me.c

X264的纯C语言的的原码

/*****************************************************************************
 * me.c: h264 encoder library (Motion Estimation)
 *****************************************************************************
 * Copyright (C) 2003 Laurent Aimar
 * $Id: me.c,v 1.1 2004/06/03 19:27:08 fenrir Exp $
 *
 * Authors: Laurent Aimar <[e-mail]>
 *          Loren Merritt <[e-mail]>
 *
 * 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., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
 *****************************************************************************/

#include <stdio.h>
#include <string.h>

#include "common.h"
#include "me.h"

/* presets selected from good points on the speed-vs-quality curve of several test videos
 * subpel_iters[i_subpel_refine] = { refine_hpel, refine_qpel, me_hpel, me_qpel }
 * where me_* are the number of EPZS iterations run on all candidate block types,
 * and refine_* are run only on the winner. */
static const int subpel_iterations[][4] = 
   {{1,0,0,0},
    {1,1,0,0},
    {0,1,1,0},
    {0,2,1,0},
    {0,2,1,1},
    {0,2,1,2},
    {0,0,2,2},
    {0,0,2,2}};

static void refine_subpel( x264_t *h, x264_me_t *m, int hpel_iters, int qpel_iters, int *p_halfpel_thresh, int b_refine_qpel );

#define BITS_MVD( mx, my )\
    (p_cost_mvx[(mx)<<2] + p_cost_mvy[(my)<<2])

#define COST_MV( mx, my )\
{\
    int cost = h->pixf.sad[i_pixel]( m->p_fenc[0], FENC_STRIDE,\
                   &p_fref[(my)*m->i_stride[0]+(mx)], m->i_stride[0] )\
             + BITS_MVD(mx,my);\
    COPY3_IF_LT( bcost, cost, bmx, mx, bmy, my );\
}

#define COST_MV_PRED( mx, my ) \
{ \
    int stride = 16; \
    uint8_t *src = h->mc.get_ref( m->p_fref, m->i_stride[0], pix, &stride, mx, my, bw, bh ); \
    int cost = h->pixf.sad[i_pixel]( m->p_fenc[0], FENC_STRIDE, src, stride ) \
             + p_cost_mvx[ mx ] + p_cost_mvy[ my ]; \
    COPY3_IF_LT( bpred_cost, cost, bpred_mx, mx, bpred_my, my ); \
}

#define COST_MV_X3_DIR( m0x, m0y, m1x, m1y, m2x, m2y, costs )\
{\
    uint8_t *pix_base = p_fref + bmx + bmy*m->i_stride[0];\
    h->pixf.sad_x3[i_pixel]( m->p_fenc[0],\
        pix_base + (m0x) + (m0y)*m->i_stride[0],\
        pix_base + (m1x) + (m1y)*m->i_stride[0],\
        pix_base + (m2x) + (m2y)*m->i_stride[0],\
        m->i_stride[0], costs );\
    (costs)[0] += BITS_MVD( bmx+(m0x), bmy+(m0y) );\
    (costs)[1] += BITS_MVD( bmx+(m1x), bmy+(m1y) );\
    (costs)[2] += BITS_MVD( bmx+(m2x), bmy+(m2y) );\
}

#define COST_MV_X4( m0x, m0y, m1x, m1y, m2x, m2y, m3x, m3y )\
{\
    uint8_t *pix_base = p_fref + omx + omy*m->i_stride[0];\
    h->pixf.sad_x4[i_pixel]( m->p_fenc[0],\
        pix_base + (m0x) + (m0y)*m->i_stride[0],\
        pix_base + (m1x) + (m1y)*m->i_stride[0],\
        pix_base + (m2x) + (m2y)*m->i_stride[0],\
        pix_base + (m3x) + (m3y)*m->i_stride[0],\
        m->i_stride[0], costs );\
    costs[0] += BITS_MVD( omx+(m0x), omy+(m0y) );\
    costs[1] += BITS_MVD( omx+(m1x), omy+(m1y) );\
    costs[2] += BITS_MVD( omx+(m2x), omy+(m2y) );\
    costs[3] += BITS_MVD( omx+(m3x), omy+(m3y) );\
    COPY3_IF_LT( bcost, costs[0], bmx, omx+(m0x), bmy, omy+(m0y) );\
    COPY3_IF_LT( bcost, costs[1], bmx, omx+(m1x), bmy, omy+(m1y) );\
    COPY3_IF_LT( bcost, costs[2], bmx, omx+(m2x), bmy, omy+(m2y) );\
    COPY3_IF_LT( bcost, costs[3], bmx, omx+(m3x), bmy, omy+(m3y) );\
}

#define COST_MV_X4_ABS( m0x, m0y, m1x, m1y, m2x, m2y, m3x, m3y )\
{\
    h->pixf.sad_x4[i_pixel]( m->p_fenc[0],\
        p_fref + (m0x) + (m0y)*m->i_stride[0],\
        p_fref + (m1x) + (m1y)*m->i_stride[0],\
        p_fref + (m2x) + (m2y)*m->i_stride[0],\
        p_fref + (m3x) + (m3y)*m->i_stride[0],\
        m->i_stride[0], costs );\
    costs[0] += BITS_MVD( m0x, m0y );\
    costs[1] += BITS_MVD( m1x, m1y );\
    costs[2] += BITS_MVD( m2x, m2y );\
    costs[3] += BITS_MVD( m3x, m3y );\
    COPY3_IF_LT( bcost, costs[0], bmx, m0x, bmy, m0y );\
    COPY3_IF_LT( bcost, costs[1], bmx, m1x, bmy, m1y );\
    COPY3_IF_LT( bcost, costs[2], bmx, m2x, bmy, m2y );\
    COPY3_IF_LT( bcost, costs[3], bmx, m3x, bmy, m3y );\
}

/*  1  */
/* 101 */
/*  1  */
#define DIA1_ITER( mx, my )\
{\
    omx = mx; omy = my;\
    COST_MV_X4( 0,-1, 0,1, -1,0, 1,0 );\
}

#define CROSS( start, x_max, y_max )\
{\
    i = start;\
    if( x_max <= X264_MIN(mv_x_max-omx, omx-mv_x_min) )\
        for( ; i < x_max-2; i+=4 )\
            COST_MV_X4( i,0, -i,0, i+2,0, -i-2,0 );\
    for( ; i < x_max; i+=2 )\
    {\
        if( omx+i <= mv_x_max )\
            COST_MV( omx+i, omy );\
        if( omx-i >= mv_x_min )\
            COST_MV( omx-i, omy );\
    }\
    i = start;\
    if( y_max <= X264_MIN(mv_y_max-omy, omy-mv_y_min) )\
        for( ; i < y_max-2; i+=4 )\
            COST_MV_X4( 0,i, 0,-i, 0,i+2, 0,-i-2 );\
    for( ; i < y_max; i+=2 )\
    {\
        if( omy+i <= mv_y_max )\
            COST_MV( omx, omy+i );\
        if( omy-i >= mv_y_min )\
            COST_MV( omx, omy-i );\
    }\
}

void x264_me_search_ref( x264_t *h, x264_me_t *m, int (*mvc)[2], int i_mvc, int *p_halfpel_thresh )
{
    const int bw = x264_pixel_size[m->i_pixel].w;
    const int bh = x264_pixel_size[m->i_pixel].h;
    const int i_pixel = m->i_pixel;
    int i_me_range = h->param.analyse.i_me_range;
    int bmx, bmy, bcost;
    int bpred_mx = 0, bpred_my = 0, bpred_cost = COST_MAX;
    int omx, omy, pmx, pmy;
    uint8_t *p_fref = m->p_fref[0];
    DECLARE_ALIGNED( uint8_t, pix[16*16], 16 );
    
    int i, j;
    int dir;
    int costs[6];

    int mv_x_min = h->mb.mv_min_fpel[0];
    int mv_y_min = h->mb.mv_min_fpel[1];
    int mv_x_max = h->mb.mv_max_fpel[0];
    int mv_y_max = h->mb.mv_max_fpel[1];

    const int16_t *p_cost_mvx = m->p_cost_mv - m->mvp[0];
    const int16_t *p_cost_mvy = m->p_cost_mv - m->mvp[1];

    if( h->mb.i_me_method == X264_ME_UMH )
    {
        /* clamp mvp to inside frame+padding, so that we don't have to check it each iteration */
        p_cost_mvx = m->p_cost_mv - x264_clip3( m->mvp[0], h->mb.mv_min_spel[0], h->mb.mv_max_spel[0] );
        p_cost_mvy = m->p_cost_mv - x264_clip3( m->mvp[1], h->mb.mv_min_spel[1], h->mb.mv_max_spel[1] );
    }

    bmx = x264_clip3( m->mvp[0], mv_x_min*4, mv_x_max*4 );
    bmy = x264_clip3( m->mvp[1], mv_y_min*4, mv_y_max*4 );
    pmx = ( bmx + 2 ) >> 2;
    pmy = ( bmy + 2 ) >> 2;
    bcost = COST_MAX;

    /* try extra predictors if provided */
    if( h->mb.i_subpel_refine >= 3 )
    {
        COST_MV_PRED( bmx, bmy );
        for( i = 0; i < i_mvc; i++ )
        {
             const int mx = x264_clip3( mvc[i][0], mv_x_min*4, mv_x_max*4 );
             const int my = x264_clip3( mvc[i][1], mv_y_min*4, mv_y_max*4 );
             if( mx != bpred_mx || my != bpred_my )
                 COST_MV_PRED( mx, my );
        }
        bmx = ( bpred_mx + 2 ) >> 2;
        bmy = ( bpred_my + 2 ) >> 2;
        COST_MV( bmx, bmy );
    }
    else
    {
        /* check the MVP */
        COST_MV( pmx, pmy );
        /* I don't know why this helps */
        bcost -= BITS_MVD(bmx,bmy);
        
        for( i = 0; i < i_mvc; i++ )
        {
             const int mx = x264_clip3( ( mvc[i][0] + 2 ) >> 2, mv_x_min, mv_x_max );
             const int my = x264_clip3( ( mvc[i][1] + 2 ) >> 2, mv_y_min, mv_y_max );
             if( mx != bmx || my != bmy )
                 COST_MV( mx, my );
        }
    }
    
    COST_MV( 0, 0 );

    mv_x_max += 8;
    mv_y_max += 8;
    mv_x_min -= 8;
    mv_y_min -= 8;

    switch( h->mb.i_me_method )
    {
    case X264_ME_DIA:
        /* diamond search, radius 1 */
        for( i = 0; i < i_me_range; i++ )
        {
            DIA1_ITER( bmx, bmy );
            if( bmx == omx && bmy == omy )
                break;
        }
        break;

    case X264_ME_HEX:
me_hex2:
        /* hexagon search, radius 2 */
#if 0
        for( i = 0; i < i_me_range/2; i++ )
        {
            omx = bmx; omy = bmy;
            COST_MV( omx-2, omy   );
            COST_MV( omx-1, omy+2 );
            COST_MV( omx+1, omy+2 );
            COST_MV( omx+2, omy   );
            COST_MV( omx+1, omy-2 );
            COST_MV( omx-1, omy-2 );
            if( bmx == omx && bmy == omy )
                break;
        }
#else
        /* equivalent to the above, but eliminates duplicate candidates */
        dir = -2;

        /* hexagon */
        COST_MV_X3_DIR( -2,0, -1, 2,  1, 2, costs   );
        COST_MV_X3_DIR(  2,0,  1,-2, -1,-2, costs+3 );
        COPY2_IF_LT( bcost, costs[0], dir, 0 );
        COPY2_IF_LT( bcost, costs[1], dir, 1 );
        COPY2_IF_LT( bcost, costs[2], dir, 2 );
        COPY2_IF_LT( bcost, costs[3], dir, 3 );
        COPY2_IF_LT( bcost, costs[4], dir, 4 );
        COPY2_IF_LT( bcost, costs[5], dir, 5 );

        if( dir != -2 )
        {
            static const int hex2[8][2] = {{-1,-2}, {-2,0}, {-1,2}, {1,2}, {2,0}, {1,-2}, {-1,-2}, {-2,0}};
            bmx += hex2[dir+1][0];
            bmy += hex2[dir+1][1];
            /* half hexagon, not overlapping the previous iteration */
            for( i = 1; i < i_me_range/2; i++ )
            {
                static const int mod6[8] = {5,0,1,2,3,4,5,0};
                const int odir = mod6[dir+1];
                COST_MV_X3_DIR( hex2[odir+0][0], hex2[odir+0][1],
                                hex2[odir+1][0], hex2[odir+1][1],
                                hex2[odir+2][0], hex2[odir+2][1],
                                costs );
                dir = -2;
                COPY2_IF_LT( bcost, costs[0], dir, odir-1 );
                COPY2_IF_LT( bcost, costs[1], dir, odir   );
                COPY2_IF_LT( bcost, costs[2], dir, odir+1 );
                if( dir == -2 )
                    break;
                bmx += hex2[dir+1][0];
                bmy += hex2[dir+1][1];
            }
        }
#endif
        /* square refine */
        omx = bmx; omy = bmy;
        COST_MV_X4(  0,-1,  0,1, -1,0, 1,0 );
        COST_MV_X4( -1,-1, -1,1, 1,-1, 1,1 );
        break;

    case X264_ME_UMH:
        {
            /* Uneven-cross Multi-Hexagon-grid Search
             * as in JM, except with different early termination */