Mac Webcams And The UVC 1.5 Specification : USB Video Class Cameras
Filed in: UVC Web Cameras
UVC compatibility was an important development for the Mac compatible webcam market. With UVC drivers built into OSX 10.4 and up, custom Mac OSX webcam drivers (of which few even existed) no longer needed to be installed for the camera hardware to be recognized. 'They Just Worked' by plugging them into a USB 2.0 or faster port. UVC eventually became the DEFACTO standard preferred for web cameras on all personal computing platforms: Mac OS, Windows, as well as Linux.
USB Video Class compliance isn't just for webcams. Analog video capture gadgets, Digital video cameras, still image cameras, USB TV tuners and other video devices can leverage the evolving UVC device specification. The latest version of the spec is now at v1.5 and is incorporated into (notably) some of Logitech's most recent premium webcams for Mac and PC.
The USB-IF Video working group at USB.org is chartered with updating the current USB Video Class (UVC) specification to natively support modern encoders like H.264. H.264 is an open standard that allows highly efficient video compression techniques for reducing the use of network bandwidth as well as significantly decreasing drive storage space requirements.The USB-IF working group also addresses known limitations with the UVC Specification and adopts new features to address evolving product technologies and market demands. Area of interest to the UVC working group include:
- Native H.264 support - Flexible metadata for each video frame - A windowing API for digital sensors - Ability to set a Region of Interest in the camera's field of view - Support for additional color spaces and color depths
- QOS - Quality Of Service scaling and negotiation - Support for additional video codecs - Support for multi-view stream management - Support for scene content depth information
In terms of the latest UVC 1.5 spec, H.264 and QOS matter a lot. There so many different video devices - from cell phones to PC and Mac desktop computers to dedicated group conferencing platforms. Available internet bandwidth can vary greatly. And delivering the optimal video resolution, image quality, or frame and data rates appropriate for each device is an important challenge the UVC committee strives to address.