libavcodec/indeo4.c

   1 /*
   2  * Indeo Video Interactive v4 compatible decoder
   3  * Copyright (c) 2009-2011 Maxim Poliakovski
   4  *
   5  * This file is part of Libav.
   6  *
   7  * Libav is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * Libav is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with Libav; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 /**
  23  * @file
  24  * Indeo Video Interactive version 4 decoder
  25  *
  26  * Indeo 4 data is usually transported within .avi or .mov files.
  27  * Known FOURCCs: 'IV41'
  28  */
  29
  30 #define BITSTREAM_READER_LE
  31 #include "avcodec.h"
  32 #include "get_bits.h"
  33 #include "ivi_dsp.h"
  34 #include "ivi_common.h"
  35 #include "indeo4data.h"
  36
  37 /**
  38  *  Indeo 4 frame types.
  39  */
  40 enum {
  41     FRAMETYPE_INTRA       = 0,
  42     FRAMETYPE_INTRA1      = 1,  ///< intra frame with slightly different bitstream coding
  43     FRAMETYPE_INTER       = 2,  ///< non-droppable P-frame
  44     FRAMETYPE_BIDIR       = 3,  ///< bidirectional frame
  45     FRAMETYPE_INTER_NOREF = 4,  ///< droppable P-frame
  46     FRAMETYPE_NULL_FIRST  = 5,  ///< empty frame with no data
  47     FRAMETYPE_NULL_LAST   = 6   ///< empty frame with no data
  48 };
  49
  50 #define IVI4_PIC_SIZE_ESC   7
  51
  52
  53 static const struct {
  54     InvTransformPtr *inv_trans;
  55     DCTransformPtr  *dc_trans;
  56     int             is_2d_trans;
  57 } transforms[18] = {
  58     { ff_ivi_inverse_haar_8x8,  ff_ivi_dc_haar_2d,       1 },
  59     { NULL, NULL, 0 }, /* inverse Haar 8x1 */
  60     { NULL, NULL, 0 }, /* inverse Haar 1x8 */
  61     { ff_ivi_put_pixels_8x8,    ff_ivi_put_dc_pixel_8x8, 1 },
  62     { ff_ivi_inverse_slant_8x8, ff_ivi_dc_slant_2d,      1 },
  63     { ff_ivi_row_slant8,        ff_ivi_dc_row_slant,     1 },
  64     { ff_ivi_col_slant8,        ff_ivi_dc_col_slant,     1 },
  65     { NULL, NULL, 0 }, /* inverse DCT 8x8 */
  66     { NULL, NULL, 0 }, /* inverse DCT 8x1 */
  67     { NULL, NULL, 0 }, /* inverse DCT 1x8 */
  68     { NULL, NULL, 0 }, /* inverse Haar 4x4 */
  69     { ff_ivi_inverse_slant_4x4, ff_ivi_dc_slant_2d,      1 },
  70     { NULL, NULL, 0 }, /* no transform 4x4 */
  71     { NULL, NULL, 0 }, /* inverse Haar 1x4 */
  72     { NULL, NULL, 0 }, /* inverse Haar 4x1 */
  73     { NULL, NULL, 0 }, /* inverse slant 1x4 */
  74     { NULL, NULL, 0 }, /* inverse slant 4x1 */
  75     { NULL, NULL, 0 }, /* inverse DCT 4x4 */
  76 };
  77
  78 /**
  79  *  Decode subdivision of a plane.
  80  *  This is a simplified version that checks for two supported subdivisions:
  81  *  - 1 wavelet band  per plane, size factor 1:1, code pattern: 3
  82  *  - 4 wavelet bands per plane, size factor 1:4, code pattern: 2,3,3,3,3
  83  *  Anything else is either unsupported or corrupt.
  84  *
  85  *  @param[in,out] gb    the GetBit context
  86  *  @return        number of wavelet bands or 0 on error
  87  */
  88 static int decode_plane_subdivision(GetBitContext *gb)
  89 {
  90     int i;
  91
  92     switch (get_bits(gb, 2)) {
  93     case 3:
  94         return 1;
  95     case 2:
  96         for (i = 0; i < 4; i++)
  97             if (get_bits(gb, 2) != 3)
  98                 return 0;
  99         return 4;
 100     default:
 101         return 0;
 102     }
 103 }
 104
 105 static inline int scale_tile_size(int def_size, int size_factor)
 106 {
 107     return size_factor == 15 ? def_size : (size_factor + 1) << 5;
 108 }
 109
 110 /**
 111  *  Decode Indeo 4 picture header.
 112  *
 113  *  @param[in,out] ctx       pointer to the decoder context
 114  *  @param[in]     avctx     pointer to the AVCodecContext
 115  *  @return        result code: 0 = OK, negative number = error
 116  */
 117 static int decode_pic_hdr(IVI45DecContext *ctx, AVCodecContext *avctx)
 118 {
 119     int             pic_size_indx, i, p;
 120     IVIPicConfig    pic_conf;
 121
 122     if (get_bits(&ctx->gb, 18) != 0x3FFF8) {
 123         av_log(avctx, AV_LOG_ERROR, "Invalid picture start code!\n");
 124         return AVERROR_INVALIDDATA;
 125     }
 126
 127     ctx->prev_frame_type = ctx->frame_type;
 128     ctx->frame_type      = get_bits(&ctx->gb, 3);
 129     if (ctx->frame_type == 7) {
 130         av_log(avctx, AV_LOG_ERROR, "Invalid frame type: %d\n", ctx->frame_type);
 131         return AVERROR_INVALIDDATA;
 132     }
 133
 134 #if IVI4_STREAM_ANALYSER
 135     if (ctx->frame_type == FRAMETYPE_BIDIR)
 136         ctx->has_b_frames = 1;
 137 #endif
 138
 139     ctx->transp_status = get_bits1(&ctx->gb);
 140 #if IVI4_STREAM_ANALYSER
 141     if (ctx->transp_status) {
 142         ctx->has_transp = 1;
 143     }
 144 #endif
 145
 146     /* unknown bit: Mac decoder ignores this bit, XANIM returns error */
 147     if (get_bits1(&ctx->gb)) {
 148         av_log(avctx, AV_LOG_ERROR, "Sync bit is set!\n");
 149         return AVERROR_INVALIDDATA;
 150     }
 151
 152     ctx->data_size = get_bits1(&ctx->gb) ? get_bits(&ctx->gb, 24) : 0;
 153
 154     /* null frames don't contain anything else so we just return */
 155     if (ctx->frame_type >= FRAMETYPE_NULL_FIRST) {
 156         av_dlog(avctx, "Null frame encountered!\n");
 157         return 0;
 158     }
 159
 160     /* Check key lock status. If enabled - ignore lock word.         */
 161     /* Usually we have to prompt the user for the password, but      */
 162     /* we don't do that because Indeo 4 videos can be decoded anyway */
 163     if (get_bits1(&ctx->gb)) {
 164         skip_bits_long(&ctx->gb, 32);
 165         av_dlog(avctx, "Password-protected clip!\n");
 166     }
 167
 168     pic_size_indx = get_bits(&ctx->gb, 3);
 169     if (pic_size_indx == IVI4_PIC_SIZE_ESC) {
 170         pic_conf.pic_height = get_bits(&ctx->gb, 16);
 171         pic_conf.pic_width  = get_bits(&ctx->gb, 16);
 172     } else {
 173         pic_conf.pic_height = ivi4_common_pic_sizes[pic_size_indx * 2 + 1];
 174         pic_conf.pic_width  = ivi4_common_pic_sizes[pic_size_indx * 2    ];
 175     }
 176
 177     /* Decode tile dimensions. */
 178     if (get_bits1(&ctx->gb)) {
 179         pic_conf.tile_height = scale_tile_size(pic_conf.pic_height, get_bits(&ctx->gb, 4));
 180         pic_conf.tile_width  = scale_tile_size(pic_conf.pic_width,  get_bits(&ctx->gb, 4));
 181 #if IVI4_STREAM_ANALYSER
 182         ctx->uses_tiling = 1;
 183 #endif
 184     } else {
 185         pic_conf.tile_height = pic_conf.pic_height;
 186         pic_conf.tile_width  = pic_conf.pic_width;
 187     }
 188
 189     /* Decode chroma subsampling. We support only 4:4 aka YVU9. */
 190     if (get_bits(&ctx->gb, 2)) {
 191         av_log(avctx, AV_LOG_ERROR, "Only YVU9 picture format is supported!\n");
 192         return AVERROR_INVALIDDATA;
 193     }
 194     pic_conf.chroma_height = (pic_conf.pic_height + 3) >> 2;
 195     pic_conf.chroma_width  = (pic_conf.pic_width  + 3) >> 2;
 196
 197     /* decode subdivision of the planes */
 198     pic_conf.luma_bands = decode_plane_subdivision(&ctx->gb);
 199     if (pic_conf.luma_bands)
 200         pic_conf.chroma_bands = decode_plane_subdivision(&ctx->gb);
 201     ctx->is_scalable = pic_conf.luma_bands != 1 || pic_conf.chroma_bands != 1;
 202     if (ctx->is_scalable && (pic_conf.luma_bands != 4 || pic_conf.chroma_bands != 1)) {
 203         av_log(avctx, AV_LOG_ERROR, "Scalability: unsupported subdivision! Luma bands: %d, chroma bands: %d\n",
 204                pic_conf.luma_bands, pic_conf.chroma_bands);
 205         return AVERROR_INVALIDDATA;
 206     }
 207
 208     /* check if picture layout was changed and reallocate buffers */
 209     if (ivi_pic_config_cmp(&pic_conf, &ctx->pic_conf)) {
 210         if (ff_ivi_init_planes(ctx->planes, &pic_conf)) {
 211             av_log(avctx, AV_LOG_ERROR, "Couldn't reallocate color planes!\n");
 212             return AVERROR(ENOMEM);
 213         }
 214
 215         ctx->pic_conf = pic_conf;
 216
 217         /* set default macroblock/block dimensions */
 218         for (p = 0; p <= 2; p++) {
 219             for (i = 0; i < (!p ? pic_conf.luma_bands : pic_conf.chroma_bands); i++) {
 220                 ctx->planes[p].bands[i].mb_size  = !p ? (!ctx->is_scalable ? 16 : 8) : 4;
 221                 ctx->planes[p].bands[i].blk_size = !p ? 8 : 4;
 222             }
 223         }
 224
 225         if (ff_ivi_init_tiles(ctx->planes, ctx->pic_conf.tile_width,
 226                               ctx->pic_conf.tile_height)) {
 227             av_log(avctx, AV_LOG_ERROR,
 228                    "Couldn't reallocate internal structures!\n");
 229             return AVERROR(ENOMEM);
 230         }
 231     }
 232
 233     ctx->frame_num = get_bits1(&ctx->gb) ? get_bits(&ctx->gb, 20) : 0;
 234
 235     /* skip decTimeEst field if present */
 236     if (get_bits1(&ctx->gb))
 237         skip_bits(&ctx->gb, 8);
 238
 239     /* decode macroblock and block huffman codebooks */
 240     if (ff_ivi_dec_huff_desc(&ctx->gb, get_bits1(&ctx->gb), IVI_MB_HUFF,  &ctx->mb_vlc,  avctx) ||
 241         ff_ivi_dec_huff_desc(&ctx->gb, get_bits1(&ctx->gb), IVI_BLK_HUFF, &ctx->blk_vlc, avctx))
 242         return AVERROR_INVALIDDATA;
 243
 244     ctx->rvmap_sel = get_bits1(&ctx->gb) ? get_bits(&ctx->gb, 3) : 8;
 245
 246     ctx->in_imf = get_bits1(&ctx->gb);
 247     ctx->in_q   = get_bits1(&ctx->gb);
 248
 249     ctx->pic_glob_quant = get_bits(&ctx->gb, 5);
 250
 251     /* TODO: ignore this parameter if unused */
 252     ctx->unknown1 = get_bits1(&ctx->gb) ? get_bits(&ctx->gb, 3) : 0;
 253
 254     ctx->checksum = get_bits1(&ctx->gb) ? get_bits(&ctx->gb, 16) : 0;
 255
 256     /* skip picture header extension if any */
 257     while (get_bits1(&ctx->gb)) {
 258         av_dlog(avctx, "Pic hdr extension encountered!\n");
 259         skip_bits(&ctx->gb, 8);
 260     }
 261
 262     if (get_bits1(&ctx->gb)) {
 263         av_log(avctx, AV_LOG_ERROR, "Bad blocks bits encountered!\n");
 264     }
 265
 266     align_get_bits(&ctx->gb);
 267
 268     return 0;
 269 }
 270
 271
 272 /**
 273  *  Decode Indeo 4 band header.
 274  *
 275  *  @param[in,out] ctx       pointer to the decoder context
 276  *  @param[in,out] band      pointer to the band descriptor
 277  *  @param[in]     avctx     pointer to the AVCodecContext
 278  *  @return        result code: 0 = OK, negative number = error
 279  */
 280 static int decode_band_hdr(IVI45DecContext *ctx, IVIBandDesc *band,
 281                            AVCodecContext *avctx)
 282 {
 283     int plane, band_num, indx, transform_id, scan_indx;
 284     int i;
 285
 286     plane    = get_bits(&ctx->gb, 2);
 287     band_num = get_bits(&ctx->gb, 4);
 288     if (band->plane != plane || band->band_num != band_num) {
 289         av_log(avctx, AV_LOG_ERROR, "Invalid band header sequence!\n");
 290         return AVERROR_INVALIDDATA;
 291     }
 292
 293     band->is_empty = get_bits1(&ctx->gb);
 294     if (!band->is_empty) {
 295         /* skip header size
 296          * If header size is not given, header size is 4 bytes. */
 297         if (get_bits1(&ctx->gb))
 298             skip_bits(&ctx->gb, 16);
 299
 300         band->is_halfpel = get_bits(&ctx->gb, 2);
 301         if (band->is_halfpel >= 2) {
 302             av_log(avctx, AV_LOG_ERROR, "Invalid/unsupported mv resolution: %d!\n",
 303                    band->is_halfpel);
 304             return AVERROR_INVALIDDATA;
 305         }
 306 #if IVI4_STREAM_ANALYSER
 307         if (!band->is_halfpel)
 308             ctx->uses_fullpel = 1;
 309 #endif
 310
 311         band->checksum_present = get_bits1(&ctx->gb);
 312         if (band->checksum_present)
 313             band->checksum = get_bits(&ctx->gb, 16);
 314
 315         indx = get_bits(&ctx->gb, 2);
 316         if (indx == 3) {
 317             av_log(avctx, AV_LOG_ERROR, "Invalid block size!\n");
 318             return AVERROR_INVALIDDATA;
 319         }
 320         band->mb_size  = 16 >> indx;
 321         band->blk_size = 8 >> (indx >> 1);
 322
 323         band->inherit_mv     = get_bits1(&ctx->gb);
 324         band->inherit_qdelta = get_bits1(&ctx->gb);
 325
 326         band->glob_quant = get_bits(&ctx->gb, 5);
 327
 328         if (!get_bits1(&ctx->gb) || ctx->frame_type == FRAMETYPE_INTRA) {
 329             transform_id = get_bits(&ctx->gb, 5);
 330             if (transform_id >= FF_ARRAY_ELEMS(transforms) ||
 331                 !transforms[transform_id].inv_trans) {
 332                 av_log_ask_for_sample(avctx, "Unimplemented transform: %d!\n", transform_id);
 333                 return AVERROR_PATCHWELCOME;
 334             }
 335             if ((transform_id >= 7 && transform_id <= 9) ||
 336                  transform_id == 17) {
 337                 av_log_ask_for_sample(avctx, "DCT transform not supported yet!\n");
 338                 return AVERROR_PATCHWELCOME;
 339             }
 340
 341 #if IVI4_STREAM_ANALYSER
 342             if ((transform_id >= 0 && transform_id <= 2) || transform_id == 10)
 343                 ctx->uses_haar = 1;
 344 #endif
 345
 346             band->inv_transform = transforms[transform_id].inv_trans;
 347             band->dc_transform  = transforms[transform_id].dc_trans;
 348             band->is_2d_trans   = transforms[transform_id].is_2d_trans;
 349
 350             scan_indx = get_bits(&ctx->gb, 4);
 351             if (scan_indx == 15) {
 352                 av_log(avctx, AV_LOG_ERROR, "Custom scan pattern encountered!\n");
 353                 return AVERROR_INVALIDDATA;
 354             }
 355             band->scan = scan_index_to_tab[scan_indx];
 356
 357             band->quant_mat = get_bits(&ctx->gb, 5);
 358             if (band->quant_mat == 31) {
 359                 av_log(avctx, AV_LOG_ERROR, "Custom quant matrix encountered!\n");
 360                 return AVERROR_INVALIDDATA;
 361             }
 362         }
 363
 364         /* decode block huffman codebook */
 365         if (ff_ivi_dec_huff_desc(&ctx->gb, get_bits1(&ctx->gb), IVI_BLK_HUFF,
 366                                  &band->blk_vlc, avctx))
 367             return AVERROR_INVALIDDATA;
 368
 369         /* select appropriate rvmap table for this band */
 370         band->rvmap_sel = get_bits1(&ctx->gb) ? get_bits(&ctx->gb, 3) : 8;
 371
 372         /* decode rvmap probability corrections if any */
 373         band->num_corr = 0; /* there is no corrections */
 374         if (get_bits1(&ctx->gb)) {
 375             band->num_corr = get_bits(&ctx->gb, 8); /* get number of correction pairs */
 376             if (band->num_corr > 61) {
 377                 av_log(avctx, AV_LOG_ERROR, "Too many corrections: %d\n",
 378                        band->num_corr);
 379                 return AVERROR_INVALIDDATA;
 380             }
 381
 382             /* read correction pairs */
 383             for (i = 0; i < band->num_corr * 2; i++)
 384                 band->corr[i] = get_bits(&ctx->gb, 8);
 385         }
 386     }
 387
 388     if (band->blk_size == 8) {
 389         band->intra_base = &ivi4_quant_8x8_intra[quant_index_to_tab[band->quant_mat]][0];
 390         band->inter_base = &ivi4_quant_8x8_inter[quant_index_to_tab[band->quant_mat]][0];
 391     } else {
 392         band->intra_base = &ivi4_quant_4x4_intra[quant_index_to_tab[band->quant_mat]][0];
 393         band->inter_base = &ivi4_quant_4x4_inter[quant_index_to_tab[band->quant_mat]][0];
 394     }
 395
 396     /* Indeo 4 doesn't use scale tables */
 397     band->intra_scale = NULL;
 398     band->inter_scale = NULL;
 399
 400     align_get_bits(&ctx->gb);
 401
 402     return 0;
 403 }
 404
 405
 406 /**
 407  *  Decode information (block type, cbp, quant delta, motion vector)
 408  *  for all macroblocks in the current tile.
 409  *
 410  *  @param[in,out] ctx       pointer to the decoder context
 411  *  @param[in,out] band      pointer to the band descriptor
 412  *  @param[in,out] tile      pointer to the tile descriptor
 413  *  @param[in]     avctx     pointer to the AVCodecContext
 414  *  @return        result code: 0 = OK, negative number = error
 415  */
 416 static int decode_mb_info(IVI45DecContext *ctx, IVIBandDesc *band,
 417                           IVITile *tile, AVCodecContext *avctx)
 418 {
 419     int         x, y, mv_x, mv_y, mv_delta, offs, mb_offset, blks_per_mb,
 420                 mv_scale, mb_type_bits;
 421     IVIMbInfo   *mb, *ref_mb;
 422     int         row_offset = band->mb_size * band->pitch;
 423
 424     mb     = tile->mbs;
 425     ref_mb = tile->ref_mbs;
 426     offs   = tile->ypos * band->pitch + tile->xpos;
 427
 428     blks_per_mb  = band->mb_size   != band->blk_size  ? 4 : 1;
 429     mb_type_bits = ctx->frame_type == FRAMETYPE_BIDIR ? 2 : 1;
 430
 431     /* scale factor for motion vectors */
 432     mv_scale = (ctx->planes[0].bands[0].mb_size >> 3) - (band->mb_size >> 3);
 433     mv_x = mv_y = 0;
 434
 435     for (y = tile->ypos; y < tile->ypos + tile->height; y += band->mb_size) {
 436         mb_offset = offs;
 437
 438         for (x = tile->xpos; x < tile->xpos + tile->width; x += band->mb_size) {
 439             mb->xpos     = x;
 440             mb->ypos     = y;
 441             mb->buf_offs = mb_offset;
 442
 443             if (get_bits1(&ctx->gb)) {
 444                 if (ctx->frame_type == FRAMETYPE_INTRA) {
 445                     av_log(avctx, AV_LOG_ERROR, "Empty macroblock in an INTRA picture!\n");
 446                     return AVERROR_INVALIDDATA;
 447                 }
 448                 mb->type = 1; /* empty macroblocks are always INTER */
 449                 mb->cbp  = 0; /* all blocks are empty */
 450
 451                 mb->q_delta = 0;
 452                 if (!band->plane && !band->band_num && ctx->in_q) {
 453                     mb->q_delta = get_vlc2(&ctx->gb, ctx->mb_vlc.tab->table,
 454                                            IVI_VLC_BITS, 1);
 455                     mb->q_delta = IVI_TOSIGNED(mb->q_delta);
 456                 }
 457
 458                 mb->mv_x = mb->mv_y = 0; /* no motion vector coded */
 459                 if (band->inherit_mv) {
 460                     /* motion vector inheritance */
 461                     if (mv_scale) {
 462                         mb->mv_x = ivi_scale_mv(ref_mb->mv_x, mv_scale);
 463                         mb->mv_y = ivi_scale_mv(ref_mb->mv_y, mv_scale);
 464                     } else {
 465                         mb->mv_x = ref_mb->mv_x;
 466                         mb->mv_y = ref_mb->mv_y;
 467                     }
 468                 }
 469             } else {
 470                 if (band->inherit_mv) {
 471                     mb->type = ref_mb->type; /* copy mb_type from corresponding reference mb */
 472                 } else if (ctx->frame_type == FRAMETYPE_INTRA ||
 473                            ctx->frame_type == FRAMETYPE_INTRA1) {
 474                     mb->type = 0; /* mb_type is always INTRA for intra-frames */
 475                 } else {
 476                     mb->type = get_bits(&ctx->gb, mb_type_bits);
 477                 }
 478
 479                 mb->cbp = get_bits(&ctx->gb, blks_per_mb);
 480
 481                 mb->q_delta = 0;
 482                 if (band->inherit_qdelta) {
 483                     if (ref_mb) mb->q_delta = ref_mb->q_delta;
 484                 } else if (mb->cbp || (!band->plane && !band->band_num &&
 485                            ctx->in_q)) {
 486                     mb->q_delta = get_vlc2(&ctx->gb, ctx->mb_vlc.tab->table,
 487                                            IVI_VLC_BITS, 1);
 488                     mb->q_delta = IVI_TOSIGNED(mb->q_delta);
 489                 }
 490
 491                 if (!mb->type) {
 492                     mb->mv_x = mb->mv_y = 0; /* there is no motion vector in intra-macroblocks */
 493                 } else {
 494                     if (band->inherit_mv) {
 495                         /* motion vector inheritance */
 496                         if (mv_scale) {
 497                             mb->mv_x = ivi_scale_mv(ref_mb->mv_x, mv_scale);
 498                             mb->mv_y = ivi_scale_mv(ref_mb->mv_y, mv_scale);
 499                         } else {
 500                             mb->mv_x = ref_mb->mv_x;
 501                             mb->mv_y = ref_mb->mv_y;
 502                         }
 503                     } else {
 504                         /* decode motion vector deltas */
 505                         mv_delta = get_vlc2(&ctx->gb, ctx->mb_vlc.tab->table,
 506                                             IVI_VLC_BITS, 1);
 507                         mv_y += IVI_TOSIGNED(mv_delta);
 508                         mv_delta = get_vlc2(&ctx->gb, ctx->mb_vlc.tab->table,
 509                                             IVI_VLC_BITS, 1);
 510                         mv_x += IVI_TOSIGNED(mv_delta);
 511                         mb->mv_x = mv_x;
 512                         mb->mv_y = mv_y;
 513                     }
 514                 }
 515             }
 516
 517             mb++;
 518             if (ref_mb)
 519                 ref_mb++;
 520             mb_offset += band->mb_size;
 521         }
 522
 523         offs += row_offset;
 524     }
 525
 526     align_get_bits(&ctx->gb);
 527
 528     return 0;
 529 }
 530
 531
 532 /**
 533  *  Rearrange decoding and reference buffers.
 534  *
 535  *  @param[in,out] ctx       pointer to the decoder context
 536  */
 537 static void switch_buffers(IVI45DecContext *ctx)
 538 {
 539     switch (ctx->prev_frame_type) {
 540     case FRAMETYPE_INTRA:
 541     case FRAMETYPE_INTRA1:
 542     case FRAMETYPE_INTER:
 543         ctx->buf_switch ^= 1;
 544         ctx->dst_buf     = ctx->buf_switch;
 545         ctx->ref_buf     = ctx->buf_switch ^ 1;
 546         break;
 547     case FRAMETYPE_INTER_NOREF:
 548         break;
 549     }
 550
 551     switch (ctx->frame_type) {
 552     case FRAMETYPE_INTRA:
 553     case FRAMETYPE_INTRA1:
 554         ctx->buf_switch = 0;
 555         /* FALLTHROUGH */
 556     case FRAMETYPE_INTER:
 557         ctx->dst_buf = ctx->buf_switch;
 558         ctx->ref_buf = ctx->buf_switch ^ 1;
 559         break;
 560     case FRAMETYPE_INTER_NOREF:
 561     case FRAMETYPE_NULL_FIRST:
 562     case FRAMETYPE_NULL_LAST:
 563         break;
 564     }
 565 }
 566
 567
 568 static int is_nonnull_frame(IVI45DecContext *ctx)
 569 {
 570     return ctx->frame_type < FRAMETYPE_NULL_FIRST;
 571 }
 572
 573
 574 static av_cold int decode_init(AVCodecContext *avctx)
 575 {
 576     IVI45DecContext *ctx = avctx->priv_data;
 577
 578     ff_ivi_init_static_vlc();
 579
 580     /* copy rvmap tables in our context so we can apply changes to them */
 581     memcpy(ctx->rvmap_tabs, ff_ivi_rvmap_tabs, sizeof(ff_ivi_rvmap_tabs));
 582
 583     /* Force allocation of the internal buffers */
 584     /* during picture header decoding.          */
 585     ctx->pic_conf.pic_width  = 0;
 586     ctx->pic_conf.pic_height = 0;
 587
 588     avctx->pix_fmt = AV_PIX_FMT_YUV410P;
 589
 590     ctx->decode_pic_hdr   = decode_pic_hdr;
 591     ctx->decode_band_hdr  = decode_band_hdr;
 592     ctx->decode_mb_info   = decode_mb_info;
 593     ctx->switch_buffers   = switch_buffers;
 594     ctx->is_nonnull_frame = is_nonnull_frame;
 595
 596     return 0;
 597 }
 598
 599
 600 AVCodec ff_indeo4_decoder = {
 601     .name           = "indeo4",
 602     .type           = AVMEDIA_TYPE_VIDEO,
 603     .id             = AV_CODEC_ID_INDEO4,
 604     .priv_data_size = sizeof(IVI45DecContext),
 605     .init           = decode_init,
 606     .close          = ff_ivi_decode_close,
 607     .decode         = ff_ivi_decode_frame,
 608     .long_name      = NULL_IF_CONFIG_SMALL("Intel Indeo Video Interactive 4"),
 609     .capabilities   = CODEC_CAP_DR1,
 610 };