git.sesse.net Git - ffmpeg/blob - libavcodec/mpeg12.c

   1 /*
   2  * MPEG1 codec / MPEG2 decoder
   3  * Copyright (c) 2000,2001 Fabrice Bellard.
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  */
  19
  20 /**
  21  * @file mpeg12.c
  22  * MPEG1 codec / MPEG2 decoder.
  23  */
  24
  25 //#define DEBUG
  26 #include "avcodec.h"
  27 #include "dsputil.h"
  28 #include "mpegvideo.h"
  29
  30 #include "mpeg12data.h"
  31
  32
  33 /* Start codes. */
  34 #define SEQ_END_CODE            0x000001b7
  35 #define SEQ_START_CODE          0x000001b3
  36 #define GOP_START_CODE          0x000001b8
  37 #define PICTURE_START_CODE      0x00000100
  38 #define SLICE_MIN_START_CODE    0x00000101
  39 #define SLICE_MAX_START_CODE    0x000001af
  40 #define EXT_START_CODE          0x000001b5
  41 #define USER_START_CODE         0x000001b2
  42
  43 #define DC_VLC_BITS 9
  44 #define MV_VLC_BITS 9
  45 #define MBINCR_VLC_BITS 9
  46 #define MB_PAT_VLC_BITS 9
  47 #define MB_PTYPE_VLC_BITS 6
  48 #define MB_BTYPE_VLC_BITS 6
  49 #define TEX_VLC_BITS 9
  50
  51 static void mpeg1_encode_block(MpegEncContext *s,
  52                          DCTELEM *block,
  53                          int component);
  54 static void mpeg1_encode_motion(MpegEncContext *s, int val, int f_or_b_code);    // RAL: f_code parameter added
  55 static void mpeg1_skip_picture(MpegEncContext *s, int pict_num);
  56 static inline int mpeg1_decode_block_inter(MpegEncContext *s,
  57                               DCTELEM *block,
  58                               int n);
  59 static inline int mpeg1_decode_block_intra(MpegEncContext *s,
  60                               DCTELEM *block,
  61                               int n);
  62 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
  63                                         DCTELEM *block,
  64                                         int n);
  65 static inline int mpeg2_decode_block_intra(MpegEncContext *s,
  66                                     DCTELEM *block,
  67                                     int n);
  68 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred);
  69
  70 #ifdef CONFIG_ENCODERS
  71 static uint8_t (*mv_penalty)[MAX_MV*2+1]= NULL;
  72 static uint8_t fcode_tab[MAX_MV*2+1];
  73
  74 static uint32_t uni_mpeg1_ac_vlc_bits[64*64*2];
  75 static uint8_t  uni_mpeg1_ac_vlc_len [64*64*2];
  76 #endif
  77
  78 static void init_2d_vlc_rl(RLTable *rl)
  79 {
  80     int i;
  81
  82     init_vlc(&rl->vlc, TEX_VLC_BITS, rl->n + 2,
  83              &rl->table_vlc[0][1], 4, 2,
  84              &rl->table_vlc[0][0], 4, 2);
  85
  86
  87     rl->rl_vlc[0]= av_malloc(rl->vlc.table_size*sizeof(RL_VLC_ELEM));
  88     for(i=0; i<rl->vlc.table_size; i++){
  89         int code= rl->vlc.table[i][0];
  90         int len = rl->vlc.table[i][1];
  91         int level, run;
  92
  93         if(len==0){ // illegal code
  94             run= 65;
  95             level= MAX_LEVEL;
  96         }else if(len<0){ //more bits needed
  97             run= 0;
  98             level= code;
  99         }else{
 100             if(code==rl->n){ //esc
 101                 run= 65;
 102                 level= 0;
 103             }else if(code==rl->n+1){ //eob
 104                 run= 0;
 105                 level= 127;
 106             }else{
 107                 run=   rl->table_run  [code] + 1;
 108                 level= rl->table_level[code];
 109             }
 110         }
 111         rl->rl_vlc[0][i].len= len;
 112         rl->rl_vlc[0][i].level= level;
 113         rl->rl_vlc[0][i].run= run;
 114     }
 115 }
 116
 117 static void init_uni_ac_vlc(RLTable *rl, uint32_t *uni_ac_vlc_bits, uint8_t *uni_ac_vlc_len){
 118     int i;
 119
 120     for(i=0; i<128; i++){
 121         int level= i-64;
 122         int run;
 123         for(run=0; run<64; run++){
 124             int len, bits, code;
 125
 126             int alevel= ABS(level);
 127             int sign= (level>>31)&1;
 128
 129             if (alevel > rl->max_level[0][run])
 130                 code= 111; /*rl->n*/
 131             else
 132                 code= rl->index_run[0][run] + alevel - 1;
 133
 134             if (code < 111 /* rl->n */) {
 135                 /* store the vlc & sign at once */
 136                 len=   mpeg1_vlc[code][1]+1;
 137                 bits= (mpeg1_vlc[code][0]<<1) + sign;
 138             } else {
 139                 len=  mpeg1_vlc[111/*rl->n*/][1]+6;
 140                 bits= mpeg1_vlc[111/*rl->n*/][0]<<6;
 141
 142                 bits|= run;
 143                 if (alevel < 128) {
 144                     bits<<=8; len+=8;
 145                     bits|= level & 0xff;
 146                 } else {
 147                     bits<<=16; len+=16;
 148                     bits|= level & 0xff;
 149                     if (level < 0) {
 150                         bits|= 0x8001 + level + 255;
 151                     } else {
 152                         bits|= level & 0xffff;
 153                     }
 154                 }
 155             }
 156
 157             uni_ac_vlc_bits[UNI_AC_ENC_INDEX(run, i)]= bits;
 158             uni_ac_vlc_len [UNI_AC_ENC_INDEX(run, i)]= len;
 159         }
 160     }
 161 }
 162
 163 static void put_header(MpegEncContext *s, int header)
 164 {
 165     align_put_bits(&s->pb);
 166     put_bits(&s->pb, 16, header>>16);
 167     put_bits(&s->pb, 16, header&0xFFFF);
 168 }
 169
 170 /* put sequence header if needed */
 171 static void mpeg1_encode_sequence_header(MpegEncContext *s)
 172 {
 173         unsigned int vbv_buffer_size;
 174         unsigned int fps, v;
 175         int n, i;
 176         uint64_t time_code;
 177         float best_aspect_error= 1E10;
 178         float aspect_ratio= s->avctx->aspect_ratio;
 179
 180         if(aspect_ratio==0.0) aspect_ratio= s->width / (float)s->height; //pixel aspect 1:1 (VGA)
 181
 182         if (s->current_picture.key_frame) {
 183             /* mpeg1 header repeated every gop */
 184             put_header(s, SEQ_START_CODE);
 185
 186             /* search closest frame rate */
 187             {
 188                 int i, dmin, d;
 189                 s->frame_rate_index = 0;
 190                 dmin = 0x7fffffff;
 191                 for(i=1;i<14;i++) {
 192                     if(s->avctx->strict_std_compliance >= 0 && i>=9) break;
 193
 194                     d = abs(MPEG1_FRAME_RATE_BASE*(int64_t)s->avctx->frame_rate/s->avctx->frame_rate_base - frame_rate_tab[i]);
 195                     if (d < dmin) {
 196                         dmin = d;
 197                         s->frame_rate_index = i;
 198                     }
 199                 }
 200             }
 201
 202             put_bits(&s->pb, 12, s->width);
 203             put_bits(&s->pb, 12, s->height);
 204
 205             for(i=1; i<15; i++){
 206                 float error= mpeg1_aspect[i] - s->width/(s->height*aspect_ratio);
 207                 error= ABS(error);
 208
 209                 if(error < best_aspect_error){
 210                     best_aspect_error= error;
 211                     s->aspect_ratio_info= i;
 212                 }
 213             }
 214
 215             put_bits(&s->pb, 4, s->aspect_ratio_info);
 216             put_bits(&s->pb, 4, s->frame_rate_index);
 217             v = (s->bit_rate + 399) / 400;
 218             if (v > 0x3ffff)
 219                 v = 0x3ffff;
 220             put_bits(&s->pb, 18, v);
 221             put_bits(&s->pb, 1, 1); /* marker */
 222
 223             if(s->avctx->rc_buffer_size)
 224                 vbv_buffer_size = s->avctx->rc_buffer_size;
 225             else
 226                 /* VBV calculation: Scaled so that a VCD has the proper VBV size of 40 kilobytes */
 227                 vbv_buffer_size = (( 20 * s->bit_rate) / (1151929 / 2)) * 8 * 1024;
 228             put_bits(&s->pb, 10, (vbv_buffer_size + 16383) / 16384);
 229             put_bits(&s->pb, 1, 1); /* constrained parameter flag */
 230             put_bits(&s->pb, 1, 0); /* no custom intra matrix */
 231             put_bits(&s->pb, 1, 0); /* no custom non intra matrix */
 232
 233             put_header(s, GOP_START_CODE);
 234             put_bits(&s->pb, 1, 0); /* do drop frame */
 235             /* time code : we must convert from the real frame rate to a
 236                fake mpeg frame rate in case of low frame rate */
 237             fps = frame_rate_tab[s->frame_rate_index];
 238             time_code = (int64_t)s->fake_picture_number * MPEG1_FRAME_RATE_BASE;
 239             s->gop_picture_number = s->fake_picture_number;
 240             put_bits(&s->pb, 5, (uint32_t)((time_code / (fps * 3600)) % 24));
 241             put_bits(&s->pb, 6, (uint32_t)((time_code / (fps * 60)) % 60));
 242             put_bits(&s->pb, 1, 1);
 243             put_bits(&s->pb, 6, (uint32_t)((time_code / fps) % 60));
 244             put_bits(&s->pb, 6, (uint32_t)((time_code % fps) / MPEG1_FRAME_RATE_BASE));
 245             put_bits(&s->pb, 1, 1); /* closed gop */
 246             put_bits(&s->pb, 1, 0); /* broken link */
 247         }
 248
 249         if (s->avctx->frame_rate < (24 * s->avctx->frame_rate_base) && s->picture_number > 0) {
 250             /* insert empty P pictures to slow down to the desired
 251                frame rate. Each fake pictures takes about 20 bytes */
 252             fps = frame_rate_tab[s->frame_rate_index];
 253             n = av_rescale((int64_t)s->picture_number * s->avctx->frame_rate_base, fps, s->avctx->frame_rate) / MPEG1_FRAME_RATE_BASE - 1;
 254             while (s->fake_picture_number < n) {
 255                 mpeg1_skip_picture(s, s->fake_picture_number -
 256                                    s->gop_picture_number);
 257                 s->fake_picture_number++;
 258             }
 259
 260         }
 261 }
 262
 263 static inline void encode_mb_skip_run(MpegEncContext *s, int run){
 264     while (run >= 33) {
 265         put_bits(&s->pb, 11, 0x008);
 266         run -= 33;
 267     }
 268     put_bits(&s->pb, mbAddrIncrTable[run][1],
 269              mbAddrIncrTable[run][0]);
 270 }
 271
 272 /* insert a fake P picture */
 273 static void mpeg1_skip_picture(MpegEncContext *s, int pict_num)
 274 {
 275     /* mpeg1 picture header */
 276     put_header(s, PICTURE_START_CODE);
 277     /* temporal reference */
 278     put_bits(&s->pb, 10, pict_num & 0x3ff);
 279
 280     put_bits(&s->pb, 3, P_TYPE);
 281     put_bits(&s->pb, 16, 0xffff); /* non constant bit rate */
 282
 283     put_bits(&s->pb, 1, 1); /* integer coordinates */
 284     put_bits(&s->pb, 3, 1); /* forward_f_code */
 285
 286     put_bits(&s->pb, 1, 0); /* extra bit picture */
 287
 288     /* only one slice */
 289     put_header(s, SLICE_MIN_START_CODE);
 290     put_bits(&s->pb, 5, 1); /* quantizer scale */
 291     put_bits(&s->pb, 1, 0); /* slice extra information */
 292
 293     encode_mb_skip_run(s, 0);
 294
 295     /* empty macroblock */
 296     put_bits(&s->pb, 3, 1); /* motion only */
 297
 298     /* zero motion x & y */
 299     put_bits(&s->pb, 1, 1);
 300     put_bits(&s->pb, 1, 1);
 301
 302     /* output a number of empty slice */
 303     encode_mb_skip_run(s, s->mb_width * s->mb_height - 2);
 304
 305     /* empty macroblock */
 306     put_bits(&s->pb, 3, 1); /* motion only */
 307
 308     /* zero motion x & y */
 309     put_bits(&s->pb, 1, 1);
 310     put_bits(&s->pb, 1, 1);
 311 }
 312
 313 static void common_init(MpegEncContext *s)
 314 {
 315     s->y_dc_scale_table=
 316     s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
 317 }
 318
 319 #ifdef CONFIG_ENCODERS
 320
 321 void ff_mpeg1_encode_slice_header(MpegEncContext *s){
 322     put_header(s, SLICE_MIN_START_CODE + s->mb_y);
 323     put_bits(&s->pb, 5, s->qscale); /* quantizer scale */
 324     put_bits(&s->pb, 1, 0); /* slice extra information */
 325 }
 326
 327 void ff_mpeg1_clean_buffers(MpegEncContext *s){
 328     s->last_dc[0] = 1 << (7 + s->intra_dc_precision);
 329     s->last_dc[1] = s->last_dc[0];
 330     s->last_dc[2] = s->last_dc[0];
 331     memset(s->last_mv, 0, sizeof(s->last_mv));
 332 }
 333
 334 void mpeg1_encode_picture_header(MpegEncContext *s, int picture_number)
 335 {
 336     mpeg1_encode_sequence_header(s);
 337
 338     /* mpeg1 picture header */
 339     put_header(s, PICTURE_START_CODE);
 340     /* temporal reference */
 341
 342     // RAL: s->picture_number instead of s->fake_picture_number
 343     put_bits(&s->pb, 10, (s->picture_number -
 344                           s->gop_picture_number) & 0x3ff);
 345     s->fake_picture_number++;
 346
 347     put_bits(&s->pb, 3, s->pict_type);
 348     put_bits(&s->pb, 16, 0xffff); /* non constant bit rate */
 349
 350     // RAL: Forward f_code also needed for B frames
 351     if (s->pict_type == P_TYPE || s->pict_type == B_TYPE) {
 352         put_bits(&s->pb, 1, 0); /* half pel coordinates */
 353         put_bits(&s->pb, 3, s->f_code); /* forward_f_code */
 354     }
 355
 356     // RAL: Backward f_code necessary for B frames
 357     if (s->pict_type == B_TYPE) {
 358         put_bits(&s->pb, 1, 0); /* half pel coordinates */
 359         put_bits(&s->pb, 3, s->b_code); /* backward_f_code */
 360         }
 361
 362     put_bits(&s->pb, 1, 0); /* extra bit picture */
 363
 364     s->mb_y=0;
 365     ff_mpeg1_encode_slice_header(s);
 366 }
 367
 368 void mpeg1_encode_mb(MpegEncContext *s,
 369                      DCTELEM block[6][64],
 370                      int motion_x, int motion_y)
 371 {
 372     int i, cbp;
 373     const int mb_x = s->mb_x;
 374     const int mb_y = s->mb_y;
 375     const int first_mb= mb_x == s->resync_mb_x && mb_y == s->resync_mb_y;
 376
 377     /* compute cbp */
 378     cbp = 0;
 379     for(i=0;i<6;i++) {
 380         if (s->block_last_index[i] >= 0)
 381             cbp |= 1 << (5 - i);
 382     }
 383
 384     if (cbp == 0 && !first_mb && (mb_x != s->mb_width - 1 || mb_y != s->mb_height - 1) &&
 385         ((s->pict_type == P_TYPE && (motion_x | motion_y) == 0) ||
 386         (s->pict_type == B_TYPE && s->mv_dir == s->last_mv_dir && (((s->mv_dir & MV_DIR_FORWARD) ? ((s->mv[0][0][0] - s->last_mv[0][0][0])|(s->mv[0][0][1] - s->last_mv[0][0][1])) : 0) |
 387         ((s->mv_dir & MV_DIR_BACKWARD) ? ((s->mv[1][0][0] - s->last_mv[1][0][0])|(s->mv[1][0][1] - s->last_mv[1][0][1])) : 0)) == 0))) {
 388         s->mb_skip_run++;
 389         s->qscale -= s->dquant;
 390         s->skip_count++;
 391         s->misc_bits++;
 392         s->last_bits++;
 393     } else {
 394         if(first_mb){
 395             assert(s->mb_skip_run == 0);
 396             encode_mb_skip_run(s, s->mb_x);
 397         }else{
 398             encode_mb_skip_run(s, s->mb_skip_run);
 399         }
 400
 401         if (s->pict_type == I_TYPE) {
 402             if(s->dquant && cbp){
 403                 put_bits(&s->pb, 2, 1); /* macroblock_type : macroblock_quant = 1 */
 404                 put_bits(&s->pb, 5, s->qscale);
 405             }else{
 406                 put_bits(&s->pb, 1, 1); /* macroblock_type : macroblock_quant = 0 */
 407                 s->qscale -= s->dquant;
 408             }
 409             s->misc_bits+= get_bits_diff(s);
 410             s->i_count++;
 411         } else if (s->mb_intra) {
 412             if(s->dquant && cbp){
 413                 put_bits(&s->pb, 6, 0x01);
 414                 put_bits(&s->pb, 5, s->qscale);
 415             }else{
 416                 put_bits(&s->pb, 5, 0x03);
 417                 s->qscale -= s->dquant;
 418             }
 419             s->misc_bits+= get_bits_diff(s);
 420             s->i_count++;
 421             s->last_mv[0][0][0] =
 422             s->last_mv[0][0][1] = 0;
 423         } else if (s->pict_type == P_TYPE) {
 424                 if (cbp != 0) {
 425                     if (motion_x == 0 && motion_y == 0) {
 426                         if(s->dquant){
 427                             put_bits(&s->pb, 5, 1); /* macroblock_pattern & quant */
 428                             put_bits(&s->pb, 5, s->qscale);
 429                         }else{
 430                             put_bits(&s->pb, 2, 1); /* macroblock_pattern only */
 431                         }
 432                         s->misc_bits+= get_bits_diff(s);
 433                         put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
 434                     } else {
 435                         if(s->dquant){
 436                             put_bits(&s->pb, 5, 2); /* motion + cbp */
 437                             put_bits(&s->pb, 5, s->qscale);
 438                         }else{
 439                             put_bits(&s->pb, 1, 1); /* motion + cbp */
 440                         }
 441                         s->misc_bits+= get_bits_diff(s);
 442                         mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0], s->f_code);    // RAL: f_code parameter added
 443                         mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1], s->f_code);    // RAL: f_code parameter added
 444                         s->mv_bits+= get_bits_diff(s);
 445                         put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
 446                     }
 447                 } else {
 448                     put_bits(&s->pb, 3, 1); /* motion only */
 449                     mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0], s->f_code);    // RAL: f_code parameter added
 450                     mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1], s->f_code);    // RAL: f_code parameter added
 451                     s->qscale -= s->dquant;
 452                     s->mv_bits+= get_bits_diff(s);
 453                 }
 454                 s->f_count++;
 455         } else
 456             {    // RAL: All the following bloc added for B frames:
 457                 if (cbp != 0)
 458                     {    // With coded bloc pattern
 459                     if (s->mv_dir == (MV_DIR_FORWARD | MV_DIR_BACKWARD))
 460                         {    // Bi-directional motion
 461                         if (s->dquant)
 462                             {    // With QScale
 463                             put_bits(&s->pb, 5, 2);
 464                             put_bits(&s->pb, 5, s->qscale);
 465                             }
 466                         else    // Without QScale
 467                             put_bits(&s->pb, 2, 3);
 468                         s->misc_bits += get_bits_diff(s);
 469                         mpeg1_encode_motion(s, s->mv[0][0][0] - s->last_mv[0][0][0], s->f_code);
 470                         mpeg1_encode_motion(s, s->mv[0][0][1] - s->last_mv[0][0][1], s->f_code);
 471                         mpeg1_encode_motion(s, s->mv[1][0][0] - s->last_mv[1][0][0], s->b_code);
 472                         mpeg1_encode_motion(s, s->mv[1][0][1] - s->last_mv[1][0][1], s->b_code);
 473                         s->b_count++;
 474                         s->f_count++;
 475                         s->mv_bits += get_bits_diff(s);
 476                         put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
 477                         }
 478                     else if (s->mv_dir == MV_DIR_BACKWARD)
 479                         {    // Backward motion
 480                         if (s->dquant)
 481                             {    // With QScale
 482                             put_bits(&s->pb, 6, 2);
 483                             put_bits(&s->pb, 5, s->qscale);
 484                             }
 485                         else    // Without QScale
 486                             put_bits(&s->pb, 3, 3);
 487                         s->misc_bits += get_bits_diff(s);
 488                         mpeg1_encode_motion(s, motion_x - s->last_mv[1][0][0], s->b_code);
 489                         mpeg1_encode_motion(s, motion_y - s->last_mv[1][0][1], s->b_code);
 490                         s->b_count++;
 491                         s->mv_bits += get_bits_diff(s);
 492                         put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
 493                         }
 494                     else if (s->mv_dir == MV_DIR_FORWARD)
 495                         {    // Forward motion
 496                         if (s->dquant)
 497                             {    // With QScale
 498                             put_bits(&s->pb, 6, 3);
 499                             put_bits(&s->pb, 5, s->qscale);
 500                             }
 501                         else    // Without QScale
 502                             put_bits(&s->pb, 4, 3);
 503                         s->misc_bits += get_bits_diff(s);
 504                         mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0], s->f_code);
 505                         mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1], s->f_code);
 506                         s->f_count++;
 507                         s->mv_bits += get_bits_diff(s);
 508                         put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
 509                         }
 510                     }
 511                 else
 512                     {    // No coded bloc pattern
 513                     if (s->mv_dir == (MV_DIR_FORWARD | MV_DIR_BACKWARD))
 514                         {    // Bi-directional motion
 515                         put_bits(&s->pb, 2, 2); /* backward & forward motion */
 516                         mpeg1_encode_motion(s, s->mv[0][0][0] - s->last_mv[0][0][0], s->f_code);
 517                         mpeg1_encode_motion(s, s->mv[0][0][1] - s->last_mv[0][0][1], s->f_code);
 518                         mpeg1_encode_motion(s, s->mv[1][0][0] - s->last_mv[1][0][0], s->b_code);
 519                         mpeg1_encode_motion(s, s->mv[1][0][1] - s->last_mv[1][0][1], s->b_code);
 520                         s->b_count++;
 521                         s->f_count++;
 522                         }
 523                     else if (s->mv_dir == MV_DIR_BACKWARD)
 524                         {    // Backward motion
 525                         put_bits(&s->pb, 3, 2); /* backward motion only */
 526                         mpeg1_encode_motion(s, motion_x - s->last_mv[1][0][0], s->b_code);
 527                         mpeg1_encode_motion(s, motion_y - s->last_mv[1][0][1], s->b_code);
 528                         s->b_count++;
 529                         }
 530                     else if (s->mv_dir == MV_DIR_FORWARD)
 531                         {    // Forward motion
 532                         put_bits(&s->pb, 4, 2); /* forward motion only */
 533                         mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0], s->f_code);
 534                         mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1], s->f_code);
 535                         s->f_count++;
 536                         }
 537                     s->qscale -= s->dquant;
 538                     s->mv_bits += get_bits_diff(s);
 539                     }
 540             // End of bloc from RAL
 541             }
 542         for(i=0;i<6;i++) {
 543             if (cbp & (1 << (5 - i))) {
 544                 mpeg1_encode_block(s, block[i], i);
 545             }
 546         }
 547         s->mb_skip_run = 0;
 548         if(s->mb_intra)
 549             s->i_tex_bits+= get_bits_diff(s);
 550         else
 551             s->p_tex_bits+= get_bits_diff(s);
 552     }
 553
 554     // RAL: By this:
 555     if (s->mv_dir & MV_DIR_FORWARD)
 556         {
 557         s->last_mv[0][0][0]= s->mv[0][0][0];
 558         s->last_mv[0][0][1]= s->mv[0][0][1];
 559         }
 560     if (s->mv_dir & MV_DIR_BACKWARD)
 561         {
 562         s->last_mv[1][0][0]= s->mv[1][0][0];
 563         s->last_mv[1][0][1]= s->mv[1][0][1];
 564         }
 565 }
 566
 567 // RAL: Parameter added: f_or_b_code
 568 static void mpeg1_encode_motion(MpegEncContext *s, int val, int f_or_b_code)
 569 {
 570     int code, bit_size, l, m, bits, range, sign;
 571
 572     if (val == 0) {
 573         /* zero vector */
 574         code = 0;
 575         put_bits(&s->pb,
 576                  mbMotionVectorTable[0][1],
 577                  mbMotionVectorTable[0][0]);
 578     } else {
 579         bit_size = f_or_b_code - 1;
 580         range = 1 << bit_size;
 581         /* modulo encoding */
 582         l = 16 * range;
 583         m = 2 * l;
 584         if (val < -l) {
 585             val += m;
 586         } else if (val >= l) {
 587             val -= m;
 588         }
 589
 590         if (val >= 0) {
 591             val--;
 592             code = (val >> bit_size) + 1;
 593             bits = val & (range - 1);
 594             sign = 0;
 595         } else {
 596             val = -val;
 597             val--;
 598             code = (val >> bit_size) + 1;
 599             bits = val & (range - 1);
 600             sign = 1;
 601         }
 602
 603         assert(code > 0 && code <= 16);
 604
 605         put_bits(&s->pb,
 606                  mbMotionVectorTable[code][1],
 607                  mbMotionVectorTable[code][0]);
 608
 609         put_bits(&s->pb, 1, sign);
 610         if (bit_size > 0) {
 611             put_bits(&s->pb, bit_size, bits);
 612         }
 613     }
 614 }
 615
 616 void ff_mpeg1_encode_init(MpegEncContext *s)
 617 {
 618     static int done=0;
 619
 620     common_init(s);
 621
 622     if(!done){
 623         int f_code;
 624         int mv;
 625         int i;
 626
 627         done=1;
 628         init_rl(&rl_mpeg1);
 629
 630         for(i=0; i<64; i++)
 631         {
 632                 mpeg1_max_level[0][i]= rl_mpeg1.max_level[0][i];
 633                 mpeg1_index_run[0][i]= rl_mpeg1.index_run[0][i];
 634         }
 635
 636         init_uni_ac_vlc(&rl_mpeg1, uni_mpeg1_ac_vlc_bits, uni_mpeg1_ac_vlc_len);
 637
 638         /* build unified dc encoding tables */
 639         for(i=-255; i<256; i++)
 640         {
 641                 int adiff, index;
 642                 int bits, code;
 643                 int diff=i;
 644
 645                 adiff = ABS(diff);
 646                 if(diff<0) diff--;
 647                 index = vlc_dc_table[adiff];
 648
 649                 bits= vlc_dc_lum_bits[index] + index;
 650                 code= (vlc_dc_lum_code[index]<<index) + (diff & ((1 << index) - 1));
 651                 mpeg1_lum_dc_uni[i+255]= bits + (code<<8);
 652
 653                 bits= vlc_dc_chroma_bits[index] + index;
 654                 code= (vlc_dc_chroma_code[index]<<index) + (diff & ((1 << index) - 1));
 655                 mpeg1_chr_dc_uni[i+255]= bits + (code<<8);
 656         }
 657
 658         mv_penalty= av_mallocz( sizeof(uint8_t)*(MAX_FCODE+1)*(2*MAX_MV+1) );
 659
 660         for(f_code=1; f_code<=MAX_FCODE; f_code++){
 661             for(mv=-MAX_MV; mv<=MAX_MV; mv++){
 662                 int len;
 663
 664                 if(mv==0) len= mbMotionVectorTable[0][1];
 665                 else{
 666                     int val, bit_size, range, code;
 667
 668                     bit_size = s->f_code - 1;
 669                     range = 1 << bit_size;
 670
 671                     val=mv;
 672                     if (val < 0)
 673                         val = -val;
 674                     val--;
 675                     code = (val >> bit_size) + 1;
 676                     if(code<17){
 677                         len= mbMotionVectorTable[code][1] + 1 + bit_size;
 678                     }else{
 679                         len= mbMotionVectorTable[16][1] + 2 + bit_size;
 680                     }
 681                 }
 682
 683                 mv_penalty[f_code][mv+MAX_MV]= len;
 684             }
 685         }
 686
 687
 688         for(f_code=MAX_FCODE; f_code>0; f_code--){
 689             for(mv=-(8<<f_code); mv<(8<<f_code); mv++){
 690                 fcode_tab[mv+MAX_MV]= f_code;
 691             }
 692         }
 693     }
 694     s->me.mv_penalty= mv_penalty;
 695     s->fcode_tab= fcode_tab;
 696     s->min_qcoeff=-255;
 697     s->max_qcoeff= 255;
 698     s->intra_ac_vlc_length=
 699     s->inter_ac_vlc_length= uni_mpeg1_ac_vlc_len;
 700 }
 701
 702 static inline void encode_dc(MpegEncContext *s, int diff, int component)
 703 {
 704     if (component == 0) {
 705         put_bits(
 706             &s->pb,
 707             mpeg1_lum_dc_uni[diff+255]&0xFF,
 708             mpeg1_lum_dc_uni[diff+255]>>8);
 709     } else {
 710         put_bits(
 711             &s->pb,
 712             mpeg1_chr_dc_uni[diff+255]&0xFF,
 713             mpeg1_chr_dc_uni[diff+255]>>8);
 714     }
 715 }
 716
 717 static void mpeg1_encode_block(MpegEncContext *s,
 718                                DCTELEM *block,
 719                                int n)
 720 {
 721     int alevel, level, last_non_zero, dc, diff, i, j, run, last_index, sign;
 722     int code, component;
 723 //    RLTable *rl = &rl_mpeg1;
 724
 725     last_index = s->block_last_index[n];
 726
 727     /* DC coef */
 728     if (s->mb_intra) {
 729         component = (n <= 3 ? 0 : n - 4 + 1);
 730         dc = block[0]; /* overflow is impossible */
 731         diff = dc - s->last_dc[component];
 732         encode_dc(s, diff, component);
 733         s->last_dc[component] = dc;
 734         i = 1;
 735     } else {
 736         /* encode the first coefficient : needs to be done here because
 737            it is handled slightly differently */
 738         level = block[0];
 739         if (abs(level) == 1) {
 740                 code = ((uint32_t)level >> 31); /* the sign bit */
 741                 put_bits(&s->pb, 2, code | 0x02);
 742                 i = 1;
 743         } else {
 744             i = 0;
 745             last_non_zero = -1;
 746             goto next_coef;
 747         }
 748     }
 749
 750     /* now quantify & encode AC coefs */
 751     last_non_zero = i - 1;
 752
 753     for(;i<=last_index;i++) {
 754         j = s->intra_scantable.permutated[i];
 755         level = block[j];
 756     next_coef:
 757 #if 0
 758         if (level != 0)
 759             dprintf("level[%d]=%d\n", i, level);
 760 #endif
 761         /* encode using VLC */
 762         if (level != 0) {
 763             run = i - last_non_zero - 1;
 764
 765             alevel= level;
 766             MASK_ABS(sign, alevel)
 767             sign&=1;
 768
 769 //            code = get_rl_index(rl, 0, run, alevel);
 770             if (alevel <= mpeg1_max_level[0][run]){
 771                 code= mpeg1_index_run[0][run] + alevel - 1;
 772                 /* store the vlc & sign at once */
 773                 put_bits(&s->pb, mpeg1_vlc[code][1]+1, (mpeg1_vlc[code][0]<<1) + sign);
 774             } else {
 775                 /* escape seems to be pretty rare <5% so i dont optimize it */
 776                 put_bits(&s->pb, mpeg1_vlc[111/*rl->n*/][1], mpeg1_vlc[111/*rl->n*/][0]);
 777                 /* escape: only clip in this case */
 778                 put_bits(&s->pb, 6, run);
 779                 if (alevel < 128) {
 780                     put_bits(&s->pb, 8, level & 0xff);
 781                 } else {
 782                     if (level < 0) {
 783                         put_bits(&s->pb, 16, 0x8001 + level + 255);
 784                     } else {
 785                         put_bits(&s->pb, 16, level & 0xffff);
 786                     }
 787                 }
 788             }
 789             last_non_zero = i;
 790         }
 791     }
 792     /* end of block */
 793     put_bits(&s->pb, 2, 0x2);
 794 }
 795 #endif //CONFIG_ENCODERS
 796
 797 /******************************************/
 798 /* decoding */
 799
 800 static VLC dc_lum_vlc;
 801 static VLC dc_chroma_vlc;
 802 static VLC mv_vlc;
 803 static VLC mbincr_vlc;
 804 static VLC mb_ptype_vlc;
 805 static VLC mb_btype_vlc;
 806 static VLC mb_pat_vlc;
 807
 808 static void init_vlcs(MpegEncContext *s)
 809 {
 810     static int done = 0;
 811
 812     if (!done) {
 813         done = 1;
 814
 815         init_vlc(&dc_lum_vlc, DC_VLC_BITS, 12,
 816                  vlc_dc_lum_bits, 1, 1,
 817                  vlc_dc_lum_code, 2, 2);
 818         init_vlc(&dc_chroma_vlc,  DC_VLC_BITS, 12,
 819                  vlc_dc_chroma_bits, 1, 1,
 820                  vlc_dc_chroma_code, 2, 2);
 821         init_vlc(&mv_vlc, MV_VLC_BITS, 17,
 822                  &mbMotionVectorTable[0][1], 2, 1,
 823                  &mbMotionVectorTable[0][0], 2, 1);
 824         init_vlc(&mbincr_vlc, MBINCR_VLC_BITS, 36,
 825                  &mbAddrIncrTable[0][1], 2, 1,
 826                  &mbAddrIncrTable[0][0], 2, 1);
 827         init_vlc(&mb_pat_vlc, MB_PAT_VLC_BITS, 63,
 828                  &mbPatTable[0][1], 2, 1,
 829                  &mbPatTable[0][0], 2, 1);
 830
 831         init_vlc(&mb_ptype_vlc, MB_PTYPE_VLC_BITS, 7,
 832                  &table_mb_ptype[0][1], 2, 1,
 833                  &table_mb_ptype[0][0], 2, 1);
 834         init_vlc(&mb_btype_vlc, MB_BTYPE_VLC_BITS, 11,
 835                  &table_mb_btype[0][1], 2, 1,
 836                  &table_mb_btype[0][0], 2, 1);
 837         init_rl(&rl_mpeg1);
 838         init_rl(&rl_mpeg2);
 839
 840         init_2d_vlc_rl(&rl_mpeg1);
 841         init_2d_vlc_rl(&rl_mpeg2);
 842     }
 843 }
 844
 845 static inline int get_dmv(MpegEncContext *s)
 846 {
 847     if(get_bits1(&s->gb))
 848         return 1 - (get_bits1(&s->gb) << 1);
 849     else
 850         return 0;
 851 }
 852
 853 static inline int get_qscale(MpegEncContext *s)
 854 {
 855     int qscale;
 856     if (s->mpeg2) {
 857         if (s->q_scale_type) {
 858             qscale = non_linear_qscale[get_bits(&s->gb, 5)];
 859         } else {
 860             qscale = get_bits(&s->gb, 5) << 1;
 861         }
 862     } else {
 863         /* for mpeg1, we use the generic unquant code */
 864         qscale = get_bits(&s->gb, 5);
 865     }
 866     return qscale;
 867 }
 868
 869 /* motion type (for mpeg2) */
 870 #define MT_FIELD 1
 871 #define MT_FRAME 2
 872 #define MT_16X8  2
 873 #define MT_DMV   3
 874
 875 static int mpeg_decode_mb(MpegEncContext *s,
 876                           DCTELEM block[6][64])
 877 {
 878     int i, j, k, cbp, val, mb_type, motion_type;
 879
 880     dprintf("decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
 881
 882     assert(s->mb_skiped==0);
 883
 884     if (s->mb_skip_run-- != 0) {
 885         if(s->pict_type == I_TYPE){
 886             fprintf(stderr, "skiped MB in I frame at %d %d\n", s->mb_x, s->mb_y);
 887             return -1;
 888         }
 889
 890         /* skip mb */
 891         s->mb_intra = 0;
 892         for(i=0;i<6;i++)
 893             s->block_last_index[i] = -1;
 894         s->mv_type = MV_TYPE_16X16;
 895         if (s->pict_type == P_TYPE) {
 896             /* if P type, zero motion vector is implied */
 897             s->mv_dir = MV_DIR_FORWARD;
 898             s->mv[0][0][0] = s->mv[0][0][1] = 0;
 899             s->last_mv[0][0][0] = s->last_mv[0][0][1] = 0;
 900             s->last_mv[0][1][0] = s->last_mv[0][1][1] = 0;
 901             s->mb_skiped = 1;
 902             s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]= MB_TYPE_SKIP | MB_TYPE_L0 | MB_TYPE_16x16;
 903         } else {
 904             /* if B type, reuse previous vectors and directions */
 905             s->mv[0][0][0] = s->last_mv[0][0][0];
 906             s->mv[0][0][1] = s->last_mv[0][0][1];
 907             s->mv[1][0][0] = s->last_mv[1][0][0];
 908             s->mv[1][0][1] = s->last_mv[1][0][1];
 909
 910             s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]=
 911                 s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride - 1] | MB_TYPE_SKIP;
 912 //            assert(s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride - 1]&(MB_TYPE_16x16|MB_TYPE_16x8));
 913
 914             if((s->mv[0][0][0]|s->mv[0][0][1]|s->mv[1][0][0]|s->mv[1][0][1])==0)
 915                 s->mb_skiped = 1;
 916         }
 917
 918         return 0;
 919     }
 920
 921     switch(s->pict_type) {
 922     default:
 923     case I_TYPE:
 924         if (get_bits1(&s->gb) == 0) {
 925             if (get_bits1(&s->gb) == 0)
 926                 return -1;
 927             mb_type = MB_TYPE_QUANT | MB_TYPE_INTRA;
 928         } else {
 929             mb_type = MB_TYPE_INTRA;
 930         }
 931         break;
 932     case P_TYPE:
 933         mb_type = get_vlc2(&s->gb, mb_ptype_vlc.table, MB_PTYPE_VLC_BITS, 1);
 934         if (mb_type < 0){
 935             fprintf(stderr, "invalid mb type in P Frame at %d %d\n", s->mb_x, s->mb_y);
 936             return -1;
 937         }
 938         mb_type = ptype2mb_type[ mb_type ];
 939         break;
 940     case B_TYPE:
 941         mb_type = get_vlc2(&s->gb, mb_btype_vlc.table, MB_BTYPE_VLC_BITS, 1);
 942         if (mb_type < 0){
 943             fprintf(stderr, "invalid mb type in B Frame at %d %d\n", s->mb_x, s->mb_y);
 944             return -1;
 945         }
 946         mb_type = btype2mb_type[ mb_type ];
 947         break;
 948     }
 949     dprintf("mb_type=%x\n", mb_type);
 950 //    motion_type = 0; /* avoid warning */
 951     if (IS_INTRA(mb_type)) {
 952         /* compute dct type */
 953         if (s->picture_structure == PICT_FRAME && //FIXME add a interlaced_dct coded var?
 954             !s->frame_pred_frame_dct) {
 955             s->interlaced_dct = get_bits1(&s->gb);
 956         }
 957
 958         if (IS_QUANT(mb_type))
 959             s->qscale = get_qscale(s);
 960
 961         if (s->concealment_motion_vectors) {
 962             /* just parse them */
 963             if (s->picture_structure != PICT_FRAME)
 964                 skip_bits1(&s->gb); /* field select */
 965             mpeg_decode_motion(s, s->mpeg_f_code[0][0], 0);
 966             mpeg_decode_motion(s, s->mpeg_f_code[0][1], 0);
 967             skip_bits1(&s->gb); /* marker */
 968         }
 969         s->mb_intra = 1;
 970         memset(s->last_mv, 0, sizeof(s->last_mv)); /* reset mv prediction */
 971
 972         if (s->mpeg2) {
 973             for(i=0;i<6;i++) {
 974                 if (mpeg2_decode_block_intra(s, block[i], i) < 0)
 975                     return -1;
 976             }
 977         } else {
 978             for(i=0;i<6;i++) {
 979                 if (mpeg1_decode_block_intra(s, block[i], i) < 0)
 980                     return -1;
 981             }
 982         }
 983     } else {
 984         if (mb_type & MB_TYPE_ZERO_MV){
 985             assert(mb_type & MB_TYPE_PAT);
 986
 987             /* compute dct type */
 988             if (s->picture_structure == PICT_FRAME && //FIXME add a interlaced_dct coded var?
 989                 !s->frame_pred_frame_dct) {
 990                 s->interlaced_dct = get_bits1(&s->gb);
 991             }
 992
 993             if (IS_QUANT(mb_type))
 994                 s->qscale = get_qscale(s);
 995
 996             s->mv_dir = MV_DIR_FORWARD;
 997             s->mv_type = MV_TYPE_16X16;
 998             s->last_mv[0][0][0] = 0;
 999             s->last_mv[0][0][1] = 0;
1000             s->last_mv[0][1][0] = 0;
1001             s->last_mv[0][1][1] = 0;
1002             s->mv[0][0][0] = 0;
1003             s->mv[0][0][1] = 0;
1004         }else{
1005             assert(mb_type & MB_TYPE_L0L1);
1006 //FIXME decide if MBs in field pictures are MB_TYPE_INTERLACED
1007             /* get additionnal motion vector type */
1008             if (s->frame_pred_frame_dct)
1009                 motion_type = MT_FRAME;
1010             else{
1011                 motion_type = get_bits(&s->gb, 2);
1012             }
1013
1014             /* compute dct type */
1015             if (s->picture_structure == PICT_FRAME && //FIXME add a interlaced_dct coded var?
1016                 !s->frame_pred_frame_dct && IS_PAT(mb_type)) {
1017                 s->interlaced_dct = get_bits1(&s->gb);
1018             }
1019
1020             if (IS_QUANT(mb_type))
1021                 s->qscale = get_qscale(s);
1022
1023             /* motion vectors */
1024             s->mv_dir = 0;
1025             for(i=0;i<2;i++) {
1026                 if (USES_LIST(mb_type, i)) {
1027                     s->mv_dir |= (MV_DIR_FORWARD >> i);
1028                     dprintf("motion_type=%d\n", motion_type);
1029                     switch(motion_type) {
1030                     case MT_FRAME: /* or MT_16X8 */
1031                         if (s->picture_structure == PICT_FRAME) {
1032                             /* MT_FRAME */
1033                             mb_type |= MB_TYPE_16x16;
1034                             s->mv_type = MV_TYPE_16X16;
1035                             s->mv[i][0][0]= s->last_mv[i][0][0]= s->last_mv[i][1][0] =
1036                                 mpeg_decode_motion(s, s->mpeg_f_code[i][0], s->last_mv[i][0][0]);
1037                             s->mv[i][0][1]= s->last_mv[i][0][1]= s->last_mv[i][1][1] =
1038                                 mpeg_decode_motion(s, s->mpeg_f_code[i][1], s->last_mv[i][0][1]);
1039                             /* full_pel: only for mpeg1 */
1040                             if (s->full_pel[i]){
1041                                 s->mv[i][0][0] <<= 1;
1042                                 s->mv[i][0][1] <<= 1;
1043                             }
1044                         } else {
1045                             /* MT_16X8 */
1046                             mb_type |= MB_TYPE_16x8;
1047                             s->mv_type = MV_TYPE_16X8;
1048                             for(j=0;j<2;j++) {
1049                                 s->field_select[i][j] = get_bits1(&s->gb);
1050                                 for(k=0;k<2;k++) {
1051                                     val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
1052                                                              s->last_mv[i][j][k]);
1053                                     s->last_mv[i][j][k] = val;
1054                                     s->mv[i][j][k] = val;
1055                                 }
1056                             }
1057                         }
1058                         break;
1059                     case MT_FIELD:
1060                         s->mv_type = MV_TYPE_FIELD;
1061                         if (s->picture_structure == PICT_FRAME) {
1062                             mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
1063                             for(j=0;j<2;j++) {
1064                                 s->field_select[i][j] = get_bits1(&s->gb);
1065                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
1066                                                          s->last_mv[i][j][0]);
1067                                 s->last_mv[i][j][0] = val;
1068                                 s->mv[i][j][0] = val;
1069                                 dprintf("fmx=%d\n", val);
1070                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
1071                                                          s->last_mv[i][j][1] >> 1);
1072                                 s->last_mv[i][j][1] = val << 1;
1073                                 s->mv[i][j][1] = val;
1074                                 dprintf("fmy=%d\n", val);
1075                             }
1076                         } else {
1077                             mb_type |= MB_TYPE_16x16;
1078                             s->field_select[i][0] = get_bits1(&s->gb);
1079                             for(k=0;k<2;k++) {
1080                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
1081                                                          s->last_mv[i][0][k]);
1082                                 s->last_mv[i][0][k] = val;
1083                                 s->last_mv[i][1][k] = val;
1084                                 s->mv[i][0][k] = val;
1085                             }
1086                         }
1087                         break;
1088                     case MT_DMV:
1089                         {
1090                             int dmx, dmy, mx, my, m;
1091
1092                             mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
1093                                                     s->last_mv[i][0][0]);
1094                             s->last_mv[i][0][0] = mx;
1095                             s->last_mv[i][1][0] = mx;
1096                             dmx = get_dmv(s);
1097                             my = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
1098                                                     s->last_mv[i][0][1] >> 1);
1099                             dmy = get_dmv(s);
1100                             s->mv_type = MV_TYPE_DMV;
1101                             /* XXX: totally broken */
1102                             if (s->picture_structure == PICT_FRAME) {
1103                                 mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
1104
1105                                 s->last_mv[i][0][1] = my << 1;
1106                                 s->last_mv[i][1][1] = my << 1;
1107
1108                                 m = s->top_field_first ? 1 : 3;
1109                                 /* top -> top pred */
1110                                 s->mv[i][0][0] = mx;
1111                                 s->mv[i][0][1] = my << 1;
1112                                 s->mv[i][1][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
1113                                 s->mv[i][1][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
1114                                 m = 4 - m;
1115                                 s->mv[i][2][0] = mx;
1116                                 s->mv[i][2][1] = my << 1;
1117                                 s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
1118                                 s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
1119                             } else {
1120                                 mb_type |= MB_TYPE_16x16;
1121
1122                                 s->last_mv[i][0][1] = my;
1123                                 s->last_mv[i][1][1] = my;
1124                                 s->mv[i][0][0] = mx;
1125                                 s->mv[i][0][1] = my;
1126                                 s->mv[i][1][0] = ((mx + (mx > 0)) >> 1) + dmx;
1127                                 s->mv[i][1][1] = ((my + (my > 0)) >> 1) + dmy - 1
1128                                     /* + 2 * cur_field */;
1129                             }
1130                         }
1131                         break;
1132                     }
1133                 }
1134             }
1135         }
1136
1137         s->mb_intra = 0;
1138
1139         if (IS_PAT(mb_type)) {
1140             cbp = get_vlc2(&s->gb, mb_pat_vlc.table, MB_PAT_VLC_BITS, 1);
1141             if (cbp < 0){
1142                 fprintf(stderr, "invalid cbp at %d %d\n", s->mb_x, s->mb_y);
1143                 return -1;
1144             }
1145             cbp++;
1146
1147             if (s->mpeg2) {
1148                 for(i=0;i<6;i++) {
1149                     if (cbp & 32) {
1150                         if (mpeg2_decode_block_non_intra(s, block[i], i) < 0)
1151                             return -1;
1152                     } else {
1153                         s->block_last_index[i] = -1;
1154                     }
1155                     cbp+=cbp;
1156                 }
1157             } else {
1158                 for(i=0;i<6;i++) {
1159                     if (cbp & 32) {
1160                         if (mpeg1_decode_block_inter(s, block[i], i) < 0)
1161                             return -1;
1162                     } else {
1163                         s->block_last_index[i] = -1;
1164                     }
1165                     cbp+=cbp;
1166                 }
1167             }
1168         }else{
1169             for(i=0;i<6;i++)
1170                 s->block_last_index[i] = -1;
1171         }
1172     }
1173
1174     s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]= mb_type;
1175
1176     return 0;
1177 }
1178
1179 /* as h263, but only 17 codes */
1180 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
1181 {
1182     int code, sign, val, m, l, shift;
1183
1184     code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2);
1185     if (code == 0) {
1186         return pred;
1187     }
1188     if (code < 0) {
1189         return 0xffff;
1190     }
1191
1192     sign = get_bits1(&s->gb);
1193     shift = fcode - 1;
1194     val = (code - 1) << shift;
1195     if (shift > 0)
1196         val |= get_bits(&s->gb, shift);
1197     val++;
1198     if (sign)
1199         val = -val;
1200     val += pred;
1201
1202     /* modulo decoding */
1203     l = 1 << (shift+4);
1204     m = 2 * l;
1205     if (val < -l) {
1206         val += m;
1207     } else if (val >= l) {
1208         val -= m;
1209     }
1210     return val;
1211 }
1212
1213 static inline int decode_dc(MpegEncContext *s, int component)
1214 {
1215     int code, diff;
1216
1217     if (component == 0) {
1218         code = get_vlc2(&s->gb, dc_lum_vlc.table, DC_VLC_BITS, 2);
1219     } else {
1220         code = get_vlc2(&s->gb, dc_chroma_vlc.table, DC_VLC_BITS, 2);
1221     }
1222     if (code < 0){
1223         fprintf(stderr, "invalid dc code at %d %d\n", s->mb_x, s->mb_y);
1224         return 0xffff;
1225     }
1226     if (code == 0) {
1227         diff = 0;
1228     } else {
1229         diff = get_bits(&s->gb, code);
1230         if ((diff & (1 << (code - 1))) == 0)
1231             diff = (-1 << code) | (diff + 1);
1232     }
1233     return diff;
1234 }
1235
1236 static inline int mpeg1_decode_block_intra(MpegEncContext *s,
1237                                DCTELEM *block,
1238                                int n)
1239 {
1240     int level, dc, diff, i, j, run;
1241     int component;
1242     RLTable *rl = &rl_mpeg1;
1243     uint8_t * const scantable= s->intra_scantable.permutated;
1244     const uint16_t *quant_matrix= s->intra_matrix;
1245     const int qscale= s->qscale;
1246
1247     /* DC coef */
1248     component = (n <= 3 ? 0 : n - 4 + 1);
1249     diff = decode_dc(s, component);
1250     if (diff >= 0xffff)
1251         return -1;
1252     dc = s->last_dc[component];
1253     dc += diff;
1254     s->last_dc[component] = dc;
1255     block[0] = dc<<3;
1256     dprintf("dc=%d diff=%d\n", dc, diff);
1257     i = 0;
1258     {
1259         OPEN_READER(re, &s->gb);
1260         /* now quantify & encode AC coefs */
1261         for(;;) {
1262             UPDATE_CACHE(re, &s->gb);
1263             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2);
1264
1265             if(level == 127){
1266                 break;
1267             } else if(level != 0) {
1268                 i += run;
1269                 j = scantable[i];
1270                 level= (level*qscale*quant_matrix[j])>>3;
1271                 level= (level-1)|1;
1272                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1273                 LAST_SKIP_BITS(re, &s->gb, 1);
1274             } else {
1275                 /* escape */
1276                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1277                 UPDATE_CACHE(re, &s->gb);
1278                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
1279                 if (level == -128) {
1280                     level = SHOW_UBITS(re, &s->gb, 8) - 256; LAST_SKIP_BITS(re, &s->gb, 8);
1281                 } else if (level == 0) {
1282                     level = SHOW_UBITS(re, &s->gb, 8)      ; LAST_SKIP_BITS(re, &s->gb, 8);
1283                 }
1284                 i += run;
1285                 j = scantable[i];
1286                 if(level<0){
1287                     level= -level;
1288                     level= (level*qscale*quant_matrix[j])>>3;
1289                     level= (level-1)|1;
1290                     level= -level;
1291                 }else{
1292                     level= (level*qscale*quant_matrix[j])>>3;
1293                     level= (level-1)|1;
1294                 }
1295             }
1296             if (i > 63){
1297                 fprintf(stderr, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1298                 return -1;
1299             }
1300
1301             block[j] = level;
1302         }
1303         CLOSE_READER(re, &s->gb);
1304     }
1305     s->block_last_index[n] = i;
1306    return 0;
1307 }
1308
1309 static inline int mpeg1_decode_block_inter(MpegEncContext *s,
1310                                DCTELEM *block,
1311                                int n)
1312 {
1313     int level, i, j, run;
1314     RLTable *rl = &rl_mpeg1;
1315     uint8_t * const scantable= s->intra_scantable.permutated;
1316     const uint16_t *quant_matrix= s->inter_matrix;
1317     const int qscale= s->qscale;
1318
1319     {
1320         int v;
1321         OPEN_READER(re, &s->gb);
1322         i = -1;
1323         /* special case for the first coef. no need to add a second vlc table */
1324         UPDATE_CACHE(re, &s->gb);
1325         v= SHOW_UBITS(re, &s->gb, 2);
1326         if (v & 2) {
1327             LAST_SKIP_BITS(re, &s->gb, 2);
1328             level= (3*qscale*quant_matrix[0])>>4;
1329             level= (level-1)|1;
1330             if(v&1)
1331                 level= -level;
1332             block[0] = level;
1333             i++;
1334         }
1335
1336         /* now quantify & encode AC coefs */
1337         for(;;) {
1338             UPDATE_CACHE(re, &s->gb);
1339             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2);
1340
1341             if(level == 127){
1342                 break;
1343             } else if(level != 0) {
1344                 i += run;
1345                 j = scantable[i];
1346                 level= ((level*2+1)*qscale*quant_matrix[j])>>4;
1347                 level= (level-1)|1;
1348                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1349                 LAST_SKIP_BITS(re, &s->gb, 1);
1350             } else {
1351                 /* escape */
1352                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1353                 UPDATE_CACHE(re, &s->gb);
1354                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
1355                 if (level == -128) {
1356                     level = SHOW_UBITS(re, &s->gb, 8) - 256; LAST_SKIP_BITS(re, &s->gb, 8);
1357                 } else if (level == 0) {
1358                     level = SHOW_UBITS(re, &s->gb, 8)      ; LAST_SKIP_BITS(re, &s->gb, 8);
1359                 }
1360                 i += run;
1361                 j = scantable[i];
1362                 if(level<0){
1363                     level= -level;
1364                     level= ((level*2+1)*qscale*quant_matrix[j])>>4;
1365                     level= (level-1)|1;
1366                     level= -level;
1367                 }else{
1368                     level= ((level*2+1)*qscale*quant_matrix[j])>>4;
1369                     level= (level-1)|1;
1370                 }
1371             }
1372             if (i > 63){
1373                 fprintf(stderr, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1374                 return -1;
1375             }
1376
1377             block[j] = level;
1378         }
1379         CLOSE_READER(re, &s->gb);
1380     }
1381     s->block_last_index[n] = i;
1382     return 0;
1383 }
1384
1385 /* Also does unquantization here, since I will never support mpeg2
1386    encoding */
1387 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
1388                                DCTELEM *block,
1389                                int n)
1390 {
1391     int level, i, j, run;
1392     RLTable *rl = &rl_mpeg1;
1393     uint8_t * const scantable= s->intra_scantable.permutated;
1394     const uint16_t *quant_matrix;
1395     const int qscale= s->qscale;
1396     int mismatch;
1397
1398     mismatch = 1;
1399
1400     {
1401         int v;
1402         OPEN_READER(re, &s->gb);
1403         i = -1;
1404         if (n < 4)
1405             quant_matrix = s->inter_matrix;
1406         else
1407             quant_matrix = s->chroma_inter_matrix;
1408
1409         /* special case for the first coef. no need to add a second vlc table */
1410         UPDATE_CACHE(re, &s->gb);
1411         v= SHOW_UBITS(re, &s->gb, 2);
1412         if (v & 2) {
1413             LAST_SKIP_BITS(re, &s->gb, 2);
1414             level= (3*qscale*quant_matrix[0])>>5;
1415             if(v&1)
1416                 level= -level;
1417             block[0] = level;
1418             mismatch ^= level;
1419             i++;
1420         }
1421
1422         /* now quantify & encode AC coefs */
1423         for(;;) {
1424             UPDATE_CACHE(re, &s->gb);
1425             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2);
1426
1427             if(level == 127){
1428                 break;
1429             } else if(level != 0) {
1430                 i += run;
1431                 j = scantable[i];
1432                 level= ((level*2+1)*qscale*quant_matrix[j])>>5;
1433                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1434                 LAST_SKIP_BITS(re, &s->gb, 1);
1435             } else {
1436                 /* escape */
1437                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1438                 UPDATE_CACHE(re, &s->gb);
1439                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
1440
1441                 i += run;
1442                 j = scantable[i];
1443                 if(level<0){
1444                     level= ((-level*2+1)*qscale*quant_matrix[j])>>5;
1445                     level= -level;
1446                 }else{
1447                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
1448                 }
1449             }
1450             if (i > 63){
1451                 fprintf(stderr, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1452                 return -1;
1453             }
1454
1455             mismatch ^= level;
1456             block[j] = level;
1457         }
1458         CLOSE_READER(re, &s->gb);
1459     }
1460     block[63] ^= (mismatch & 1);
1461
1462     s->block_last_index[n] = i;
1463     return 0;
1464 }
1465
1466 static inline int mpeg2_decode_block_intra(MpegEncContext *s,
1467                                DCTELEM *block,
1468                                int n)
1469 {
1470     int level, dc, diff, i, j, run;
1471     int component;
1472     RLTable *rl;
1473     uint8_t * const scantable= s->intra_scantable.permutated;
1474     const uint16_t *quant_matrix;
1475     const int qscale= s->qscale;
1476     int mismatch;
1477
1478     /* DC coef */
1479     if (n < 4){
1480         quant_matrix = s->intra_matrix;
1481         component = 0;
1482     }else{
1483         quant_matrix = s->chroma_intra_matrix;
1484         component = n - 3;
1485     }
1486     diff = decode_dc(s, component);
1487     if (diff >= 0xffff)
1488         return -1;
1489     dc = s->last_dc[component];
1490     dc += diff;
1491     s->last_dc[component] = dc;
1492     block[0] = dc << (3 - s->intra_dc_precision);
1493     dprintf("dc=%d\n", block[0]);
1494     mismatch = block[0] ^ 1;
1495     i = 0;
1496     if (s->intra_vlc_format)
1497         rl = &rl_mpeg2;
1498     else
1499         rl = &rl_mpeg1;
1500
1501     {
1502         OPEN_READER(re, &s->gb);
1503         /* now quantify & encode AC coefs */
1504         for(;;) {
1505             UPDATE_CACHE(re, &s->gb);
1506             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2);
1507
1508             if(level == 127){
1509                 break;
1510             } else if(level != 0) {
1511                 i += run;
1512                 j = scantable[i];
1513                 level= (level*qscale*quant_matrix[j])>>4;
1514                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1515                 LAST_SKIP_BITS(re, &s->gb, 1);
1516             } else {
1517                 /* escape */
1518                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1519                 UPDATE_CACHE(re, &s->gb);
1520                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
1521                 i += run;
1522                 j = scantable[i];
1523                 if(level<0){
1524                     level= (-level*qscale*quant_matrix[j])>>4;
1525                     level= -level;
1526                 }else{
1527                     level= (level*qscale*quant_matrix[j])>>4;
1528                 }
1529             }
1530             if (i > 63){
1531                 fprintf(stderr, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1532                 return -1;
1533             }
1534
1535             mismatch^= level;
1536             block[j] = level;
1537         }
1538         CLOSE_READER(re, &s->gb);
1539     }
1540     block[63]^= mismatch&1;
1541
1542     s->block_last_index[n] = i;
1543     return 0;
1544 }
1545
1546 typedef struct Mpeg1Context {
1547     MpegEncContext mpeg_enc_ctx;
1548     int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
1549     int repeat_field; /* true if we must repeat the field */
1550 } Mpeg1Context;
1551
1552 static int mpeg_decode_init(AVCodecContext *avctx)
1553 {
1554     Mpeg1Context *s = avctx->priv_data;
1555
1556     s->mpeg_enc_ctx.flags= avctx->flags;
1557     common_init(&s->mpeg_enc_ctx);
1558     init_vlcs(&s->mpeg_enc_ctx);
1559
1560     s->mpeg_enc_ctx_allocated = 0;
1561     s->mpeg_enc_ctx.picture_number = 0;
1562     s->repeat_field = 0;
1563     s->mpeg_enc_ctx.codec_id= avctx->codec->id;
1564     return 0;
1565 }
1566
1567 /* return the 8 bit start code value and update the search
1568    state. Return -1 if no start code found */
1569 static int find_start_code(uint8_t **pbuf_ptr, uint8_t *buf_end)
1570 {
1571     uint8_t *buf_ptr;
1572     unsigned int state=0xFFFFFFFF, v;
1573     int val;
1574
1575     buf_ptr = *pbuf_ptr;
1576     while (buf_ptr < buf_end) {
1577         v = *buf_ptr++;
1578         if (state == 0x000001) {
1579             state = ((state << 8) | v) & 0xffffff;
1580             val = state;
1581             goto found;
1582         }
1583         state = ((state << 8) | v) & 0xffffff;
1584     }
1585     val = -1;
1586  found:
1587     *pbuf_ptr = buf_ptr;
1588     return val;
1589 }
1590
1591 static int mpeg1_decode_picture(AVCodecContext *avctx,
1592                                 uint8_t *buf, int buf_size)
1593 {
1594     Mpeg1Context *s1 = avctx->priv_data;
1595     MpegEncContext *s = &s1->mpeg_enc_ctx;
1596     int ref, f_code;
1597
1598     init_get_bits(&s->gb, buf, buf_size*8);
1599
1600     ref = get_bits(&s->gb, 10); /* temporal ref */
1601     s->pict_type = get_bits(&s->gb, 3);
1602     dprintf("pict_type=%d number=%d\n", s->pict_type, s->picture_number);
1603
1604     skip_bits(&s->gb, 16);
1605     if (s->pict_type == P_TYPE || s->pict_type == B_TYPE) {
1606         s->full_pel[0] = get_bits1(&s->gb);
1607         f_code = get_bits(&s->gb, 3);
1608         if (f_code == 0)
1609             return -1;
1610         s->mpeg_f_code[0][0] = f_code;
1611         s->mpeg_f_code[0][1] = f_code;
1612     }
1613     if (s->pict_type == B_TYPE) {
1614         s->full_pel[1] = get_bits1(&s->gb);
1615         f_code = get_bits(&s->gb, 3);
1616         if (f_code == 0)
1617             return -1;
1618         s->mpeg_f_code[1][0] = f_code;
1619         s->mpeg_f_code[1][1] = f_code;
1620     }
1621     s->current_picture.pict_type= s->pict_type;
1622     s->current_picture.key_frame= s->pict_type == I_TYPE;
1623
1624     s->y_dc_scale = 8;
1625     s->c_dc_scale = 8;
1626     s->first_slice = 1;
1627     return 0;
1628 }
1629
1630 static void mpeg_decode_sequence_extension(MpegEncContext *s)
1631 {
1632     int horiz_size_ext, vert_size_ext;
1633     int bit_rate_ext, vbv_buf_ext;
1634     int frame_rate_ext_n, frame_rate_ext_d;
1635     float aspect;
1636
1637     skip_bits(&s->gb, 8); /* profil and level */
1638     s->progressive_sequence = get_bits1(&s->gb); /* progressive_sequence */
1639     skip_bits(&s->gb, 2); /* chroma_format */
1640     horiz_size_ext = get_bits(&s->gb, 2);
1641     vert_size_ext = get_bits(&s->gb, 2);
1642     s->width |= (horiz_size_ext << 12);
1643     s->height |= (vert_size_ext << 12);
1644     bit_rate_ext = get_bits(&s->gb, 12);  /* XXX: handle it */
1645     s->bit_rate = ((s->bit_rate / 400) | (bit_rate_ext << 12)) * 400;
1646     skip_bits1(&s->gb); /* marker */
1647     vbv_buf_ext = get_bits(&s->gb, 8);
1648     s->low_delay = get_bits1(&s->gb);
1649     frame_rate_ext_n = get_bits(&s->gb, 2);
1650     frame_rate_ext_d = get_bits(&s->gb, 5);
1651     av_reduce(
1652         &s->avctx->frame_rate,
1653         &s->avctx->frame_rate_base,
1654         frame_rate_tab[s->frame_rate_index] * (frame_rate_ext_n+1),
1655         MPEG1_FRAME_RATE_BASE * (frame_rate_ext_d+1),
1656         1<<30);
1657
1658     dprintf("sequence extension\n");
1659     s->mpeg2 = 1;
1660     s->avctx->sub_id = 2; /* indicates mpeg2 found */
1661
1662     aspect= mpeg2_aspect[s->aspect_ratio_info];
1663     if(aspect>0.0)      s->avctx->aspect_ratio= s->width/(aspect*s->height);
1664     else if(aspect<0.0) s->avctx->aspect_ratio= -1.0/aspect;
1665 }
1666
1667 static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
1668 {
1669     int i, v, j;
1670
1671     dprintf("matrix extension\n");
1672
1673     if (get_bits1(&s->gb)) {
1674         for(i=0;i<64;i++) {
1675             v = get_bits(&s->gb, 8);
1676             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1677             s->intra_matrix[j] = v;
1678             s->chroma_intra_matrix[j] = v;
1679         }
1680     }
1681     if (get_bits1(&s->gb)) {
1682         for(i=0;i<64;i++) {
1683             v = get_bits(&s->gb, 8);
1684             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1685             s->inter_matrix[j] = v;
1686             s->chroma_inter_matrix[j] = v;
1687         }
1688     }
1689     if (get_bits1(&s->gb)) {
1690         for(i=0;i<64;i++) {
1691             v = get_bits(&s->gb, 8);
1692             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1693             s->chroma_intra_matrix[j] = v;
1694         }
1695     }
1696     if (get_bits1(&s->gb)) {
1697         for(i=0;i<64;i++) {
1698             v = get_bits(&s->gb, 8);
1699             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1700             s->chroma_inter_matrix[j] = v;
1701         }
1702     }
1703 }
1704
1705 static void mpeg_decode_picture_coding_extension(MpegEncContext *s)
1706 {
1707     s->full_pel[0] = s->full_pel[1] = 0;
1708     s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
1709     s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
1710     s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
1711     s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
1712     s->intra_dc_precision = get_bits(&s->gb, 2);
1713     s->picture_structure = get_bits(&s->gb, 2);
1714     s->top_field_first = get_bits1(&s->gb);
1715     s->frame_pred_frame_dct = get_bits1(&s->gb);
1716     s->concealment_motion_vectors = get_bits1(&s->gb);
1717     s->q_scale_type = get_bits1(&s->gb);
1718     s->intra_vlc_format = get_bits1(&s->gb);
1719     s->alternate_scan = get_bits1(&s->gb);
1720     s->repeat_first_field = get_bits1(&s->gb);
1721     s->chroma_420_type = get_bits1(&s->gb);
1722     s->progressive_frame = get_bits1(&s->gb);
1723
1724     if(s->picture_structure == PICT_FRAME)
1725         s->first_field=0;
1726     else{
1727         s->first_field ^= 1;
1728         memset(s->mbskip_table, 0, s->mb_stride*s->mb_height);
1729     }
1730
1731     if(s->alternate_scan){
1732         ff_init_scantable(s, &s->inter_scantable  , ff_alternate_vertical_scan);
1733         ff_init_scantable(s, &s->intra_scantable  , ff_alternate_vertical_scan);
1734         ff_init_scantable(s, &s->intra_h_scantable, ff_alternate_vertical_scan);
1735         ff_init_scantable(s, &s->intra_v_scantable, ff_alternate_vertical_scan);
1736     }else{
1737         ff_init_scantable(s, &s->inter_scantable  , ff_zigzag_direct);
1738         ff_init_scantable(s, &s->intra_scantable  , ff_zigzag_direct);
1739         ff_init_scantable(s, &s->intra_h_scantable, ff_alternate_horizontal_scan);
1740         ff_init_scantable(s, &s->intra_v_scantable, ff_alternate_vertical_scan);
1741     }
1742
1743     /* composite display not parsed */
1744     dprintf("intra_dc_precision=%d\n", s->intra_dc_precision);
1745     dprintf("picture_structure=%d\n", s->picture_structure);
1746     dprintf("top field first=%d\n", s->top_field_first);
1747     dprintf("repeat first field=%d\n", s->repeat_first_field);
1748     dprintf("conceal=%d\n", s->concealment_motion_vectors);
1749     dprintf("intra_vlc_format=%d\n", s->intra_vlc_format);
1750     dprintf("alternate_scan=%d\n", s->alternate_scan);
1751     dprintf("frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
1752     dprintf("progressive_frame=%d\n", s->progressive_frame);
1753 }
1754
1755 static void mpeg_decode_extension(AVCodecContext *avctx,
1756                                   uint8_t *buf, int buf_size)
1757 {
1758     Mpeg1Context *s1 = avctx->priv_data;
1759     MpegEncContext *s = &s1->mpeg_enc_ctx;
1760     int ext_type;
1761
1762     init_get_bits(&s->gb, buf, buf_size*8);
1763
1764     ext_type = get_bits(&s->gb, 4);
1765     switch(ext_type) {
1766     case 0x1:
1767         /* sequence ext */
1768         mpeg_decode_sequence_extension(s);
1769         break;
1770     case 0x3:
1771         /* quant matrix extension */
1772         mpeg_decode_quant_matrix_extension(s);
1773         break;
1774     case 0x8:
1775         /* picture extension */
1776         mpeg_decode_picture_coding_extension(s);
1777         break;
1778     }
1779 }
1780
1781 #define DECODE_SLICE_MB_ADDR_ERROR -3 //we faild decoding the mb_x/y info
1782 #define DECODE_SLICE_FATAL_ERROR -2
1783 #define DECODE_SLICE_ERROR -1
1784 #define DECODE_SLICE_OK 0
1785 #define DECODE_SLICE_EOP 1
1786
1787 /**
1788  * decodes a slice.
1789  * @return DECODE_SLICE_FATAL_ERROR if a non recoverable error occured<br>
1790  *         DECODE_SLICE_ERROR if the slice is damaged<br>
1791  *         DECODE_SLICE_OK if this slice is ok<br>
1792  *         DECODE_SLICE_EOP if the end of the picture is reached
1793  */
1794 static int mpeg_decode_slice(AVCodecContext *avctx,
1795                               AVFrame *pict,
1796                               int start_code,
1797                               uint8_t **buf, int buf_size)
1798 {
1799     Mpeg1Context *s1 = avctx->priv_data;
1800     MpegEncContext *s = &s1->mpeg_enc_ctx;
1801     int ret;
1802     const int field_pic= s->picture_structure != PICT_FRAME;
1803
1804     start_code = (start_code - 1) & 0xff;
1805     if (start_code >= s->mb_height){
1806         fprintf(stderr, "slice below image (%d >= %d)\n", start_code, s->mb_height);
1807         return DECODE_SLICE_MB_ADDR_ERROR;
1808     }
1809
1810     ff_mpeg1_clean_buffers(s);
1811     s->interlaced_dct = 0;
1812
1813     /* start frame decoding */
1814     if (s->first_slice) {
1815       if(s->first_field || s->picture_structure==PICT_FRAME){
1816         if(MPV_frame_start(s, avctx) < 0)
1817             return DECODE_SLICE_FATAL_ERROR;
1818
1819         ff_er_frame_start(s);
1820
1821         /* first check if we must repeat the frame */
1822         s->current_picture.repeat_pict = 0;
1823
1824         if (s->repeat_first_field) {
1825             if (s->progressive_sequence) {
1826                 if (s->top_field_first)
1827                     s->current_picture.repeat_pict = 4;
1828                 else
1829                     s->current_picture.repeat_pict = 2;
1830             } else if (s->progressive_frame) {
1831                 s->current_picture.repeat_pict = 1;
1832             }
1833         }
1834 //        printf("%d \n", s->current_picture.repeat_pict);
1835
1836         if(s->avctx->debug&FF_DEBUG_PICT_INFO){
1837              printf("qp:%d fc:%2d%2d%2d%2d %s %s %s %s dc:%d pstruct:%d fdct:%d cmv:%d qtype:%d ivlc:%d rff:%d %s\n",
1838                  s->qscale, s->mpeg_f_code[0][0],s->mpeg_f_code[0][1],s->mpeg_f_code[1][0],s->mpeg_f_code[1][1],
1839                  s->pict_type == I_TYPE ? "I" : (s->pict_type == P_TYPE ? "P" : (s->pict_type == B_TYPE ? "B" : "S")),
1840                  s->progressive_sequence ? "pro" :"", s->alternate_scan ? "alt" :"", s->top_field_first ? "top" :"",
1841                  s->intra_dc_precision, s->picture_structure, s->frame_pred_frame_dct, s->concealment_motion_vectors,
1842                  s->q_scale_type, s->intra_vlc_format, s->repeat_first_field, s->chroma_420_type ? "420" :"");
1843         }
1844       }else{ //second field
1845             int i;
1846
1847             if(!s->current_picture_ptr){
1848                 fprintf(stderr, "first field missing\n");
1849                 return -1;
1850             }
1851
1852             for(i=0; i<4; i++){
1853                 s->current_picture.data[i] = s->current_picture_ptr->data[i];
1854                 if(s->picture_structure == PICT_BOTTOM_FIELD){
1855                     s->current_picture.data[i] += s->current_picture_ptr->linesize[i];
1856                 }
1857             }
1858       }
1859     }
1860     s->first_slice = 0;
1861
1862     init_get_bits(&s->gb, *buf, buf_size*8);
1863
1864     s->qscale = get_qscale(s);
1865     if(s->qscale == 0){
1866         fprintf(stderr, "qscale == 0\n");
1867         return DECODE_SLICE_MB_ADDR_ERROR;
1868     }
1869
1870     /* extra slice info */
1871     while (get_bits1(&s->gb) != 0) {
1872         skip_bits(&s->gb, 8);
1873     }
1874
1875     s->mb_x=0;
1876
1877     for(;;) {
1878         int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
1879         if (code < 0){
1880             fprintf(stderr, "first mb_incr damaged\n");
1881             return DECODE_SLICE_MB_ADDR_ERROR;
1882         }
1883         if (code >= 33) {
1884             if (code == 33) {
1885                 s->mb_x += 33;
1886             }
1887             /* otherwise, stuffing, nothing to do */
1888         } else {
1889             s->mb_x += code;
1890             break;
1891         }
1892     }
1893
1894     s->resync_mb_x= s->mb_x;
1895     s->resync_mb_y= s->mb_y = start_code;
1896     s->mb_skip_run= 0;
1897
1898     for(;;) {
1899         s->dsp.clear_blocks(s->block[0]);
1900
1901         ret = mpeg_decode_mb(s, s->block);
1902
1903         dprintf("ret=%d\n", ret);
1904         if (ret < 0)
1905             return -1;
1906
1907         if(s->motion_val && s->pict_type != B_TYPE){ //note motion_val is normally NULL unless we want to extract the MVs
1908             const int wrap = s->block_wrap[0];
1909             const int xy = s->mb_x*2 + 1 + (s->mb_y*2 +1)*wrap;
1910             int motion_x, motion_y;
1911
1912             if (s->mb_intra || s->mv_type == MV_TYPE_16X16) {
1913                 motion_x = s->mv[0][0][0];
1914                 motion_y = s->mv[0][0][1];
1915             } else /*if (s->mv_type == MV_TYPE_FIELD)*/ {
1916                 motion_x = s->mv[0][0][0] + s->mv[0][1][0];
1917                 motion_y = s->mv[0][0][1] + s->mv[0][1][1];
1918                 motion_x = (motion_x>>1) | (motion_x&1);
1919             }
1920             s->motion_val[xy][0] = motion_x;
1921             s->motion_val[xy][1] = motion_y;
1922             s->motion_val[xy + 1][0] = motion_x;
1923             s->motion_val[xy + 1][1] = motion_y;
1924             s->motion_val[xy + wrap][0] = motion_x;
1925             s->motion_val[xy + wrap][1] = motion_y;
1926             s->motion_val[xy + 1 + wrap][0] = motion_x;
1927             s->motion_val[xy + 1 + wrap][1] = motion_y;
1928         }
1929
1930         MPV_decode_mb(s, s->block);
1931
1932         if (++s->mb_x >= s->mb_width) {
1933             if(s->picture_structure==PICT_FRAME){
1934                 ff_draw_horiz_band(s, 16*s->mb_y, 16);
1935             }else{
1936                 if(!s->first_field){
1937                     ff_draw_horiz_band(s, 32*s->mb_y, 32);
1938                 }
1939             }
1940
1941             s->mb_x = 0;
1942             s->mb_y++;
1943         }
1944
1945         /* skip mb handling */
1946         if (s->mb_skip_run == -1) {
1947             /* read again increment */
1948             s->mb_skip_run = 0;
1949             for(;;) {
1950                 int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
1951                 if (code < 0){
1952                     fprintf(stderr, "mb incr damaged\n");
1953                     return -1;
1954                 }
1955                 if (code >= 33) {
1956                     if (code == 33) {
1957                         s->mb_skip_run += 33;
1958                     }else if(code == 35){
1959                         if(s->mb_skip_run != 0 || show_bits(&s->gb, 15) != 0){
1960                             fprintf(stderr, "slice missmatch\n");
1961                             return -1;
1962                         }
1963                         goto eos; /* end of slice */
1964                     }
1965                     /* otherwise, stuffing, nothing to do */
1966                 } else {
1967                     s->mb_skip_run += code;
1968                     break;
1969                 }
1970             }
1971         }
1972         if(s->mb_y<<field_pic >= s->mb_height){
1973             fprintf(stderr, "slice too long\n");
1974             return DECODE_SLICE_ERROR;
1975         }
1976     }
1977 eos: //end of slice
1978 //printf("y %d %d %d %d\n", s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y);
1979     ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, AC_END|DC_END|MV_END);
1980
1981     emms_c();
1982
1983     *buf += get_bits_count(&s->gb)/8 - 1;
1984
1985 //intf("%d %d %d %d\n", s->mb_y, s->mb_height, s->pict_type, s->picture_number);
1986     /* end of slice reached */
1987     if (s->mb_y<<field_pic == s->mb_height && !s->first_field) {
1988         /* end of image */
1989
1990         if(s->mpeg2){
1991             s->current_picture_ptr->qscale_type= FF_QSCALE_TYPE_MPEG2;
1992         }else
1993             s->current_picture_ptr->qscale_type= FF_QSCALE_TYPE_MPEG1;
1994
1995         ff_er_frame_end(s);
1996
1997         MPV_frame_end(s);
1998
1999         if (s->pict_type == B_TYPE || s->low_delay) {
2000             *pict= *(AVFrame*)&s->current_picture;
2001             ff_print_debug_info(s, s->current_picture_ptr);
2002         } else {
2003             s->picture_number++;
2004             /* latency of 1 frame for I and P frames */
2005             /* XXX: use another variable than picture_number */
2006             if (s->last_picture_ptr != NULL) {
2007                 *pict= *(AVFrame*)&s->last_picture;
2008                  ff_print_debug_info(s, s->last_picture_ptr);
2009             }
2010         }
2011         return DECODE_SLICE_EOP;
2012     } else {
2013         return DECODE_SLICE_OK;
2014     }
2015 }
2016
2017 static int mpeg1_decode_sequence(AVCodecContext *avctx,
2018                                  uint8_t *buf, int buf_size)
2019 {
2020     Mpeg1Context *s1 = avctx->priv_data;
2021     MpegEncContext *s = &s1->mpeg_enc_ctx;
2022     int width, height, i, v, j;
2023     float aspect;
2024
2025     init_get_bits(&s->gb, buf, buf_size*8);
2026
2027     width = get_bits(&s->gb, 12);
2028     height = get_bits(&s->gb, 12);
2029     s->aspect_ratio_info= get_bits(&s->gb, 4);
2030     if(!s->mpeg2){
2031         aspect= mpeg1_aspect[s->aspect_ratio_info];
2032         if(aspect!=0.0) avctx->aspect_ratio= width/(aspect*height);
2033     }
2034
2035     s->frame_rate_index = get_bits(&s->gb, 4);
2036     if (s->frame_rate_index == 0)
2037         return -1;
2038     s->bit_rate = get_bits(&s->gb, 18) * 400;
2039     if (get_bits1(&s->gb) == 0) /* marker */
2040         return -1;
2041     if (width <= 0 || height <= 0 ||
2042         (width % 2) != 0 || (height % 2) != 0)
2043         return -1;
2044     if (width != s->width ||
2045         height != s->height) {
2046         /* start new mpeg1 context decoding */
2047         s->out_format = FMT_MPEG1;
2048         if (s1->mpeg_enc_ctx_allocated) {
2049             MPV_common_end(s);
2050         }
2051         s->width = width;
2052         s->height = height;
2053         avctx->has_b_frames= 1;
2054         s->avctx = avctx;
2055         avctx->width = width;
2056         avctx->height = height;
2057         av_reduce(
2058             &avctx->frame_rate,
2059             &avctx->frame_rate_base,
2060             frame_rate_tab[s->frame_rate_index],
2061             MPEG1_FRAME_RATE_BASE, //FIXME store in allready reduced form
2062             1<<30
2063             );
2064         avctx->bit_rate = s->bit_rate;
2065
2066         if (MPV_common_init(s) < 0)
2067             return -1;
2068         s1->mpeg_enc_ctx_allocated = 1;
2069     }
2070
2071     skip_bits(&s->gb, 10); /* vbv_buffer_size */
2072     skip_bits(&s->gb, 1);
2073
2074     /* get matrix */
2075     if (get_bits1(&s->gb)) {
2076         for(i=0;i<64;i++) {
2077             v = get_bits(&s->gb, 8);
2078             j = s->intra_scantable.permutated[i];
2079             s->intra_matrix[j] = v;
2080             s->chroma_intra_matrix[j] = v;
2081         }
2082 #ifdef DEBUG
2083         dprintf("intra matrix present\n");
2084         for(i=0;i<64;i++)
2085             dprintf(" %d", s->intra_matrix[s->intra_scantable.permutated[i]]);
2086         printf("\n");
2087 #endif
2088     } else {
2089         for(i=0;i<64;i++) {
2090             int j= s->dsp.idct_permutation[i];
2091             v = ff_mpeg1_default_intra_matrix[i];
2092             s->intra_matrix[j] = v;
2093             s->chroma_intra_matrix[j] = v;
2094         }
2095     }
2096     if (get_bits1(&s->gb)) {
2097         for(i=0;i<64;i++) {
2098             v = get_bits(&s->gb, 8);
2099             j = s->intra_scantable.permutated[i];
2100             s->inter_matrix[j] = v;
2101             s->chroma_inter_matrix[j] = v;
2102         }
2103 #ifdef DEBUG
2104         dprintf("non intra matrix present\n");
2105         for(i=0;i<64;i++)
2106             dprintf(" %d", s->inter_matrix[s->intra_scantable.permutated[i]]);
2107         printf("\n");
2108 #endif
2109     } else {
2110         for(i=0;i<64;i++) {
2111             int j= s->dsp.idct_permutation[i];
2112             v = ff_mpeg1_default_non_intra_matrix[i];
2113             s->inter_matrix[j] = v;
2114             s->chroma_inter_matrix[j] = v;
2115         }
2116     }
2117
2118     /* we set mpeg2 parameters so that it emulates mpeg1 */
2119     s->progressive_sequence = 1;
2120     s->progressive_frame = 1;
2121     s->picture_structure = PICT_FRAME;
2122     s->frame_pred_frame_dct = 1;
2123     s->mpeg2 = 0;
2124     avctx->sub_id = 1; /* indicates mpeg1 */
2125     return 0;
2126 }
2127
2128 static void mpeg_decode_user_data(AVCodecContext *avctx,
2129                                   const uint8_t *buf, int buf_size)
2130 {
2131     const uint8_t *p;
2132     int len, flags;
2133     p = buf;
2134     len = buf_size;
2135
2136     /* we parse the DTG active format information */
2137     if (len >= 5 &&
2138         p[0] == 'D' && p[1] == 'T' && p[2] == 'G' && p[3] == '1') {
2139         flags = p[4];
2140         p += 5;
2141         len -= 5;
2142         if (flags & 0x80) {
2143             /* skip event id */
2144             if (len < 2)
2145                 return;
2146             p += 2;
2147             len -= 2;
2148         }
2149         if (flags & 0x40) {
2150             if (len < 1)
2151                 return;
2152             avctx->dtg_active_format = p[0] & 0x0f;
2153         }
2154     }
2155 }
2156
2157 /**
2158  * finds the end of the current frame in the bitstream.
2159  * @return the position of the first byte of the next frame, or -1
2160  */
2161 static int mpeg1_find_frame_end(MpegEncContext *s, uint8_t *buf, int buf_size){
2162     ParseContext *pc= &s->parse_context;
2163     int i;
2164     uint32_t state;
2165
2166     state= pc->state;
2167
2168     i=0;
2169     if(!pc->frame_start_found){
2170         for(i=0; i<buf_size; i++){
2171             state= (state<<8) | buf[i];
2172             if(state >= SLICE_MIN_START_CODE && state <= SLICE_MAX_START_CODE){
2173                 i++;
2174                 pc->frame_start_found=1;
2175                 break;
2176             }
2177         }
2178     }
2179
2180     if(pc->frame_start_found){
2181         for(; i<buf_size; i++){
2182             state= (state<<8) | buf[i];
2183             if((state&0xFFFFFF00) == 0x100){
2184                 if(state < SLICE_MIN_START_CODE || state > SLICE_MAX_START_CODE){
2185                     pc->frame_start_found=0;
2186                     pc->state=-1;
2187                     return i-3;
2188                 }
2189             }
2190         }
2191     }
2192     pc->state= state;
2193     return END_NOT_FOUND;
2194 }
2195
2196 /* handle buffering and image synchronisation */
2197 static int mpeg_decode_frame(AVCodecContext *avctx,
2198                              void *data, int *data_size,
2199                              uint8_t *buf, int buf_size)
2200 {
2201     Mpeg1Context *s = avctx->priv_data;
2202     uint8_t *buf_end, *buf_ptr;
2203     int ret, start_code, input_size;
2204     AVFrame *picture = data;
2205     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2206     dprintf("fill_buffer\n");
2207
2208     *data_size = 0;
2209
2210     /* special case for last picture */
2211     if (buf_size == 0) {
2212         if (s2->picture_number > 0) {
2213             *picture= *(AVFrame*)&s2->next_picture;
2214
2215             *data_size = sizeof(AVFrame);
2216         }
2217         return 0;
2218     }
2219
2220     if(s2->flags&CODEC_FLAG_TRUNCATED){
2221         int next= mpeg1_find_frame_end(s2, buf, buf_size);
2222
2223         if( ff_combine_frame(s2, next, &buf, &buf_size) < 0 )
2224             return buf_size;
2225     }
2226
2227     buf_ptr = buf;
2228     buf_end = buf + buf_size;
2229
2230 #if 0
2231     if (s->repeat_field % 2 == 1) {
2232         s->repeat_field++;
2233         //fprintf(stderr,"\nRepeating last frame: %d -> %d! pict: %d %d", avctx->frame_number-1, avctx->frame_number,
2234         //        s2->picture_number, s->repeat_field);
2235         if (avctx->flags & CODEC_FLAG_REPEAT_FIELD) {
2236             *data_size = sizeof(AVPicture);
2237             goto the_end;
2238         }
2239     }
2240 #endif
2241     for(;;) {
2242         /* find start next code */
2243         start_code = find_start_code(&buf_ptr, buf_end);
2244         if (start_code < 0){
2245 //            printf("missing end of picture\n");
2246             return FFMAX(0, buf_ptr - buf - s2->parse_context.last_index);
2247         }
2248
2249                 /* prepare data for next start code */
2250                 input_size = buf_end - buf_ptr;
2251                 switch(start_code) {
2252                 case SEQ_START_CODE:
2253                     mpeg1_decode_sequence(avctx, buf_ptr,
2254                                           input_size);
2255                     break;
2256
2257                 case PICTURE_START_CODE:
2258                     /* we have a complete image : we try to decompress it */
2259                     mpeg1_decode_picture(avctx,
2260                                          buf_ptr, input_size);
2261                     break;
2262                 case EXT_START_CODE:
2263                     mpeg_decode_extension(avctx,
2264                                           buf_ptr, input_size);
2265                     break;
2266                 case USER_START_CODE:
2267                     mpeg_decode_user_data(avctx,
2268                                           buf_ptr, input_size);
2269                     break;
2270                 default:
2271                     if (start_code >= SLICE_MIN_START_CODE &&
2272                         start_code <= SLICE_MAX_START_CODE) {
2273
2274                         /* skip b frames if we dont have reference frames */
2275                         if(s2->last_picture_ptr==NULL && s2->pict_type==B_TYPE) break;
2276                         /* skip b frames if we are in a hurry */
2277                         if(avctx->hurry_up && s2->pict_type==B_TYPE) break;
2278                         /* skip everything if we are in a hurry>=5 */
2279                         if(avctx->hurry_up>=5) break;
2280
2281                         if (!s->mpeg_enc_ctx_allocated) break;
2282
2283                         ret = mpeg_decode_slice(avctx, picture,
2284                                                 start_code, &buf_ptr, input_size);
2285
2286                         if (ret == DECODE_SLICE_EOP) {
2287                             if(s2->last_picture_ptr) //FIXME merge with the stuff in mpeg_decode_slice
2288                                 *data_size = sizeof(AVPicture);
2289                             return FFMAX(0, buf_ptr - buf - s2->parse_context.last_index);
2290                         }else if(ret < 0){
2291                             if(ret == DECODE_SLICE_ERROR)
2292                                 ff_er_add_slice(s2, s2->resync_mb_x, s2->resync_mb_y, s2->mb_x, s2->mb_y, AC_ERROR|DC_ERROR|MV_ERROR);
2293
2294                             fprintf(stderr,"Error while decoding slice\n");
2295                             if(ret==DECODE_SLICE_FATAL_ERROR) return -1;
2296                         }
2297                     }
2298                     break;
2299                 }
2300     }
2301 }
2302
2303 static int mpeg_decode_end(AVCodecContext *avctx)
2304 {
2305     Mpeg1Context *s = avctx->priv_data;
2306
2307     if (s->mpeg_enc_ctx_allocated)
2308         MPV_common_end(&s->mpeg_enc_ctx);
2309     return 0;
2310 }
2311
2312 AVCodec mpeg_decoder = {
2313     "mpegvideo",
2314     CODEC_TYPE_VIDEO,
2315     CODEC_ID_MPEG1VIDEO,
2316     sizeof(Mpeg1Context),
2317     mpeg_decode_init,
2318     NULL,
2319     mpeg_decode_end,
2320     mpeg_decode_frame,
2321     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED,
2322 };