Superficial GStreamer binding

This is a superficial binding of GStreamer to Node.js. It does not attempt at being a complete binding, and will hopefully one day be replaced by (or implemented with) node-gir.

const gstreamer = require('gstreamer-superficial');
const pipeline = new gstreamer.Pipeline(`videotestsrc ! textoverlay name=text
	! autovideosink`);
	
pipeline.play();

Then, you can find an element within the pipeline, and set its properties:

const target = pipeline.findChild('text');

target.text = 'Hello';
Object.assign(target.text, {
	text: 'Hello', 
	'font-desc': 'Helvetica 32',
})

(see also examples/basic-pipeline.js)

Pipeline also knows .stop(), .pause() and .pollBus(), the elements returned by .findChild() getting and setting all properties the real GObjects do, appsinks also support .pull() (see below).

There is a simple .seek(position, flags) function. Normally you should pass 1 for flags (GST_SEEK_FLAG_FLUSH). See Flags and Seek Docs.

You can query the pipeline's duration and current position with .getDuration() and .getPosition() (both might return -1). All time position values are in Seconds.

(see also examples/seek.js)

You can asynchronously handle bus messages using Pipeline.pollBus(callback):

pipeline.pollBus(msg => {
	console.log(msg);
});

(see also examples/bus.js)

You can feast off GStreamer's appsink to handle binary data. .pull starts a background work queue and calls your callback whenever a buffer is (or caps are) available:

const appsink = pipeline.findChild('sink');

function onData(buf, caps) {
	if (caps) {
		console.log('CAPS', caps);
	}
	if (buf) {
		console.log('BUFFER size', buf.length);
		appsink.pull(onData);
	}

	// !buf probably means EOS
}

appsink.pull(onData);

(see examples/appsink.js)

should be working as implemented in examples/streaming/
run server.js (requires express) and point your browser to http://localhost:8001. (Tested only with Chromium). This handles retaining the streamheader to feed first to every newly connected client.

gstreamer-superficial was originally written by Daniel Turing, and has received contributions from various individuals as seen on github and in package.json.

• libgstreamer-plugins-base1.0-dev
• libgstreamer1.0-dev
• nan