User's Manual

G4 DVR-M1N-RPH User Manual
Page 54 of 112
؍ Note: Locked recording can be overwritten and deleted only after the protection time is
removed.
x By Capacity is selected by default. In this case:
1) The SD card is overwritten by capacity. When the SD card storage space is less than 2
GB, overwriting starts, with files of 128 MB deleted each time.
2) Delete by channel number in sequence, and delete 250 M files of one channel at a
time. If this channel segment is less than 100 M, look for the next channel with a
longer duration.
x By Day:
1) By Day means that files are overwritten by configured days. Configurable days from
1-31 days.
2) If the number of days is configured to 1, the video will be saved for 1 day only. If the
number of days is configured to 31, the recording is overwritten after having being
saved for 31 days.
3) 31-day storage duration is only possible when the disk has sufficient space. If you
have set a 31-day duration but the recording is only available for 7 days, earlier
recordings will be overwritten immediately after the disk is full.
x Never: Overwriting is not enabled for main stream recording, mirror stream, sub-stream,
and alarm stream. Recording stops after the memory is full.
x Lock Duration
Recording locked days: specifies the day(s) that locked recordings are retained to prevents them
from being deleted earlier than expected. It is set to 7 days by default.
For details about how to lock recording, see Section 3.4.
x Pre-recording
In pre-recording, recording files generated before alarm triggering are extracted for event
analysis. The value ranges from 1 to 60 minutes and is 15 minutes by default.
1˅In normal recording, when an alarm is triggered, earlier recording with a duration indicated
by this parameter is extracted and marked as alarm recording. T1 to T3 is a normal recording.
After an alarm is generated at T3, the duration between T2 and T3 is marked as alarm