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  1. /*
  2.  * DV decoder
  3.  * Copyright (c) 2002 Fabrice Bellard
  4.  * Copyright (c) 2004 Roman Shaposhnik
  5.  *
  6.  * 50 Mbps (DVCPRO50) support
  7.  * Copyright (c) 2006 Daniel Maas <dmaas@maasdigital.com>
  8.  *
  9.  * 100 Mbps (DVCPRO HD) support
  10.  * Initial code by Daniel Maas <dmaas@maasdigital.com> (funded by BBC R&D)
  11.  * Final code by Roman Shaposhnik
  12.  *
  13.  * Many thanks to Dan Dennedy <dan@dennedy.org> for providing wealth
  14.  * of DV technical info.
  15.  *
  16.  * This file is part of FFmpeg.
  17.  *
  18.  * FFmpeg is free software; you can redistribute it and/or
  19.  * modify it under the terms of the GNU Lesser General Public
  20.  * License as published by the Free Software Foundation; either
  21.  * version 2.1 of the License, or (at your option) any later version.
  22.  *
  23.  * FFmpeg is distributed in the hope that it will be useful,
  24.  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  25.  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  26.  * Lesser General Public License for more details.
  27.  *
  28.  * You should have received a copy of the GNU Lesser General Public
  29.  * License along with FFmpeg; if not, write to the Free Software
  30.  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  31.  */
  32.  
  33. /**
  34.  * @file
  35.  * DV decoder
  36.  */
  37.  
  38. #include "libavutil/avassert.h"
  39. #include "libavutil/imgutils.h"
  40. #include "libavutil/internal.h"
  41. #include "libavutil/pixdesc.h"
  42.  
  43. #include "avcodec.h"
  44. #include "dv.h"
  45. #include "dv_profile_internal.h"
  46. #include "dvdata.h"
  47. #include "get_bits.h"
  48. #include "idctdsp.h"
  49. #include "internal.h"
  50. #include "put_bits.h"
  51. #include "simple_idct.h"
  52.  
  53. typedef struct BlockInfo {
  54.     const uint32_t *factor_table;
  55.     const uint8_t *scan_table;
  56.     uint8_t pos; /* position in block */
  57.     void (*idct_put)(uint8_t *dest, int line_size, int16_t *block);
  58.     uint8_t partial_bit_count;
  59.     uint32_t partial_bit_buffer;
  60.     int shift_offset;
  61. } BlockInfo;
  62.  
  63. static const int dv_iweight_bits = 14;
  64.  
  65. static const uint16_t dv_iweight_88[64] = {
  66.     32768, 16705, 16705, 17734, 17032, 17734, 18205, 18081,
  67.     18081, 18205, 18725, 18562, 19195, 18562, 18725, 19266,
  68.     19091, 19705, 19705, 19091, 19266, 21407, 19643, 20267,
  69.     20228, 20267, 19643, 21407, 22725, 21826, 20853, 20806,
  70.     20806, 20853, 21826, 22725, 23170, 23170, 21407, 21400,
  71.     21407, 23170, 23170, 24598, 23786, 22018, 22018, 23786,
  72.     24598, 25251, 24465, 22654, 24465, 25251, 25972, 25172,
  73.     25172, 25972, 26722, 27969, 26722, 29692, 29692, 31521,
  74. };
  75. static const uint16_t dv_iweight_248[64] = {
  76.     32768, 16384, 16705, 16705, 17734, 17734, 17734, 17734,
  77.     18081, 18081, 18725, 18725, 21407, 21407, 19091, 19091,
  78.     19195, 19195, 18205, 18205, 18725, 18725, 19705, 19705,
  79.     20267, 20267, 21826, 21826, 23170, 23170, 20806, 20806,
  80.     20267, 20267, 19266, 19266, 21407, 21407, 20853, 20853,
  81.     21400, 21400, 23786, 23786, 24465, 24465, 22018, 22018,
  82.     23170, 23170, 22725, 22725, 24598, 24598, 24465, 24465,
  83.     25172, 25172, 27969, 27969, 25972, 25972, 29692, 29692
  84. };
  85.  
  86. /**
  87.  * The "inverse" DV100 weights are actually just the spec weights (zig-zagged).
  88.  */
  89. static const uint16_t dv_iweight_1080_y[64] = {
  90.     128,  16,  16,  17,  17,  17,  18,  18,
  91.      18,  18,  18,  18,  19,  18,  18,  19,
  92.      19,  19,  19,  19,  19,  42,  38,  40,
  93.      40,  40,  38,  42,  44,  43,  41,  41,
  94.      41,  41,  43,  44,  45,  45,  42,  42,
  95.      42,  45,  45,  48,  46,  43,  43,  46,
  96.      48,  49,  48,  44,  48,  49, 101,  98,
  97.      98, 101, 104, 109, 104, 116, 116, 123,
  98. };
  99. static const uint16_t dv_iweight_1080_c[64] = {
  100.     128,  16,  16,  17,  17,  17,  25,  25,
  101.      25,  25,  26,  25,  26,  25,  26,  26,
  102.      26,  27,  27,  26,  26,  42,  38,  40,
  103.      40,  40,  38,  42,  44,  43,  41,  41,
  104.      41,  41,  43,  44,  91,  91,  84,  84,
  105.      84,  91,  91,  96,  93,  86,  86,  93,
  106.      96, 197, 191, 177, 191, 197, 203, 197,
  107.     197, 203, 209, 219, 209, 232, 232, 246,
  108. };
  109. static const uint16_t dv_iweight_720_y[64] = {
  110.     128,  16,  16,  17,  17,  17,  18,  18,
  111.      18,  18,  18,  18,  19,  18,  18,  19,
  112.      19,  19,  19,  19,  19,  42,  38,  40,
  113.      40,  40,  38,  42,  44,  43,  41,  41,
  114.      41,  41,  43,  44,  68,  68,  63,  63,
  115.      63,  68,  68,  96,  92,  86,  86,  92,
  116.      96,  98,  96,  88,  96,  98, 202, 196,
  117.     196, 202, 208, 218, 208, 232, 232, 246,
  118. };
  119. static const uint16_t dv_iweight_720_c[64] = {
  120.     128,  24,  24,  26,  26,  26,  36,  36,
  121.      36,  36,  36,  36,  38,  36,  36,  38,
  122.      38,  38,  38,  38,  38,  84,  76,  80,
  123.      80,  80,  76,  84,  88,  86,  82,  82,
  124.      82,  82,  86,  88, 182, 182, 168, 168,
  125.     168, 182, 182, 192, 186, 192, 172, 186,
  126.     192, 394, 382, 354, 382, 394, 406, 394,
  127.     394, 406, 418, 438, 418, 464, 464, 492,
  128. };
  129.  
  130. static void dv_init_weight_tables(DVVideoContext *ctx, const AVDVProfile *d)
  131. {
  132.     int j, i, c, s;
  133.     uint32_t *factor1 = &ctx->idct_factor[0],
  134.              *factor2 = &ctx->idct_factor[DV_PROFILE_IS_HD(d) ? 4096 : 2816];
  135.  
  136.     if (DV_PROFILE_IS_HD(d)) {
  137.         /* quantization quanta by QNO for DV100 */
  138.         static const uint8_t dv100_qstep[16] = {
  139.             1, /* QNO = 0 and 1 both have no quantization */
  140.             1,
  141.             2, 3, 4, 5, 6, 7, 8, 16, 18, 20, 22, 24, 28, 52
  142.         };
  143.         const uint16_t *iweight1, *iweight2;
  144.  
  145.         if (d->height == 720) {
  146.             iweight1 = &dv_iweight_720_y[0];
  147.             iweight2 = &dv_iweight_720_c[0];
  148.         } else {
  149.             iweight1 = &dv_iweight_1080_y[0];
  150.             iweight2 = &dv_iweight_1080_c[0];
  151.         }
  152.         for (c = 0; c < 4; c++) {
  153.             for (s = 0; s < 16; s++) {
  154.                 for (i = 0; i < 64; i++) {
  155.                     *factor1++ = (dv100_qstep[s] << (c + 9)) * iweight1[i];
  156.                     *factor2++ = (dv100_qstep[s] << (c + 9)) * iweight2[i];
  157.                 }
  158.             }
  159.         }
  160.     } else {
  161.         static const uint8_t dv_quant_areas[4] = { 6, 21, 43, 64 };
  162.         const uint16_t *iweight1 = &dv_iweight_88[0];
  163.         for (j = 0; j < 2; j++, iweight1 = &dv_iweight_248[0]) {
  164.             for (s = 0; s < 22; s++) {
  165.                 for (i = c = 0; c < 4; c++) {
  166.                     for (; i < dv_quant_areas[c]; i++) {
  167.                         *factor1   = iweight1[i] << (ff_dv_quant_shifts[s][c] + 1);
  168.                         *factor2++ = (*factor1++) << 1;
  169.                     }
  170.                 }
  171.             }
  172.         }
  173.     }
  174. }
  175.  
  176. static av_cold int dvvideo_decode_init(AVCodecContext *avctx)
  177. {
  178.     DVVideoContext *s = avctx->priv_data;
  179.     IDCTDSPContext idsp;
  180.     int i;
  181.  
  182.     memset(&idsp,0, sizeof(idsp));
  183.     ff_idctdsp_init(&idsp, avctx);
  184.  
  185.     for (i = 0; i < 64; i++)
  186.         s->dv_zigzag[0][i] = idsp.idct_permutation[ff_zigzag_direct[i]];
  187.  
  188.     if (avctx->lowres){
  189.         for (i = 0; i < 64; i++){
  190.             int j = ff_dv_zigzag248_direct[i];
  191.             s->dv_zigzag[1][i] = idsp.idct_permutation[(j & 7) + (j & 8) * 4 + (j & 48) / 2];
  192.         }
  193.     }else
  194.         memcpy(s->dv_zigzag[1], ff_dv_zigzag248_direct, sizeof(s->dv_zigzag[1]));
  195.  
  196.     s->idct_put[0] = idsp.idct_put;
  197.     s->idct_put[1] = ff_simple_idct248_put;
  198.  
  199.     return ff_dvvideo_init(avctx);
  200. }
  201.  
  202. /* decode AC coefficients */
  203. static void dv_decode_ac(GetBitContext *gb, BlockInfo *mb, int16_t *block)
  204. {
  205.     int last_index = gb->size_in_bits;
  206.     const uint8_t  *scan_table   = mb->scan_table;
  207.     const uint32_t *factor_table = mb->factor_table;
  208.     int pos                      = mb->pos;
  209.     int partial_bit_count        = mb->partial_bit_count;
  210.     int level, run, vlc_len, index;
  211.  
  212.     OPEN_READER_NOSIZE(re, gb);
  213.     UPDATE_CACHE(re, gb);
  214.  
  215.     /* if we must parse a partial VLC, we do it here */
  216.     if (partial_bit_count > 0) {
  217.         re_cache              = re_cache >> partial_bit_count |
  218.                                 mb->partial_bit_buffer;
  219.         re_index             -= partial_bit_count;
  220.         mb->partial_bit_count = 0;
  221.     }
  222.  
  223.     /* get the AC coefficients until last_index is reached */
  224.     for (;;) {
  225.         ff_dlog(NULL, "%2d: bits=%04x index=%d\n", pos, SHOW_UBITS(re, gb, 16),
  226.                 re_index);
  227.         /* our own optimized GET_RL_VLC */
  228.         index   = NEG_USR32(re_cache, TEX_VLC_BITS);
  229.         vlc_len = ff_dv_rl_vlc[index].len;
  230.         if (vlc_len < 0) {
  231.             index = NEG_USR32((unsigned) re_cache << TEX_VLC_BITS, -vlc_len) +
  232.                     ff_dv_rl_vlc[index].level;
  233.             vlc_len = TEX_VLC_BITS - vlc_len;
  234.         }
  235.         level = ff_dv_rl_vlc[index].level;
  236.         run   = ff_dv_rl_vlc[index].run;
  237.  
  238.         /* gotta check if we're still within gb boundaries */
  239.         if (re_index + vlc_len > last_index) {
  240.             /* should be < 16 bits otherwise a codeword could have been parsed */
  241.             mb->partial_bit_count  = last_index - re_index;
  242.             mb->partial_bit_buffer = re_cache & ~(-1u >> mb->partial_bit_count);
  243.             re_index               = last_index;
  244.             break;
  245.         }
  246.         re_index += vlc_len;
  247.  
  248.         ff_dlog(NULL, "run=%d level=%d\n", run, level);
  249.         pos += run;
  250.         if (pos >= 64)
  251.             break;
  252.  
  253.         level = (level * factor_table[pos] + (1 << (dv_iweight_bits - 1))) >>
  254.                 dv_iweight_bits;
  255.         block[scan_table[pos]] = level;
  256.  
  257.         UPDATE_CACHE(re, gb);
  258.     }
  259.     CLOSE_READER(re, gb);
  260.     mb->pos = pos;
  261. }
  262.  
  263. static inline void bit_copy(PutBitContext *pb, GetBitContext *gb)
  264. {
  265.     int bits_left = get_bits_left(gb);
  266.     while (bits_left >= MIN_CACHE_BITS) {
  267.         put_bits(pb, MIN_CACHE_BITS, get_bits(gb, MIN_CACHE_BITS));
  268.         bits_left -= MIN_CACHE_BITS;
  269.     }
  270.     if (bits_left > 0)
  271.         put_bits(pb, bits_left, get_bits(gb, bits_left));
  272. }
  273.  
  274. /* mb_x and mb_y are in units of 8 pixels */
  275. static int dv_decode_video_segment(AVCodecContext *avctx, void *arg)
  276. {
  277.     DVVideoContext *s = avctx->priv_data;
  278.     DVwork_chunk *work_chunk = arg;
  279.     int quant, dc, dct_mode, class1, j;
  280.     int mb_index, mb_x, mb_y, last_index;
  281.     int y_stride, linesize;
  282.     int16_t *block, *block1;
  283.     int c_offset;
  284.     uint8_t *y_ptr;
  285.     const uint8_t *buf_ptr;
  286.     PutBitContext pb, vs_pb;
  287.     GetBitContext gb;
  288.     BlockInfo mb_data[5 * DV_MAX_BPM], *mb, *mb1;
  289.     LOCAL_ALIGNED_16(int16_t, sblock, [5 * DV_MAX_BPM], [64]);
  290.     LOCAL_ALIGNED_16(uint8_t, mb_bit_buffer, [80     + AV_INPUT_BUFFER_PADDING_SIZE]); /* allow some slack */
  291.     LOCAL_ALIGNED_16(uint8_t, vs_bit_buffer, [80 * 5 + AV_INPUT_BUFFER_PADDING_SIZE]); /* allow some slack */
  292.     const int log2_blocksize = 3-s->avctx->lowres;
  293.     int is_field_mode[5];
  294.     int vs_bit_buffer_damaged = 0;
  295.     int mb_bit_buffer_damaged[5] = {0};
  296.     int retried = 0;
  297.     int sta;
  298.  
  299.     av_assert1((((int) mb_bit_buffer) & 7) == 0);
  300.     av_assert1((((int) vs_bit_buffer) & 7) == 0);
  301.  
  302. retry:
  303.  
  304.     memset(sblock, 0, 5 * DV_MAX_BPM * sizeof(*sblock));
  305.  
  306.     /* pass 1: read DC and AC coefficients in blocks */
  307.     buf_ptr = &s->buf[work_chunk->buf_offset * 80];
  308.     block1  = &sblock[0][0];
  309.     mb1     = mb_data;
  310.     init_put_bits(&vs_pb, vs_bit_buffer, 5 * 80);
  311.     for (mb_index = 0; mb_index < 5; mb_index++, mb1 += s->sys->bpm, block1 += s->sys->bpm * 64) {
  312.         /* skip header */
  313.         quant    = buf_ptr[3] & 0x0f;
  314.         if (avctx->error_concealment) {
  315.             if ((buf_ptr[3] >> 4) == 0x0E)
  316.                 vs_bit_buffer_damaged = 1;
  317.             if (!mb_index) {
  318.                 sta = buf_ptr[3] >> 4;
  319.             } else if (sta != (buf_ptr[3] >> 4))
  320.                 vs_bit_buffer_damaged = 1;
  321.         }
  322.         buf_ptr += 4;
  323.         init_put_bits(&pb, mb_bit_buffer, 80);
  324.         mb    = mb1;
  325.         block = block1;
  326.         is_field_mode[mb_index] = 0;
  327.         for (j = 0; j < s->sys->bpm; j++) {
  328.             last_index = s->sys->block_sizes[j];
  329.             init_get_bits(&gb, buf_ptr, last_index);
  330.  
  331.             /* get the DC */
  332.             dc       = get_sbits(&gb, 9);
  333.             dct_mode = get_bits1(&gb);
  334.             class1   = get_bits(&gb, 2);
  335.             if (DV_PROFILE_IS_HD(s->sys)) {
  336.                 mb->idct_put     = s->idct_put[0];
  337.                 mb->scan_table   = s->dv_zigzag[0];
  338.                 mb->factor_table = &s->idct_factor[(j >= 4) * 4 * 16 * 64 +
  339.                                                    class1       * 16 * 64 +
  340.                                                    quant             * 64];
  341.                 is_field_mode[mb_index] |= !j && dct_mode;
  342.             } else {
  343.                 mb->idct_put     = s->idct_put[dct_mode && log2_blocksize == 3];
  344.                 mb->scan_table   = s->dv_zigzag[dct_mode];
  345.                 mb->factor_table =
  346.                     &s->idct_factor[(class1 == 3)               * 2 * 22 * 64 +
  347.                                     dct_mode                        * 22 * 64 +
  348.                                     (quant + ff_dv_quant_offset[class1]) * 64];
  349.             }
  350.             dc = dc * 4;
  351.             /* convert to unsigned because 128 is not added in the
  352.              * standard IDCT */
  353.             dc                   += 1024;
  354.             block[0]              = dc;
  355.             buf_ptr              += last_index >> 3;
  356.             mb->pos               = 0;
  357.             mb->partial_bit_count = 0;
  358.  
  359.             ff_dlog(avctx, "MB block: %d, %d ", mb_index, j);
  360.             dv_decode_ac(&gb, mb, block);
  361.  
  362.             /* write the remaining bits in a new buffer only if the
  363.              * block is finished */
  364.             if (mb->pos >= 64)
  365.                 bit_copy(&pb, &gb);
  366.             if (mb->pos >= 64 && mb->pos < 127)
  367.                 vs_bit_buffer_damaged = mb_bit_buffer_damaged[mb_index] = 1;
  368.  
  369.             block += 64;
  370.             mb++;
  371.         }
  372.  
  373.         if (mb_bit_buffer_damaged[mb_index] > 0)
  374.             continue;
  375.  
  376.         /* pass 2: we can do it just after */
  377.         ff_dlog(avctx, "***pass 2 size=%d MB#=%d\n", put_bits_count(&pb), mb_index);
  378.         block = block1;
  379.         mb    = mb1;
  380.         init_get_bits(&gb, mb_bit_buffer, put_bits_count(&pb));
  381.         put_bits32(&pb, 0); // padding must be zeroed
  382.         flush_put_bits(&pb);
  383.         for (j = 0; j < s->sys->bpm; j++, block += 64, mb++) {
  384.             if (mb->pos < 64 && get_bits_left(&gb) > 0) {
  385.                 dv_decode_ac(&gb, mb, block);
  386.                 /* if still not finished, no need to parse other blocks */
  387.                 if (mb->pos < 64)
  388.                     break;
  389.                 if (mb->pos < 127)
  390.                     vs_bit_buffer_damaged = mb_bit_buffer_damaged[mb_index] = 1;
  391.             }
  392.         }
  393.         /* all blocks are finished, so the extra bytes can be used at
  394.          * the video segment level */
  395.         if (j >= s->sys->bpm)
  396.             bit_copy(&vs_pb, &gb);
  397.     }
  398.  
  399.     /* we need a pass over the whole video segment */
  400.     ff_dlog(avctx, "***pass 3 size=%d\n", put_bits_count(&vs_pb));
  401.     block = &sblock[0][0];
  402.     mb    = mb_data;
  403.     init_get_bits(&gb, vs_bit_buffer, put_bits_count(&vs_pb));
  404.     put_bits32(&vs_pb, 0); // padding must be zeroed
  405.     flush_put_bits(&vs_pb);
  406.     for (mb_index = 0; mb_index < 5; mb_index++) {
  407.         for (j = 0; j < s->sys->bpm; j++) {
  408.             if (mb->pos < 64 && get_bits_left(&gb) > 0 && !vs_bit_buffer_damaged) {
  409.                 ff_dlog(avctx, "start %d:%d\n", mb_index, j);
  410.                 dv_decode_ac(&gb, mb, block);
  411.             }
  412.  
  413.             if (mb->pos >= 64 && mb->pos < 127) {
  414.                 av_log(avctx, AV_LOG_ERROR,
  415.                        "AC EOB marker is absent pos=%d\n", mb->pos);
  416.                 vs_bit_buffer_damaged = 1;
  417.             }
  418.             block += 64;
  419.             mb++;
  420.         }
  421.     }
  422.     if (vs_bit_buffer_damaged && !retried) {
  423.         av_log(avctx, AV_LOG_ERROR, "Concealing bitstream errors\n");
  424.         retried = 1;
  425.         goto retry;
  426.     }
  427.  
  428.     /* compute idct and place blocks */
  429.     block = &sblock[0][0];
  430.     mb    = mb_data;
  431.     for (mb_index = 0; mb_index < 5; mb_index++) {
  432.         dv_calculate_mb_xy(s, work_chunk, mb_index, &mb_x, &mb_y);
  433.  
  434.         /* idct_put'ting luminance */
  435.         if ((s->sys->pix_fmt == AV_PIX_FMT_YUV420P)                      ||
  436.             (s->sys->pix_fmt == AV_PIX_FMT_YUV411P && mb_x >= (704 / 8)) ||
  437.             (s->sys->height >= 720 && mb_y != 134)) {
  438.             y_stride = (s->frame->linesize[0] <<
  439.                         ((!is_field_mode[mb_index]) * log2_blocksize));
  440.         } else {
  441.             y_stride = (2 << log2_blocksize);
  442.         }
  443.         y_ptr    = s->frame->data[0] +
  444.                    ((mb_y * s->frame->linesize[0] + mb_x) << log2_blocksize);
  445.         linesize = s->frame->linesize[0] << is_field_mode[mb_index];
  446.         mb[0].idct_put(y_ptr, linesize, block + 0 * 64);
  447.         if (s->sys->video_stype == 4) { /* SD 422 */
  448.             mb[2].idct_put(y_ptr + (1 << log2_blocksize),            linesize, block + 2 * 64);
  449.         } else {
  450.             mb[1].idct_put(y_ptr + (1 << log2_blocksize),            linesize, block + 1 * 64);
  451.             mb[2].idct_put(y_ptr                         + y_stride, linesize, block + 2 * 64);
  452.             mb[3].idct_put(y_ptr + (1 << log2_blocksize) + y_stride, linesize, block + 3 * 64);
  453.         }
  454.         mb    += 4;
  455.         block += 4 * 64;
  456.  
  457.         /* idct_put'ting chrominance */
  458.         c_offset = (((mb_y >>  (s->sys->pix_fmt == AV_PIX_FMT_YUV420P)) * s->frame->linesize[1] +
  459.                      (mb_x >> ((s->sys->pix_fmt == AV_PIX_FMT_YUV411P) ? 2 : 1))) << log2_blocksize);
  460.         for (j = 2; j; j--) {
  461.             uint8_t *c_ptr = s->frame->data[j] + c_offset;
  462.             if (s->sys->pix_fmt == AV_PIX_FMT_YUV411P && mb_x >= (704 / 8)) {
  463.                 uint64_t aligned_pixels[64 / 8];
  464.                 uint8_t *pixels = (uint8_t *) aligned_pixels;
  465.                 uint8_t *c_ptr1, *ptr1;
  466.                 int x, y;
  467.                 mb->idct_put(pixels, 8, block);
  468.                 for (y = 0; y < (1 << log2_blocksize); y++, c_ptr += s->frame->linesize[j], pixels += 8) {
  469.                     ptr1   = pixels + ((1 << (log2_blocksize))>>1);
  470.                     c_ptr1 = c_ptr + (s->frame->linesize[j] << log2_blocksize);
  471.                     for (x = 0; x < (1 << FFMAX(log2_blocksize - 1, 0)); x++) {
  472.                         c_ptr[x]  = pixels[x];
  473.                         c_ptr1[x] = ptr1[x];
  474.                     }
  475.                 }
  476.                 block += 64;
  477.                 mb++;
  478.             } else {
  479.                 y_stride = (mb_y == 134) ? (1 << log2_blocksize) :
  480.                            s->frame->linesize[j] << ((!is_field_mode[mb_index]) * log2_blocksize);
  481.                 linesize = s->frame->linesize[j] << is_field_mode[mb_index];
  482.                 (mb++)->idct_put(c_ptr, linesize, block);
  483.                 block += 64;
  484.                 if (s->sys->bpm == 8) {
  485.                     (mb++)->idct_put(c_ptr + y_stride, linesize, block);
  486.                     block += 64;
  487.                 }
  488.             }
  489.         }
  490.     }
  491.     return 0;
  492. }
  493.  
  494. /* NOTE: exactly one frame must be given (120000 bytes for NTSC,
  495.  * 144000 bytes for PAL - or twice those for 50Mbps) */
  496. static int dvvideo_decode_frame(AVCodecContext *avctx, void *data,
  497.                                 int *got_frame, AVPacket *avpkt)
  498. {
  499.     uint8_t *buf = avpkt->data;
  500.     int buf_size = avpkt->size;
  501.     DVVideoContext *s = avctx->priv_data;
  502.     const uint8_t *vsc_pack;
  503.     int apt, is16_9, ret;
  504.     const AVDVProfile *sys;
  505.  
  506.     sys = ff_dv_frame_profile(avctx, s->sys, buf, buf_size);
  507.     if (!sys || buf_size < sys->frame_size) {
  508.         av_log(avctx, AV_LOG_ERROR, "could not find dv frame profile\n");
  509.         return -1; /* NOTE: we only accept several full frames */
  510.     }
  511.  
  512.     if (sys != s->sys) {
  513.         ret = ff_dv_init_dynamic_tables(s, sys);
  514.         if (ret < 0) {
  515.             av_log(avctx, AV_LOG_ERROR, "Error initializing the work tables.\n");
  516.             return ret;
  517.         }
  518.         dv_init_weight_tables(s, sys);
  519.         s->sys = sys;
  520.     }
  521.  
  522.     s->frame            = data;
  523.     s->frame->key_frame = 1;
  524.     s->frame->pict_type = AV_PICTURE_TYPE_I;
  525.     avctx->pix_fmt      = s->sys->pix_fmt;
  526.     avctx->framerate    = av_inv_q(s->sys->time_base);
  527.  
  528.     ret = ff_set_dimensions(avctx, s->sys->width, s->sys->height);
  529.     if (ret < 0)
  530.         return ret;
  531.  
  532.     /* Determine the codec's sample_aspect ratio from the packet */
  533.     vsc_pack = buf + 80 * 5 + 48 + 5;
  534.     if (*vsc_pack == dv_video_control) {
  535.         apt    = buf[4] & 0x07;
  536.         is16_9 = (vsc_pack[2] & 0x07) == 0x02 ||
  537.                  (!apt && (vsc_pack[2] & 0x07) == 0x07);
  538.         ff_set_sar(avctx, s->sys->sar[is16_9]);
  539.     }
  540.  
  541.     if ((ret = ff_get_buffer(avctx, s->frame, 0)) < 0)
  542.         return ret;
  543.     s->frame->interlaced_frame = 1;
  544.     s->frame->top_field_first  = 0;
  545.  
  546.     /* Determine the codec's field order from the packet */
  547.     if ( *vsc_pack == dv_video_control ) {
  548.         s->frame->top_field_first = !(vsc_pack[3] & 0x40);
  549.     }
  550.  
  551.     s->buf = buf;
  552.     avctx->execute(avctx, dv_decode_video_segment, s->work_chunks, NULL,
  553.                    dv_work_pool_size(s->sys), sizeof(DVwork_chunk));
  554.  
  555.     emms_c();
  556.  
  557.     /* return image */
  558.     *got_frame = 1;
  559.  
  560.     return s->sys->frame_size;
  561. }
  562.  
  563. AVCodec ff_dvvideo_decoder = {
  564.     .name           = "dvvideo",
  565.     .long_name      = NULL_IF_CONFIG_SMALL("DV (Digital Video)"),
  566.     .type           = AVMEDIA_TYPE_VIDEO,
  567.     .id             = AV_CODEC_ID_DVVIDEO,
  568.     .priv_data_size = sizeof(DVVideoContext),
  569.     .init           = dvvideo_decode_init,
  570.     .decode         = dvvideo_decode_frame,
  571.     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_SLICE_THREADS,
  572.     .max_lowres     = 3,
  573. };
  574.