Pre-buffering (explained)

Pre-buffering is the ability to record audio and video before the actual triggering event occurs. This is useful when you want to record the audio or video that leads up to an event that triggers recording, for example, opening a door.

Pre-buffering is possible because the system continuously receives audio and video streams from the connected devices and temporarily stores them for the defined pre-buffer period.

If a recording rule is triggered, the temporary recordings are made permanent for the rule’s configured pre-recording time.
If no recording rule is triggered, the temporary recordings in the pre-buffer are automatically deleted after the defined pre-buffer time.

To use the pre-buffer function, the devices must be enabled and sending a stream to the system.

Storage of the temporary pre-buffer recordings

You can choose the storage location of the temporary pre-buffer recordings:

In the memory; the pre-buffer period is limited to 15 seconds.
On the disk (in the media database); you can choose all values.

Storage to the memory instead of to disk improves system performance, but is only possible for shorter pre-buffer periods.

When recordings are stored in the memory, and you make some of the temporary recordings permanent, the remaining temporary recordings are deleted and cannot be restored. If you need to be able to keep the remaining recordings, store the recordings on the disk.

Devices that support pre-buffering

Cameras, microphones and speakers support pre-buffering. For speakers, the streams are only sent when the XProtect Smart Client user uses the Talk to speaker function. This means that depending on how your speaker streams are triggered to be recorded there is little or no pre-buffering available.

In most cases, you set up speakers to record when the XProtect Smart Client user uses the Talk to speaker function. In such cases, no speaker pre-buffer is available.