text: /*
   * H.263 decoder
   * Copyright (c) 2001 Fabrice Bellard
   * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
   *
   * This file is part of FFmpeg.
   *
   * FFmpeg is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * FFmpeg is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with FFmpeg; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
   */
  
  /**
   * @file libavcodec/h263dec.c
   * H.263 decoder.
   */
  
  #include "internal.h"
  #include "avcodec.h"
  #include "dsputil.h"
  #include "mpegvideo.h"
  #include "h263_parser.h"
  #include "mpeg4video_parser.h"
  #include "msmpeg4.h"
  
  //#define DEBUG
  //#define PRINT_FRAME_TIME
  
  av_cold int ff_h263_decode_init(AVCodecContext *avctx)
  {
      MpegEncContext *s = avctx->priv_data;
  
      s->avctx = avctx;
      s->out_format = FMT_H263;
  
      s->width  = avctx->coded_width;
      s->height = avctx->coded_height;
      s->workaround_bugs= avctx->workaround_bugs;
  
      // set defaults
      MPV_decode_defaults(s);
      s->quant_precision=5;
      s->decode_mb= ff_h263_decode_mb;
      s->low_delay= 1;
      avctx->pix_fmt= avctx->get_format(avctx, avctx->codec->pix_fmts);
      s->unrestricted_mv= 1;
  
      /* select sub codec */
      switch(avctx->codec->id) {
      case CODEC_ID_H263:
          s->unrestricted_mv= 0;
          break;
      case CODEC_ID_MPEG4:
          s->decode_mb= ff_mpeg4_decode_mb;
          s->time_increment_bits = 4; /* default value for broken headers */
          s->h263_pred = 1;
          s->low_delay = 0; //default, might be overriden in the vol header during header parsing
          break;
      case CODEC_ID_MSMPEG4V1:
          s->h263_msmpeg4 = 1;
          s->h263_pred = 1;
          s->msmpeg4_version=1;
          break;
      case CODEC_ID_MSMPEG4V2:
          s->h263_msmpeg4 = 1;
          s->h263_pred = 1;
          s->msmpeg4_version=2;
          break;
      case CODEC_ID_MSMPEG4V3:
          s->h263_msmpeg4 = 1;
          s->h263_pred = 1;
          s->msmpeg4_version=3;
          break;
      case CODEC_ID_WMV1:
          s->h263_msmpeg4 = 1;
          s->h263_pred = 1;
          s->msmpeg4_version=4;
          break;
      case CODEC_ID_WMV2:
          s->h263_msmpeg4 = 1;
          s->h263_pred = 1;
          s->msmpeg4_version=5;
          break;
      case CODEC_ID_VC1:
      case CODEC_ID_WMV3:
          s->h263_msmpeg4 = 1;
          s->h263_pred = 1;
          s->msmpeg4_version=6;
          break;
      case CODEC_ID_H263I:
          break;
      case CODEC_ID_FLV1:
          s->h263_flv = 1;
          break;
      default:
          return -1;
      }
      s->codec_id= avctx->codec->id;
      avctx->hwaccel= ff_find_hwaccel(avctx->codec->id, avctx->pix_fmt);
  
      /* for h263, we allocate the images after having read the header */
      if (avctx->codec->id != CODEC_ID_H263 && avctx->codec->id != CODEC_ID_MPEG4)
          if (MPV_common_init(s) < 0)
              return -1;
  
      if (CONFIG_MSMPEG4_DECODER && s->h263_msmpeg4)
          ff_msmpeg4_decode_init(s);
      else
          h263_decode_init_vlc(s);
  
      return 0;
  }
  
  av_cold int ff_h263_decode_end(AVCodecContext *avctx)
  {
      MpegEncContext *s = avctx->priv_data;
  
      MPV_common_end(s);
      return 0;
  }
  
  /**
   * returns the number of bytes consumed for building the current frame
   */
  static int get_consumed_bytes(MpegEncContext *s, int buf_size){
      int pos= (get_bits_count(&s->gb)+7)>>3;
  
      if(s->divx_packed || s->avctx->hwaccel){
          //we would have to scan through the whole buf to handle the weird reordering ...
          return buf_size;
      }else if(s->flags&CODEC_FLAG_TRUNCATED){
          pos -= s->parse_context.last_index;
          if(pos<0) pos=0; // padding is not really read so this might be -1
          return pos;
      }else{
          if(pos==0) pos=1; //avoid infinite loops (i doubt that is needed but ...)
          if(pos+10>buf_size) pos=buf_size; // oops ;)
  
          return pos;
      }
  }
  
  static int decode_slice(MpegEncContext *s){
      const int part_mask= s->partitioned_frame ? (AC_END|AC_ERROR) : 0x7F;
      const int mb_size= 16>>s->avctx->lowres;
      s->last_resync_gb= s->gb;
      s->first_slice_line= 1;
  
      s->resync_mb_x= s->mb_x;
      s->resync_mb_y= s->mb_y;
  
      ff_set_qscale(s, s->qscale);
  
      if (s->avctx->hwaccel) {
          const uint8_t *start= s->gb.buffer + get_bits_count(&s->gb)/8;
          const uint8_t *end  = ff_h263_find_resync_marker(start + 1, s->gb.buffer_end);
          skip_bits_long(&s->gb, 8*(end - start));
          return s->avctx->hwaccel->decode_slice(s->avctx, start, end - start);
      }
  
      if(s->partitioned_frame){
          const int qscale= s->qscale;
  
          if(s->codec_id==CODEC_ID_MPEG4){
              if(ff_mpeg4_decode_partitions(s) < 0)
                  return -1;
          }
  
          /* restore variables which were modified */
          s->first_slice_line=1;
          s->mb_x= s->resync_mb_x;
          s->mb_y= s->resync_mb_y;
          ff_set_qscale(s, qscale);
      }
  
      for(; s->mb_y < s->mb_height; s->mb_y++) {
          /* per-row end of slice checks */
          if(s->msmpeg4_version){
              if(s->resync_mb_y + s->slice_height == s->mb_y){
                  ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, AC_END|DC_END|MV_END);
  
                  return 0;
              }
          }
  
          if(s->msmpeg4_version==1){
              s->last_dc[0]=
              s->last_dc[1]=
              s->last_dc[2]= 128;
          }
  
          ff_init_block_index(s);
          for(; s->mb_x < s->mb_width; s->mb_x++) {
              int ret;
  
              ff_update_block_index(s);
  
              if(s->resync_mb_x == s->mb_x && s->resync_mb_y+1 == s->mb_y){
                  s->first_slice_line=0;
              }
  
              /* DCT & quantize */
  
              s->mv_dir = MV_DIR_FORWARD;
              s->mv_type = MV_TYPE_16X16;
  //            s->mb_skipped = 0;
  //printf("%d %d %06X\n", ret, get_bits_count(&s->gb), show_bits(&s->gb, 24));
              ret= s->decode_mb(s, s->block);
  
              if (s->pict_type!=FF_B_TYPE)
                  ff_h263_update_motion_val(s);
  
              if(ret<0){
                  const int xy= s->mb_x + s->mb_y*s->mb_stride;
                  if(ret==SLICE_END){
                      MPV_decode_mb(s, s->block);
                      if(s->loop_filter)
                          ff_h263_loop_filter(s);
  
  //printf("%d %d %d %06X\n", s->mb_x, s->mb_y, s->gb.size*8 - get_bits_count(&s->gb), show_bits(&s->gb, 24));
                      ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, (AC_END|DC_END|MV_END)&part_mask);
  
                      s->padding_bug_score--;
  
                      if(++s->mb_x >= s->mb_width){
                          s->mb_x=0;
                          ff_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
                          s->mb_y++;
                      }
                      return 0;
                  }else if(ret==SLICE_NOEND){
                      av_log(s->avctx, AV_LOG_ERROR, "Slice mismatch at MB: %d\n", xy);
                      ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x+1, s->mb_y, (AC_END|DC_END|MV_END)&part_mask);
                      return -1;
                  }
                  av_log(s->avctx, AV_LOG_ERROR, "Error at MB: %d\n", xy);
                  ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, (AC_ERROR|DC_ERROR|MV_ERROR)&part_mask);
  
                  return -1;
              }
  
              MPV_decode_mb(s, s->block);
              if(s->loop_filter)
                  ff_h263_loop_filter(s);
          }
  
          ff_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
  
          s->mb_x= 0;
      }
  
      assert(s->mb_x==0 && s->mb_y==s->mb_height);
  
      /* try to detect the padding bug */
      if(      s->codec_id==CODEC_ID_MPEG4
         &&   (s->workaround_bugs&FF_BUG_AUTODETECT)
         &&    s->gb.size_in_bits - get_bits_count(&s->gb) >=0
         &&    s->gb.size_in_bits - get_bits_count(&s->gb) < 48
  //       &&   !s->resync_marker
         &&   !s->data_partitioning){
  
          const int bits_count= get_bits_count(&s->gb);
          const int bits_left = s->gb.size_in_bits - bits_count;
  
          if(bits_left==0){
              s->padding_bug_score+=16;
          } else if(bits_left != 1){
              int v= show_bits(&s->gb, 8);
              v|= 0x7F >> (7-(bits_count&7));
  
              if(v==0x7F && bits_left<=8)
                  s->padding_bug_score--;
              else if(v==0x7F && ((get_bits_count(&s->gb)+8)&8) && bits_left<=16)
                  s->padding_bug_score+= 4;
              else
                  s->padding_bug_score++;
          }
      }
  
      if(s->workaround_bugs&FF_BUG_AUTODETECT){
          if(s->padding_bug_score > -2 && !s->data_partitioning /*&& (s->divx_version || !s->resync_marker)*/)
              s->workaround_bugs |=  FF_BUG_NO_PADDING;
          else
              s->workaround_bugs &= ~FF_BUG_NO_PADDING;
      }
  
      // handle formats which don't have unique end markers
      if(s->msmpeg4_version || (s->workaround_bugs&FF_BUG_NO_PADDING)){ //FIXME perhaps solve this more cleanly
          int left= s->gb.size_in_bits - get_bits_count(&s->gb);
          int max_extra=7;
  
          /* no markers in M$ crap */
          if(s->msmpeg4_version && s->pict_type==FF_I_TYPE)
              max_extra+= 17;
  
          /* buggy padding but the frame should still end approximately at the bitstream end */
          if((s->workaround_bugs&FF_BUG_NO_PADDING) && s->error_recognition>=3)
              max_extra+= 48;
          else if((s->workaround_bugs&FF_BUG_NO_PADDING))
              max_extra+= 256*256*256*64;
  
          if(left>max_extra){
              av_log(s->avctx, AV_LOG_ERROR, "discarding %d junk bits at end, next would be %X\n", left, show_bits(&s->gb, 24));
          }
          else if(left<0){
              av_log(s->avctx, AV_LOG_ERROR, "overreading %d bits\n", -left);
          }else
              ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, AC_END|DC_END|MV_END);
  
          return 0;
      }
  
      av_log(s->avctx, AV_LOG_ERROR, "slice end not reached but screenspace end (%d left %06X, score= %d)\n",
              s->gb.size_in_bits - get_bits_count(&s->gb),
              show_bits(&s->gb, 24), s->padding_bug_score);
  
      ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, (AC_END|DC_END|MV_END)&part_mask);
  
      return -1;
  }
  
  int ff_h263_decode_frame(AVCodecContext *avctx,
                               void *data, int *data_size,
                               const uint8_t *buf, int buf_size)
  {
      MpegEncContext *s = avctx->priv_data;
      int ret;
      AVFrame *pict = data;
  
  #ifdef PRINT_FRAME_TIME
  uint64_t time= rdtsc();
  #endif
  #ifdef DEBUG
      av_log(avctx, AV_LOG_DEBUG, "*****frame %d size=%d\n", avctx->frame_number, buf_size);
      if(buf_size>0)
          av_log(avctx, AV_LOG_DEBUG, "bytes=%x %x %x %x\n", buf[0], buf[1], buf[2], buf[3]);
  #endif
      s->flags= avctx->flags;
      s->flags2= avctx->flags2;
  
      /* no supplementary picture */
      if (buf_size == 0) {
          /* special case for last picture */
          if (s->low_delay==0 && s->next_picture_ptr) {
              *pict= *(AVFrame*)s->next_picture_ptr;
              s->next_picture_ptr= NULL;
  
              *data_size = sizeof(AVFrame);
          }
  
          return 0;
      }
  
      if(s->flags&CODEC_FLAG_TRUNCATED){
          int next;
  
          if(CONFIG_MPEG4_DECODER && s->codec_id==CODEC_ID_MPEG4){
              next= ff_mpeg4_find_frame_end(&s->parse_context, buf, buf_size);
          }else if(CONFIG_H263_DECODER && s->codec_id==CODEC_ID_H263){
              next= ff_h263_find_frame_end(&s->parse_context, buf, buf_size);
          }else{
              av_log(s->avctx, AV_LOG_ERROR, "this codec does not support truncated bitstreams\n");
              return -1;
          }
  
          if( ff_combine_frame(&s->parse_context, next, (const uint8_t **)&buf, &buf_size) < 0 )
              return buf_size;
      }
  
  
  retry:
  
      if(s->bitstream_buffer_size && (s->divx_packed || buf_size<20)){ //divx 5.01+/xvid frame reorder
          init_get_bits(&s->gb, s->bitstream_buffer, s->bitstream_buffer_size*8);
      }else
          init_get_bits(&s->gb, buf, buf_size*8);
      s->bitstream_buffer_size=0;
  
      if (!s->context_initialized) {
          if (MPV_common_init(s) < 0) //we need the idct permutaton for reading a custom matrix
              return -1;
      }
  
      /* We need to set current_picture_ptr before reading the header,
       * otherwise we cannot store anyting in there */
      if(s->current_picture_ptr==NULL || s->current_picture_ptr->data[0]){
          int i= ff_find_unused_picture(s, 0);
          s->current_picture_ptr= &s->picture[i];
      }
  
      /* let's go :-) */
      if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5) {
          ret= ff_wmv2_decode_picture_header(s);
      } else if (CONFIG_MSMPEG4_DECODER && s->msmpeg4_version) {
          ret = msmpeg4_decode_picture_header(s);
      } else if (s->h263_pred) {
          if(s->avctx->extradata_size && s->picture_number==0){
              GetBitContext gb;
  
              init_get_bits(&gb, s->avctx->extradata, s->avctx->extradata_size*8);
              ret = ff_mpeg4_decode_picture_header(s, &gb);
          }
          ret = ff_mpeg4_decode_picture_header(s, &s->gb);
      } else if (s->codec_id == CODEC_ID_H263I) {
          ret = intel_h263_decode_picture_header(s);
      } else if (s->h263_flv) {
          ret = flv_h263_decode_picture_header(s);
      } else {
          ret = h263_decode_picture_header(s);
      }
  
      if(ret==FRAME_SKIPPED) return get_consumed_bytes(s, buf_size);
  
      /* skip if the header was thrashed */
      if (ret < 0){
          av_log(s->avctx, AV_LOG_ERROR, "header damaged\n");
          return -1;
      }
  
      avctx->has_b_frames= !s->low_delay;
  
      if(s->xvid_build==0 && s->divx_version==0 && s->lavc_build==0){
          if(s->stream_codec_tag == AV_RL32("XVID") ||
             s->codec_tag == AV_RL32("XVID") || s->codec_tag == AV_RL32("XVIX") ||
             s->codec_tag == AV_RL32("RMP4"))
              s->xvid_build= -1;
  #if 0
          if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==1
             && s->padding_bug_score > 0 && s->low_delay) // XVID with modified fourcc
              s->xvid_build= -1;
  #endif
      }
  
      if(s->xvid_build==0 && s->divx_version==0 && s->lavc_build==0){
          if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==0)
              s->divx_version= 400; //divx 4
      }
  
      if(s->xvid_build && s->divx_version){
          s->divx_version=
          s->divx_build= 0;
      }
  
      if(s->workaround_bugs&FF_BUG_AUTODETECT){
          if(s->codec_tag == AV_RL32("XVIX"))
              s->workaround_bugs|= FF_BUG_XVID_ILACE;
  
          if(s->codec_tag == AV_RL32("UMP4")){
              s->workaround_bugs|= FF_BUG_UMP4;
          }
  
          if(s->divx_version>=500 && s->divx_build<1814){
              s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
          }
  
          if(s->divx_version>502 && s->divx_build<1814){
              s->workaround_bugs|= FF_BUG_QPEL_CHROMA2;
          }
  
          if(s->xvid_build && s->xvid_build<=3)
              s->padding_bug_score= 256*256*256*64;
  
          if(s->xvid_build && s->xvid_build<=1)
              s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
  
          if(s->xvid_build && s->xvid_build<=12)
              s->workaround_bugs|= FF_BUG_EDGE;
  
          if(s->xvid_build && s->xvid_build<=32)
              s->workaround_bugs|= FF_BUG_DC_CLIP;
  
  #define SET_QPEL_FUNC(postfix1, postfix2) \
      s->dsp.put_ ## postfix1 = ff_put_ ## postfix2;\
      s->dsp.put_no_rnd_ ## postfix1 = ff_put_no_rnd_ ## postfix2;\
      s->dsp.avg_ ## postfix1 = ff_avg_ ## postfix2;
  
          if(s->lavc_build && s->lavc_build<4653)
              s->workaround_bugs|= FF_BUG_STD_QPEL;
  
          if(s->lavc_build && s->lavc_build<4655)
              s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
  
          if(s->lavc_build && s->lavc_build<4670){
              s->workaround_bugs|= FF_BUG_EDGE;
          }
  
          if(s->lavc_build && s->lavc_build<=4712)
              s->workaround_bugs|= FF_BUG_DC_CLIP;
  
          if(s->divx_version)
              s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
  //printf("padding_bug_score: %d\n", s->padding_bug_score);
          if(s->divx_version==501 && s->divx_build==20020416)
              s->padding_bug_score= 256*256*256*64;
  
          if(s->divx_version && s->divx_version<500){
              s->workaround_bugs|= FF_BUG_EDGE;
          }
  
          if(s->divx_version)
              s->workaround_bugs|= FF_BUG_HPEL_CHROMA;
  #if 0
          if(s->divx_version==500)
              s->padding_bug_score= 256*256*256*64;
  
          /* very ugly XVID padding bug detection FIXME/XXX solve this differently
           * Let us hope this at least works.
           */
          if(   s->resync_marker==0 && s->data_partitioning==0 && s->divx_version==0
             && s->codec_id==CODEC_ID_MPEG4 && s->vo_type==0)
              s->workaround_bugs|= FF_BUG_NO_PADDING;
  
          if(s->lavc_build && s->lavc_build<4609) //FIXME not sure about the version num but a 4609 file seems ok
              s->workaround_bugs|= FF_BUG_NO_PADDING;
  #endif
      }
  
      if(s->workaround_bugs& FF_BUG_STD_QPEL){
          SET_QPEL_FUNC(qpel_pixels_tab[0][ 5], qpel16_mc11_old_c)
          SET_QPEL_FUNC(qpel_pixels_tab[0][ 7], qpel16_mc31_old_c)
          SET_QPEL_FUNC(qpel_pixels_tab[0][ 9], qpel16_mc12_old_c)
          SET_QPEL_FUNC(qpel_pixels_tab[0][11], qpel16_mc32_old_c)
          SET_QPEL_FUNC(qpel_pixels_tab[0][13], qpel16_mc13_old_c)
          SET_QPEL_FUNC(qpel_pixels_tab[0][15], qpel16_mc33_old_c)
  
          SET_QPEL_FUNC(qpel_pixels_tab[1][ 5], qpel8_mc11_old_c)
          SET_QPEL_FUNC(qpel_pixels_tab[1][ 7], qpel8_mc31_old_c)
          SET_QPEL_FUNC(qpel_pixels_tab[1][ 9], qpel8_mc12_old_c)
          SET_QPEL_FUNC(qpel_pixels_tab[1][11], qpel8_mc32_old_c)
          SET_QPEL_FUNC(qpel_pixels_tab[1][13], qpel8_mc13_old_c)
          SET_QPEL_FUNC(qpel_pixels_tab[1][15], qpel8_mc33_old_c)
      }
  
      if(avctx->debug & FF_DEBUG_BUGS)
          av_log(s->avctx, AV_LOG_DEBUG, "bugs: %X lavc_build:%d xvid_build:%d divx_version:%d divx_build:%d %s\n",
                 s->workaround_bugs, s->lavc_build, s->xvid_build, s->divx_version, s->divx_build,
                 s->divx_packed ? "p" : "");
  
  #if 0 // dump bits per frame / qp / complexity
  {
      static FILE *f=NULL;
      if(!f) f=fopen("rate_qp_cplx.txt", "w");
      fprintf(f, "%d %d %f\n", buf_size, s->qscale, buf_size*(double)s->qscale);
  }
  #endif
  
  #if HAVE_MMX
      if(s->codec_id == CODEC_ID_MPEG4 && s->xvid_build && avctx->idct_algo == FF_IDCT_AUTO && (mm_flags & FF_MM_MMX)){
          avctx->idct_algo= FF_IDCT_XVIDMMX;
          avctx->coded_width= 0; // force reinit
  //        dsputil_init(&s->dsp, avctx);
          s->picture_number=0;
      }
  #endif
  
          /* After H263 & mpeg4 header decode we have the height, width,*/
          /* and other parameters. So then we could init the picture   */
          /* FIXME: By the way H263 decoder is evolving it should have */
          /* an H263EncContext                                         */
  
      if (   s->width  != avctx->coded_width
          || s->height != avctx->coded_height) {
          /* H.263 could change picture size any time */
          ParseContext pc= s->parse_context; //FIXME move these demuxng hack to avformat
          s->parse_context.buffer=0;
          MPV_common_end(s);
          s->parse_context= pc;
      }
      if (!s->context_initialized) {
          avcodec_set_dimensions(avctx, s->width, s->height);
  
          goto retry;
      }
  
      if((s->codec_id==CODEC_ID_H263 || s->codec_id==CODEC_ID_H263P || s->codec_id == CODEC_ID_H263I))
          s->gob_index = ff_h263_get_gob_height(s);
  
      // for hurry_up==5
      s->current_picture.pict_type= s->pict_type;
      s->current_picture.key_frame= s->pict_type == FF_I_TYPE;
  
      /* skip B-frames if we don't have reference frames */
      if(s->last_picture_ptr==NULL && (s->pict_type==FF_B_TYPE || s->dropable)) return get_consumed_bytes(s, buf_size);
      /* skip b frames if we are in a hurry */
      if(avctx->hurry_up && s->pict_type==FF_B_TYPE) return get_consumed_bytes(s, buf_size);
      if(   (avctx->skip_frame >= AVDISCARD_NONREF && s->pict_type==FF_B_TYPE)
         || (avctx->skip_frame >= AVDISCARD_NONKEY && s->pict_type!=FF_I_TYPE)
         ||  avctx->skip_frame >= AVDISCARD_ALL)
          return get_consumed_bytes(s, buf_size);
      /* skip everything if we are in a hurry>=5 */
      if(avctx->hurry_up>=5) return get_consumed_bytes(s, buf_size);
  
      if(s->next_p_frame_damaged){
          if(s->pict_type==FF_B_TYPE)
              return get_consumed_bytes(s, buf_size);
          else
              s->next_p_frame_damaged=0;
      }
  
      if((s->avctx->flags2 & CODEC_FLAG2_FAST) && s->pict_type==FF_B_TYPE){
          s->me.qpel_put= s->dsp.put_2tap_qpel_pixels_tab;
          s->me.qpel_avg= s->dsp.avg_2tap_qpel_pixels_tab;
      }else if((!s->no_rounding) || s->pict_type==FF_B_TYPE){
          s->me.qpel_put= s->dsp.put_qpel_pixels_tab;
          s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
      }else{
          s->me.qpel_put= s->dsp.put_no_rnd_qpel_pixels_tab;
          s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
      }
  
      if(MPV_frame_start(s, avctx) < 0)
          return -1;
  
      if (avctx->hwaccel) {
          if (avctx->hwaccel->start_frame(avctx, buf, buf_size) < 0)
              return -1;
      }
  
  #ifdef DEBUG
      av_log(avctx, AV_LOG_DEBUG, "qscale=%d\n", s->qscale);
  #endif
  
      ff_er_frame_start(s);
  
      //the second part of the wmv2 header contains the MB skip bits which are stored in current_picture->mb_type
      //which is not available before MPV_frame_start()
      if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5){
          ret = ff_wmv2_decode_secondary_picture_header(s);
          if(ret<0) return ret;
          if(ret==1) goto intrax8_decoded;
      }
  
      /* decode each macroblock */
      s->mb_x=0;
      s->mb_y=0;
  
      decode_slice(s);
      while(s->mb_y<s->mb_height){
          if(s->msmpeg4_version){
              if(s->slice_height==0 || s->mb_x!=0 || (s->mb_y%s->slice_height)!=0 || get_bits_count(&s->gb) > s->gb.size_in_bits)
                  break;
          }else{
              if(ff_h263_resync(s)<0)
                  break;
          }
  
          if(s->msmpeg4_version<4 && s->h263_pred)
              ff_mpeg4_clean_buffers(s);
  
          decode_slice(s);
      }
  
      if (s->h263_msmpeg4 && s->msmpeg4_version<4 && s->pict_type==FF_I_TYPE)
          if(!CONFIG_MSMPEG4_DECODER || msmpeg4_decode_ext_header(s, buf_size) < 0){
              s->error_status_table[s->mb_num-1]= AC_ERROR|DC_ERROR|MV_ERROR;
          }
  
      /* divx 5.01+ bistream reorder stuff */
      if(s->codec_id==CODEC_ID_MPEG4 && s->bitstream_buffer_size==0 && s->divx_packed){
          int current_pos= get_bits_count(&s->gb)>>3;
          int startcode_found=0;
  
          if(buf_size - current_pos > 5){
              int i;
              for(i=current_pos; i<buf_size-3; i++){
                  if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1 && buf[i+3]==0xB6){
                      startcode_found=1;
                      break;
                  }
              }
          }
          if(s->gb.buffer == s->bitstream_buffer && buf_size>20){ //xvid style
              startcode_found=1;
              current_pos=0;
          }
  
          if(startcode_found){
              s->bitstream_buffer= av_fast_realloc(
                  s->bitstream_buffer,
                  &s->allocated_bitstream_buffer_size,
                  buf_size - current_pos + FF_INPUT_BUFFER_PADDING_SIZE);
              memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);
              s->bitstream_buffer_size= buf_size - current_pos;
          }
      }
  
  intrax8_decoded:
      ff_er_frame_end(s);
  
      if (avctx->hwaccel) {
          if (avctx->hwaccel->end_frame(avctx) < 0)
              return -1;
      }
  
      MPV_frame_end(s);
  
  assert(s->current_picture.pict_type == s->current_picture_ptr->pict_type);
  assert(s->current_picture.pict_type == s->pict_type);
      if (s->pict_type == FF_B_TYPE || s->low_delay) {
          *pict= *(AVFrame*)s->current_picture_ptr;
      } else if (s->last_picture_ptr != NULL) {
          *pict= *(AVFrame*)s->last_picture_ptr;
      }
  
      if(s->last_picture_ptr || s->low_delay){
          *data_size = sizeof(AVFrame);
          ff_print_debug_info(s, pict);
      }
  
      /* Return the Picture timestamp as the frame number */
      /* we subtract 1 because it is added on utils.c     */
      avctx->frame_number = s->picture_number - 1;
  
  #ifdef PRINT_FRAME_TIME
  av_log(avctx, AV_LOG_DEBUG, "%"PRId64"\n", rdtsc()-time);
  #endif
  
      return get_consumed_bytes(s, buf_size);
  }
  
  AVCodec mpeg4_decoder = {
      "mpeg4",
      CODEC_TYPE_VIDEO,
      CODEC_ID_MPEG4,
      sizeof(MpegEncContext),
      ff_h263_decode_init,
      NULL,
      ff_h263_decode_end,
      ff_h263_decode_frame,
      CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
      .flush= ff_mpeg_flush,
      .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2"),
      .pix_fmts= ff_hwaccel_pixfmt_list_420,
  };
  
  AVCodec h263_decoder = {
      "h263",
      CODEC_TYPE_VIDEO,
      CODEC_ID_H263,
      sizeof(MpegEncContext),
      ff_h263_decode_init,
      NULL,
      ff_h263_decode_end,
      ff_h263_decode_frame,
      CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
      .flush= ff_mpeg_flush,
      .long_name= NULL_IF_CONFIG_SMALL("H.263 / H.263-1996, H.263+ / H.263-1998 / H.263 version 2"),
      .pix_fmts= ff_hwaccel_pixfmt_list_420,
  };
  
  AVCodec msmpeg4v1_decoder = {
      "msmpeg4v1",
      CODEC_TYPE_VIDEO,
      CODEC_ID_MSMPEG4V1,
      sizeof(MpegEncContext),
      ff_h263_decode_init,
      NULL,
      ff_h263_decode_end,
      ff_h263_decode_frame,
      CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
      .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2 Microsoft variant version 1"),
      .pix_fmts= ff_pixfmt_list_420,
  };
  
  AVCodec msmpeg4v2_decoder = {
      "msmpeg4v2",
      CODEC_TYPE_VIDEO,
      CODEC_ID_MSMPEG4V2,
      sizeof(MpegEncContext),
      ff_h263_decode_init,
      NULL,
      ff_h263_decode_end,
      ff_h263_decode_frame,
      CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
      .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2 Microsoft variant version 2"),
      .pix_fmts= ff_pixfmt_list_420,
  };
  
  AVCodec msmpeg4v3_decoder = {
      "msmpeg4",
      CODEC_TYPE_VIDEO,
      CODEC_ID_MSMPEG4V3,
      sizeof(MpegEncContext),
      ff_h263_decode_init,
      NULL,
      ff_h263_decode_end,
      ff_h263_decode_frame,
      CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
      .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2 Microsoft variant version 3"),
      .pix_fmts= ff_pixfmt_list_420,
  };
  
  AVCodec wmv1_decoder = {
      "wmv1",
      CODEC_TYPE_VIDEO,
      CODEC_ID_WMV1,
      sizeof(MpegEncContext),
      ff_h263_decode_init,
      NULL,
      ff_h263_decode_end,
      ff_h263_decode_frame,
      CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
      .long_name= NULL_IF_CONFIG_SMALL("Windows Media Video 7"),
      .pix_fmts= ff_pixfmt_list_420,
  };
  
  AVCodec h263i_decoder = {
      "h263i",
      CODEC_TYPE_VIDEO,
      CODEC_ID_H263I,
      sizeof(MpegEncContext),
      ff_h263_decode_init,
      NULL,
      ff_h263_decode_end,
      ff_h263_decode_frame,
      CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
      .long_name = NULL_IF_CONFIG_SMALL("Intel H.263"),
      .pix_fmts= ff_pixfmt_list_420,
  };
  
  AVCodec flv_decoder = {
      "flv",
      CODEC_TYPE_VIDEO,
      CODEC_ID_FLV1,
      sizeof(MpegEncContext),
      ff_h263_decode_init,
      NULL,
      ff_h263_decode_end,
      ff_h263_decode_frame,
      CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
      .long_name= NULL_IF_CONFIG_SMALL("Flash Video (FLV)"),
      .pix_fmts= ff_pixfmt_list_420,
  };
  