dvb/si/datetime: Add more helper functions.

dvb/si/datetime.h

@@ -4,6 +4,7 @@
  * Copyright (C) 2009-2010 VideoLAN
  *
  * Authors: Christophe Massiot <massiot@via.ecp.fr>
+ *          Georgi Chorbadzhiyski <georgi@unixsol.org>
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the
@@ -27,6 +28,9 @@
 
 #include <bitstream/common.h>
 
+#include <time.h>   /* gmtime_r, time_t */
+#include <stdio.h>  /* sprintf */
+
 /*
  * Normative references:
  *  - ETSI EN 300 468 V1.11.1 (2010-04) (SI in DVB systems)
@@ -63,6 +67,76 @@ static inline void dvb_mjd_get(uint16_t mjd, int *y, int *m, int *d)
     *m = mp - 1 - k * 12;
 }
 
+#define bcd2dec(__bcd) (int)((((__bcd) >> 4) * 10) + (__bcd) % 16)
+static inline void dvb_time_decode_bcd(uint32_t bcd, int *seconds, int *hour, int *min, int *sec) {
+    *hour = bcd2dec( (bcd >> 16) & 0xff );
+    *min  = bcd2dec( (bcd >>  8) & 0xff );
+    *sec  = bcd2dec(  bcd        & 0xff );
+    if (seconds)
+        *seconds = *hour * 3600 + *min * 60 + *sec;
+}
+#undef bcd2dec
+
+static inline time_t dvb_time_decode_UTC(uint64_t UTC_time) {
+    struct tm tm;
+    uint16_t mjd = (UTC_time >> 24) & 0xffff;
+    uint32_t bcd = UTC_time & 0xffffff;
+
+    dvb_mjd_get(mjd, &tm.tm_year, &tm.tm_mon, &tm.tm_mday);
+    /* DVB months are 1..12, struct tm needs 0..11 */
+    tm.tm_mon  -= 1;
+
+    dvb_time_decode_bcd(bcd, NULL, &tm.tm_hour, &tm.tm_min, &tm.tm_sec);
+
+    return timegm(&tm);
+}
+
+#define dec2bcd(__dec) (int)((((__dec)/10) << 4) + (__dec) % 10)
+static inline uint64_t dvb_time_encode_UTC(time_t ts) {
+    struct tm tm;
+    uint16_t mjd = 0;
+    uint32_t bcd = 0;
+
+    gmtime_r(&ts, &tm);
+
+    mjd = dvb_mjd_set(tm.tm_year, tm.tm_mon + 1, tm.tm_mday);
+
+    bcd  = dec2bcd(tm.tm_hour) << 16;
+    bcd |= dec2bcd(tm.tm_min ) << 8;
+    bcd |= dec2bcd(tm.tm_sec );
+
+    return (uint64_t)((uint64_t)mjd << 24) | bcd;
+}
+
+static inline uint32_t dvb_time_encode_duration(unsigned int duration_sec)
+{
+    unsigned int t_sec, t_min, t_hour, ret;
+    t_sec  = duration_sec % 60;
+    t_min  = (duration_sec - t_sec) / 60;
+    t_hour = (t_min - t_min % 60) / 60;
+    t_min  = t_min - t_hour * 60;
+
+    ret  = dec2bcd(t_hour) << 16;
+    ret |= dec2bcd(t_min ) << 8;
+    ret |= dec2bcd(t_sec );
+
+    return ret;
+}
+#undef dec2bcd
+
+static time_t dvb_time_format_UTC(uint64_t UTC_time, struct tm *tm, char *output) {
+    struct tm tm_local;
+    if (tm == NULL)
+        tm = &tm_local;
+    time_t ts = dvb_time_decode_UTC(UTC_time);
+    tm = gmtime_r(&ts, tm);
+    if (output)
+        sprintf(output, "%04d-%02d-%02d %02d:%02d:%02d UTC",
+            tm->tm_year+1900, tm->tm_mon+1, tm->tm_mday,
+            tm->tm_hour, tm->tm_min, tm->tm_sec);
+    return ts;
+}
+
 #ifdef __cplusplus
 }
 #endif