h263dec.c

Trolltech公司发布的图形界面操作系统。可在qt-embedded-2.3.7平台上编译为嵌入式图形界面操作系统。

            memcpy(&pc->buffer[pc->index], buf, next + FF_INPUT_BUFFER_PADDING_SIZE );
            pc->index = 0;
            buf= pc->buffer;
            buf_size= pc->last_index + next;
        }
    }

retry:
    
    if(s->bitstream_buffer_size && buf_size<20){ //divx 5.01+ frame reorder
        init_get_bits(&s->gb, s->bitstream_buffer, s->bitstream_buffer_size);
    }else
        init_get_bits(&s->gb, buf, buf_size);
    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;
    }
        
    /* let's go :-) */
    if (s->h263_msmpeg4) {
        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);
            ret = ff_mpeg4_decode_picture_header(s, &gb);
        }
        ret = ff_mpeg4_decode_picture_header(s, &s->gb);

        if(s->flags& CODEC_FLAG_LOW_DELAY)
            s->low_delay=1;

        s->has_b_frames= !s->low_delay;
    } else if (s->h263_intel) {
        ret = intel_h263_decode_picture_header(s);
    } else {
        ret = h263_decode_picture_header(s);
    }
    avctx->has_b_frames= s->has_b_frames;

    if(s->workaround_bugs&FF_BUG_AUTODETECT){
        if(s->avctx->fourcc == ff_get_fourcc("XVIX")) 
            s->workaround_bugs|= FF_BUG_XVID_ILACE;

        if(s->avctx->fourcc == ff_get_fourcc("MP4S")) 
            s->workaround_bugs|= FF_BUG_AC_VLC;
        
        if(s->avctx->fourcc == ff_get_fourcc("M4S2")) 
            s->workaround_bugs|= FF_BUG_AC_VLC;
                
        if(s->avctx->fourcc == ff_get_fourcc("UMP4")){
            s->workaround_bugs|= FF_BUG_UMP4;
            s->workaround_bugs|= FF_BUG_AC_VLC;
        }

        if(s->divx_version){
            s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
        }

        if(s->avctx->fourcc == ff_get_fourcc("XVID") && s->xvid_build==0)
            s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
        
        if(s->xvid_build && s->xvid_build<=1)
            s->workaround_bugs|= FF_BUG_QPEL_CHROMA;

//printf("padding_bug_score: %d\n", s->padding_bug_score);
#if 0
        if(s->divx_version==500)
            s->workaround_bugs|= FF_BUG_NO_PADDING;

        /* very ugly XVID padding bug detection FIXME/XXX solve this differently
         * lets 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 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
       
        /* 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->aspected_height)
        new_aspect= (float)s->aspected_width / (float)s->aspected_height;
    else
        new_aspect=0;

    if (   s->width != avctx->width || s->height != avctx->height 
        || ABS(new_aspect - avctx->aspect_ratio) > 0.001) {
        /* H.263 could change picture size any time */
        MPV_common_end(s);
        s->context_initialized=0;
    }
    if (!s->context_initialized) {
        avctx->aspect_ratio= new_aspect;

        goto retry;
    }

    if((s->codec_id==CODEC_ID_H263 || s->codec_id==CODEC_ID_H263P))
        s->gob_index = ff_h263_get_gob_height(s);

    if(ret==FRAME_SKIPED) return get_consumed_bytes(s, buf_size);
    /* skip if the header was thrashed */
    if (ret < 0){
        fprintf(stderr, "header damaged\n");
        return -1;
    }
    
    s->avctx->key_frame   = (s->pict_type == I_TYPE);
    s->avctx->pict_type   = s->pict_type;

    /* skip b frames if we dont have reference frames */
    if(s->num_available_buffers<2 && s->pict_type==B_TYPE) return get_consumed_bytes(s, buf_size);
    /* skip b frames if we are in a hurry */
    if(s->hurry_up && s->pict_type==B_TYPE) return get_consumed_bytes(s, buf_size);
    /* skip everything if we are in a hurry>=5 */
    if(s->hurry_up>=5) return get_consumed_bytes(s, buf_size);
    
    if(s->next_p_frame_damaged){
        if(s->pict_type==B_TYPE)
            return get_consumed_bytes(s, buf_size);
        else
            s->next_p_frame_damaged=0;
    }

    if(MPV_frame_start(s, avctx) < 0)
        return -1;

#ifdef DEBUG
    printf("qscale=%d\n", s->qscale);
#endif

    if(s->error_resilience)
        memset(s->error_status_table, MV_ERROR|AC_ERROR|DC_ERROR|VP_START|AC_END|DC_END|MV_END, s->mb_num*sizeof(UINT8));
    
    /* decode each macroblock */
    s->block_wrap[0]=
    s->block_wrap[1]=
    s->block_wrap[2]=
    s->block_wrap[3]= s->mb_width*2 + 2;
    s->block_wrap[4]=
    s->block_wrap[5]= s->mb_width + 2;
    s->mb_x=0; 
    s->mb_y=0;
    
    decode_slice(s);
    s->error_status_table[0]|= VP_START;
    while(s->mb_y<s->mb_height && s->gb.size*8 - get_bits_count(&s->gb)>16){
        if(s->msmpeg4_version){
            if(s->mb_x!=0 || (s->mb_y%s->slice_height)!=0)
                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);

        s->error_status_table[s->resync_mb_x + s->resync_mb_y*s->mb_width]|= VP_START;
    }

    if (s->h263_msmpeg4 && s->msmpeg4_version<4 && s->pict_type==I_TYPE)
        if(msmpeg4_decode_ext_header(s, buf_size) < 0) return -1;
    
    /* divx 5.01+ bistream reorder stuff */
    if(s->codec_id==CODEC_ID_MPEG4 && s->bitstream_buffer_size==0 && s->divx_version>=500){
        int current_pos= get_bits_count(&s->gb)>>3;

        if(   buf_size - current_pos > 5 
           && buf_size - current_pos < BITSTREAM_BUFFER_SIZE){
            int i;
            int startcode_found=0;
            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(startcode_found){
                memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);
                s->bitstream_buffer_size= buf_size - current_pos;
            }
        }
    }

    if(s->error_resilience){
        int error=0, num_end_markers=0;
        for(i=0; i<s->mb_num; i++){
            int status= s->error_status_table[i];
#if 0
            if(i%s->mb_width == 0) printf("\n");
            printf("%2X ", status); 
#endif
            if(status==0) continue;

            if(status&(DC_ERROR|AC_ERROR|MV_ERROR))
                error=1;
            if(status&VP_START){
                if(num_end_markers) 
                    error=1;
                num_end_markers=3;
            }
            if(status&AC_END)
                num_end_markers--;
            if(status&DC_END)
                num_end_markers--;
            if(status&MV_END)
                num_end_markers--;
        }
        if(num_end_markers || error){
            fprintf(stderr, "concealing errors\n");
//printf("type:%d\n", s->pict_type);
            ff_error_resilience(s);
        }
    }

    MPV_frame_end(s);
#if 0 //dirty show MVs, we should export the MV tables and write a filter to show them
{
  int mb_y;
  s->has_b_frames=1;
  for(mb_y=0; mb_y<s->mb_height; mb_y++){
    int mb_x;
    int y= mb_y*16 + 8;
    for(mb_x=0; mb_x<s->mb_width; mb_x++){
      int x= mb_x*16 + 8;
      uint8_t *ptr= s->last_picture[0];
      int xy= 1 + mb_x*2 + (mb_y*2 + 1)*(s->mb_width*2 + 2);
      int mx= (s->motion_val[xy][0]>>1) + x;
      int my= (s->motion_val[xy][1]>>1) + y;
      int i;
      int max;

      if(mx<0) mx=0;
      if(my<0) my=0;
      if(mx>=s->width)  mx= s->width -1;
      if(my>=s->height) my= s->height-1;
      max= ABS(mx-x);
      if(ABS(my-y) > max) max= ABS(my-y);
      /* the ugliest linedrawing routine ... */
      for(i=0; i<max; i++){
        int x1= x + (mx-x)*i/max;
        int y1= y + (my-y)*i/max;
        ptr[y1*s->linesize + x1]+=100;
      }
      ptr[y*s->linesize + x]+=100;
      s->mbskip_table[mb_x + mb_y*s->mb_width]=0;
    }
  }

}
#endif    
    if(s->pict_type==B_TYPE || (!s->has_b_frames)){
        pict->data[0] = s->current_picture[0];
        pict->data[1] = s->current_picture[1];
        pict->data[2] = s->current_picture[2];
    } else {
        pict->data[0] = s->last_picture[0];
        pict->data[1] = s->last_picture[1];
        pict->data[2] = s->last_picture[2];
    }
    pict->linesize[0] = s->linesize;
    pict->linesize[1] = s->uvlinesize;
    pict->linesize[2] = s->uvlinesize;

    avctx->quality = s->qscale;

    /* Return the Picture timestamp as the frame number */
    /* we substract 1 because it is added on utils.c    */
    avctx->frame_number = s->picture_number - 1;

    /* dont output the last pic after seeking 
       note we allready added +1 for the current pix in MPV_frame_end(s) */
    if(s->num_available_buffers>=2 || (!s->has_b_frames))
        *data_size = sizeof(AVPicture);
#ifdef PRINT_FRAME_TIME
printf("%Ld\n", rdtsc()-time);
#endif
    return get_consumed_bytes(s, buf_size);
}

AVCodec mpeg4_decoder = {
    "mpeg4",
    CODEC_TYPE_VIDEO,
    CODEC_ID_MPEG4,
    sizeof(MpegEncContext),
    h263_decode_init,
    NULL,
    h263_decode_end,
    h263_decode_frame,
    CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED,
};

AVCodec h263_decoder = {
    "h263",
    CODEC_TYPE_VIDEO,
    CODEC_ID_H263,
    sizeof(MpegEncContext),
    h263_decode_init,
    NULL,
    h263_decode_end,
    h263_decode_frame,
    CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
};

AVCodec msmpeg4v1_decoder = {
    "msmpeg4v1",
    CODEC_TYPE_VIDEO,
    CODEC_ID_MSMPEG4V1,
    sizeof(MpegEncContext),
    h263_decode_init,
    NULL,
    h263_decode_end,
    h263_decode_frame,
    CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
};

AVCodec msmpeg4v2_decoder = {
    "msmpeg4v2",
    CODEC_TYPE_VIDEO,
    CODEC_ID_MSMPEG4V2,
    sizeof(MpegEncContext),
    h263_decode_init,
    NULL,
    h263_decode_end,
    h263_decode_frame,
    CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
};

AVCodec msmpeg4v3_decoder = {
    "msmpeg4",
    CODEC_TYPE_VIDEO,
    CODEC_ID_MSMPEG4V3,
    sizeof(MpegEncContext),
    h263_decode_init,
    NULL,
    h263_decode_end,
    h263_decode_frame,
    CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
};

AVCodec wmv1_decoder = {
    "wmv1",
    CODEC_TYPE_VIDEO,
    CODEC_ID_WMV1,
    sizeof(MpegEncContext),
    h263_decode_init,
    NULL,
    h263_decode_end,
    h263_decode_frame,
    CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
};

AVCodec wmv2_decoder = {
    "wmv2",
    CODEC_TYPE_VIDEO,
    CODEC_ID_WMV2,
    sizeof(MpegEncContext),
    h263_decode_init,
    NULL,
    h263_decode_end,
    h263_decode_frame,
    CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
};

AVCodec h263i_decoder = {
    "h263i",
    CODEC_TYPE_VIDEO,
    CODEC_ID_H263I,
    sizeof(MpegEncContext),
    h263_decode_init,
    NULL,
    h263_decode_end,
    h263_decode_frame,
    CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
};