libavcodec/h263.c

   1 /*
   2  * H263/MPEG4 backend for encoder and decoder
   3  * Copyright (c) 2000,2001 Fabrice Bellard
   4  * H263+ support.
   5  * Copyright (c) 2001 Juan J. Sierralta P
   6  * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
   7  *
   8  * This file is part of Libav.
   9  *
  10  * Libav is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU Lesser General Public
  12  * License as published by the Free Software Foundation; either
  13  * version 2.1 of the License, or (at your option) any later version.
  14  *
  15  * Libav is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  * Lesser General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public
  21  * License along with Libav; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  23  */
  24
  25 /**
  26  * @file
  27  * h263/mpeg4 codec.
  28  */
  29
  30 //#define DEBUG
  31 #include <limits.h>
  32
  33 #include "avcodec.h"
  34 #include "mpegvideo.h"
  35 #include "h263.h"
  36 #include "h263data.h"
  37 #include "mathops.h"
  38 #include "unary.h"
  39 #include "flv.h"
  40 #include "mpeg4video.h"
  41
  42 //#undef NDEBUG
  43 //#include <assert.h>
  44
  45 uint8_t ff_h263_static_rl_table_store[2][2][2*MAX_RUN + MAX_LEVEL + 3];
  46
  47
  48 void ff_h263_update_motion_val(MpegEncContext * s){
  49     const int mb_xy = s->mb_y * s->mb_stride + s->mb_x;
  50                //FIXME a lot of that is only needed for !low_delay
  51     const int wrap = s->b8_stride;
  52     const int xy = s->block_index[0];
  53
  54     s->current_picture.f.mbskip_table[mb_xy] = s->mb_skipped;
  55
  56     if(s->mv_type != MV_TYPE_8X8){
  57         int motion_x, motion_y;
  58         if (s->mb_intra) {
  59             motion_x = 0;
  60             motion_y = 0;
  61         } else if (s->mv_type == MV_TYPE_16X16) {
  62             motion_x = s->mv[0][0][0];
  63             motion_y = s->mv[0][0][1];
  64         } else /*if (s->mv_type == MV_TYPE_FIELD)*/ {
  65             int i;
  66             motion_x = s->mv[0][0][0] + s->mv[0][1][0];
  67             motion_y = s->mv[0][0][1] + s->mv[0][1][1];
  68             motion_x = (motion_x>>1) | (motion_x&1);
  69             for(i=0; i<2; i++){
  70                 s->p_field_mv_table[i][0][mb_xy][0]= s->mv[0][i][0];
  71                 s->p_field_mv_table[i][0][mb_xy][1]= s->mv[0][i][1];
  72             }
  73             s->current_picture.f.ref_index[0][4*mb_xy    ] =
  74             s->current_picture.f.ref_index[0][4*mb_xy + 1] = s->field_select[0][0];
  75             s->current_picture.f.ref_index[0][4*mb_xy + 2] =
  76             s->current_picture.f.ref_index[0][4*mb_xy + 3] = s->field_select[0][1];
  77         }
  78
  79         /* no update if 8X8 because it has been done during parsing */
  80         s->current_picture.f.motion_val[0][xy][0]            = motion_x;
  81         s->current_picture.f.motion_val[0][xy][1]            = motion_y;
  82         s->current_picture.f.motion_val[0][xy + 1][0]        = motion_x;
  83         s->current_picture.f.motion_val[0][xy + 1][1]        = motion_y;
  84         s->current_picture.f.motion_val[0][xy + wrap][0]     = motion_x;
  85         s->current_picture.f.motion_val[0][xy + wrap][1]     = motion_y;
  86         s->current_picture.f.motion_val[0][xy + 1 + wrap][0] = motion_x;
  87         s->current_picture.f.motion_val[0][xy + 1 + wrap][1] = motion_y;
  88     }
  89
  90     if(s->encoding){ //FIXME encoding MUST be cleaned up
  91         if (s->mv_type == MV_TYPE_8X8)
  92             s->current_picture.f.mb_type[mb_xy] = MB_TYPE_L0 | MB_TYPE_8x8;
  93         else if(s->mb_intra)
  94             s->current_picture.f.mb_type[mb_xy] = MB_TYPE_INTRA;
  95         else
  96             s->current_picture.f.mb_type[mb_xy] = MB_TYPE_L0 | MB_TYPE_16x16;
  97     }
  98 }
  99
 100 int ff_h263_pred_dc(MpegEncContext * s, int n, int16_t **dc_val_ptr)
 101 {
 102     int x, y, wrap, a, c, pred_dc;
 103     int16_t *dc_val;
 104
 105     /* find prediction */
 106     if (n < 4) {
 107         x = 2 * s->mb_x + (n & 1);
 108         y = 2 * s->mb_y + ((n & 2) >> 1);
 109         wrap = s->b8_stride;
 110         dc_val = s->dc_val[0];
 111     } else {
 112         x = s->mb_x;
 113         y = s->mb_y;
 114         wrap = s->mb_stride;
 115         dc_val = s->dc_val[n - 4 + 1];
 116     }
 117     /* B C
 118      * A X
 119      */
 120     a = dc_val[(x - 1) + (y) * wrap];
 121     c = dc_val[(x) + (y - 1) * wrap];
 122
 123     /* No prediction outside GOB boundary */
 124     if(s->first_slice_line && n!=3){
 125         if(n!=2) c= 1024;
 126         if(n!=1 && s->mb_x == s->resync_mb_x) a= 1024;
 127     }
 128     /* just DC prediction */
 129     if (a != 1024 && c != 1024)
 130         pred_dc = (a + c) >> 1;
 131     else if (a != 1024)
 132         pred_dc = a;
 133     else
 134         pred_dc = c;
 135
 136     /* we assume pred is positive */
 137     *dc_val_ptr = &dc_val[x + y * wrap];
 138     return pred_dc;
 139 }
 140
 141 void ff_h263_loop_filter(MpegEncContext * s){
 142     int qp_c;
 143     const int linesize  = s->linesize;
 144     const int uvlinesize= s->uvlinesize;
 145     const int xy = s->mb_y * s->mb_stride + s->mb_x;
 146     uint8_t *dest_y = s->dest[0];
 147     uint8_t *dest_cb= s->dest[1];
 148     uint8_t *dest_cr= s->dest[2];
 149
 150 //    if(s->pict_type==AV_PICTURE_TYPE_B && !s->readable) return;
 151
 152     /*
 153        Diag Top
 154        Left Center
 155     */
 156     if (!IS_SKIP(s->current_picture.f.mb_type[xy])) {
 157         qp_c= s->qscale;
 158         s->dsp.h263_v_loop_filter(dest_y+8*linesize  , linesize, qp_c);
 159         s->dsp.h263_v_loop_filter(dest_y+8*linesize+8, linesize, qp_c);
 160     }else
 161         qp_c= 0;
 162
 163     if(s->mb_y){
 164         int qp_dt, qp_tt, qp_tc;
 165
 166         if (IS_SKIP(s->current_picture.f.mb_type[xy - s->mb_stride]))
 167             qp_tt=0;
 168         else
 169             qp_tt = s->current_picture.f.qscale_table[xy - s->mb_stride];
 170
 171         if(qp_c)
 172             qp_tc= qp_c;
 173         else
 174             qp_tc= qp_tt;
 175
 176         if(qp_tc){
 177             const int chroma_qp= s->chroma_qscale_table[qp_tc];
 178             s->dsp.h263_v_loop_filter(dest_y  ,   linesize, qp_tc);
 179             s->dsp.h263_v_loop_filter(dest_y+8,   linesize, qp_tc);
 180
 181             s->dsp.h263_v_loop_filter(dest_cb , uvlinesize, chroma_qp);
 182             s->dsp.h263_v_loop_filter(dest_cr , uvlinesize, chroma_qp);
 183         }
 184
 185         if(qp_tt)
 186             s->dsp.h263_h_loop_filter(dest_y-8*linesize+8  ,   linesize, qp_tt);
 187
 188         if(s->mb_x){
 189             if (qp_tt || IS_SKIP(s->current_picture.f.mb_type[xy - 1 - s->mb_stride]))
 190                 qp_dt= qp_tt;
 191             else
 192                 qp_dt = s->current_picture.f.qscale_table[xy - 1 - s->mb_stride];
 193
 194             if(qp_dt){
 195                 const int chroma_qp= s->chroma_qscale_table[qp_dt];
 196                 s->dsp.h263_h_loop_filter(dest_y -8*linesize  ,   linesize, qp_dt);
 197                 s->dsp.h263_h_loop_filter(dest_cb-8*uvlinesize, uvlinesize, chroma_qp);
 198                 s->dsp.h263_h_loop_filter(dest_cr-8*uvlinesize, uvlinesize, chroma_qp);
 199             }
 200         }
 201     }
 202
 203     if(qp_c){
 204         s->dsp.h263_h_loop_filter(dest_y +8,   linesize, qp_c);
 205         if(s->mb_y + 1 == s->mb_height)
 206             s->dsp.h263_h_loop_filter(dest_y+8*linesize+8,   linesize, qp_c);
 207     }
 208
 209     if(s->mb_x){
 210         int qp_lc;
 211         if (qp_c || IS_SKIP(s->current_picture.f.mb_type[xy - 1]))
 212             qp_lc= qp_c;
 213         else
 214             qp_lc = s->current_picture.f.qscale_table[xy - 1];
 215
 216         if(qp_lc){
 217             s->dsp.h263_h_loop_filter(dest_y,   linesize, qp_lc);
 218             if(s->mb_y + 1 == s->mb_height){
 219                 const int chroma_qp= s->chroma_qscale_table[qp_lc];
 220                 s->dsp.h263_h_loop_filter(dest_y +8*  linesize,   linesize, qp_lc);
 221                 s->dsp.h263_h_loop_filter(dest_cb             , uvlinesize, chroma_qp);
 222                 s->dsp.h263_h_loop_filter(dest_cr             , uvlinesize, chroma_qp);
 223             }
 224         }
 225     }
 226 }
 227
 228 void ff_h263_pred_acdc(MpegEncContext * s, int16_t *block, int n)
 229 {
 230     int x, y, wrap, a, c, pred_dc, scale, i;
 231     int16_t *dc_val, *ac_val, *ac_val1;
 232
 233     /* find prediction */
 234     if (n < 4) {
 235         x = 2 * s->mb_x + (n & 1);
 236         y = 2 * s->mb_y + (n>> 1);
 237         wrap = s->b8_stride;
 238         dc_val = s->dc_val[0];
 239         ac_val = s->ac_val[0][0];
 240         scale = s->y_dc_scale;
 241     } else {
 242         x = s->mb_x;
 243         y = s->mb_y;
 244         wrap = s->mb_stride;
 245         dc_val = s->dc_val[n - 4 + 1];
 246         ac_val = s->ac_val[n - 4 + 1][0];
 247         scale = s->c_dc_scale;
 248     }
 249
 250     ac_val += ((y) * wrap + (x)) * 16;
 251     ac_val1 = ac_val;
 252
 253     /* B C
 254      * A X
 255      */
 256     a = dc_val[(x - 1) + (y) * wrap];
 257     c = dc_val[(x) + (y - 1) * wrap];
 258
 259     /* No prediction outside GOB boundary */
 260     if(s->first_slice_line && n!=3){
 261         if(n!=2) c= 1024;
 262         if(n!=1 && s->mb_x == s->resync_mb_x) a= 1024;
 263     }
 264
 265     if (s->ac_pred) {
 266         pred_dc = 1024;
 267         if (s->h263_aic_dir) {
 268             /* left prediction */
 269             if (a != 1024) {
 270                 ac_val -= 16;
 271                 for(i=1;i<8;i++) {
 272                     block[s->dsp.idct_permutation[i<<3]] += ac_val[i];
 273                 }
 274                 pred_dc = a;
 275             }
 276         } else {
 277             /* top prediction */
 278             if (c != 1024) {
 279                 ac_val -= 16 * wrap;
 280                 for(i=1;i<8;i++) {
 281                     block[s->dsp.idct_permutation[i   ]] += ac_val[i + 8];
 282                 }
 283                 pred_dc = c;
 284             }
 285         }
 286     } else {
 287         /* just DC prediction */
 288         if (a != 1024 && c != 1024)
 289             pred_dc = (a + c) >> 1;
 290         else if (a != 1024)
 291             pred_dc = a;
 292         else
 293             pred_dc = c;
 294     }
 295
 296     /* we assume pred is positive */
 297     block[0]=block[0]*scale + pred_dc;
 298
 299     if (block[0] < 0)
 300         block[0] = 0;
 301     else
 302         block[0] |= 1;
 303
 304     /* Update AC/DC tables */
 305     dc_val[(x) + (y) * wrap] = block[0];
 306
 307     /* left copy */
 308     for(i=1;i<8;i++)
 309         ac_val1[i    ] = block[s->dsp.idct_permutation[i<<3]];
 310     /* top copy */
 311     for(i=1;i<8;i++)
 312         ac_val1[8 + i] = block[s->dsp.idct_permutation[i   ]];
 313 }
 314
 315 int16_t *ff_h263_pred_motion(MpegEncContext * s, int block, int dir,
 316                              int *px, int *py)
 317 {
 318     int wrap;
 319     int16_t *A, *B, *C, (*mot_val)[2];
 320     static const int off[4]= {2, 1, 1, -1};
 321
 322     wrap = s->b8_stride;
 323     mot_val = s->current_picture.f.motion_val[dir] + s->block_index[block];
 324
 325     A = mot_val[ - 1];
 326     /* special case for first (slice) line */
 327     if (s->first_slice_line && block<3) {
 328         // we can't just change some MVs to simulate that as we need them for the B frames (and ME)
 329         // and if we ever support non rectangular objects than we need to do a few ifs here anyway :(
 330         if(block==0){ //most common case
 331             if(s->mb_x  == s->resync_mb_x){ //rare
 332                 *px= *py = 0;
 333             }else if(s->mb_x + 1 == s->resync_mb_x && s->h263_pred){ //rare
 334                 C = mot_val[off[block] - wrap];
 335                 if(s->mb_x==0){
 336                     *px = C[0];
 337                     *py = C[1];
 338                 }else{
 339                     *px = mid_pred(A[0], 0, C[0]);
 340                     *py = mid_pred(A[1], 0, C[1]);
 341                 }
 342             }else{
 343                 *px = A[0];
 344                 *py = A[1];
 345             }
 346         }else if(block==1){
 347             if(s->mb_x + 1 == s->resync_mb_x && s->h263_pred){ //rare
 348                 C = mot_val[off[block] - wrap];
 349                 *px = mid_pred(A[0], 0, C[0]);
 350                 *py = mid_pred(A[1], 0, C[1]);
 351             }else{
 352                 *px = A[0];
 353                 *py = A[1];
 354             }
 355         }else{ /* block==2*/
 356             B = mot_val[ - wrap];
 357             C = mot_val[off[block] - wrap];
 358             if(s->mb_x == s->resync_mb_x) //rare
 359                 A[0]=A[1]=0;
 360
 361             *px = mid_pred(A[0], B[0], C[0]);
 362             *py = mid_pred(A[1], B[1], C[1]);
 363         }
 364     } else {
 365         B = mot_val[ - wrap];
 366         C = mot_val[off[block] - wrap];
 367         *px = mid_pred(A[0], B[0], C[0]);
 368         *py = mid_pred(A[1], B[1], C[1]);
 369     }
 370     return *mot_val;
 371 }
 372
 373
 374 /**
 375  * Get the GOB height based on picture height.
 376  */
 377 int ff_h263_get_gob_height(MpegEncContext *s){
 378     if (s->height <= 400)
 379         return 1;
 380     else if (s->height <= 800)
 381         return  2;
 382     else
 383         return 4;
 384 }