April 22, 2011
68013 UVC, first of all, must be added in dscr.a51 in the UVC descriptor.
agreement in USB Video class_1.0a example, there is a descriptor structure:
dark part of the UVC-specific descriptors, the other is USB2.0 descriptors.
with UVC device topology:
The following brief analysis of their correspondence.
1: UVC is the interface layer, there are two interfaces VideoControl Interface and VideoStreaming Interface.
2: GM are:
Device Descriptor
Device Quality Dscriptor
Confaguration Descriptor
< br /> above are not related to the USB interface layer, is only related to the device.
3: Then enter the USB interface layer, starting with UVC proprietary interface definition.
descriptors include:
◆ Interface Association Descriptor – IAD Interface co-descriptors, used to describe the relationship between the various interfaces, UVC has two interfaces, VC Interface and VS interfaces
here describes the VC interface and relationship between the VS interface. This class is the interface layer used CC_ (Class Codes) and SC_ (Subclass Codes)
then define the following into the VC interface descriptor section, which contains many elements, interface 0 is part of the figure dashed :
◆ Standard VC Interface Descriptor – standard VC interface descriptor, the interface uses the default channel 0 interrupt mode to transfer data, dealing mainly with UVC class request,
without the specific video data transmission. Interface class is used CC_ and SC_.
◆ Class-specific VC Interface Descriptor – special / proprietary class of VC interface descriptor, define the VC interface to achieve the function. Video special class descriptor for the CS_
(Class-Specific) and VC_ (Video Class-Specific Interface descriptor Subtypes)
start the following definition of VC interface descriptor in each unit :
◆ Input Terminal Descriptor (Camera) – IT descriptors, UVC it ??is the camera, and use the interface class CS_, VC_, ITT_
[Valley ]
2011 年 4 Friday, 22 February at 18:25:01 Xin Mao Rabbit Lunar March