Subversion Repositories Kolibri OS

Rev

Go to most recent revision | Blame | Last modification | View Log | RSS feed

  1. /*
  2.  * Indeo Video Interactive v4 compatible decoder
  3.  * Copyright (c) 2009-2011 Maxim Poliakovski
  4.  *
  5.  * This file is part of FFmpeg.
  6.  *
  7.  * FFmpeg 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.  * FFmpeg 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 FFmpeg; 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.     { ff_ivi_row_haar8,         ff_ivi_dc_haar_2d,       0 },
  60.     { ff_ivi_col_haar8,         ff_ivi_dc_haar_2d,       0 },
  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.     { ff_ivi_inverse_haar_4x4,  ff_ivi_dc_haar_2d,       1 },
  69.     { ff_ivi_inverse_slant_4x4, ff_ivi_dc_slant_2d,      1 },
  70.     { NULL, NULL, 0 }, /* no transform 4x4 */
  71.     { ff_ivi_row_haar4,         ff_ivi_dc_haar_2d,       0 },
  72.     { ff_ivi_col_haar4,         ff_ivi_dc_haar_2d,       0 },
  73.     { ff_ivi_row_slant4,        ff_ivi_dc_row_slant,     0 },
  74.     { ff_ivi_col_slant4,        ff_ivi_dc_col_slant,     0 },
  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.     pic_conf.chroma_bands = 0;
  200.     if (pic_conf.luma_bands)
  201.         pic_conf.chroma_bands = decode_plane_subdivision(&ctx->gb);
  202.     ctx->is_scalable = pic_conf.luma_bands != 1 || pic_conf.chroma_bands != 1;
  203.     if (ctx->is_scalable && (pic_conf.luma_bands != 4 || pic_conf.chroma_bands != 1)) {
  204.         av_log(avctx, AV_LOG_ERROR, "Scalability: unsupported subdivision! Luma bands: %d, chroma bands: %d\n",
  205.                pic_conf.luma_bands, pic_conf.chroma_bands);
  206.         return AVERROR_INVALIDDATA;
  207.     }
  208.  
  209.     /* check if picture layout was changed and reallocate buffers */
  210.     if (ivi_pic_config_cmp(&pic_conf, &ctx->pic_conf)) {
  211.         if (ff_ivi_init_planes(ctx->planes, &pic_conf)) {
  212.             av_log(avctx, AV_LOG_ERROR, "Couldn't reallocate color planes!\n");
  213.             ctx->pic_conf.luma_bands = 0;
  214.             return AVERROR(ENOMEM);
  215.         }
  216.  
  217.         ctx->pic_conf = pic_conf;
  218.  
  219.         /* set default macroblock/block dimensions */
  220.         for (p = 0; p <= 2; p++) {
  221.             for (i = 0; i < (!p ? pic_conf.luma_bands : pic_conf.chroma_bands); i++) {
  222.                 ctx->planes[p].bands[i].mb_size  = !p ? (!ctx->is_scalable ? 16 : 8) : 4;
  223.                 ctx->planes[p].bands[i].blk_size = !p ? 8 : 4;
  224.             }
  225.         }
  226.  
  227.         if (ff_ivi_init_tiles(ctx->planes, ctx->pic_conf.tile_width,
  228.                               ctx->pic_conf.tile_height)) {
  229.             av_log(avctx, AV_LOG_ERROR,
  230.                    "Couldn't reallocate internal structures!\n");
  231.             return AVERROR(ENOMEM);
  232.         }
  233.     }
  234.  
  235.     ctx->frame_num = get_bits1(&ctx->gb) ? get_bits(&ctx->gb, 20) : 0;
  236.  
  237.     /* skip decTimeEst field if present */
  238.     if (get_bits1(&ctx->gb))
  239.         skip_bits(&ctx->gb, 8);
  240.  
  241.     /* decode macroblock and block huffman codebooks */
  242.     if (ff_ivi_dec_huff_desc(&ctx->gb, get_bits1(&ctx->gb), IVI_MB_HUFF,  &ctx->mb_vlc,  avctx) ||
  243.         ff_ivi_dec_huff_desc(&ctx->gb, get_bits1(&ctx->gb), IVI_BLK_HUFF, &ctx->blk_vlc, avctx))
  244.         return AVERROR_INVALIDDATA;
  245.  
  246.     ctx->rvmap_sel = get_bits1(&ctx->gb) ? get_bits(&ctx->gb, 3) : 8;
  247.  
  248.     ctx->in_imf = get_bits1(&ctx->gb);
  249.     ctx->in_q   = get_bits1(&ctx->gb);
  250.  
  251.     ctx->pic_glob_quant = get_bits(&ctx->gb, 5);
  252.  
  253.     /* TODO: ignore this parameter if unused */
  254.     ctx->unknown1 = get_bits1(&ctx->gb) ? get_bits(&ctx->gb, 3) : 0;
  255.  
  256.     ctx->checksum = get_bits1(&ctx->gb) ? get_bits(&ctx->gb, 16) : 0;
  257.  
  258.     /* skip picture header extension if any */
  259.     while (get_bits1(&ctx->gb)) {
  260.         av_dlog(avctx, "Pic hdr extension encountered!\n");
  261.         skip_bits(&ctx->gb, 8);
  262.     }
  263.  
  264.     if (get_bits1(&ctx->gb)) {
  265.         av_log(avctx, AV_LOG_ERROR, "Bad blocks bits encountered!\n");
  266.     }
  267.  
  268.     align_get_bits(&ctx->gb);
  269.  
  270.     return 0;
  271. }
  272.  
  273.  
  274. /**
  275.  *  Decode Indeo 4 band header.
  276.  *
  277.  *  @param[in,out] ctx       pointer to the decoder context
  278.  *  @param[in,out] band      pointer to the band descriptor
  279.  *  @param[in]     avctx     pointer to the AVCodecContext
  280.  *  @return        result code: 0 = OK, negative number = error
  281.  */
  282. static int decode_band_hdr(IVI45DecContext *ctx, IVIBandDesc *band,
  283.                            AVCodecContext *avctx)
  284. {
  285.     int plane, band_num, indx, transform_id, scan_indx;
  286.     int i;
  287.  
  288.     plane    = get_bits(&ctx->gb, 2);
  289.     band_num = get_bits(&ctx->gb, 4);
  290.     if (band->plane != plane || band->band_num != band_num) {
  291.         av_log(avctx, AV_LOG_ERROR, "Invalid band header sequence!\n");
  292.         return AVERROR_INVALIDDATA;
  293.     }
  294.  
  295.     band->is_empty = get_bits1(&ctx->gb);
  296.     if (!band->is_empty) {
  297.         int old_blk_size = band->blk_size;
  298.         /* skip header size
  299.          * If header size is not given, header size is 4 bytes. */
  300.         if (get_bits1(&ctx->gb))
  301.             skip_bits(&ctx->gb, 16);
  302.  
  303.         band->is_halfpel = get_bits(&ctx->gb, 2);
  304.         if (band->is_halfpel >= 2) {
  305.             av_log(avctx, AV_LOG_ERROR, "Invalid/unsupported mv resolution: %d!\n",
  306.                    band->is_halfpel);
  307.             return AVERROR_INVALIDDATA;
  308.         }
  309. #if IVI4_STREAM_ANALYSER
  310.         if (!band->is_halfpel)
  311.             ctx->uses_fullpel = 1;
  312. #endif
  313.  
  314.         band->checksum_present = get_bits1(&ctx->gb);
  315.         if (band->checksum_present)
  316.             band->checksum = get_bits(&ctx->gb, 16);
  317.  
  318.         indx = get_bits(&ctx->gb, 2);
  319.         if (indx == 3) {
  320.             av_log(avctx, AV_LOG_ERROR, "Invalid block size!\n");
  321.             return AVERROR_INVALIDDATA;
  322.         }
  323.         band->mb_size  = 16 >> indx;
  324.         band->blk_size = 8 >> (indx >> 1);
  325.  
  326.         band->inherit_mv     = get_bits1(&ctx->gb);
  327.         band->inherit_qdelta = get_bits1(&ctx->gb);
  328.  
  329.         band->glob_quant = get_bits(&ctx->gb, 5);
  330.  
  331.         if (!get_bits1(&ctx->gb) || ctx->frame_type == FRAMETYPE_INTRA) {
  332.             transform_id = get_bits(&ctx->gb, 5);
  333.             if (transform_id >= FF_ARRAY_ELEMS(transforms) ||
  334.                 !transforms[transform_id].inv_trans) {
  335.                 avpriv_request_sample(avctx, "Transform %d", transform_id);
  336.                 return AVERROR_PATCHWELCOME;
  337.             }
  338.             if ((transform_id >= 7 && transform_id <= 9) ||
  339.                  transform_id == 17) {
  340.                 avpriv_request_sample(avctx, "DCT transform");
  341.                 return AVERROR_PATCHWELCOME;
  342.             }
  343.  
  344.             if (transform_id < 10 && band->blk_size < 8) {
  345.                 av_log(avctx, AV_LOG_ERROR, "wrong transform size!\n");
  346.                 return AVERROR_INVALIDDATA;
  347.             }
  348. #if IVI4_STREAM_ANALYSER
  349.             if ((transform_id >= 0 && transform_id <= 2) || transform_id == 10)
  350.                 ctx->uses_haar = 1;
  351. #endif
  352.  
  353.             band->inv_transform = transforms[transform_id].inv_trans;
  354.             band->dc_transform  = transforms[transform_id].dc_trans;
  355.             band->is_2d_trans   = transforms[transform_id].is_2d_trans;
  356.  
  357.             if (transform_id < 10)
  358.                 band->transform_size = 8;
  359.             else
  360.                 band->transform_size = 4;
  361.  
  362.             if (band->blk_size != band->transform_size) {
  363.                 av_log(avctx, AV_LOG_ERROR, "transform and block size mismatch (%d != %d)\n", band->transform_size, band->blk_size);
  364.                 return AVERROR_INVALIDDATA;
  365.             }
  366.  
  367.             scan_indx = get_bits(&ctx->gb, 4);
  368.             if (scan_indx == 15) {
  369.                 av_log(avctx, AV_LOG_ERROR, "Custom scan pattern encountered!\n");
  370.                 return AVERROR_INVALIDDATA;
  371.             }
  372.             if (scan_indx > 4 && scan_indx < 10) {
  373.                 if (band->blk_size != 4) {
  374.                     av_log(avctx, AV_LOG_ERROR, "mismatching scan table!\n");
  375.                     return AVERROR_INVALIDDATA;
  376.                 }
  377.             } else if (band->blk_size != 8) {
  378.                 av_log(avctx, AV_LOG_ERROR, "mismatching scan table!\n");
  379.                 return AVERROR_INVALIDDATA;
  380.             }
  381.  
  382.             band->scan = scan_index_to_tab[scan_indx];
  383.             band->scan_size = band->blk_size;
  384.  
  385.             band->quant_mat = get_bits(&ctx->gb, 5);
  386.             if (band->quant_mat >= FF_ARRAY_ELEMS(quant_index_to_tab)) {
  387.  
  388.                 if (band->quant_mat == 31)
  389.                     av_log(avctx, AV_LOG_ERROR,
  390.                            "Custom quant matrix encountered!\n");
  391.                 else
  392.                     avpriv_request_sample(avctx, "Quantization matrix %d",
  393.                                           band->quant_mat);
  394.                 band->quant_mat = -1;
  395.                 return AVERROR_INVALIDDATA;
  396.             }
  397.         } else {
  398.             if (old_blk_size != band->blk_size) {
  399.                 av_log(avctx, AV_LOG_ERROR,
  400.                        "The band block size does not match the configuration "
  401.                        "inherited\n");
  402.                 return AVERROR_INVALIDDATA;
  403.             }
  404.             if (band->quant_mat < 0) {
  405.                 av_log(avctx, AV_LOG_ERROR, "Invalid quant_mat inherited\n");
  406.                 return AVERROR_INVALIDDATA;
  407.             }
  408.         }
  409.         if (quant_index_to_tab[band->quant_mat] > 4 && band->blk_size == 4) {
  410.             av_log(avctx, AV_LOG_ERROR, "Invalid quant matrix for 4x4 block encountered!\n");
  411.             band->quant_mat = 0;
  412.             return AVERROR_INVALIDDATA;
  413.         }
  414.         if (band->scan_size != band->blk_size) {
  415.             av_log(avctx, AV_LOG_ERROR, "mismatching scan table!\n");
  416.             return AVERROR_INVALIDDATA;
  417.         }
  418.         if (band->transform_size == 8 && band->blk_size < 8) {
  419.             av_log(avctx, AV_LOG_ERROR, "mismatching transform_size!\n");
  420.             return AVERROR_INVALIDDATA;
  421.         }
  422.  
  423.         /* decode block huffman codebook */
  424.         if (!get_bits1(&ctx->gb))
  425.             band->blk_vlc.tab = ctx->blk_vlc.tab;
  426.         else
  427.             if (ff_ivi_dec_huff_desc(&ctx->gb, 1, IVI_BLK_HUFF,
  428.                                      &band->blk_vlc, avctx))
  429.                 return AVERROR_INVALIDDATA;
  430.  
  431.         /* select appropriate rvmap table for this band */
  432.         band->rvmap_sel = get_bits1(&ctx->gb) ? get_bits(&ctx->gb, 3) : 8;
  433.  
  434.         /* decode rvmap probability corrections if any */
  435.         band->num_corr = 0; /* there is no corrections */
  436.         if (get_bits1(&ctx->gb)) {
  437.             band->num_corr = get_bits(&ctx->gb, 8); /* get number of correction pairs */
  438.             if (band->num_corr > 61) {
  439.                 av_log(avctx, AV_LOG_ERROR, "Too many corrections: %d\n",
  440.                        band->num_corr);
  441.                 return AVERROR_INVALIDDATA;
  442.             }
  443.  
  444.             /* read correction pairs */
  445.             for (i = 0; i < band->num_corr * 2; i++)
  446.                 band->corr[i] = get_bits(&ctx->gb, 8);
  447.         }
  448.     }
  449.  
  450.     if (band->blk_size == 8) {
  451.         band->intra_base = &ivi4_quant_8x8_intra[quant_index_to_tab[band->quant_mat]][0];
  452.         band->inter_base = &ivi4_quant_8x8_inter[quant_index_to_tab[band->quant_mat]][0];
  453.     } else {
  454.         band->intra_base = &ivi4_quant_4x4_intra[quant_index_to_tab[band->quant_mat]][0];
  455.         band->inter_base = &ivi4_quant_4x4_inter[quant_index_to_tab[band->quant_mat]][0];
  456.     }
  457.  
  458.     /* Indeo 4 doesn't use scale tables */
  459.     band->intra_scale = NULL;
  460.     band->inter_scale = NULL;
  461.  
  462.     align_get_bits(&ctx->gb);
  463.  
  464.     if (!band->scan) {
  465.         av_log(avctx, AV_LOG_ERROR, "band->scan not set\n");
  466.         return AVERROR_INVALIDDATA;
  467.     }
  468.  
  469.     return 0;
  470. }
  471.  
  472.  
  473. /**
  474.  *  Decode information (block type, cbp, quant delta, motion vector)
  475.  *  for all macroblocks in the current tile.
  476.  *
  477.  *  @param[in,out] ctx       pointer to the decoder context
  478.  *  @param[in,out] band      pointer to the band descriptor
  479.  *  @param[in,out] tile      pointer to the tile descriptor
  480.  *  @param[in]     avctx     pointer to the AVCodecContext
  481.  *  @return        result code: 0 = OK, negative number = error
  482.  */
  483. static int decode_mb_info(IVI45DecContext *ctx, IVIBandDesc *band,
  484.                           IVITile *tile, AVCodecContext *avctx)
  485. {
  486.     int         x, y, mv_x, mv_y, mv_delta, offs, mb_offset, blks_per_mb,
  487.                 mv_scale, mb_type_bits, s;
  488.     IVIMbInfo   *mb, *ref_mb;
  489.     int         row_offset = band->mb_size * band->pitch;
  490.  
  491.     mb     = tile->mbs;
  492.     ref_mb = tile->ref_mbs;
  493.     offs   = tile->ypos * band->pitch + tile->xpos;
  494.  
  495.     blks_per_mb  = band->mb_size   != band->blk_size  ? 4 : 1;
  496.     mb_type_bits = ctx->frame_type == FRAMETYPE_BIDIR ? 2 : 1;
  497.  
  498.     /* scale factor for motion vectors */
  499.     mv_scale = (ctx->planes[0].bands[0].mb_size >> 3) - (band->mb_size >> 3);
  500.     mv_x = mv_y = 0;
  501.  
  502.     if (((tile->width + band->mb_size-1)/band->mb_size) * ((tile->height + band->mb_size-1)/band->mb_size) != tile->num_MBs) {
  503.         av_log(avctx, AV_LOG_ERROR, "num_MBs mismatch %d %d %d %d\n", tile->width, tile->height, band->mb_size, tile->num_MBs);
  504.         return -1;
  505.     }
  506.  
  507.     for (y = tile->ypos; y < tile->ypos + tile->height; y += band->mb_size) {
  508.         mb_offset = offs;
  509.  
  510.         for (x = tile->xpos; x < tile->xpos + tile->width; x += band->mb_size) {
  511.             mb->xpos     = x;
  512.             mb->ypos     = y;
  513.             mb->buf_offs = mb_offset;
  514.  
  515.             if (get_bits1(&ctx->gb)) {
  516.                 if (ctx->frame_type == FRAMETYPE_INTRA) {
  517.                     av_log(avctx, AV_LOG_ERROR, "Empty macroblock in an INTRA picture!\n");
  518.                     return AVERROR_INVALIDDATA;
  519.                 }
  520.                 mb->type = 1; /* empty macroblocks are always INTER */
  521.                 mb->cbp  = 0; /* all blocks are empty */
  522.  
  523.                 mb->q_delta = 0;
  524.                 if (!band->plane && !band->band_num && ctx->in_q) {
  525.                     mb->q_delta = get_vlc2(&ctx->gb, ctx->mb_vlc.tab->table,
  526.                                            IVI_VLC_BITS, 1);
  527.                     mb->q_delta = IVI_TOSIGNED(mb->q_delta);
  528.                 }
  529.  
  530.                 mb->mv_x = mb->mv_y = 0; /* no motion vector coded */
  531.                 if (band->inherit_mv && ref_mb) {
  532.                     /* motion vector inheritance */
  533.                     if (mv_scale) {
  534.                         mb->mv_x = ivi_scale_mv(ref_mb->mv_x, mv_scale);
  535.                         mb->mv_y = ivi_scale_mv(ref_mb->mv_y, mv_scale);
  536.                     } else {
  537.                         mb->mv_x = ref_mb->mv_x;
  538.                         mb->mv_y = ref_mb->mv_y;
  539.                     }
  540.                 }
  541.             } else {
  542.                 if (band->inherit_mv) {
  543.                     /* copy mb_type from corresponding reference mb */
  544.                     if (!ref_mb) {
  545.                         av_log(avctx, AV_LOG_ERROR, "ref_mb unavailable\n");
  546.                         return AVERROR_INVALIDDATA;
  547.                     }
  548.                     mb->type = ref_mb->type;
  549.                 } else if (ctx->frame_type == FRAMETYPE_INTRA ||
  550.                            ctx->frame_type == FRAMETYPE_INTRA1) {
  551.                     mb->type = 0; /* mb_type is always INTRA for intra-frames */
  552.                 } else {
  553.                     mb->type = get_bits(&ctx->gb, mb_type_bits);
  554.                 }
  555.  
  556.                 mb->cbp = get_bits(&ctx->gb, blks_per_mb);
  557.  
  558.                 mb->q_delta = 0;
  559.                 if (band->inherit_qdelta) {
  560.                     if (ref_mb) mb->q_delta = ref_mb->q_delta;
  561.                 } else if (mb->cbp || (!band->plane && !band->band_num &&
  562.                            ctx->in_q)) {
  563.                     mb->q_delta = get_vlc2(&ctx->gb, ctx->mb_vlc.tab->table,
  564.                                            IVI_VLC_BITS, 1);
  565.                     mb->q_delta = IVI_TOSIGNED(mb->q_delta);
  566.                 }
  567.  
  568.                 if (!mb->type) {
  569.                     mb->mv_x = mb->mv_y = 0; /* there is no motion vector in intra-macroblocks */
  570.                 } else {
  571.                     if (band->inherit_mv) {
  572.                         if (ref_mb)
  573.                             /* motion vector inheritance */
  574.                             if (mv_scale) {
  575.                                 mb->mv_x = ivi_scale_mv(ref_mb->mv_x, mv_scale);
  576.                                 mb->mv_y = ivi_scale_mv(ref_mb->mv_y, mv_scale);
  577.                             } else {
  578.                                 mb->mv_x = ref_mb->mv_x;
  579.                                 mb->mv_y = ref_mb->mv_y;
  580.                             }
  581.                     } else {
  582.                         /* decode motion vector deltas */
  583.                         mv_delta = get_vlc2(&ctx->gb, ctx->mb_vlc.tab->table,
  584.                                             IVI_VLC_BITS, 1);
  585.                         mv_y += IVI_TOSIGNED(mv_delta);
  586.                         mv_delta = get_vlc2(&ctx->gb, ctx->mb_vlc.tab->table,
  587.                                             IVI_VLC_BITS, 1);
  588.                         mv_x += IVI_TOSIGNED(mv_delta);
  589.                         mb->mv_x = mv_x;
  590.                         mb->mv_y = mv_y;
  591.                     }
  592.                 }
  593.             }
  594.  
  595.             s= band->is_halfpel;
  596.             if (mb->type)
  597.             if ( x +  (mb->mv_x   >>s) +                 (y+               (mb->mv_y   >>s))*band->pitch < 0 ||
  598.                  x + ((mb->mv_x+s)>>s) + band->mb_size - 1
  599.                    + (y+band->mb_size - 1 +((mb->mv_y+s)>>s))*band->pitch > band->bufsize -1) {
  600.                 av_log(avctx, AV_LOG_ERROR, "motion vector %d %d outside reference\n", x*s + mb->mv_x, y*s + mb->mv_y);
  601.                 return AVERROR_INVALIDDATA;
  602.             }
  603.  
  604.             mb++;
  605.             if (ref_mb)
  606.                 ref_mb++;
  607.             mb_offset += band->mb_size;
  608.         }
  609.  
  610.         offs += row_offset;
  611.     }
  612.  
  613.     align_get_bits(&ctx->gb);
  614.  
  615.     return 0;
  616. }
  617.  
  618.  
  619. /**
  620.  *  Rearrange decoding and reference buffers.
  621.  *
  622.  *  @param[in,out] ctx       pointer to the decoder context
  623.  */
  624. static void switch_buffers(IVI45DecContext *ctx)
  625. {
  626.     switch (ctx->prev_frame_type) {
  627.     case FRAMETYPE_INTRA:
  628.     case FRAMETYPE_INTRA1:
  629.     case FRAMETYPE_INTER:
  630.         ctx->buf_switch ^= 1;
  631.         ctx->dst_buf     = ctx->buf_switch;
  632.         ctx->ref_buf     = ctx->buf_switch ^ 1;
  633.         break;
  634.     case FRAMETYPE_INTER_NOREF:
  635.         break;
  636.     }
  637.  
  638.     switch (ctx->frame_type) {
  639.     case FRAMETYPE_INTRA:
  640.     case FRAMETYPE_INTRA1:
  641.         ctx->buf_switch = 0;
  642.         /* FALLTHROUGH */
  643.     case FRAMETYPE_INTER:
  644.         ctx->dst_buf = ctx->buf_switch;
  645.         ctx->ref_buf = ctx->buf_switch ^ 1;
  646.         break;
  647.     case FRAMETYPE_INTER_NOREF:
  648.     case FRAMETYPE_NULL_FIRST:
  649.     case FRAMETYPE_NULL_LAST:
  650.         break;
  651.     }
  652. }
  653.  
  654.  
  655. static int is_nonnull_frame(IVI45DecContext *ctx)
  656. {
  657.     return ctx->frame_type < FRAMETYPE_NULL_FIRST;
  658. }
  659.  
  660.  
  661. static av_cold int decode_init(AVCodecContext *avctx)
  662. {
  663.     IVI45DecContext *ctx = avctx->priv_data;
  664.  
  665.     ff_ivi_init_static_vlc();
  666.  
  667.     /* copy rvmap tables in our context so we can apply changes to them */
  668.     memcpy(ctx->rvmap_tabs, ff_ivi_rvmap_tabs, sizeof(ff_ivi_rvmap_tabs));
  669.  
  670.     /* Force allocation of the internal buffers */
  671.     /* during picture header decoding.          */
  672.     ctx->pic_conf.pic_width  = 0;
  673.     ctx->pic_conf.pic_height = 0;
  674.  
  675.     avctx->pix_fmt = AV_PIX_FMT_YUV410P;
  676.  
  677.     ctx->decode_pic_hdr   = decode_pic_hdr;
  678.     ctx->decode_band_hdr  = decode_band_hdr;
  679.     ctx->decode_mb_info   = decode_mb_info;
  680.     ctx->switch_buffers   = switch_buffers;
  681.     ctx->is_nonnull_frame = is_nonnull_frame;
  682.  
  683.     return 0;
  684. }
  685.  
  686.  
  687. AVCodec ff_indeo4_decoder = {
  688.     .name           = "indeo4",
  689.     .long_name      = NULL_IF_CONFIG_SMALL("Intel Indeo Video Interactive 4"),
  690.     .type           = AVMEDIA_TYPE_VIDEO,
  691.     .id             = AV_CODEC_ID_INDEO4,
  692.     .priv_data_size = sizeof(IVI45DecContext),
  693.     .init           = decode_init,
  694.     .close          = ff_ivi_decode_close,
  695.     .decode         = ff_ivi_decode_frame,
  696.     .capabilities   = CODEC_CAP_DR1,
  697. };
  698.