mc.c

H.264编码器

/* mc.c: h264 encoder library (Motion Compensation) */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "stdint.h"

#include "x264.h"

#include "mc.h"
#include "clip1.h"

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;
    }
}

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];
        }
    }
}

/* mc I+H */
static void mc_xy10( uint8_t *src, int i_src_stride, uint8_t *dst, int i_dst_stride, int i_width, int i_height )
{
    uint8_t tmp[16*16];
    mc_hh( src, i_src_stride, tmp, i_width, i_width, i_height );
    pixel_avg( dst, i_dst_stride, src, i_src_stride, tmp, i_width, i_width, i_height );
}
static void mc_xy30( uint8_t *src, int i_src_stride, uint8_t *dst, int i_dst_stride, int i_width, int i_height )
{
    uint8_t tmp[16*16];
    mc_hh( src, i_src_stride, tmp, i_width, i_width, i_height );
    pixel_avg( dst, i_dst_stride, src+1, i_src_stride, tmp, i_width, i_width, i_height );
}
/* mc I+V */
static void mc_xy01( uint8_t *src, int i_src_stride, uint8_t *dst, int i_dst_stride, int i_width, int i_height )
{
    uint8_t tmp[16*16];
    mc_hv( src, i_src_stride, tmp, i_width, i_width, i_height );
    pixel_avg( dst, i_dst_stride, src, i_src_stride, tmp, i_width, i_width, i_height );
}
static void mc_xy03( uint8_t *src, int i_src_stride, uint8_t *dst, int i_dst_stride, int i_width, int i_height )
{
    uint8_t tmp[16*16];
    mc_hv( src, i_src_stride, tmp, i_width, i_width, i_height );
    pixel_avg( dst, i_dst_stride, src+i_src_stride, i_src_stride, tmp, i_width, i_width, i_height );
}
/* H+V */
static void mc_xy11( uint8_t *src, int i_src_stride, uint8_t *dst, int i_dst_stride, int i_width, int i_height )
{
    uint8_t tmp1[16*16];
    uint8_t tmp2[16*16];

    mc_hv( src, i_src_stride, tmp1, i_width, i_width, i_height );
    mc_hh( src, i_src_stride, tmp2, i_width, i_width, i_height );
    pixel_avg( dst, i_dst_stride, tmp1, i_width, tmp2, i_width, i_width, i_height );
}
static void mc_xy31( uint8_t *src, int i_src_stride, uint8_t *dst, int i_dst_stride, int i_width, int i_height )
{
    uint8_t tmp1[16*16];
    uint8_t tmp2[16*16];

    mc_hv( src+1, i_src_stride, tmp1, i_width, i_width, i_height );
    mc_hh( src,   i_src_stride, tmp2, i_width, i_width, i_height );
    pixel_avg( dst, i_dst_stride, tmp1, i_width, tmp2, i_width, i_width, i_height );
}
static void mc_xy13( uint8_t *src, int i_src_stride, uint8_t *dst, int i_dst_stride, int i_width, int i_height )
{
    uint8_t tmp1[16*16];
    uint8_t tmp2[16*16];

    mc_hv( src,              i_src_stride, tmp1, i_width, i_width, i_height );
    mc_hh( src+i_src_stride, i_src_stride, tmp2, i_width, i_width, i_height );
    pixel_avg( dst, i_dst_stride, tmp1, i_width, tmp2, i_width, i_width, i_height );
}
static void mc_xy33( uint8_t *src, int i_src_stride, uint8_t *dst, int i_dst_stride, int i_width, int i_height )
{
    uint8_t tmp1[16*16];
    uint8_t tmp2[16*16];

    mc_hv( src+1,            i_src_stride, tmp1, i_width, i_width, i_height );
    mc_hh( src+i_src_stride, i_src_stride, tmp2, i_width, i_width, i_height );
    pixel_avg( dst, i_dst_stride, tmp1, i_width, tmp2, i_width, i_width, i_height );
}
static void mc_xy21( uint8_t *src, int i_src_stride, uint8_t *dst, int i_dst_stride, int i_width, int i_height )
{
    uint8_t tmp1[16*16];
    uint8_t tmp2[16*16];

    mc_hc( src, i_src_stride, tmp1, i_width, i_width, i_height );
    mc_hh( src, i_src_stride, tmp2, i_width, i_width, i_height );
    pixel_avg( dst, i_dst_stride, tmp1, i_width, tmp2, i_width, i_width, i_height );
}
static void mc_xy12( uint8_t *src, int i_src_stride, uint8_t *dst, int i_dst_stride, int i_width, int i_height )
{
    uint8_t tmp1[16*16];
    uint8_t tmp2[16*16];

    mc_hc( src, i_src_stride, tmp1, i_width, i_width, i_height );
    mc_hv( src, i_src_stride, tmp2, i_width, i_width, i_height );
    pixel_avg( dst, i_dst_stride, tmp1, i_width, tmp2, i_width, i_width, i_height );
}
static void mc_xy32( uint8_t *src, int i_src_stride, uint8_t *dst, int i_dst_stride, int i_width, int i_height )
{
    uint8_t tmp1[16*16];
    uint8_t tmp2[16*16];

    mc_hc( src,   i_src_stride, tmp1, i_width, i_width, i_height );
    mc_hv( src+1, i_src_stride, tmp2, i_width, i_width, i_height );
    pixel_avg( dst, i_dst_stride, tmp1, i_width, tmp2, i_width, i_width, i_height );
}
static void mc_xy23( uint8_t *src, int i_src_stride, uint8_t *dst, int i_dst_stride, int i_width, int i_height )
{
    uint8_t tmp1[16*16];
    uint8_t tmp2[16*16];

    mc_hc( src,              i_src_stride, tmp1, i_width, i_width, i_height );
    mc_hh( src+i_src_stride, i_src_stride, tmp2, i_width, i_width, i_height );
    pixel_avg( dst, i_dst_stride, tmp1, i_width, tmp2, i_width, i_width, i_height );
}

static void motion_compensation_luma( uint8_t *src, int i_src_stride,
                                      uint8_t *dst, int i_dst_stride,
                                      int mvx,int mvy,
                                      int i_width, int i_height )
{
    static pf_mc_t pf_mc[4][4] =    /*XXX [dqy][dqx] */
    {
        { mc_copy,  mc_xy10,    mc_hh,      mc_xy30 },
        { mc_xy01,  mc_xy11,    mc_xy21,    mc_xy31 },
        { mc_hv,    mc_xy12,    mc_hc,      mc_xy32 },
        { mc_xy03,  mc_xy13,    mc_xy23,    mc_xy33 },
    };

    src += (mvy >> 2) * i_src_stride + (mvx >> 2);
    pf_mc[mvy&0x03][mvx&0x03]( src, i_src_stride, dst, i_dst_stride, i_width, i_height );
}

/* 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;
    }
}

void x264_mc_init(  x264_mc_t pf[2] )
{
    pf[MC_LUMA]   = motion_compensation_luma;
    pf[MC_CHROMA] = motion_compensation_chroma;

#ifdef HAVE_MMXEXT
    if( cpu&X264_CPU_MMXEXT )
    {
        x264_mc_mmxext_init( pf );
    }
#endif
#ifdef HAVE_ALTIVEC
    if( cpu&X264_CPU_ALTIVEC )
    {
        x264_mc_altivec_init( pf );
    }
#endif
}