mc.c 16 KB
Newer Older
Laurent Aimar's avatar
Laurent Aimar committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
/*****************************************************************************
 * mc.c: h264 encoder library (Motion Compensation)
 *****************************************************************************
 * Copyright (C) 2003 Laurent Aimar
 * $Id: mc.c,v 1.1 2004/06/03 19:27:07 fenrir Exp $
 *
 * Authors: Laurent Aimar <fenrir@via.ecp.fr>
 *
 * 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.
 *****************************************************************************/

Loren Merritt's avatar
Loren Merritt committed
24
#include "common.h"
Laurent Aimar's avatar
Laurent Aimar committed
25 26
#include "clip1.h"

27
#ifdef HAVE_MMX
28
#include "i386/mc.h"
Laurent Aimar's avatar
Laurent Aimar committed
29
#endif
30
#ifdef ARCH_PPC
31
#include "ppc/mc.h"
Laurent Aimar's avatar
Laurent Aimar committed
32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61
#endif


static inline int x264_tapfilter( uint8_t *pix, int i_pix_next )
{
    return pix[-2*i_pix_next] - 5*pix[-1*i_pix_next] + 20*(pix[0] + pix[1*i_pix_next]) - 5*pix[ 2*i_pix_next] + pix[ 3*i_pix_next];
}
static inline int x264_tapfilter1( uint8_t *pix )
{
    return pix[-2] - 5*pix[-1] + 20*(pix[0] + pix[1]) - 5*pix[ 2] + pix[ 3];
}

static inline void pixel_avg( uint8_t *dst,  int i_dst_stride,
                              uint8_t *src1, int i_src1_stride,
                              uint8_t *src2, int i_src2_stride,
                              int i_width, int i_height )
{
    int x, y;
    for( y = 0; y < i_height; y++ )
    {
        for( x = 0; x < i_width; x++ )
        {
            dst[x] = ( src1[x] + src2[x] + 1 ) >> 1;
        }
        dst  += i_dst_stride;
        src1 += i_src1_stride;
        src2 += i_src2_stride;
    }
}

62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143
static inline void pixel_avg_wxh( uint8_t *dst, int i_dst, uint8_t *src, int i_src, int width, int height )
{
    int x, y;
    for( y = 0; y < height; y++ )
    {
        for( x = 0; x < width; x++ )
        {
            dst[x] = ( dst[x] + src[x] + 1 ) >> 1;
        }
        dst += i_dst;
        src += i_src;
    }
}

#define PIXEL_AVG_C( name, width, height ) \
static void name( uint8_t *pix1, int i_stride_pix1, \
                  uint8_t *pix2, int i_stride_pix2 ) \
{ \
    pixel_avg_wxh( pix1, i_stride_pix1, pix2, i_stride_pix2, width, height ); \
}
PIXEL_AVG_C( pixel_avg_16x16, 16, 16 )
PIXEL_AVG_C( pixel_avg_16x8,  16, 8 )
PIXEL_AVG_C( pixel_avg_8x16,  8, 16 )
PIXEL_AVG_C( pixel_avg_8x8,   8, 8 )
PIXEL_AVG_C( pixel_avg_8x4,   8, 4 )
PIXEL_AVG_C( pixel_avg_4x8,   4, 8 )
PIXEL_AVG_C( pixel_avg_4x4,   4, 4 )
PIXEL_AVG_C( pixel_avg_4x2,   4, 2 )
PIXEL_AVG_C( pixel_avg_2x4,   2, 4 )
PIXEL_AVG_C( pixel_avg_2x2,   2, 2 )


/* Implicit weighted bipred only:
 * assumes log2_denom = 5, offset = 0, weight1 + weight2 = 64 */
#define op_scale2(x) dst[x] = x264_clip_uint8( (dst[x]*i_weight1 + src[x]*i_weight2 + (1<<5)) >> 6 )
static inline void pixel_avg_weight_wxh( uint8_t *dst, int i_dst, uint8_t *src, int i_src, int width, int height, int i_weight1 ){
    int y;
    const int i_weight2 = 64 - i_weight1;
    for(y=0; y<height; y++, dst += i_dst, src += i_src){
        op_scale2(0);
        op_scale2(1);
        if(width==2) continue;
        op_scale2(2);
        op_scale2(3);
        if(width==4) continue;
        op_scale2(4);
        op_scale2(5);
        op_scale2(6);
        op_scale2(7);
        if(width==8) continue;
        op_scale2(8);
        op_scale2(9);
        op_scale2(10);
        op_scale2(11);
        op_scale2(12);
        op_scale2(13);
        op_scale2(14);
        op_scale2(15);
    }
}

#define PIXEL_AVG_WEIGHT_C( width, height ) \
static void pixel_avg_weight_##width##x##height( \
                uint8_t *pix1, int i_stride_pix1, \
                uint8_t *pix2, int i_stride_pix2, int i_weight1 ) \
{ \
    pixel_avg_weight_wxh( pix1, i_stride_pix1, pix2, i_stride_pix2, width, height, i_weight1 ); \
}

PIXEL_AVG_WEIGHT_C(16,16)
PIXEL_AVG_WEIGHT_C(16,8)
PIXEL_AVG_WEIGHT_C(8,16)
PIXEL_AVG_WEIGHT_C(8,8)
PIXEL_AVG_WEIGHT_C(8,4)
PIXEL_AVG_WEIGHT_C(4,8)
PIXEL_AVG_WEIGHT_C(4,4)
PIXEL_AVG_WEIGHT_C(4,2)
PIXEL_AVG_WEIGHT_C(2,4)
PIXEL_AVG_WEIGHT_C(2,2)
#undef op_scale2
#undef PIXEL_AVG_WEIGHT_C

Laurent Aimar's avatar
Laurent Aimar committed
144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222
typedef void (*pf_mc_t)(uint8_t *src, int i_src_stride, uint8_t *dst, int i_dst_stride, int i_width, int i_height );

static void mc_copy( uint8_t *src, int i_src_stride, uint8_t *dst, int i_dst_stride, int i_width, int i_height )
{
    int y;

    for( y = 0; y < i_height; y++ )
    {
        memcpy( dst, src, i_width );

        src += i_src_stride;
        dst += i_dst_stride;
    }
}
static inline void mc_hh( uint8_t *src, int i_src_stride, uint8_t *dst, int i_dst_stride, int i_width, int i_height )
{
    int x, y;

    for( y = 0; y < i_height; y++ )
    {
        for( x = 0; x < i_width; x++ )
        {
            dst[x] = x264_mc_clip1( ( x264_tapfilter1( &src[x] ) + 16 ) >> 5 );
        }
        src += i_src_stride;
        dst += i_dst_stride;
    }
}
static inline void mc_hv( uint8_t *src, int i_src_stride, uint8_t *dst, int i_dst_stride, int i_width, int i_height )
{
    int x, y;

    for( y = 0; y < i_height; y++ )
    {
        for( x = 0; x < i_width; x++ )
        {
            dst[x] = x264_mc_clip1( ( x264_tapfilter( &src[x], i_src_stride ) + 16 ) >> 5 );
        }
        src += i_src_stride;
        dst += i_dst_stride;
    }
}
static inline void mc_hc( uint8_t *src, int i_src_stride, uint8_t *dst, int i_dst_stride, int i_width, int i_height )
{
    uint8_t *out;
    uint8_t *pix;
    int x, y;

    for( x = 0; x < i_width; x++ )
    {
        int tap[6];

        pix = &src[x];
        out = &dst[x];

        tap[0] = x264_tapfilter1( &pix[-2*i_src_stride] );
        tap[1] = x264_tapfilter1( &pix[-1*i_src_stride] );
        tap[2] = x264_tapfilter1( &pix[ 0*i_src_stride] );
        tap[3] = x264_tapfilter1( &pix[ 1*i_src_stride] );
        tap[4] = x264_tapfilter1( &pix[ 2*i_src_stride] );

        for( y = 0; y < i_height; y++ )
        {
            tap[5] = x264_tapfilter1( &pix[ 3*i_src_stride] );

            *out = x264_mc_clip1( ( tap[0] - 5*tap[1] + 20 * tap[2] + 20 * tap[3] -5*tap[4] + tap[5] + 512 ) >> 10 );

            /* Next line */
            pix += i_src_stride;
            out += i_dst_stride;
            tap[0] = tap[1];
            tap[1] = tap[2];
            tap[2] = tap[3];
            tap[3] = tap[4];
            tap[4] = tap[5];
        }
    }
}

Loren Merritt's avatar
Loren Merritt committed
223 224 225
static const int hpel_ref0[16] = {0,1,1,1,0,1,1,1,2,3,3,3,0,1,1,1};
static const int hpel_ref1[16] = {0,0,0,0,2,2,3,2,2,2,3,2,2,2,3,2};

Loren Merritt's avatar
Loren Merritt committed
226 227
static void mc_luma( uint8_t *src[4], int i_src_stride,
                     uint8_t *dst,    int i_dst_stride,
Loren Merritt's avatar
Loren Merritt committed
228
                     int mvx, int mvy,
Loren Merritt's avatar
Loren Merritt committed
229
                     int i_width, int i_height )
230
{
Loren Merritt's avatar
Loren Merritt committed
231 232 233
    int qpel_idx = ((mvy&3)<<2) + (mvx&3);
    int offset = (mvy>>2)*i_src_stride + (mvx>>2);
    uint8_t *src1 = src[hpel_ref0[qpel_idx]] + offset + ((mvy&3) == 3) * i_src_stride;
234

Loren Merritt's avatar
Loren Merritt committed
235
    if( qpel_idx & 5 ) /* qpel interpolation needed */
236
    {
Loren Merritt's avatar
Loren Merritt committed
237
        uint8_t *src2 = src[hpel_ref1[qpel_idx]] + offset + ((mvx&3) == 3);
238 239 240 241 242 243 244 245 246
        pixel_avg( dst, i_dst_stride, src1, i_src_stride,
                   src2, i_src_stride, i_width, i_height );
    }
    else
    {
        mc_copy( src1, i_src_stride, dst, i_dst_stride, i_width, i_height );
    }
}

Loren Merritt's avatar
Loren Merritt committed
247
static uint8_t *get_ref( uint8_t *src[4], int i_src_stride,
Loren Merritt's avatar
Loren Merritt committed
248 249
                         uint8_t *dst,   int *i_dst_stride,
                         int mvx, int mvy,
Loren Merritt's avatar
Loren Merritt committed
250
                         int i_width, int i_height )
251
{
Loren Merritt's avatar
Loren Merritt committed
252 253 254
    int qpel_idx = ((mvy&3)<<2) + (mvx&3);
    int offset = (mvy>>2)*i_src_stride + (mvx>>2);
    uint8_t *src1 = src[hpel_ref0[qpel_idx]] + offset + ((mvy&3) == 3) * i_src_stride;
255

Loren Merritt's avatar
Loren Merritt committed
256
    if( qpel_idx & 5 ) /* qpel interpolation needed */
257
    {
Loren Merritt's avatar
Loren Merritt committed
258
        uint8_t *src2 = src[hpel_ref1[qpel_idx]] + offset + ((mvx&3) == 3);
259 260 261 262 263 264 265 266 267 268 269
        pixel_avg( dst, *i_dst_stride, src1, i_src_stride,
                   src2, i_src_stride, i_width, i_height );
        return dst;
    }
    else
    {
        *i_dst_stride = i_src_stride;
        return src1;
    }
}

Laurent Aimar's avatar
Laurent Aimar committed
270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303
/* full chroma mc (ie until 1/8 pixel)*/
static void motion_compensation_chroma( uint8_t *src, int i_src_stride,
                                        uint8_t *dst, int i_dst_stride,
                                        int mvx, int mvy,
                                        int i_width, int i_height )
{
    uint8_t *srcp;
    int x, y;

    const int d8x = mvx&0x07;
    const int d8y = mvy&0x07;

    const int cA = (8-d8x)*(8-d8y);
    const int cB = d8x    *(8-d8y);
    const int cC = (8-d8x)*d8y;
    const int cD = d8x    *d8y;

    src  += (mvy >> 3) * i_src_stride + (mvx >> 3);
    srcp = &src[i_src_stride];

    for( y = 0; y < i_height; y++ )
    {
        for( x = 0; x < i_width; x++ )
        {
            dst[x] = ( cA*src[x]  + cB*src[x+1] +
                       cC*srcp[x] + cD*srcp[x+1] + 32 ) >> 6;
        }
        dst  += i_dst_stride;

        src   = srcp;
        srcp += i_src_stride;
    }
}

Loren Merritt's avatar
Loren Merritt committed
304 305 306 307 308 309 310 311 312
#define MC_COPY(W) \
static void mc_copy_w##W( uint8_t *dst, int i_dst, uint8_t *src, int i_src, int i_height ) \
{ \
    mc_copy( src, i_src, dst, i_dst, W, i_height ); \
}
MC_COPY( 16 )
MC_COPY( 8 )
MC_COPY( 4 )

313 314 315 316 317 318 319 320 321 322 323
static void plane_copy( uint8_t *dst, int i_dst,
                        uint8_t *src, int i_src, int w, int h)
{
    while( h-- )
    {
        memcpy( dst, src, w );
        dst += i_dst;
        src += i_src;
    }
}

324 325 326 327 328 329 330
void prefetch_fenc_null( uint8_t *pix_y, int stride_y,
                         uint8_t *pix_uv, int stride_uv, int mb_x )
{}

void prefetch_ref_null( uint8_t *pix, int stride, int parity )
{}

331
void x264_mc_init( int cpu, x264_mc_functions_t *pf )
Laurent Aimar's avatar
Laurent Aimar committed
332
{
333 334 335
    pf->mc_luma   = mc_luma;
    pf->get_ref   = get_ref;
    pf->mc_chroma = motion_compensation_chroma;
Laurent Aimar's avatar
Laurent Aimar committed
336

337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358
    pf->avg[PIXEL_16x16]= pixel_avg_16x16;
    pf->avg[PIXEL_16x8] = pixel_avg_16x8;
    pf->avg[PIXEL_8x16] = pixel_avg_8x16;
    pf->avg[PIXEL_8x8]  = pixel_avg_8x8;
    pf->avg[PIXEL_8x4]  = pixel_avg_8x4;
    pf->avg[PIXEL_4x8]  = pixel_avg_4x8;
    pf->avg[PIXEL_4x4]  = pixel_avg_4x4;
    pf->avg[PIXEL_4x2]  = pixel_avg_4x2;
    pf->avg[PIXEL_2x4]  = pixel_avg_2x4;
    pf->avg[PIXEL_2x2]  = pixel_avg_2x2;
    
    pf->avg_weight[PIXEL_16x16]= pixel_avg_weight_16x16;
    pf->avg_weight[PIXEL_16x8] = pixel_avg_weight_16x8;
    pf->avg_weight[PIXEL_8x16] = pixel_avg_weight_8x16;
    pf->avg_weight[PIXEL_8x8]  = pixel_avg_weight_8x8;
    pf->avg_weight[PIXEL_8x4]  = pixel_avg_weight_8x4;
    pf->avg_weight[PIXEL_4x8]  = pixel_avg_weight_4x8;
    pf->avg_weight[PIXEL_4x4]  = pixel_avg_weight_4x4;
    pf->avg_weight[PIXEL_4x2]  = pixel_avg_weight_4x2;
    pf->avg_weight[PIXEL_2x4]  = pixel_avg_weight_2x4;
    pf->avg_weight[PIXEL_2x2]  = pixel_avg_weight_2x2;

Loren Merritt's avatar
Loren Merritt committed
359 360 361 362
    pf->copy[PIXEL_16x16] = mc_copy_w16;
    pf->copy[PIXEL_8x8]   = mc_copy_w8;
    pf->copy[PIXEL_4x4]   = mc_copy_w4;

363 364
    pf->plane_copy = plane_copy;

365 366 367
    pf->prefetch_fenc = prefetch_fenc_null;
    pf->prefetch_ref  = prefetch_ref_null;

368
#ifdef HAVE_MMX
Loren Merritt's avatar
Loren Merritt committed
369
    if( cpu&X264_CPU_MMXEXT ) {
Laurent Aimar's avatar
Laurent Aimar committed
370
        x264_mc_mmxext_init( pf );
Loren Merritt's avatar
Loren Merritt committed
371
        pf->mc_chroma = x264_mc_chroma_mmxext;
Loren Merritt's avatar
Loren Merritt committed
372
    }
373 374 375
    if( cpu&X264_CPU_SSE2 )
        x264_mc_sse2_init( pf );
#endif
376
#ifdef ARCH_PPC
Laurent Aimar's avatar
Laurent Aimar committed
377 378 379 380 381
    if( cpu&X264_CPU_ALTIVEC )
        x264_mc_altivec_init( pf );
#endif
}

382 383
extern void x264_hpel_filter_mmxext( uint8_t *dsth, uint8_t *dstv, uint8_t *dstc, uint8_t *src,
                                     int i_stride, int i_width, int i_height );
384

Loren Merritt's avatar
Loren Merritt committed
385
void x264_frame_filter( int cpu, x264_frame_t *frame, int b_interlaced, int mb_y, int b_end )
386 387
{
    const int x_inc = 16, y_inc = 16;
388
    const int stride = frame->i_stride[0] << b_interlaced;
Loren Merritt's avatar
Loren Merritt committed
389 390
    int start = (mb_y*16 >> b_interlaced) - 8;
    int height = ((b_end ? frame->i_lines[0] : mb_y*16) >> b_interlaced) + 8;
391 392
    int x, y;

Loren Merritt's avatar
Loren Merritt committed
393 394 395
    if( mb_y & b_interlaced )
        return;
    mb_y >>= b_interlaced;
396

397
#ifdef HAVE_MMX
398 399
    if ( cpu & X264_CPU_MMXEXT )
    {
Loren Merritt's avatar
Loren Merritt committed
400 401
        // buffer = 4 for deblock + 3 for 6tap, rounded to 8
        int offs = start*stride - 8;
402 403 404 405 406
        x264_hpel_filter_mmxext(
            frame->filtered[1] + offs,
            frame->filtered[2] + offs,
            frame->filtered[3] + offs,
            frame->plane[0] + offs,
Loren Merritt's avatar
Loren Merritt committed
407
            stride, stride - 48, height - start );
408 409 410
    }
    else
#endif
Loren Merritt's avatar
Loren Merritt committed
411
    {
Loren Merritt's avatar
Loren Merritt committed
412
        for( y = start; y < height; y += y_inc )
413
        {
414 415 416
            uint8_t *p_in = frame->plane[0] + y * stride - 8;
            uint8_t *p_h  = frame->filtered[1] + y * stride - 8;
            uint8_t *p_v  = frame->filtered[2] + y * stride - 8;
Loren Merritt's avatar
Loren Merritt committed
417
            uint8_t *p_c  = frame->filtered[3] + y * stride - 8;
418 419
            for( x = -8; x < stride - 64 + 8; x += x_inc )
            {
Loren Merritt's avatar
Loren Merritt committed
420 421 422
                mc_hh( p_in, stride, p_h, stride, x_inc, y_inc );
                mc_hv( p_in, stride, p_v, stride, x_inc, y_inc );
                mc_hc( p_in, stride, p_c, stride, x_inc, y_inc );
423 424 425

                p_h += x_inc;
                p_v += x_inc;
Loren Merritt's avatar
Loren Merritt committed
426
                p_c += x_inc;
427 428
                p_in += x_inc;
            }
429 430
        }
    }
431 432

    /* generate integral image:
Loren Merritt's avatar
Loren Merritt committed
433 434
     * frame->integral contains 2 planes. in the upper plane, each element is
     * the sum of an 8x8 pixel region with top-left corner on that point.
Loren Merritt's avatar
Loren Merritt committed
435
     * in the lower plane, 4x4 sums (needed only with --partitions p4x4). */
436

Loren Merritt's avatar
Loren Merritt committed
437
    if( frame->integral )
438
    {
Loren Merritt's avatar
Loren Merritt committed
439 440 441 442 443 444 445 446
        if( start < 0 )
        {
            memset( frame->integral - 32 * stride - 32, 0, stride * sizeof(uint16_t) );
            start = -32;
        }
        if( b_end )
            height += 24;
        for( y = start; y < height; y++ )
447 448
        {
            uint8_t  *ref  = frame->plane[0] + y * stride - 32;
Loren Merritt's avatar
Loren Merritt committed
449
            uint16_t *line = frame->integral + (y+1) * stride - 31;
450
            uint16_t v = line[0] = 0;
Loren Merritt's avatar
Loren Merritt committed
451
            for( x = 0; x < stride-1; x++ )
452
                line[x] = v += ref[x] + line[x-stride] - line[x-stride-1];
Loren Merritt's avatar
Loren Merritt committed
453 454
            line -= 8*stride;
            if( y >= 8-31 )
Loren Merritt's avatar
Loren Merritt committed
455
            {
Loren Merritt's avatar
Loren Merritt committed
456 457 458 459 460 461
                uint16_t *sum4 = line + frame->i_stride[0] * (frame->i_lines[0] + 64);
                for( x = 1; x < stride-8; x++, line++, sum4++ )
                {
                    sum4[0] =  line[4+4*stride] - line[4] - line[4*stride] + line[0];
                    line[0] += line[8+8*stride] - line[8] - line[8*stride];
                }
Loren Merritt's avatar
Loren Merritt committed
462 463
            }
        }
464
    }
465
}
466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500

void x264_frame_init_lowres( int cpu, x264_frame_t *frame )
{
    // FIXME: tapfilter?
    const int i_stride = frame->i_stride[0];
    const int i_stride2 = frame->i_stride_lowres;
    const int i_width2 = i_stride2 - 64;
    int x, y, i;
    for( y = 0; y < frame->i_lines_lowres - 1; y++ )
    {
        uint8_t *src0 = &frame->plane[0][2*y*i_stride];
        uint8_t *src1 = src0+i_stride;
        uint8_t *src2 = src1+i_stride;
        uint8_t *dst0 = &frame->lowres[0][y*i_stride2];
        uint8_t *dsth = &frame->lowres[1][y*i_stride2];
        uint8_t *dstv = &frame->lowres[2][y*i_stride2];
        uint8_t *dstc = &frame->lowres[3][y*i_stride2];
        for( x = 0; x < i_width2 - 1; x++ )
        {
            dst0[x] = (src0[2*x  ] + src0[2*x+1] + src1[2*x  ] + src1[2*x+1] + 2) >> 2;
            dsth[x] = (src0[2*x+1] + src0[2*x+2] + src1[2*x+1] + src1[2*x+2] + 2) >> 2;
            dstv[x] = (src1[2*x  ] + src1[2*x+1] + src2[2*x  ] + src2[2*x+1] + 2) >> 2;
            dstc[x] = (src1[2*x+1] + src1[2*x+2] + src2[2*x+1] + src2[2*x+2] + 2) >> 2;
        }
        dst0[x] = (src0[2*x  ] + src0[2*x+1] + src1[2*x  ] + src1[2*x+1] + 2) >> 2;
        dstv[x] = (src1[2*x  ] + src1[2*x+1] + src2[2*x  ] + src2[2*x+1] + 2) >> 2;
        dsth[x] = (src0[2*x+1] + src1[2*x+1] + 1) >> 1;
        dstc[x] = (src1[2*x+1] + src2[2*x+1] + 1) >> 1;
    }
    for( i = 0; i < 4; i++ )
        memcpy( &frame->lowres[i][y*i_stride2], &frame->lowres[i][(y-1)*i_stride2], i_width2 );

    for( y = 0; y < 16; y++ )
        for( x = 0; x < 16; x++ )
            frame->i_cost_est[x][y] = -1;
501 502

    x264_frame_expand_border_lowres( frame );
503 504
}