So why do we need to understand bitrate and compression?
Ultimately, in order to accurately determine how much hard drive space you will need with your DVR you need to take into consideration the codec technology being implemented, image resolution size, the bit-rate/compression ratio, the amount of video activity, is the bitrate variable or constant, and if motion detection (setting the DVR to only record activity when the camera detects motion in its field of view) is being utilized. Next, calculate the number of cameras and how many frames per second you want to record on each.
Advanced DVR systems, will allow you to independently control each channel for:
• Image resolution
• Bit rate (constant/variable)
• Display frame rate
• Record frame rate
• Motion detection
When evaluating storage requirements remember to evaluate the quality of the video based upon the most intense circumstances. Bitrates can be reduced significantly, if there is minimal motion, but when it comes time to maximum motion, the image can be distorted.