Simple Node.js FFMPEG interface

encode.js

var sys = require('sys'),
    child_process = require('child_process');

var encoder = child_process.spawn('ffmpeg',['-i', "video.mkv", '-s', '300x200', '-f', 'avi', '-vcodec', 'mpeg4', 'video.avi']);

var total_time = 0;
var total_data = ''
encoder.stderr.addListener('data', function(data) {
  if (data) {
    total_data += data.toString();
    if (total_data.toString().match(/Duration:\s\d\d:\d\d:\d\d\.\d\d/)) {

       var time = total_data.toString().match(/Duration:\s(\d\d:\d\d:\d\d\.\d\d)/).toString().substring(10,21);
	sys.puts('DATA:' + total_data.toString());
        sys.puts('Time:' + time);
        var seconds = parseInt(time.substr(0,2))*3600 + parseInt(time.substr(3,2))*60 + parseInt(time.substr(6,2));
        total_data = '';
	total_time = seconds;
        sys.puts('sec: ' + seconds);
	
    }
//    sys.puts('>' + data.toString());
//    sys.puts(data.toString().substr(data.toString().length - 6, 5));
    if (data.toString().substr(data.toString().length - 6,5) == '[y/N]') {
	    sys.puts('File already exist, overwriting');
	    encoder.stdin.write('Y', 'ascii');
    }
    if (data.toString().substr(0,5) == 'frame') {
        var time = parseInt(data.toString().match(/time=\s*(\d*)\.\d*/)[0].toString().substr(5));
        sys.puts('Percent done: ' + ((time / total_time) * 100) + '% (' + time + ' of ' + total_time);
    }
  }
    //sys.puts('OUT:'+ data);
});

encoder.stderr.addListener('exit', function(data) {
    sys.puts('Encoding done: ' + data);
});