How to search and playback recordings on VRM or SD-Card when DST Flag is activated/ deactivated.
In order to determine the Time Zone values, perform the bit mask operation of the flag value with the combined bit mask value 0x1F800000 as shown below. Bits 23-28 correspond to the Time Zone bits in the Flags.
Bit Bit
31 0
01101000 0000 0100 0100 1111 0100 0001 (flag value = 0x68044f41)
00011111 1000 0000 0000 0000 0000 0000 (combined bit mask value =0x1F800000. The time zone mask bits 23-28 are set)
(Apply the bit mask (AND) operation)
-----------------------------------------------------------
0000 1000 0000 0000 0000 0000 0000 0000
------------------------------------------------------------
In this case the 27th bit is set and the value 010000= 16 quarter hours = 4 hours offset (DST is on, only indicated by the time and not by any flag).
In order to determine the Time Zone Sign, perform the bit mask operation of the flag value with the mask value 0x20000000 as shown below. Bit 29 corresponds to the Time Zone Sign in the Flags.
0110 1000 0000 0100 0100 1111 0100 0001 (flag value = 0x68044f41)
0010 0000 0000 0000 0000 0000 0000 0000 (mask value = 0x20000000)
(Apply the bit mask (AND) operation)
------------------------------------------------------------
0010 0000 0000 0000 0000 0000 0000 0000
-------------------------------------------------------------
In this case the 29th bit is set which indicates the Time Zone Sign is on
This article is an appendix to the following " How to Search and Playback" article. |