@virtualscenery/greenscreenstream
v3.0.2
Published
Genereate new MediaStreams or Canvas elements based on MediaStreams (webcam) with any background image/video. Greenscreen your webcam and enable virtual backgrounds in your web applications.
Downloads
8
Readme
About
GreenScreenStream provides a wide range of options for manipulating Mediastreams.
Generate a new MediaStream for <canvas>
& <video>
elements based on provided MediaStreamTrack and a background image/video just using JavaScript.
After processed and "green screened" you can capture the stream and use it in your WebRTC calls for instance.
All rendering is done in realtime using a WebGL2 pixel shader (glsl) and optionally machine-learning.
Install
npm i @virtualscenery/greenscreenstream
Examples
Below you find a few different examples of greenscreenstream.
ML based Virtual Background - Image Background
ML based Virtual Background - Video Background
ML based Virtual Background - WebGL Background
ML based Virtual Background - Hologram Effect
https://virtualscenery.github.io/greenscreenstream-examples/example/WebGL
Look here for implementation.
GreenScreenStream API
Contents
GreenScreenStream (Class)
GreenScreenMethod (Enum)
Vector2 (Class)
VideoResolution (Enum)
IGreenScreenConfig (Interface)
BodyPixMode (Enum)
IMaskSettings (Interface)
GreenScreenStream (Class)
Constructor
Creates an instance of GreenScreenStream
constructor(greenScreenMethod: GreenScreenMethod, resolution: VideoResolution | Vector2, canvas?: HTMLCanvasElement)
Methods
initialize
Initlializes the GreenScreenStream with the provided background (image or video) and settings.
initialize(backgroundUrl?: string, config?: GreenScreenConfig): Promise<boolean>
addVideoTrack
Adds a MediaStreamTrack
(i.e webcam)
addVideoTrack(track: MediaStreamTrack): Promise<void | any>;
start
Starts rendering the greenscreen. You can optionally set a fps maximum here
start(maxFps?: number): void
stop
Stops the rendering process.
Optionally stop the media streams.
Stopping the streams works only if there are no references to them
outside of greenscreenstream.
stop(stopMediaStreams?:boolean): void
captureStream
Capture the rendered result to a MediaStream that you apply to your <video>
element.
captureStream(fps?: number): MediaStream;
setBackground
Sets the virtual background to a new image or video. Can be done while GreenScreenStream is running.
setBackground(src: string): Promise<HTMLImageElement | HTMLVideoElement | Error>
setBodyPixModel
Swaps out the currently used BodyPixModel used in ml mode (GreenScreenMethod.VirtualBackground
) (See GreenScreenMethod (Enum))
setBodyPixModel(config: IGreenScreenConfig): Promise<void>
scaleImageToCanvas
Scales the passed in image to canvas size and returns a scaled copy of it. Gets called automatically everytime a new image background is set. The imageOptions defaults to the current size of the greenscreen canvas and high quality .
public async scaleImageToCanvas(image: HTMLImageElement, imageOptions?: ImageBitmapOptions): Promise<HTMLImageElement>
getColorsFromStream
Gets the most dominant color and a list (palette) of the colors most common in the provided MediaStreamTrack.
getColorsFromStream(): { palette: [number, number,number][], dominant: [number, number,number] } {
setChromaKey
Pass a mask (rgb), color to the shader , to use as a mask. Should be the dominant color
, or on of the palette
colors detected. See getColorsFromStream
setChromaKey(r: number, g: number, b: number, threshold?: number): void;
setRange
Range is used to decide the amount of color to be used from either foreground or background.Playing with this variable will decide how much the foreground and background blend together.
setMaskRange(x:number,y:number): void
dominant
Get the most dominant color based on imageData and number of pixels
dominant(imageData: ImageData, pixelCount: number): [number, number,number] {
palette
Get an Array of the most significant colors in the MediaTrack
pallette(imageData: ImageData, pixelCount: number): [number, number,number][] | null {
GreenScreenMethod (Enum)
Describes the method GreenScreenStream should use for applying a virtual background.GreenScreenMethod.VirtualBackground
uses a machine learning model (Tensorflow BodyPix)GreenScreenMethod.VirtualBackgroundUsingGreenScreen
works without a machine learning model and thus consumes much less performance,
but requires the user to have a green screen.
enum GreenScreenMethod {
VirtualBackground,
VirtualBackgroundUsingGreenScreen
}
VideoResolution (enum)
Describes resolution presets GreenScreenStream should use.
enum VideoResolution {
SD,
HD,
FullHD,
WQHD,
UHD
}
Vector2 (Class)
Describes a custom resolution that GreenScreenStream can use.
Constructor
Both values default to zero.
constructor(x?: number, y?: number)
Methods
toString
Returns the current values as a string (" x : y"
)
toString(): string
toMediaConstraint
Returns the current value in a format that can be used as MediaTrackConstraints
toMediaConstraint(): MediaTrackConstraints
isValidVector2
Checks if the provided input is a valid vector2. Returns true
if so.
static isValidVector2(input: any): boolean
IGreenScreenConfig (Interface)
Provides detailed configuration options for GreenScreenStream. maskSettings
can be uses to fine tune the virtual background appearance. (bodyPixMode
can be used to apply premade BodyPix configurations (see GreenScreenStreamBodyPixMode for more details),
while bodyPixConfig
allows you to configure BodyPix as you see fit. If both are provided, bodyPixMode
will be ignored.
IGreenScreenConfig {
maskSettings?: IMaskSettings,
bodyPixMode?: GreenScreenStreamBodyPixMode,
bodyPixConfig?: IBodyPixConfig
}
BodyPixMode (Enum)
Determines which BodyPix Preset GreenStream should use.
Presets Standard
or Precise
are recommended for most use cases.Fast
is meant for really weak clients, is unprecise and causes flickering.Maximum
uses a more complex ML Model and thus causes much more network traffic & gpu + cpu load.\
enum BodyPixMode {
Fast = 0,
Standard = 1,
Precise = 2,
Maximum = 3
}
Preset Details:
Fast
architecture: 'MobileNetV1',
outputStride: 16,
multiplier: 0.5,
quantBytes: 1
Standard
architecture: 'MobileNetV1',
outputStride: 16,
multiplier: 0.75,
quantBytes: 2
Precise
architecture: 'MobileNetV1',
outputStride: 16,
multiplier: 1,
quantBytes: 2
Maximum
architecture: 'ResNet50',
outputStride: 32,
quantBytes: 2
IMaskSettings (Interface)
Description TBA
interface IMaskSettings {
opacity?: number
flipHorizontal?: boolean
maskBlurAmount?: number
foregroundColor?: RGBA
backgroundColor?: RGBA
segmentPerson?: {
flipHorizontal?: boolean
internalResolution?: string
segmentationThreshold?: number
maxDetections?: number
quantBytes?: number
}
};
export interface RGBA {
r: number, g: number, b: number, a: number
}