// Initialize autoloader
require_once __DIR__ . '/vendor/autoload.php';

// Import classes
use GravityMedia\Ghostscript\Ghostscript;
use Symfony\Component\Process\Process;

// Define input and output files
$inputFile = '/path/to/input/file.pdf';
$outputFile = '/path/to/output/file.pdf';

// Create Ghostscript object
$ghostscript = new Ghostscript([
    'quiet' => false
]);

// Create and configure the device
$device = $ghostscript->createPdfDevice($outputFile);
$device->setCompatibilityLevel(1.4);

// Create process
$process = $device->createProcess($inputFile);

// Print the command line
print '$ ' . $process->getCommandLine() . PHP_EOL;

// Run process
$process->run(function ($type, $buffer) {
    if ($type === Process::ERR) {
        throw new \RuntimeException($buffer);
    }

    print $buffer;
});