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   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
  77 /* simple include everything table for dc, first byte is bits number next 3 are code*/
  78 static uint32_t mpeg1_lum_dc_uni[512];
  79 static uint32_t mpeg1_chr_dc_uni[512];
  80
  81 static uint8_t mpeg1_index_run[2][64];
  82 static int8_t mpeg1_max_level[2][64];
  83 #endif
  84
  85 static void init_2d_vlc_rl(RLTable *rl)
  86 {
  87     int i;
  88
  89     init_vlc(&rl->vlc, TEX_VLC_BITS, rl->n + 2,
  90              &rl->table_vlc[0][1], 4, 2,
  91              &rl->table_vlc[0][0], 4, 2);
  92
  93
  94     rl->rl_vlc[0]= av_malloc(rl->vlc.table_size*sizeof(RL_VLC_ELEM));
  95     for(i=0; i<rl->vlc.table_size; i++){
  96         int code= rl->vlc.table[i][0];
  97         int len = rl->vlc.table[i][1];
  98         int level, run;
  99
 100         if(len==0){ // illegal code
 101             run= 65;
 102             level= MAX_LEVEL;
 103         }else if(len<0){ //more bits needed
 104             run= 0;
 105             level= code;
 106         }else{
 107             if(code==rl->n){ //esc
 108                 run= 65;
 109                 level= 0;
 110             }else if(code==rl->n+1){ //eob
 111                 run= 0;
 112                 level= 127;
 113             }else{
 114                 run=   rl->table_run  [code] + 1;
 115                 level= rl->table_level[code];
 116             }
 117         }
 118         rl->rl_vlc[0][i].len= len;
 119         rl->rl_vlc[0][i].level= level;
 120         rl->rl_vlc[0][i].run= run;
 121     }
 122 }
 123
 124 #ifdef CONFIG_ENCODERS
 125 static void init_uni_ac_vlc(RLTable *rl, uint32_t *uni_ac_vlc_bits, uint8_t *uni_ac_vlc_len){
 126     int i;
 127
 128     for(i=0; i<128; i++){
 129         int level= i-64;
 130         int run;
 131         for(run=0; run<64; run++){
 132             int len, bits, code;
 133
 134             int alevel= ABS(level);
 135             int sign= (level>>31)&1;
 136
 137             if (alevel > rl->max_level[0][run])
 138                 code= 111; /*rl->n*/
 139             else
 140                 code= rl->index_run[0][run] + alevel - 1;
 141
 142             if (code < 111 /* rl->n */) {
 143                 /* store the vlc & sign at once */
 144                 len=   mpeg1_vlc[code][1]+1;
 145                 bits= (mpeg1_vlc[code][0]<<1) + sign;
 146             } else {
 147                 len=  mpeg1_vlc[111/*rl->n*/][1]+6;
 148                 bits= mpeg1_vlc[111/*rl->n*/][0]<<6;
 149
 150                 bits|= run;
 151                 if (alevel < 128) {
 152                     bits<<=8; len+=8;
 153                     bits|= level & 0xff;
 154                 } else {
 155                     bits<<=16; len+=16;
 156                     bits|= level & 0xff;
 157                     if (level < 0) {
 158                         bits|= 0x8001 + level + 255;
 159                     } else {
 160                         bits|= level & 0xffff;
 161                     }
 162                 }
 163             }
 164
 165             uni_ac_vlc_bits[UNI_AC_ENC_INDEX(run, i)]= bits;
 166             uni_ac_vlc_len [UNI_AC_ENC_INDEX(run, i)]= len;
 167         }
 168     }
 169 }
 170
 171 static void put_header(MpegEncContext *s, int header)
 172 {
 173     align_put_bits(&s->pb);
 174     put_bits(&s->pb, 16, header>>16);
 175     put_bits(&s->pb, 16, header&0xFFFF);
 176 }
 177
 178 /* put sequence header if needed */
 179 static void mpeg1_encode_sequence_header(MpegEncContext *s)
 180 {
 181         unsigned int vbv_buffer_size;
 182         unsigned int fps, v;
 183         int n, i;
 184         uint64_t time_code;
 185         float best_aspect_error= 1E10;
 186         float aspect_ratio= s->avctx->aspect_ratio;
 187
 188         if(aspect_ratio==0.0) aspect_ratio= s->width / (float)s->height; //pixel aspect 1:1 (VGA)
 189
 190         if (s->current_picture.key_frame) {
 191             /* mpeg1 header repeated every gop */
 192             put_header(s, SEQ_START_CODE);
 193
 194             /* search closest frame rate */
 195             {
 196                 int i, dmin, d;
 197                 s->frame_rate_index = 0;
 198                 dmin = 0x7fffffff;
 199                 for(i=1;i<14;i++) {
 200                     if(s->avctx->strict_std_compliance >= 0 && i>=9) break;
 201
 202                     d = abs(MPEG1_FRAME_RATE_BASE*(int64_t)s->avctx->frame_rate/s->avctx->frame_rate_base - frame_rate_tab[i]);
 203                     if (d < dmin) {
 204                         dmin = d;
 205                         s->frame_rate_index = i;
 206                     }
 207                 }
 208             }
 209
 210             put_bits(&s->pb, 12, s->width);
 211             put_bits(&s->pb, 12, s->height);
 212
 213             for(i=1; i<15; i++){
 214                 float error= mpeg1_aspect[i] - s->width/(s->height*aspect_ratio);
 215                 error= ABS(error);
 216
 217                 if(error < best_aspect_error){
 218                     best_aspect_error= error;
 219                     s->aspect_ratio_info= i;
 220                 }
 221             }
 222
 223             put_bits(&s->pb, 4, s->aspect_ratio_info);
 224             put_bits(&s->pb, 4, s->frame_rate_index);
 225             v = (s->bit_rate + 399) / 400;
 226             if (v > 0x3ffff)
 227                 v = 0x3ffff;
 228             put_bits(&s->pb, 18, v);
 229             put_bits(&s->pb, 1, 1); /* marker */
 230
 231             if(s->avctx->rc_buffer_size)
 232                 vbv_buffer_size = s->avctx->rc_buffer_size;
 233             else
 234                 /* VBV calculation: Scaled so that a VCD has the proper VBV size of 40 kilobytes */
 235                 vbv_buffer_size = (( 20 * s->bit_rate) / (1151929 / 2)) * 8 * 1024;
 236             put_bits(&s->pb, 10, (vbv_buffer_size + 16383) / 16384);
 237             put_bits(&s->pb, 1, 1); /* constrained parameter flag */
 238             put_bits(&s->pb, 1, 0); /* no custom intra matrix */
 239             put_bits(&s->pb, 1, 0); /* no custom non intra matrix */
 240
 241             put_header(s, GOP_START_CODE);
 242             put_bits(&s->pb, 1, 0); /* do drop frame */
 243             /* time code : we must convert from the real frame rate to a
 244                fake mpeg frame rate in case of low frame rate */
 245             fps = frame_rate_tab[s->frame_rate_index];
 246             time_code = (int64_t)s->fake_picture_number * MPEG1_FRAME_RATE_BASE;
 247             s->gop_picture_number = s->fake_picture_number;
 248             put_bits(&s->pb, 5, (uint32_t)((time_code / (fps * 3600)) % 24));
 249             put_bits(&s->pb, 6, (uint32_t)((time_code / (fps * 60)) % 60));
 250             put_bits(&s->pb, 1, 1);
 251             put_bits(&s->pb, 6, (uint32_t)((time_code / fps) % 60));
 252             put_bits(&s->pb, 6, (uint32_t)((time_code % fps) / MPEG1_FRAME_RATE_BASE));
 253             put_bits(&s->pb, 1, 1); /* closed gop */
 254             put_bits(&s->pb, 1, 0); /* broken link */
 255         }
 256
 257         if (s->avctx->frame_rate < (24 * s->avctx->frame_rate_base) && s->picture_number > 0) {
 258             /* insert empty P pictures to slow down to the desired
 259                frame rate. Each fake pictures takes about 20 bytes */
 260             fps = frame_rate_tab[s->frame_rate_index];
 261             n = av_rescale((int64_t)s->picture_number * s->avctx->frame_rate_base, fps, s->avctx->frame_rate) / MPEG1_FRAME_RATE_BASE - 1;
 262             while (s->fake_picture_number < n) {
 263                 mpeg1_skip_picture(s, s->fake_picture_number -
 264                                    s->gop_picture_number);
 265                 s->fake_picture_number++;
 266             }
 267
 268         }
 269 }
 270
 271 static inline void encode_mb_skip_run(MpegEncContext *s, int run){
 272     while (run >= 33) {
 273         put_bits(&s->pb, 11, 0x008);
 274         run -= 33;
 275     }
 276     put_bits(&s->pb, mbAddrIncrTable[run][1],
 277              mbAddrIncrTable[run][0]);
 278 }
 279
 280 /* insert a fake P picture */
 281 static void mpeg1_skip_picture(MpegEncContext *s, int pict_num)
 282 {
 283     /* mpeg1 picture header */
 284     put_header(s, PICTURE_START_CODE);
 285     /* temporal reference */
 286     put_bits(&s->pb, 10, pict_num & 0x3ff);
 287
 288     put_bits(&s->pb, 3, P_TYPE);
 289     put_bits(&s->pb, 16, 0xffff); /* non constant bit rate */
 290
 291     put_bits(&s->pb, 1, 1); /* integer coordinates */
 292     put_bits(&s->pb, 3, 1); /* forward_f_code */
 293
 294     put_bits(&s->pb, 1, 0); /* extra bit picture */
 295
 296     /* only one slice */
 297     put_header(s, SLICE_MIN_START_CODE);
 298     put_bits(&s->pb, 5, 1); /* quantizer scale */
 299     put_bits(&s->pb, 1, 0); /* slice extra information */
 300
 301     encode_mb_skip_run(s, 0);
 302
 303     /* empty macroblock */
 304     put_bits(&s->pb, 3, 1); /* motion only */
 305
 306     /* zero motion x & y */
 307     put_bits(&s->pb, 1, 1);
 308     put_bits(&s->pb, 1, 1);
 309
 310     /* output a number of empty slice */
 311     encode_mb_skip_run(s, s->mb_width * s->mb_height - 2);
 312
 313     /* empty macroblock */
 314     put_bits(&s->pb, 3, 1); /* motion only */
 315
 316     /* zero motion x & y */
 317     put_bits(&s->pb, 1, 1);
 318     put_bits(&s->pb, 1, 1);
 319 }
 320 #endif
 321
 322 static void common_init(MpegEncContext *s)
 323 {
 324     s->y_dc_scale_table=
 325     s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
 326 }
 327
 328 void ff_mpeg1_clean_buffers(MpegEncContext *s){
 329     s->last_dc[0] = 1 << (7 + s->intra_dc_precision);
 330     s->last_dc[1] = s->last_dc[0];
 331     s->last_dc[2] = s->last_dc[0];
 332     memset(s->last_mv, 0, sizeof(s->last_mv));
 333 }
 334
 335 #ifdef CONFIG_ENCODERS
 336
 337 void ff_mpeg1_encode_slice_header(MpegEncContext *s){
 338     put_header(s, SLICE_MIN_START_CODE + s->mb_y);
 339     put_bits(&s->pb, 5, s->qscale); /* quantizer scale */
 340     put_bits(&s->pb, 1, 0); /* slice extra information */
 341 }
 342
 343 void mpeg1_encode_picture_header(MpegEncContext *s, int picture_number)
 344 {
 345     mpeg1_encode_sequence_header(s);
 346
 347     /* mpeg1 picture header */
 348     put_header(s, PICTURE_START_CODE);
 349     /* temporal reference */
 350
 351     // RAL: s->picture_number instead of s->fake_picture_number
 352     put_bits(&s->pb, 10, (s->picture_number -
 353                           s->gop_picture_number) & 0x3ff);
 354     s->fake_picture_number++;
 355
 356     put_bits(&s->pb, 3, s->pict_type);
 357     put_bits(&s->pb, 16, 0xffff); /* non constant bit rate */
 358
 359     // RAL: Forward f_code also needed for B frames
 360     if (s->pict_type == P_TYPE || s->pict_type == B_TYPE) {
 361         put_bits(&s->pb, 1, 0); /* half pel coordinates */
 362         put_bits(&s->pb, 3, s->f_code); /* forward_f_code */
 363     }
 364
 365     // RAL: Backward f_code necessary for B frames
 366     if (s->pict_type == B_TYPE) {
 367         put_bits(&s->pb, 1, 0); /* half pel coordinates */
 368         put_bits(&s->pb, 3, s->b_code); /* backward_f_code */
 369         }
 370
 371     put_bits(&s->pb, 1, 0); /* extra bit picture */
 372
 373     s->mb_y=0;
 374     ff_mpeg1_encode_slice_header(s);
 375 }
 376
 377 void mpeg1_encode_mb(MpegEncContext *s,
 378                      DCTELEM block[6][64],
 379                      int motion_x, int motion_y)
 380 {
 381     int i, cbp;
 382     const int mb_x = s->mb_x;
 383     const int mb_y = s->mb_y;
 384     const int first_mb= mb_x == s->resync_mb_x && mb_y == s->resync_mb_y;
 385
 386     /* compute cbp */
 387     cbp = 0;
 388     for(i=0;i<6;i++) {
 389         if (s->block_last_index[i] >= 0)
 390             cbp |= 1 << (5 - i);
 391     }
 392
 393     if (cbp == 0 && !first_mb && (mb_x != s->mb_width - 1 || mb_y != s->mb_height - 1) &&
 394         ((s->pict_type == P_TYPE && (motion_x | motion_y) == 0) ||
 395         (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) |
 396         ((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))) {
 397         s->mb_skip_run++;
 398         s->qscale -= s->dquant;
 399         s->skip_count++;
 400         s->misc_bits++;
 401         s->last_bits++;
 402     } else {
 403         if(first_mb){
 404             assert(s->mb_skip_run == 0);
 405             encode_mb_skip_run(s, s->mb_x);
 406         }else{
 407             encode_mb_skip_run(s, s->mb_skip_run);
 408         }
 409
 410         if (s->pict_type == I_TYPE) {
 411             if(s->dquant && cbp){
 412                 put_bits(&s->pb, 2, 1); /* macroblock_type : macroblock_quant = 1 */
 413                 put_bits(&s->pb, 5, s->qscale);
 414             }else{
 415                 put_bits(&s->pb, 1, 1); /* macroblock_type : macroblock_quant = 0 */
 416                 s->qscale -= s->dquant;
 417             }
 418             s->misc_bits+= get_bits_diff(s);
 419             s->i_count++;
 420         } else if (s->mb_intra) {
 421             if(s->dquant && cbp){
 422                 put_bits(&s->pb, 6, 0x01);
 423                 put_bits(&s->pb, 5, s->qscale);
 424             }else{
 425                 put_bits(&s->pb, 5, 0x03);
 426                 s->qscale -= s->dquant;
 427             }
 428             s->misc_bits+= get_bits_diff(s);
 429             s->i_count++;
 430             s->last_mv[0][0][0] =
 431             s->last_mv[0][0][1] = 0;
 432         } else if (s->pict_type == P_TYPE) {
 433                 if (cbp != 0) {
 434                     if (motion_x == 0 && motion_y == 0) {
 435                         if(s->dquant){
 436                             put_bits(&s->pb, 5, 1); /* macroblock_pattern & quant */
 437                             put_bits(&s->pb, 5, s->qscale);
 438                         }else{
 439                             put_bits(&s->pb, 2, 1); /* macroblock_pattern only */
 440                         }
 441                         s->misc_bits+= get_bits_diff(s);
 442                         put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
 443                     } else {
 444                         if(s->dquant){
 445                             put_bits(&s->pb, 5, 2); /* motion + cbp */
 446                             put_bits(&s->pb, 5, s->qscale);
 447                         }else{
 448                             put_bits(&s->pb, 1, 1); /* motion + cbp */
 449                         }
 450                         s->misc_bits+= get_bits_diff(s);
 451                         mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0], s->f_code);    // RAL: f_code parameter added
 452                         mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1], s->f_code);    // RAL: f_code parameter added
 453                         s->mv_bits+= get_bits_diff(s);
 454                         put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
 455                     }
 456                 } else {
 457                     put_bits(&s->pb, 3, 1); /* motion only */
 458                     mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0], s->f_code);    // RAL: f_code parameter added
 459                     mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1], s->f_code);    // RAL: f_code parameter added
 460                     s->qscale -= s->dquant;
 461                     s->mv_bits+= get_bits_diff(s);
 462                 }
 463                 s->f_count++;
 464         } else
 465             {    // RAL: All the following bloc added for B frames:
 466                 if (cbp != 0)
 467                     {    // With coded bloc pattern
 468                     if (s->mv_dir == (MV_DIR_FORWARD | MV_DIR_BACKWARD))
 469                         {    // Bi-directional motion
 470                         if (s->dquant)
 471                             {    // With QScale
 472                             put_bits(&s->pb, 5, 2);
 473                             put_bits(&s->pb, 5, s->qscale);
 474                             }
 475                         else    // Without QScale
 476                             put_bits(&s->pb, 2, 3);
 477                         s->misc_bits += get_bits_diff(s);
 478                         mpeg1_encode_motion(s, s->mv[0][0][0] - s->last_mv[0][0][0], s->f_code);
 479                         mpeg1_encode_motion(s, s->mv[0][0][1] - s->last_mv[0][0][1], s->f_code);
 480                         mpeg1_encode_motion(s, s->mv[1][0][0] - s->last_mv[1][0][0], s->b_code);
 481                         mpeg1_encode_motion(s, s->mv[1][0][1] - s->last_mv[1][0][1], s->b_code);
 482                         s->b_count++;
 483                         s->f_count++;
 484                         s->mv_bits += get_bits_diff(s);
 485                         put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
 486                         }
 487                     else if (s->mv_dir == MV_DIR_BACKWARD)
 488                         {    // Backward motion
 489                         if (s->dquant)
 490                             {    // With QScale
 491                             put_bits(&s->pb, 6, 2);
 492                             put_bits(&s->pb, 5, s->qscale);
 493                             }
 494                         else    // Without QScale
 495                             put_bits(&s->pb, 3, 3);
 496                         s->misc_bits += get_bits_diff(s);
 497                         mpeg1_encode_motion(s, motion_x - s->last_mv[1][0][0], s->b_code);
 498                         mpeg1_encode_motion(s, motion_y - s->last_mv[1][0][1], s->b_code);
 499                         s->b_count++;
 500                         s->mv_bits += get_bits_diff(s);
 501                         put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
 502                         }
 503                     else if (s->mv_dir == MV_DIR_FORWARD)
 504                         {    // Forward motion
 505                         if (s->dquant)
 506                             {    // With QScale
 507                             put_bits(&s->pb, 6, 3);
 508                             put_bits(&s->pb, 5, s->qscale);
 509                             }
 510                         else    // Without QScale
 511                             put_bits(&s->pb, 4, 3);
 512                         s->misc_bits += get_bits_diff(s);
 513                         mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0], s->f_code);
 514                         mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1], s->f_code);
 515                         s->f_count++;
 516                         s->mv_bits += get_bits_diff(s);
 517                         put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
 518                         }
 519                     }
 520                 else
 521                     {    // No coded bloc pattern
 522                     if (s->mv_dir == (MV_DIR_FORWARD | MV_DIR_BACKWARD))
 523                         {    // Bi-directional motion
 524                         put_bits(&s->pb, 2, 2); /* backward & forward motion */
 525                         mpeg1_encode_motion(s, s->mv[0][0][0] - s->last_mv[0][0][0], s->f_code);
 526                         mpeg1_encode_motion(s, s->mv[0][0][1] - s->last_mv[0][0][1], s->f_code);
 527                         mpeg1_encode_motion(s, s->mv[1][0][0] - s->last_mv[1][0][0], s->b_code);
 528                         mpeg1_encode_motion(s, s->mv[1][0][1] - s->last_mv[1][0][1], s->b_code);
 529                         s->b_count++;
 530                         s->f_count++;
 531                         }
 532                     else if (s->mv_dir == MV_DIR_BACKWARD)
 533                         {    // Backward motion
 534                         put_bits(&s->pb, 3, 2); /* backward motion only */
 535                         mpeg1_encode_motion(s, motion_x - s->last_mv[1][0][0], s->b_code);
 536                         mpeg1_encode_motion(s, motion_y - s->last_mv[1][0][1], s->b_code);
 537                         s->b_count++;
 538                         }
 539                     else if (s->mv_dir == MV_DIR_FORWARD)
 540                         {    // Forward motion
 541                         put_bits(&s->pb, 4, 2); /* forward motion only */
 542                         mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0], s->f_code);
 543                         mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1], s->f_code);
 544                         s->f_count++;
 545                         }
 546                     s->qscale -= s->dquant;
 547                     s->mv_bits += get_bits_diff(s);
 548                     }
 549             // End of bloc from RAL
 550             }
 551         for(i=0;i<6;i++) {
 552             if (cbp & (1 << (5 - i))) {
 553                 mpeg1_encode_block(s, block[i], i);
 554             }
 555         }
 556         s->mb_skip_run = 0;
 557         if(s->mb_intra)
 558             s->i_tex_bits+= get_bits_diff(s);
 559         else
 560             s->p_tex_bits+= get_bits_diff(s);
 561     }
 562
 563     // RAL: By this:
 564     if (s->mv_dir & MV_DIR_FORWARD)
 565         {
 566         s->last_mv[0][0][0]= s->mv[0][0][0];
 567         s->last_mv[0][0][1]= s->mv[0][0][1];
 568         }
 569     if (s->mv_dir & MV_DIR_BACKWARD)
 570         {
 571         s->last_mv[1][0][0]= s->mv[1][0][0];
 572         s->last_mv[1][0][1]= s->mv[1][0][1];
 573         }
 574 }
 575
 576 // RAL: Parameter added: f_or_b_code
 577 static void mpeg1_encode_motion(MpegEncContext *s, int val, int f_or_b_code)
 578 {
 579     int code, bit_size, l, m, bits, range, sign;
 580
 581     if (val == 0) {
 582         /* zero vector */
 583         code = 0;
 584         put_bits(&s->pb,
 585                  mbMotionVectorTable[0][1],
 586                  mbMotionVectorTable[0][0]);
 587     } else {
 588         bit_size = f_or_b_code - 1;
 589         range = 1 << bit_size;
 590         /* modulo encoding */
 591         l = 16 * range;
 592         m = 2 * l;
 593         if (val < -l) {
 594             val += m;
 595         } else if (val >= l) {
 596             val -= m;
 597         }
 598
 599         if (val >= 0) {
 600             val--;
 601             code = (val >> bit_size) + 1;
 602             bits = val & (range - 1);
 603             sign = 0;
 604         } else {
 605             val = -val;
 606             val--;
 607             code = (val >> bit_size) + 1;
 608             bits = val & (range - 1);
 609             sign = 1;
 610         }
 611
 612         assert(code > 0 && code <= 16);
 613
 614         put_bits(&s->pb,
 615                  mbMotionVectorTable[code][1],
 616                  mbMotionVectorTable[code][0]);
 617
 618         put_bits(&s->pb, 1, sign);
 619         if (bit_size > 0) {
 620             put_bits(&s->pb, bit_size, bits);
 621         }
 622     }
 623 }
 624
 625 void ff_mpeg1_encode_init(MpegEncContext *s)
 626 {
 627     static int done=0;
 628
 629     common_init(s);
 630
 631     if(!done){
 632         int f_code;
 633         int mv;
 634         int i;
 635
 636         done=1;
 637         init_rl(&rl_mpeg1);
 638
 639         for(i=0; i<64; i++)
 640         {
 641                 mpeg1_max_level[0][i]= rl_mpeg1.max_level[0][i];
 642                 mpeg1_index_run[0][i]= rl_mpeg1.index_run[0][i];
 643         }
 644
 645         init_uni_ac_vlc(&rl_mpeg1, uni_mpeg1_ac_vlc_bits, uni_mpeg1_ac_vlc_len);
 646
 647         /* build unified dc encoding tables */
 648         for(i=-255; i<256; i++)
 649         {
 650                 int adiff, index;
 651                 int bits, code;
 652                 int diff=i;
 653
 654                 adiff = ABS(diff);
 655                 if(diff<0) diff--;
 656                 index = vlc_dc_table[adiff];
 657
 658                 bits= vlc_dc_lum_bits[index] + index;
 659                 code= (vlc_dc_lum_code[index]<<index) + (diff & ((1 << index) - 1));
 660                 mpeg1_lum_dc_uni[i+255]= bits + (code<<8);
 661
 662                 bits= vlc_dc_chroma_bits[index] + index;
 663                 code= (vlc_dc_chroma_code[index]<<index) + (diff & ((1 << index) - 1));
 664                 mpeg1_chr_dc_uni[i+255]= bits + (code<<8);
 665         }
 666
 667         mv_penalty= av_mallocz( sizeof(uint8_t)*(MAX_FCODE+1)*(2*MAX_MV+1) );
 668
 669         for(f_code=1; f_code<=MAX_FCODE; f_code++){
 670             for(mv=-MAX_MV; mv<=MAX_MV; mv++){
 671                 int len;
 672
 673                 if(mv==0) len= mbMotionVectorTable[0][1];
 674                 else{
 675                     int val, bit_size, range, code;
 676
 677                     bit_size = s->f_code - 1;
 678                     range = 1 << bit_size;
 679
 680                     val=mv;
 681                     if (val < 0)
 682                         val = -val;
 683                     val--;
 684                     code = (val >> bit_size) + 1;
 685                     if(code<17){
 686                         len= mbMotionVectorTable[code][1] + 1 + bit_size;
 687                     }else{
 688                         len= mbMotionVectorTable[16][1] + 2 + bit_size;
 689                     }
 690                 }
 691
 692                 mv_penalty[f_code][mv+MAX_MV]= len;
 693             }
 694         }
 695
 696
 697         for(f_code=MAX_FCODE; f_code>0; f_code--){
 698             for(mv=-(8<<f_code); mv<(8<<f_code); mv++){
 699                 fcode_tab[mv+MAX_MV]= f_code;
 700             }
 701         }
 702     }
 703     s->me.mv_penalty= mv_penalty;
 704     s->fcode_tab= fcode_tab;
 705     s->min_qcoeff=-255;
 706     s->max_qcoeff= 255;
 707     s->intra_ac_vlc_length=
 708     s->inter_ac_vlc_length= uni_mpeg1_ac_vlc_len;
 709 }
 710
 711 static inline void encode_dc(MpegEncContext *s, int diff, int component)
 712 {
 713     if (component == 0) {
 714         put_bits(
 715             &s->pb,
 716             mpeg1_lum_dc_uni[diff+255]&0xFF,
 717             mpeg1_lum_dc_uni[diff+255]>>8);
 718     } else {
 719         put_bits(
 720             &s->pb,
 721             mpeg1_chr_dc_uni[diff+255]&0xFF,
 722             mpeg1_chr_dc_uni[diff+255]>>8);
 723     }
 724 }
 725
 726 static void mpeg1_encode_block(MpegEncContext *s,
 727                                DCTELEM *block,
 728                                int n)
 729 {
 730     int alevel, level, last_non_zero, dc, diff, i, j, run, last_index, sign;
 731     int code, component;
 732 //    RLTable *rl = &rl_mpeg1;
 733
 734     last_index = s->block_last_index[n];
 735
 736     /* DC coef */
 737     if (s->mb_intra) {
 738         component = (n <= 3 ? 0 : n - 4 + 1);
 739         dc = block[0]; /* overflow is impossible */
 740         diff = dc - s->last_dc[component];
 741         encode_dc(s, diff, component);
 742         s->last_dc[component] = dc;
 743         i = 1;
 744     } else {
 745         /* encode the first coefficient : needs to be done here because
 746            it is handled slightly differently */
 747         level = block[0];
 748         if (abs(level) == 1) {
 749                 code = ((uint32_t)level >> 31); /* the sign bit */
 750                 put_bits(&s->pb, 2, code | 0x02);
 751                 i = 1;
 752         } else {
 753             i = 0;
 754             last_non_zero = -1;
 755             goto next_coef;
 756         }
 757     }
 758
 759     /* now quantify & encode AC coefs */
 760     last_non_zero = i - 1;
 761
 762     for(;i<=last_index;i++) {
 763         j = s->intra_scantable.permutated[i];
 764         level = block[j];
 765     next_coef:
 766 #if 0
 767         if (level != 0)
 768             dprintf("level[%d]=%d\n", i, level);
 769 #endif
 770         /* encode using VLC */
 771         if (level != 0) {
 772             run = i - last_non_zero - 1;
 773
 774             alevel= level;
 775             MASK_ABS(sign, alevel)
 776             sign&=1;
 777
 778 //            code = get_rl_index(rl, 0, run, alevel);
 779             if (alevel <= mpeg1_max_level[0][run]){
 780                 code= mpeg1_index_run[0][run] + alevel - 1;
 781                 /* store the vlc & sign at once */
 782                 put_bits(&s->pb, mpeg1_vlc[code][1]+1, (mpeg1_vlc[code][0]<<1) + sign);
 783             } else {
 784                 /* escape seems to be pretty rare <5% so i dont optimize it */
 785                 put_bits(&s->pb, mpeg1_vlc[111/*rl->n*/][1], mpeg1_vlc[111/*rl->n*/][0]);
 786                 /* escape: only clip in this case */
 787                 put_bits(&s->pb, 6, run);
 788                 if (alevel < 128) {
 789                     put_bits(&s->pb, 8, level & 0xff);
 790                 } else {
 791                     if (level < 0) {
 792                         put_bits(&s->pb, 16, 0x8001 + level + 255);
 793                     } else {
 794                         put_bits(&s->pb, 16, level & 0xffff);
 795                     }
 796                 }
 797             }
 798             last_non_zero = i;
 799         }
 800     }
 801     /* end of block */
 802     put_bits(&s->pb, 2, 0x2);
 803 }
 804 #endif //CONFIG_ENCODERS
 805
 806 /******************************************/
 807 /* decoding */
 808
 809 static VLC dc_lum_vlc;
 810 static VLC dc_chroma_vlc;
 811 static VLC mv_vlc;
 812 static VLC mbincr_vlc;
 813 static VLC mb_ptype_vlc;
 814 static VLC mb_btype_vlc;
 815 static VLC mb_pat_vlc;
 816
 817 static void init_vlcs(MpegEncContext *s)
 818 {
 819     static int done = 0;
 820
 821     if (!done) {
 822         done = 1;
 823
 824         init_vlc(&dc_lum_vlc, DC_VLC_BITS, 12,
 825                  vlc_dc_lum_bits, 1, 1,
 826                  vlc_dc_lum_code, 2, 2);
 827         init_vlc(&dc_chroma_vlc,  DC_VLC_BITS, 12,
 828                  vlc_dc_chroma_bits, 1, 1,
 829                  vlc_dc_chroma_code, 2, 2);
 830         init_vlc(&mv_vlc, MV_VLC_BITS, 17,
 831                  &mbMotionVectorTable[0][1], 2, 1,
 832                  &mbMotionVectorTable[0][0], 2, 1);
 833         init_vlc(&mbincr_vlc, MBINCR_VLC_BITS, 36,
 834                  &mbAddrIncrTable[0][1], 2, 1,
 835                  &mbAddrIncrTable[0][0], 2, 1);
 836         init_vlc(&mb_pat_vlc, MB_PAT_VLC_BITS, 63,
 837                  &mbPatTable[0][1], 2, 1,
 838                  &mbPatTable[0][0], 2, 1);
 839
 840         init_vlc(&mb_ptype_vlc, MB_PTYPE_VLC_BITS, 7,
 841                  &table_mb_ptype[0][1], 2, 1,
 842                  &table_mb_ptype[0][0], 2, 1);
 843         init_vlc(&mb_btype_vlc, MB_BTYPE_VLC_BITS, 11,
 844                  &table_mb_btype[0][1], 2, 1,
 845                  &table_mb_btype[0][0], 2, 1);
 846         init_rl(&rl_mpeg1);
 847         init_rl(&rl_mpeg2);
 848
 849         init_2d_vlc_rl(&rl_mpeg1);
 850         init_2d_vlc_rl(&rl_mpeg2);
 851     }
 852 }
 853
 854 static inline int get_dmv(MpegEncContext *s)
 855 {
 856     if(get_bits1(&s->gb))
 857         return 1 - (get_bits1(&s->gb) << 1);
 858     else
 859         return 0;
 860 }
 861
 862 static inline int get_qscale(MpegEncContext *s)
 863 {
 864     int qscale = get_bits(&s->gb, 5);
 865     if (s->mpeg2) {
 866         if (s->q_scale_type) {
 867             return non_linear_qscale[qscale];
 868         } else {
 869             return qscale << 1;
 870         }
 871     }
 872     return qscale;
 873 }
 874
 875 /* motion type (for mpeg2) */
 876 #define MT_FIELD 1
 877 #define MT_FRAME 2
 878 #define MT_16X8  2
 879 #define MT_DMV   3
 880
 881 static int mpeg_decode_mb(MpegEncContext *s,
 882                           DCTELEM block[6][64])
 883 {
 884     int i, j, k, cbp, val, mb_type, motion_type;
 885
 886     dprintf("decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
 887
 888     assert(s->mb_skiped==0);
 889
 890     if (s->mb_skip_run-- != 0) {
 891         if(s->pict_type == I_TYPE){
 892             fprintf(stderr, "skiped MB in I frame at %d %d\n", s->mb_x, s->mb_y);
 893             return -1;
 894         }
 895
 896         /* skip mb */
 897         s->mb_intra = 0;
 898         for(i=0;i<6;i++)
 899             s->block_last_index[i] = -1;
 900         s->mv_type = MV_TYPE_16X16;
 901         if (s->pict_type == P_TYPE) {
 902             /* if P type, zero motion vector is implied */
 903             s->mv_dir = MV_DIR_FORWARD;
 904             s->mv[0][0][0] = s->mv[0][0][1] = 0;
 905             s->last_mv[0][0][0] = s->last_mv[0][0][1] = 0;
 906             s->last_mv[0][1][0] = s->last_mv[0][1][1] = 0;
 907             s->mb_skiped = 1;
 908             s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]= MB_TYPE_SKIP | MB_TYPE_L0 | MB_TYPE_16x16;
 909         } else {
 910             /* if B type, reuse previous vectors and directions */
 911             s->mv[0][0][0] = s->last_mv[0][0][0];
 912             s->mv[0][0][1] = s->last_mv[0][0][1];
 913             s->mv[1][0][0] = s->last_mv[1][0][0];
 914             s->mv[1][0][1] = s->last_mv[1][0][1];
 915
 916             s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]=
 917                 s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride - 1] | MB_TYPE_SKIP;
 918 //            assert(s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride - 1]&(MB_TYPE_16x16|MB_TYPE_16x8));
 919
 920             if((s->mv[0][0][0]|s->mv[0][0][1]|s->mv[1][0][0]|s->mv[1][0][1])==0)
 921                 s->mb_skiped = 1;
 922         }
 923
 924         return 0;
 925     }
 926
 927     switch(s->pict_type) {
 928     default:
 929     case I_TYPE:
 930         if (get_bits1(&s->gb) == 0) {
 931             if (get_bits1(&s->gb) == 0)
 932                 return -1;
 933             mb_type = MB_TYPE_QUANT | MB_TYPE_INTRA;
 934         } else {
 935             mb_type = MB_TYPE_INTRA;
 936         }
 937         break;
 938     case P_TYPE:
 939         mb_type = get_vlc2(&s->gb, mb_ptype_vlc.table, MB_PTYPE_VLC_BITS, 1);
 940         if (mb_type < 0){
 941             fprintf(stderr, "invalid mb type in P Frame at %d %d\n", s->mb_x, s->mb_y);
 942             return -1;
 943         }
 944         mb_type = ptype2mb_type[ mb_type ];
 945         break;
 946     case B_TYPE:
 947         mb_type = get_vlc2(&s->gb, mb_btype_vlc.table, MB_BTYPE_VLC_BITS, 1);
 948         if (mb_type < 0){
 949             fprintf(stderr, "invalid mb type in B Frame at %d %d\n", s->mb_x, s->mb_y);
 950             return -1;
 951         }
 952         mb_type = btype2mb_type[ mb_type ];
 953         break;
 954     }
 955     dprintf("mb_type=%x\n", mb_type);
 956 //    motion_type = 0; /* avoid warning */
 957     if (IS_INTRA(mb_type)) {
 958         /* compute dct type */
 959         if (s->picture_structure == PICT_FRAME && //FIXME add a interlaced_dct coded var?
 960             !s->frame_pred_frame_dct) {
 961             s->interlaced_dct = get_bits1(&s->gb);
 962         }
 963
 964         if (IS_QUANT(mb_type))
 965             s->qscale = get_qscale(s);
 966
 967         if (s->concealment_motion_vectors) {
 968             /* just parse them */
 969             if (s->picture_structure != PICT_FRAME)
 970                 skip_bits1(&s->gb); /* field select */
 971
 972             s->mv[0][0][0]= s->last_mv[0][0][0]= s->last_mv[0][1][0] =
 973                 mpeg_decode_motion(s, s->mpeg_f_code[0][0], s->last_mv[0][0][0]);
 974             s->mv[0][0][1]= s->last_mv[0][0][1]= s->last_mv[0][1][1] =
 975                 mpeg_decode_motion(s, s->mpeg_f_code[0][1], s->last_mv[0][0][1]);
 976
 977             skip_bits1(&s->gb); /* marker */
 978         }else
 979             memset(s->last_mv, 0, sizeof(s->last_mv)); /* reset mv prediction */
 980         s->mb_intra = 1;
 981
 982         if (s->mpeg2) {
 983             for(i=0;i<6;i++) {
 984                 if (mpeg2_decode_block_intra(s, block[i], i) < 0)
 985                     return -1;
 986             }
 987         } else {
 988             for(i=0;i<6;i++) {
 989                 if (mpeg1_decode_block_intra(s, block[i], i) < 0)
 990                     return -1;
 991             }
 992         }
 993     } else {
 994         if (mb_type & MB_TYPE_ZERO_MV){
 995             assert(mb_type & MB_TYPE_PAT);
 996
 997             /* compute dct type */
 998             if (s->picture_structure == PICT_FRAME && //FIXME add a interlaced_dct coded var?
 999                 !s->frame_pred_frame_dct) {
1000                 s->interlaced_dct = get_bits1(&s->gb);
1001             }
1002
1003             if (IS_QUANT(mb_type))
1004                 s->qscale = get_qscale(s);
1005
1006             s->mv_dir = MV_DIR_FORWARD;
1007             s->mv_type = MV_TYPE_16X16;
1008             s->last_mv[0][0][0] = 0;
1009             s->last_mv[0][0][1] = 0;
1010             s->last_mv[0][1][0] = 0;
1011             s->last_mv[0][1][1] = 0;
1012             s->mv[0][0][0] = 0;
1013             s->mv[0][0][1] = 0;
1014         }else{
1015             assert(mb_type & MB_TYPE_L0L1);
1016 //FIXME decide if MBs in field pictures are MB_TYPE_INTERLACED
1017             /* get additionnal motion vector type */
1018             if (s->frame_pred_frame_dct)
1019                 motion_type = MT_FRAME;
1020             else{
1021                 motion_type = get_bits(&s->gb, 2);
1022             }
1023
1024             /* compute dct type */
1025             if (s->picture_structure == PICT_FRAME && //FIXME add a interlaced_dct coded var?
1026                 !s->frame_pred_frame_dct && IS_PAT(mb_type)) {
1027                 s->interlaced_dct = get_bits1(&s->gb);
1028             }
1029
1030             if (IS_QUANT(mb_type))
1031                 s->qscale = get_qscale(s);
1032
1033             /* motion vectors */
1034             s->mv_dir = 0;
1035             for(i=0;i<2;i++) {
1036                 if (USES_LIST(mb_type, i)) {
1037                     s->mv_dir |= (MV_DIR_FORWARD >> i);
1038                     dprintf("motion_type=%d\n", motion_type);
1039                     switch(motion_type) {
1040                     case MT_FRAME: /* or MT_16X8 */
1041                         if (s->picture_structure == PICT_FRAME) {
1042                             /* MT_FRAME */
1043                             mb_type |= MB_TYPE_16x16;
1044                             s->mv_type = MV_TYPE_16X16;
1045                             s->mv[i][0][0]= s->last_mv[i][0][0]= s->last_mv[i][1][0] =
1046                                 mpeg_decode_motion(s, s->mpeg_f_code[i][0], s->last_mv[i][0][0]);
1047                             s->mv[i][0][1]= s->last_mv[i][0][1]= s->last_mv[i][1][1] =
1048                                 mpeg_decode_motion(s, s->mpeg_f_code[i][1], s->last_mv[i][0][1]);
1049                             /* full_pel: only for mpeg1 */
1050                             if (s->full_pel[i]){
1051                                 s->mv[i][0][0] <<= 1;
1052                                 s->mv[i][0][1] <<= 1;
1053                             }
1054                         } else {
1055                             /* MT_16X8 */
1056                             mb_type |= MB_TYPE_16x8;
1057                             s->mv_type = MV_TYPE_16X8;
1058                             for(j=0;j<2;j++) {
1059                                 s->field_select[i][j] = get_bits1(&s->gb);
1060                                 for(k=0;k<2;k++) {
1061                                     val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
1062                                                              s->last_mv[i][j][k]);
1063                                     s->last_mv[i][j][k] = val;
1064                                     s->mv[i][j][k] = val;
1065                                 }
1066                             }
1067                         }
1068                         break;
1069                     case MT_FIELD:
1070                         s->mv_type = MV_TYPE_FIELD;
1071                         if (s->picture_structure == PICT_FRAME) {
1072                             mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
1073                             for(j=0;j<2;j++) {
1074                                 s->field_select[i][j] = get_bits1(&s->gb);
1075                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
1076                                                          s->last_mv[i][j][0]);
1077                                 s->last_mv[i][j][0] = val;
1078                                 s->mv[i][j][0] = val;
1079                                 dprintf("fmx=%d\n", val);
1080                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
1081                                                          s->last_mv[i][j][1] >> 1);
1082                                 s->last_mv[i][j][1] = val << 1;
1083                                 s->mv[i][j][1] = val;
1084                                 dprintf("fmy=%d\n", val);
1085                             }
1086                         } else {
1087                             mb_type |= MB_TYPE_16x16;
1088                             s->field_select[i][0] = get_bits1(&s->gb);
1089                             for(k=0;k<2;k++) {
1090                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
1091                                                          s->last_mv[i][0][k]);
1092                                 s->last_mv[i][0][k] = val;
1093                                 s->last_mv[i][1][k] = val;
1094                                 s->mv[i][0][k] = val;
1095                             }
1096                         }
1097                         break;
1098                     case MT_DMV:
1099                         {
1100                             int dmx, dmy, mx, my, m;
1101
1102                             mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
1103                                                     s->last_mv[i][0][0]);
1104                             s->last_mv[i][0][0] = mx;
1105                             s->last_mv[i][1][0] = mx;
1106                             dmx = get_dmv(s);
1107                             my = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
1108                                                     s->last_mv[i][0][1] >> 1);
1109                             dmy = get_dmv(s);
1110                             s->mv_type = MV_TYPE_DMV;
1111
1112
1113                             s->last_mv[i][0][1] = my<<1;
1114                             s->last_mv[i][1][1] = my<<1;
1115
1116                             s->mv[i][0][0] = mx;
1117                             s->mv[i][0][1] = my;
1118                             s->mv[i][1][0] = mx;//not used
1119                             s->mv[i][1][1] = my;//not used
1120
1121                             if (s->picture_structure == PICT_FRAME) {
1122                                 mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
1123
1124                                 //m = 1 + 2 * s->top_field_first;
1125                                 m = s->top_field_first ? 1 : 3;
1126
1127                                 /* top -> top pred */
1128                                 s->mv[i][2][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
1129                                 s->mv[i][2][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
1130                                 m = 4 - m;
1131                                 s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
1132                                 s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
1133                             } else {
1134                                 mb_type |= MB_TYPE_16x16;
1135
1136                                 s->mv[i][2][0] = ((mx + (mx > 0)) >> 1) + dmx;
1137                                 s->mv[i][2][1] = ((my + (my > 0)) >> 1) + dmy;
1138                                 if(s->picture_structure == PICT_TOP_FIELD)
1139                                     s->mv[i][2][1]--;
1140                                 else
1141                                     s->mv[i][2][1]++;
1142                             }
1143                         }
1144                         break;
1145                     }
1146                 }
1147             }
1148         }
1149
1150         s->mb_intra = 0;
1151
1152         if (IS_PAT(mb_type)) {
1153             cbp = get_vlc2(&s->gb, mb_pat_vlc.table, MB_PAT_VLC_BITS, 1);
1154             if (cbp < 0){
1155                 fprintf(stderr, "invalid cbp at %d %d\n", s->mb_x, s->mb_y);
1156                 return -1;
1157             }
1158             cbp++;
1159
1160             if (s->mpeg2) {
1161                 for(i=0;i<6;i++) {
1162                     if (cbp & 32) {
1163                         if (mpeg2_decode_block_non_intra(s, block[i], i) < 0)
1164                             return -1;
1165                     } else {
1166                         s->block_last_index[i] = -1;
1167                     }
1168                     cbp+=cbp;
1169                 }
1170             } else {
1171                 for(i=0;i<6;i++) {
1172                     if (cbp & 32) {
1173                         if (mpeg1_decode_block_inter(s, block[i], i) < 0)
1174                             return -1;
1175                     } else {
1176                         s->block_last_index[i] = -1;
1177                     }
1178                     cbp+=cbp;
1179                 }
1180             }
1181         }else{
1182             for(i=0;i<6;i++)
1183                 s->block_last_index[i] = -1;
1184         }
1185     }
1186
1187     s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]= mb_type;
1188
1189     return 0;
1190 }
1191
1192 /* as h263, but only 17 codes */
1193 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
1194 {
1195     int code, sign, val, l, shift;
1196
1197     code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2);
1198     if (code == 0) {
1199         return pred;
1200     }
1201     if (code < 0) {
1202         return 0xffff;
1203     }
1204
1205     sign = get_bits1(&s->gb);
1206     shift = fcode - 1;
1207     val = code;
1208     if (shift) {
1209         val = (val - 1) << shift;
1210         val |= get_bits(&s->gb, shift);
1211         val++;
1212     }
1213     if (sign)
1214         val = -val;
1215     val += pred;
1216
1217     /* modulo decoding */
1218     l = 1 << (shift+4);
1219     val = ((val + l)&(l*2-1)) - l;
1220     return val;
1221 }
1222
1223 static inline int decode_dc(MpegEncContext *s, int component)
1224 {
1225     int code, diff;
1226
1227     if (component == 0) {
1228         code = get_vlc2(&s->gb, dc_lum_vlc.table, DC_VLC_BITS, 2);
1229     } else {
1230         code = get_vlc2(&s->gb, dc_chroma_vlc.table, DC_VLC_BITS, 2);
1231     }
1232     if (code < 0){
1233         fprintf(stderr, "invalid dc code at %d %d\n", s->mb_x, s->mb_y);
1234         return 0xffff;
1235     }
1236     if (code == 0) {
1237         diff = 0;
1238     } else {
1239         diff = get_xbits(&s->gb, code);
1240     }
1241     return diff;
1242 }
1243
1244 static inline int mpeg1_decode_block_intra(MpegEncContext *s,
1245                                DCTELEM *block,
1246                                int n)
1247 {
1248     int level, dc, diff, i, j, run;
1249     int component;
1250     RLTable *rl = &rl_mpeg1;
1251     uint8_t * const scantable= s->intra_scantable.permutated;
1252     const uint16_t *quant_matrix= s->intra_matrix;
1253     const int qscale= s->qscale;
1254
1255     /* DC coef */
1256     component = (n <= 3 ? 0 : n - 4 + 1);
1257     diff = decode_dc(s, component);
1258     if (diff >= 0xffff)
1259         return -1;
1260     dc = s->last_dc[component];
1261     dc += diff;
1262     s->last_dc[component] = dc;
1263     block[0] = dc<<3;
1264     dprintf("dc=%d diff=%d\n", dc, diff);
1265     i = 0;
1266     {
1267         OPEN_READER(re, &s->gb);
1268         /* now quantify & encode AC coefs */
1269         for(;;) {
1270             UPDATE_CACHE(re, &s->gb);
1271             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2);
1272
1273             if(level == 127){
1274                 break;
1275             } else if(level != 0) {
1276                 i += run;
1277                 j = scantable[i];
1278                 level= (level*qscale*quant_matrix[j])>>3;
1279                 level= (level-1)|1;
1280                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1281                 LAST_SKIP_BITS(re, &s->gb, 1);
1282             } else {
1283                 /* escape */
1284                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1285                 UPDATE_CACHE(re, &s->gb);
1286                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
1287                 if (level == -128) {
1288                     level = SHOW_UBITS(re, &s->gb, 8) - 256; LAST_SKIP_BITS(re, &s->gb, 8);
1289                 } else if (level == 0) {
1290                     level = SHOW_UBITS(re, &s->gb, 8)      ; LAST_SKIP_BITS(re, &s->gb, 8);
1291                 }
1292                 i += run;
1293                 j = scantable[i];
1294                 if(level<0){
1295                     level= -level;
1296                     level= (level*qscale*quant_matrix[j])>>3;
1297                     level= (level-1)|1;
1298                     level= -level;
1299                 }else{
1300                     level= (level*qscale*quant_matrix[j])>>3;
1301                     level= (level-1)|1;
1302                 }
1303             }
1304             if (i > 63){
1305                 fprintf(stderr, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1306                 return -1;
1307             }
1308
1309             block[j] = level;
1310         }
1311         CLOSE_READER(re, &s->gb);
1312     }
1313     s->block_last_index[n] = i;
1314    return 0;
1315 }
1316
1317 static inline int mpeg1_decode_block_inter(MpegEncContext *s,
1318                                DCTELEM *block,
1319                                int n)
1320 {
1321     int level, i, j, run;
1322     RLTable *rl = &rl_mpeg1;
1323     uint8_t * const scantable= s->intra_scantable.permutated;
1324     const uint16_t *quant_matrix= s->inter_matrix;
1325     const int qscale= s->qscale;
1326
1327     {
1328         int v;
1329         OPEN_READER(re, &s->gb);
1330         i = -1;
1331         /* special case for the first coef. no need to add a second vlc table */
1332         UPDATE_CACHE(re, &s->gb);
1333         v= SHOW_UBITS(re, &s->gb, 2);
1334         if (v & 2) {
1335             LAST_SKIP_BITS(re, &s->gb, 2);
1336             level= (3*qscale*quant_matrix[0])>>4;
1337             level= (level-1)|1;
1338             if(v&1)
1339                 level= -level;
1340             block[0] = level;
1341             i++;
1342         }
1343
1344         /* now quantify & encode AC coefs */
1345         for(;;) {
1346             UPDATE_CACHE(re, &s->gb);
1347             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2);
1348
1349             if(level == 127){
1350                 break;
1351             } else if(level != 0) {
1352                 i += run;
1353                 j = scantable[i];
1354                 level= ((level*2+1)*qscale*quant_matrix[j])>>4;
1355                 level= (level-1)|1;
1356                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1357                 LAST_SKIP_BITS(re, &s->gb, 1);
1358             } else {
1359                 /* escape */
1360                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1361                 UPDATE_CACHE(re, &s->gb);
1362                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
1363                 if (level == -128) {
1364                     level = SHOW_UBITS(re, &s->gb, 8) - 256; LAST_SKIP_BITS(re, &s->gb, 8);
1365                 } else if (level == 0) {
1366                     level = SHOW_UBITS(re, &s->gb, 8)      ; LAST_SKIP_BITS(re, &s->gb, 8);
1367                 }
1368                 i += run;
1369                 j = scantable[i];
1370                 if(level<0){
1371                     level= -level;
1372                     level= ((level*2+1)*qscale*quant_matrix[j])>>4;
1373                     level= (level-1)|1;
1374                     level= -level;
1375                 }else{
1376                     level= ((level*2+1)*qscale*quant_matrix[j])>>4;
1377                     level= (level-1)|1;
1378                 }
1379             }
1380             if (i > 63){
1381                 fprintf(stderr, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1382                 return -1;
1383             }
1384
1385             block[j] = level;
1386         }
1387         CLOSE_READER(re, &s->gb);
1388     }
1389     s->block_last_index[n] = i;
1390     return 0;
1391 }
1392
1393 /* Also does unquantization here, since I will never support mpeg2
1394    encoding */
1395 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
1396                                DCTELEM *block,
1397                                int n)
1398 {
1399     int level, i, j, run;
1400     RLTable *rl = &rl_mpeg1;
1401     uint8_t * const scantable= s->intra_scantable.permutated;
1402     const uint16_t *quant_matrix;
1403     const int qscale= s->qscale;
1404     int mismatch;
1405
1406     mismatch = 1;
1407
1408     {
1409         int v;
1410         OPEN_READER(re, &s->gb);
1411         i = -1;
1412         if (n < 4)
1413             quant_matrix = s->inter_matrix;
1414         else
1415             quant_matrix = s->chroma_inter_matrix;
1416
1417         /* special case for the first coef. no need to add a second vlc table */
1418         UPDATE_CACHE(re, &s->gb);
1419         v= SHOW_UBITS(re, &s->gb, 2);
1420         if (v & 2) {
1421             LAST_SKIP_BITS(re, &s->gb, 2);
1422             level= (3*qscale*quant_matrix[0])>>5;
1423             if(v&1)
1424                 level= -level;
1425             block[0] = level;
1426             mismatch ^= level;
1427             i++;
1428         }
1429
1430         /* now quantify & encode AC coefs */
1431         for(;;) {
1432             UPDATE_CACHE(re, &s->gb);
1433             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2);
1434
1435             if(level == 127){
1436                 break;
1437             } else if(level != 0) {
1438                 i += run;
1439                 j = scantable[i];
1440                 level= ((level*2+1)*qscale*quant_matrix[j])>>5;
1441                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1442                 LAST_SKIP_BITS(re, &s->gb, 1);
1443             } else {
1444                 /* escape */
1445                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1446                 UPDATE_CACHE(re, &s->gb);
1447                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
1448
1449                 i += run;
1450                 j = scantable[i];
1451                 if(level<0){
1452                     level= ((-level*2+1)*qscale*quant_matrix[j])>>5;
1453                     level= -level;
1454                 }else{
1455                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
1456                 }
1457             }
1458             if (i > 63){
1459                 fprintf(stderr, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1460                 return -1;
1461             }
1462
1463             mismatch ^= level;
1464             block[j] = level;
1465         }
1466         CLOSE_READER(re, &s->gb);
1467     }
1468     block[63] ^= (mismatch & 1);
1469
1470     s->block_last_index[n] = i;
1471     return 0;
1472 }
1473
1474 static inline int mpeg2_decode_block_intra(MpegEncContext *s,
1475                                DCTELEM *block,
1476                                int n)
1477 {
1478     int level, dc, diff, i, j, run;
1479     int component;
1480     RLTable *rl;
1481     uint8_t * const scantable= s->intra_scantable.permutated;
1482     const uint16_t *quant_matrix;
1483     const int qscale= s->qscale;
1484     int mismatch;
1485
1486     /* DC coef */
1487     if (n < 4){
1488         quant_matrix = s->intra_matrix;
1489         component = 0;
1490     }else{
1491         quant_matrix = s->chroma_intra_matrix;
1492         component = n - 3;
1493     }
1494     diff = decode_dc(s, component);
1495     if (diff >= 0xffff)
1496         return -1;
1497     dc = s->last_dc[component];
1498     dc += diff;
1499     s->last_dc[component] = dc;
1500     block[0] = dc << (3 - s->intra_dc_precision);
1501     dprintf("dc=%d\n", block[0]);
1502     mismatch = block[0] ^ 1;
1503     i = 0;
1504     if (s->intra_vlc_format)
1505         rl = &rl_mpeg2;
1506     else
1507         rl = &rl_mpeg1;
1508
1509     {
1510         OPEN_READER(re, &s->gb);
1511         /* now quantify & encode AC coefs */
1512         for(;;) {
1513             UPDATE_CACHE(re, &s->gb);
1514             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2);
1515
1516             if(level == 127){
1517                 break;
1518             } else if(level != 0) {
1519                 i += run;
1520                 j = scantable[i];
1521                 level= (level*qscale*quant_matrix[j])>>4;
1522                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1523                 LAST_SKIP_BITS(re, &s->gb, 1);
1524             } else {
1525                 /* escape */
1526                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1527                 UPDATE_CACHE(re, &s->gb);
1528                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
1529                 i += run;
1530                 j = scantable[i];
1531                 if(level<0){
1532                     level= (-level*qscale*quant_matrix[j])>>4;
1533                     level= -level;
1534                 }else{
1535                     level= (level*qscale*quant_matrix[j])>>4;
1536                 }
1537             }
1538             if (i > 63){
1539                 fprintf(stderr, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1540                 return -1;
1541             }
1542
1543             mismatch^= level;
1544             block[j] = level;
1545         }
1546         CLOSE_READER(re, &s->gb);
1547     }
1548     block[63]^= mismatch&1;
1549
1550     s->block_last_index[n] = i;
1551     return 0;
1552 }
1553
1554 typedef struct Mpeg1Context {
1555     MpegEncContext mpeg_enc_ctx;
1556     int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
1557     int repeat_field; /* true if we must repeat the field */
1558 } Mpeg1Context;
1559
1560 static int mpeg_decode_init(AVCodecContext *avctx)
1561 {
1562     Mpeg1Context *s = avctx->priv_data;
1563
1564     s->mpeg_enc_ctx.flags= avctx->flags;
1565     common_init(&s->mpeg_enc_ctx);
1566     init_vlcs(&s->mpeg_enc_ctx);
1567
1568     s->mpeg_enc_ctx_allocated = 0;
1569     s->mpeg_enc_ctx.picture_number = 0;
1570     s->repeat_field = 0;
1571     s->mpeg_enc_ctx.codec_id= avctx->codec->id;
1572     return 0;
1573 }
1574
1575 /* return the 8 bit start code value and update the search
1576    state. Return -1 if no start code found */
1577 static int find_start_code(uint8_t **pbuf_ptr, uint8_t *buf_end)
1578 {
1579     uint8_t *buf_ptr;
1580     unsigned int state=0xFFFFFFFF, v;
1581     int val;
1582
1583     buf_ptr = *pbuf_ptr;
1584     while (buf_ptr < buf_end) {
1585         v = *buf_ptr++;
1586         if (state == 0x000001) {
1587             state = ((state << 8) | v) & 0xffffff;
1588             val = state;
1589             goto found;
1590         }
1591         state = ((state << 8) | v) & 0xffffff;
1592     }
1593     val = -1;
1594  found:
1595     *pbuf_ptr = buf_ptr;
1596     return val;
1597 }
1598
1599 static int mpeg1_decode_picture(AVCodecContext *avctx,
1600                                 uint8_t *buf, int buf_size)
1601 {
1602     Mpeg1Context *s1 = avctx->priv_data;
1603     MpegEncContext *s = &s1->mpeg_enc_ctx;
1604     int ref, f_code;
1605
1606     init_get_bits(&s->gb, buf, buf_size*8);
1607
1608     ref = get_bits(&s->gb, 10); /* temporal ref */
1609     s->pict_type = get_bits(&s->gb, 3);
1610     dprintf("pict_type=%d number=%d\n", s->pict_type, s->picture_number);
1611
1612     skip_bits(&s->gb, 16);
1613     if (s->pict_type == P_TYPE || s->pict_type == B_TYPE) {
1614         s->full_pel[0] = 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[0][0] = f_code;
1619         s->mpeg_f_code[0][1] = f_code;
1620     }
1621     if (s->pict_type == B_TYPE) {
1622         s->full_pel[1] = get_bits1(&s->gb);
1623         f_code = get_bits(&s->gb, 3);
1624         if (f_code == 0)
1625             return -1;
1626         s->mpeg_f_code[1][0] = f_code;
1627         s->mpeg_f_code[1][1] = f_code;
1628     }
1629     s->current_picture.pict_type= s->pict_type;
1630     s->current_picture.key_frame= s->pict_type == I_TYPE;
1631
1632     s->y_dc_scale = 8;
1633     s->c_dc_scale = 8;
1634     s->first_slice = 1;
1635     return 0;
1636 }
1637
1638 static void mpeg_decode_sequence_extension(MpegEncContext *s)
1639 {
1640     int horiz_size_ext, vert_size_ext;
1641     int bit_rate_ext, vbv_buf_ext;
1642     int frame_rate_ext_n, frame_rate_ext_d;
1643     float aspect;
1644
1645     skip_bits(&s->gb, 8); /* profil and level */
1646     s->progressive_sequence = get_bits1(&s->gb); /* progressive_sequence */
1647     skip_bits(&s->gb, 2); /* chroma_format */
1648     horiz_size_ext = get_bits(&s->gb, 2);
1649     vert_size_ext = get_bits(&s->gb, 2);
1650     s->width |= (horiz_size_ext << 12);
1651     s->height |= (vert_size_ext << 12);
1652     bit_rate_ext = get_bits(&s->gb, 12);  /* XXX: handle it */
1653     s->bit_rate = ((s->bit_rate / 400) | (bit_rate_ext << 12)) * 400;
1654     skip_bits1(&s->gb); /* marker */
1655     vbv_buf_ext = get_bits(&s->gb, 8);
1656
1657     s->low_delay = get_bits1(&s->gb);
1658     if(s->flags & CODEC_FLAG_LOW_DELAY) s->low_delay=1;
1659
1660     frame_rate_ext_n = get_bits(&s->gb, 2);
1661     frame_rate_ext_d = get_bits(&s->gb, 5);
1662     av_reduce(
1663         &s->avctx->frame_rate,
1664         &s->avctx->frame_rate_base,
1665         frame_rate_tab[s->frame_rate_index] * (frame_rate_ext_n+1),
1666         MPEG1_FRAME_RATE_BASE * (frame_rate_ext_d+1),
1667         1<<30);
1668
1669     dprintf("sequence extension\n");
1670     s->mpeg2 = 1;
1671     s->avctx->sub_id = 2; /* indicates mpeg2 found */
1672
1673     aspect= mpeg2_aspect[s->aspect_ratio_info];
1674     if(aspect>0.0)      s->avctx->aspect_ratio= s->width/(aspect*s->height);
1675     else if(aspect<0.0) s->avctx->aspect_ratio= -1.0/aspect;
1676 }
1677
1678 static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
1679 {
1680     int i, v, j;
1681
1682     dprintf("matrix extension\n");
1683
1684     if (get_bits1(&s->gb)) {
1685         for(i=0;i<64;i++) {
1686             v = get_bits(&s->gb, 8);
1687             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1688             s->intra_matrix[j] = v;
1689             s->chroma_intra_matrix[j] = v;
1690         }
1691     }
1692     if (get_bits1(&s->gb)) {
1693         for(i=0;i<64;i++) {
1694             v = get_bits(&s->gb, 8);
1695             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1696             s->inter_matrix[j] = v;
1697             s->chroma_inter_matrix[j] = v;
1698         }
1699     }
1700     if (get_bits1(&s->gb)) {
1701         for(i=0;i<64;i++) {
1702             v = get_bits(&s->gb, 8);
1703             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1704             s->chroma_intra_matrix[j] = v;
1705         }
1706     }
1707     if (get_bits1(&s->gb)) {
1708         for(i=0;i<64;i++) {
1709             v = get_bits(&s->gb, 8);
1710             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1711             s->chroma_inter_matrix[j] = v;
1712         }
1713     }
1714 }
1715
1716 static void mpeg_decode_picture_coding_extension(MpegEncContext *s)
1717 {
1718     s->full_pel[0] = s->full_pel[1] = 0;
1719     s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
1720     s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
1721     s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
1722     s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
1723     s->intra_dc_precision = get_bits(&s->gb, 2);
1724     s->picture_structure = get_bits(&s->gb, 2);
1725     s->top_field_first = get_bits1(&s->gb);
1726     s->frame_pred_frame_dct = get_bits1(&s->gb);
1727     s->concealment_motion_vectors = get_bits1(&s->gb);
1728     s->q_scale_type = get_bits1(&s->gb);
1729     s->intra_vlc_format = get_bits1(&s->gb);
1730     s->alternate_scan = get_bits1(&s->gb);
1731     s->repeat_first_field = get_bits1(&s->gb);
1732     s->chroma_420_type = get_bits1(&s->gb);
1733     s->progressive_frame = get_bits1(&s->gb);
1734
1735     if(s->picture_structure == PICT_FRAME)
1736         s->first_field=0;
1737     else{
1738         s->first_field ^= 1;
1739         memset(s->mbskip_table, 0, s->mb_stride*s->mb_height);
1740     }
1741
1742     if(s->alternate_scan){
1743         ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_alternate_vertical_scan);
1744         ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_alternate_vertical_scan);
1745         ff_init_scantable(s->dsp.idct_permutation, &s->intra_h_scantable, ff_alternate_vertical_scan);
1746         ff_init_scantable(s->dsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
1747     }else{
1748         ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_zigzag_direct);
1749         ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_zigzag_direct);
1750         ff_init_scantable(s->dsp.idct_permutation, &s->intra_h_scantable, ff_alternate_horizontal_scan);
1751         ff_init_scantable(s->dsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
1752     }
1753
1754     /* composite display not parsed */
1755     dprintf("intra_dc_precision=%d\n", s->intra_dc_precision);
1756     dprintf("picture_structure=%d\n", s->picture_structure);
1757     dprintf("top field first=%d\n", s->top_field_first);
1758     dprintf("repeat first field=%d\n", s->repeat_first_field);
1759     dprintf("conceal=%d\n", s->concealment_motion_vectors);
1760     dprintf("intra_vlc_format=%d\n", s->intra_vlc_format);
1761     dprintf("alternate_scan=%d\n", s->alternate_scan);
1762     dprintf("frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
1763     dprintf("progressive_frame=%d\n", s->progressive_frame);
1764 }
1765
1766 static void mpeg_decode_extension(AVCodecContext *avctx,
1767                                   uint8_t *buf, int buf_size)
1768 {
1769     Mpeg1Context *s1 = avctx->priv_data;
1770     MpegEncContext *s = &s1->mpeg_enc_ctx;
1771     int ext_type;
1772
1773     init_get_bits(&s->gb, buf, buf_size*8);
1774
1775     ext_type = get_bits(&s->gb, 4);
1776     switch(ext_type) {
1777     case 0x1:
1778         /* sequence ext */
1779         mpeg_decode_sequence_extension(s);
1780         break;
1781     case 0x3:
1782         /* quant matrix extension */
1783         mpeg_decode_quant_matrix_extension(s);
1784         break;
1785     case 0x8:
1786         /* picture extension */
1787         mpeg_decode_picture_coding_extension(s);
1788         break;
1789     }
1790 }
1791
1792 #define DECODE_SLICE_FATAL_ERROR -2
1793 #define DECODE_SLICE_ERROR -1
1794 #define DECODE_SLICE_OK 0
1795
1796 /**
1797  * decodes a slice.
1798  * @return DECODE_SLICE_FATAL_ERROR if a non recoverable error occured<br>
1799  *         DECODE_SLICE_ERROR if the slice is damaged<br>
1800  *         DECODE_SLICE_OK if this slice is ok<br>
1801  */
1802 static int mpeg_decode_slice(AVCodecContext *avctx,
1803                               AVFrame *pict,
1804                               int start_code,
1805                               uint8_t **buf, int buf_size)
1806 {
1807     Mpeg1Context *s1 = avctx->priv_data;
1808     MpegEncContext *s = &s1->mpeg_enc_ctx;
1809     int ret;
1810     const int field_pic= s->picture_structure != PICT_FRAME;
1811
1812     s->resync_mb_x= s->mb_x =
1813     s->resync_mb_y= s->mb_y = -1;
1814
1815     start_code = (start_code - 1) & 0xff;
1816     if (start_code >= s->mb_height){
1817         fprintf(stderr, "slice below image (%d >= %d)\n", start_code, s->mb_height);
1818         return -1;
1819     }
1820
1821     ff_mpeg1_clean_buffers(s);
1822     s->interlaced_dct = 0;
1823
1824     /* start frame decoding */
1825     if (s->first_slice) {
1826       if(s->first_field || s->picture_structure==PICT_FRAME){
1827         if(MPV_frame_start(s, avctx) < 0)
1828             return DECODE_SLICE_FATAL_ERROR;
1829
1830         ff_er_frame_start(s);
1831
1832         /* first check if we must repeat the frame */
1833         s->current_picture.repeat_pict = 0;
1834
1835         if (s->repeat_first_field) {
1836             if (s->progressive_sequence) {
1837                 if (s->top_field_first)
1838                     s->current_picture.repeat_pict = 4;
1839                 else
1840                     s->current_picture.repeat_pict = 2;
1841             } else if (s->progressive_frame) {
1842                 s->current_picture.repeat_pict = 1;
1843             }
1844         }
1845 //        printf("%d \n", s->current_picture.repeat_pict);
1846
1847         if(s->avctx->debug&FF_DEBUG_PICT_INFO){
1848              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",
1849                  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],
1850                  s->pict_type == I_TYPE ? "I" : (s->pict_type == P_TYPE ? "P" : (s->pict_type == B_TYPE ? "B" : "S")),
1851                  s->progressive_sequence ? "pro" :"", s->alternate_scan ? "alt" :"", s->top_field_first ? "top" :"",
1852                  s->intra_dc_precision, s->picture_structure, s->frame_pred_frame_dct, s->concealment_motion_vectors,
1853                  s->q_scale_type, s->intra_vlc_format, s->repeat_first_field, s->chroma_420_type ? "420" :"");
1854         }
1855       }else{ //second field
1856             int i;
1857
1858             if(!s->current_picture_ptr){
1859                 fprintf(stderr, "first field missing\n");
1860                 return -1;
1861             }
1862
1863             for(i=0; i<4; i++){
1864                 s->current_picture.data[i] = s->current_picture_ptr->data[i];
1865                 if(s->picture_structure == PICT_BOTTOM_FIELD){
1866                     s->current_picture.data[i] += s->current_picture_ptr->linesize[i];
1867                 }
1868             }
1869       }
1870     }
1871     s->first_slice = 0;
1872
1873     init_get_bits(&s->gb, *buf, buf_size*8);
1874
1875     s->qscale = get_qscale(s);
1876     if(s->qscale == 0){
1877         fprintf(stderr, "qscale == 0\n");
1878         return -1;
1879     }
1880
1881     /* extra slice info */
1882     while (get_bits1(&s->gb) != 0) {
1883         skip_bits(&s->gb, 8);
1884     }
1885
1886     s->mb_x=0;
1887
1888     for(;;) {
1889         int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
1890         if (code < 0){
1891             fprintf(stderr, "first mb_incr damaged\n");
1892             return -1;
1893         }
1894         if (code >= 33) {
1895             if (code == 33) {
1896                 s->mb_x += 33;
1897             }
1898             /* otherwise, stuffing, nothing to do */
1899         } else {
1900             s->mb_x += code;
1901             break;
1902         }
1903     }
1904
1905     s->resync_mb_x= s->mb_x;
1906     s->resync_mb_y= s->mb_y = start_code;
1907     s->mb_skip_run= 0;
1908
1909     for(;;) {
1910         s->dsp.clear_blocks(s->block[0]);
1911
1912         ret = mpeg_decode_mb(s, s->block);
1913
1914         dprintf("ret=%d\n", ret);
1915         if (ret < 0)
1916             return -1;
1917
1918         if(s->motion_val && s->pict_type != B_TYPE){ //note motion_val is normally NULL unless we want to extract the MVs
1919             const int wrap = s->block_wrap[0];
1920             const int xy = s->mb_x*2 + 1 + (s->mb_y*2 +1)*wrap;
1921             int motion_x, motion_y;
1922
1923             if (s->mb_intra) {
1924                 motion_x = motion_y = 0;
1925             }else if (s->mv_type == MV_TYPE_16X16) {
1926                 motion_x = s->mv[0][0][0];
1927                 motion_y = s->mv[0][0][1];
1928             } else /*if (s->mv_type == MV_TYPE_FIELD)*/ {
1929                 motion_x = s->mv[0][0][0] + s->mv[0][1][0];
1930                 motion_y = s->mv[0][0][1] + s->mv[0][1][1];
1931                 motion_x = (motion_x>>1) | (motion_x&1);
1932             }
1933             s->motion_val[xy][0] = motion_x;
1934             s->motion_val[xy][1] = motion_y;
1935             s->motion_val[xy + 1][0] = motion_x;
1936             s->motion_val[xy + 1][1] = motion_y;
1937             s->motion_val[xy + wrap][0] = motion_x;
1938             s->motion_val[xy + wrap][1] = motion_y;
1939             s->motion_val[xy + 1 + wrap][0] = motion_x;
1940             s->motion_val[xy + 1 + wrap][1] = motion_y;
1941         }
1942
1943         MPV_decode_mb(s, s->block);
1944
1945         if (++s->mb_x >= s->mb_width) {
1946             if(s->picture_structure==PICT_FRAME){
1947                 ff_draw_horiz_band(s, 16*s->mb_y, 16);
1948             }else{
1949                 if(!s->first_field){
1950                     ff_draw_horiz_band(s, 32*s->mb_y, 32);
1951                 }
1952             }
1953
1954             s->mb_x = 0;
1955             s->mb_y++;
1956
1957             if(s->mb_y<<field_pic >= s->mb_height){
1958                 int left= s->gb.size_in_bits - get_bits_count(&s->gb);
1959
1960                 if(left < 0 || (left && show_bits(&s->gb, FFMIN(left, 23)))
1961                    || (avctx->error_resilience >= FF_ER_AGGRESSIVE && left>8)){
1962                     fprintf(stderr, "end missmatch left=%d\n", left);
1963                     return -1;
1964                 }else
1965                     goto eos;
1966             }
1967         }
1968
1969         /* skip mb handling */
1970         if (s->mb_skip_run == -1) {
1971             /* read again increment */
1972             s->mb_skip_run = 0;
1973             for(;;) {
1974                 int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
1975                 if (code < 0){
1976                     fprintf(stderr, "mb incr damaged\n");
1977                     return -1;
1978                 }
1979                 if (code >= 33) {
1980                     if (code == 33) {
1981                         s->mb_skip_run += 33;
1982                     }else if(code == 35){
1983                         if(s->mb_skip_run != 0 || show_bits(&s->gb, 15) != 0){
1984                             fprintf(stderr, "slice missmatch\n");
1985                             return -1;
1986                         }
1987                         goto eos; /* end of slice */
1988                     }
1989                     /* otherwise, stuffing, nothing to do */
1990                 } else {
1991                     s->mb_skip_run += code;
1992                     break;
1993                 }
1994             }
1995         }
1996     }
1997 eos: // end of slice
1998     *buf += get_bits_count(&s->gb)/8 - 1;
1999 //printf("y %d %d %d %d\n", s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y);
2000     return 0;
2001 }
2002
2003 /**
2004  * handles slice ends.
2005  * @return 1 if it seems to be the last slice of
2006  */
2007 static int slice_end(AVCodecContext *avctx, AVFrame *pict)
2008 {
2009     Mpeg1Context *s1 = avctx->priv_data;
2010     MpegEncContext *s = &s1->mpeg_enc_ctx;
2011
2012     if (!s1->mpeg_enc_ctx_allocated)
2013         return 0;
2014
2015     /* end of slice reached */
2016     if (/*s->mb_y<<field_pic == s->mb_height &&*/ !s->first_field) {
2017         /* end of image */
2018
2019         if(s->mpeg2){
2020             s->current_picture_ptr->qscale_type= FF_QSCALE_TYPE_MPEG2;
2021         }else
2022             s->current_picture_ptr->qscale_type= FF_QSCALE_TYPE_MPEG1;
2023
2024         ff_er_frame_end(s);
2025
2026         MPV_frame_end(s);
2027
2028         if (s->pict_type == B_TYPE || s->low_delay) {
2029             *pict= *(AVFrame*)s->current_picture_ptr;
2030             ff_print_debug_info(s, s->current_picture_ptr);
2031         } else {
2032             s->picture_number++;
2033             /* latency of 1 frame for I and P frames */
2034             /* XXX: use another variable than picture_number */
2035             if (s->last_picture_ptr != NULL) {
2036                 *pict= *(AVFrame*)s->last_picture_ptr;
2037                  ff_print_debug_info(s, s->last_picture_ptr);
2038             }
2039         }
2040         return 1;
2041     } else {
2042         return 0;
2043     }
2044 }
2045
2046 static int mpeg1_decode_sequence(AVCodecContext *avctx,
2047                                  uint8_t *buf, int buf_size)
2048 {
2049     Mpeg1Context *s1 = avctx->priv_data;
2050     MpegEncContext *s = &s1->mpeg_enc_ctx;
2051     int width, height, i, v, j;
2052     float aspect;
2053
2054     init_get_bits(&s->gb, buf, buf_size*8);
2055
2056     width = get_bits(&s->gb, 12);
2057     height = get_bits(&s->gb, 12);
2058     s->aspect_ratio_info= get_bits(&s->gb, 4);
2059     if(!s->mpeg2){
2060         aspect= mpeg1_aspect[s->aspect_ratio_info];
2061         if(aspect!=0.0) avctx->aspect_ratio= width/(aspect*height);
2062     }
2063
2064     s->frame_rate_index = get_bits(&s->gb, 4);
2065     if (s->frame_rate_index == 0)
2066         return -1;
2067     s->bit_rate = get_bits(&s->gb, 18) * 400;
2068     if (get_bits1(&s->gb) == 0) /* marker */
2069         return -1;
2070     if (width <= 0 || height <= 0 ||
2071         (width % 2) != 0 || (height % 2) != 0)
2072         return -1;
2073     if (width != s->width ||
2074         height != s->height) {
2075         /* start new mpeg1 context decoding */
2076         s->out_format = FMT_MPEG1;
2077         if (s1->mpeg_enc_ctx_allocated) {
2078             MPV_common_end(s);
2079         }
2080         s->width = width;
2081         s->height = height;
2082         avctx->has_b_frames= 1;
2083         s->avctx = avctx;
2084         avctx->width = width;
2085         avctx->height = height;
2086         av_reduce(
2087             &avctx->frame_rate,
2088             &avctx->frame_rate_base,
2089             frame_rate_tab[s->frame_rate_index],
2090             MPEG1_FRAME_RATE_BASE, //FIXME store in allready reduced form
2091             1<<30
2092             );
2093         avctx->bit_rate = s->bit_rate;
2094
2095         if (MPV_common_init(s) < 0)
2096             return -1;
2097         s1->mpeg_enc_ctx_allocated = 1;
2098     }
2099
2100     skip_bits(&s->gb, 10); /* vbv_buffer_size */
2101     skip_bits(&s->gb, 1);
2102
2103     /* get matrix */
2104     if (get_bits1(&s->gb)) {
2105         for(i=0;i<64;i++) {
2106             v = get_bits(&s->gb, 8);
2107             j = s->intra_scantable.permutated[i];
2108             s->intra_matrix[j] = v;
2109             s->chroma_intra_matrix[j] = v;
2110         }
2111 #ifdef DEBUG
2112         dprintf("intra matrix present\n");
2113         for(i=0;i<64;i++)
2114             dprintf(" %d", s->intra_matrix[s->intra_scantable.permutated[i]]);
2115         printf("\n");
2116 #endif
2117     } else {
2118         for(i=0;i<64;i++) {
2119             int j= s->dsp.idct_permutation[i];
2120             v = ff_mpeg1_default_intra_matrix[i];
2121             s->intra_matrix[j] = v;
2122             s->chroma_intra_matrix[j] = v;
2123         }
2124     }
2125     if (get_bits1(&s->gb)) {
2126         for(i=0;i<64;i++) {
2127             v = get_bits(&s->gb, 8);
2128             j = s->intra_scantable.permutated[i];
2129             s->inter_matrix[j] = v;
2130             s->chroma_inter_matrix[j] = v;
2131         }
2132 #ifdef DEBUG
2133         dprintf("non intra matrix present\n");
2134         for(i=0;i<64;i++)
2135             dprintf(" %d", s->inter_matrix[s->intra_scantable.permutated[i]]);
2136         printf("\n");
2137 #endif
2138     } else {
2139         for(i=0;i<64;i++) {
2140             int j= s->dsp.idct_permutation[i];
2141             v = ff_mpeg1_default_non_intra_matrix[i];
2142             s->inter_matrix[j] = v;
2143             s->chroma_inter_matrix[j] = v;
2144         }
2145     }
2146
2147     /* we set mpeg2 parameters so that it emulates mpeg1 */
2148     s->progressive_sequence = 1;
2149     s->progressive_frame = 1;
2150     s->picture_structure = PICT_FRAME;
2151     s->frame_pred_frame_dct = 1;
2152     s->mpeg2 = 0;
2153     avctx->sub_id = 1; /* indicates mpeg1 */
2154     return 0;
2155 }
2156
2157 static void mpeg_decode_user_data(AVCodecContext *avctx,
2158                                   const uint8_t *buf, int buf_size)
2159 {
2160     const uint8_t *p;
2161     int len, flags;
2162     p = buf;
2163     len = buf_size;
2164
2165     /* we parse the DTG active format information */
2166     if (len >= 5 &&
2167         p[0] == 'D' && p[1] == 'T' && p[2] == 'G' && p[3] == '1') {
2168         flags = p[4];
2169         p += 5;
2170         len -= 5;
2171         if (flags & 0x80) {
2172             /* skip event id */
2173             if (len < 2)
2174                 return;
2175             p += 2;
2176             len -= 2;
2177         }
2178         if (flags & 0x40) {
2179             if (len < 1)
2180                 return;
2181             avctx->dtg_active_format = p[0] & 0x0f;
2182         }
2183     }
2184 }
2185
2186 /**
2187  * finds the end of the current frame in the bitstream.
2188  * @return the position of the first byte of the next frame, or -1
2189  */
2190 static int mpeg1_find_frame_end(MpegEncContext *s, uint8_t *buf, int buf_size){
2191     ParseContext *pc= &s->parse_context;
2192     int i;
2193     uint32_t state;
2194
2195     state= pc->state;
2196
2197     i=0;
2198     if(!pc->frame_start_found){
2199         for(i=0; i<buf_size; i++){
2200             state= (state<<8) | buf[i];
2201             if(state >= SLICE_MIN_START_CODE && state <= SLICE_MAX_START_CODE){
2202                 i++;
2203                 pc->frame_start_found=1;
2204                 break;
2205             }
2206         }
2207     }
2208
2209     if(pc->frame_start_found){
2210         for(; i<buf_size; i++){
2211             state= (state<<8) | buf[i];
2212             if((state&0xFFFFFF00) == 0x100){
2213                 if(state < SLICE_MIN_START_CODE || state > SLICE_MAX_START_CODE){
2214                     pc->frame_start_found=0;
2215                     pc->state=-1;
2216                     return i-3;
2217                 }
2218             }
2219         }
2220     }
2221     pc->state= state;
2222     return END_NOT_FOUND;
2223 }
2224
2225 /* handle buffering and image synchronisation */
2226 static int mpeg_decode_frame(AVCodecContext *avctx,
2227                              void *data, int *data_size,
2228                              uint8_t *buf, int buf_size)
2229 {
2230     Mpeg1Context *s = avctx->priv_data;
2231     uint8_t *buf_end, *buf_ptr;
2232     int ret, start_code, input_size;
2233     AVFrame *picture = data;
2234     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2235     dprintf("fill_buffer\n");
2236
2237     *data_size = 0;
2238
2239     /* special case for last picture */
2240     if (buf_size == 0) {
2241         if (s2->picture_number > 0) {
2242             *picture= *(AVFrame*)&s2->next_picture;
2243
2244             *data_size = sizeof(AVFrame);
2245         }
2246         return 0;
2247     }
2248
2249     if(s2->flags&CODEC_FLAG_TRUNCATED){
2250         int next= mpeg1_find_frame_end(s2, buf, buf_size);
2251
2252         if( ff_combine_frame(s2, next, &buf, &buf_size) < 0 )
2253             return buf_size;
2254     }
2255
2256     buf_ptr = buf;
2257     buf_end = buf + buf_size;
2258
2259 #if 0
2260     if (s->repeat_field % 2 == 1) {
2261         s->repeat_field++;
2262         //fprintf(stderr,"\nRepeating last frame: %d -> %d! pict: %d %d", avctx->frame_number-1, avctx->frame_number,
2263         //        s2->picture_number, s->repeat_field);
2264         if (avctx->flags & CODEC_FLAG_REPEAT_FIELD) {
2265             *data_size = sizeof(AVPicture);
2266             goto the_end;
2267         }
2268     }
2269 #endif
2270     for(;;) {
2271         /* find start next code */
2272         start_code = find_start_code(&buf_ptr, buf_end);
2273         if (start_code < 0){
2274             if (slice_end(avctx, picture)) {
2275                 if(s2->last_picture_ptr) //FIXME merge with the stuff in mpeg_decode_slice
2276                     *data_size = sizeof(AVPicture);
2277             }
2278             return FFMAX(0, buf_ptr - buf - s2->parse_context.last_index);
2279         }
2280
2281         input_size = buf_end - buf_ptr;
2282
2283         if(avctx->debug & FF_DEBUG_STARTCODE){
2284             printf("%3X at %d left %d\n", start_code, buf_ptr-buf, input_size);
2285         }
2286
2287                 /* prepare data for next start code */
2288                 switch(start_code) {
2289                 case SEQ_START_CODE:
2290                     mpeg1_decode_sequence(avctx, buf_ptr,
2291                                           input_size);
2292                     break;
2293
2294                 case PICTURE_START_CODE:
2295                     /* we have a complete image : we try to decompress it */
2296                     mpeg1_decode_picture(avctx,
2297                                          buf_ptr, input_size);
2298                     break;
2299                 case EXT_START_CODE:
2300                     mpeg_decode_extension(avctx,
2301                                           buf_ptr, input_size);
2302                     break;
2303                 case USER_START_CODE:
2304                     mpeg_decode_user_data(avctx,
2305                                           buf_ptr, input_size);
2306                     break;
2307                 case GOP_START_CODE:
2308                     s2->first_field=0;
2309                     break;
2310                 default:
2311                     if (start_code >= SLICE_MIN_START_CODE &&
2312                         start_code <= SLICE_MAX_START_CODE) {
2313
2314                         /* skip b frames if we dont have reference frames */
2315                         if(s2->last_picture_ptr==NULL && s2->pict_type==B_TYPE) break;
2316                         /* skip b frames if we are in a hurry */
2317                         if(avctx->hurry_up && s2->pict_type==B_TYPE) break;
2318                         /* skip everything if we are in a hurry>=5 */
2319                         if(avctx->hurry_up>=5) break;
2320
2321                         if (!s->mpeg_enc_ctx_allocated) break;
2322
2323                         ret = mpeg_decode_slice(avctx, picture,
2324                                                 start_code, &buf_ptr, input_size);
2325                         emms_c();
2326
2327                         if(ret < 0){
2328                             if(s2->resync_mb_x>=0 && s2->resync_mb_y>=0)
2329                                 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);
2330                             if(ret==DECODE_SLICE_FATAL_ERROR) return -1;
2331                         }else{
2332                             ff_er_add_slice(s2, s2->resync_mb_x, s2->resync_mb_y, s2->mb_x-1, s2->mb_y, AC_END|DC_END|MV_END);
2333                         }
2334                     }
2335                     break;
2336                 }
2337     }
2338 }
2339
2340 static int mpeg_decode_end(AVCodecContext *avctx)
2341 {
2342     Mpeg1Context *s = avctx->priv_data;
2343
2344     if (s->mpeg_enc_ctx_allocated)
2345         MPV_common_end(&s->mpeg_enc_ctx);
2346     return 0;
2347 }
2348
2349 AVCodec mpeg_decoder = {
2350     "mpegvideo",
2351     CODEC_TYPE_VIDEO,
2352     CODEC_ID_MPEG1VIDEO,
2353     sizeof(Mpeg1Context),
2354     mpeg_decode_init,
2355     NULL,
2356     mpeg_decode_end,
2357     mpeg_decode_frame,
2358     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED,
2359     .flush= ff_mpeg_flush,
2360 };