IMPEG2D_ERROR_CODES_T impeg2d_dec_p_b_slice(dec_state_t *ps_dec)
{
    WORD16 *pi2_vld_out;
    UWORD32 i;
 yuv_buf_t *ps_cur_frm_buf      = &ps_dec->s_cur_frm_buf;

    UWORD32 u4_frm_offset          = 0;
 const dec_mb_params_t *ps_dec_mb_params;
    IMPEG2D_ERROR_CODES_T e_error   = (IMPEG2D_ERROR_CODES_T)IVD_ERROR_NONE;

    pi2_vld_out = ps_dec->ai2_vld_buf;
    memset(ps_dec->ai2_pred_mv,0,sizeof(ps_dec->ai2_pred_mv));

    ps_dec->u2_prev_intra_mb    = 0;
    ps_dec->u2_first_mb       = 1;

    ps_dec->u2_picture_width = ps_dec->u2_frame_width;

 if(ps_dec->u2_picture_structure != FRAME_PICTURE)
 {
        ps_dec->u2_picture_width <<= 1;
 if(ps_dec->u2_picture_structure == BOTTOM_FIELD)
 {
            u4_frm_offset = ps_dec->u2_frame_width;
 }
 }

 do
 {
        UWORD32 u4_x_offset, u4_y_offset;
        WORD32 ret;


        UWORD32 u4_x_dst_offset = 0;
        UWORD32 u4_y_dst_offset = 0;
        UWORD8  *pu1_out_p;
        UWORD8  *pu1_pred;
        WORD32 u4_pred_strd;

        IMPEG2D_TRACE_MB_START(ps_dec->u2_mb_x, ps_dec->u2_mb_y);

 if(ps_dec->e_pic_type == B_PIC)
            ret = impeg2d_dec_pnb_mb_params(ps_dec);
 else
            ret = impeg2d_dec_p_mb_params(ps_dec);

 
         if(ret)
             return IMPEG2D_MB_TEX_DECODE_ERR;

        if(0 >= ps_dec->u2_num_mbs_left)
        {
            break;
        }

         IMPEG2D_TRACE_MB_START(ps_dec->u2_mb_x, ps_dec->u2_mb_y);
 
         u4_x_dst_offset = u4_frm_offset + (ps_dec->u2_mb_x << 4);
        u4_y_dst_offset = (ps_dec->u2_mb_y << 4) * ps_dec->u2_picture_width;
        pu1_out_p = ps_cur_frm_buf->pu1_y + u4_x_dst_offset + u4_y_dst_offset;
 if(ps_dec->u2_prev_intra_mb == 0)
 {
            UWORD32 offset_x, offset_y, stride;
            UWORD16 index = (ps_dec->u2_motion_type);
 /*only for non intra mb's*/
 if(ps_dec->e_mb_pred == BIDIRECT)
 {
                ps_dec_mb_params = &ps_dec->ps_func_bi_direct[index];
 }
 else
 {
                ps_dec_mb_params = &ps_dec->ps_func_forw_or_back[index];
 }

            stride = ps_dec->u2_picture_width;

            offset_x = u4_frm_offset + (ps_dec->u2_mb_x << 4);

            offset_y = (ps_dec->u2_mb_y << 4);

            ps_dec->s_dest_buf.pu1_y = ps_cur_frm_buf->pu1_y + offset_y * stride + offset_x;

            stride = stride >> 1;

            ps_dec->s_dest_buf.pu1_u = ps_cur_frm_buf->pu1_u + (offset_y >> 1) * stride
 + (offset_x >> 1);

            ps_dec->s_dest_buf.pu1_v = ps_cur_frm_buf->pu1_v + (offset_y >> 1) * stride
 + (offset_x >> 1);

            PROFILE_DISABLE_MC_IF0
            ps_dec_mb_params->pf_mc(ps_dec);

 }
 for(i = 0; i < NUM_LUMA_BLKS; ++i)
 {
 if((ps_dec->u2_cbp & (1 << (BLOCKS_IN_MB - 1 - i))) != 0)
 {
                e_error = ps_dec->pf_vld_inv_quant(ps_dec, pi2_vld_out, ps_dec->pu1_inv_scan_matrix,
                              ps_dec->u2_prev_intra_mb, Y_LUMA, 0);
 if ((IMPEG2D_ERROR_CODES_T)IVD_ERROR_NONE != e_error)
 {
 return e_error;
 }

                u4_x_offset = gai2_impeg2_blk_x_off[i];

 if(ps_dec->u2_field_dct == 0)
                    u4_y_offset = gai2_impeg2_blk_y_off_frm[i] ;
 else
                    u4_y_offset = gai2_impeg2_blk_y_off_fld[i] ;





                IMPEG2D_IDCT_INP_STATISTICS(pi2_vld_out, ps_dec->u4_non_zero_cols, ps_dec->u4_non_zero_rows);

                PROFILE_DISABLE_IDCT_IF0
 {
                    WORD32 idx;
 if(1 == (ps_dec->u4_non_zero_cols | ps_dec->u4_non_zero_rows))
                        idx = 0;
 else
                        idx = 1;

 if(0 == ps_dec->u2_prev_intra_mb)
 {
                        pu1_pred = pu1_out_p + u4_y_offset * ps_dec->u2_picture_width + u4_x_offset;
                        u4_pred_strd = ps_dec->u2_picture_width << ps_dec->u2_field_dct;
 }
 else
 {
                        pu1_pred = (UWORD8 *)gau1_impeg2_zerobuf;
                        u4_pred_strd = 8;
 }

                    ps_dec->pf_idct_recon[idx * 2 + ps_dec->i4_last_value_one](pi2_vld_out,
                                                            ps_dec->ai2_idct_stg1,
                                                            pu1_pred,
                                                            pu1_out_p + u4_y_offset * ps_dec->u2_picture_width + u4_x_offset,
 8,
                                                            u4_pred_strd,
                                                            ps_dec->u2_picture_width << ps_dec->u2_field_dct,
 ~ps_dec->u4_non_zero_cols, ~ps_dec->u4_non_zero_rows);
 }
 }

 }

 /* For U and V blocks, divide the x and y offsets by 2. */
        u4_x_dst_offset >>= 1;
        u4_y_dst_offset >>= 2;


 /* In case of chrominance blocks the DCT will be frame DCT */
 /* i = 0, U component and i = 1 is V componet */
 if((ps_dec->u2_cbp & 0x02) != 0)
 {
            pu1_out_p = ps_cur_frm_buf->pu1_u + u4_x_dst_offset + u4_y_dst_offset;
            e_error = ps_dec->pf_vld_inv_quant(ps_dec, pi2_vld_out, ps_dec->pu1_inv_scan_matrix,
                          ps_dec->u2_prev_intra_mb, U_CHROMA, 0);
 if ((IMPEG2D_ERROR_CODES_T)IVD_ERROR_NONE != e_error)
 {
 return e_error;
 }


            IMPEG2D_IDCT_INP_STATISTICS(pi2_vld_out, ps_dec->u4_non_zero_cols, ps_dec->u4_non_zero_rows);

            PROFILE_DISABLE_IDCT_IF0
 {
                WORD32 idx;
 if(1 == (ps_dec->u4_non_zero_cols | ps_dec->u4_non_zero_rows))
                    idx = 0;
 else
                    idx = 1;

 if(0 == ps_dec->u2_prev_intra_mb)
 {
                    pu1_pred = pu1_out_p;
                    u4_pred_strd = ps_dec->u2_picture_width >> 1;
 }
 else
 {
                    pu1_pred = (UWORD8 *)gau1_impeg2_zerobuf;
                    u4_pred_strd = 8;
 }

                ps_dec->pf_idct_recon[idx * 2 + ps_dec->i4_last_value_one](pi2_vld_out,
                                                        ps_dec->ai2_idct_stg1,
                                                        pu1_pred,
                                                        pu1_out_p,
 8,
                                                        u4_pred_strd,
                                                        ps_dec->u2_picture_width >> 1,
 ~ps_dec->u4_non_zero_cols, ~ps_dec->u4_non_zero_rows);

 }

 }


 if((ps_dec->u2_cbp & 0x01) != 0)
 {
            pu1_out_p = ps_cur_frm_buf->pu1_v + u4_x_dst_offset + u4_y_dst_offset;
            e_error = ps_dec->pf_vld_inv_quant(ps_dec, pi2_vld_out, ps_dec->pu1_inv_scan_matrix,
                          ps_dec->u2_prev_intra_mb, V_CHROMA, 0);
 if ((IMPEG2D_ERROR_CODES_T)IVD_ERROR_NONE != e_error)
 {
 return e_error;
 }


            IMPEG2D_IDCT_INP_STATISTICS(pi2_vld_out, ps_dec->u4_non_zero_cols, ps_dec->u4_non_zero_rows);

            PROFILE_DISABLE_IDCT_IF0
 {
                WORD32 idx;
 if(1 == (ps_dec->u4_non_zero_cols | ps_dec->u4_non_zero_rows))
                    idx = 0;
 else
                    idx = 1;
 if(0 == ps_dec->u2_prev_intra_mb)
 {
                    pu1_pred = pu1_out_p;
                    u4_pred_strd = ps_dec->u2_picture_width >> 1;
 }
 else
 {
                    pu1_pred = (UWORD8 *)gau1_impeg2_zerobuf;
                    u4_pred_strd = 8;
 }

                ps_dec->pf_idct_recon[idx * 2 + ps_dec->i4_last_value_one](pi2_vld_out,
                                                        ps_dec->ai2_idct_stg1,
                                                        pu1_pred,
                                                        pu1_out_p,
 8,
                                                        u4_pred_strd,
                                                        ps_dec->u2_picture_width >> 1,
 ~ps_dec->u4_non_zero_cols, ~ps_dec->u4_non_zero_rows);

 }
 }

        ps_dec->u2_num_mbs_left--;
        ps_dec->u2_first_mb = 0;
        ps_dec->u2_mb_x++;

 if(ps_dec->s_bit_stream.u4_offset > ps_dec->s_bit_stream.u4_max_offset)
 {
 return IMPEG2D_BITSTREAM_BUFF_EXCEEDED_ERR;
 }
 else if (ps_dec->u2_mb_x == ps_dec->u2_num_horiz_mb)
 {
            ps_dec->u2_mb_x = 0;
            ps_dec->u2_mb_y++;

 }
 }
 while(ps_dec->u2_num_mbs_left != 0 && impeg2d_bit_stream_nxt(&ps_dec->s_bit_stream,23) != 0x0);
 return e_error;
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.