var page = require("webpage").create();
var width = 1280;
var height = 720;
page.viewportSize = { width: width, height: height };

var system = require('system');	

if (system.args.length < 3) {
    console.log('please supply address URL and output name');
    phantom.exit();
}

var address = system.args[1];
var output = system.args[2];

page.open(address, function () {
    // as per https://github.com/ariya/phantomjs/issues/10619#issuecomment-33248657
    page.evaluate(function(w, h) {
        document.body.style.width = w + "px";
        document.body.style.height = h + "px";
    }, width, height);
    page.clipRect = {top: 0, left: 0, width: width, height: height};

    setInterval(function () {
        page.render(output, { format: "png" });
    }, 250);
});

// https://mindthecode.com/blog/recording-a-website-with-phantomjs-and-ffmpeg/
// https://trac.ffmpeg.org/wiki/EncodingForStreamingSites
// phantomjs ../runner.js |  ffmpeg -y -c:v png -f image2pipe -r 10 -t 5  -i - -f v4l2 -video_size 640x360 -i /dev/video0 -filter_complex "[0:v][1:v]overlay=640:0,format=yuv420p[v]" -map "[v]" -c:v libx264 -pix_fmt yuv420p -movflags +faststart dragon.mp4