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Class: VideoCapture

@geenee/armature.VideoCapture

Video capture

VideoCapture object provides means to grab images from a source. It implements all required functionality including video device initialization, setup, start/stop of capture and frame grabbing. Internally VideoCapture utilizes ImageBuffer as storage.

Hierarchy

Constructors

constructor

new VideoCapture()

Constructor

Overrides

VideoSource.constructor

Properties

buffer

buffer: ImageBuffer

Context of original stream

Inherited from

VideoSource.buffer


captureTime

captureTime: number = 0

Timestamp of the last captured frame

Inherited from

VideoSource.captureTime


sizeMax

Protected Optional sizeMax: number

Maximum capture resolutions

Inherited from

VideoSource.sizeMax


videoRef

Protected videoRef: HTMLVideoElement

Video element

Methods

addListener

addListener<E>(event, listener): VideoCapture

Adds the listener function to the end of the listeners array

Type parameters

NameType
Eextends "resize"

Parameters

NameTypeDescription
eventEThe name of the event
listenerCaptureEvents[E]The callback function

Returns

VideoCapture

This EventEmitter

Inherited from

VideoSource.addListener


capture

capture(): boolean

Grab the next video frame

VideoCapture grabs the next image from a video source (camera) and stores it in embedded ImageBuffer.

Returns

boolean

True if next frame was available and grabbed

Overrides

VideoSource.capture


dispose

dispose(): void

Dispose video capture object

Returns

void

Overrides

VideoSource.dispose


emit

emit<E>(event, ...args): boolean

Synchronously calls each of the listeners registered for the event

Type parameters

NameType
Eextends "resize"

Parameters

NameTypeDescription
eventEThe name of the event
...argsArgs<CaptureEvents[E]>Arguments passed to the listeners

Returns

boolean

True if the event had listeners, False otherwise

Inherited from

VideoSource.emit


eventNames

eventNames(): (string | symbol)[]

List of emitter's events

Returns

(string | symbol)[]

List of emitter's events

Inherited from

VideoSource.eventNames


getMaxListeners

getMaxListeners(): number

Maximum number of listeners per event

Returns

number

Maximum number of listeners per event

Inherited from

VideoSource.getMaxListeners


listenerCount

listenerCount<E>(event): number

The number of listeners listening to the event

Type parameters

NameType
Eextends "resize"

Parameters

NameTypeDescription
eventEThe name of the event

Returns

number

Number of listeners

Inherited from

VideoSource.listenerCount


listeners

listeners<E>(event): Function[]

Copy of the array of listeners for the event

Type parameters

NameType
Eextends "resize"

Parameters

NameTypeDescription
eventEThe name of the event

Returns

Function[]

Copy of the listeners array

Inherited from

VideoSource.listeners


off

off<E>(event, listener): VideoCapture

Removes the listener from the listener array for the event

Type parameters

NameType
Eextends "resize"

Parameters

NameTypeDescription
eventEThe name of the event
listenerCaptureEvents[E]The callback function

Returns

VideoCapture

This EventEmitter

Inherited from

VideoSource.off


on

on<E>(event, listener): VideoCapture

Adds the listener function to the event

Type parameters

NameType
Eextends "resize"

Parameters

NameTypeDescription
eventEThe name of the event
listenerCaptureEvents[E]The callback function

Returns

VideoCapture

This EventEmitter

Inherited from

VideoSource.on


once

once<E>(event, listener): VideoCapture

Adds a one-time listener function for the event

Type parameters

NameType
Eextends "resize"

Parameters

NameTypeDescription
eventEThe name of the event
listenerCaptureEvents[E]The callback function

Returns

VideoCapture

This EventEmitter

Inherited from

VideoSource.once


pause

pause(): void

Pause video capture

Returns

void

Overrides

VideoSource.pause


prependListener

prependListener<E>(event, listener): VideoCapture

Adds the listener function to the beginning of the listeners array

Type parameters

NameType
Eextends "resize"

Parameters

NameTypeDescription
eventEThe name of the event
listenerCaptureEvents[E]The callback function

Returns

VideoCapture

This EventEmitter

Inherited from

VideoSource.prependListener


prependOnceListener

prependOnceListener<E>(event, listener): VideoCapture

Adds a one-time listener function to the beginning of the listeners array

Type parameters

NameType
Eextends "resize"

Parameters

NameTypeDescription
eventEThe name of the event
listenerCaptureEvents[E]The callback function

Returns

VideoCapture

Inherited from

VideoSource.prependOnceListener


ratio

ratio(): number

Aspect ratio of the video stream

Returns

number

Aspect ratio of the video stream

Inherited from

VideoSource.ratio


rawListeners

rawListeners<E>(event): Function[]

Copy of the array of listeners for the event including wrappers

Type parameters

NameType
Eextends "resize"

Parameters

NameTypeDescription
eventEThe name of the event

Returns

Function[]

Copy of the listeners array

Inherited from

VideoSource.rawListeners


removeAllListeners

removeAllListeners<E>(event?): VideoCapture

Removes all listeners, or those of the specified event

Type parameters

NameType
Eextends "resize"

Parameters

NameTypeDescription
event?EThe name of the event

Returns

VideoCapture

This EventEmitter

Inherited from

VideoSource.removeAllListeners


removeListener

removeListener<E>(event, listener): VideoCapture

Removes the specified listener from the listener array

Type parameters

NameType
Eextends "resize"

Parameters

NameTypeDescription
eventEThe name of the event
listenerCaptureEvents[E]The callback function

Returns

VideoCapture

This EventEmitter

Inherited from

VideoSource.removeListener


reset

reset(): void

Reset video capture

After reset() capture may be started again only after setup().

Returns

void

Overrides

VideoSource.reset


setMaxListeners

setMaxListeners(n): VideoCapture

Sets maximum number of listeners per event

Parameters

NameTypeDescription
nnumberMaximum number of listeners

Returns

VideoCapture

This EventEmitter

Inherited from

VideoSource.setMaxListeners


setup

setup(params?): Promise<boolean>

Setup video capture

Sets up video device, streams and contexts with canvases. Video capture can be setup by simplified VideoParams opening default front/rear camera with provided resolution, custom MediaStreamConstraints providing the most flexible way to select the video stream (for example set deviceId), external MediaStream allowing use of custom video sources, or defining a media file as source of video stream by string url or FileParams that additionally allows to set maximum size in cases resolution is too big for a device.

Parameters

NameTypeDescription
params?VideoSourceParamsParameters of video capture

Returns

Promise<boolean>

Promise resolved to the status of setup when finished

Overrides

VideoSource.setup


size

size(): Size

Resolution of the video stream

Returns

Size

Resolution of the video stream

Inherited from

VideoSource.size


start

start(): Promise<void>

Start video capture

Video capture can be started only after successful setup().

Returns

Promise<void>

Promise resolved when capture is started

Overrides

VideoSource.start


updateSize

Protected updateSize(size): void

Update callback on video resize

Parameters

NameTypeDescription
sizeSizeNew size of the video stream

Returns

void

Inherited from

VideoSource.updateSize