source: svn/trunk/newcon3bcm2_21bu/dta/src/dvb/dvb_tdt.c @ 31

/***************************************************************************
 *     Copyright (c) 2011, Broadcom Corporation
 *     All Rights Reserved
 *     Confidential Property of Broadcom Corporation
 *
 *  THIS SOFTWARE MAY ONLY BE USED SUBJECT TO AN EXECUTED SOFTWARE LICENSE
 *  AGREEMENT  BETWEEN THE USER AND BROADCOM.  YOU HAVE NO RIGHT TO USE OR
 *  EXPLOIT THIS MATERIAL EXCEPT SUBJECT TO THE TERMS OF SUCH AN AGREEMENT.
 *
 * $brcm_Workfile:  $
 * $brcm_Revision:  $
 * $brcm_Date: $
 *
 * Module Description:
 *
 * Revision History:
 *
 * $brcm_Log:  $
 *
 ****************************************************************************/

#include "bstd.h"
#include "bkni.h"
#include "dvb_parser.h"

static uint32_t tdt_cur_time;
static tot_map_t tot_map;

BDBG_MODULE(dvb_tdt);

void dvb_tdt_init(void)
{
        tdt_cur_time = 0;
        BKNI_Memset(&tot_map, 0, sizeof(tot_map_t));
}

int dvb_tdt_parse(const uint8_t *tdt_buf, size_t *psize)
{
        uint16_t section_len, desc_len, idx;
        uint8_t tid;
        struct bit_state_t bs;
        
        BDBG_ASSERT((tdt_buf&&psize));
        BDBG_MSG(("%s: enter (%x)", __FUNCTION__, tid));

        bs.bindex = 0;
        bs.data = (unsigned char *)tdt_buf;
        
        tid = get_bits(8, &bs);
        if ((tid != DVB_TID_TIME_DATE) && (tid != DVB_TID_TIME_OFFSET)) {
                BDBG_WRN(("%s: only time_date and offset are processing (0x%x)", __FUNCTION__, tid));
                return 0;
        }

        get_bits(4, &bs); /* skip section_syntax_indicator, reserved */
        section_len = get_bits(12, &bs);
        if (*psize < (section_len+3)) {
                BDBG_WRN(("%s: invalid TDT/TOT table", __FUNCTION__));
                return 0;
        }

        idx = bs.bindex/8;
        tdt_cur_time = MJD_TO_TIME(tdt_buf[idx], tdt_buf[idx+1]) + 
                BCD_TO_SEC(tdt_buf[idx+2], tdt_buf[idx+3], tdt_buf[idx+4]);

        bs.bindex += 40;
        
        if ( tid == DVB_TID_TIME_OFFSET ) {
                get_bits(4, &bs); /* skip reserved */
                desc_len = get_bits(12, &bs);
                /* TODO: how to apply time_offset value into system time */
                dvb_parse_descriptors((uint8_t *)&tdt_buf[bs.bindex/8], desc_len, DVB_TID_TIME_OFFSET, (void *)&tot_map);
        }

        if (tid == DVB_TID_TIME_DATE) 
                return 1;
        else {
                return 0;
        }
}

uint32_t dvb_get_cur_time(void)
{
        return tdt_cur_time;
}

/*
 * convert MJD (modified julian date) to Y/M/D format
 * convert is applicable between the inclusive dates 1900 March 1 to 2100 February 28
 *
 * year: from 1900
 */
static void dvb_mjd_to_ymd(uint16_t mjd, int *year, int *month, int *day)
{
    uint32_t y_delta, m_delta, k;

    y_delta = (int)((double)(mjd-15078.2)/(double)365.25);
    m_delta = (int)((double)((double)mjd-14956.1-(int)((double)y_delta*365.25))/30.6001);
    *day = mjd-14956 - (int)((double)y_delta*365.25) - (int)((double)m_delta*30.6001);
    if (m_delta == 14 || m_delta == 15) k = 1;
    else k = 0;

    *year = y_delta + k - 80; // in DVB from 1900, b_tm from 1980
    *month = m_delta -1 - k*12 - 1; // in DVB 1-12, b_tm (0-11)
}