PHP script for controlling mplayer to automatically take screenshots

screenshotter.php

<?php
define('DS', DIRECTORY_SEPARATOR);
$ssCount = 250;

$cmdMplayer = "e:\downloads\mplayer\mplayer\mplayer.exe";
$argsInfo = " -vo null -nosound -frames 0 -identify";
$argsCapture = " -quiet -nosound -vo jpeg:quality=90 -vf framestep=i{framestep} -fps 360 -lavdopts threads=4";

if($_SERVER['argc'] > 1)
{
	array_shift($_SERVER['argv']);
	foreach($_SERVER['argv'] AS $file)
	{
		if(file_exists($file) && is_file($file))
		{
			$screenshotDir = dirname($file).DS.'screenshots'.DS.basename($file).DS;
			if((!is_dir($screenshotDir) && !mkdir($screenshotDir, null, true)) || !is_writable($screenshotDir))
			{
				echo "Unable to write/create to screenshot directory ({$screenshotDir})";
				break;
			}
			chdir($screenshotDir);

			$infoOutput = shell_exec("{$cmdMplayer}{$argsInfo} \"{$file}\"");

			// discover file length
			$matcher = '/ID_LENGTH=(\d+\.\d+)$/m';
			$matches = array();

			preg_match_all($matcher, $infoOutput, $matches);

			$fileLength = (!empty($matches[1][0])) ? floatval($matches[1][0]) : 0;
			if(!$fileLength)
			{
				echo "Unable to determine file length ({$file})";
				break;
			}

			// discover frame rate
			$matcher = '/ID_VIDEO_FPS=(\d+\.\d+)$/m';
			$matches = array();

			preg_match_all($matcher, $infoOutput, $matches);

			$frameRate = (!empty($matches[1][0])) ? floatval($matches[1][0]) : 0;
			if(!$frameRate)
			{
				echo "Unable to determine file frame rate ({$file})";
				break;
			}

			$framestep = floor(($fileLength * $frameRate) / $ssCount);
			$args = str_replace(array('{outdir}', '{framestep}'), array($screenshotDir, $framestep), $argsCapture);

			//var_dump("{$cmdMplayer}{$args} \"".escapeshellarg($file)."\"");

			//var_dump("{$cmdMplayer}{$args} \"{$file}\"");
			system("{$cmdMplayer}{$args} \"{$file}\"");
		}
	}
}