Cctv: Video Compression in Dvrs

DVR stands for Digitals Video Recorder. Advantage of using a DVR technology over analog recording is that the Digital Data recorded by DVR can be compressed and saved in special hard disk and can be reviewed later. Video compression plays an important role in overall operation, properly compressed video can also save disk space.

All DVRs use some kind of compression algorithm called a codec to keep the digital video files at a manageable size. The average size of an uncompressed still image frame at 320×240 resolution in 24-bit true color is about 230400 Byte or 2.3 Mega Byte. Same image frame in 32 bit color is about 307200 Byte or 3.07 Mega Byte.

An hour’s worth of one channel of uncompressed video at 25 frames per second would take up 21,600 megabytes (21.6 GB)

Frame size 320*240 Pixel at 25 frames per second would take up

25*3600* 230400 Byte = 20736 Mega bytes

= 20.736 GB (24 bit color)

25*3600* 307200 Byte = 27648 Mega bytes

= 27.648 GB (32 bit color)