Pre-alarm Recording
For added security centralized storage is frequently used to record alarm video for easy alarm verification and long-term secure storage. Pre-alarm recording is offered by introducing a buffer in the encoder so that the seconds or minutes of video before and after an alarm can be automatically transmitted to the centralized storage. Because of the huge edge storage capacities of some encoders, ranging from 256 MB to 800 GB, you can continuously record video at high frame rates and high resolutions, and still take advantage of pre-alarm recording. For instance, if you continuously transmit a 1 Mbit/s stream (30 IPS at 4 CIF) to a central recorder in the anticipation that an alarm event will occur, you will consume 1 Mbit/s of network bandwidth, or send about 11 Gigabytes of video data. If, however, you use Recording at the Edge, and use pre-alarm recording configured to 5 seconds pre- and 10 seconds post-alarm, then assuming 20 alarms per day you will transmit a much lower total of around 40 Megabytes of video. The same 11 GB will still be recorded locally but only 40 MB, or 0.4% of it, will touch the network.
In those instances where the pre-alarm video is not long enough, it is comforting to know that the original complete video is always available, recorded at the edge.
Read more about this topic: Recording At The Edge
Famous quotes containing the word recording:
“He shall not die, by G—, cried my uncle Toby.
MThe ACCUSING SPIRIT which flew up to heaven’s chancery with the oath, blush’d as he gave it in;—and the RECORDING ANGEL as he wrote it down, dropp’d a tear upon the word, and blotted it out for ever.”
—Laurence Sterne (1713–1768)