source: svn/trunk/newcon3bcm2_21bu/BSEAV/lib/tspsi/tspsi_validate.c

/***************************************************************************
 *     Copyright (c) 2004-2005, 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: tspsi_validate.c $
 * $brcm_Revision: 2 $
 * $brcm_Date: 3/11/05 6:18p $
 *
 * Module Description:
 *
 * Revision History:
 *
 * $brcm_Log: /BSEAV/lib/tspsi/tspsi_validate.c $
 * 
 * 2   3/11/05 6:18p erickson
 * PR13415: add TS_Get_Message_Size
 * 
 * 1   2/7/05 11:33p dlwin
 * Merge down for release 2005_REFSW_MERGETOMAIN:
 * 
 * Irvine_BSEAVSW_Devel/3   10/20/04 2:14p marcusk
 * PR13054: Updated to take into account hardware padding bytes.
 * 
 * Irvine_BSEAVSW_Devel/2   8/19/04 1:14p erickson
 * PR12101: got working with magnum
 *
 * Irvine_BSEAVSW_Devel/1   8/19/04 10:28a erickson
 * PR12101: added platform-independent tspsi validation code
 *
 ****************************************************************/
#include "tspsi_validate.h"

/* taken from BSEAV/lib/mpeg2_ts_parse/ts_priv.h */
#define TS_PSI_TABLE_ID_OFFSET              0
#define TS_PSI_SECTION_LENGTH_OFFSET        1
#define TS_PSI_TABLE_ID_EXT_OFFSET          3
#define TS_PSI_CNI_OFFSET                   5
#define TS_PSI_SECTION_NUMBER_OFFSET        6
#define TS_PSI_LAST_SECTION_NUMBER_OFFSET   7

#define TS_READ_16( buf ) ((uint16_t)((buf)[0]<<8|(buf)[1]))
#define TS_PSI_GET_SECTION_LENGTH( buf )    (uint16_t)(TS_READ_16( &(buf)[TS_PSI_SECTION_LENGTH_OFFSET] ) & 0x0FFF)
#define TS_PSI_MAX_BYTE_OFFSET( buf )       (TS_PSI_GET_SECTION_LENGTH(buf) - 1)

bool TS_Filter_Compare(const uint8_t *msg, const uint8_t *inclMask, const uint8_t *exclMask,
        const uint8_t *coef, size_t filterSize )
{
        bool inclResult = true;
        bool exclResult = true;
        bool exclEnabled = false;
        size_t i;

        for( i = 0; i < filterSize; i++ )
        {
                if( (inclMask[i] | coef[i]) != (inclMask[i] | msg[i]) )
                {
                        inclResult = false;
                        break;
                }

                if( exclEnabled == false && exclMask[i] != 0xFF )
                {
                        exclEnabled = true;
                        exclResult = false;
                }

                if( (~exclMask[i] & coef[i]) != (~exclMask[i] & msg[i]) )
                {
                        exclResult = true;
                }
        }

#if 0
/* for debug to make sure the logic is right */
        if( !(inclResult && exclResult) )
        {
                printf("Incl: ");
                for( i = 0; i < filterSize; i++ )
                {
                        printf("%02x ", inclMask[i]);
                }
                printf("\nExcl: ");
                for( i = 0; i < filterSize; i++ )
                {
                        printf("%02x ", exclMask[i]);
                }
                printf("\nCoef: ");
                for( i = 0; i < filterSize; i++ )
                {
                        printf("%02x ", coef[i]);
                }
                printf("\n Msg: ");
                for( i = 0; i < filterSize; i++ )
                {
                        printf("%02x ", msg[i]);
                }
                printf("\n");
        }
#endif

        return inclResult && exclResult;
}

int TS_Get_Message_Size(const uint8_t *msg)
{
        size_t message_size = TS_PSI_GET_SECTION_LENGTH(msg) + 3;
        /* 
        The transport hardware automatically pads messages to be 32 bit aligned.
        Therefore, the message size must be increased to take this into account.
        */
        if( message_size%4 ) {
                message_size += 4-(message_size%4);
        }
        return message_size;
}

bool TS_Validate_Size( const uint8_t *msg, size_t size)
{
        size_t current_size = 0;
        while (current_size + TS_PSI_SECTION_LENGTH_OFFSET + 1 < size) {
                current_size += TS_Get_Message_Size(&msg[current_size]);
        }
        /* In the end, it must be exactly equal */
        return current_size == size;
}