predict.c

H.264编码器

}

/****************************************************************************
 * 4x4 prediction for intra luma block DC, H, V, P
 ****************************************************************************/
static void predict_4x4_dc_128( uint8_t *src, int i_stride )
{
    int x,y;
    for( y = 0; y < 4; y++ )
    {
        for( x = 0; x < 4; x++ )
        {
            src[x] = 128;
        }
        src += i_stride;
    }
}
static void predict_4x4_dc_left( uint8_t *src, int i_stride )
{
    int x,y;
    int dc = ( src[-1+0*i_stride] + src[-1+i_stride]+
               src[-1+2*i_stride] + src[-1+3*i_stride] + 2 ) >> 2;

    for( y = 0; y < 4; y++ )
    {
        for( x = 0; x < 4; x++ )
        {
            src[x] = dc;
        }
        src += i_stride;
    }
}
static void predict_4x4_dc_top( uint8_t *src, int i_stride )
{
    int x,y;
    int dc = ( src[0 - i_stride] + src[1 - i_stride] +
               src[2 - i_stride] + src[3 - i_stride] + 2 ) >> 2;

    for( y = 0; y < 4; y++ )
    {
        for( x = 0; x < 4; x++ )
        {
            src[x] = dc;
        }
        src += i_stride;
    }
}
static void predict_4x4_dc( uint8_t *src, int i_stride )
{
    int x,y;
    int dc = ( src[-1+0*i_stride] + src[-1+i_stride]+
               src[-1+2*i_stride] + src[-1+3*i_stride] +
               src[0 - i_stride]  + src[1 - i_stride] +
               src[2 - i_stride]  + src[3 - i_stride] + 4 ) >> 3;

    for( y = 0; y < 4; y++ )
    {
        for( x = 0; x < 4; x++ )
        {
            src[x] = dc;
        }
        src += i_stride;
    }
}
static void predict_4x4_h( uint8_t *src, int i_stride )
{
    int i,j;

    for( i = 0; i < 4; i++ )
    {
        uint8_t v;

        v = src[-1];

        for( j = 0; j < 4; j++ )
        {
            src[j] = v;
        }
        src += i_stride;
    }
}
static void predict_4x4_v( uint8_t *src, int i_stride )
{
    int i,j;

    for( i = 0; i < 4; i++ )
    {
        for( j = 0; j < 4; j++ )
        {
            src[i * i_stride +j] = src[j - i_stride];
        }
    }
}

#define PREDICT_4x4_LOAD_LEFT \
    const int l0 = src[-1+0*i_stride];   \
    const int l1 = src[-1+1*i_stride];   \
    const int l2 = src[-1+2*i_stride];   \
    const int l3 = src[-1+3*i_stride];

#define PREDICT_4x4_LOAD_TOP \
    const int t0 = src[0-1*i_stride];   \
    const int t1 = src[1-1*i_stride];   \
    const int t2 = src[2-1*i_stride];   \
    const int t3 = src[3-1*i_stride];

#define PREDICT_4x4_LOAD_TOP_RIGHT \
    const int t4 = src[4-1*i_stride];   \
    const int t5 = src[5-1*i_stride];   \
    const int t6 = src[6-1*i_stride];   \
    const int t7 = src[7-1*i_stride];


static void predict_4x4_ddl( uint8_t *src, int i_stride )
{
    PREDICT_4x4_LOAD_TOP
    PREDICT_4x4_LOAD_TOP_RIGHT

    src[0*i_stride+0] = ( t0 + 2*t1+ t2 + 2 ) >> 2;

    src[0*i_stride+1] =
    src[1*i_stride+0] = ( t1 + 2*t2+ t3 + 2 ) >> 2;

    src[0*i_stride+2] =
    src[1*i_stride+1] =
    src[2*i_stride+0] = ( t2 + 2*t3+ t4 + 2 ) >> 2;

    src[0*i_stride+3] =
    src[1*i_stride+2] =
    src[2*i_stride+1] =
    src[3*i_stride+0] = ( t3 + 2*t4+ t5 + 2 ) >> 2;

    src[1*i_stride+3] =
    src[2*i_stride+2] =
    src[3*i_stride+1] = ( t4 + 2*t5+ t6 + 2 ) >> 2;

    src[2*i_stride+3] =
    src[3*i_stride+2] = ( t5 + 2*t6+ t7 + 2 ) >> 2;

    src[3*i_stride+3] = ( t6 + 3 * t7 + 2 ) >> 2;
}
static void predict_4x4_ddr( uint8_t *src, int i_stride )
{
    const int lt = src[-1-i_stride];
    PREDICT_4x4_LOAD_LEFT
    PREDICT_4x4_LOAD_TOP

    src[0*i_stride+0] =
    src[1*i_stride+1] =
    src[2*i_stride+2] =
    src[3*i_stride+3] = ( t0 + 2*lt +l0 + 2 ) >> 2;

    src[0*i_stride+1] =
    src[1*i_stride+2] =
    src[2*i_stride+3] = ( lt + 2 * t0 + t1 + 2 ) >> 2;

    src[0*i_stride+2] =
    src[1*i_stride+3] = ( t0 + 2 * t1 + t2 + 2 ) >> 2;

    src[0*i_stride+3] = ( t1 + 2 * t2 + t3 + 2 ) >> 2;

    src[1*i_stride+0] =
    src[2*i_stride+1] =
    src[3*i_stride+2] = ( lt + 2 * l0 + l1 + 2 ) >> 2;

    src[2*i_stride+0] =
    src[3*i_stride+1] = ( l0 + 2 * l1 + l2 + 2 ) >> 2;

    src[3*i_stride+0] = ( l1 + 2 * l2 + l3 + 2 ) >> 2;
}

static void predict_4x4_vr( uint8_t *src, int i_stride )
{
    const int lt = src[-1-i_stride];
    PREDICT_4x4_LOAD_LEFT
    PREDICT_4x4_LOAD_TOP
    /* produce warning as l3 is unused */

    src[0*i_stride+0]=
    src[2*i_stride+1]= ( lt + t0 + 1 ) >> 1;

    src[0*i_stride+1]=
    src[2*i_stride+2]= ( t0 + t1 + 1 ) >> 1;

    src[0*i_stride+2]=
    src[2*i_stride+3]= ( t1 + t2 + 1 ) >> 1;

    src[0*i_stride+3]= ( t2 + t3 + 1 ) >> 1;

    src[1*i_stride+0]=
    src[3*i_stride+1]= ( l0 + 2 * lt + t0 + 2 ) >> 2;

    src[1*i_stride+1]=
    src[3*i_stride+2]= ( lt + 2 * t0 + t1 + 2 ) >> 2;

    src[1*i_stride+2]=
    src[3*i_stride+3]= ( t0 + 2 * t1 + t2 + 2) >> 2;

    src[1*i_stride+3]= ( t1 + 2 * t2 + t3 + 2 ) >> 2;
    src[2*i_stride+0]= ( lt + 2 * l0 + l1 + 2 ) >> 2;
    src[3*i_stride+0]= ( l0 + 2 * l1 + l2 + 2 ) >> 2;
}

static void predict_4x4_hd( uint8_t *src, int i_stride )
{
    const int lt= src[-1-1*i_stride];
    PREDICT_4x4_LOAD_LEFT
    PREDICT_4x4_LOAD_TOP
    /* produce warning as t3 is unused */

    src[0*i_stride+0]=
    src[1*i_stride+2]= ( lt + l0 + 1 ) >> 1;
    src[0*i_stride+1]=
    src[1*i_stride+3]= ( l0 + 2 * lt + t0 + 2 ) >> 2;
    src[0*i_stride+2]= ( lt + 2 * t0 + t1 + 2 ) >> 2;
    src[0*i_stride+3]= ( t0 + 2 * t1 + t2 + 2 ) >> 2;
    src[1*i_stride+0]=
    src[2*i_stride+2]= ( l0 + l1 + 1 ) >> 1;
    src[1*i_stride+1]=
    src[2*i_stride+3]= ( lt + 2 * l0 + l1 + 2 ) >> 2;
    src[2*i_stride+0]=
    src[3*i_stride+2]= ( l1 + l2+ 1 ) >> 1;
    src[2*i_stride+1]=
    src[3*i_stride+3]= ( l0 + 2 * l1 + l2 + 2 ) >> 2;
    src[3*i_stride+0]= ( l2 + l3 + 1 ) >> 1;
    src[3*i_stride+1]= ( l1 + 2 * l2 + l3 + 2 ) >> 2;
}

static void predict_4x4_vl( uint8_t *src, int i_stride )
{
    PREDICT_4x4_LOAD_TOP
    PREDICT_4x4_LOAD_TOP_RIGHT
    /* produce warning as t7 is unused */

    src[0*i_stride+0]= ( t0 + t1 + 1 ) >> 1;
    src[0*i_stride+1]=
    src[2*i_stride+0]= ( t1 + t2 + 1 ) >> 1;
    src[0*i_stride+2]=
    src[2*i_stride+1]= ( t2 + t3 + 1 ) >> 1;
    src[0*i_stride+3]=
    src[2*i_stride+2]= ( t3 + t4+ 1 ) >> 1;
    src[2*i_stride+3]= ( t4 + t5+ 1 ) >> 1;
    src[1*i_stride+0]= ( t0 + 2 * t1 + t2 + 2 ) >> 2;
    src[1*i_stride+1]=
    src[3*i_stride+0]= ( t1 + 2 * t2 + t3 + 2 ) >> 2;
    src[1*i_stride+2]=
    src[3*i_stride+1]= ( t2 + 2 * t3 + t4 + 2 ) >> 2;
    src[1*i_stride+3]=
    src[3*i_stride+2]= ( t3 + 2 * t4 + t5 + 2 ) >> 2;
    src[3*i_stride+3]= ( t4 + 2 * t5 + t6 + 2 ) >> 2;
}

static void predict_4x4_hu( uint8_t *src, int i_stride )
{
    PREDICT_4x4_LOAD_LEFT

    src[0*i_stride+0]= ( l0 + l1 + 1 ) >> 1;
    src[0*i_stride+1]= ( l0 + 2 * l1 + l2 + 2 ) >> 2;

    src[0*i_stride+2]=
    src[1*i_stride+0]= ( l1 + l2 + 1 ) >> 1;

    src[0*i_stride+3]=
    src[1*i_stride+1]= ( l1 + 2*l2 + l3 + 2 ) >> 2;

    src[1*i_stride+2]=
    src[2*i_stride+0]= ( l2 + l3 + 1 ) >> 1;

    src[1*i_stride+3]=
    src[2*i_stride+1]= ( l2 + 2 * l3 + l3 + 2 ) >> 2;

    src[2*i_stride+3]=
    src[3*i_stride+1]=
    src[3*i_stride+0]=
    src[2*i_stride+2]=
    src[3*i_stride+2]=
    src[3*i_stride+3]= l3;
}

/****************************************************************************
 * Exported functions:
 ****************************************************************************/
void x264_predict_16x16_init( x264_predict_t pf[7] )
{
    pf[I_PRED_16x16_V ]     = predict_16x16_v;
    pf[I_PRED_16x16_H ]     = predict_16x16_h;
    pf[I_PRED_16x16_DC]     = predict_16x16_dc;
    pf[I_PRED_16x16_P ]     = predict_16x16_p;
    pf[I_PRED_16x16_DC_LEFT]= predict_16x16_dc_left;
    pf[I_PRED_16x16_DC_TOP ]= predict_16x16_dc_top;
    pf[I_PRED_16x16_DC_128 ]= predict_16x16_dc_128;
}

void x264_predict_8x8_init(  x264_predict_t pf[7] )
{
    pf[I_PRED_CHROMA_V ]     = predict_8x8_v;
    pf[I_PRED_CHROMA_H ]     = predict_8x8_h;
    pf[I_PRED_CHROMA_DC]     = predict_8x8_dc;
    pf[I_PRED_CHROMA_P ]     = predict_8x8_p;
    pf[I_PRED_CHROMA_DC_LEFT]= predict_8x8_dc_left;
    pf[I_PRED_CHROMA_DC_TOP ]= predict_8x8_dc_top;
    pf[I_PRED_CHROMA_DC_128 ]= predict_8x8_dc_128;
}

void x264_predict_4x4_init( x264_predict_t pf[12] )
{
    pf[I_PRED_4x4_V]      = predict_4x4_v;
    pf[I_PRED_4x4_H]      = predict_4x4_h;
    pf[I_PRED_4x4_DC]     = predict_4x4_dc;
    pf[I_PRED_4x4_DDL]    = predict_4x4_ddl;
    pf[I_PRED_4x4_DDR]    = predict_4x4_ddr;
    pf[I_PRED_4x4_VR]     = predict_4x4_vr;
    pf[I_PRED_4x4_HD]     = predict_4x4_hd;
    pf[I_PRED_4x4_VL]     = predict_4x4_vl;
    pf[I_PRED_4x4_HU]     = predict_4x4_hu;
    pf[I_PRED_4x4_DC_LEFT]= predict_4x4_dc_left;
    pf[I_PRED_4x4_DC_TOP] = predict_4x4_dc_top;
    pf[I_PRED_4x4_DC_128] = predict_4x4_dc_128;
}