Commit message: None
CVE: CVE-2016-3742
CWE: CWE-20
Vulnerability description: decoder/ih264d_process_intra_mb.c in mediaserver in Android 6.x before 2016-07-01 mishandles intra mode, which allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted media file, aka internal bug 28165659.

Project: Android

WORD32 ih264d_process_intra_mb(dec_struct_t * ps_dec,
 dec_mb_info_t * ps_cur_mb_info,
                               UWORD8 u1_mb_num)
{
    UWORD8 u1_mb_type = ps_cur_mb_info->u1_mb_type;
    UWORD8 uc_temp = ps_cur_mb_info->u1_mb_ngbr_availablity;
    UWORD8 u1_top_available = BOOLEAN(uc_temp & TOP_MB_AVAILABLE_MASK);
    UWORD8 u1_left_available = BOOLEAN(uc_temp & LEFT_MB_AVAILABLE_MASK);
    UWORD8 u1_use_top_right_mb = BOOLEAN(uc_temp & TOP_RIGHT_MB_AVAILABLE_MASK);
    UWORD8 u1_use_top_left_mb = BOOLEAN(uc_temp & TOP_LEFT_MB_AVAILABLE_MASK);
    UWORD8 uc_useTopMB = u1_top_available;
    UWORD16 u2_use_left_mb = u1_left_available;
    UWORD16 u2_use_left_mb_pack;
    UWORD8 *pu1_luma_pred_buffer;
 /* CHANGED CODE */
    UWORD8 *pu1_luma_rec_buffer;
    UWORD8 *puc_top;

 mb_neigbour_params_t *ps_left_mb;
 mb_neigbour_params_t *ps_top_mb;
 mb_neigbour_params_t *ps_top_right_mb;
 mb_neigbour_params_t *ps_curmb;

    UWORD16 u2_mbx = ps_cur_mb_info->u2_mbx;
    UWORD32 ui_pred_width, ui_rec_width;
    WORD16 *pi2_y_coeff;
    UWORD8 u1_mbaff, u1_topmb, u1_mb_field_decoding_flag;
    UWORD32 u4_num_pmbair;
    UWORD16 ui2_luma_csbp = ps_cur_mb_info->u2_luma_csbp;
    UWORD8 *pu1_yleft, *pu1_ytop_left;
 /* Chroma variables*/
    UWORD8 *pu1_top_u;
    UWORD8 *pu1_uleft;
    UWORD8 *pu1_u_top_left;
 /* CHANGED CODE */
    UWORD8 *pu1_mb_cb_rei1_buffer, *pu1_mb_cr_rei1_buffer;
    UWORD32 u4_recwidth_cr;
 /* CHANGED CODE */
 tfr_ctxt_t *ps_frame_buf = ps_dec->ps_frame_buf_ip_recon;
    UWORD32 u4_luma_dc_only_csbp = 0;
    UWORD32 u4_luma_dc_only_cbp = 0;

    UWORD8 *pu1_prev_intra4x4_pred_mode_data = (UWORD8 *)ps_dec->pv_proc_tu_coeff_data; //Pointer to keep track of intra4x4_pred_mode data in pv_proc_tu_coeff_data buffer
    u1_mbaff = ps_dec->ps_cur_slice->u1_mbaff_frame_flag;
    u1_topmb = ps_cur_mb_info->u1_topmb;
    u4_num_pmbair = (u1_mb_num >> u1_mbaff);


 /*--------------------------------------------------------------------*/
 /* Find the current MB's mb params                                    */
 /*--------------------------------------------------------------------*/
    u1_mb_field_decoding_flag = ps_cur_mb_info->u1_mb_field_decodingflag;

    ps_curmb = ps_cur_mb_info->ps_curmb;
    ps_top_mb = ps_cur_mb_info->ps_top_mb;
    ps_left_mb = ps_cur_mb_info->ps_left_mb;
    ps_top_right_mb = ps_cur_mb_info->ps_top_right_mb;

 /*--------------------------------------------------------------------*/
 /* Check whether neighbouring MB is Inter MB and                      */
 /* constrained intra pred is 1.                                       */
 /*--------------------------------------------------------------------*/
    u2_use_left_mb_pack = (u2_use_left_mb << 8) + u2_use_left_mb;

 if(ps_dec->ps_cur_pps->u1_constrained_intra_pred_flag)
 {
        UWORD8 u1_left = (UWORD8)u2_use_left_mb;

        uc_useTopMB = uc_useTopMB
 && ((ps_top_mb->u1_mb_type != P_MB)
 && (ps_top_mb->u1_mb_type != B_MB));
        u2_use_left_mb = u2_use_left_mb
 && ((ps_left_mb->u1_mb_type != P_MB)
 && (ps_left_mb->u1_mb_type != B_MB));

        u2_use_left_mb_pack = (u2_use_left_mb << 8) + u2_use_left_mb;
 if(u1_mbaff)
 {
 if(u1_mb_field_decoding_flag ^ ps_left_mb->u1_mb_fld)
 {
                u1_left = u1_left
 && (((ps_left_mb + 1)->u1_mb_type != P_MB)
 && ((ps_left_mb + 1)->u1_mb_type
 != B_MB));
                u2_use_left_mb = u2_use_left_mb && u1_left;
 if(u1_mb_field_decoding_flag)
                    u2_use_left_mb_pack = (u1_left << 8)
 + (u2_use_left_mb_pack & 0xff);
 else
                    u2_use_left_mb_pack = (u2_use_left_mb << 8)
 + (u2_use_left_mb);
 }
 }
        u1_use_top_right_mb =
                        u1_use_top_right_mb
 && ((ps_top_right_mb->u1_mb_type != P_MB)
 && (ps_top_right_mb->u1_mb_type
 != B_MB));

        u1_use_top_left_mb =
                        u1_use_top_left_mb
 && ((ps_cur_mb_info->u1_topleft_mbtype != P_MB)
 && (ps_cur_mb_info->u1_topleft_mbtype
 != B_MB));
 }

 /*********************Common pointer calculations *************************/
 /* CHANGED CODE */
    pu1_luma_pred_buffer = ps_dec->pu1_y;
    pu1_luma_rec_buffer = ps_frame_buf->pu1_dest_y + (u4_num_pmbair << 4);
    pu1_mb_cb_rei1_buffer = ps_frame_buf->pu1_dest_u
 + (u4_num_pmbair << 3) * YUV420SP_FACTOR;
    pu1_mb_cr_rei1_buffer = ps_frame_buf->pu1_dest_v + (u4_num_pmbair << 3);
    ui_pred_width = MB_SIZE;
    ui_rec_width = ps_dec->u2_frm_wd_y << u1_mb_field_decoding_flag;
    u4_recwidth_cr = ps_dec->u2_frm_wd_uv << u1_mb_field_decoding_flag;
 /************* Current and top luma pointer *****************/

 if(u1_mbaff)
 {
 if(u1_topmb == 0)
 {
            pu1_luma_rec_buffer += (
                            u1_mb_field_decoding_flag ?
 (ui_rec_width >> 1) :
 (ui_rec_width << 4));
            pu1_mb_cb_rei1_buffer += (
                            u1_mb_field_decoding_flag ?
 (u4_recwidth_cr >> 1) :
 (u4_recwidth_cr << 3));
            pu1_mb_cr_rei1_buffer += (
                            u1_mb_field_decoding_flag ?
 (u4_recwidth_cr >> 1) :
 (u4_recwidth_cr << 3));
 }
 }

 /* CHANGED CODE */
 if(ps_dec->u4_use_intrapred_line_copy == 1)
 {
        puc_top = ps_dec->pu1_prev_y_intra_pred_line + (ps_cur_mb_info->u2_mbx << 4);
        pu1_top_u = ps_dec->pu1_prev_u_intra_pred_line
 + (ps_cur_mb_info->u2_mbx << 3) * YUV420SP_FACTOR;
 }
 else
 {
        puc_top = pu1_luma_rec_buffer - ui_rec_width;
        pu1_top_u = pu1_mb_cb_rei1_buffer - u4_recwidth_cr;
 }
 /* CHANGED CODE */

 /************* Left pointer *****************/
    pu1_yleft = pu1_luma_rec_buffer - 1;
    pu1_uleft = pu1_mb_cb_rei1_buffer - 1 * YUV420SP_FACTOR;

 /**************Top Left pointer calculation**********/
    pu1_ytop_left = puc_top - 1;
    pu1_u_top_left = pu1_top_u - 1 * YUV420SP_FACTOR;

 /* CHANGED CODE */
    PROFILE_DISABLE_INTRA_PRED()
 {
        pu1_prev_intra4x4_pred_mode_data = (UWORD8 *)ps_dec->pv_proc_tu_coeff_data;
 if(u1_mb_type == I_4x4_MB && ps_cur_mb_info->u1_tran_form8x8 == 0)
 {
            ps_dec->pv_proc_tu_coeff_data = (void *)((UWORD8 *)ps_dec->pv_proc_tu_coeff_data + 32);

 }
 else if (u1_mb_type == I_4x4_MB && ps_cur_mb_info->u1_tran_form8x8 == 1)
 {
            ps_dec->pv_proc_tu_coeff_data = (void *)((UWORD8 *)ps_dec->pv_proc_tu_coeff_data + 8);
 }
 }
 if(!ps_cur_mb_info->u1_tran_form8x8)
 {
        u4_luma_dc_only_csbp = ih264d_unpack_luma_coeff4x4_mb(ps_dec,
                                       ps_cur_mb_info,
 1);
 }
 else
 {
 if(!ps_dec->ps_cur_pps->u1_entropy_coding_mode)
 {
            u4_luma_dc_only_cbp = ih264d_unpack_luma_coeff4x4_mb(ps_dec,
                                           ps_cur_mb_info,
 1);
 }
 else
 {
            u4_luma_dc_only_cbp = ih264d_unpack_luma_coeff8x8_mb(ps_dec,
                                           ps_cur_mb_info);
 }
 }

    pi2_y_coeff = ps_dec->pi2_coeff_data;

 if(u1_mb_type != I_4x4_MB)
 {
        UWORD8 u1_intrapred_mode = MB_TYPE_TO_INTRA_16x16_MODE(u1_mb_type);
 /*--------------------------------------------------------------------*/
 /* 16x16 IntraPrediction                                              */
 /*--------------------------------------------------------------------*/
 {
            UWORD8 u1_packed_modes = (u1_top_available << 1)
 + u1_left_available;
            UWORD8 u1_err_code =
 (u1_intrapred_mode & 1) ?
                                            u1_intrapred_mode :
 (u1_intrapred_mode ^ 2);

 if((u1_err_code & u1_packed_modes) ^ u1_err_code)
 {
                u1_intrapred_mode = 0;
                ps_dec->i4_error_code = ERROR_INTRAPRED;
 }
 }
 {
            UWORD8 au1_ngbr_pels[33];
 /* Get neighbour pixels */
 /* left pels */
 if(u2_use_left_mb)
 {
                WORD32 i;
 for(i = 0; i < 16; i++)
                    au1_ngbr_pels[16 - 1 - i] = pu1_yleft[i * ui_rec_width];
 }
 else
 {
                memset(au1_ngbr_pels, 0, 16);
 }

 /* top left pels */
            au1_ngbr_pels[16] = *pu1_ytop_left;

 /* top pels */
 if(uc_useTopMB)
 {
                memcpy(au1_ngbr_pels + 16 + 1, puc_top, 16);
 }
 else
 {
                memset(au1_ngbr_pels + 16 + 1, 0, 16);
 }
            PROFILE_DISABLE_INTRA_PRED()
            ps_dec->apf_intra_pred_luma_16x16[u1_intrapred_mode](
                            au1_ngbr_pels, pu1_luma_rec_buffer, 1, ui_rec_width,
 ((uc_useTopMB << 2) | u2_use_left_mb));
 }
 {
            UWORD32 i;
            WORD16 ai2_tmp[16];
 for(i = 0; i < 16; i++)
 {
                WORD16 *pi2_level = pi2_y_coeff + (i << 4);
                UWORD8 *pu1_pred_sblk = pu1_luma_rec_buffer
 + ((i & 0x3) * BLK_SIZE)
 + (i >> 2) * (ui_rec_width << 2);
                PROFILE_DISABLE_IQ_IT_RECON()
 {
 if(CHECKBIT(ps_cur_mb_info->u2_luma_csbp, i))
 {
                        ps_dec->pf_iquant_itrans_recon_luma_4x4(
                                        pi2_level,
                                        pu1_pred_sblk,
                                        pu1_pred_sblk,
                                        ui_rec_width,
                                        ui_rec_width,
                                        gau2_ih264_iquant_scale_4x4[ps_cur_mb_info->u1_qp_rem6],
 (UWORD16 *)ps_dec->s_high_profile.i2_scalinglist4x4[0],
                                        ps_cur_mb_info->u1_qp_div6, ai2_tmp, 1,
                                        pi2_level);
 }
 else if((CHECKBIT(u4_luma_dc_only_csbp, i)) && pi2_level[0] != 0)
 {
                        ps_dec->pf_iquant_itrans_recon_luma_4x4_dc(
                                        pi2_level,
                                        pu1_pred_sblk,
                                        pu1_pred_sblk,
                                        ui_rec_width,
                                        ui_rec_width,
                                        gau2_ih264_iquant_scale_4x4[ps_cur_mb_info->u1_qp_rem6],
 (UWORD16 *)ps_dec->s_high_profile.i2_scalinglist4x4[0],
                                        ps_cur_mb_info->u1_qp_div6, ai2_tmp, 1,
                                        pi2_level);
 }
 }
 }
 }
 }
 else if(!ps_cur_mb_info->u1_tran_form8x8)
 {
        UWORD8 u1_is_left_sub_block, u1_is_top_sub_block = uc_useTopMB;
        UWORD8 u1_sub_blk_x, u1_sub_blk_y, u1_sub_mb_num;
        WORD8 i1_top_pred_mode;
        WORD8 i1_left_pred_mode;
        UWORD8 *pu1_top, *pu1_left, *pu1_top_left, *pu1_top_right;
        WORD8 *pi1_cur_pred_mode, *pi1_left_pred_mode, *pc_topPredMode;
        UWORD16 ui2_left_pred_buf_width = 0xffff;
        WORD8 i1_intra_pred;
        UWORD8 *pu1_prev_intra4x4_pred_mode_flag = pu1_prev_intra4x4_pred_mode_data;
        UWORD8 *pu1_rem_intra4x4_pred_mode = pu1_prev_intra4x4_pred_mode_data + 16;
        WORD16 *pi2_y_coeff1;
        UWORD8 u1_cur_sub_block;
        UWORD16 ui2_top_rt_mask;

 /*--------------------------------------------------------------------*/
 /* 4x4 IntraPrediction                                                */
 /*--------------------------------------------------------------------*/
 /* Calculation of Top Right subblock mask                             */
 /*                                                                    */
 /* (a) Set it to default mask                                         */
 /*     [It has 0 for sublocks which will never have top-right sub block] */
 /*                                                                    */
 /* (b) If top MB is not available                                     */
 /*      Clear the bits of the first row sub blocks                    */
 /*                                                                    */
 /* (c) Set/Clear bit for top-right sublock of MB                      */
 /*      [5 sub-block in decoding order] based on TOP RIGHT MB availablity */
 /*--------------------------------------------------------------------*/

        pu1_top = puc_top;

        ui2_top_rt_mask = (u1_use_top_right_mb << 3) | (0x5750);
 if(uc_useTopMB)
            ui2_top_rt_mask |= 0x7;

 /*Top Related initialisations*/


        pi1_cur_pred_mode = ps_cur_mb_info->ps_curmb->pi1_intrapredmodes;
        pc_topPredMode = ps_cur_mb_info->ps_top_mb->pi1_intrapredmodes;
 /*--------------------------------------
         if(u1_mbaff)
         {

         pi1_cur_pred_mode += (u2_mbx << 2);
         pc_topPredMode = pi1_cur_pred_mode + ps_cur_mb_info->i1_offset;
         pi1_cur_pred_mode += (u1_topmb) ? 0: 4;
         }*/

 if(u1_top_available)
 {
 if(ps_top_mb->u1_mb_type == I_4x4_MB)
 *(WORD32*)pi1_cur_pred_mode = *(WORD32*)pc_topPredMode;
 else
 *(WORD32*)pi1_cur_pred_mode =
 (uc_useTopMB) ? DC_DC_DC_DC : NOT_VALID;
 }
 else
 *(WORD32*)pi1_cur_pred_mode = NOT_VALID;
 /* CHANGED CODE */

 /* CHANGED CODE */

 /*Left Related initialisations*/
        pi1_left_pred_mode = ps_dec->pi1_left_pred_mode;
 if(!u1_mbaff)
 {

 if(u1_left_available)
 {

 if(ps_left_mb->u1_mb_type != I_4x4_MB)
 *(WORD32*)pi1_left_pred_mode =
 (u2_use_left_mb_pack) ?
                                    DC_DC_DC_DC :
                                                            NOT_VALID;

 }
 else
 {

 *(WORD32*)pi1_left_pred_mode = NOT_VALID;
 }

 }
 else
 {
            UWORD8 u1_curMbfld = ps_cur_mb_info->u1_mb_field_decodingflag;
            UWORD8 u1_leftMbfld = ps_left_mb->u1_mb_fld;

 if(u1_curMbfld ^ u1_leftMbfld)
 {

 if(u1_topmb
 | ((u1_topmb == 0)
 && ((ps_curmb - 1)->u1_mb_type
 != I_4x4_MB)))
 {
 if(u1_left_available)
 {
 if(ps_left_mb->u1_mb_type != I_4x4_MB)
 {
 if(CHECKBIT(u2_use_left_mb_pack,0) == 0)
 *(WORD32*)pi1_left_pred_mode = NOT_VALID;
 else
 *(WORD32*)pi1_left_pred_mode = DC_DC_DC_DC;
 }
 }
 else
 *(WORD32*)pi1_left_pred_mode = NOT_VALID;

 if(u1_curMbfld)
 {
 if(u1_left_available)
 {
 if((ps_left_mb + 1)->u1_mb_type != I_4x4_MB)
 {
 if(u2_use_left_mb_pack >> 8)
 *(WORD32*)(pi1_left_pred_mode + 4) =
                                                    DC_DC_DC_DC;
 else
 *(WORD32*)(pi1_left_pred_mode + 4) =
                                                    NOT_VALID;
 }
 }
 else
 *(WORD32*)(pi1_left_pred_mode + 4) = NOT_VALID;
                        pi1_left_pred_mode[1] = pi1_left_pred_mode[2];
                        pi1_left_pred_mode[2] = pi1_left_pred_mode[4];
                        pi1_left_pred_mode[3] = pi1_left_pred_mode[6];
 *(WORD32*)(pi1_left_pred_mode + 4) =
 *(WORD32*)pi1_left_pred_mode;
 }
 else
 {

                        pi1_left_pred_mode[7] = pi1_left_pred_mode[3];
                        pi1_left_pred_mode[6] = pi1_left_pred_mode[3];
                        pi1_left_pred_mode[5] = pi1_left_pred_mode[2];
                        pi1_left_pred_mode[4] = pi1_left_pred_mode[2];
                        pi1_left_pred_mode[3] = pi1_left_pred_mode[1];
                        pi1_left_pred_mode[2] = pi1_left_pred_mode[1];
                        pi1_left_pred_mode[1] = pi1_left_pred_mode[0];
 }
 }
                pi1_left_pred_mode += (u1_topmb) ? 0 : 4;
 }
 else
 {

                pi1_left_pred_mode += (u1_topmb) ? 0 : 4;
 if(u1_left_available)
 {

 if(ps_left_mb->u1_mb_type != I_4x4_MB)
 *(WORD32*)pi1_left_pred_mode =
 (u2_use_left_mb_pack) ?
                                        DC_DC_DC_DC :
                                                                NOT_VALID;
 }
 else
 *(WORD32*)pi1_left_pred_mode = NOT_VALID;
 }
 }
 /* One time pointer initialisations*/
        pi2_y_coeff1 = pi2_y_coeff;
        pu1_top_left = pu1_ytop_left;

 /* Scan the sub-blocks in Raster Scan Order */
 for(u1_sub_mb_num = 0; u1_sub_mb_num < 16; u1_sub_mb_num++)
 {
            UWORD8 au1_ngbr_pels[13];

            u1_sub_blk_x = u1_sub_mb_num & 0x3;
            u1_sub_blk_y = u1_sub_mb_num >> 2;
            i1_top_pred_mode = pi1_cur_pred_mode[u1_sub_blk_x];
            i1_left_pred_mode = pi1_left_pred_mode[u1_sub_blk_y];
            u1_use_top_right_mb = (!!CHECKBIT(ui2_top_rt_mask, u1_sub_mb_num));

 /*********** left subblock availability**********/
 if(u1_sub_blk_x)
                u1_is_left_sub_block = 1;
 else
                u1_is_left_sub_block =
 (u1_sub_blk_y < 2) ?
 (CHECKBIT(u2_use_left_mb_pack,
 0)) :
 (u2_use_left_mb_pack >> 8);

 /* CHANGED CODE */
 if(u1_sub_blk_y)
                u1_is_top_sub_block = 1;

 /* CHANGED CODE */
 /***************** Top *********************/
 if(ps_dec->u4_use_intrapred_line_copy == 1)
 {

 if(u1_sub_blk_y)
                    pu1_top = pu1_luma_rec_buffer - ui_rec_width;
 else
                    pu1_top = puc_top + (u1_sub_blk_x << 2);
 }
 else
 {
                pu1_top = pu1_luma_rec_buffer - ui_rec_width;
 }
 /***************** Top Right *********************/
            pu1_top_right = pu1_top + 4;
 /***************** Top Left *********************/
            pu1_top_left = pu1_top - 1;
 /***************** Left *********************/
            pu1_left = pu1_luma_rec_buffer - 1;
 /* CHANGED CODE */

 /*---------------------------------------------------------------*/
 /* Calculation of Intra prediction mode                          */
 /*---------------------------------------------------------------*/
            i1_intra_pred = ((i1_left_pred_mode < 0) | (i1_top_pred_mode < 0)) ?
                            DC : MIN(i1_left_pred_mode, i1_top_pred_mode);
 {
                UWORD8 u1_packed_modes = (u1_is_top_sub_block << 1)
 + u1_is_left_sub_block;
                UWORD8 *pu1_intra_err_codes =
 (UWORD8 *)gau1_ih264d_intra_pred_err_code;
                UWORD8 uc_b2b0 = ((u1_sub_mb_num & 4) >> 1) | (u1_sub_mb_num & 1);
                UWORD8 uc_b3b1 = ((u1_sub_mb_num & 8) >> 2)
 | ((u1_sub_mb_num & 2) >> 1);

                u1_cur_sub_block = (uc_b3b1 << 2) + uc_b2b0;
                PROFILE_DISABLE_INTRA_PRED()
 if(!pu1_prev_intra4x4_pred_mode_flag[u1_cur_sub_block])
 {
                    i1_intra_pred =
                                    pu1_rem_intra4x4_pred_mode[u1_cur_sub_block]

                                                     + (pu1_rem_intra4x4_pred_mode[u1_cur_sub_block]
                                                                     >= i1_intra_pred);
                 }
                 {
                     UWORD8 u1_err_code = pu1_intra_err_codes[i1_intra_pred];
 
 if((u1_err_code & u1_packed_modes) ^ u1_err_code)
 {
                        i1_intra_pred = 0;
                        ps_dec->i4_error_code = ERROR_INTRAPRED;
 }

 }
 }
 {
 /* Get neighbour pixels */
 /* left pels */
 if(u1_is_left_sub_block)
 {
                    WORD32 i;
 for(i = 0; i < 4; i++)
                        au1_ngbr_pels[4 - 1 - i] = pu1_left[i * ui_rec_width];
 }
 else
 {
                    memset(au1_ngbr_pels, 0, 4);
 }

 /* top left pels */
                au1_ngbr_pels[4] = *pu1_top_left;

 /* top pels */
 if(u1_is_top_sub_block)
 {
                    memcpy(au1_ngbr_pels + 4 + 1, pu1_top, 4);
 }
 else
 {
                    memset(au1_ngbr_pels + 4 + 1, 0, 4);
 }

 /* top right pels */
 if(u1_use_top_right_mb)
 {
                    memcpy(au1_ngbr_pels + 4 * 2 + 1, pu1_top_right, 4);
 }
 else if(u1_is_top_sub_block)
 {
                    memset(au1_ngbr_pels + 4 * 2 + 1, au1_ngbr_pels[4 * 2], 4);
 }
 }
            PROFILE_DISABLE_INTRA_PRED()
            ps_dec->apf_intra_pred_luma_4x4[i1_intra_pred](
                            au1_ngbr_pels, pu1_luma_rec_buffer, 1,
                            ui_rec_width,
 ((u1_is_top_sub_block << 2) | u1_is_left_sub_block));

 /* CHANGED CODE */
 if(CHECKBIT(ui2_luma_csbp, u1_sub_mb_num))
 {
                WORD16 ai2_tmp[16];
                PROFILE_DISABLE_IQ_IT_RECON()
 {
 if(CHECKBIT(u4_luma_dc_only_csbp, u1_sub_mb_num))
 {
                        ps_dec->pf_iquant_itrans_recon_luma_4x4_dc(
                                        pi2_y_coeff1,
                                        pu1_luma_rec_buffer,
                                        pu1_luma_rec_buffer,
                                        ui_rec_width,
                                        ui_rec_width,
                                        gau2_ih264_iquant_scale_4x4[ps_cur_mb_info->u1_qp_rem6],
 (UWORD16 *)ps_dec->s_high_profile.i2_scalinglist4x4[0],
                                        ps_cur_mb_info->u1_qp_div6, ai2_tmp, 0,
                                        NULL);
 }
 else
 {
                        ps_dec->pf_iquant_itrans_recon_luma_4x4(
                                        pi2_y_coeff1,
                                        pu1_luma_rec_buffer,
                                        pu1_luma_rec_buffer,
                                        ui_rec_width,
                                        ui_rec_width,
                                        gau2_ih264_iquant_scale_4x4[ps_cur_mb_info->u1_qp_rem6],
 (UWORD16 *)ps_dec->s_high_profile.i2_scalinglist4x4[0],
                                        ps_cur_mb_info->u1_qp_div6, ai2_tmp, 0,
                                        NULL);
 }
 }

 }

 /*---------------------------------------------------------------*/
 /* Update sub block number                                       */
 /*---------------------------------------------------------------*/
            pi2_y_coeff1 += 16;
            pu1_luma_rec_buffer +=
 (u1_sub_blk_x == 3) ? (ui_rec_width << 2) - 12 : 4;
            pu1_luma_pred_buffer +=
 (u1_sub_blk_x == 3) ? (ui_pred_width << 2) - 12 : 4;
 /* CHANGED CODE */
            pi1_cur_pred_mode[u1_sub_blk_x] = i1_intra_pred;
            pi1_left_pred_mode[u1_sub_blk_y] = i1_intra_pred;
 }
 }
 else if((u1_mb_type == I_4x4_MB) && (ps_cur_mb_info->u1_tran_form8x8 == 1))
 {
        UWORD8 u1_is_left_sub_block, u1_is_top_sub_block = uc_useTopMB;
        UWORD8 u1_sub_blk_x, u1_sub_blk_y, u1_sub_mb_num;
        WORD8 i1_top_pred_mode;
        WORD8 i1_left_pred_mode;
        UWORD8 *pu1_top, *pu1_left, *pu1_top_left;
        WORD8 *pi1_cur_pred_mode, *pi1_left_pred_mode, *pc_topPredMode;
        UWORD16 ui2_left_pred_buf_width = 0xffff;
        WORD8 i1_intra_pred;
        UWORD8 *pu1_prev_intra4x4_pred_mode_flag = pu1_prev_intra4x4_pred_mode_data;
        UWORD8 *pu1_rem_intra4x4_pred_mode = pu1_prev_intra4x4_pred_mode_data + 4;
        WORD16 *pi2_y_coeff1;
        UWORD16 ui2_top_rt_mask;
        UWORD32 u4_4x4_left_offset = 0;

 /*--------------------------------------------------------------------*/
 /* 8x8 IntraPrediction                                                */
 /*--------------------------------------------------------------------*/
 /* Calculation of Top Right subblock mask                             */
 /*                                                                    */
 /* (a) Set it to default mask                                         */
 /*  [It has 0 for sublocks which will never have top-right sub block] */
 /*                                                                    */
 /* (b) If top MB is not available                                     */
 /*      Clear the bits of the first row sub blocks                    */
 /*                                                                    */
 /* (c) Set/Clear bit for top-right sublock of MB                      */
 /*  [5 sub-block in decoding order] based on TOP RIGHT MB availablity */
 /*                                                                    */
 /* ui2_top_rt_mask: marks availibility of top right(neighbour)         */
 /* in the 8x8 Block ordering                                          */
 /*                                                                    */
 /*      tr0   tr1                                                     */
 /*   0    1   tr3                                                     */
 /*   2    3                                                           */
 /*                                                                    */
 /*  Top rights for 0 is in top MB                                     */
 /*  top right of 1 will be in top right MB                            */
 /*  top right of 3 in right MB and hence not available                */
 /*  This corresponds to ui2_top_rt_mask  having default value 0x4      */
 /*--------------------------------------------------------------------*/

        ui2_top_rt_mask = (u1_use_top_right_mb << 1) | (0x4);

 if(uc_useTopMB)
 {
            ui2_top_rt_mask |= 0x1;
 }

 /* Top Related initialisations */
        pi1_cur_pred_mode = ps_cur_mb_info->ps_curmb->pi1_intrapredmodes;
        pc_topPredMode = ps_cur_mb_info->ps_top_mb->pi1_intrapredmodes;
 /*
         if(u1_mbaff)
         {
         pi1_cur_pred_mode += (u2_mbx << 2);
         pc_topPredMode = pi1_cur_pred_mode + ps_cur_mb_info->i1_offset;
         pi1_cur_pred_mode += (u1_topmb) ? 0: 4;
         }
         */
 if(u1_top_available)
 {
 if(ps_top_mb->u1_mb_type == I_4x4_MB)
 {
 *(WORD32*)pi1_cur_pred_mode = *(WORD32*)pc_topPredMode;
 }
 else
 {
 *(WORD32*)pi1_cur_pred_mode =
 (uc_useTopMB) ? DC_DC_DC_DC : NOT_VALID;
 }
 }
 else
 {
 *(WORD32*)pi1_cur_pred_mode = NOT_VALID;
 }

        pu1_top = puc_top - 8;

 /*Left Related initialisations*/
        pi1_left_pred_mode = ps_dec->pi1_left_pred_mode;

 if(!u1_mbaff)
 {
 if(u1_left_available)
 {
 if(ps_left_mb->u1_mb_type != I_4x4_MB)
 {
 *(WORD32*)pi1_left_pred_mode =
 (u2_use_left_mb_pack) ?
                                    DC_DC_DC_DC :
                                                            NOT_VALID;
 }
 }
 else
 {
 *(WORD32*)pi1_left_pred_mode = NOT_VALID;
 }
 }
 else
 {
            UWORD8 u1_curMbfld = ps_cur_mb_info->u1_mb_field_decodingflag;

            UWORD8 u1_leftMbfld = ps_left_mb->u1_mb_fld;

 if((!u1_curMbfld) && (u1_leftMbfld))
 {
                u4_4x4_left_offset = 1;
 }

 if(u1_curMbfld ^ u1_leftMbfld)
 {

 if(u1_topmb
 | ((u1_topmb == 0)
 && ((ps_curmb - 1)->u1_mb_type
 != I_4x4_MB)))

 {
 if(u1_left_available)
 {
 if(ps_left_mb->u1_mb_type != I_4x4_MB)
 {
 if(CHECKBIT(u2_use_left_mb_pack,0) == 0)
 {
 *(WORD32*)pi1_left_pred_mode = NOT_VALID;
 }
 else
 {
 *(WORD32*)pi1_left_pred_mode = DC_DC_DC_DC;
 }
 }
 }
 else
 {
 *(WORD32*)pi1_left_pred_mode = NOT_VALID;
 }

 if(u1_curMbfld)
 {
 if(u1_left_available)
 {
 if((ps_left_mb + 1)->u1_mb_type != I_4x4_MB)
 {
 if(u2_use_left_mb_pack >> 8)
 {
 *(WORD32*)(pi1_left_pred_mode + 4) =
                                                    DC_DC_DC_DC;
 }
 else
 {
 *(WORD32*)(pi1_left_pred_mode + 4) =
                                                    NOT_VALID;
 }
 }
 }
 else
 {
 *(WORD32*)(pi1_left_pred_mode + 4) = NOT_VALID;
 }

                        pi1_left_pred_mode[1] = pi1_left_pred_mode[2];
                        pi1_left_pred_mode[2] = pi1_left_pred_mode[4];
                        pi1_left_pred_mode[3] = pi1_left_pred_mode[6];
 *(WORD32*)(pi1_left_pred_mode + 4) =
 *(WORD32*)pi1_left_pred_mode;
 }
 else
 {
                        pi1_left_pred_mode[7] = pi1_left_pred_mode[3];
                        pi1_left_pred_mode[6] = pi1_left_pred_mode[3];
                        pi1_left_pred_mode[5] = pi1_left_pred_mode[2];
                        pi1_left_pred_mode[4] = pi1_left_pred_mode[2];
                        pi1_left_pred_mode[3] = pi1_left_pred_mode[1];
                        pi1_left_pred_mode[2] = pi1_left_pred_mode[1];
                        pi1_left_pred_mode[1] = pi1_left_pred_mode[0];
 }
 }
                pi1_left_pred_mode += (u1_topmb) ? 0 : 4;
 }
 else
 {
                pi1_left_pred_mode += (u1_topmb) ? 0 : 4;

 if(u1_left_available)
 {
 if(ps_left_mb->u1_mb_type != I_4x4_MB)
 {
 *(WORD32*)pi1_left_pred_mode =
 (u2_use_left_mb_pack) ?
                                        DC_DC_DC_DC :
                                                                NOT_VALID;
 }
 }
 else
 {
 *(WORD32*)pi1_left_pred_mode = NOT_VALID;
 }
 }
 }

 /* One time pointer initialisations*/
        pi2_y_coeff1 = pi2_y_coeff;

 if(u1_use_top_left_mb)
 {
            pu1_top_left = pu1_ytop_left;
 }
 else
 {
            pu1_top_left = NULL;
 }

 /* Scan the sub-blocks in Raster Scan Order */
 for(u1_sub_mb_num = 0; u1_sub_mb_num < 4; u1_sub_mb_num++)
 {
            u1_sub_blk_x = (u1_sub_mb_num & 0x1);
            u1_sub_blk_y = (u1_sub_mb_num >> 1);
            i1_top_pred_mode = pi1_cur_pred_mode[u1_sub_blk_x << 1];
            i1_left_pred_mode = pi1_left_pred_mode[u1_sub_blk_y << 1];

 if(2 == u1_sub_mb_num)
 {
                i1_left_pred_mode = pi1_left_pred_mode[(u1_sub_blk_y << 1)
 + u4_4x4_left_offset];
 }

            u1_use_top_right_mb = (!!CHECKBIT(ui2_top_rt_mask, u1_sub_mb_num));

 /*********** left subblock availability**********/
 if(u1_sub_blk_x)
 {
                u1_is_left_sub_block = 1;
 }
 else
 {
                u1_is_left_sub_block =
 (u1_sub_blk_y < 1) ?
 (CHECKBIT(u2_use_left_mb_pack,
 0)) :
 (u2_use_left_mb_pack >> 8);
 }

 /***************** Top *********************/
 if(u1_sub_blk_y)
 {
                u1_is_top_sub_block = 1;
                pu1_top = /*pu1_luma_pred_buffer*/pu1_luma_rec_buffer - ui_rec_width;
 }
 else
 {
                pu1_top += 8;
 }

 /***************** Left *********************/
 if((u1_sub_blk_x) | (u4_num_pmbair != 0))
 {
                pu1_left = /*pu1_luma_pred_buffer*/pu1_luma_rec_buffer - 1;
                ui2_left_pred_buf_width = ui_rec_width;
 }
 else
 {
                pu1_left = pu1_yleft;
                pu1_yleft += (ui_rec_width << 3);
                ui2_left_pred_buf_width = ui_rec_width;
 }

 /***************** Top Left *********************/
 if(u1_sub_mb_num)
 {
                pu1_top_left = (u1_sub_blk_x) ?
                                pu1_top - 1 : pu1_left - ui_rec_width;

 if((u1_sub_blk_x && (!u1_is_top_sub_block))
 || ((!u1_sub_blk_x) && (!u1_is_left_sub_block)))
 {
                    pu1_top_left = NULL;
 }
 }

 /*---------------------------------------------------------------*/
 /* Calculation of Intra prediction mode                          */
 /*---------------------------------------------------------------*/
            i1_intra_pred = ((i1_left_pred_mode < 0) | (i1_top_pred_mode < 0)) ?
                            DC : MIN(i1_left_pred_mode, i1_top_pred_mode);
 {
                UWORD8 u1_packed_modes = (u1_is_top_sub_block << 1)
 + u1_is_left_sub_block;
                UWORD8 *pu1_intra_err_codes =
 (UWORD8 *)gau1_ih264d_intra_pred_err_code;

 /********************************************************************/
 /* Same intra4x4_pred_mode array is filled with intra4x4_pred_mode  */
 /* for a MB with 8x8 intrapredicition                               */
 /********************************************************************/
                PROFILE_DISABLE_INTRA_PRED()
 if(!pu1_prev_intra4x4_pred_mode_flag[u1_sub_mb_num])
 {
                    i1_intra_pred = pu1_rem_intra4x4_pred_mode[u1_sub_mb_num]

                                     + (pu1_rem_intra4x4_pred_mode[u1_sub_mb_num]
                                                     >= i1_intra_pred);
                 }
                 {
                     UWORD8 u1_err_code = pu1_intra_err_codes[i1_intra_pred];
 
 if((u1_err_code & u1_packed_modes) ^ u1_err_code)
 {
                        i1_intra_pred = 0;
                        ps_dec->i4_error_code = ERROR_INTRAPRED;
 }
 }
 }

 {
                UWORD8 au1_ngbr_pels[25];
                WORD32 ngbr_avail;
                ngbr_avail = u1_is_left_sub_block << 0;
                ngbr_avail |= u1_is_top_sub_block << 2;

 if(pu1_top_left)
                    ngbr_avail |= 1 << 1;

                ngbr_avail |= u1_use_top_right_mb << 3;
                PROFILE_DISABLE_INTRA_PRED()
 {
                    ps_dec->pf_intra_pred_ref_filtering(pu1_left, pu1_top_left,
                                                        pu1_top, au1_ngbr_pels,
                                                        ui2_left_pred_buf_width,
                                                        ngbr_avail);

                    ps_dec->apf_intra_pred_luma_8x8[i1_intra_pred](
                                    au1_ngbr_pels, pu1_luma_rec_buffer, 1,
                                    ui_rec_width,
 ((u1_is_top_sub_block << 2) | u1_is_left_sub_block));
 }
 }

 /* Inverse Transform and Reconstruction */
 if(CHECKBIT(ps_cur_mb_info->u1_cbp, u1_sub_mb_num))
 {
                WORD16 *pi2_scale_matrix_ptr;
                WORD16 ai2_tmp[64];

                pi2_scale_matrix_ptr =
                                ps_dec->s_high_profile.i2_scalinglist8x8[0];
                PROFILE_DISABLE_IQ_IT_RECON()
 {
 if(CHECKBIT(u4_luma_dc_only_cbp, u1_sub_mb_num))
 {
                        ps_dec->pf_iquant_itrans_recon_luma_8x8_dc(
                                        pi2_y_coeff1,
                                        pu1_luma_rec_buffer,
                                        pu1_luma_rec_buffer,
                                        ui_rec_width,
                                        ui_rec_width,
                                        gau1_ih264d_dequant8x8_cavlc[ps_cur_mb_info->u1_qp_rem6],
 (UWORD16 *)pi2_scale_matrix_ptr,
                                        ps_cur_mb_info->u1_qp_div6, ai2_tmp, 0,
                                        NULL);
 }
 else
 {
                        ps_dec->pf_iquant_itrans_recon_luma_8x8(
                                        pi2_y_coeff1,
                                        pu1_luma_rec_buffer,
                                        pu1_luma_rec_buffer,
                                        ui_rec_width,
                                        ui_rec_width,
                                        gau1_ih264d_dequant8x8_cavlc[ps_cur_mb_info->u1_qp_rem6],
 (UWORD16 *)pi2_scale_matrix_ptr,
                                        ps_cur_mb_info->u1_qp_div6, ai2_tmp, 0,
                                        NULL);
 }
 }

 }

 /*---------------------------------------------------------------*/
 /* Update sub block number                                       */
 /*---------------------------------------------------------------*/
            pi2_y_coeff1 += 64;

            pu1_luma_rec_buffer +=
 (u1_sub_blk_x == 1) ?
 (ui_rec_width << 3) - (8 * 1) : 8;

 /*---------------------------------------------------------------*/
 /* Pred mode filled in terms of 4x4 block so replicated in 2     */
 /* locations.                                                    */
 /*---------------------------------------------------------------*/
            pi1_cur_pred_mode[u1_sub_blk_x << 1] = i1_intra_pred;
            pi1_cur_pred_mode[(u1_sub_blk_x << 1) + 1] = i1_intra_pred;
            pi1_left_pred_mode[u1_sub_blk_y << 1] = i1_intra_pred;
            pi1_left_pred_mode[(u1_sub_blk_y << 1) + 1] = i1_intra_pred;
 }
 }
 /* Decode Chroma Block */
    ih264d_unpack_chroma_coeff4x4_mb(ps_dec,
                                     ps_cur_mb_info);
 /*--------------------------------------------------------------------*/
 /* Chroma Blocks decoding                                             */
 /*--------------------------------------------------------------------*/
 {
        UWORD8 u1_intra_chrom_pred_mode;
        UWORD8 u1_chroma_cbp = (UWORD8)(ps_cur_mb_info->u1_cbp >> 4);

 /*--------------------------------------------------------------------*/
 /* Perform Chroma intra prediction                                    */
 /*--------------------------------------------------------------------*/

        u1_intra_chrom_pred_mode = CHROMA_TO_LUMA_INTRA_MODE(
                        ps_cur_mb_info->u1_chroma_pred_mode);

 {
            UWORD8 u1_packed_modes = (u1_top_available << 1)
 + u1_left_available;
            UWORD8 u1_err_code =
 (u1_intra_chrom_pred_mode & 1) ?
                                            u1_intra_chrom_pred_mode :
 (u1_intra_chrom_pred_mode ^ 2);
 if((u1_err_code & u1_packed_modes) ^ u1_err_code)
 {
                u1_intra_chrom_pred_mode = 0;
                ps_dec->i4_error_code = ERROR_INTRAPRED;
 }
 }

 /* CHANGED CODE */
 if(u1_chroma_cbp != CBPC_ALLZERO)
 {
            UWORD16 u2_chroma_csbp =
 (u1_chroma_cbp == CBPC_ACZERO) ?
 0 : ps_cur_mb_info->u2_chroma_csbp;
            UWORD32 u4_scale_u;
            UWORD32 u4_scale_v;

 {
                UWORD16 au2_ngbr_pels[33];
                UWORD8 *pu1_ngbr_pels = (UWORD8 *)au2_ngbr_pels;
                UWORD16 *pu2_left_uv;
                UWORD16 *pu2_topleft_uv;
                WORD32 use_left1 = (u2_use_left_mb_pack & 0x0ff);
                WORD32 use_left2 = (u2_use_left_mb_pack & 0xff00) >> 8;

                pu2_left_uv = (UWORD16 *)pu1_uleft;
                pu2_topleft_uv = (UWORD16 *)pu1_u_top_left;
 /* Get neighbour pixels */
 /* left pels */
 if(u2_use_left_mb_pack)
 {
                    WORD32 i;
 if(use_left1)
 {
 for(i = 0; i < 4; i++)
                            au2_ngbr_pels[8 - 1 - i] = pu2_left_uv[i
 * u4_recwidth_cr / YUV420SP_FACTOR];
 }
 else
 {
                        memset(au2_ngbr_pels + 4, 0, 4 * sizeof(UWORD16));
 }

 if(use_left2)
 {
 for(i = 4; i < 8; i++)
                            au2_ngbr_pels[8 - 1 - i] = pu2_left_uv[i
 * u4_recwidth_cr / YUV420SP_FACTOR];
 }
 else
 {
                        memset(au2_ngbr_pels, 0, 4 * sizeof(UWORD16));
 }
 }
 else
 {
                    memset(au2_ngbr_pels, 0, 8 * sizeof(UWORD16));
 }

 /* top left pels */
                au2_ngbr_pels[8] = *pu2_topleft_uv;

 /* top pels */
 if(uc_useTopMB)
 {
                    memcpy(au2_ngbr_pels + 8 + 1, pu1_top_u,
 8 * sizeof(UWORD16));
 }
 else
 {
                    memset(au2_ngbr_pels + 8 + 1, 0, 8 * sizeof(UWORD16));
 }

                PROFILE_DISABLE_INTRA_PRED()
                ps_dec->apf_intra_pred_chroma[u1_intra_chrom_pred_mode](
                                pu1_ngbr_pels,
                                pu1_mb_cb_rei1_buffer,
 1,
                                u4_recwidth_cr,
 ((uc_useTopMB << 2) | (use_left2 << 4)
 | use_left1));
 }
            u4_scale_u = ps_cur_mb_info->u1_qpc_div6;
            u4_scale_v = ps_cur_mb_info->u1_qpcr_div6;
            pi2_y_coeff = ps_dec->pi2_coeff_data;

 {
                UWORD32 i;
                WORD16 ai2_tmp[16];
 for(i = 0; i < 4; i++)
 {
                    WORD16 *pi2_level = pi2_y_coeff + (i << 4);
                    UWORD8 *pu1_pred_sblk = pu1_mb_cb_rei1_buffer
 + ((i & 0x1) * BLK_SIZE * YUV420SP_FACTOR)
 + (i >> 1) * (u4_recwidth_cr << 2);
                    PROFILE_DISABLE_IQ_IT_RECON()
 {
 if(CHECKBIT(u2_chroma_csbp, i))
 {
                            ps_dec->pf_iquant_itrans_recon_chroma_4x4(
                                            pi2_level,
                                            pu1_pred_sblk,
                                            pu1_pred_sblk,
                                            u4_recwidth_cr,
                                            u4_recwidth_cr,
                                            gau2_ih264_iquant_scale_4x4[ps_cur_mb_info->u1_qpc_rem6],
 (UWORD16 *)ps_dec->s_high_profile.i2_scalinglist4x4[1],
                                            u4_scale_u, ai2_tmp, pi2_level);
 }
 else if(pi2_level[0] != 0)
 {
                            ps_dec->pf_iquant_itrans_recon_chroma_4x4_dc(
                                            pi2_level,
                                            pu1_pred_sblk,
                                            pu1_pred_sblk,
                                            u4_recwidth_cr,
                                            u4_recwidth_cr,
                                            gau2_ih264_iquant_scale_4x4[ps_cur_mb_info->u1_qpc_rem6],
 (UWORD16 *)ps_dec->s_high_profile.i2_scalinglist4x4[1],
                                            u4_scale_u, ai2_tmp, pi2_level);
 }
 }

 }
 }

            pi2_y_coeff += MB_CHROM_SIZE;
            u2_chroma_csbp = u2_chroma_csbp >> 4;
 {
                UWORD32 i;
                WORD16 ai2_tmp[16];
 for(i = 0; i < 4; i++)
 {
                    WORD16 *pi2_level = pi2_y_coeff + (i << 4);
                    UWORD8 *pu1_pred_sblk = pu1_mb_cb_rei1_buffer + 1
 + ((i & 0x1) * BLK_SIZE * YUV420SP_FACTOR)
 + (i >> 1) * (u4_recwidth_cr << 2);
                    PROFILE_DISABLE_IQ_IT_RECON()
 {
 if(CHECKBIT(u2_chroma_csbp, i))
 {
                            ps_dec->pf_iquant_itrans_recon_chroma_4x4(
                                            pi2_level,
                                            pu1_pred_sblk,
                                            pu1_pred_sblk,
                                            u4_recwidth_cr,
                                            u4_recwidth_cr,
                                            gau2_ih264_iquant_scale_4x4[ps_cur_mb_info->u1_qpcr_rem6],
 (UWORD16 *)ps_dec->s_high_profile.i2_scalinglist4x4[2],
                                            u4_scale_v, ai2_tmp, pi2_level);
 }
 else if(pi2_level[0] != 0)
 {
                            ps_dec->pf_iquant_itrans_recon_chroma_4x4_dc(
                                            pi2_level,
                                            pu1_pred_sblk,
                                            pu1_pred_sblk,
                                            u4_recwidth_cr,
                                            u4_recwidth_cr,
                                            gau2_ih264_iquant_scale_4x4[ps_cur_mb_info->u1_qpcr_rem6],
 (UWORD16 *)ps_dec->s_high_profile.i2_scalinglist4x4[2],
                                            u4_scale_v, ai2_tmp, pi2_level);
 }
 }
 }
 }

 }
 else
 {
 /* If no inverse transform is needed, pass recon buffer pointer */
 /* to Intraprediction module instead of pred buffer pointer     */
 {
                UWORD16 au2_ngbr_pels[33];
                UWORD8 *pu1_ngbr_pels = (UWORD8 *)au2_ngbr_pels;
                UWORD16 *pu2_left_uv;
                UWORD16 *pu2_topleft_uv;
                WORD32 use_left1 = (u2_use_left_mb_pack & 0x0ff);
                WORD32 use_left2 = (u2_use_left_mb_pack & 0xff00) >> 8;

                pu2_topleft_uv = (UWORD16 *)pu1_u_top_left;
                pu2_left_uv = (UWORD16 *)pu1_uleft;

 /* Get neighbour pixels */
 /* left pels */
 if(u2_use_left_mb_pack)
 {
                    WORD32 i;
 if(use_left1)
 {
 for(i = 0; i < 4; i++)
                            au2_ngbr_pels[8 - 1 - i] = pu2_left_uv[i
 * u4_recwidth_cr / YUV420SP_FACTOR];
 }
 else
 {
                        memset(au2_ngbr_pels + 4, 0, 4 * sizeof(UWORD16));
 }

 if(use_left2)
 {
 for(i = 4; i < 8; i++)
                            au2_ngbr_pels[8 - 1 - i] = pu2_left_uv[i
 * u4_recwidth_cr / YUV420SP_FACTOR];
 }
 else
 {
                        memset(au2_ngbr_pels, 0, 4 * sizeof(UWORD16));
 }

 }
 else
 {
                    memset(au2_ngbr_pels, 0, 8 * sizeof(UWORD16));
 }

 /* top left pels */
                au2_ngbr_pels[8] = *pu2_topleft_uv;

 /* top pels */
 if(uc_useTopMB)
 {
                    memcpy(au2_ngbr_pels + 8 + 1, pu1_top_u,
 8 * sizeof(UWORD16));
 }
 else
 {
                    memset(au2_ngbr_pels + 8 + 1, 0, 8 * sizeof(UWORD16));
 }

                PROFILE_DISABLE_INTRA_PRED()
                ps_dec->apf_intra_pred_chroma[u1_intra_chrom_pred_mode](
                                pu1_ngbr_pels,
                                pu1_mb_cb_rei1_buffer,
 1,
                                u4_recwidth_cr,
 ((uc_useTopMB << 2) | (use_left2 << 4)
 | use_left1));
 }

 }

 }
 return OK;
}