motion_est.c

ffmpeg的完整源代码和作者自己写的文档。不但有在Linux的工程哦

    pix = s->new_picture.data[0] + (yy * s->linesize) + xx;
    dmin = 0x7fffffff;
    mx = 0;
    my = 0;
    for (y = y1; y <= y2; y++) {
        for (x = x1; x <= x2; x++) {
            d = s->dsp.pix_abs[0][0](NULL, pix, ref_picture + (y * s->linesize) + x,
                             s->linesize, 16);
            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)) {
        av_log(NULL, AV_LOG_ERROR, "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_t *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.data[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 = s->dsp.pix_abs[0][0](NULL, pix, ref_picture + (y * s->linesize) + x, s->linesize, 16);
                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
    av_log(s->avctx, AV_LOG_DEBUG, "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_t *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.data[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 = s->dsp.pix_abs[0][0](NULL, pix, ref_picture + (y * s->linesize) + x, s->linesize, 16);
            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 = s->dsp.pix_abs[0][0](NULL, pix, ref_picture + (y * s->linesize) + x, s->linesize, 16);
            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
    av_log(s->avctx, AV_LOG_DEBUG, "phods     - MX: %d\tMY: %d\n", mx, my);
#endif

    /* half pixel search */
    *mx_ptr = mx;
    *my_ptr = my;
    return dminy;
}
#endif /* 0 */

#define Z_THRESHOLD 256

#define CHECK_SAD_HALF_MV(suffix, x, y) \
{\
    d= s->dsp.pix_abs[size][(x?1:0)+(y?2:0)](NULL, pix, ptr+((x)>>1), stride, h);\
    d += (mv_penalty[pen_x + x] + mv_penalty[pen_y + y])*penalty_factor;\
    COPY3_IF_LT(dminh, d, dx, x, dy, y)\
}

static inline int sad_hpel_motion_search(MpegEncContext * s,
                                  int *mx_ptr, int *my_ptr, int dmin,
                                  int src_index, int ref_index,
                                  int size, int h)
{
    MotionEstContext * const c= &s->me;
    const int penalty_factor= c->sub_penalty_factor;
    int mx, my, dminh;
    uint8_t *pix, *ptr;
    int stride= c->stride;
    const int flags= c->sub_flags;
    LOAD_COMMON

    assert(flags == 0);

    if(c->skip){
//    printf("S");
        *mx_ptr = 0;
        *my_ptr = 0;
        return dmin;
    }
//    printf("N");

    pix = c->src[src_index][0];

    mx = *mx_ptr;
    my = *my_ptr;
    ptr = c->ref[ref_index][0] + (my * stride) + mx;

    dminh = dmin;

    if (mx > xmin && mx < xmax &&
        my > ymin && my < ymax) {
        int dx=0, dy=0;
        int d, pen_x, pen_y;
        const int index= (my<<ME_MAP_SHIFT) + mx;
        const int t= score_map[(index-(1<<ME_MAP_SHIFT))&(ME_MAP_SIZE-1)];
        const int l= score_map[(index- 1               )&(ME_MAP_SIZE-1)];
        const int r= score_map[(index+ 1               )&(ME_MAP_SIZE-1)];
        const int b= score_map[(index+(1<<ME_MAP_SHIFT))&(ME_MAP_SIZE-1)];
        mx<<=1;
        my<<=1;


        pen_x= pred_x + mx;
        pen_y= pred_y + my;

        ptr-= stride;
        if(t<=b){
            CHECK_SAD_HALF_MV(y2 , 0, -1)
            if(l<=r){
                CHECK_SAD_HALF_MV(xy2, -1, -1)
                if(t+r<=b+l){
                    CHECK_SAD_HALF_MV(xy2, +1, -1)
                    ptr+= stride;
                }else{
                    ptr+= stride;
                    CHECK_SAD_HALF_MV(xy2, -1, +1)
                }
                CHECK_SAD_HALF_MV(x2 , -1,  0)
            }else{
                CHECK_SAD_HALF_MV(xy2, +1, -1)
                if(t+l<=b+r){
                    CHECK_SAD_HALF_MV(xy2, -1, -1)
                    ptr+= stride;
                }else{
                    ptr+= stride;
                    CHECK_SAD_HALF_MV(xy2, +1, +1)
                }
                CHECK_SAD_HALF_MV(x2 , +1,  0)
            }
        }else{
            if(l<=r){
                if(t+l<=b+r){
                    CHECK_SAD_HALF_MV(xy2, -1, -1)
                    ptr+= stride;
                }else{
                    ptr+= stride;
                    CHECK_SAD_HALF_MV(xy2, +1, +1)
                }
                CHECK_SAD_HALF_MV(x2 , -1,  0)
                CHECK_SAD_HALF_MV(xy2, -1, +1)
            }else{
                if(t+r<=b+l){
                    CHECK_SAD_HALF_MV(xy2, +1, -1)
                    ptr+= stride;
                }else{
                    ptr+= stride;
                    CHECK_SAD_HALF_MV(xy2, -1, +1)
                }
                CHECK_SAD_HALF_MV(x2 , +1,  0)
                CHECK_SAD_HALF_MV(xy2, +1, +1)
            }
            CHECK_SAD_HALF_MV(y2 ,  0, +1)
        }
        mx+=dx;
        my+=dy;

    }else{
        mx<<=1;
        my<<=1;
    }

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

static inline void set_p_mv_tables(MpegEncContext * s, int mx, int my, int mv4)
{
    const int xy= s->mb_x + s->mb_y*s->mb_stride;

    s->p_mv_table[xy][0] = mx;
    s->p_mv_table[xy][1] = my;

    /* has already been set to the 4 MV if 4MV is done */
    if(mv4){
        int mot_xy= s->block_index[0];

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

        mot_xy += s->b8_stride;
        s->current_picture.motion_val[0][mot_xy  ][0]= mx;
        s->current_picture.motion_val[0][mot_xy  ][1]= my;
        s->current_picture.motion_val[0][mot_xy+1][0]= mx;
        s->current_picture.motion_val[0][mot_xy+1][1]= my;
    }
}

/**
 * get fullpel ME search limits.
 */
static inline void get_limits(MpegEncContext *s, int x, int y)
{
    MotionEstContext * const c= &s->me;
    int range= c->avctx->me_range >> (1 + !!(c->flags&FLAG_QPEL));
/*
    if(c->avctx->me_range) c->range= c->avctx->me_range >> 1;
    else                   c->range= 16;
*/
    if (s->unrestricted_mv) {
        c->xmin = - x - 16;
        c->ymin = - y - 16;