USB视频类规范1.5版解读

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"UVC 1.5 Class specification.pdf 是一份关于USB视频类（USB VIDEO CLASS）的设备规范文档，详细定义了USB Video Device Class的1.5版本，由多个业界专家共同编写，涵盖多个知名公司如 Cypress Semiconductor、Dolby Labs、Google、Intel、Logitech、Microsoft、SMSC 和 Texas Instruments等的贡献。该文档发布于2012年8月9日，旨在为USB视频设备提供统一的标准和接口，以实现不同设备间的兼容性和互操作性。" 《USB Video Class 1.5 规范详解》 USB Video Class（UVC）是一种USB设备类别，允许USB设备（如网络摄像头、视频捕获设备等）与主机之间进行视频数据传输。UVC 1.5是这个类别的一个关键更新，它在原有的1.0和1.1版本基础上增加了新的功能和改进，以适应高速发展的视频技术需求。 UVC 1.5的主要特性包括： 1. **高清视频支持**：UVC 1.5引入了对高分辨率视频流的支持，如4K Ultra HD和更高分辨率，这使得高清视频录制和传输成为可能，满足了多媒体应用的需求。 2. **增强型编码支持**：除了原有的MJPEG和YUV编码格式，1.5版本增加了对H.264等高效视频编码格式的支持，提高了视频压缩效率，降低了带宽需求。 3. **多流传输**：UVC 1.5允许设备同时传输多个独立的视频流，可以用于多视图显示、视频会议等场景，增强了设备的灵活性和应用范围。 4. **实时编解码器协商**：设备和主机可以动态协商最佳的编解码设置，以优化性能和资源利用。 5. **USB 3.0/USB 3.1兼容**：UVC 1.5针对USB 3.0及更高版本的高速接口进行了优化，提供更高的传输速度，减少了延迟，提高了用户体验。 6. **设备状态报告**：新规范包含了更详细的设备状态报告机制，使主机能够更好地监控设备的运行状况和错误处理。 7. **电源管理**：改进的电源管理功能允许设备在不使用时进入低功耗模式，节省能源。 8. **扩展配置**：UVC 1.5允许设备提供多种配置，以适应不同的应用场景和性能需求。 9. **厂商特定扩展**：尽管UVC提供了标准化的接口，但也允许厂商添加自己的私有扩展，以实现独特的功能或优化。这份规范文档详细阐述了UVC 1.5的架构、接口、数据格式、控制管道、传输机制等方面，是开发者和制造商设计符合标准的USB视频设备的重要参考。通过遵循UVC 1.5规范，设备制造商可以确保其产品与各种操作系统（如Windows、Mac OS和Linux）以及应用软件的无缝集成。

USB Device Class Definition for Video Devices

Revision 1.5 August 9, 2012 1

1 Introduction

1.1 Purpose

This document describes the minimum capabilities and characteristics that a video streaming

device must support to comply with the USB Video Class specification.

It defines and standardizes video streaming functionality on the USB, and contains all necessary

information for a designer to build a USB-compliant device that incorporates video streaming

functionality. It specifies the standard and class-specific descriptors that must be present in each

USB video function. It further explains the use of class-specific requests that allow for full video

streaming control. Finally, it explains how devices can be compliant with multiple versions of

this specification to enable backwards compatibility.

Devices that conform to this specification will be referred to as USB Video Class devices.

1.2 Scope

The USB Device Class Definition for Video Devices applies to all devices or functions within

composite devices that are used to manipulate video and video-related functionality. This would

include devices such as desktop video cameras (or "webcams"), digital camcorders, analog video

converters, analog and digital television tuners, and still-image cameras that support video

streaming. This specification also applies to Video Devices that compress video using temporal

encoders.

1.3 Related Documents

USB Specification Revision 3.0, November 12, 2008, www.usb.org

USB Specification Revision 2.0, April 27, 2000, www.usb.org

Interface Association Descriptor ECN, www.usb.org

1.4 Document Conventions

The following typographic conventions are used:

 Italic Documents references

 Bold Request fields

 UPPERCASE Constants

The following terms are defined:

 Expected

a keyword used to describe the behavior of the hardware or software in the design models

assumed by this specification. Other hardware and software design models may also be

implemented

 May/Could

a keyword that indicates flexibility of choice with no implied preference.

USB Device Class Definition for Video Devices

Revision 1.5 August 9, 2012 3

Host

Computer system where a Host Controller is installed.

Host Controller

Hardware that connects a Host to the USB.

Host Software

Generic term for a collection of drivers, libraries and/or applications that

provide operating system support for a device.

IAD

Interface Association Descriptor. This is used to describe that two or

more interfaces are associated to the same function. An ‘association’

includes two or more interfaces and all of their alternate setting

interfaces.

IDR

Instantaneous Decoder Refresh. An I-Frame where no frames after the

IDR frame can rely on frames before the IDR frame.

Interface

An Entity representing a collection of zero or more endpoints that

present functionality to a Host.

Input Terminal.

Dependency Layer

The same as dependency representation in the H.264 specification and

in the VP8 payload specification.

Multicast Streaming

Two or more independent video streams originating from the same

source (Video Function) sent over separate video streaming interfaces..

Output Terminal.

Payload Transfer

In the context of the USB Video Class, a Payload Transfer is a unit of

data transfer common to bulk and isochronous endpoints. Each Payload

Transfer includes a Payload Header followed by Payload Data. For

isochronous endpoints, a Payload Transfer is contained in the data

transmitted during a single (micro) frame: up to 1023 bytes for a full-

speed endpoint; up to 1024 bytes for a high-speed endpoint; and up to

3072 bytes for a high-speed/high-bandwidth endpoint. For bulk

endpoints, a Payload Transfer is contained in the data transmitted in a

single bulk transfer (which may consist of multiple bulk data

transactions).

Payload Data

Format-specific data contained in a Payload Transfer (excluding the

Payload Header).

Payload Header

A header at the start of each Payload Transfer that provides data framing

and encapsulation information.

PTS

Presentation Time Stamp. This is the source clock time in native device

clock units when the raw frame capture begins.

Processing Unit.

Request

A mechanism supported by the video function for the host software to

interact with a Control within an Entity.

Quantization Parameter. This is an index used to derive a scaling matrix

for video encoding.

Sample Transfer

A sample transfer is composed of one or more payload transfer(s)

representing a video sample.

SCR

Source Clock Reference. This is a two part value that contains (1) the

source clock time when the video sample leaves the device and (2) the

USB Device Class Definition for Video Devices

Revision 1.5 August 9, 2012 5

2 Functional Characteristics

The video function is located at the interface level in the device class hierarchy. It consists of a

number of interfaces grouping related pipes that together implement the interface to the video

function.

Video functions are addressed through their video interfaces. Each video function has a single

VideoControl (VC) interface and can have several VideoStreaming (VS) interfaces. The

VideoControl (VC) interface is used to access the device controls of the function whereas the

VideoStreaming (VS) interfaces are used to transport data streams into and out of the function.

The collection of the single VideoControl interface and the VideoStreaming interfaces that

belong to the same video function is called the Video Interface Collection (VIC). An Interface

Association Descriptor (IAD) is used to describe the Video Interface Collection.

2.1 Video Interface Class

The Video Interface class groups all functions that can interact with USB-compliant video data

streams. All functions that convert between analog and digital video domains can be part of this

class. In addition, those functions that transform USB-compliant video data streams into other

USB-compliant video data streams can be part of this class. Even analog video functions that are

controlled through USB belong to this class.

In fact, for a video function to be part of this class, the only requirement is that it exposes one

VideoControl Interface. No further interaction with the function is mandatory, although most

functions in the video interface class will support one or more optional VideoStreaming

interfaces for consuming or producing one or more video data streams.

The Video Interface class code is assigned by the USB. For details, see section A.1 "Video

Interface Class Code".

2.2 Video Interface Subclass and Protocol

The Video Interface class is divided into subclasses as identified by the Interface Subclass code.

The following two interface subclasses are defined in this specification.

 VideoControl Interface

 VideoStreaming Interface

The following Function Subclass is used in the Interface Association Descriptor.

 Video Interface Collection

The assigned codes can be found in sections A.2, "Video Interface Subclass Codes" and A.3,

"Video Interface Protocol Codes" of this specification. All other subclass codes are unused and

reserved except code 0xFF, which is reserved for vendor-specific extensions.

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USB视频类规范1.5版解读

UVC规范V1.5

uvc 官方协议v1.5

中文usb_video_class_1.1.pdf

uvc 1.5 class specification.pdf

UVC_1.5_Class specification.pdf.7z

USB_Video_Class_1.5.pdf.7z

usb uvc 1.5规范协议中文版.docx

USB Video Class 1_5.rar (USB_Video_Class_1.5.pdf等多个)

USB视频设备类定义1.5版：UVC 1.5规范详解

USB_Video_Class_1.5 Specification

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