error_resilience.c

This the source release kit for the following system configuration(s): - AMD Alchemy(TM) DBAu1200(

/*
 * Error resilience / concealment
 *
 * Copyright (c) 2002-2004 Michael Niedermayer <[e-mail]>
 *
 * 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 error_resilience.c
 * Error resilience / concealment.
 */

#include <limits.h>

#include "avcodec.h"
#include "dsputil.h"
#include "mpegvideo.h"
#include "common.h"

/**
 * adds a slice.
 * @param endx x component of the last macroblock, can be -1 for the last of the previous line
 * @param status the status at the end (MV_END, AC_ERROR, ...), it is assumed that no earlier end or
 *               error of the same type occured
 */
void ff_er_add_slice(MpegEncContext *s, int startx, int starty, int endx, int endy, int status){
    const int start_i= clip(startx + starty * s->mb_width    , 0, s->mb_num-1);
    const int end_i  = clip(endx   + endy   * s->mb_width    , 0, s->mb_num);
    const int start_xy= s->mb_index2xy[start_i];
    const int end_xy  = s->mb_index2xy[end_i];
    int mask= -1;

    if(!s->error_resilience) return;

    mask &= ~VP_START;
    if(status & (AC_ERROR|AC_END)){
        mask &= ~(AC_ERROR|AC_END);
        s->error_count -= end_i - start_i + 1;
    }
    if(status & (DC_ERROR|DC_END)){
        mask &= ~(DC_ERROR|DC_END);
        s->error_count -= end_i - start_i + 1;
    }
    if(status & (MV_ERROR|MV_END)){
        mask &= ~(MV_ERROR|MV_END);
        s->error_count -= end_i - start_i + 1;
    }

    if(status & (AC_ERROR|DC_ERROR|MV_ERROR)) s->error_count= INT_MAX;

    if(mask == ~0x7F){
        memset(&s->error_status_table[start_xy], 0, (end_xy - start_xy) * sizeof(uint8_t));
    }else{
        int i;
        for(i=start_xy; i<end_xy; i++){
            s->error_status_table[ i ] &= mask;
        }
    }

    if(end_i == s->mb_num)
        s->error_count= INT_MAX;
    else{
        s->error_status_table[end_xy] &= mask;
        s->error_status_table[end_xy] |= status;
    }

    s->error_status_table[start_xy] |= VP_START;

    if(start_xy > 0 && s->avctx->skip_top*s->mb_width < start_i){
        int prev_status= s->error_status_table[ s->mb_index2xy[start_i - 1] ];

        prev_status &= ~ VP_START;
        if(prev_status != (MV_END|DC_END|AC_END)) s->error_count= INT_MAX;
    }
}