/*
 * H.263/MPEG-4 backend for encoder and decoder
 * Copyright (c) 2000,2001 Fabrice Bellard
 * H.263+ support.
 * Copyright (c) 2001 Juan J. Sierralta P
 * 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
 * H.263/MPEG-4 codec.
 */

#include "libavutil/thread.h"
#include "mpegvideo.h"
#include "h263.h"
#include "h263data.h"
#include "h263dsp.h"
#include "idctdsp.h"
#include "mathops.h"
#include "mpegpicture.h"
#include "mpegutils.h"
#include "rl.h"

static av_cold void h263_init_rl_inter(void)
{
    static uint8_t h263_rl_inter_table[2][2 * MAX_RUN + MAX_LEVEL + 3];
    ff_rl_init(&ff_h263_rl_inter, h263_rl_inter_table);
}

av_cold void ff_h263_init_rl_inter(void)
{
    static AVOnce init_static_once = AV_ONCE_INIT;
    ff_thread_once(&init_static_once, h263_init_rl_inter);
}

void ff_h263_update_motion_val(MpegEncContext * s){
    const int mb_xy = s->mb_y * s->mb_stride + s->mb_x;
               //FIXME a lot of that is only needed for !low_delay
    const int wrap = s->b8_stride;
    const int xy = s->block_index[0];

    if(s->mv_type != MV_TYPE_8X8){
        int motion_x, motion_y;
        if (s->mb_intra) {
            motion_x = 0;
            motion_y = 0;
        } else if (s->mv_type == MV_TYPE_16X16) {
            motion_x = s->mv[0][0][0];
            motion_y = s->mv[0][0][1];
        } else /*if (s->mv_type == MV_TYPE_FIELD)*/ {
            int i;
            motion_x = s->mv[0][0][0] + s->mv[0][1][0];
            motion_y = s->mv[0][0][1] + s->mv[0][1][1];
            motion_x = (motion_x>>1) | (motion_x&1);
            for(i=0; i<2; i++){
                s->p_field_mv_table[i][0][mb_xy][0]= s->mv[0][i][0];
                s->p_field_mv_table[i][0][mb_xy][1]= s->mv[0][i][1];
            }
            s->cur_pic.ref_index[0][4*mb_xy    ] =
            s->cur_pic.ref_index[0][4*mb_xy + 1] = s->field_select[0][0];
            s->cur_pic.ref_index[0][4*mb_xy + 2] =
            s->cur_pic.ref_index[0][4*mb_xy + 3] = s->field_select[0][1];
        }

        /* no update if 8X8 because it has been done during parsing */
        s->cur_pic.motion_val[0][xy][0]            = motion_x;
        s->cur_pic.motion_val[0][xy][1]            = motion_y;
        s->cur_pic.motion_val[0][xy + 1][0]        = motion_x;
        s->cur_pic.motion_val[0][xy + 1][1]        = motion_y;
        s->cur_pic.motion_val[0][xy + wrap][0]     = motion_x;
        s->cur_pic.motion_val[0][xy + wrap][1]     = motion_y;
        s->cur_pic.motion_val[0][xy + 1 + wrap][0] = motion_x;
        s->cur_pic.motion_val[0][xy + 1 + wrap][1] = motion_y;
    }
}

void ff_h263_loop_filter(MpegEncContext * s){
    int qp_c;
    const int linesize  = s->linesize;
    const int uvlinesize= s->uvlinesize;
    const int xy = s->mb_y * s->mb_stride + s->mb_x;
    uint8_t *dest_y = s->dest[0];
    uint8_t *dest_cb= s->dest[1];
    uint8_t *dest_cr= s->dest[2];

    /*
       Diag Top
       Left Center
    */
    if (!IS_SKIP(s->cur_pic.mb_type[xy])) {
        qp_c= s->qscale;
        s->h263dsp.h263_v_loop_filter(dest_y + 8 * linesize,     linesize, qp_c);
        s->h263dsp.h263_v_loop_filter(dest_y + 8 * linesize + 8, linesize, qp_c);
    }else
        qp_c= 0;

    if(s->mb_y){
        int qp_dt, qp_tt, qp_tc;

        if (IS_SKIP(s->cur_pic.mb_type[xy - s->mb_stride]))
            qp_tt=0;
        else
            qp_tt = s->cur_pic.qscale_table[xy - s->mb_stride];

        if(qp_c)
            qp_tc= qp_c;
        else
            qp_tc= qp_tt;

        if(qp_tc){
            const int chroma_qp= s->chroma_qscale_table[qp_tc];
            s->h263dsp.h263_v_loop_filter(dest_y,     linesize, qp_tc);
            s->h263dsp.h263_v_loop_filter(dest_y + 8, linesize, qp_tc);

            s->h263dsp.h263_v_loop_filter(dest_cb, uvlinesize, chroma_qp);
            s->h263dsp.h263_v_loop_filter(dest_cr, uvlinesize, chroma_qp);
        }

        if(qp_tt)
            s->h263dsp.h263_h_loop_filter(dest_y - 8 * linesize + 8, linesize, qp_tt);

        if(s->mb_x){
            if (qp_tt || IS_SKIP(s->cur_pic.mb_type[xy - 1 - s->mb_stride]))
                qp_dt= qp_tt;
            else
                qp_dt = s->cur_pic.qscale_table[xy - 1 - s->mb_stride];

            if(qp_dt){
                const int chroma_qp= s->chroma_qscale_table[qp_dt];
                s->h263dsp.h263_h_loop_filter(dest_y  - 8 * linesize,   linesize,   qp_dt);
                s->h263dsp.h263_h_loop_filter(dest_cb - 8 * uvlinesize, uvlinesize, chroma_qp);
                s->h263dsp.h263_h_loop_filter(dest_cr - 8 * uvlinesize, uvlinesize, chroma_qp);
            }
        }
    }

    if(qp_c){
        s->h263dsp.h263_h_loop_filter(dest_y + 8, linesize, qp_c);
        if(s->mb_y + 1 == s->mb_height)
            s->h263dsp.h263_h_loop_filter(dest_y + 8 * linesize + 8, linesize, qp_c);
    }

    if(s->mb_x){
        int qp_lc;
        if (qp_c || IS_SKIP(s->cur_pic.mb_type[xy - 1]))
            qp_lc= qp_c;
        else
            qp_lc = s->cur_pic.qscale_table[xy - 1];

        if(qp_lc){
            s->h263dsp.h263_h_loop_filter(dest_y, linesize, qp_lc);
            if(s->mb_y + 1 == s->mb_height){
                const int chroma_qp= s->chroma_qscale_table[qp_lc];
                s->h263dsp.h263_h_loop_filter(dest_y + 8 * linesize, linesize, qp_lc);
                s->h263dsp.h263_h_loop_filter(dest_cb, uvlinesize, chroma_qp);
                s->h263dsp.h263_h_loop_filter(dest_cr, uvlinesize, chroma_qp);
            }
        }
    }
}

int16_t *ff_h263_pred_motion(MpegEncContext * s, int block, int dir,
                             int *px, int *py)
{
    int wrap;
    int16_t *A, *B, *C, (*mot_val)[2];
    static const int off[4]= {2, 1, 1, -1};

    wrap = s->b8_stride;
    mot_val = s->cur_pic.motion_val[dir] + s->block_index[block];

    A = mot_val[ - 1];
    /* special case for first (slice) line */
    if (s->first_slice_line && block<3) {
        // we can't just change some MVs to simulate that as we need them for the B-frames (and ME)
        // and if we ever support non rectangular objects than we need to do a few ifs here anyway :(
        if(block==0){ //most common case
            if(s->mb_x  == s->resync_mb_x){ //rare
                *px= *py = 0;
            }else if(s->mb_x + 1 == s->resync_mb_x && s->h263_pred){ //rare
                C = mot_val[off[block] - wrap];
                if(s->mb_x==0){
                    *px = C[0];
                    *py = C[1];
                }else{
                    *px = mid_pred(A[0], 0, C[0]);
                    *py = mid_pred(A[1], 0, C[1]);
                }
            }else{
                *px = A[0];
                *py = A[1];
            }
        }else if(block==1){
            if(s->mb_x + 1 == s->resync_mb_x && s->h263_pred){ //rare
                C = mot_val[off[block] - wrap];
                *px = mid_pred(A[0], 0, C[0]);
                *py = mid_pred(A[1], 0, C[1]);
            }else{
                *px = A[0];
                *py = A[1];
            }
        }else{ /* block==2*/
            B = mot_val[ - wrap];
            C = mot_val[off[block] - wrap];
            if(s->mb_x == s->resync_mb_x) //rare
                A[0]=A[1]=0;

            *px = mid_pred(A[0], B[0], C[0]);
            *py = mid_pred(A[1], B[1], C[1]);
        }
    } else {
        B = mot_val[ - wrap];
        C = mot_val[off[block] - wrap];
        *px = mid_pred(A[0], B[0], C[0]);
        *py = mid_pred(A[1], B[1], C[1]);
    }
    return *mot_val;
}
