macroblock.c

H.264 source codes

        {
            /* copy dc coeff */
            dct2x2[block_idx_y[i]][block_idx_x[i]] = dct4x4[i][0][0];

            quant_4x4( dct4x4[i], i_qscale, b_inter ? 0 : 1 );
            scan_zigzag_4x4( h->dct.block[16+i+ch*4].residual_ac, dct4x4[i] );
            x264_mb_dequant_4x4( dct4x4[i], i_qscale );

            if( b_inter )
            {
                i_decimate_score += x264_mb_decimate_score( h->dct.block[16+i+ch*4].residual_ac, 15 );
            }
        }

        h->dctf.dct2x2dc( dct2x2 );
        quant_2x2_dc( dct2x2, i_qscale, b_inter ? 0 : 1 );
        scan_zigzag_2x2_dc( h->dct.chroma_dc[ch], dct2x2 );

        /* output samples to fdec */
        h->dctf.idct2x2dc( dct2x2 );
        x264_mb_dequant_2x2_dc( dct2x2, i_qscale );  /* XXX not inversed */

        if( b_inter && i_decimate_score < 7 )
        {
            /* Near null chroma 8x8 block so make it null (bits saving) */
            for( i = 0; i < 4; i++ )
            {
                int x, y;
                for( x = 0; x < 15; x++ )
                {
                    h->dct.block[16+i+ch*4].residual_ac[x] = 0;
                }
                for( x = 0; x < 4; x++ )
                {
                    for( y = 0; y < 4; y++ )
                    {
                        dct4x4[i][x][y] = 0;
                    }
                }
            }
        }

        /* calculate dct coeffs */
        for( i = 0; i < 4; i++ )
        {
            /* copy dc coeff */
            dct4x4[i][0][0] = dct2x2[block_idx_y[i]][block_idx_x[i]];
        }
        h->dctf.add8x8_idct( p_dst, i_stride, dct4x4 );
    }
}

static void x264_macroblock_encode_skip( x264_t *h )
{
    int i;
    h->mb.i_cbp_luma = 0x00;
    h->mb.i_cbp_chroma = 0x00;

    for( i = 0; i < 16+8; i++ )
    {
        h->mb.cache.non_zero_count[x264_scan8[i]] = 0;
    }

    /* store cbp */
    h->mb.cbp[h->mb.i_mb_xy] = 0;
}

/*****************************************************************************
 * x264_macroblock_encode_pskip:
 *  Encode an already marked skip block
 *****************************************************************************/
void x264_macroblock_encode_pskip( x264_t *h )
{
    const int mvx = x264_clip3( h->mb.cache.mv[0][x264_scan8[0]][0],
                                h->mb.mv_min[0], h->mb.mv_max[0] );
    const int mvy = x264_clip3( h->mb.cache.mv[0][x264_scan8[0]][1],
                                h->mb.mv_min[1], h->mb.mv_max[1] );

    /* Motion compensation XXX probably unneeded */
    h->mc.mc_luma( h->mb.pic.p_fref[0][0], h->mb.pic.i_stride[0],
                    h->mb.pic.p_fdec[0],       h->mb.pic.i_stride[0],
                    mvx, mvy, 16, 16 );

    /* Chroma MC */
    h->mc.mc_chroma( h->mb.pic.p_fref[0][0][4], h->mb.pic.i_stride[1],
                      h->mb.pic.p_fdec[1],       h->mb.pic.i_stride[1],
                      mvx, mvy, 8, 8 );

    h->mc.mc_chroma( h->mb.pic.p_fref[0][0][5], h->mb.pic.i_stride[2],
                      h->mb.pic.p_fdec[2],       h->mb.pic.i_stride[2],
                      mvx, mvy, 8, 8 );

    x264_macroblock_encode_skip( h );
}

/*****************************************************************************
 * x264_macroblock_encode:
 *****************************************************************************/
void x264_macroblock_encode( x264_t *h )
{
    int i_cbp_dc = 0;
    int i_qscale;
    int i;

    if( h->mb.i_type == P_SKIP )
    {
        /* A bit special */
        x264_macroblock_encode_pskip( h );
        return;
    }
    if( h->mb.i_type == B_SKIP )
    {
        /* XXX motion compensation is probably unneeded */
        x264_mb_mc( h );
        x264_macroblock_encode_skip( h );
        return;
    }

    /* quantification scale */
    i_qscale = h->mb.qp[h->mb.i_mb_xy];

    if( h->mb.i_type == I_16x16 )
    {
        const int i_mode = h->mb.i_intra16x16_pred_mode;
        /* do the right prediction */
        h->predict_16x16[i_mode]( h->mb.pic.p_fdec[0], h->mb.pic.i_stride[0] );

        /* encode the 16x16 macroblock */
        x264_mb_encode_i16x16( h, i_qscale );

        /* fix the pred mode value */
        h->mb.i_intra16x16_pred_mode = x264_mb_pred_mode16x16_fix[i_mode];
    }
    else if( h->mb.i_type == I_4x4 )
    {
        for( i = 0; i < 16; i++ )
        {
            const int i_dst = h->mb.pic.i_stride[0];
            uint8_t  *p_dst = &h->mb.pic.p_fdec[0][4 * block_idx_x[i] + 4 * block_idx_y[i] * i_dst];
            int      i_mode = h->mb.cache.intra4x4_pred_mode[x264_scan8[i]];

            /* Do the right prediction */
            h->predict_4x4[i_mode]( p_dst, i_dst );

            /* encode one 4x4 block */
            x264_mb_encode_i4x4( h, i, i_qscale );

            /* fix the pred mode value */
            h->mb.cache.intra4x4_pred_mode[x264_scan8[i]] = x264_mb_pred_mode4x4_fix[i_mode];
        }
    }
    else    /* Inter MB */
    {
        int16_t dct4x4[16][4][4];

        int i8x8, i4x4, idx;
        int i_decimate_mb = 0;

        /* Motion compensation */
        x264_mb_mc( h );

        h->dctf.sub16x16_dct( dct4x4,
                              h->mb.pic.p_fenc[0], h->mb.pic.i_stride[0],
                              h->mb.pic.p_fdec[0], h->mb.pic.i_stride[0] );

        for( i8x8 = 0; i8x8 < 4; i8x8++ )
        {
            int i_decimate_8x8;

            /* encode one 4x4 block */
            i_decimate_8x8 = 0;
            for( i4x4 = 0; i4x4 < 4; i4x4++ )
            {
                idx = i8x8 * 4 + i4x4;

                quant_4x4( dct4x4[idx], i_qscale, 0 );
                scan_zigzag_4x4full( h->dct.block[idx].luma4x4, dct4x4[idx] );
                x264_mb_dequant_4x4( dct4x4[idx], i_qscale );

                i_decimate_8x8 += x264_mb_decimate_score( h->dct.block[idx].luma4x4, 16 );
            }

            /* decimate this 8x8 block */
            i_decimate_mb += i_decimate_8x8;
            if( i_decimate_8x8 < 4 )
            {
                for( i4x4 = 0; i4x4 < 4; i4x4++ )
                {
                    int x, y;
                    idx = i8x8 * 4 + i4x4;
                    for( i = 0; i < 16; i++ )
                    {
                        h->dct.block[idx].luma4x4[i] = 0;
                    }
                    for( x = 0; x < 4; x++ )
                    {
                        for( y = 0; y < 4; y++ )
                        {
                            dct4x4[idx][x][y] = 0;
                        }
                    }
                }
            }
        }

        if( i_decimate_mb < 6 )
        {
            for( idx = 0; idx < 16; idx++ )
            {
                for( i = 0; i < 16; i++ )
                {
                    h->dct.block[idx].luma4x4[i] = 0;
                }
            }
        }
        else
        {
            h->dctf.add16x16_idct( h->mb.pic.p_fdec[0], h->mb.pic.i_stride[0], dct4x4 );
        }
    }

    /* encode chroma */
    i_qscale = i_chroma_qp_table[x264_clip3( i_qscale + h->pps->i_chroma_qp_index_offset, 0, 51 )];
    if( IS_INTRA( h->mb.i_type ) )
    {
        const int i_mode = h->mb.i_chroma_pred_mode;
        /* do the right prediction */
        h->predict_8x8[i_mode]( h->mb.pic.p_fdec[1], h->mb.pic.i_stride[1] );
        h->predict_8x8[i_mode]( h->mb.pic.p_fdec[2], h->mb.pic.i_stride[2] );

        /* fix the pred mode value */
        h->mb.i_chroma_pred_mode = x264_mb_pred_mode8x8_fix[i_mode];
    }

    /* encode the 8x8 blocks */
    x264_mb_encode_8x8( h, !IS_INTRA( h->mb.i_type ), i_qscale );

    /* Calculate the Luma/Chroma patern and non_zero_count */
    if( h->mb.i_type == I_16x16 )
    {
        h->mb.i_cbp_luma = 0x00;
        for( i = 0; i < 16; i++ )
        {
            const int nz = array_non_zero_count( h->dct.block[i].residual_ac, 15 );
            h->mb.cache.non_zero_count[x264_scan8[i]] = nz;
            if( nz > 0 )
            {
                h->mb.i_cbp_luma = 0x0f;
            }
        }
    }
    else
    {
        h->mb.i_cbp_luma = 0x00;
        for( i = 0; i < 16; i++ )
        {
            const int nz = array_non_zero_count( h->dct.block[i].luma4x4, 16 );
            h->mb.cache.non_zero_count[x264_scan8[i]] = nz;
            if( nz > 0 )
            {
                h->mb.i_cbp_luma |= 1 << (i/4);
            }
        }
    }

    /* Calculate the chroma patern */
    h->mb.i_cbp_chroma = 0x00;
    for( i = 0; i < 8; i++ )
    {
        const int nz = array_non_zero_count( h->dct.block[16+i].residual_ac, 15 );
        h->mb.cache.non_zero_count[x264_scan8[16+i]] = nz;
        if( nz > 0 )
        {
            h->mb.i_cbp_chroma = 0x02;    /* dc+ac (we can't do only ac) */
        }
    }
    if( h->mb.i_cbp_chroma == 0x00 &&
        ( array_non_zero_count( h->dct.chroma_dc[0], 4 ) > 0 || array_non_zero_count( h->dct.chroma_dc[1], 4 ) ) > 0 )
    {
        h->mb.i_cbp_chroma = 0x01;    /* dc only */
    }

    if( h->param.b_cabac )
    {
        if( h->mb.i_type == I_16x16 && array_non_zero_count( h->dct.luma16x16_dc, 16 ) > 0 )
            i_cbp_dc = 0x01;
        else
            i_cbp_dc = 0x00;

        if( array_non_zero_count( h->dct.chroma_dc[0], 4 ) > 0 )
            i_cbp_dc |= 0x02;
        if( array_non_zero_count( h->dct.chroma_dc[1], 4 ) > 0 )
            i_cbp_dc |= 0x04;
    }

    /* store cbp */
    h->mb.cbp[h->mb.i_mb_xy] = (i_cbp_dc << 8) | (h->mb.i_cbp_chroma << 4) | h->mb.i_cbp_luma;

    if( h->mb.i_type != I_16x16 && h->mb.i_cbp_luma == 0 && h->mb.i_cbp_chroma == 0 )
    {
        /* It won'y change anything at the decoder side but it is needed else the
         * decoder will fail to read the next QP */
        h->mb.qp[h->mb.i_mb_xy] = h->mb.i_last_qp;
    }


    /* Check for P_SKIP
     * XXX: in the me perhaps we should take x264_mb_predict_mv_pskip into account
     *      (if multiple mv give same result)*/
    if( h->mb.i_type == P_L0 && h->mb.i_partition == D_16x16 &&
        h->mb.i_cbp_luma == 0x00 && h->mb.i_cbp_chroma== 0x00 )
    {
        if( h->mb.cache.ref[0][x264_scan8[0]] == 0 )
        {
            int mvp[2];

            x264_mb_predict_mv_pskip( h, mvp );
            if( h->mb.cache.mv[0][x264_scan8[0]][0] == mvp[0] &&
                h->mb.cache.mv[0][x264_scan8[0]][1] == mvp[1] )
            {
                h->mb.type[h->mb.i_mb_xy] = h->mb.i_type = P_SKIP;
                h->mb.qp[h->mb.i_mb_xy] = h->mb.i_last_qp;  /* Needed */
            }
        }
    }

    /* Check for B_SKIP */
    if( h->mb.i_type == B_DIRECT &&
        h->mb.i_cbp_luma == 0x00 && h->mb.i_cbp_chroma== 0x00 )
    {
        h->mb.type[h->mb.i_mb_xy] = h->mb.i_type = B_SKIP;
        h->mb.qp[h->mb.i_mb_xy] = h->mb.i_last_qp;  /* Needed */
    }
}

/*****************************************************************************
 * x264_macroblock_probe_skip:
 *  Check if the current MB could be encoded as a [PB]_SKIP (it supposes you use
 *  the previous QP
 *****************************************************************************/
int x264_macroblock_probe_skip( x264_t *h, int b_bidir )
{
    DECLARE_ALIGNED( int16_t, dct4x4[16][4][4], 16 );
    DECLARE_ALIGNED( int16_t, dct2x2[2][2], 16 );
    DECLARE_ALIGNED( int,     dctscan[16], 16 );

    int i_qp;
    int mvp[2];
    int ch;

    int i8x8, i4x4;
    int i_decimate_mb;

    /* quantization scale */
    i_qp = h->mb.qp[h->mb.i_mb_xy];

    if( !b_bidir )
    {
        /* Get the MV */
        x264_mb_predict_mv_pskip( h, mvp );
        mvp[0] = x264_clip3( mvp[0], h->mb.mv_min[0], h->mb.mv_max[0] );
        mvp[1] = x264_clip3( mvp[1], h->mb.mv_min[1], h->mb.mv_max[1] );

        /* Motion compensation */
        h->mc.mc_luma( h->mb.pic.p_fref[0][0], h->mb.pic.i_stride[0],
                        h->mb.pic.p_fdec[0],   h->mb.pic.i_stride[0],
                        mvp[0], mvp[1], 16, 16 );
    }

    /* get luma diff */
    h->dctf.sub16x16_dct( dct4x4, h->mb.pic.p_fenc[0], h->mb.pic.i_stride[0],
                                  h->mb.pic.p_fdec[0], h->mb.pic.i_stride[0] );

    for( i8x8 = 0, i_decimate_mb = 0; i8x8 < 4; i8x8++ )
    {
        /* encode one 4x4 block */
        for( i4x4 = 0; i4x4 < 4; i4x4++ )
        {
            const int idx = i8x8 * 4 + i4x4;

            quant_4x4( dct4x4[idx], i_qp, 0 );
            scan_zigzag_4x4full( dctscan, dct4x4[idx] );

            i_decimate_mb += x264_mb_decimate_score( dctscan, 16 );

            if( i_decimate_mb >= 6 )
            {
                /* not as P_SKIP */
                return 0;
            }
        }
    }

    /* encode chroma */
    i_qp = i_chroma_qp_table[x264_clip3( i_qp + h->pps->i_chroma_qp_index_offset, 0, 51 )];

    for( ch = 0; ch < 2; ch++ )
    {
        const int i_stride = h->mb.pic.i_stride[1+ch];
        uint8_t  *p_src = h->mb.pic.p_fenc[1+ch];
        uint8_t  *p_dst = h->mb.pic.p_fdec[1+ch];

        if( !b_bidir )
        {
            h->mc.mc_chroma( h->mb.pic.p_fref[0][0][4+ch], i_stride,
                              h->mb.pic.p_fdec[1+ch],       i_stride,
                              mvp[0], mvp[1], 8, 8 );
        }

        h->dctf.sub8x8_dct( dct4x4, p_src, i_stride, p_dst, i_stride );

        /* calculate dct DC */
        dct2x2[0][0] = dct4x4[0][0][0];
        dct2x2[0][1] = dct4x4[1][0][0];
        dct2x2[1][0] = dct4x4[2][0][0];
        dct2x2[1][1] = dct4x4[3][0][0];
        h->dctf.dct2x2dc( dct2x2 );
        quant_2x2_dc( dct2x2, i_qp, 0 );
        if( dct2x2[0][0] || dct2x2[0][1] || dct2x2[1][0] || dct2x2[1][1]  )
        {
            /* can't be */
            return 0;
        }

        /* calculate dct coeffs */
        for( i4x4 = 0, i_decimate_mb = 0; i4x4 < 4; i4x4++ )
        {
            quant_4x4( dct4x4[i4x4], i_qp, 0 );
            scan_zigzag_4x4( dctscan, dct4x4[i4x4] );

            i_decimate_mb += x264_mb_decimate_score( dctscan, 15 );
            if( i_decimate_mb >= 7 )
            {
                return 0;
            }
        }
    }

    return 1;
}