/*****************************************************************************
 * cavlc.c: h264 encoder library
 *****************************************************************************
 * Copyright (C) 2003 Laurent Aimar
 * $Id: cavlc.c,v 1.1 2004/06/03 19:27:08 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.
 *****************************************************************************/

#include "common/common.h"
#include "common/vlc.h"
#include "macroblock.h"

static const uint8_t intra4x4_cbp_to_golomb[48]=
{
  3, 29, 30, 17, 31, 18, 37,  8, 32, 38, 19,  9, 20, 10, 11,  2,
 16, 33, 34, 21, 35, 22, 39,  4, 36, 40, 23,  5, 24,  6,  7,  1,
 41, 42, 43, 25, 44, 26, 46, 12, 45, 47, 27, 13, 28, 14, 15,  0
};
static const uint8_t inter_cbp_to_golomb[48]=
{
  0,  2,  3,  7,  4,  8, 17, 13,  5, 18,  9, 14, 10, 15, 16, 11,
  1, 32, 33, 36, 34, 37, 44, 40, 35, 45, 38, 41, 39, 42, 43, 19,
  6, 24, 25, 20, 26, 21, 46, 28, 27, 47, 22, 29, 23, 30, 31, 12
};
static const uint8_t mb_type_b_to_golomb[3][9]=
{
    { 4,  8, 12, 10,  6, 14, 16, 18, 20 }, /* D_16x8 */
    { 5,  9, 13, 11,  7, 15, 17, 19, 21 }, /* D_8x16 */
    { 1, -1, -1, -1,  2, -1, -1, -1,  3 }  /* D_16x16 */
};
static const uint8_t sub_mb_type_p_to_golomb[4]=
{
    3, 1, 2, 0
};
static const uint8_t sub_mb_type_b_to_golomb[13]=
{
    10,  4,  5,  1, 11,  6,  7,  2, 12,  8,  9,  3,  0
};

#define BLOCK_INDEX_CHROMA_DC   (-1)
#define BLOCK_INDEX_LUMA_DC     (-2)

static inline void bs_write_vlc( bs_t *s, vlc_t v )
{
    bs_write( s, v.i_size, v.i_bits );
}

/****************************************************************************
 * block_residual_write_cavlc:
 ****************************************************************************/
static void block_residual_write_cavlc( x264_t *h, bs_t *s, int i_idx, int *l, int i_count )
{
    int level[16], run[16];
    int i_total, i_trailing;
    int i_total_zero;
    int i_last;
    unsigned int i_sign;

    int i;
    int i_zero_left;
    int i_suffix_length;

    /* first find i_last */
    i_last = i_count - 1;
    while( i_last >= 0 && l[i_last] == 0 )
    {
        i_last--;
    }

    i_sign = 0;
    i_total = 0;
    i_trailing = 0;
    i_total_zero = i_last + 1;

    if( i_last >= 0 )
    {
        int idx = 0;

        /* level and run and total */
        while( i_last >= 0 )
        {
            level[idx] = l[i_last--];

            run[idx] = 0;
            while( i_last >= 0 && l[i_last] == 0 )
            {
                run[idx]++;
                i_last--;
            }

            idx++;
        }

        i_total = idx;
        i_total_zero -= idx;

        i_trailing = X264_MIN(3, idx);
        for( idx = 0; idx < i_trailing; idx++ )
        {
            if( abs(level[idx]) > 1 )
            {
                i_trailing = idx;
                break;
            }
            i_sign <<= 1;
            i_sign |= level[idx] < 0;
        }
    }

    /* total/trailing */
    if( i_idx == BLOCK_INDEX_CHROMA_DC )
    {
        bs_write_vlc( s, x264_coeff_token[4][i_total*4+i_trailing] );
    }
    else
    {
        /* x264_mb_predict_non_zero_code return 0 <-> (16+16+1)>>1 = 16 */
        static const int ct_index[17] = {0,0,1,1,2,2,2,2,3,3,3,3,3,3,3,3,3 };
        int nC = x264_mb_predict_non_zero_code( h, i_idx == BLOCK_INDEX_LUMA_DC ? 0 : i_idx );
        bs_write_vlc( s, x264_coeff_token[ct_index[nC]][i_total*4+i_trailing] );
    }

    if( i_total <= 0 )
    {
        return;
    }

    i_suffix_length = i_total > 10 && i_trailing < 3 ? 1 : 0;
    if( i_trailing > 0 )
    {
        bs_write( s, i_trailing, i_sign );
    }
    for( i = i_trailing; i < i_total; i++ )
    {
        unsigned int i_level_code;

        /* calculate level code */
        if( level[i] < 0 )
        {
            i_level_code = -2*level[i] - 1;
        }
        else /* if( level[i] > 0 ) */
        {
            i_level_code = 2 * level[i] - 2;
        }
        if( i == i_trailing && i_trailing < 3 )
        {
            i_level_code -= 2; /* as level[i] can't be 1 for the first one if i_trailing < 3 */
        }

        if( ( i_level_code >> i_suffix_length ) < 14 )
        {
            bs_write_vlc( s, x264_level_prefix[i_level_code >> i_suffix_length] );
            if( i_suffix_length > 0 )
            {
                bs_write( s, i_suffix_length, i_level_code );
            }
        }
        else if( i_suffix_length == 0 && i_level_code < 30 )
        {
            bs_write_vlc( s, x264_level_prefix[14] );
            bs_write( s, 4, i_level_code - 14 );
        }
        else if( i_suffix_length > 0 && ( i_level_code >> i_suffix_length ) == 14 )
        {
            bs_write_vlc( s, x264_level_prefix[14] );
            bs_write( s, i_suffix_length, i_level_code );
        }
        else
        {
            bs_write_vlc( s, x264_level_prefix[15] );
            i_level_code -= 15 << i_suffix_length;
            if( i_suffix_length == 0 )
            {
                i_level_code -= 15;
            }

            if( i_level_code >= 1<<12 )
            {
                x264_log(h, X264_LOG_WARNING, "OVERFLOW levelcode=%d\n", i_level_code );
            }

            bs_write( s, 12, i_level_code );
        }

        if( i_suffix_length == 0 )
        {
            i_suffix_length++;
        }
        if( abs( level[i] ) > ( 3 << ( i_suffix_length - 1 ) ) && i_suffix_length < 6 )
        {
            i_suffix_length++;
        }
    }

    if( i_total < i_count )
    {
        if( i_idx == BLOCK_INDEX_CHROMA_DC )
        {
            bs_write_vlc( s, x264_total_zeros_dc[i_total-1][i_total_zero] );
        }
        else
        {
            bs_write_vlc( s, x264_total_zeros[i_total-1][i_total_zero] );
        }
    }

    for( i = 0, i_zero_left = i_total_zero; i < i_total - 1; i++ )
    {
        int i_zl;

        if( i_zero_left <= 0 )
        {
            break;
        }

        i_zl = X264_MIN( i_zero_left - 1, 6 );

        bs_write_vlc( s, x264_run_before[i_zl][run[i]] );

        i_zero_left -= run[i];
    }
}

static void cavlc_qp_delta( x264_t *h, bs_t *s )
{
    int i_dqp = h->mb.i_qp - h->mb.i_last_qp;
    if( i_dqp )
    {
        if( i_dqp < -26 )
            i_dqp += 52;
        else if( i_dqp > 25 )
            i_dqp -= 52;
    }
    bs_write_se( s, i_dqp );
}

static void cavlc_mb_mvd( x264_t *h, bs_t *s, int i_list, int idx, int width )
{
    int mvp[2];
    x264_mb_predict_mv( h, i_list, idx, width, mvp );
    bs_write_se( s, h->mb.cache.mv[i_list][x264_scan8[idx]][0] - mvp[0] );
    bs_write_se( s, h->mb.cache.mv[i_list][x264_scan8[idx]][1] - mvp[1] );
}

static void cavlc_mb8x8_mvd( x264_t *h, bs_t *s, int i_list, int i )
{
    if( !x264_mb_partition_listX_table[i_list][ h->mb.i_sub_partition[i] ] )
        return;

    switch( h->mb.i_sub_partition[i] )
    {
        case D_L0_8x8:
        case D_L1_8x8:
        case D_BI_8x8:
            cavlc_mb_mvd( h, s, i_list, 4*i, 2 );
            break;
        case D_L0_8x4:
        case D_L1_8x4:
        case D_BI_8x4:
            cavlc_mb_mvd( h, s, i_list, 4*i+0, 2 );
            cavlc_mb_mvd( h, s, i_list, 4*i+2, 2 );
            break;
        case D_L0_4x8:
        case D_L1_4x8:
        case D_BI_4x8:
            cavlc_mb_mvd( h, s, i_list, 4*i+0, 1 );
            cavlc_mb_mvd( h, s, i_list, 4*i+1, 1 );
            break;
        case D_L0_4x4:
        case D_L1_4x4:
        case D_BI_4x4:
            cavlc_mb_mvd( h, s, i_list, 4*i+0, 1 );
            cavlc_mb_mvd( h, s, i_list, 4*i+1, 1 );
            cavlc_mb_mvd( h, s, i_list, 4*i+2, 1 );
            cavlc_mb_mvd( h, s, i_list, 4*i+3, 1 );
            break;
    }
}

static inline void x264_macroblock_luma_write_cavlc( x264_t *h, bs_t *s, int i8start, int i8end )
{
    int i8, i4, i;
    if( h->mb.b_transform_8x8 )
    {
        /* shuffle 8x8 dct coeffs into 4x4 lists */
        for( i8 = i8start; i8 <= i8end; i8++ )
            if( h->mb.i_cbp_luma & (1 << i8) )
                for( i4 = 0; i4 < 4; i4++ )
                {
                    for( i = 0; i < 16; i++ )
                        h->dct.block[i4+i8*4].luma4x4[i] = h->dct.luma8x8[i8][i4+i*4];
                    h->mb.cache.non_zero_count[x264_scan8[i4+i8*4]] =
                        array_non_zero_count( h->dct.block[i4+i8*4].luma4x4, 16 );
                }
    }

    for( i8 = i8start; i8 <= i8end; i8++ )
        if( h->mb.i_cbp_luma & (1 << i8) )
            for( i4 = 0; i4 < 4; i4++ )
                block_residual_write_cavlc( h, s, i4+i8*4, h->dct.block[i4+i8*4].luma4x4, 16 );
}

/*****************************************************************************
 * x264_macroblock_write:
 *****************************************************************************/
void x264_macroblock_write_cavlc( x264_t *h, bs_t *s )
{
    const int i_mb_type = h->mb.i_type;
    int i_mb_i_offset;
    int i;

#ifndef RDO_SKIP_BS
    const int i_mb_pos_start = bs_pos( s );
    int       i_mb_pos_tex;
#endif

    switch( h->sh.i_type )
    {
        case SLICE_TYPE_I:
            i_mb_i_offset = 0;
            break;
        case SLICE_TYPE_P:
            i_mb_i_offset = 5;
            break;
        case SLICE_TYPE_B:
            i_mb_i_offset = 23;
            break;
        default:
            x264_log(h, X264_LOG_ERROR, "internal error or slice unsupported\n" );
            return;
    }

    if( h->sh.b_mbaff
        && (!(h->mb.i_mb_y & 1) || IS_SKIP(h->mb.type[h->mb.i_mb_xy - h->mb.i_mb_stride])) )
    {
        bs_write1( s, h->mb.b_interlaced );
    }

    /* Write:
      - type
      - prediction
      - mv */
    if( i_mb_type == I_PCM )
    {
        /* Untested */
        bs_write_ue( s, i_mb_i_offset + 25 );

#ifdef RDO_SKIP_BS
        s->i_bits_encoded += 384*8;
#else
        bs_align_0( s );
        /* 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] );
        }
#endif
        return;
    }
    else if( i_mb_type == I_4x4 || i_mb_type == I_8x8 )
    {
        int di = i_mb_type == I_8x8 ? 4 : 1;
        bs_write_ue( s, i_mb_i_offset + 0 );
        if( h->pps->b_transform_8x8_mode )
            bs_write1( s, h->mb.b_transform_8x8 );

        /* Prediction: Luma */
        for( i = 0; i < 16; i += di )
        {
            int i_pred = x264_mb_predict_intra4x4_mode( h, i );
            int i_mode = x264_mb_pred_mode4x4_fix( h->mb.cache.intra4x4_pred_mode[x264_scan8[i]] );

            if( i_pred == i_mode)
            {
                bs_write1( s, 1 );  /* b_prev_intra4x4_pred_mode */
            }
            else
            {
                bs_write1( s, 0 );  /* b_prev_intra4x4_pred_mode */
                if( i_mode < i_pred )
                {
                    bs_write( s, 3, i_mode );
                }
                else
                {
                    bs_write( s, 3, i_mode - 1 );
                }
            }
        }
        bs_write_ue( s, x264_mb_pred_mode8x8c_fix[ h->mb.i_chroma_pred_mode ] );
    }
    else if( i_mb_type == I_16x16 )
    {
        bs_write_ue( s, i_mb_i_offset + 1 + x264_mb_pred_mode16x16_fix[h->mb.i_intra16x16_pred_mode] +
                        h->mb.i_cbp_chroma * 4 + ( h->mb.i_cbp_luma == 0 ? 0 : 12 ) );
        bs_write_ue( s, x264_mb_pred_mode8x8c_fix[ h->mb.i_chroma_pred_mode ] );
    }
    else if( i_mb_type == P_L0 )
    {
        int mvp[2];

        if( h->mb.i_partition == D_16x16 )
        {
            bs_write_ue( s, 0 );

            if( h->mb.pic.i_fref[0] > 1 )
            {
                bs_write_te( s, h->mb.pic.i_fref[0] - 1, h->mb.cache.ref[0][x264_scan8[0]] );
            }
            x264_mb_predict_mv( h, 0, 0, 4, mvp );
            bs_write_se( s, h->mb.cache.mv[0][x264_scan8[0]][0] - mvp[0] );
            bs_write_se( s, h->mb.cache.mv[0][x264_scan8[0]][1] - mvp[1] );
        }
        else if( h->mb.i_partition == D_16x8 )
        {
            bs_write_ue( s, 1 );
            if( h->mb.pic.i_fref[0] > 1 )
            {
                bs_write_te( s, h->mb.pic.i_fref[0] - 1, h->mb.cache.ref[0][x264_scan8[0]] );
                bs_write_te( s, h->mb.pic.i_fref[0] - 1, h->mb.cache.ref[0][x264_scan8[8]] );
            }

            x264_mb_predict_mv( h, 0, 0, 4, mvp );
            bs_write_se( s, h->mb.cache.mv[0][x264_scan8[0]][0] - mvp[0] );
            bs_write_se( s, h->mb.cache.mv[0][x264_scan8[0]][1] - mvp[1] );

            x264_mb_predict_mv( h, 0, 8, 4, mvp );
            bs_write_se( s, h->mb.cache.mv[0][x264_scan8[8]][0] - mvp[0] );
            bs_write_se( s, h->mb.cache.mv[0][x264_scan8[8]][1] - mvp[1] );
        }
        else if( h->mb.i_partition == D_8x16 )
        {
            bs_write_ue( s, 2 );
            if( h->mb.pic.i_fref[0] > 1 )
            {
                bs_write_te( s, h->mb.pic.i_fref[0] - 1, h->mb.cache.ref[0][x264_scan8[0]] );
                bs_write_te( s, h->mb.pic.i_fref[0] - 1, h->mb.cache.ref[0][x264_scan8[4]] );
            }

            x264_mb_predict_mv( h, 0, 0, 2, mvp );
            bs_write_se( s, h->mb.cache.mv[0][x264_scan8[0]][0] - mvp[0] );
            bs_write_se( s, h->mb.cache.mv[0][x264_scan8[0]][1] - mvp[1] );

            x264_mb_predict_mv( h, 0, 4, 2, mvp );
            bs_write_se( s, h->mb.cache.mv[0][x264_scan8[4]][0] - mvp[0] );
            bs_write_se( s, h->mb.cache.mv[0][x264_scan8[4]][1] - mvp[1] );
        }
    }
    else if( i_mb_type == P_8x8 )
    {
        int b_sub_ref0;

        if( h->mb.cache.ref[0][x264_scan8[0]] == 0 && h->mb.cache.ref[0][x264_scan8[4]] == 0 &&
            h->mb.cache.ref[0][x264_scan8[8]] == 0 && h->mb.cache.ref[0][x264_scan8[12]] == 0 )
        {
            bs_write_ue( s, 4 );
            b_sub_ref0 = 0;
        }
        else
        {
            bs_write_ue( s, 3 );
            b_sub_ref0 = 1;
        }
        /* sub mb type */
        for( i = 0; i < 4; i++ )
        {
            bs_write_ue( s, sub_mb_type_p_to_golomb[ h->mb.i_sub_partition[i] ] );
        }
        /* ref0 */
        if( h->mb.pic.i_fref[0] > 1 && b_sub_ref0 )
        {
            bs_write_te( s, h->mb.pic.i_fref[0] - 1, h->mb.cache.ref[0][x264_scan8[0]] );
            bs_write_te( s, h->mb.pic.i_fref[0] - 1, h->mb.cache.ref[0][x264_scan8[4]] );
            bs_write_te( s, h->mb.pic.i_fref[0] - 1, h->mb.cache.ref[0][x264_scan8[8]] );
            bs_write_te( s, h->mb.pic.i_fref[0] - 1, h->mb.cache.ref[0][x264_scan8[12]] );
        }

        for( i = 0; i < 4; i++ )
            cavlc_mb8x8_mvd( h, s, 0, i );
    }
    else if( i_mb_type == B_8x8 )
    {
        bs_write_ue( s, 22 );

        /* sub mb type */
        for( i = 0; i < 4; i++ )
        {
            bs_write_ue( s, sub_mb_type_b_to_golomb[ h->mb.i_sub_partition[i] ] );
        }
        /* ref */
        for( i = 0; i < 4; i++ )
        {
            if( x264_mb_partition_listX_table[0][ h->mb.i_sub_partition[i] ] )
            {
                bs_write_te( s, h->mb.pic.i_fref[0] - 1, h->mb.cache.ref[0][x264_scan8[i*4]] );
            }
        }
        for( i = 0; i < 4; i++ )
        {
            if( x264_mb_partition_listX_table[1][ h->mb.i_sub_partition[i] ] )
            {
                bs_write_te( s, h->mb.pic.i_fref[1] - 1, h->mb.cache.ref[1][x264_scan8[i*4]] );
            }
        }
        /* mvd */
        for( i = 0; i < 4; i++ )
            cavlc_mb8x8_mvd( h, s, 0, i );
        for( i = 0; i < 4; i++ )
            cavlc_mb8x8_mvd( h, s, 1, i );
    }
    else if( i_mb_type != B_DIRECT )
    {
        /* All B mode */
        /* Motion Vector */
        int i_list;
        int mvp[2];

        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];
        }


        bs_write_ue( s, mb_type_b_to_golomb[ h->mb.i_partition - D_16x8 ][ i_mb_type - B_L0_L0 ] );

        for( i_list = 0; i_list < 2; i_list++ )
        {
            const int i_ref_max = i_list == 0 ? h->mb.pic.i_fref[0] : h->mb.pic.i_fref[1];

            if( i_ref_max > 1 )
            {
                switch( h->mb.i_partition )
                {
                    case D_16x16:
                        if( b_list[i_list][0] ) bs_write_te( s, i_ref_max - 1, h->mb.cache.ref[i_list][x264_scan8[0]] );
                        break;
                    case D_16x8:
                        if( b_list[i_list][0] ) bs_write_te( s, i_ref_max - 1, h->mb.cache.ref[i_list][x264_scan8[0]] );
                        if( b_list[i_list][1] ) bs_write_te( s, i_ref_max - 1, h->mb.cache.ref[i_list][x264_scan8[8]] );
                        break;
                    case D_8x16:
                        if( b_list[i_list][0] ) bs_write_te( s, i_ref_max - 1, h->mb.cache.ref[i_list][x264_scan8[0]] );
                        if( b_list[i_list][1] ) bs_write_te( s, i_ref_max - 1, h->mb.cache.ref[i_list][x264_scan8[4]] );
                        break;
                }
            }
        }
        for( i_list = 0; i_list < 2; i_list++ )
        {
            switch( h->mb.i_partition )
            {
                case D_16x16:
                    if( b_list[i_list][0] )
                    {
                        x264_mb_predict_mv( h, i_list, 0, 4, mvp );
                        bs_write_se( s, h->mb.cache.mv[i_list][x264_scan8[0]][0] - mvp[0] );
                        bs_write_se( s, h->mb.cache.mv[i_list][x264_scan8[0]][1] - mvp[1] );
                    }
                    break;
                case D_16x8:
                    if( b_list[i_list][0] )
                    {
                        x264_mb_predict_mv( h, i_list, 0, 4, mvp );
                        bs_write_se( s, h->mb.cache.mv[i_list][x264_scan8[0]][0] - mvp[0] );
                        bs_write_se( s, h->mb.cache.mv[i_list][x264_scan8[0]][1] - mvp[1] );
                    }
                    if( b_list[i_list][1] )
                    {
                        x264_mb_predict_mv( h, i_list, 8, 4, mvp );
                        bs_write_se( s, h->mb.cache.mv[i_list][x264_scan8[8]][0] - mvp[0] );
                        bs_write_se( s, h->mb.cache.mv[i_list][x264_scan8[8]][1] - mvp[1] );
                    }
                    break;
                case D_8x16:
                    if( b_list[i_list][0] )
                    {
                        x264_mb_predict_mv( h, i_list, 0, 2, mvp );
                        bs_write_se( s, h->mb.cache.mv[i_list][x264_scan8[0]][0] - mvp[0] );
                        bs_write_se( s, h->mb.cache.mv[i_list][x264_scan8[0]][1] - mvp[1] );
                    }
                    if( b_list[i_list][1] )
                    {
                        x264_mb_predict_mv( h, i_list, 4, 2, mvp );
                        bs_write_se( s, h->mb.cache.mv[i_list][x264_scan8[4]][0] - mvp[0] );
                        bs_write_se( s, h->mb.cache.mv[i_list][x264_scan8[4]][1] - mvp[1] );
                    }
                    break;
            }
        }
    }
    else if( i_mb_type == B_DIRECT )
    {
        bs_write_ue( s, 0 );
    }
    else
    {
        x264_log(h, X264_LOG_ERROR, "invalid/unhandled mb_type\n" );
        return;
    }

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

    /* Coded block patern */
    if( i_mb_type == I_4x4 || i_mb_type == I_8x8 )
    {
        bs_write_ue( s, intra4x4_cbp_to_golomb[( h->mb.i_cbp_chroma << 4 )|h->mb.i_cbp_luma] );
    }
    else if( i_mb_type != I_16x16 )
    {
        bs_write_ue( s, inter_cbp_to_golomb[( h->mb.i_cbp_chroma << 4 )|h->mb.i_cbp_luma] );
    }

    /* transform size 8x8 flag */
    if( h->mb.cache.b_transform_8x8_allowed && h->mb.i_cbp_luma && !IS_INTRA(i_mb_type) )
    {
        bs_write1( s, h->mb.b_transform_8x8 );
    }

    /* write residual */
    if( i_mb_type == I_16x16 )
    {
        cavlc_qp_delta( h, s );

        /* DC Luma */
        block_residual_write_cavlc( h, s, BLOCK_INDEX_LUMA_DC , h->dct.luma16x16_dc, 16 );

        /* AC Luma */
        if( h->mb.i_cbp_luma != 0 )
            for( i = 0; i < 16; i++ )
                block_residual_write_cavlc( h, s, i, h->dct.block[i].residual_ac, 15 );
    }
    else if( h->mb.i_cbp_luma != 0 || h->mb.i_cbp_chroma != 0 )
    {
        cavlc_qp_delta( h, s );
        x264_macroblock_luma_write_cavlc( h, s, 0, 3 );
    }
    if( h->mb.i_cbp_chroma != 0 )
    {
        /* Chroma DC residual present */
        block_residual_write_cavlc( h, s, BLOCK_INDEX_CHROMA_DC, h->dct.chroma_dc[0], 4 );
        block_residual_write_cavlc( h, s, BLOCK_INDEX_CHROMA_DC, 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_cavlc( h, s, 16 + 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 += bs_pos(s) - i_mb_pos_tex;
    else
        h->stat.frame.i_ptex_bits += bs_pos(s) - i_mb_pos_tex;
#endif
}

#ifdef RDO_SKIP_BS
/*****************************************************************************
 * RD only; doesn't generate a valid bitstream
 * doesn't write cbp or chroma dc (I don't know how much this matters)
 * works on all partition sizes except 16x16
 * for sub8x8, call once per 8x8 block
 *****************************************************************************/
int x264_partition_size_cavlc( x264_t *h, int i8, int i_pixel )
{
    bs_t s;
    const int i_mb_type = h->mb.i_type;
    int j;

    s.i_bits_encoded = 0;

    if( i_mb_type == P_8x8 )
    {
        bs_write_ue( &s, sub_mb_type_p_to_golomb[ h->mb.i_sub_partition[i8] ] );
        if( h->mb.pic.i_fref[0] > 1 )
            bs_write_te( &s, h->mb.pic.i_fref[0] - 1, h->mb.cache.ref[0][x264_scan8[4*i8]] );
        cavlc_mb8x8_mvd( h, &s, 0, i8 );
    }
    else if( i_mb_type == P_L0 )
    {
        if( h->mb.pic.i_fref[0] > 1 )
            bs_write_te( &s, h->mb.pic.i_fref[0] - 1, h->mb.cache.ref[0][x264_scan8[4*i8]] );
        if( h->mb.i_partition == D_16x8 )
            cavlc_mb_mvd( h, &s, 0, 4*i8, 4 );
        else //8x16
            cavlc_mb_mvd( h, &s, 0, 4*i8, 2 );
    }
    else if( i_mb_type == B_8x8 )
    {
        bs_write_ue( &s, sub_mb_type_b_to_golomb[ h->mb.i_sub_partition[i8] ] );

        if( h->mb.pic.i_fref[0] > 1
            && x264_mb_partition_listX_table[0][ h->mb.i_sub_partition[i8] ] )
            bs_write_te( &s, h->mb.pic.i_fref[0] - 1, h->mb.cache.ref[0][x264_scan8[4*i8]] );
        if( h->mb.pic.i_fref[1] > 1
            && x264_mb_partition_listX_table[1][ h->mb.i_sub_partition[i8] ] )
            bs_write_te( &s, h->mb.pic.i_fref[1] - 1, h->mb.cache.ref[1][x264_scan8[4*i8]] );

        cavlc_mb8x8_mvd( h, &s, 0, i8 );
        cavlc_mb8x8_mvd( h, &s, 1, i8 );
    }
    else
    {
        x264_log(h, X264_LOG_ERROR, "invalid/unhandled mb_type\n" );
        return 0;
    }

    for( j = (i_pixel < PIXEL_8x8); j >= 0; j-- )
    {
        x264_macroblock_luma_write_cavlc( h, &s, i8, i8 );

        block_residual_write_cavlc( h, &s, i8,   h->dct.block[16+i8  ].residual_ac, 15 );
        block_residual_write_cavlc( h, &s, i8+4, h->dct.block[16+i8+4].residual_ac, 15 );

        i8 += x264_pixel_size[i_pixel].h >> 3;
    }

    return s.i_bits_encoded;
}

static int cavlc_intra4x4_pred_size( x264_t *h, int i4, int i_mode )
{
    if( x264_mb_predict_intra4x4_mode( h, i4 ) == x264_mb_pred_mode4x4_fix( i_mode ) )
        return 1;
    else
        return 4;
}

static int x264_partition_i8x8_size_cavlc( x264_t *h, int i8, int i_mode )
{
    int i4, i;
    h->out.bs.i_bits_encoded = cavlc_intra4x4_pred_size( h, 4*i8, i_mode );
    for( i4 = 0; i4 < 4; i4++ )
    {
        for( i = 0; i < 16; i++ )
            h->dct.block[i4+i8*4].luma4x4[i] = h->dct.luma8x8[i8][i4+i*4];
        h->mb.cache.non_zero_count[x264_scan8[i4+i8*4]] =
            array_non_zero_count( h->dct.block[i4+i8*4].luma4x4, 16 );
        block_residual_write_cavlc( h, &h->out.bs, i4+i8*4, h->dct.block[i4+i8*4].luma4x4, 16 );
    }
    return h->out.bs.i_bits_encoded;
}

static int x264_partition_i4x4_size_cavlc( x264_t *h, int i4, int i_mode )
{
    h->out.bs.i_bits_encoded = cavlc_intra4x4_pred_size( h, i4, i_mode );
    block_residual_write_cavlc( h, &h->out.bs, i4, h->dct.block[i4].luma4x4, 16 );
    return h->out.bs.i_bits_encoded;
}

static int x264_i8x8_chroma_size_cavlc( x264_t *h )
{
    h->out.bs.i_bits_encoded = bs_size_ue( x264_mb_pred_mode8x8c_fix[ h->mb.i_chroma_pred_mode ] );
    if( h->mb.i_cbp_chroma != 0 )
    {
        block_residual_write_cavlc( h, &h->out.bs, BLOCK_INDEX_CHROMA_DC, h->dct.chroma_dc[0], 4 );
        block_residual_write_cavlc( h, &h->out.bs, BLOCK_INDEX_CHROMA_DC, h->dct.chroma_dc[1], 4 );

        if( h->mb.i_cbp_chroma == 2 )
        {
            int i;
            for( i = 0; i < 8; i++ )
                block_residual_write_cavlc( h, &h->out.bs, 16 + i, h->dct.block[16+i].residual_ac, 15 );
        }
    }
    return h->out.bs.i_bits_encoded;
}
#endif
