Video can be recorded in many resolutions and can also be compressed through a variety of different methods to make file sizes smaller thus improving transfer speeds and reducing the overall cost of storage. At times, the term “high resolution” can be confused with true high definition video.
HD video is 1280 x 720 or 1920 x 1080, referring to the number of pixels used to create the image being recorded. Commonly, these are referred to as 720p or 1080i/p respectively. Even with the latest video compression technology, HD video files are still considerably larger than SD files. Below is an example of video file sizes using the latest H.264 main profile compression. Keep in mind not all in-car video systems are using this compression, which means file sizes for the same resolution could easily be much larger.
- 1 Hour SD video (720x480) = 1.0 GB
- 1 Hour HD Video (1280x720) = 2.3 GB
- 1 Hour HD Video (1920x1080) = 5.0 GB
Recording in HD will provide extremely clear video evidence, allowing you to read license plates, determine make, model and color of vehicles, and in some cases, even gather key details of a suspect’s appearance. Therefore the technology is very desirable when it relates to evidence, but agencies need to be informed of the financial impact of HD video so they can choose a manageable and affordable system.