cabac.c.svn-base

现在关于h.264的源码很多

    7, 6,11,12,13,11, 6, 7, 8, 9,14,10, 9, 8, 6,11,
   12,13,11, 6, 9,14,10, 9,11,12,13,11,14,10,12
};
static const int last_coeff_flag_offset_8x8[63] = {
    0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
    2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
    3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4,
    5, 5, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8
};

static void block_residual_write_cabac( x264_t *h, x264_cabac_t *cb, int i_ctxBlockCat, int i_idx, int *l, int i_count )
{
    const int i_ctx_sig = significant_coeff_flag_offset[i_ctxBlockCat];
    const int i_ctx_last = last_coeff_flag_offset[i_ctxBlockCat];
    const int i_ctx_level = coeff_abs_level_m1_offset[i_ctxBlockCat];

    int i_coeff_abs_m1[64];
    int i_coeff_sign[64];
    int i_coeff = 0;
    int i_last  = 0;
    int i_sigmap_size;

    int i_abslevel1 = 0;
    int i_abslevelgt1 = 0;

    int i;

    /* i_ctxBlockCat: 0-> DC 16x16  i_idx = 0
     *                1-> AC 16x16  i_idx = luma4x4idx
     *                2-> Luma4x4   i_idx = luma4x4idx
     *                3-> DC Chroma i_idx = iCbCr
     *                4-> AC Chroma i_idx = 4 * iCbCr + chroma4x4idx
     *                5-> Luma8x8   i_idx = luma8x8idx
     */

    for( i = 0; i < i_count; i++ )
    {
        if( l[i] != 0 )
        {
            i_coeff_abs_m1[i_coeff] = abs( l[i] ) - 1;
            i_coeff_sign[i_coeff]   = ( l[i] < 0 );
            i_coeff++;

            i_last = i;
        }
    }

    if( i_count != 64 )
    {
        /* coded block flag */
        x264_cabac_encode_decision( cb, 85 + x264_cabac_mb_cbf_ctxidxinc( h, i_ctxBlockCat, i_idx ), i_coeff != 0 );
        if( i_coeff == 0 )
            return;
    }

    i_sigmap_size = X264_MIN( i_last+1, i_count-1 );
    for( i = 0; i < i_sigmap_size; i++ )
    {
        int i_sig_ctxIdxInc;
        int i_last_ctxIdxInc;

        if( i_ctxBlockCat == DCT_LUMA_8x8 )
        {
            i_sig_ctxIdxInc = significant_coeff_flag_offset_8x8[i];
            i_last_ctxIdxInc = last_coeff_flag_offset_8x8[i];
        }
        else
            i_sig_ctxIdxInc = i_last_ctxIdxInc = i;

        x264_cabac_encode_decision( cb, i_ctx_sig + i_sig_ctxIdxInc, l[i] != 0 );
        if( l[i] != 0 )
            x264_cabac_encode_decision( cb, i_ctx_last + i_last_ctxIdxInc, i == i_last );
    }

    for( i = i_coeff - 1; i >= 0; i-- )
    {
        /* write coeff_abs - 1 */
        const int i_prefix = X264_MIN( i_coeff_abs_m1[i], 14 );
        const int i_ctxIdxInc = (i_abslevelgt1 ? 0 : X264_MIN( 4, i_abslevel1 + 1 )) + i_ctx_level;
        x264_cabac_encode_decision( cb, i_ctxIdxInc, i_prefix != 0 );

        if( i_prefix != 0 )
        {
            const int i_ctxIdxInc = 5 + X264_MIN( 4, i_abslevelgt1 ) + i_ctx_level;
            int j;
            for( j = 0; j < i_prefix - 1; j++ )
                x264_cabac_encode_decision( cb, i_ctxIdxInc, 1 );
            if( i_prefix < 14 )
                x264_cabac_encode_decision( cb, i_ctxIdxInc, 0 );
            else /* suffix */
                x264_cabac_encode_ue_bypass( cb, 0, i_coeff_abs_m1[i] - 14 );

            i_abslevelgt1++;
        }
        else
            i_abslevel1++;

        /* write sign */
        x264_cabac_encode_bypass( cb, i_coeff_sign[i] );
    }
}



void x264_macroblock_write_cabac( x264_t *h, x264_cabac_t *cb )
{
    const int i_mb_type = h->mb.i_type;
    int i_list;
    int i;

#ifndef RDO_SKIP_BS
    const int i_mb_pos_start = x264_cabac_pos( cb );
    int       i_mb_pos_tex;
#endif

    /* Write the MB type */
    x264_cabac_mb_type( h, cb );

    /* PCM special block type UNTESTED */
    if( i_mb_type == I_PCM )
    {
#ifdef RDO_SKIP_BS
        cb->f8_bits_encoded += (384*8) << 8;
#else
        bs_t *s = cb->s;
        bs_align_0( s );    /* not sure */
        /* Luma */
        for( i = 0; i < 16*16; i++ )
        {
            const int x = 16 * h->mb.i_mb_x + (i % 16);
            const int y = 16 * h->mb.i_mb_y + (i / 16);
            bs_write( s, 8, h->fenc->plane[0][y*h->mb.pic.i_stride[0]+x] );
        }
        /* Cb */
        for( i = 0; i < 8*8; i++ )
        {
            const int x = 8 * h->mb.i_mb_x + (i % 8);
            const int y = 8 * h->mb.i_mb_y + (i / 8);
            bs_write( s, 8, h->fenc->plane[1][y*h->mb.pic.i_stride[1]+x] );
        }
        /* Cr */
        for( i = 0; i < 8*8; i++ )
        {
            const int x = 8 * h->mb.i_mb_x + (i % 8);
            const int y = 8 * h->mb.i_mb_y + (i / 8);
            bs_write( s, 8, h->fenc->plane[2][y*h->mb.pic.i_stride[2]+x] );
        }
        x264_cabac_encode_init( cb, s );
#endif
        return;
    }

    if( IS_INTRA( i_mb_type ) )
    {
        if( h->pps->b_transform_8x8_mode && i_mb_type != I_16x16 )
            x264_cabac_mb_transform_size( h, cb );

        if( i_mb_type != I_16x16 )
        {
            int di = (i_mb_type == I_8x8) ? 4 : 1;
            for( i = 0; i < 16; i += di )
            {
                const int i_pred = x264_mb_predict_intra4x4_mode( h, i );
                const int i_mode = x264_mb_pred_mode4x4_fix( h->mb.cache.intra4x4_pred_mode[x264_scan8[i]] );
                x264_cabac_mb_intra4x4_pred_mode( cb, i_pred, i_mode );
            }
        }

        x264_cabac_mb_intra_chroma_pred_mode( h, cb );
    }
    else if( i_mb_type == P_L0 )
    {
        if( h->mb.i_partition == D_16x16 )
        {
            if( h->sh.i_num_ref_idx_l0_active > 1 )
            {
                x264_cabac_mb_ref( h, cb, 0, 0 );
            }
            x264_cabac_mb_mvd( h, cb, 0, 0, 4, 4 );
        }
        else if( h->mb.i_partition == D_16x8 )
        {
            if( h->sh.i_num_ref_idx_l0_active > 1 )
            {
                x264_cabac_mb_ref( h, cb, 0, 0 );
                x264_cabac_mb_ref( h, cb, 0, 8 );
            }
            x264_cabac_mb_mvd( h, cb, 0, 0, 4, 2 );
            x264_cabac_mb_mvd( h, cb, 0, 8, 4, 2 );
        }
        else if( h->mb.i_partition == D_8x16 )
        {
            if( h->sh.i_num_ref_idx_l0_active > 1 )
            {
                x264_cabac_mb_ref( h, cb, 0, 0 );
                x264_cabac_mb_ref( h, cb, 0, 4 );
            }
            x264_cabac_mb_mvd( h, cb, 0, 0, 2, 4 );
            x264_cabac_mb_mvd( h, cb, 0, 4, 2, 4 );
        }
    }
    else if( i_mb_type == P_8x8 )
    {
        /* sub mb type */
        x264_cabac_mb_sub_p_partition( cb, h->mb.i_sub_partition[0] );
        x264_cabac_mb_sub_p_partition( cb, h->mb.i_sub_partition[1] );
        x264_cabac_mb_sub_p_partition( cb, h->mb.i_sub_partition[2] );
        x264_cabac_mb_sub_p_partition( cb, h->mb.i_sub_partition[3] );

        /* ref 0 */
        if( h->sh.i_num_ref_idx_l0_active > 1 )
        {
            x264_cabac_mb_ref( h, cb, 0, 0 );
            x264_cabac_mb_ref( h, cb, 0, 4 );
            x264_cabac_mb_ref( h, cb, 0, 8 );
            x264_cabac_mb_ref( h, cb, 0, 12 );
        }

        x264_cabac_mb8x8_mvd( h, cb, 0 );
    }
    else if( i_mb_type == B_8x8 )
    {
        /* sub mb type */
        x264_cabac_mb_sub_b_partition( cb, h->mb.i_sub_partition[0] );
        x264_cabac_mb_sub_b_partition( cb, h->mb.i_sub_partition[1] );
        x264_cabac_mb_sub_b_partition( cb, h->mb.i_sub_partition[2] );
        x264_cabac_mb_sub_b_partition( cb, h->mb.i_sub_partition[3] );

        /* ref */
        for( i_list = 0; i_list < 2; i_list++ )
        {
            if( ( i_list ? h->sh.i_num_ref_idx_l1_active : h->sh.i_num_ref_idx_l0_active ) == 1 )
                continue;
            for( i = 0; i < 4; i++ )
                if( x264_mb_partition_listX_table[i_list][ h->mb.i_sub_partition[i] ] )
                    x264_cabac_mb_ref( h, cb, i_list, 4*i );
        }

        x264_cabac_mb8x8_mvd( h, cb, 0 );
        x264_cabac_mb8x8_mvd( h, cb, 1 );
    }
    else if( i_mb_type != B_DIRECT )
    {
        /* All B mode */
        int b_list[2][2];

        /* init ref list utilisations */
        for( i = 0; i < 2; i++ )
        {
            b_list[0][i] = x264_mb_type_list0_table[i_mb_type][i];
            b_list[1][i] = x264_mb_type_list1_table[i_mb_type][i];
        }

        for( i_list = 0; i_list < 2; i_list++ )
        {
            const int i_ref_max = i_list == 0 ? h->sh.i_num_ref_idx_l0_active : h->sh.i_num_ref_idx_l1_active;

            if( i_ref_max > 1 )
            {
                if( h->mb.i_partition == D_16x16 )
                {
                    if( b_list[i_list][0] ) x264_cabac_mb_ref( h, cb, i_list, 0 );
                }
                else if( h->mb.i_partition == D_16x8 )
                {
                    if( b_list[i_list][0] ) x264_cabac_mb_ref( h, cb, i_list, 0 );
                    if( b_list[i_list][1] ) x264_cabac_mb_ref( h, cb, i_list, 8 );
                }
                else if( h->mb.i_partition == D_8x16 )
                {
                    if( b_list[i_list][0] ) x264_cabac_mb_ref( h, cb, i_list, 0 );
                    if( b_list[i_list][1] ) x264_cabac_mb_ref( h, cb, i_list, 4 );
                }
            }
        }
        for( i_list = 0; i_list < 2; i_list++ )
        {
            if( h->mb.i_partition == D_16x16 )
            {
                if( b_list[i_list][0] ) x264_cabac_mb_mvd( h, cb, i_list, 0, 4, 4 );
            }
            else if( h->mb.i_partition == D_16x8 )
            {
                if( b_list[i_list][0] ) x264_cabac_mb_mvd( h, cb, i_list, 0, 4, 2 );
                if( b_list[i_list][1] ) x264_cabac_mb_mvd( h, cb, i_list, 8, 4, 2 );
            }
            else if( h->mb.i_partition == D_8x16 )
            {
                if( b_list[i_list][0] ) x264_cabac_mb_mvd( h, cb, i_list, 0, 2, 4 );
                if( b_list[i_list][1] ) x264_cabac_mb_mvd( h, cb, i_list, 4, 2, 4 );
            }
        }
    }

#ifndef RDO_SKIP_BS
    i_mb_pos_tex = x264_cabac_pos( cb );
    h->stat.frame.i_hdr_bits += i_mb_pos_tex - i_mb_pos_start;
#endif

    if( i_mb_type != I_16x16 )
    {
        x264_cabac_mb_cbp_luma( h, cb );
        x264_cabac_mb_cbp_chroma( h, cb );
    }

    if( h->mb.cache.b_transform_8x8_allowed && h->mb.i_cbp_luma && !IS_INTRA(i_mb_type) )
    {
        x264_cabac_mb_transform_size( h, cb );
    }

    if( h->mb.i_cbp_luma > 0 || h->mb.i_cbp_chroma > 0 || i_mb_type == I_16x16 )
    {
        x264_cabac_mb_qp_delta( h, cb );

        /* write residual */
        if( i_mb_type == I_16x16 )
        {
            /* DC Luma */
            block_residual_write_cabac( h, cb, DCT_LUMA_DC, 0, h->dct.luma16x16_dc, 16 );

            /* AC Luma */
            if( h->mb.i_cbp_luma != 0 )
                for( i = 0; i < 16; i++ )
                    block_residual_write_cabac( h, cb, DCT_LUMA_AC, i, h->dct.block[i].residual_ac, 15 );
        }
        else if( h->mb.b_transform_8x8 )
        {
            for( i = 0; i < 4; i++ )
                if( h->mb.i_cbp_luma & ( 1 << i ) )
                    block_residual_write_cabac( h, cb, DCT_LUMA_8x8, i, h->dct.luma8x8[i], 64 );
        }
        else
        {
            for( i = 0; i < 16; i++ )
                if( h->mb.i_cbp_luma & ( 1 << ( i / 4 ) ) )
                    block_residual_write_cabac( h, cb, DCT_LUMA_4x4, i, h->dct.block[i].luma4x4, 16 );
        }

        if( h->mb.i_cbp_chroma &0x03 )    /* Chroma DC residual present */
        {
            block_residual_write_cabac( h, cb, DCT_CHROMA_DC, 0, h->dct.chroma_dc[0], 4 );
            block_residual_write_cabac( h, cb, DCT_CHROMA_DC, 1, h->dct.chroma_dc[1], 4 );
        }
        if( h->mb.i_cbp_chroma&0x02 ) /* Chroma AC residual present */
        {
            for( i = 0; i < 8; i++ )
                block_residual_write_cabac( h, cb, DCT_CHROMA_AC, i, h->dct.block[16+i].residual_ac, 15 );
        }
    }

#ifndef RDO_SKIP_BS
    if( IS_INTRA( i_mb_type ) )
        h->stat.frame.i_itex_bits += x264_cabac_pos( cb ) - i_mb_pos_tex;
    else
        h->stat.frame.i_ptex_bits += x264_cabac_pos( cb ) - i_mb_pos_tex;
#endif
}