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  1. /*
  2.  * H.263 decoder
  3.  * Copyright (c) 2001 Fabrice Bellard
  4.  * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
  5.  *
  6.  * This file is part of FFmpeg.
  7.  *
  8.  * FFmpeg is free software; you can redistribute it and/or
  9.  * modify it under the terms of the GNU Lesser General Public
  10.  * License as published by the Free Software Foundation; either
  11.  * version 2.1 of the License, or (at your option) any later version.
  12.  *
  13.  * FFmpeg is distributed in the hope that it will be useful,
  14.  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15.  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16.  * Lesser General Public License for more details.
  17.  *
  18.  * You should have received a copy of the GNU Lesser General Public
  19.  * License along with FFmpeg; if not, write to the Free Software
  20.  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21.  */
  22.  
  23. /**
  24.  * @file
  25.  * H.263 decoder.
  26.  */
  27.  
  28. #define UNCHECKED_BITSTREAM_READER 1
  29.  
  30. #include "libavutil/cpu.h"
  31. #include "avcodec.h"
  32. #include "error_resilience.h"
  33. #include "flv.h"
  34. #include "h263.h"
  35. #include "h263_parser.h"
  36. #include "internal.h"
  37. #include "mpeg_er.h"
  38. #include "mpeg4video.h"
  39. #include "mpeg4video_parser.h"
  40. #include "mpegutils.h"
  41. #include "mpegvideo.h"
  42. #include "msmpeg4.h"
  43. #include "qpeldsp.h"
  44. #include "vdpau_compat.h"
  45. #include "thread.h"
  46. #include "wmv2.h"
  47.  
  48. static enum AVPixelFormat h263_get_format(AVCodecContext *avctx)
  49. {
  50.     if (avctx->codec->id == AV_CODEC_ID_MSS2)
  51.         return AV_PIX_FMT_YUV420P;
  52.  
  53.     if (CONFIG_GRAY && (avctx->flags & AV_CODEC_FLAG_GRAY)) {
  54.         if (avctx->color_range == AVCOL_RANGE_UNSPECIFIED)
  55.             avctx->color_range = AVCOL_RANGE_MPEG;
  56.         return AV_PIX_FMT_GRAY8;
  57.     }
  58.  
  59.     return avctx->pix_fmt = ff_get_format(avctx, avctx->codec->pix_fmts);
  60. }
  61.  
  62. av_cold int ff_h263_decode_init(AVCodecContext *avctx)
  63. {
  64.     MpegEncContext *s = avctx->priv_data;
  65.     int ret;
  66.  
  67.     s->out_format      = FMT_H263;
  68.  
  69.     // set defaults
  70.     ff_mpv_decode_defaults(s);
  71.     ff_mpv_decode_init(s, avctx);
  72.  
  73.     s->quant_precision = 5;
  74.     s->decode_mb       = ff_h263_decode_mb;
  75.     s->low_delay       = 1;
  76.     s->unrestricted_mv = 1;
  77.  
  78.     /* select sub codec */
  79.     switch (avctx->codec->id) {
  80.     case AV_CODEC_ID_H263:
  81.     case AV_CODEC_ID_H263P:
  82.         s->unrestricted_mv = 0;
  83.         avctx->chroma_sample_location = AVCHROMA_LOC_CENTER;
  84.         break;
  85.     case AV_CODEC_ID_MPEG4:
  86.         break;
  87.     case AV_CODEC_ID_MSMPEG4V1:
  88.         s->h263_pred       = 1;
  89.         s->msmpeg4_version = 1;
  90.         break;
  91.     case AV_CODEC_ID_MSMPEG4V2:
  92.         s->h263_pred       = 1;
  93.         s->msmpeg4_version = 2;
  94.         break;
  95.     case AV_CODEC_ID_MSMPEG4V3:
  96.         s->h263_pred       = 1;
  97.         s->msmpeg4_version = 3;
  98.         break;
  99.     case AV_CODEC_ID_WMV1:
  100.         s->h263_pred       = 1;
  101.         s->msmpeg4_version = 4;
  102.         break;
  103.     case AV_CODEC_ID_WMV2:
  104.         s->h263_pred       = 1;
  105.         s->msmpeg4_version = 5;
  106.         break;
  107.     case AV_CODEC_ID_VC1:
  108.     case AV_CODEC_ID_WMV3:
  109.     case AV_CODEC_ID_VC1IMAGE:
  110.     case AV_CODEC_ID_WMV3IMAGE:
  111.     case AV_CODEC_ID_MSS2:
  112.         s->h263_pred       = 1;
  113.         s->msmpeg4_version = 6;
  114.         avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
  115.         break;
  116.     case AV_CODEC_ID_H263I:
  117.         break;
  118.     case AV_CODEC_ID_FLV1:
  119.         s->h263_flv = 1;
  120.         break;
  121.     default:
  122.         av_log(avctx, AV_LOG_ERROR, "Unsupported codec %d\n",
  123.                avctx->codec->id);
  124.         return AVERROR(ENOSYS);
  125.     }
  126.     s->codec_id    = avctx->codec->id;
  127.  
  128.     if (avctx->codec_tag == AV_RL32("L263") || avctx->codec_tag == AV_RL32("S263"))
  129.         if (avctx->extradata_size == 56 && avctx->extradata[0] == 1)
  130.             s->ehc_mode = 1;
  131.  
  132.     /* for h263, we allocate the images after having read the header */
  133.     if (avctx->codec->id != AV_CODEC_ID_H263 &&
  134.         avctx->codec->id != AV_CODEC_ID_H263P &&
  135.         avctx->codec->id != AV_CODEC_ID_MPEG4) {
  136.         avctx->pix_fmt = h263_get_format(avctx);
  137.         ff_mpv_idct_init(s);
  138.         if ((ret = ff_mpv_common_init(s)) < 0)
  139.             return ret;
  140.     }
  141.  
  142.     ff_h263dsp_init(&s->h263dsp);
  143.     ff_qpeldsp_init(&s->qdsp);
  144.     ff_h263_decode_init_vlc();
  145.  
  146.     return 0;
  147. }
  148.  
  149. av_cold int ff_h263_decode_end(AVCodecContext *avctx)
  150. {
  151.     MpegEncContext *s = avctx->priv_data;
  152.  
  153.     ff_mpv_common_end(s);
  154.     return 0;
  155. }
  156.  
  157. /**
  158.  * Return the number of bytes consumed for building the current frame.
  159.  */
  160. static int get_consumed_bytes(MpegEncContext *s, int buf_size)
  161. {
  162.     int pos = (get_bits_count(&s->gb) + 7) >> 3;
  163.  
  164.     if (s->divx_packed || s->avctx->hwaccel) {
  165.         /* We would have to scan through the whole buf to handle the weird
  166.          * reordering ... */
  167.         return buf_size;
  168.     } else if (s->avctx->flags & AV_CODEC_FLAG_TRUNCATED) {
  169.         pos -= s->parse_context.last_index;
  170.         // padding is not really read so this might be -1
  171.         if (pos < 0)
  172.             pos = 0;
  173.         return pos;
  174.     } else {
  175.         // avoid infinite loops (maybe not needed...)
  176.         if (pos == 0)
  177.             pos = 1;
  178.         // oops ;)
  179.         if (pos + 10 > buf_size)
  180.             pos = buf_size;
  181.  
  182.         return pos;
  183.     }
  184. }
  185.  
  186. static int decode_slice(MpegEncContext *s)
  187. {
  188.     const int part_mask = s->partitioned_frame
  189.                           ? (ER_AC_END | ER_AC_ERROR) : 0x7F;
  190.     const int mb_size   = 16 >> s->avctx->lowres;
  191.     int ret;
  192.  
  193.     s->last_resync_gb   = s->gb;
  194.     s->first_slice_line = 1;
  195.     s->resync_mb_x      = s->mb_x;
  196.     s->resync_mb_y      = s->mb_y;
  197.  
  198.     ff_set_qscale(s, s->qscale);
  199.  
  200.     if (s->avctx->hwaccel) {
  201.         const uint8_t *start = s->gb.buffer + get_bits_count(&s->gb) / 8;
  202.         ret = s->avctx->hwaccel->decode_slice(s->avctx, start, s->gb.buffer_end - start);
  203.         // ensure we exit decode loop
  204.         s->mb_y = s->mb_height;
  205.         return ret;
  206.     }
  207.  
  208.     if (s->partitioned_frame) {
  209.         const int qscale = s->qscale;
  210.  
  211.         if (CONFIG_MPEG4_DECODER && s->codec_id == AV_CODEC_ID_MPEG4)
  212.             if ((ret = ff_mpeg4_decode_partitions(s->avctx->priv_data)) < 0)
  213.                 return ret;
  214.  
  215.         /* restore variables which were modified */
  216.         s->first_slice_line = 1;
  217.         s->mb_x             = s->resync_mb_x;
  218.         s->mb_y             = s->resync_mb_y;
  219.         ff_set_qscale(s, qscale);
  220.     }
  221.  
  222.     for (; s->mb_y < s->mb_height; s->mb_y++) {
  223.         /* per-row end of slice checks */
  224.         if (s->msmpeg4_version) {
  225.             if (s->resync_mb_y + s->slice_height == s->mb_y) {
  226.                 ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
  227.                                 s->mb_x - 1, s->mb_y, ER_MB_END);
  228.  
  229.                 return 0;
  230.             }
  231.         }
  232.  
  233.         if (s->msmpeg4_version == 1) {
  234.             s->last_dc[0] =
  235.             s->last_dc[1] =
  236.             s->last_dc[2] = 128;
  237.         }
  238.  
  239.         ff_init_block_index(s);
  240.         for (; s->mb_x < s->mb_width; s->mb_x++) {
  241.             int ret;
  242.  
  243.             ff_update_block_index(s);
  244.  
  245.             if (s->resync_mb_x == s->mb_x && s->resync_mb_y + 1 == s->mb_y)
  246.                 s->first_slice_line = 0;
  247.  
  248.             /* DCT & quantize */
  249.  
  250.             s->mv_dir  = MV_DIR_FORWARD;
  251.             s->mv_type = MV_TYPE_16X16;
  252.             ff_dlog(s, "%d %d %06X\n",
  253.                     ret, get_bits_count(&s->gb), show_bits(&s->gb, 24));
  254.  
  255.             ff_tlog(NULL, "Decoding MB at %dx%d\n", s->mb_x, s->mb_y);
  256.             ret = s->decode_mb(s, s->block);
  257.  
  258.             if (s->pict_type != AV_PICTURE_TYPE_B)
  259.                 ff_h263_update_motion_val(s);
  260.  
  261.             if (ret < 0) {
  262.                 const int xy = s->mb_x + s->mb_y * s->mb_stride;
  263.                 if (ret == SLICE_END) {
  264.                     ff_mpv_decode_mb(s, s->block);
  265.                     if (s->loop_filter)
  266.                         ff_h263_loop_filter(s);
  267.  
  268.                     ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
  269.                                     s->mb_x, s->mb_y, ER_MB_END & part_mask);
  270.  
  271.                     s->padding_bug_score--;
  272.  
  273.                     if (++s->mb_x >= s->mb_width) {
  274.                         s->mb_x = 0;
  275.                         ff_mpeg_draw_horiz_band(s, s->mb_y * mb_size, mb_size);
  276.                         ff_mpv_report_decode_progress(s);
  277.                         s->mb_y++;
  278.                     }
  279.                     return 0;
  280.                 } else if (ret == SLICE_NOEND) {
  281.                     av_log(s->avctx, AV_LOG_ERROR,
  282.                            "Slice mismatch at MB: %d\n", xy);
  283.                     ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
  284.                                     s->mb_x + 1, s->mb_y,
  285.                                     ER_MB_END & part_mask);
  286.                     return AVERROR_INVALIDDATA;
  287.                 }
  288.                 av_log(s->avctx, AV_LOG_ERROR, "Error at MB: %d\n", xy);
  289.                 ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
  290.                                 s->mb_x, s->mb_y, ER_MB_ERROR & part_mask);
  291.  
  292.                 if (s->avctx->err_recognition & AV_EF_IGNORE_ERR)
  293.                     continue;
  294.                 return AVERROR_INVALIDDATA;
  295.             }
  296.  
  297.             ff_mpv_decode_mb(s, s->block);
  298.             if (s->loop_filter)
  299.                 ff_h263_loop_filter(s);
  300.         }
  301.  
  302.         ff_mpeg_draw_horiz_band(s, s->mb_y * mb_size, mb_size);
  303.         ff_mpv_report_decode_progress(s);
  304.  
  305.         s->mb_x = 0;
  306.     }
  307.  
  308.     av_assert1(s->mb_x == 0 && s->mb_y == s->mb_height);
  309.  
  310.     if (s->codec_id == AV_CODEC_ID_MPEG4         &&
  311.         (s->workaround_bugs & FF_BUG_AUTODETECT) &&
  312.         get_bits_left(&s->gb) >= 48              &&
  313.         show_bits(&s->gb, 24) == 0x4010          &&
  314.         !s->data_partitioning)
  315.         s->padding_bug_score += 32;
  316.  
  317.     /* try to detect the padding bug */
  318.     if (s->codec_id == AV_CODEC_ID_MPEG4         &&
  319.         (s->workaround_bugs & FF_BUG_AUTODETECT) &&
  320.         get_bits_left(&s->gb) >= 0               &&
  321.         get_bits_left(&s->gb) < 137              &&
  322.         !s->data_partitioning) {
  323.         const int bits_count = get_bits_count(&s->gb);
  324.         const int bits_left  = s->gb.size_in_bits - bits_count;
  325.  
  326.         if (bits_left == 0) {
  327.             s->padding_bug_score += 16;
  328.         } else if (bits_left != 1) {
  329.             int v = show_bits(&s->gb, 8);
  330.             v |= 0x7F >> (7 - (bits_count & 7));
  331.  
  332.             if (v == 0x7F && bits_left <= 8)
  333.                 s->padding_bug_score--;
  334.             else if (v == 0x7F && ((get_bits_count(&s->gb) + 8) & 8) &&
  335.                      bits_left <= 16)
  336.                 s->padding_bug_score += 4;
  337.             else
  338.                 s->padding_bug_score++;
  339.         }
  340.     }
  341.  
  342.     if (s->codec_id == AV_CODEC_ID_H263          &&
  343.         (s->workaround_bugs & FF_BUG_AUTODETECT) &&
  344.         get_bits_left(&s->gb) >= 8               &&
  345.         get_bits_left(&s->gb) < 300              &&
  346.         s->pict_type == AV_PICTURE_TYPE_I        &&
  347.         show_bits(&s->gb, 8) == 0                &&
  348.         !s->data_partitioning) {
  349.  
  350.         s->padding_bug_score += 32;
  351.     }
  352.  
  353.     if (s->codec_id == AV_CODEC_ID_H263          &&
  354.         (s->workaround_bugs & FF_BUG_AUTODETECT) &&
  355.         get_bits_left(&s->gb) >= 64              &&
  356.         AV_RB64(s->gb.buffer_end - 8) == 0xCDCDCDCDFC7F0000) {
  357.  
  358.         s->padding_bug_score += 32;
  359.     }
  360.  
  361.     if (s->workaround_bugs & FF_BUG_AUTODETECT) {
  362.         if (
  363.             (s->padding_bug_score > -2 && !s->data_partitioning))
  364.             s->workaround_bugs |= FF_BUG_NO_PADDING;
  365.         else
  366.             s->workaround_bugs &= ~FF_BUG_NO_PADDING;
  367.     }
  368.  
  369.     // handle formats which don't have unique end markers
  370.     if (s->msmpeg4_version || (s->workaround_bugs & FF_BUG_NO_PADDING)) { // FIXME perhaps solve this more cleanly
  371.         int left      = get_bits_left(&s->gb);
  372.         int max_extra = 7;
  373.  
  374.         /* no markers in M$ crap */
  375.         if (s->msmpeg4_version && s->pict_type == AV_PICTURE_TYPE_I)
  376.             max_extra += 17;
  377.  
  378.         /* buggy padding but the frame should still end approximately at
  379.          * the bitstream end */
  380.         if ((s->workaround_bugs & FF_BUG_NO_PADDING) &&
  381.             (s->avctx->err_recognition & (AV_EF_BUFFER|AV_EF_AGGRESSIVE)))
  382.             max_extra += 48;
  383.         else if ((s->workaround_bugs & FF_BUG_NO_PADDING))
  384.             max_extra += 256 * 256 * 256 * 64;
  385.  
  386.         if (left > max_extra)
  387.             av_log(s->avctx, AV_LOG_ERROR,
  388.                    "discarding %d junk bits at end, next would be %X\n",
  389.                    left, show_bits(&s->gb, 24));
  390.         else if (left < 0)
  391.             av_log(s->avctx, AV_LOG_ERROR, "overreading %d bits\n", -left);
  392.         else
  393.             ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
  394.                             s->mb_x - 1, s->mb_y, ER_MB_END);
  395.  
  396.         return 0;
  397.     }
  398.  
  399.     av_log(s->avctx, AV_LOG_ERROR,
  400.            "slice end not reached but screenspace end (%d left %06X, score= %d)\n",
  401.            get_bits_left(&s->gb), show_bits(&s->gb, 24), s->padding_bug_score);
  402.  
  403.     ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y,
  404.                     ER_MB_END & part_mask);
  405.  
  406.     return AVERROR_INVALIDDATA;
  407. }
  408.  
  409. int ff_h263_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
  410.                          AVPacket *avpkt)
  411. {
  412.     const uint8_t *buf = avpkt->data;
  413.     int buf_size       = avpkt->size;
  414.     MpegEncContext *s  = avctx->priv_data;
  415.     int ret;
  416.     int slice_ret = 0;
  417.     AVFrame *pict = data;
  418.  
  419.     /* no supplementary picture */
  420.     if (buf_size == 0) {
  421.         /* special case for last picture */
  422.         if (s->low_delay == 0 && s->next_picture_ptr) {
  423.             if ((ret = av_frame_ref(pict, s->next_picture_ptr->f)) < 0)
  424.                 return ret;
  425.             s->next_picture_ptr = NULL;
  426.  
  427.             *got_frame = 1;
  428.         }
  429.  
  430.         return 0;
  431.     }
  432.  
  433.     if (s->avctx->flags & AV_CODEC_FLAG_TRUNCATED) {
  434.         int next;
  435.  
  436.         if (CONFIG_MPEG4_DECODER && s->codec_id == AV_CODEC_ID_MPEG4) {
  437.             next = ff_mpeg4_find_frame_end(&s->parse_context, buf, buf_size);
  438.         } else if (CONFIG_H263_DECODER && s->codec_id == AV_CODEC_ID_H263) {
  439.             next = ff_h263_find_frame_end(&s->parse_context, buf, buf_size);
  440.         } else if (CONFIG_H263P_DECODER && s->codec_id == AV_CODEC_ID_H263P) {
  441.             next = ff_h263_find_frame_end(&s->parse_context, buf, buf_size);
  442.         } else {
  443.             av_log(s->avctx, AV_LOG_ERROR,
  444.                    "this codec does not support truncated bitstreams\n");
  445.             return AVERROR(ENOSYS);
  446.         }
  447.  
  448.         if (ff_combine_frame(&s->parse_context, next, (const uint8_t **)&buf,
  449.                              &buf_size) < 0)
  450.             return buf_size;
  451.     }
  452.  
  453. retry:
  454.     if (s->divx_packed && s->bitstream_buffer_size) {
  455.         int i;
  456.         for(i=0; i < buf_size-3; i++) {
  457.             if (buf[i]==0 && buf[i+1]==0 && buf[i+2]==1) {
  458.                 if (buf[i+3]==0xB0) {
  459.                     av_log(s->avctx, AV_LOG_WARNING, "Discarding excessive bitstream in packed xvid\n");
  460.                     s->bitstream_buffer_size = 0;
  461.                 }
  462.                 break;
  463.             }
  464.         }
  465.     }
  466.  
  467.     if (s->bitstream_buffer_size && (s->divx_packed || buf_size <= MAX_NVOP_SIZE)) // divx 5.01+/xvid frame reorder
  468.         ret = init_get_bits8(&s->gb, s->bitstream_buffer,
  469.                              s->bitstream_buffer_size);
  470.     else
  471.         ret = init_get_bits8(&s->gb, buf, buf_size);
  472.  
  473.     s->bitstream_buffer_size = 0;
  474.     if (ret < 0)
  475.         return ret;
  476.  
  477.     if (!s->context_initialized)
  478.         // we need the idct permutaton for reading a custom matrix
  479.         ff_mpv_idct_init(s);
  480.  
  481.     /* let's go :-) */
  482.     if (CONFIG_WMV2_DECODER && s->msmpeg4_version == 5) {
  483.         ret = ff_wmv2_decode_picture_header(s);
  484.     } else if (CONFIG_MSMPEG4_DECODER && s->msmpeg4_version) {
  485.         ret = ff_msmpeg4_decode_picture_header(s);
  486.     } else if (CONFIG_MPEG4_DECODER && avctx->codec_id == AV_CODEC_ID_MPEG4) {
  487.         if (s->avctx->extradata_size && s->picture_number == 0) {
  488.             GetBitContext gb;
  489.  
  490.             if (init_get_bits8(&gb, s->avctx->extradata, s->avctx->extradata_size) >= 0 )
  491.                 ff_mpeg4_decode_picture_header(avctx->priv_data, &gb);
  492.         }
  493.         ret = ff_mpeg4_decode_picture_header(avctx->priv_data, &s->gb);
  494.     } else if (CONFIG_H263I_DECODER && s->codec_id == AV_CODEC_ID_H263I) {
  495.         ret = ff_intel_h263_decode_picture_header(s);
  496.     } else if (CONFIG_FLV_DECODER && s->h263_flv) {
  497.         ret = ff_flv_decode_picture_header(s);
  498.     } else {
  499.         ret = ff_h263_decode_picture_header(s);
  500.     }
  501.  
  502.     if (ret < 0 || ret == FRAME_SKIPPED) {
  503.         if (   s->width  != avctx->coded_width
  504.             || s->height != avctx->coded_height) {
  505.                 av_log(s->avctx, AV_LOG_WARNING, "Reverting picture dimensions change due to header decoding failure\n");
  506.                 s->width = avctx->coded_width;
  507.                 s->height= avctx->coded_height;
  508.         }
  509.     }
  510.     if (ret == FRAME_SKIPPED)
  511.         return get_consumed_bytes(s, buf_size);
  512.  
  513.     /* skip if the header was thrashed */
  514.     if (ret < 0) {
  515.         av_log(s->avctx, AV_LOG_ERROR, "header damaged\n");
  516.         return ret;
  517.     }
  518.  
  519.     if (!s->context_initialized) {
  520.         avctx->pix_fmt = h263_get_format(avctx);
  521.         if ((ret = ff_mpv_common_init(s)) < 0)
  522.             return ret;
  523.     }
  524.  
  525.     if (!s->current_picture_ptr || s->current_picture_ptr->f->data[0]) {
  526.         int i = ff_find_unused_picture(s->avctx, s->picture, 0);
  527.         if (i < 0)
  528.             return i;
  529.         s->current_picture_ptr = &s->picture[i];
  530.     }
  531.  
  532.     avctx->has_b_frames = !s->low_delay;
  533.  
  534.     if (CONFIG_MPEG4_DECODER && avctx->codec_id == AV_CODEC_ID_MPEG4) {
  535.         if (ff_mpeg4_workaround_bugs(avctx) == 1)
  536.             goto retry;
  537.     }
  538.  
  539.     /* After H263 & mpeg4 header decode we have the height, width,
  540.      * and other parameters. So then we could init the picture.
  541.      * FIXME: By the way H263 decoder is evolving it should have
  542.      * an H263EncContext */
  543.     if (s->width  != avctx->coded_width  ||
  544.         s->height != avctx->coded_height ||
  545.         s->context_reinit) {
  546.         /* H.263 could change picture size any time */
  547.         s->context_reinit = 0;
  548.  
  549.         ret = ff_set_dimensions(avctx, s->width, s->height);
  550.         if (ret < 0)
  551.             return ret;
  552.  
  553.         ff_set_sar(avctx, avctx->sample_aspect_ratio);
  554.  
  555.         if ((ret = ff_mpv_common_frame_size_change(s)))
  556.             return ret;
  557.  
  558.         if (avctx->pix_fmt != h263_get_format(avctx)) {
  559.             av_log(avctx, AV_LOG_ERROR, "format change not supported\n");
  560.             avctx->pix_fmt = AV_PIX_FMT_NONE;
  561.             return AVERROR_UNKNOWN;
  562.         }
  563.     }
  564.  
  565.     if (s->codec_id == AV_CODEC_ID_H263  ||
  566.         s->codec_id == AV_CODEC_ID_H263P ||
  567.         s->codec_id == AV_CODEC_ID_H263I)
  568.         s->gob_index = H263_GOB_HEIGHT(s->height);
  569.  
  570.     // for skipping the frame
  571.     s->current_picture.f->pict_type = s->pict_type;
  572.     s->current_picture.f->key_frame = s->pict_type == AV_PICTURE_TYPE_I;
  573.  
  574.     /* skip B-frames if we don't have reference frames */
  575.     if (!s->last_picture_ptr &&
  576.         (s->pict_type == AV_PICTURE_TYPE_B || s->droppable))
  577.         return get_consumed_bytes(s, buf_size);
  578.     if ((avctx->skip_frame >= AVDISCARD_NONREF &&
  579.          s->pict_type == AV_PICTURE_TYPE_B)    ||
  580.         (avctx->skip_frame >= AVDISCARD_NONKEY &&
  581.          s->pict_type != AV_PICTURE_TYPE_I)    ||
  582.         avctx->skip_frame >= AVDISCARD_ALL)
  583.         return get_consumed_bytes(s, buf_size);
  584.  
  585.     if (s->next_p_frame_damaged) {
  586.         if (s->pict_type == AV_PICTURE_TYPE_B)
  587.             return get_consumed_bytes(s, buf_size);
  588.         else
  589.             s->next_p_frame_damaged = 0;
  590.     }
  591.  
  592.     if ((!s->no_rounding) || s->pict_type == AV_PICTURE_TYPE_B) {
  593.         s->me.qpel_put = s->qdsp.put_qpel_pixels_tab;
  594.         s->me.qpel_avg = s->qdsp.avg_qpel_pixels_tab;
  595.     } else {
  596.         s->me.qpel_put = s->qdsp.put_no_rnd_qpel_pixels_tab;
  597.         s->me.qpel_avg = s->qdsp.avg_qpel_pixels_tab;
  598.     }
  599.  
  600.     if ((ret = ff_mpv_frame_start(s, avctx)) < 0)
  601.         return ret;
  602.  
  603.     if (!s->divx_packed && !avctx->hwaccel)
  604.         ff_thread_finish_setup(avctx);
  605.  
  606. #if FF_API_CAP_VDPAU
  607.     if (CONFIG_MPEG4_VDPAU_DECODER && (s->avctx->codec->capabilities & AV_CODEC_CAP_HWACCEL_VDPAU)) {
  608.         ff_vdpau_mpeg4_decode_picture(avctx->priv_data, s->gb.buffer, s->gb.buffer_end - s->gb.buffer);
  609.         goto frame_end;
  610.     }
  611. #endif
  612.  
  613.     if (avctx->hwaccel) {
  614.         ret = avctx->hwaccel->start_frame(avctx, s->gb.buffer,
  615.                                           s->gb.buffer_end - s->gb.buffer);
  616.         if (ret < 0 )
  617.             return ret;
  618.     }
  619.  
  620.     ff_mpeg_er_frame_start(s);
  621.  
  622.     /* the second part of the wmv2 header contains the MB skip bits which
  623.      * are stored in current_picture->mb_type which is not available before
  624.      * ff_mpv_frame_start() */
  625.     if (CONFIG_WMV2_DECODER && s->msmpeg4_version == 5) {
  626.         ret = ff_wmv2_decode_secondary_picture_header(s);
  627.         if (ret < 0)
  628.             return ret;
  629.         if (ret == 1)
  630.             goto frame_end;
  631.     }
  632.  
  633.     /* decode each macroblock */
  634.     s->mb_x = 0;
  635.     s->mb_y = 0;
  636.  
  637.     slice_ret = decode_slice(s);
  638.     while (s->mb_y < s->mb_height) {
  639.         if (s->msmpeg4_version) {
  640.             if (s->slice_height == 0 || s->mb_x != 0 ||
  641.                 (s->mb_y % s->slice_height) != 0 || get_bits_left(&s->gb) < 0)
  642.                 break;
  643.         } else {
  644.             int prev_x = s->mb_x, prev_y = s->mb_y;
  645.             if (ff_h263_resync(s) < 0)
  646.                 break;
  647.             if (prev_y * s->mb_width + prev_x < s->mb_y * s->mb_width + s->mb_x)
  648.                 s->er.error_occurred = 1;
  649.         }
  650.  
  651.         if (s->msmpeg4_version < 4 && s->h263_pred)
  652.             ff_mpeg4_clean_buffers(s);
  653.  
  654.         if (decode_slice(s) < 0)
  655.             slice_ret = AVERROR_INVALIDDATA;
  656.     }
  657.  
  658.     if (s->msmpeg4_version && s->msmpeg4_version < 4 &&
  659.         s->pict_type == AV_PICTURE_TYPE_I)
  660.         if (!CONFIG_MSMPEG4_DECODER ||
  661.             ff_msmpeg4_decode_ext_header(s, buf_size) < 0)
  662.             s->er.error_status_table[s->mb_num - 1] = ER_MB_ERROR;
  663.  
  664.     av_assert1(s->bitstream_buffer_size == 0);
  665. frame_end:
  666.     ff_er_frame_end(&s->er);
  667.  
  668.     if (avctx->hwaccel) {
  669.         ret = avctx->hwaccel->end_frame(avctx);
  670.         if (ret < 0)
  671.             return ret;
  672.     }
  673.  
  674.     ff_mpv_frame_end(s);
  675.  
  676.     if (CONFIG_MPEG4_DECODER && avctx->codec_id == AV_CODEC_ID_MPEG4)
  677.         ff_mpeg4_frame_end(avctx, buf, buf_size);
  678.  
  679.     if (!s->divx_packed && avctx->hwaccel)
  680.         ff_thread_finish_setup(avctx);
  681.  
  682.     av_assert1(s->current_picture.f->pict_type == s->current_picture_ptr->f->pict_type);
  683.     av_assert1(s->current_picture.f->pict_type == s->pict_type);
  684.     if (s->pict_type == AV_PICTURE_TYPE_B || s->low_delay) {
  685.         if ((ret = av_frame_ref(pict, s->current_picture_ptr->f)) < 0)
  686.             return ret;
  687.         ff_print_debug_info(s, s->current_picture_ptr, pict);
  688.         ff_mpv_export_qp_table(s, pict, s->current_picture_ptr, FF_QSCALE_TYPE_MPEG1);
  689.     } else if (s->last_picture_ptr) {
  690.         if ((ret = av_frame_ref(pict, s->last_picture_ptr->f)) < 0)
  691.             return ret;
  692.         ff_print_debug_info(s, s->last_picture_ptr, pict);
  693.         ff_mpv_export_qp_table(s, pict, s->last_picture_ptr, FF_QSCALE_TYPE_MPEG1);
  694.     }
  695.  
  696.     if (s->last_picture_ptr || s->low_delay) {
  697.         if (   pict->format == AV_PIX_FMT_YUV420P
  698.             && (s->codec_tag == AV_RL32("GEOV") || s->codec_tag == AV_RL32("GEOX"))) {
  699.             int x, y, p;
  700.             av_frame_make_writable(pict);
  701.             for (p=0; p<3; p++) {
  702.                 int w = FF_CEIL_RSHIFT(pict-> width, !!p);
  703.                 int h = FF_CEIL_RSHIFT(pict->height, !!p);
  704.                 int linesize = pict->linesize[p];
  705.                 for (y=0; y<(h>>1); y++)
  706.                     for (x=0; x<w; x++)
  707.                         FFSWAP(int,
  708.                                pict->data[p][x + y*linesize],
  709.                                pict->data[p][x + (h-1-y)*linesize]);
  710.             }
  711.         }
  712.         *got_frame = 1;
  713.     }
  714.  
  715.     if (slice_ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE))
  716.         return ret;
  717.     else
  718.         return get_consumed_bytes(s, buf_size);
  719. }
  720.  
  721. const enum AVPixelFormat ff_h263_hwaccel_pixfmt_list_420[] = {
  722. #if CONFIG_H263_VAAPI_HWACCEL || CONFIG_MPEG4_VAAPI_HWACCEL
  723.     AV_PIX_FMT_VAAPI,
  724. #endif
  725. #if CONFIG_H263_VDPAU_HWACCEL || CONFIG_MPEG4_VDPAU_HWACCEL
  726.     AV_PIX_FMT_VDPAU,
  727. #endif
  728. #if CONFIG_H263_VIDEOTOOLBOX_HWACCEL || CONFIG_MPEG4_VIDEOTOOLBOX_HWACCEL
  729.     AV_PIX_FMT_VIDEOTOOLBOX,
  730. #endif
  731.     AV_PIX_FMT_YUV420P,
  732.     AV_PIX_FMT_NONE
  733. };
  734.  
  735. AVCodec ff_h263_decoder = {
  736.     .name           = "h263",
  737.     .long_name      = NULL_IF_CONFIG_SMALL("H.263 / H.263-1996, H.263+ / H.263-1998 / H.263 version 2"),
  738.     .type           = AVMEDIA_TYPE_VIDEO,
  739.     .id             = AV_CODEC_ID_H263,
  740.     .priv_data_size = sizeof(MpegEncContext),
  741.     .init           = ff_h263_decode_init,
  742.     .close          = ff_h263_decode_end,
  743.     .decode         = ff_h263_decode_frame,
  744.     .capabilities   = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 |
  745.                       AV_CODEC_CAP_TRUNCATED | AV_CODEC_CAP_DELAY,
  746.     .flush          = ff_mpeg_flush,
  747.     .max_lowres     = 3,
  748.     .pix_fmts       = ff_h263_hwaccel_pixfmt_list_420,
  749. };
  750.  
  751. AVCodec ff_h263p_decoder = {
  752.     .name           = "h263p",
  753.     .long_name      = NULL_IF_CONFIG_SMALL("H.263 / H.263-1996, H.263+ / H.263-1998 / H.263 version 2"),
  754.     .type           = AVMEDIA_TYPE_VIDEO,
  755.     .id             = AV_CODEC_ID_H263P,
  756.     .priv_data_size = sizeof(MpegEncContext),
  757.     .init           = ff_h263_decode_init,
  758.     .close          = ff_h263_decode_end,
  759.     .decode         = ff_h263_decode_frame,
  760.     .capabilities   = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 |
  761.                       AV_CODEC_CAP_TRUNCATED | AV_CODEC_CAP_DELAY,
  762.     .flush          = ff_mpeg_flush,
  763.     .max_lowres     = 3,
  764.     .pix_fmts       = ff_h263_hwaccel_pixfmt_list_420,
  765. };
  766.