Bit rate is the amount of data a video stream produces per second, measured in kilobits or megabits. It combines with retention time and camera count to set storage volume, and it is the figure a network has to carry. A higher bit rate carries more detail and motion but costs space and bandwidth.
Bit rate is the bridge between a picture and the storage it requires. A camera’s settings decide it, and the recorder’s disk and the network then have to accommodate it.
What changes the bit rate
Resolution, frame rate, scene activity, compression and the encoder’s quality setting all move it. A busy entrance produces more data than an empty corridor at the same settings. Two cameras from different manufacturers at the same resolution can differ noticeably, so read the figure from the device.
Reading the recorder’s numbers
Recorders show a per-channel bit rate in live view or in the camera settings. Use that rather than a datasheet maximum. Multiply it by recording hours and channel count to estimate daily storage, then check the total against the disk and the network the recorder sits on.