i] = src[i] - ((mul * (ref[i] + ref[i + 1]) + add) >> shift);
00198     }
00199 
00200     if((width^lift_high)&1){
00201         dst[w] = src[w] - ((mul * 2 * ref[w] + add) >> shift);
00202     }
00203 }
00204 
00205 static av_always_inline void snow_horizontal_compose_liftS_lead_out(int i, IDWTELEM * dst, IDWTELEM * src, IDWTELEM * ref, int width, int w){
00206         for(; i<w; i++){
00207             dst[i] = src[i] + ((ref[i] + ref[(i+1)]+W_BO + 4 * src[i]) >> W_BS);
00208         }
00209 
00210         if(width&1){
00211             dst[w] = src[w] + ((2 * ref[w] + W_BO + 4 * src[w]) >> W_BS);
00212         }
00213 }
00214 
00215 /* common code */
00216 
00217 int ff_snow_common_init(AVCodecContext *avctx);
00218 int ff_snow_common_init_after_header(AVCodecContext *avctx);
00219 void ff_snow_common_end(SnowContext *s);
00220 void ff_snow_release_buffer(AVCodecContext *avctx);
00221 void ff_snow_reset_contexts(SnowContext *s);
00222 int ff_snow_alloc_blocks(SnowContext *s);
00223 int ff_snow_frame_start(SnowContext *s);
00224 void ff_snow_pred_block(SnowContext *s, uint8_t *dst, uint8_t *tmp, int stride,
00225                      int sx, int sy, int b_w, int b_h, BlockNode *block,
00226                      int plane_index, int w, int h);
00227 /* common inline functions */
00228 //XXX doublecheck all of them should stay inlined
00229 
00230 static inline void snow_set_blocks(SnowContext *s, int level, int x, int y, int l, int cb, int cr, int mx, int my, int ref, int type){
00231     const int w= s->b_width << s->block_max_depth;
00232     const int rem_depth= s->block_max_depth - level;
00233     const int index= (x + y*w) << rem_depth;
00234     const int block_w= 1<<rem_depth;
00235     BlockNode block;
00236     int i,j;
00237 
00238     block.color[0]= l;
00239     block.color[1]= cb;
00240     block.color[2]= cr;
00241     block.mx= mx;
00242     block.my= my;
00243     block.ref= ref;
00244     block.type= type;
00245     block.level= level;
00246 
00247     for(j=0; j<block_w; j++){
00248         for(i=0; i<block_w; i++){
00249             s->block[index + i + j*w]= block;
00250         }
00251     }
00252 }
00253 
00254 static inline void pred_mv(SnowContext *s, int *mx, int *my, int ref,
00255                            const BlockNode *left, const BlockNode *top, const BlockNode *tr){
00256     if(s->ref_frames == 1){
00257         *mx = mid_pred(left->mx, top->mx, tr->mx);
00258         *my = mid_pred(left->my, top->my, tr->my);
00259     }else{
00260         const int *scale = ff_scale_mv_ref[ref];
00261         *mx = mid_pred((left->mx * scale[left->ref] + 128) >>8,
00262                        (top ->mx * scale[top ->ref] + 128) >>8,
00263                        (tr  ->mx * scale[tr  ->ref] + 128) >>8);
00264         *my = mid_pred((left->my * scale[left->ref] + 128) >>8,
00265                        (top ->my * scale[top ->ref] + 128) >>8,
00266                        (tr  ->my * scale[tr  ->ref] + 128) >>8);
00267     }
00268 }
00269 
00270 static av_always_inline int same_block(BlockNode *a, BlockNode *b){
00271     if((a->type&BLOCK_INTRA) && (b->type&BLOCK_INTRA)){
00272         return !((a->color[0] - b->color[0]) | (a->color[1] - b->color[1]) | (a->color[2] - b->color[2]));
00273     }else{
00274         return !((a->mx - b->mx) | (a->my - b->my) | (a->ref - b->ref) | ((a->type ^ b->type)&BLOCK_INTRA));
00275     }
00276 }
00277 
00278 //FIXME name cleanup (b_w, block_w, b_width stuff)
00279 //XXX should we really inline it?
00280 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){
00281     const int b_width = s->b_width  << s->block_max_depth;
00282     const int b_height= s->b_height << s->block_max_depth;
00283     const int b_stride= b_width;
00284     BlockNode *lt= &s->block[b_x + b_y*b_stride];
00285     BlockNode *rt= lt+1;
00286     BlockNode *lb= lt+b_stride;
00287     BlockNode *rb= lb+1;
00288     uint8_t *block[4];
00289     int tmp_step= src_stride >= 7*MB_SIZE ? MB_SIZE : MB_SIZE*src_stride;
00290     uint8_t *tmp = s->scratchbuf;
00291     uint8_t *ptmp;
00292     int x,y;
00293 
00294     if(b_x<0){
00295         lt= rt;
00296         lb= rb;
00297     }else if(b_x + 1 >= b_width){
00298         rt= lt;
00299         rb= lb;
00300     }
00301     if(b_y<0){
00302         lt= lb;
00303         rt= rb;
00304     }else if(b_y + 1 >= b_height){
00305         lb= lt;
00306         rb= rt;
00307     }
00308 
00309     if(src_x<0){ //FIXME merge with prev & always round internal width up to *16
00310         obmc -= src_x;
00311         b_w += src_x;
00312         if(!sliced && !offset_dst)
00313             dst -= src_x;
00314         src_x=0;
00315     }else if(src_x + b_w > w){
00316         b_w = w - src_x;
00317     }
00318     if(src_y<0){
00319         obmc -= src_y*obmc_stride;
00320         b_h += src_y;
00321         if(!sliced && !offset_dst)
00322             dst -= src_y*dst_stride;
00323         src_y=0;
00324     }else if(src_y + b_h> h){
00325         b_h = h - src_y;
00326     }
00327 
00328     if(b_w<=0 || b_h<=0) return;
00329 
00330     av_assert2(src_stride > 2*MB_SIZE + 5);
00331 
00332     if(!sliced && offset_dst)
00333         dst += src_x + src_y*dst_stride;
00334     dst8+= src_x + src_y*src_stride;
00335 //    src += src_x + src_y*src_stride;
00336 
00337     ptmp= tmp + 3*tmp_step;
00338     block[0]= ptmp;
00339     ptmp+=tmp_step;
00340     ff_snow_pred_block(s, block[0], tmp, src_stride, src_x, src_y, b_w, b_h, lt, plane_index, w, h);
00341 
00342     if(same_block(lt, rt)){
00343         block[1]= block[0];
00344     }else{
00345         block[1]= ptmp;
00346         ptmp+=tmp_step;
00347         ff_snow_pred_block(s, block[1], tmp, src_stride, src_x, src_y, b_w, b_h, rt, plane_index, w, h);
00348     }
00349 
00350     if(same_block(lt, lb)){
00351         block[2]= block[0];
00352     }else if(same_block(rt, lb)){
00353         block[2]= block[1];
00354     }else{
00355         block[2]= ptmp;
00356         ptmp+=tmp_step;
00357         ff_snow_pred_block(s, block[2], tmp, src_stride, src_x, src_y, b_w, b_h, lb, plane_index, w, h);
00358     }
00359 
00360     if(same_block(lt, rb) ){
00361         block[3]= block[0];
00362     }else if(same_block(rt, rb)){
00363         block[3]= block[1];
00364     }else if(same_block(lb, rb)){
00365         block[3]= block[2];
00366     }else{
00367         block[3]= ptmp;
00368         ff_snow_pred_block(s, block[3], tmp, src_stride, src_x, src_y, b_w, b_h, rb, plane_index, w, h);
00369     }
00370     if(sliced){
00371         s->dwt.inner_add_yblock(obmc, obmc_stride, block, b_w, b_h, src_x,src_y, src_stride, sb, add, dst8);
00372     }else{
00373         for(y=0; y<b_h; y++){
00374             //FIXME ugly misuse of obmc_stride
00375             const uint8_t *obmc1= obmc + y*obmc_stride;
00376             const uint8_t *obmc2= obmc1+ (obmc_stride>>1);
00377             const uint8_t *obmc3= obmc1+ obmc_stride*(obmc_stride>>1);
00378             const uint8_t *obmc4= obmc3+ (obmc_stride>>1);
00379             for(x=0; x<b_w; x++){
00380                 int v=   obmc1[x] * block[3][x + y*src_stride]
00381                         +obmc2[x] * block[2][x + y*src_stride]
00382                         +obmc3[x] * block[1][x + y*src_stride]
00383                         +obmc4[x] * block[0][x + y*src_stride];
00384 
00385                 v <<= 8 - LOG2_OBMC_MAX;
00386                 if(FRAC_BITS != 8){
00387                     v >>= 8 - FRAC_BITS;
00388                 }
00389                 if(add){
00390                     v += dst[x + y*dst_stride];
00391                     v = (v + (1<<(FRAC_BITS-1))) >> FRAC_BITS;
00392                     if(v&(~255)) v= ~(v>>31);
00393                     dst8[x + y*src_stride] = v;
00394                 }else{
00395                     dst[x + y*dst_stride] -= v;
00396                 }
00397             }
00398         }
00399     }
00400 }
00401 
00402 static av_always_inline void predict_slice(SnowContext *s, IDWTELEM *buf, int plane_index, int add, int mb_y){
00403     Plane *p= &s->plane[plane_index];
00404     const int mb_w= s->b_width  << s->block_max_depth;
00405     const int mb_h= s->b_height << s->block_max_depth;
00406     int x, y, mb_x;
00407     int block_size = MB_SIZE >> s->block_max_depth;
00408     int block_w    = plane_index ? block_size>>s->chroma_h_shift : block_size;
00409     int block_h    = plane_index ? block_size>>s->chroma_v_shift : block_size;
00410     const uint8_t *obmc  = plane_index ? ff_obmc_tab[s->block_max_depth+s->chroma_h_shift] : ff_obmc_tab[s->block_max_depth];
00411     const int obmc_stride= plane_index ? (2*block_size)>>s->chroma_h_shift : 2*block_size;
00412     int ref_stride= s->current_picture.linesize[plane_index];
00413     uint8_t *dst8= s->current_picture.data[plane_index];
00414     int w= p->width;
00415     int h= p->height;
00416     av_assert2(s->chroma_h_shift == s->chroma_v_shift); // obmc params assume squares
00417     if(s->keyframe || (s->avctx->debug&512)){
00418         if(mb_y==mb_h)
00419             return;
00420 
00421         if(add){
00422             for(y=block_h*mb_y; y<FFMIN(h,block_h*(mb_y+1)); y++){
00423                 for(x=0; x<w; x++){
00424                     int v= buf[x + y*w] + (128<<FRAC_BITS) + (1<<(FRAC_BITS-1));
00425                     v >>= FRAC_BITS;
00426                     if(v&(~255)) v= ~(v>>31);
00427                     dst8[x + y*ref_stride]= v;
00428                 }
00429             }
00430         }else{
00431             for(y=block_h*mb_y; y<FFMIN(h,block_h*(mb_y+1)); y++){
00432                 for(x=0; x<w; x++){
00433                     buf[x + y*w]-= 128<<FRAC_BITS;
00434                 }
00435             }
00436         }
00437 
00438         return;
00439     }
00440 
00441     for(mb_x=0; mb_x<=mb_w; mb_x++){
00442         add_yblock(s, 0, NULL, buf, dst8, obmc,
00443                    block_w*mb_x - block_w/2,
00444                    block_h*mb_y - block_h/2,
00445                    block_w, block_h,
00446                    w, h,
00447                    w, ref_stride, obmc_stride,
00448                    mb_x - 1, mb_y - 1,
00449                    add, 1, plane_index);
00450     }
00451 }
00452 
00453 static av_always_inline void predict_plane(SnowContext *s, IDWTELEM *buf, int plane_index, int add){
00454     const int mb_h= s->b_height << s->block_max_depth;
00455     int mb_y;
00456     for(mb_y=0; mb_y<=mb_h; mb_y++)
00457         predict_slice(s, buf, plane_index, add, mb_y);
00458 }
00459 
00460 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){
00461     const int w= s->b_width << s->block_max_depth;
00462     const int rem_depth= s->block_max_depth - level;
00463     const int index= (x + y*w) << rem_depth;
00464     const int block_w= 1<<rem_depth;
00465     const int block_h= 1<<rem_depth; //FIXME "w!=h"
00466     BlockNode block;
00467     int i,j;
00468 
00469     block.color[0]= l;
00470     block.color[1]= cb;
00471     block.color[2]= cr;
00472     block.mx= mx;
00473     block.my= my;
00474     block.ref= ref;
00475     block.type= type;
00476     block.level= level;
00477 
00478     for(j=0; j<block_h; j++){
00479         for(i=0; i<block_w; i++){
00480             s->block[index + i + j*w]= block;
00481         }
00482     }
00483 }
00484 
00485 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){
00486     SnowContext *s = c->avctx->priv_data;
00487     const int offset[3]= {
00488           y*c->  stride + x,
00489         ((y*c->uvstride + x)>>s->chroma_h_shift),
00490         ((y*c->uvstride + x)>>s->chroma_h_shift),
00491     };
00492     int i;
00493     for(i=0; i<3; i++){
00494         c->src[0][i]= src [i];
00495         c->ref[0][i]= ref [i] + offset[i];
00496     }
00497     av_assert2(!ref_index);
00498 }
00499 
00500 
00501 /* bitstream functions */
00502 
00503 extern const int8_t ff_quant3bA[256];
00504 
00505 #define QEXPSHIFT (7-FRAC_BITS+8) //FIXME try to change this to 0
00506 
00507 static inline void put_symbol(RangeCoder *c, uint8_t *state, int v, int is_signed){
00508     int i;
00509 
00510     if(v){
00511         const int a= FFABS(v);
00512         const int e= av_log2(a);
00513         const int el= FFMIN(e, 10);
00514         put_rac(c, state+0, 0);
00515 
00516         for(i=0; i<el; i++){
00517             put_rac(c, state+1+i, 1);  //1..10
00518         }
00519         for(; i<e; i++){
00520             put_rac(c, state+1+9, 1);  //1..10
00521         }
00522         put_rac(c, state+1+FFMIN(i,9), 0);
00523 
00524         for(i=e-1; i>=el; i--){
00525             put_rac(c, state+22+9, (a>>i)&1); //22..31
00526         }
00527         for(; i>=0; i--){
00528             put_rac(c, state+22+i, (a>>i)&1); //22..31
00529         }
00530 
00531         if(is_signed)
00532             put_rac(c, state+11 + el, v < 0); //11..21
00533     }else{
00534         put_rac(c, state+0, 1);
00535     }
00536 }
00537 
00538 static inline int get_symbol(RangeCoder *c, uint8_t *state, int is_signed){
00539     if(get_rac(c, state+0))
00540         return 0;
00541     else{
00542         int i, e, a;
00543         e= 0;
00544         while(get_rac(c, state+1 + FFMIN(e,9))){ //1..10
00545             e++;
00546         }
00547 
00548         a= 1;
00549         for(i=e-1; i>=0; i--){
00550             a += a + get_rac(c, state+22 + FFMIN(i,9)); //22..31
00551         }
00552 
00553         e= -(is_signed && get_rac(c, state+11 + FFMIN(e,10))); //11..21
00554         return (a^e)-e;
00555     }
00556 }
00557 
00558 static inline void put_symbol2(RangeCoder *c, uint8_t *state, int v, int log2){
00559     int i;
00560     int r= log2>=0 ? 1<<log2 : 1;
00561 
00562     av_assert2(v>=0);
00563     av_assert2(log2>=-4);
00564 
00565     while(v >= r){
00566         put_rac(c, state+4+log2, 1);
00567         v -= r;
00568         log2++;
00569         if(log2>0) r+=r;
00570     }
00571     put_rac(c, state+4+log2, 0);
00572 
00573     for(i=log2-1; i>=0; i--){
00574         put_rac(c, state+31-i, (v>>i)&1);
00575     }
00576 }
00577 
00578 static inline int get_symbol2(RangeCoder *c, uint8_t *state, int log2){
00579     int i;
00580     int r= log2>=0 ? 1<<log2 : 1;
00581     int v=0;
00582 
00583     av_assert2(log2>=-4);
00584 
00585     while(log2<28 && get_rac(c, state+4+log2)){
00586         v+= r;
00587         log2++;
00588         if(log2>0) r+=r;
00589     }
00590 
00591     for(i=log2-1; i>=0; i--){
00592         v+= get_rac(c, state+31-i)<<i;
00593     }
00594 
00595     return v;
00596 }
00597 
00598 static inline void unpack_coeffs(SnowContext *s, SubBand *b, SubBand * parent, int orientation){
00599     const int w= b->width;
00600     const int h= b->height;
00601     int x,y;
00602 
00603     int run, runs;
00604     x_and_coeff *xc= b->x_coeff;
00605     x_and_coeff *prev_xc= NULL;
00606     x_and_coeff *prev2_xc= xc;
00607     x_and_coeff *parent_xc= parent ? parent->x_coeff : NULL;
00608     x_and_coeff *prev_parent_xc= parent_xc;
00609 
00610     runs= get_symbol2(&s->c, b->state[30], 0);
00611     if(runs-- > 0) run= get_symbol2(&s->c, b->state[1], 3);
00612     else           run= INT_MAX;
00613 
00614     for(y=0; y<h; y++){
00615         int v=0;
00616         int lt=0, t=0, rt=0;
00617 
00618         if(y && prev_xc->x == 0){
00619             rt= prev_xc->coeff;
00620         }
00621         for(x=0; x<w; x++){
00622             int p=0;
00623             const int l= v;
00624 
00625             lt= t; t= rt;
00626 
00627             if(y){
00628                 if(prev_xc->x <= x)
00629                     prev_xc++;
00630                 if(prev_xc->x == x + 1)
00631                     rt= prev_xc->coeff;
00632                 else
00633                     rt=0;
00634             }
00635             if(parent_xc){
00636                 if(x>>1 > parent_xc->x){
00637                     parent_xc++;
00638                 }
00639                 if(x>>1 == parent_xc->x){
00640                     p= parent_xc->coeff;
00641                 }
00642             }
00643             if(/*ll|*/l|lt|t|rt|p){
00644                 int context= av_log2(/*FFABS(ll) + */3*(l>>1) + (lt>>1) + (t&~1) + (rt>>1) + (p>>1));
00645 
00646                 v=get_rac(&s->c, &b->state[0][context]);
00647                 if(v){
00648                     v= 2*(get_symbol2(&s->c, b->state[context + 2], context-4) + 1);
00649                     v+=get_rac(&s->c, &b->state[0][16 + 1 + 3 + ff_quant3bA[l&0xFF] + 3*ff_quant3bA[t&0xFF]]);
00650 
00651                     xc->x=x;
00652                     (xc++)->coeff= v;
00653                 }
00654             }else{
00655                 if(!run){
00656                     if(runs-- > 0) run= get_symbol2(&s->c, b->state[1], 3);
00657                     else           run= INT_MAX;
00658                     v= 2*(get_symbol2(&s->c, b->state[0 + 2], 0-4) + 1);
00659                     v+=get_rac(&s->c, &b->state[0][16 + 1 + 3]);
00660 
00661                     xc->x=x;
00662                     (xc++)->coeff= v;
00663                 }else{
00664                     int max_run;
00665                     run--;
00666                     v=0;
00667                     av_assert2(run >= 0);
00668                     if(y) max_run= FFMIN(run, prev_xc->x - x - 2);
00669                     else  max_run= FFMIN(run, w-x-1);
00670                     if(parent_xc)
00671                         max_run= FFMIN(max_run, 2*parent_xc->x - x - 1);
00672                     av_assert2(max_run >= 0 && max_run <= run);
00673 
00674                     x+= max_run;
00675                     run-= max_run;
00676                 }
00677             }
00678         }
00679         (xc++)->x= w+1; //end marker
00680         prev_xc= prev2_xc;
00681         prev2_xc= xc;
00682 
00683         if(parent_xc){
00684             if(y&1){
00685                 while(parent_xc->x != parent->width+1)
00686                     parent_xc++;
00687                 parent_xc++;
00688                 prev_parent_xc= parent_xc;
00689             }else{
00690                 parent_xc= prev_parent_xc;
00691             }
00692         }
00693     }
00694 
00695     (xc++)->x= w+1; //end marker
00696 }
00697 
00698 #endif /* AVCODEC_SNOW_H */