uvc

README

github.com/kevmo314/go-uvc

An almost-pure-Go library for accessing UVC devices. The library currently depends on libusb via cgo but not libuvc. One day this may change but libusb is much more complex.

The non-Go equivalent of this library is libuvc.

Features

• UVC 1.5 support
  • Input terminals (recording from cameras)
  • Output terminals (displaying images on a device)
• Isochronous and bulk transfer support
• Android support
• Video decoding API
• Camera controls
• UAC Audio support

Demo

go-uvc includes a debugging tool (the screenshot above) to connect to and debug cameras. To use it,

go run github.com/kevmo314/go-uvc/cmd/inspect -path /dev/bus/usb/001/002

Usage

A minimal example of how you might use go-uvc.

package main

import (
	"image/jpeg"
	"fmt"
	"log"
	"syscall"

	"github.com/kevmo314/go-uvc"
	"github.com/kevmo314/go-uvc/pkg/descriptors"
)

func main() {
	fd, err := syscall.Open("/dev/bus/usb/001/002", syscall.O_RDWR, 0)
	if err != nil {
		panic(err)
	}

	ctx, err := uvc.NewUVCDevice(uintptr(fd))
	if err != nil {
		panic(err)
	}

	info, err := ctx.DeviceInfo()
	if err != nil {
		panic(err)
	}

	for _, iface := range info.StreamingInterfaces {
		for i, desc := range iface.Descriptors {
			fd, ok := desc.(*descriptors.MJPEGFormatDescriptor)
			if !ok {
				continue
			}
			frd := iface.Descriptors[i+1].(*descriptors.MJPEGFrameDescriptor)

			resp, err := iface.ClaimFrameReader(fd.Index(), frd.Index())
			if err != nil {
   				panic(err)
			}

			for i := 0; ; i++ {
				fr, err := resp.ReadFrame()
				if err != nil {
   					panic(err)
				}
				img, err := jpeg.Decode(fr)
				if err != nil {
					continue
				}
    				// do something with img
			}
		}
	}
}

Documentation

Index

• Constants
• Variables
• type CameraTerminal
  • func (ct *CameraTerminal) Get(desc descriptors.CameraTerminalControlDescriptor) error
  • func (ct *CameraTerminal) GetSupportedControls() []descriptors.CameraTerminalControlDescriptor
  • func (ct *CameraTerminal) IsControlRequestSupported(desc descriptors.CameraTerminalControlDescriptor) bool
  • func (ct *CameraTerminal) Set(desc descriptors.CameraTerminalControlDescriptor) error
• type ControlInterface
• type DeviceInfo
  • func (d *DeviceInfo) Close() error
• type EncodingUnitControlSelector
• type EndpointDescriptorSubtype
• type ExtensionUnitControlSelector
• type InterfaceControlSelector
• type ProcessingUnit
  • func (pu *ProcessingUnit) Get(desc descriptors.ProcessingUnitControlDescriptor) error
  • func (pu *ProcessingUnit) GetSupportedControls() []descriptors.ProcessingUnitControlDescriptor
  • func (pu *ProcessingUnit) IsControlRequestSupported(desc descriptors.ProcessingUnitControlDescriptor) bool
  • func (pu *ProcessingUnit) Set(desc descriptors.ProcessingUnitControlDescriptor) error
• type RequestCodes
• type SelectorUnitControlSelector
• type TerminalControlSelector
• type UVCDevice
  • func NewUVCDevice(fd uintptr) (*UVCDevice, error)
  • func (d *UVCDevice) Close() error
  • func (d *UVCDevice) DeviceInfo() (*DeviceInfo, error)
  • func (d *UVCDevice) IsTISCamera() (bool, error)

Constants

const (
	EndpointDescriptorSubtypeUndefined EndpointDescriptorSubtype = 0x00
	EndpointDescriptorSubtypeGeneral                             = 0x01
	EndpointDescriptorSubtypeEndpoint                            = 0x02
	EndpointDescriptorSubtypeInterrupt                           = 0x03
)

const (
	RequestCodesUndefined RequestCodes = 0x00
	RequestCodesSetCur                 = 0x01
	RequestCodesSetCurAll              = 0x11
	RequestCodesGetCur                 = 0x81
	RequestCodesGetMin                 = 0x82
	RequestCodesGetMax                 = 0x83
	RequestCodesGetRes                 = 0x84
	RequestCodesGetLen                 = 0x85
	RequestCodesGetInfo                = 0x86
	RequestCodesGetDef                 = 0x87
	RequestCodesGetCurAll              = 0x91
	RequestCodesGetMinAll              = 0x92
	RequestCodesGetMaxAll              = 0x93
	RequestCodesGetResAll              = 0x94
	RequestCodesGetDefAll              = 0x97
)

const (
	InterfaceControlSelectorUndefined               InterfaceControlSelector = 0x00
	InterfaceControlSelectorVideoPowerModeControl                            = 0x01
	InterfaceControlSelectorRequestErrorCodeControl                          = 0x02
)

const (
	EncodingUnitControlSelectorUndefined                 EncodingUnitControlSelector = 0x00
	EncodingUnitControlSelectorSelectLayerControl                                    = 0x01
	EncodingUnitControlSelectorProfileToolsetControl                                 = 0x02
	EncodingUnitControlSelectorVideoResolutionControl                                = 0x03
	EncodingUnitControlSelectorMinFrameIntervalControl                               = 0x04
	EncodingUnitControlSelectorSliceModeControl                                      = 0x05
	EncodingUnitControlSelectorRateControlModeControl                                = 0x06
	EncodingUnitControlSelectorAverageBitrateControl                                 = 0x07
	EncodingUnitControlSelectorCPBSizeControl                                        = 0x08
	EncodingUnitControlSelectorPeakBitRateControl                                    = 0x09
	EncodingUnitControlSelectorQuantizationParamsControl                             = 0x0A
	EncodingUnitControlSelectorSyncRefFrameControl                                   = 0x0B
	EncodingUnitControlSelectorLTRBufferControl                                      = 0x0C
	EncodingUnitControlSelectorLTRPictureControl                                     = 0x0D
	EncodingUnitControlSelectorLTRValidationControl                                  = 0x0E
	EncodingUnitControlSelectorLevelIDCControl                                       = 0x0F
	EncodingUnitControlSelectorSEIPayloadTypeControl                                 = 0x10
	EncodingUnitControlSelectorQPRangeControl                                        = 0x11
	EncodingUnitControlSelectorPriorityControl                                       = 0x12
	EncodingUnitControlSelectorStartOrStopLayerControl                               = 0x13
	EncodingUnitControlSelectorErrorResiliencyControl                                = 0x14
)

Variables

var (
	ErrInvalidDescriptor = errors.New("invalid descriptor")
)

Types

type CameraTerminal

type CameraTerminal struct {
	CameraDescriptor *descriptors.CameraTerminalDescriptor
	// contains filtered or unexported fields
}

func (*CameraTerminal) Get

func (ct *CameraTerminal) Get(desc descriptors.CameraTerminalControlDescriptor) error

func (*CameraTerminal) GetSupportedControls

func (ct *CameraTerminal) GetSupportedControls() []descriptors.CameraTerminalControlDescriptor

func (*CameraTerminal) IsControlRequestSupported

func (ct *CameraTerminal) IsControlRequestSupported(desc descriptors.CameraTerminalControlDescriptor) bool

func (*CameraTerminal) Set

func (ct *CameraTerminal) Set(desc descriptors.CameraTerminalControlDescriptor) error

type ControlInterface

type ControlInterface struct {
	CameraTerminal *CameraTerminal
	ProcessingUnit *ProcessingUnit
	Descriptor     descriptors.ControlInterface
}

type DeviceInfo

type DeviceInfo struct {
	ControlInterfaces   []*ControlInterface
	StreamingInterfaces []*transfers.StreamingInterface
	// contains filtered or unexported fields
}

func (*DeviceInfo) Close

func (d *DeviceInfo) Close() error

type EncodingUnitControlSelector

type EncodingUnitControlSelector int

type EndpointDescriptorSubtype

type EndpointDescriptorSubtype int

type ExtensionUnitControlSelector

type ExtensionUnitControlSelector int

const (
	ExtensionUnitControlSelectorUndefined ExtensionUnitControlSelector = 0x00
)

type InterfaceControlSelector

type InterfaceControlSelector int

type ProcessingUnit

type ProcessingUnit struct {
	UnitDescriptor *descriptors.ProcessingUnitDescriptor
	// contains filtered or unexported fields
}

func (*ProcessingUnit) Get

func (pu *ProcessingUnit) Get(desc descriptors.ProcessingUnitControlDescriptor) error

func (*ProcessingUnit) GetSupportedControls

func (pu *ProcessingUnit) GetSupportedControls() []descriptors.ProcessingUnitControlDescriptor

func (*ProcessingUnit) IsControlRequestSupported

func (pu *ProcessingUnit) IsControlRequestSupported(desc descriptors.ProcessingUnitControlDescriptor) bool

func (*ProcessingUnit) Set

func (pu *ProcessingUnit) Set(desc descriptors.ProcessingUnitControlDescriptor) error

type RequestCodes

type RequestCodes int

type SelectorUnitControlSelector

type SelectorUnitControlSelector int

const (
	SelectorUnitControlSelectorUndefined SelectorUnitControlSelector = 0x00
	SelectorUnitInputSelectControl                                   = 0x01
)

type TerminalControlSelector

type TerminalControlSelector int

const (
	TerminalControlSelectorUndefined TerminalControlSelector = 0x00
)

type UVCDevice

type UVCDevice struct {
	// contains filtered or unexported fields
}

func NewUVCDevice

func NewUVCDevice(fd uintptr) (*UVCDevice, error)

func (*UVCDevice) Close

func (d *UVCDevice) Close() error

func (*UVCDevice) DeviceInfo

func (d *UVCDevice) DeviceInfo() (*DeviceInfo, error)

func (*UVCDevice) IsTISCamera

func (d *UVCDevice) IsTISCamera() (bool, error)