Php replace img tab to amp-img

Hi,

This code can replace img tag to amp-img for AMP project cache google:

$content = ' <img src="thanhansoft.jpg"/>this <img alt="" src="fdolacom.jpg" style="width: 700px; height: 473px;" /> sds <img src="fdola.png"/> is something with an <img src="test.png"/> in it.';
$content = preg_replace('/<img[^>]+src="([^"]+)"[^>]+>/i', '<amp-img>$1</amp-img>', $content);
echo '<pre>';
print_r($content);
echo '</pre>';