Composite Video Signal in Automotive Application: Past and Future

Analog video decoders are used to convert analog composite video into digital data to be further processed by the SoC for vision based automotive applications. From the original composite signal (CVBS) that delivers 0.3M pixels per frame to current camera's 4M pixels per frame, Richnex's decoder product line covers entire CVBS resolution spectrum in automotive and machine vision area.
 

Standard Definition Video Camera System

SD composite signal has been adopted in early rear view camera systems with its resolution and format compatible with the standard TV baseband signal of either NTSC or PAL broadcasting system. The NTSC video offers SD resolution (720x480 pixels) and interlaced fields of 60 fps. Interlacing improves overall perception of motion with limited bandwith requirement. The dynamic range of the SD sensor is usually superior to its HD counterpart due to the bigger sensor pixel size. SD camera with composite (CVBS) output is still found in OEM and AM vehicles for its time-tested technology and cost effectiveness in rear view camera system.

 

HD Camera System

Composite video signal can be extended to transport higher video resolutions, in general with increased luma and chroma bandwidth as well as the color carrier frequency, allow video resolution of HD, FHD, 2K, 4K be implemented using the idea of frequency scaling of the original NTSC/PAL composite signal. In addition, progressive is usually adopted instead of interlaced video format. Even the 4K 30 fps analog video can fit within 100MHz bandwith which is orders lower bandwith required by a typical serdes transmission of same resolution.
 

UHD Roadmap

UHD, ultra high definition, is a 4K 30fps video format, and Richnex is developing the decoder for the UHD resolution. UHD can be used in AD application and its is a much more cost effective solution comparing to serdes based system cost. Based on Richnex's latest product of 2K/30 decoder, adding the 4K video decoder will further demonstrate the superior performance and bandwith utilization of analog video system.