Re: [PATCH 1/4] libdvbv5: do not adjust DVB time daylight saving

[Mauro Carvalho Chehab <mchehab+samsung@kernel.org>]

Em Sat,  7 Jul 2018 13:20:54 +0200
André Roth <neolynx@gmail.com> escreveu:

> This makes dvb_time available outside of EIT parsing, and
> struct tm to reflect the actual values received from DVB.
> 
> Signed-off-by: André Roth <neolynx@gmail.com>
> ---
>  lib/include/libdvbv5/descriptors.h | 11 +++++++++++
>  lib/include/libdvbv5/eit.h         | 10 ----------
>  lib/libdvbv5/descriptors.c         | 37 +++++++++++++++++++++++++++++++++++++
>  lib/libdvbv5/tables/eit.c          | 28 ----------------------------
>  4 files changed, 48 insertions(+), 38 deletions(-)
> 
> diff --git a/lib/include/libdvbv5/descriptors.h b/lib/include/libdvbv5/descriptors.h
> index cb21470c..31f4c73f 100644
> --- a/lib/include/libdvbv5/descriptors.h
> +++ b/lib/include/libdvbv5/descriptors.h
> @@ -47,6 +47,7 @@
>  #include <unistd.h>
>  #include <stdint.h>
>  #include <arpa/inet.h>
> +#include <time.h>
>  
>  /**
>   * @brief Maximum size of a table session to be parsed
> @@ -159,6 +160,16 @@ uint32_t dvb_bcd(uint32_t bcd);
>  void dvb_hexdump(struct dvb_v5_fe_parms *parms, const char *prefix,
>  		 const unsigned char *buf, int len);
>  
> +/**
> + * @brief Converts a DVB formatted timestamp into struct tm
> + * @ingroup dvb_table
> + *
> + * @param data		event on DVB time format
> + * @param tm		pointer to struct tm where the converted timestamp will
> + *			be stored.
> + */
> +void dvb_time(const uint8_t data[5], struct tm *tm);
> +
>  /**
>   * @brief parse MPEG-TS descriptors
>   * @ingroup dvb_table
> diff --git a/lib/include/libdvbv5/eit.h b/lib/include/libdvbv5/eit.h
> index 9129861e..5af266b1 100644
> --- a/lib/include/libdvbv5/eit.h
> +++ b/lib/include/libdvbv5/eit.h
> @@ -209,16 +209,6 @@ void dvb_table_eit_free(struct dvb_table_eit *table);
>  void dvb_table_eit_print(struct dvb_v5_fe_parms *parms,
>  			 struct dvb_table_eit *table);
>  
> -/**
> - * @brief Converts a DVB EIT formatted timestamp into struct tm
> - * @ingroup dvb_table
> - *
> - * @param data		event on DVB EIT time format
> - * @param tm		pointer to struct tm where the converted timestamp will
> - *			be stored.
> - */
> -void dvb_time(const uint8_t data[5], struct tm *tm);
> -

This seems to break the existing ABI.

>  #ifdef __cplusplus
>  }
>  #endif
> diff --git a/lib/libdvbv5/descriptors.c b/lib/libdvbv5/descriptors.c
> index 0683dc1b..ccec503c 100644
> --- a/lib/libdvbv5/descriptors.c
> +++ b/lib/libdvbv5/descriptors.c
> @@ -56,6 +56,14 @@
>  #include <libdvbv5/desc_ca_identifier.h>
>  #include <libdvbv5/desc_extension.h>
>  
> +#ifdef ENABLE_NLS
> +# include "gettext.h"
> +# include <libintl.h>
> +# define _(string) dgettext(LIBDVBV5_DOMAIN, string)
> +#else
> +# define _(string) string
> +#endif
> +
>  static void dvb_desc_init(uint8_t type, uint8_t length, struct dvb_desc *desc)
>  {
>  	desc->type   = type;
> @@ -1391,3 +1399,32 @@ void dvb_hexdump(struct dvb_v5_fe_parms *parms, const char *prefix, const unsign
>  		dvb_loginfo("%s%s %s %s", prefix, hex, spaces, ascii);
>  	}
>  }
> +
> +void dvb_time(const uint8_t data[5], struct tm *tm)
> +{
> +  /* ETSI EN 300 468 V1.4.1 */
> +  int year, month, day, hour, min, sec;
> +  int k = 0;
> +  uint16_t mjd;
> +
> +  mjd   = *(uint16_t *) data;
> +  hour  = dvb_bcd(data[2]);
> +  min   = dvb_bcd(data[3]);
> +  sec   = dvb_bcd(data[4]);
> +  year  = ((mjd - 15078.2) / 365.25);
> +  month = ((mjd - 14956.1 - (int) (year * 365.25)) / 30.6001);
> +  day   = mjd - 14956 - (int) (year * 365.25) - (int) (month * 30.6001);
> +  if (month == 14 || month == 15) k = 1;
> +  year += k;
> +  month = month - 1 - k * 12;
> +
> +  tm->tm_sec   = sec;
> +  tm->tm_min   = min;
> +  tm->tm_hour  = hour;
> +  tm->tm_mday  = day;
> +  tm->tm_mon   = month - 1;
> +  tm->tm_year  = year;
> +  tm->tm_isdst = -1; /* do not adjust */

It seems that the only real change here is that you replaced 1 by -1 here,
in order for the mktime() to not handle daylight saving time.

Why are you also moving this out of eit.c/eit.h?

> +  mktime( tm );
> +}
> +
> diff --git a/lib/libdvbv5/tables/eit.c b/lib/libdvbv5/tables/eit.c
> index a6ba566a..799e4c9a 100644
> --- a/lib/libdvbv5/tables/eit.c
> +++ b/lib/libdvbv5/tables/eit.c
> @@ -154,34 +154,6 @@ void dvb_table_eit_print(struct dvb_v5_fe_parms *parms, struct dvb_table_eit *ei
>  	dvb_loginfo("|_  %d events", events);
>  }
>  
> -void dvb_time(const uint8_t data[5], struct tm *tm)
> -{
> -  /* ETSI EN 300 468 V1.4.1 */
> -  int year, month, day, hour, min, sec;
> -  int k = 0;
> -  uint16_t mjd;
> -
> -  mjd   = *(uint16_t *) data;
> -  hour  = dvb_bcd(data[2]);
> -  min   = dvb_bcd(data[3]);
> -  sec   = dvb_bcd(data[4]);
> -  year  = ((mjd - 15078.2) / 365.25);
> -  month = ((mjd - 14956.1 - (int) (year * 365.25)) / 30.6001);
> -  day   = mjd - 14956 - (int) (year * 365.25) - (int) (month * 30.6001);
> -  if (month == 14 || month == 15) k = 1;
> -  year += k;
> -  month = month - 1 - k * 12;
> -
> -  tm->tm_sec   = sec;
> -  tm->tm_min   = min;
> -  tm->tm_hour  = hour;
> -  tm->tm_mday  = day;
> -  tm->tm_mon   = month - 1;
> -  tm->tm_year  = year;
> -  tm->tm_isdst = 1; /* dst in effect, do not adjust */
> -  mktime( tm );
> -}
> -
>  
>  const char *dvb_eit_running_status_name[8] = {
>  	[0] = "Undefined",



Thanks,
Mauro