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

• VideoSource

  ↳ VideoCapture

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

---

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

Name	Type
E	extends "resize"

Parameters

Name	Type	Description
event	E	The name of the event
listener	CaptureEvents[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

Name	Type
E	extends "resize"

Parameters

Name	Type	Description
event	E	The name of the event
...args	Args<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

Name	Type
E	extends "resize"

Parameters

Name	Type	Description
event	E	The 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

Name	Type
E	extends "resize"

Parameters

Name	Type	Description
event	E	The 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

Name	Type
E	extends "resize"

Parameters

Name	Type	Description
event	E	The name of the event
listener	CaptureEvents[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

Name	Type
E	extends "resize"

Parameters

Name	Type	Description
event	E	The name of the event
listener	CaptureEvents[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

Name	Type
E	extends "resize"

Parameters

Name	Type	Description
event	E	The name of the event
listener	CaptureEvents[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

Name	Type
E	extends "resize"

Parameters

Name	Type	Description
event	E	The name of the event
listener	CaptureEvents[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

Name	Type
E	extends "resize"

Parameters

Name	Type	Description
event	E	The name of the event
listener	CaptureEvents[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

Name	Type
E	extends "resize"

Parameters

Name	Type	Description
event	E	The 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

Name	Type
E	extends "resize"

Parameters

Name	Type	Description
event?	E	The 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

Name	Type
E	extends "resize"

Parameters

Name	Type	Description
event	E	The name of the event
listener	CaptureEvents[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

Name	Type	Description
n	number	Maximum 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 string defining a media file as source of video stream.

Parameters

Name	Type	Description
params?	VideoSourceParams	Parameters 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

Name	Type	Description
size	Size	New size of the video stream

Returns

void

Inherited from

VideoSource.updateSize