# VideoOverlay : Video overlay

The videooverlay module provides video overlay function.

videooverlay is a sub object of MediaDecoder.

# Support

The following shows videooverlay module APIs available for each permissions.

# VideoOverlay Object

# videooverlay.clear()

• Returns: {Boolean} Return true if success, otherwise false.

Clear all overlays.

# videooverlay.text(x, y, text, color[, bcolor])

• x {Integer} x position.
• y {Integer} y position.
• text {String} Text which need draw.
• color {Integer} Text color.
• bcolor {Integer} Background color.
• Returns: {Boolean} Return true if success, otherwise false.

Draw a text on overlay.

# videooverlay.point(x, y, color)

• x {Integer} x position.
• y {Integer} y position.
• color {Integer} Point color.
• Returns: {Boolean} Return true if success, otherwise false.

Draw a point on overlay.

# videooverlay.line(x0, y0, x1, y1, color[, width])

• x0 {Integer} x0 position.
• y0 {Integer} y0 position.
• x1 {Integer} x1 position.
• y1 {Integer} y1 position.
• color {Integer} Line color.
• width {Integer} Line width.
• Returns: {Boolean} Return true if success, otherwise false.

Draw a line on overlay.

# videooverlay.rect(x0, y0, x1, y1, color[, width[, r[, fill]]])

• x0 {Integer} x position of upper left corner.
• y0 {Integer} y position of upper left corner.
• x1 {Integer} x position of lower right corner.
• y1 {Integer} y position of lower right corner.
• color {Integer} Line color.
• width {Integer} Line width.
• r {Integer} The radius of fillet.
• fill {Boolean} Does fill rectangle?
• Returns: {Boolean} Return true if success, otherwise false.

Draw a rectangle on overlay.

# videooverlay.circle(x, y, r, color[, width[, fill]])

• x {Integer} x position of center.
• y {Integer} y position of center.
• r Integer Line color.
• color {Integer} Line color.
• width {Integer} Line width.
• fill {Boolean} Does fill circle?
• Returns: {Boolean} Return true if success, otherwise false.

Draw a circle on overlay.

# videooverlay.font(font)

• font {Integer} Font size.
• Returns: {Boolean} Return true if success, otherwise false.

font is a integer, can be:

# videooverlay.draw(buf)

• buf {Buffer} Buffer which need to be draw.
• Returns: {Boolean} Return true if success, otherwise false.

Draw all overlays to specified buffer.

# Example

This example show how to draw something on the video overlay.

#!/bin/javascript

var MediaDecoder = require('mediadecoder');
var iosched = require('iosched');

var netcam = new MediaDecoder().open('rtsp://admin:admin@10.4.0.12');

netcam.destVideoFormat({width: 640, height: 360, fps: 1, pixelFormat: MediaDecoder.PIX_FMT_RGB24, disable: false});
netcam.destAudioFormat({disable: true});
netcam.previewFormat({enable: true, fb: 0, fps: 25});

var quited = false;

var ol = netcam.overlay();

ol.font(ol.F8X12);
ol.text(40, 20, 'EdgerOS', MediaDecoder.C_WHITE);
ol.point(40, 40, MediaDecoder.C_RED);
ol.line(40, 50, 80, 50, MediaDecoder.C_RED, 4);
ol.rect(40, 60, 80, 100, MediaDecoder.C_RED, 8, 2, true);
ol.circle(70, 140, 30, MediaDecoder.C_RED, 2);

netcam.on('video', (video) => {
});

netcam.on('eof', () => {
  quited = true;
});

netcam.start();

while (!quited) {
  iosched.poll(); // Event poll.
}

netcam.close();