FFmpeg/libavcodec/motion_est.c

/*
 * Motion estimation 
 * Copyright (c) 2000,2001 Gerard Lantau.
 * 
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * new Motion Estimation (X1/EPZS) by Michael Niedermayer <michaelni@gmx.at>
 */
#include <stdlib.h>
#include <stdio.h>
#include "avcodec.h"
#include "dsputil.h"
#include "mpegvideo.h"

#define ABS(a) ((a)>0 ? (a) : -(a))
#define MAX(a,b) ((a) > (b) ? (a) : (b))
#define INTER_BIAS	257

static int halfpel_motion_search(MpegEncContext * s,
				  int *mx_ptr, int *my_ptr, int dmin,
				  int xmin, int ymin, int xmax, int ymax,
                                  int pred_x, int pred_y, uint8_t *ref_picture);

static int pix_sum(UINT8 * pix, int line_size)
{
    int s, i, j;

    s = 0;
    for (i = 0; i < 16; i++) {
	for (j = 0; j < 16; j += 8) {
	    s += pix[0];
	    s += pix[1];
	    s += pix[2];
	    s += pix[3];
	    s += pix[4];
	    s += pix[5];
	    s += pix[6];
	    s += pix[7];
	    pix += 8;
	}
	pix += line_size - 16;
    }
    return s;
}

static int pix_dev(UINT8 * pix, int line_size, int mean)
{
    int s, i, j;

    s = 0;
    for (i = 0; i < 16; i++) {
	for (j = 0; j < 16; j += 8) {
	    s += ABS(pix[0]-mean);
	    s += ABS(pix[1]-mean);
	    s += ABS(pix[2]-mean);
	    s += ABS(pix[3]-mean);
	    s += ABS(pix[4]-mean);
	    s += ABS(pix[5]-mean);
	    s += ABS(pix[6]-mean);
	    s += ABS(pix[7]-mean);
	    pix += 8;
	}
	pix += line_size - 16;
    }
    return s;
}

static int pix_norm1(UINT8 * pix, int line_size)
{
    int s, i, j;
    UINT32 *sq = squareTbl + 256;

    s = 0;
    for (i = 0; i < 16; i++) {
	for (j = 0; j < 16; j += 8) {
	    s += sq[pix[0]];
	    s += sq[pix[1]];
	    s += sq[pix[2]];
	    s += sq[pix[3]];
	    s += sq[pix[4]];
	    s += sq[pix[5]];
	    s += sq[pix[6]];
	    s += sq[pix[7]];
	    pix += 8;
	}
	pix += line_size - 16;
    }
    return s;
}

static int pix_norm(UINT8 * pix1, UINT8 * pix2, int line_size)
{
    int s, i, j;
    UINT32 *sq = squareTbl + 256;

    s = 0;
    for (i = 0; i < 16; i++) {
	for (j = 0; j < 16; j += 8) {
	    s += sq[pix1[0] - pix2[0]];
	    s += sq[pix1[1] - pix2[1]];
	    s += sq[pix1[2] - pix2[2]];
	    s += sq[pix1[3] - pix2[3]];
	    s += sq[pix1[4] - pix2[4]];
	    s += sq[pix1[5] - pix2[5]];
	    s += sq[pix1[6] - pix2[6]];
	    s += sq[pix1[7] - pix2[7]];
	    pix1 += 8;
	    pix2 += 8;
	}
	pix1 += line_size - 16;
	pix2 += line_size - 16;
    }
    return s;
}

static void no_motion_search(MpegEncContext * s,
			     int *mx_ptr, int *my_ptr)
{
    *mx_ptr = 16 * s->mb_x;
    *my_ptr = 16 * s->mb_y;
}

static int full_motion_search(MpegEncContext * s,
                              int *mx_ptr, int *my_ptr, int range,
                              int xmin, int ymin, int xmax, int ymax, uint8_t *ref_picture)
{
    int x1, y1, x2, y2, xx, yy, x, y;
    int mx, my, dmin, d;
    UINT8 *pix;

    xx = 16 * s->mb_x;
    yy = 16 * s->mb_y;
    x1 = xx - range + 1;	/* we loose one pixel to avoid boundary pb with half pixel pred */
    if (x1 < xmin)
	x1 = xmin;
    x2 = xx + range - 1;
    if (x2 > xmax)
	x2 = xmax;
    y1 = yy - range + 1;
    if (y1 < ymin)
	y1 = ymin;
    y2 = yy + range - 1;
    if (y2 > ymax)
	y2 = ymax;
    pix = s->new_picture[0] + (yy * s->linesize) + xx;
    dmin = 0x7fffffff;
    mx = 0;
    my = 0;
    for (y = y1; y <= y2; y++) {
	for (x = x1; x <= x2; x++) {
	    d = pix_abs16x16(pix, ref_picture + (y * s->linesize) + x,
			     s->linesize);
	    if (d < dmin ||
		(d == dmin &&
		 (abs(x - xx) + abs(y - yy)) <
		 (abs(mx - xx) + abs(my - yy)))) {
		dmin = d;
		mx = x;
		my = y;
	    }
	}
    }

    *mx_ptr = mx;
    *my_ptr = my;

#if 0
    if (*mx_ptr < -(2 * range) || *mx_ptr >= (2 * range) ||
	*my_ptr < -(2 * range) || *my_ptr >= (2 * range)) {
	fprintf(stderr, "error %d %d\n", *mx_ptr, *my_ptr);
    }
#endif
    return dmin;
}


static int log_motion_search(MpegEncContext * s,
                             int *mx_ptr, int *my_ptr, int range,
                             int xmin, int ymin, int xmax, int ymax, uint8_t *ref_picture)
{
    int x1, y1, x2, y2, xx, yy, x, y;
    int mx, my, dmin, d;
    UINT8 *pix;

    xx = s->mb_x << 4;
    yy = s->mb_y << 4;

    /* Left limit */
    x1 = xx - range;
    if (x1 < xmin)
	x1 = xmin;

    /* Right limit */
    x2 = xx + range;
    if (x2 > xmax)
	x2 = xmax;

    /* Upper limit */
    y1 = yy - range;
    if (y1 < ymin)
	y1 = ymin;

    /* Lower limit */
    y2 = yy + range;
    if (y2 > ymax)
	y2 = ymax;

    pix = s->new_picture[0] + (yy * s->linesize) + xx;
    dmin = 0x7fffffff;
    mx = 0;
    my = 0;

    do {
	for (y = y1; y <= y2; y += range) {
	    for (x = x1; x <= x2; x += range) {
		d = pix_abs16x16(pix, ref_picture + (y * s->linesize) + x, s->linesize);
		if (d < dmin || (d == dmin && (abs(x - xx) + abs(y - yy)) < (abs(mx - xx) + abs(my - yy)))) {
		    dmin = d;
		    mx = x;
		    my = y;
		}
	    }
	}

	range = range >> 1;

	x1 = mx - range;
	if (x1 < xmin)
	    x1 = xmin;

	x2 = mx + range;
	if (x2 > xmax)
	    x2 = xmax;

	y1 = my - range;
	if (y1 < ymin)
	    y1 = ymin;

	y2 = my + range;
	if (y2 > ymax)
	    y2 = ymax;

    } while (range >= 1);

#ifdef DEBUG
    fprintf(stderr, "log       - MX: %d\tMY: %d\n", mx, my);
#endif
    *mx_ptr = mx;
    *my_ptr = my;
    return dmin;
}

static int phods_motion_search(MpegEncContext * s,
                               int *mx_ptr, int *my_ptr, int range,
                               int xmin, int ymin, int xmax, int ymax, uint8_t *ref_picture)
{
    int x1, y1, x2, y2, xx, yy, x, y, lastx, d;
    int mx, my, dminx, dminy;
    UINT8 *pix;

    xx = s->mb_x << 4;
    yy = s->mb_y << 4;

    /* Left limit */
    x1 = xx - range;
    if (x1 < xmin)
	x1 = xmin;

    /* Right limit */
    x2 = xx + range;
    if (x2 > xmax)
	x2 = xmax;

    /* Upper limit */
    y1 = yy - range;
    if (y1 < ymin)
	y1 = ymin;

    /* Lower limit */
    y2 = yy + range;
    if (y2 > ymax)
	y2 = ymax;

    pix = s->new_picture[0] + (yy * s->linesize) + xx;
    mx = 0;
    my = 0;

    x = xx;
    y = yy;
    do {
        dminx = 0x7fffffff;
        dminy = 0x7fffffff;

	lastx = x;
	for (x = x1; x <= x2; x += range) {
	    d = pix_abs16x16(pix, ref_picture + (y * s->linesize) + x, s->linesize);
	    if (d < dminx || (d == dminx && (abs(x - xx) + abs(y - yy)) < (abs(mx - xx) + abs(my - yy)))) {
		dminx = d;
		mx = x;
	    }
	}

	x = lastx;
	for (y = y1; y <= y2; y += range) {
	    d = pix_abs16x16(pix, ref_picture + (y * s->linesize) + x, s->linesize);
	    if (d < dminy || (d == dminy && (abs(x - xx) + abs(y - yy)) < (abs(mx - xx) + abs(my - yy)))) {
		dminy = d;
		my = y;
	    }
	}

	range = range >> 1;

	x = mx;
	y = my;
	x1 = mx - range;
	if (x1 < xmin)
	    x1 = xmin;

	x2 = mx + range;
	if (x2 > xmax)
	    x2 = xmax;

	y1 = my - range;
	if (y1 < ymin)
	    y1 = ymin;

	y2 = my + range;
	if (y2 > ymax)
	    y2 = ymax;

    } while (range >= 1);

#ifdef DEBUG
    fprintf(stderr, "phods     - MX: %d\tMY: %d\n", mx, my);
#endif

    /* half pixel search */
    *mx_ptr = mx;
    *my_ptr = my;
    return dminy;
}


#define Z_THRESHOLD 256

#define CHECK_MV(x,y)\
{\
    d = pix_abs16x16(new_pic, old_pic + (x) + (y)*pic_stride, pic_stride);\
    d += (mv_penalty[((x)<<shift)-pred_x] + mv_penalty[((y)<<shift)-pred_y])*quant;\
    if(d<dmin){\
        best[0]=x;\
        best[1]=y;\
        dmin=d;\
    }\
}

#define CHECK_MV_DIR(x,y,new_dir)\
{\
    d = pix_abs16x16(new_pic, old_pic + (x) + (y)*pic_stride, pic_stride);\
    d += (mv_penalty[((x)<<shift)-pred_x] + mv_penalty[((y)<<shift)-pred_y])*quant;\
    if(d<dmin){\
        best[0]=x;\
        best[1]=y;\
        dmin=d;\
        next_dir= new_dir;\
    }\
}

#define CHECK_MV4(x,y)\
{\
    d = pix_abs8x8(new_pic, old_pic + (x) + (y)*pic_stride, pic_stride);\
    d += (mv_penalty[((x)<<shift)-pred_x] + mv_penalty[((y)<<shift)-pred_y])*quant;\
    if(d<dmin){\
        best[0]=x;\
        best[1]=y;\
        dmin=d;\
    }\
}

#define CHECK_MV4_DIR(x,y,new_dir)\
{\
    d = pix_abs8x8(new_pic, old_pic + (x) + (y)*pic_stride, pic_stride);\
    d += (mv_penalty[((x)<<shift)-pred_x] + mv_penalty[((y)<<shift)-pred_y])*quant;\
    if(d<dmin){\
        best[0]=x;\
        best[1]=y;\
        dmin=d;\
        next_dir= new_dir;\
    }\
}


#define check(x,y,S,v)\
if( (x)<(xmin<<(S)) ) printf("%d %d %d %d xmin" #v, (x), (y), s->mb_x, s->mb_y);\
if( (x)>(xmax<<(S)) ) printf("%d %d %d %d xmax" #v, (x), (y), s->mb_x, s->mb_y);\
if( (y)<(ymin<<(S)) ) printf("%d %d %d %d ymin" #v, (x), (y), s->mb_x, s->mb_y);\
if( (y)>(ymax<<(S)) ) printf("%d %d %d %d ymax" #v, (x), (y), s->mb_x, s->mb_y);\


static inline int small_diamond_search(MpegEncContext * s, int *best, int dmin,
                                       UINT8 *new_pic, UINT8 *old_pic, int pic_stride,
                                       int pred_x, int pred_y, UINT16 *mv_penalty, int quant,
                                       int xmin, int ymin, int xmax, int ymax, int shift)
{
    int next_dir=-1;

    for(;;){
        int d;
        const int dir= next_dir;
        const int x= best[0];
        const int y= best[1];
        next_dir=-1;

//printf("%d", dir);
        if(dir!=2 && x>xmin) CHECK_MV_DIR(x-1, y  , 0)
        if(dir!=3 && y>ymin) CHECK_MV_DIR(x  , y-1, 1)
        if(dir!=0 && x<xmax) CHECK_MV_DIR(x+1, y  , 2)
        if(dir!=1 && y<ymax) CHECK_MV_DIR(x  , y+1, 3)

        if(next_dir==-1){
            return dmin;
        }
    }

/*    for(;;){
        int d;
        const int x= best[0];
        const int y= best[1];
        const int last_min=dmin;
        if(x>xmin) CHECK_MV(x-1, y  )
        if(y>xmin) CHECK_MV(x  , y-1)
        if(x<xmax) CHECK_MV(x+1, y  )
        if(y<xmax) CHECK_MV(x  , y+1)
        if(x>xmin && y>ymin) CHECK_MV(x-1, y-1)
        if(x>xmin && y<ymax) CHECK_MV(x-1, y+1)
        if(x<xmax && y>ymin) CHECK_MV(x+1, y-1)
        if(x<xmax && y<ymax) CHECK_MV(x+1, y+1)
        if(x-1>xmin) CHECK_MV(x-2, y  )
        if(y-1>xmin) CHECK_MV(x  , y-2)
        if(x+1<xmax) CHECK_MV(x+2, y  )
        if(y+1<xmax) CHECK_MV(x  , y+2)
        if(x-1>xmin && y-1>ymin) CHECK_MV(x-2, y-2)
        if(x-1>xmin && y+1<ymax) CHECK_MV(x-2, y+2)
        if(x+1<xmax && y-1>ymin) CHECK_MV(x+2, y-2)
        if(x+1<xmax && y+1<ymax) CHECK_MV(x+2, y+2)
        if(dmin==last_min) return dmin;
    }
    */
}

static inline int small_diamond_search4MV(MpegEncContext * s, int *best, int dmin,
                                       UINT8 *new_pic, UINT8 *old_pic, int pic_stride,
                                       int pred_x, int pred_y, UINT16 *mv_penalty, int quant,
                                       int xmin, int ymin, int xmax, int ymax, int shift)
{
    int next_dir=-1;

    for(;;){
        int d;
        const int dir= next_dir;
        const int x= best[0];
        const int y= best[1];
        next_dir=-1;

//printf("%d", dir);
        if(dir!=2 && x>xmin) CHECK_MV4_DIR(x-1, y  , 0)
        if(dir!=3 && y>ymin) CHECK_MV4_DIR(x  , y-1, 1)
        if(dir!=0 && x<xmax) CHECK_MV4_DIR(x+1, y  , 2)
        if(dir!=1 && y<ymax) CHECK_MV4_DIR(x  , y+1, 3)

        if(next_dir==-1){
            return dmin;
        }
    }
}

static inline int snake_search(MpegEncContext * s, int *best, int dmin,
                                       UINT8 *new_pic, UINT8 *old_pic, int pic_stride,
                                       int pred_x, int pred_y, UINT16 *mv_penalty, int quant,
                                       int xmin, int ymin, int xmax, int ymax, int shift)
{
    int dir=0;
    int c=1;
    static int x_dir[8]= {1,1,0,-1,-1,-1, 0, 1};
    static int y_dir[8]= {0,1,1, 1, 0,-1,-1,-1};
    int fails=0;
    int last_d[2]={dmin, dmin};

/*static int good=0;
static int bad=0;
static int point=0;

point++;
if(256*256*256*64%point==0)
{
    printf("%d %d %d\n", good, bad, point);
}*/

    for(;;){
        int x= best[0];
        int y= best[1];
        int d;
        x+=x_dir[dir];
        y+=y_dir[dir];
        if(x>=xmin && x<=xmax && y>=ymin && y<=ymax){
            d = pix_abs16x16(new_pic, old_pic + (x) + (y)*pic_stride, pic_stride);
            d += (mv_penalty[((x)<<shift)-pred_x] + mv_penalty[((y)<<shift)-pred_y])*quant;
        }else{
            d = dmin + 10000; //FIXME smarter boundary handling
        }
        if(d<dmin){
            best[0]=x;
            best[1]=y;
            dmin=d;

            if(last_d[1] - last_d[0] > last_d[0] - d) c= -c;
            dir+=c;

            fails=0;
//good++;
            last_d[1]=last_d[0];
            last_d[0]=d;
        }else{
//bad++;
            if(fails){
                if(fails>=3) return dmin;
            }else{
                c= -c;
            }
            dir+=c*2;
            fails++;
        }
        dir&=7;
    }
}

static int epzs_motion_search(MpegEncContext * s,
                             int *mx_ptr, int *my_ptr,
                             int P[5][2], int pred_x, int pred_y,
                             int xmin, int ymin, int xmax, int ymax, uint8_t * ref_picture)
{
    int best[2]={0, 0};
    int d, dmin; 
    UINT8 *new_pic, *old_pic;
    const int pic_stride= s->linesize;
    const int pic_xy= (s->mb_y*pic_stride + s->mb_x)*16;
    UINT16 *mv_penalty= s->mv_penalty[s->f_code] + MAX_MV; // f_code of the prev frame
    int quant= s->qscale; // qscale of the prev frame
    const int shift= 1+s->quarter_sample;

    new_pic = s->new_picture[0] + pic_xy;
    old_pic = ref_picture + pic_xy;
   
    dmin = pix_abs16x16(new_pic, old_pic, pic_stride);
    if(dmin<Z_THRESHOLD){
        *mx_ptr= 0;
        *my_ptr= 0;
//printf("Z");
        return dmin;
    }

    /* first line */
    if ((s->mb_y == 0 || s->first_slice_line || s->first_gob_line)) {
        CHECK_MV(P[1][0]>>shift, P[1][1]>>shift)
    }else{
        CHECK_MV(P[4][0]>>shift, P[4][1]>>shift)
        if(dmin<Z_THRESHOLD){
            *mx_ptr= P[4][0]>>shift;
            *my_ptr= P[4][1]>>shift;
//printf("M\n");
            return dmin;
        }
        CHECK_MV(P[1][0]>>shift, P[1][1]>>shift)
        CHECK_MV(P[2][0]>>shift, P[2][1]>>shift)
        CHECK_MV(P[3][0]>>shift, P[3][1]>>shift)
    }
    CHECK_MV(P[0][0]>>shift, P[0][1]>>shift)

//check(best[0],best[1],0, b0)
    if(s->me_method==ME_EPZS)
        dmin= small_diamond_search(s, best, dmin, new_pic, old_pic, pic_stride, 
                                   pred_x, pred_y, mv_penalty, quant, xmin, ymin, xmax, ymax, shift);
    else
        dmin=         snake_search(s, best, dmin, new_pic, old_pic, pic_stride, 
                                   pred_x, pred_y, mv_penalty, quant, xmin, ymin, xmax, ymax, shift);
//check(best[0],best[1],0, b1)
    *mx_ptr= best[0];
    *my_ptr= best[1];    

//    printf("%d %d %d \n", best[0], best[1], dmin);
    return dmin;
}

static int epzs_motion_search4(MpegEncContext * s, int block,
                             int *mx_ptr, int *my_ptr,
                             int P[6][2], int pred_x, int pred_y,
                             int xmin, int ymin, int xmax, int ymax, uint8_t *ref_picture)
{
    int best[2]={0, 0};
    int d, dmin; 
    UINT8 *new_pic, *old_pic;
    const int pic_stride= s->linesize;
    const int pic_xy= ((s->mb_y*2 + (block>>1))*pic_stride + s->mb_x*2 + (block&1))*8;
    UINT16 *mv_penalty= s->mv_penalty[s->f_code] + MAX_MV; // f_code of the prev frame
    int quant= s->qscale; // qscale of the prev frame
    const int shift= 1+s->quarter_sample;

    new_pic = s->new_picture[0] + pic_xy;
    old_pic = ref_picture + pic_xy;
   
    dmin = pix_abs8x8(new_pic, old_pic, pic_stride);

    /* first line */
    if ((s->mb_y == 0 || s->first_slice_line || s->first_gob_line) && block<2) {
        CHECK_MV4(P[1][0]>>shift, P[1][1]>>shift)
    }else{
        CHECK_MV4(P[4][0]>>shift, P[4][1]>>shift)
        if(dmin<Z_THRESHOLD){
            *mx_ptr= P[4][0]>>shift;
            *my_ptr= P[4][1]>>shift;
//printf("M\n");
            return dmin;
        }
        CHECK_MV4(P[1][0]>>shift, P[1][1]>>shift)
        CHECK_MV4(P[2][0]>>shift, P[2][1]>>shift)
        CHECK_MV4(P[3][0]>>shift, P[3][1]>>shift)
    }
    CHECK_MV4(P[0][0]>>shift, P[0][1]>>shift)
    CHECK_MV4(P[5][0]>>shift, P[5][1]>>shift)

//check(best[0],best[1],0, b0)
    dmin= small_diamond_search4MV(s, best, dmin, new_pic, old_pic, pic_stride, 
                                   pred_x, pred_y, mv_penalty, quant, xmin, ymin, xmax, ymax, shift);
//check(best[0],best[1],0, b1)
    *mx_ptr= best[0];
    *my_ptr= best[1];    

//    printf("%d %d %d \n", best[0], best[1], dmin);
    return dmin;
}

#define CHECK_HALF_MV(suffix, x, y) \
    d= pix_abs16x16_ ## suffix(pix, ptr+((x)>>1), s->linesize);\
    d += (mv_penalty[pen_x + x] + mv_penalty[pen_y + y])*quant;\
    if(d<dminh){\
        dminh= d;\
        mx= mx1 + x;\
        my= my1 + y;\
    }

#define CHECK_HALF_MV4(suffix, x, y) \
    d= pix_abs8x8_ ## suffix(pix, ptr+((x)>>1), s->linesize);\
    d += (mv_penalty[pen_x + x] + mv_penalty[pen_y + y])*quant;\
    if(d<dminh){\
        dminh= d;\
        mx= mx1 + x;\
        my= my1 + y;\
    }
    
/* The idea would be to make half pel ME after Inter/Intra decision to 
   save time. */
static inline int halfpel_motion_search(MpegEncContext * s,
				  int *mx_ptr, int *my_ptr, int dmin,
				  int xmin, int ymin, int xmax, int ymax,
                                  int pred_x, int pred_y, uint8_t *ref_picture)
{
    UINT16 *mv_penalty= s->mv_penalty[s->f_code] + MAX_MV; // f_code of the prev frame
    const int quant= s->qscale;
    int pen_x, pen_y;
    int mx, my, mx1, my1, d, xx, yy, dminh;
    UINT8 *pix, *ptr;

    mx = *mx_ptr;
    my = *my_ptr;
    ptr = ref_picture + (my * s->linesize) + mx;

    xx = 16 * s->mb_x;
    yy = 16 * s->mb_y;
    pix =  s->new_picture[0] + (yy * s->linesize) + xx;
    
    dminh = dmin;

    if (mx > xmin && mx < xmax && 
        my > ymin && my < ymax) {

        mx= mx1= 2*(mx - xx);
        my= my1= 2*(my - yy);
        if(dmin < Z_THRESHOLD && mx==0 && my==0){
            *mx_ptr = 0;
            *my_ptr = 0;
            return dmin;
        }
        
        pen_x= pred_x + mx;
        pen_y= pred_y + my;

        ptr-= s->linesize;
        CHECK_HALF_MV(xy2, -1, -1)
        CHECK_HALF_MV(y2 ,  0, -1)
        CHECK_HALF_MV(xy2, +1, -1)
        
        ptr+= s->linesize;
        CHECK_HALF_MV(x2 , -1,  0)
        CHECK_HALF_MV(x2 , +1,  0)
        CHECK_HALF_MV(xy2, -1, +1)
        CHECK_HALF_MV(y2 ,  0, +1)
        CHECK_HALF_MV(xy2, +1, +1)

    }else{
        mx= 2*(mx - xx);
        my= 2*(my - yy);
    }

    *mx_ptr = mx;
    *my_ptr = my;
    return dminh;
}

static inline void halfpel_motion_search4(MpegEncContext * s,
				  int *mx_ptr, int *my_ptr, int dmin,
				  int xmin, int ymin, int xmax, int ymax,
                                  int pred_x, int pred_y, int block_x, int block_y,
                                  uint8_t *ref_picture)
{
    UINT16 *mv_penalty= s->mv_penalty[s->f_code] + MAX_MV; // f_code of the prev frame
    const int quant= s->qscale;
    int pen_x, pen_y;
    int mx, my, mx1, my1, d, xx, yy, dminh;
    UINT8 *pix, *ptr;

    xx = 8 * block_x;
    yy = 8 * block_y;
    pix =  s->new_picture[0] + (yy * s->linesize) + xx;
    
    mx = *mx_ptr;
    my = *my_ptr;
    ptr = ref_picture + ((yy+my) * s->linesize) + xx + mx;

    dminh = dmin;

    if (mx > xmin && mx < xmax && 
        my > ymin && my < ymax) {

        mx= mx1= 2*mx;
        my= my1= 2*my;
        if(dmin < Z_THRESHOLD && mx==0 && my==0){
            *mx_ptr = 0;
            *my_ptr = 0;
            return;
        }
        
        pen_x= pred_x + mx;
        pen_y= pred_y + my;

        ptr-= s->linesize;
        CHECK_HALF_MV4(xy2, -1, -1)
        CHECK_HALF_MV4(y2 ,  0, -1)
        CHECK_HALF_MV4(xy2, +1, -1)
        
        ptr+= s->linesize;
        CHECK_HALF_MV4(x2 , -1,  0)
        CHECK_HALF_MV4(x2 , +1,  0)
        CHECK_HALF_MV4(xy2, -1, +1)
        CHECK_HALF_MV4(y2 ,  0, +1)
        CHECK_HALF_MV4(xy2, +1, +1)

    }else{
        mx*=2;
        my*=2;
    }

    *mx_ptr = mx;
    *my_ptr = my;
}

static inline void set_p_mv_tables(MpegEncContext * s, int mx, int my)
{
    const int xy= s->mb_x + 1 + (s->mb_y + 1)*(s->mb_width + 2);
    
    s->p_mv_table[xy][0] = mx;
    s->p_mv_table[xy][1] = my;

    /* has allready been set to the 4 MV if 4MV is done */
    if(!(s->flags&CODEC_FLAG_4MV)){
        int mot_xy= s->block_index[0];

        s->motion_val[mot_xy  ][0]= mx;
        s->motion_val[mot_xy  ][1]= my;
        s->motion_val[mot_xy+1][0]= mx;
        s->motion_val[mot_xy+1][1]= my;

        mot_xy += s->block_wrap[0];
        s->motion_val[mot_xy  ][0]= mx;
        s->motion_val[mot_xy  ][1]= my;
        s->motion_val[mot_xy+1][0]= mx;
        s->motion_val[mot_xy+1][1]= my;
    }
}

static inline void get_limits(MpegEncContext *s, int *range, int *xmin, int *ymin, int *xmax, int *ymax, int f_code)
{
    *range = 8 * (1 << (f_code - 1));
    /* XXX: temporary kludge to avoid overflow for msmpeg4 */
    if (s->out_format == FMT_H263 && !s->h263_msmpeg4)
	*range *= 2;

    if (s->unrestricted_mv) {
        *xmin = -16;
        *ymin = -16;
        if (s->h263_plus)
            *range *= 2;
        if(s->avctx==NULL || s->avctx->codec->id!=CODEC_ID_MPEG4){
            *xmax = s->mb_width*16;
            *ymax = s->mb_height*16;
        }else {
            /* XXX: dunno if this is correct but ffmpeg4 decoder wont like it otherwise 
	            (cuz the drawn edge isnt large enough))*/
            *xmax = s->width;
            *ymax = s->height;
        }
    } else {
        *xmin = 0;
        *ymin = 0;
        *xmax = s->mb_width*16 - 16;
        *ymax = s->mb_height*16 - 16;
    }
}

void ff_estimate_p_frame_motion(MpegEncContext * s,
                                int mb_x, int mb_y)
{
    UINT8 *pix, *ppix;
    int sum, varc, vard, mx, my, range, dmin, xx, yy;
    int xmin, ymin, xmax, ymax;
    int rel_xmin, rel_ymin, rel_xmax, rel_ymax;
    int pred_x=0, pred_y=0;
    int P[6][2];
    const int shift= 1+s->quarter_sample;
    int mb_type=0;
    uint8_t *ref_picture= s->last_picture[0];

    get_limits(s, &range, &xmin, &ymin, &xmax, &ymax, s->f_code);

    switch(s->me_method) {
    case ME_ZERO:
    default:
	no_motion_search(s, &mx, &my);
        dmin = 0;
        break;
    case ME_FULL:
	dmin = full_motion_search(s, &mx, &my, range, xmin, ymin, xmax, ymax, ref_picture);
        break;
    case ME_LOG:
	dmin = log_motion_search(s, &mx, &my, range / 2, xmin, ymin, xmax, ymax, ref_picture);
        break;
    case ME_PHODS:
	dmin = phods_motion_search(s, &mx, &my, range / 2, xmin, ymin, xmax, ymax, ref_picture);
        break;
    case ME_X1:
    case ME_EPZS:
       {
            const int mot_stride = s->block_wrap[0];
            const int mot_xy = s->block_index[0];

            rel_xmin= xmin - mb_x*16;
            rel_xmax= xmax - mb_x*16;
            rel_ymin= ymin - mb_y*16;
            rel_ymax= ymax - mb_y*16;

            P[0][0] = s->motion_val[mot_xy    ][0];
            P[0][1] = s->motion_val[mot_xy    ][1];
            P[1][0] = s->motion_val[mot_xy - 1][0];
            P[1][1] = s->motion_val[mot_xy - 1][1];
            if(P[1][0] > (rel_xmax<<shift)) P[1][0]= (rel_xmax<<shift);

            /* special case for first line */
            if ((mb_y == 0 || s->first_slice_line || s->first_gob_line)) {
                P[4][0] = P[1][0];
                P[4][1] = P[1][1];
            } else {
                P[2][0] = s->motion_val[mot_xy - mot_stride             ][0];
                P[2][1] = s->motion_val[mot_xy - mot_stride             ][1];
                P[3][0] = s->motion_val[mot_xy - mot_stride + 2         ][0];
                P[3][1] = s->motion_val[mot_xy - mot_stride + 2         ][1];
                if(P[2][1] > (rel_ymax<<shift)) P[2][1]= (rel_ymax<<shift);
                if(P[3][0] < (rel_xmin<<shift)) P[3][0]= (rel_xmin<<shift);
                if(P[3][1] > (rel_ymax<<shift)) P[3][1]= (rel_ymax<<shift);
        
                P[4][0]= mid_pred(P[1][0], P[2][0], P[3][0]);
                P[4][1]= mid_pred(P[1][1], P[2][1], P[3][1]);
            }
            if(s->out_format == FMT_H263){
                pred_x = P[4][0];
                pred_y = P[4][1];
            }else { /* mpeg1 at least */
                pred_x= P[1][0];
                pred_y= P[1][1];
            }
        }
        dmin = epzs_motion_search(s, &mx, &my, P, pred_x, pred_y, rel_xmin, rel_ymin, rel_xmax, rel_ymax, ref_picture);
 
        mx+= mb_x*16;
        my+= mb_y*16;
        break;
    }
    
    if(s->flags&CODEC_FLAG_4MV){
        int block;

        mb_type|= MB_TYPE_INTER4V;

        for(block=0; block<4; block++){
            int mx4, my4;
            int pred_x4, pred_y4;
            int dmin4;
            static const int off[4]= {2, 1, 1, -1};
            const int mot_stride = s->block_wrap[0];
            const int mot_xy = s->block_index[block];
            const int block_x= mb_x*2 + (block&1);
            const int block_y= mb_y*2 + (block>>1);

            const int rel_xmin4= xmin - block_x*8;
            const int rel_xmax4= xmax - block_x*8 + 8;
            const int rel_ymin4= ymin - block_y*8;
            const int rel_ymax4= ymax - block_y*8 + 8;

            P[0][0] = s->motion_val[mot_xy    ][0];
            P[0][1] = s->motion_val[mot_xy    ][1];
            P[1][0] = s->motion_val[mot_xy - 1][0];
            P[1][1] = s->motion_val[mot_xy - 1][1];
            if(P[1][0] > (rel_xmax4<<shift)) P[1][0]= (rel_xmax4<<shift);

            /* special case for first line */
            if ((mb_y == 0 || s->first_slice_line || s->first_gob_line) && block<2) {
                P[4][0] = P[1][0];
                P[4][1] = P[1][1];
            } else {
                P[2][0] = s->motion_val[mot_xy - mot_stride             ][0];
                P[2][1] = s->motion_val[mot_xy - mot_stride             ][1];
                P[3][0] = s->motion_val[mot_xy - mot_stride + off[block]][0];
                P[3][1] = s->motion_val[mot_xy - mot_stride + off[block]][1];
                if(P[2][1] > (rel_ymax4<<shift)) P[2][1]= (rel_ymax4<<shift);
                if(P[3][0] < (rel_xmin4<<shift)) P[3][0]= (rel_xmin4<<shift);
                if(P[3][0] > (rel_xmax4<<shift)) P[3][0]= (rel_xmax4<<shift);
                if(P[3][1] > (rel_ymax4<<shift)) P[3][1]= (rel_ymax4<<shift);
        
                P[4][0]= mid_pred(P[1][0], P[2][0], P[3][0]);
                P[4][1]= mid_pred(P[1][1], P[2][1], P[3][1]);
            }
            if(s->out_format == FMT_H263){
                pred_x4 = P[4][0];
                pred_y4 = P[4][1];
            }else { /* mpeg1 at least */
                pred_x4= P[1][0];
                pred_y4= P[1][1];
            }
            P[5][0]= mx - mb_x*16;
            P[5][1]= my - mb_y*16;

            dmin4 = epzs_motion_search4(s, block, &mx4, &my4, P, pred_x4, pred_y4, rel_xmin4, rel_ymin4, rel_xmax4, rel_ymax4, ref_picture);

            halfpel_motion_search4(s, &mx4, &my4, dmin4, rel_xmin4, rel_ymin4, rel_xmax4, rel_ymax4, 
                                   pred_x4, pred_y4, block_x, block_y, ref_picture);
     
            s->motion_val[ s->block_index[block] ][0]= mx4;
            s->motion_val[ s->block_index[block] ][1]= my4;
        }
    }

    /* intra / predictive decision */
    xx = mb_x * 16;
    yy = mb_y * 16;

    pix = s->new_picture[0] + (yy * s->linesize) + xx;
    /* At this point (mx,my) are full-pell and the absolute displacement */
    ppix = ref_picture + (my * s->linesize) + mx;
    
    sum = pix_sum(pix, s->linesize);
#if 0
    varc = pix_dev(pix, s->linesize, (sum+128)>>8) + INTER_BIAS;
    vard = pix_abs16x16(pix, ppix, s->linesize);
#else
    sum= (sum+8)>>4;
    varc = ((pix_norm1(pix, s->linesize) - sum*sum + 128 + 500)>>8);
    vard = (pix_norm(pix, ppix, s->linesize)+128)>>8;
#endif

    s->mb_var[s->mb_width * mb_y + mb_x] = varc;
    s->avg_mb_var+= varc;
    s->mc_mb_var += vard;

    
#if 0
    printf("varc=%4d avg_var=%4d (sum=%4d) vard=%4d mx=%2d my=%2d\n",
	   varc, s->avg_mb_var, sum, vard, mx - xx, my - yy);
#endif
    if(s->flags&CODEC_FLAG_HQ){
        if (vard*2 + 200 > varc)
            mb_type|= MB_TYPE_INTRA;
        if (varc*2 + 200 > vard){
            mb_type|= MB_TYPE_INTER;
            halfpel_motion_search(s, &mx, &my, dmin, xmin, ymin, xmax, ymax, pred_x, pred_y, ref_picture);
        }else{
            mx = mx*2 - mb_x*32;
            my = my*2 - mb_y*32;
        }
    }else{
        if (vard <= 64 || vard < varc) {
            mb_type|= MB_TYPE_INTER;
            if (s->me_method != ME_ZERO) {
                halfpel_motion_search(s, &mx, &my, dmin, xmin, ymin, xmax, ymax, pred_x, pred_y, ref_picture);
            } else {
                mx -= 16 * mb_x;
                my -= 16 * mb_y;
            }
#if 0
            if (vard < 10) {
                skip++;
                fprintf(stderr,"\nEarly skip: %d vard: %2d varc: %5d dmin: %d", 
                                skip, vard, varc, dmin);
            }
#endif
        }else{
            mb_type|= MB_TYPE_INTRA;
            mx = 0;//mx*2 - 32 * mb_x;
            my = 0;//my*2 - 32 * mb_y;
        }
    }

    s->mb_type[mb_y*s->mb_width + mb_x]= mb_type;
    set_p_mv_tables(s, mx, my);
}

int ff_estimate_motion_b(MpegEncContext * s,
                       int mb_x, int mb_y, int16_t (*mv_table)[2], uint8_t *ref_picture, int f_code)
{
    int mx, my, range, dmin;
    int xmin, ymin, xmax, ymax;
    int rel_xmin, rel_ymin, rel_xmax, rel_ymax;
    int pred_x=0, pred_y=0;
    int P[6][2];
    const int shift= 1+s->quarter_sample;
    const int mot_stride = s->mb_width + 2;
    const int mot_xy = (mb_y + 1)*mot_stride + mb_x + 1;
    
    get_limits(s, &range, &xmin, &ymin, &xmax, &ymax, f_code);

    switch(s->me_method) {
    case ME_ZERO:
    default:
	no_motion_search(s, &mx, &my);
        dmin = 0;
        break;
    case ME_FULL:
	dmin = full_motion_search(s, &mx, &my, range, xmin, ymin, xmax, ymax, ref_picture);
        break;
    case ME_LOG:
	dmin = log_motion_search(s, &mx, &my, range / 2, xmin, ymin, xmax, ymax, ref_picture);
        break;
    case ME_PHODS:
	dmin = phods_motion_search(s, &mx, &my, range / 2, xmin, ymin, xmax, ymax, ref_picture);
        break;
    case ME_X1:
    case ME_EPZS:
       {

            rel_xmin= xmin - mb_x*16;
            rel_xmax= xmax - mb_x*16;
            rel_ymin= ymin - mb_y*16;
            rel_ymax= ymax - mb_y*16;

            P[0][0] = mv_table[mot_xy    ][0];
            P[0][1] = mv_table[mot_xy    ][1];
            P[1][0] = mv_table[mot_xy - 1][0];
            P[1][1] = mv_table[mot_xy - 1][1];
            if(P[1][0] > (rel_xmax<<shift)) P[1][0]= (rel_xmax<<shift);

            /* special case for first line */
            if ((mb_y == 0 || s->first_slice_line || s->first_gob_line)) {
                P[4][0] = P[1][0];
                P[4][1] = P[1][1];
            } else {
                P[2][0] = mv_table[mot_xy - mot_stride             ][0];
                P[2][1] = mv_table[mot_xy - mot_stride             ][1];
                P[3][0] = mv_table[mot_xy - mot_stride + 1         ][0];
                P[3][1] = mv_table[mot_xy - mot_stride + 1         ][1];
                if(P[2][1] > (rel_ymax<<shift)) P[2][1]= (rel_ymax<<shift);
                if(P[3][0] < (rel_xmin<<shift)) P[3][0]= (rel_xmin<<shift);
                if(P[3][1] > (rel_ymax<<shift)) P[3][1]= (rel_ymax<<shift);
        
                P[4][0]= mid_pred(P[1][0], P[2][0], P[3][0]);
                P[4][1]= mid_pred(P[1][1], P[2][1], P[3][1]);
            }
            pred_x= P[1][0];
            pred_y= P[1][1];
        }
        dmin = epzs_motion_search(s, &mx, &my, P, pred_x, pred_y, rel_xmin, rel_ymin, rel_xmax, rel_ymax, ref_picture);
 
        mx+= mb_x*16;
        my+= mb_y*16;
        break;
    }
    
    /* intra / predictive decision */
//    xx = mb_x * 16;
//    yy = mb_y * 16;

//    pix = s->new_picture[0] + (yy * s->linesize) + xx;
    /* At this point (mx,my) are full-pell and the absolute displacement */
//    ppix = ref_picture + (my * s->linesize) + mx;
    
    dmin= halfpel_motion_search(s, &mx, &my, dmin, xmin, ymin, xmax, ymax, pred_x, pred_y, ref_picture);

//    s->mb_type[mb_y*s->mb_width + mb_x]= mb_type;
    mv_table[mot_xy][0]= mx;
    mv_table[mot_xy][1]= my;
    return dmin;
}


static inline int check_bidir_mv(MpegEncContext * s,
                   int mb_x, int mb_y,
                   int motion_fx, int motion_fy,
                   int motion_bx, int motion_by,
                   int pred_fx, int pred_fy,
                   int pred_bx, int pred_by)
{
    //FIXME optimize?
    UINT16 *mv_penalty= s->mv_penalty[s->f_code] + MAX_MV; // f_code of the prev frame
    uint8_t *dest_y = s->me_scratchpad;
    uint8_t *ptr;
    int dxy;
    int src_x, src_y;
    int fbmin;

    fbmin = (mv_penalty[motion_fx-pred_fx] + mv_penalty[motion_fy-pred_fy])*s->qscale;

    dxy = ((motion_fy & 1) << 1) | (motion_fx & 1);
    src_x = mb_x * 16 + (motion_fx >> 1);
    src_y = mb_y * 16 + (motion_fy >> 1);
            
    ptr = s->last_picture[0] + (src_y * s->linesize) + src_x;
    put_pixels_tab[dxy](dest_y    , ptr    , s->linesize, 16);
    put_pixels_tab[dxy](dest_y + 8, ptr + 8, s->linesize, 16);
    
    fbmin += (mv_penalty[motion_bx-pred_bx] + mv_penalty[motion_by-pred_by])*s->qscale;

    dxy = ((motion_by & 1) << 1) | (motion_bx & 1);
    src_x = mb_x * 16 + (motion_bx >> 1);
    src_y = mb_y * 16 + (motion_by >> 1);
            
    ptr = s->next_picture[0] + (src_y * s->linesize) + src_x;
    avg_pixels_tab[dxy](dest_y    , ptr    , s->linesize, 16);
    avg_pixels_tab[dxy](dest_y + 8, ptr + 8, s->linesize, 16);
    
    fbmin += pix_abs16x16(s->new_picture[0] + mb_x*16 + mb_y*16*s->linesize, dest_y, s->linesize);
    return fbmin;
}

/* refine the bidir vectors in hq mode and return the score in both lq & hq mode*/
static inline int bidir_refine(MpegEncContext * s,
                                  int mb_x, int mb_y)
{
    const int mot_stride = s->mb_width + 2;
    const int xy = (mb_y + 1)*mot_stride + mb_x + 1;
    int fbmin;
    int pred_fx= s->b_bidir_forw_mv_table[xy-1][0];
    int pred_fy= s->b_bidir_forw_mv_table[xy-1][1];
    int pred_bx= s->b_bidir_back_mv_table[xy-1][0];
    int pred_by= s->b_bidir_back_mv_table[xy-1][1];
    int motion_fx= s->b_bidir_forw_mv_table[xy][0]= s->b_forw_mv_table[xy][0];
    int motion_fy= s->b_bidir_forw_mv_table[xy][1]= s->b_forw_mv_table[xy][1];
    int motion_bx= s->b_bidir_back_mv_table[xy][0]= s->b_back_mv_table[xy][0];
    int motion_by= s->b_bidir_back_mv_table[xy][1]= s->b_back_mv_table[xy][1];

    //FIXME do refinement and add flag
    
    fbmin= check_bidir_mv(s, mb_x, mb_y, 
                          motion_fx, motion_fy,
                          motion_bx, motion_by,
                          pred_fx, pred_fy,
                          pred_bx, pred_by);

   return fbmin;
}

static inline int direct_search(MpegEncContext * s,
                                int mb_x, int mb_y)
{
    int P[6][2];
    const int mot_stride = s->mb_width + 2;
    const int mot_xy = (mb_y + 1)*mot_stride + mb_x + 1;
    int dmin, dmin2;
    int motion_fx, motion_fy, motion_bx, motion_by, motion_bx0, motion_by0;
    int motion_dx, motion_dy;
    const int motion_px= s->p_mv_table[mot_xy][0];
    const int motion_py= s->p_mv_table[mot_xy][1];
    const int time_pp= s->pp_time;
    const int time_bp= s->bp_time;
    const int time_pb= time_pp - time_bp;
    int bx, by;
    int mx, my, mx2, my2;
    uint8_t *ref_picture= s->me_scratchpad - (mb_x + 1 + (mb_y + 1)*s->linesize)*16;
    int16_t (*mv_table)[2]= s->b_direct_mv_table;
    uint16_t *mv_penalty= s->mv_penalty[s->f_code] + MAX_MV; // f_code of the prev frame

    /* thanks to iso-mpeg the rounding is different for the zero vector, so we need to handle that ... */
    motion_fx= (motion_px*time_pb)/time_pp;
    motion_fy= (motion_py*time_pb)/time_pp;
    motion_bx0= (-motion_px*time_bp)/time_pp;
    motion_by0= (-motion_py*time_bp)/time_pp;
    motion_dx= motion_dy=0;
    dmin2= check_bidir_mv(s, mb_x, mb_y, 
                          motion_fx, motion_fy,
                          motion_bx0, motion_by0,
                          motion_fx, motion_fy,
                          motion_bx0, motion_by0) - s->qscale;

    motion_bx= motion_fx - motion_px;
    motion_by= motion_fy - motion_py;
    for(by=-1; by<2; by++){
        for(bx=-1; bx<2; bx++){
            uint8_t *dest_y = s->me_scratchpad + (by+1)*s->linesize*16 + (bx+1)*16;
            uint8_t *ptr;
            int dxy;
            int src_x, src_y;
            const int width= s->width;
            const int height= s->height;

            dxy = ((motion_fy & 1) << 1) | (motion_fx & 1);
            src_x = (mb_x + bx) * 16 + (motion_fx >> 1);
            src_y = (mb_y + by) * 16 + (motion_fy >> 1);
            src_x = clip(src_x, -16, width);
            if (src_x == width) dxy &= ~1;
            src_y = clip(src_y, -16, height);
            if (src_y == height) dxy &= ~2;

            ptr = s->last_picture[0] + (src_y * s->linesize) + src_x;
            put_pixels_tab[dxy](dest_y    , ptr    , s->linesize, 16);
            put_pixels_tab[dxy](dest_y + 8, ptr + 8, s->linesize, 16);

            dxy = ((motion_by & 1) << 1) | (motion_bx & 1);
            src_x = (mb_x + bx) * 16 + (motion_bx >> 1);
            src_y = (mb_y + by) * 16 + (motion_by >> 1);
            src_x = clip(src_x, -16, width);
            if (src_x == width) dxy &= ~1;
            src_y = clip(src_y, -16, height);
            if (src_y == height) dxy &= ~2;

            avg_pixels_tab[dxy](dest_y    , ptr    , s->linesize, 16);
            avg_pixels_tab[dxy](dest_y + 8, ptr + 8, s->linesize, 16);
        }
    }

    P[0][0] = mv_table[mot_xy    ][0];
    P[0][1] = mv_table[mot_xy    ][1];
    P[1][0] = mv_table[mot_xy - 1][0];
    P[1][1] = mv_table[mot_xy - 1][1];

    /* special case for first line */
    if ((mb_y == 0 || s->first_slice_line || s->first_gob_line)) {
        P[4][0] = P[1][0];
        P[4][1] = P[1][1];
    } else {
        P[2][0] = mv_table[mot_xy - mot_stride             ][0];
        P[2][1] = mv_table[mot_xy - mot_stride             ][1];
        P[3][0] = mv_table[mot_xy - mot_stride + 1         ][0];
        P[3][1] = mv_table[mot_xy - mot_stride + 1         ][1];
    
        P[4][0]= mid_pred(P[1][0], P[2][0], P[3][0]);
        P[4][1]= mid_pred(P[1][1], P[2][1], P[3][1]);
    }
    dmin = epzs_motion_search(s, &mx, &my, P, 0, 0, -16, -16, 15, 15, ref_picture);
    if(mx==0 && my==0) dmin=99999999; // not representable, due to rounding stuff
    if(dmin2<dmin){ 
        dmin= dmin2;
        mx=0;
        my=0;
    }
#if 1
    mx2= mx= mx*2; 
    my2= my= my*2;
    for(by=-1; by<2; by++){
        if(my2+by < -32) continue;
        for(bx=-1; bx<2; bx++){
            if(bx==0 && by==0) continue;
            if(mx2+bx < -32) continue;
            dmin2= check_bidir_mv(s, mb_x, mb_y, 
                          mx2+bx+motion_fx, my2+by+motion_fy,
                          mx2+bx+motion_bx, my2+by+motion_by,
                          mx2+bx+motion_fx, my2+by+motion_fy,
                          motion_bx, motion_by) - s->qscale;
            
            if(dmin2<dmin){
                dmin=dmin2;
                mx= mx2 + bx;
                my= my2 + by;
            }
        }
    }
#else
    mx*=2; my*=2;
#endif
    if(mx==0 && my==0){
        motion_bx= motion_bx0;
        motion_by= motion_by0;
    }

    s->b_direct_mv_table[mot_xy][0]= mx;
    s->b_direct_mv_table[mot_xy][1]= my;
    s->b_direct_forw_mv_table[mot_xy][0]= motion_fx + mx;
    s->b_direct_forw_mv_table[mot_xy][1]= motion_fy + my;
    s->b_direct_back_mv_table[mot_xy][0]= motion_bx + mx;
    s->b_direct_back_mv_table[mot_xy][1]= motion_by + my;
    return dmin;
}

void ff_estimate_b_frame_motion(MpegEncContext * s,
                             int mb_x, int mb_y)
{
    const int mot_stride = s->mb_width + 2;
    const int xy = (mb_y + 1)*mot_stride + mb_x + 1;
    const int quant= s->qscale;
    int fmin, bmin, dmin, fbmin;
    int type=0;
    int motion_fx, motion_fy, motion_bx, motion_by;
    
    dmin= direct_search(s, mb_x, mb_y);

    fmin= ff_estimate_motion_b(s, mb_x, mb_y, s->b_forw_mv_table, s->last_picture[0], s->f_code);
    bmin= ff_estimate_motion_b(s, mb_x, mb_y, s->b_back_mv_table, s->next_picture[0], s->b_code) - quant;
//printf(" %d %d ", s->b_forw_mv_table[xy][0], s->b_forw_mv_table[xy][1]);

    fbmin= bidir_refine(s, mb_x, mb_y);

    if(s->flags&CODEC_FLAG_HQ){
        type= MB_TYPE_FORWARD | MB_TYPE_BACKWARD | MB_TYPE_BIDIR | MB_TYPE_DIRECT;
    }else{
        int score= dmin;
        type=MB_TYPE_DIRECT;
        
        if(fmin<score){
            score=fmin;
            type= MB_TYPE_FORWARD; 
        }
        if(bmin<score){
            score=bmin;
            type= MB_TYPE_BACKWARD; 
        }
        if(fbmin<score){
            score=fbmin;
            type= MB_TYPE_BIDIR;
        }
        s->mc_mb_var += score;
    }

    s->mb_type[mb_y*s->mb_width + mb_x]= type;
}

/* find best f_code for ME which do unlimited searches */
int ff_get_best_fcode(MpegEncContext * s, int16_t (*mv_table)[2], int type)
{
    int f_code;

    if(s->me_method>=ME_EPZS){
        int mv_num[8];
        int i, y;
        int loose=0;
        UINT8 * fcode_tab= s->fcode_tab;

        for(i=0; i<8; i++) mv_num[i]=0;

        for(y=0; y<s->mb_height; y++){
            int x;
            int xy= (y+1)* (s->mb_width+2) + 1;
            i= y*s->mb_width;
            for(x=0; x<s->mb_width; x++){
                if(s->mb_type[i] & type){
                    mv_num[ fcode_tab[mv_table[xy][0] + MAX_MV] ]++;
                    mv_num[ fcode_tab[mv_table[xy][1] + MAX_MV] ]++;
//printf("%d %d %d\n", s->mv_table[0][i], fcode_tab[s->mv_table[0][i] + MAX_MV], i);
                }
                i++;
                xy++;
            }
        }

        for(i=MAX_FCODE; i>1; i--){
            int threshold;
            loose+= mv_num[i];

            if(s->pict_type==B_TYPE) threshold= 0;
            else                     threshold= s->mb_num/20; //FIXME 
            if(loose > threshold) break;
        }
//    printf("fcode: %d type: %d\n", i, s->pict_type);
        return i;
/*        for(i=0; i<=MAX_FCODE; i++){
            printf("%d ", mv_num[i]);
        }
        printf("\n");*/
    }else{
        return 1;
    }
}

void ff_fix_long_p_mvs(MpegEncContext * s)
{
    const int f_code= s->f_code;
    int y;
    UINT8 * fcode_tab= s->fcode_tab;

    /* clip / convert to intra 16x16 type MVs */
    for(y=0; y<s->mb_height; y++){
        int x;
        int xy= (y+1)* (s->mb_width+2)+1;
        int i= y*s->mb_width;
        for(x=0; x<s->mb_width; x++){
            if(s->mb_type[i]&MB_TYPE_INTER){
                if(   fcode_tab[s->p_mv_table[xy][0] + MAX_MV] > f_code
                   || fcode_tab[s->p_mv_table[xy][0] + MAX_MV] == 0
                   || fcode_tab[s->p_mv_table[xy][1] + MAX_MV] > f_code
                   || fcode_tab[s->p_mv_table[xy][1] + MAX_MV] == 0 ){
                    s->mb_type[i] &= ~MB_TYPE_INTER;
                    s->mb_type[i] |= MB_TYPE_INTRA;
                    s->p_mv_table[xy][0] = 0;
                    s->p_mv_table[xy][1] = 0;
                }
            }
            xy++;
            i++;
        }
    }

    if(s->flags&CODEC_FLAG_4MV){
        const int wrap= 2+ s->mb_width*2;

        /* clip / convert to intra 8x8 type MVs */
        for(y=0; y<s->mb_height; y++){
            int xy= (y*2 + 1)*wrap + 1;
            int i= y*s->mb_width;
            int x;

            for(x=0; x<s->mb_width; x++){
                if(s->mb_type[i]&MB_TYPE_INTER4V){
                    int block;
                    for(block=0; block<4; block++){
                        int off= (block& 1) + (block>>1)*wrap;
                        int mx= s->motion_val[ xy + off ][0];
                        int my= s->motion_val[ xy + off ][1];

                        if(   fcode_tab[mx + MAX_MV] > f_code
                           || fcode_tab[mx + MAX_MV] == 0
                           || fcode_tab[my + MAX_MV] > f_code
                           || fcode_tab[my + MAX_MV] == 0 ){
                            s->mb_type[i] &= ~MB_TYPE_INTER4V;
                            s->mb_type[i] |= MB_TYPE_INTRA;
                        }
                    }
                    xy+=2;
                    i++;
                }
            }
        }
    }
}

void ff_fix_long_b_mvs(MpegEncContext * s, int16_t (*mv_table)[2], int f_code, int type)
{
    int y;
    UINT8 * fcode_tab= s->fcode_tab;

    /* clip / convert to intra 16x16 type MVs */
    for(y=0; y<s->mb_height; y++){
        int x;
        int xy= (y+1)* (s->mb_width+2)+1;
        int i= y*s->mb_width;
        for(x=0; x<s->mb_width; x++){
            if(s->mb_type[i]&type){
                if(   fcode_tab[mv_table[xy][0] + MAX_MV] > f_code
                   || fcode_tab[mv_table[xy][0] + MAX_MV] == 0
                   || fcode_tab[mv_table[xy][1] + MAX_MV] > f_code
                   || fcode_tab[mv_table[xy][1] + MAX_MV] == 0 ){
                    if(s->mb_type[i]&(~type)) s->mb_type[i] &= ~type;
                    else{
                        mv_table[xy][0] = 0;
                        mv_table[xy][1] = 0;
                        //this is certainly bad FIXME            
                    }
                }
            }
            xy++;
            i++;
        }
    }
}