+function generate_enclosure($url)
+{
+ $supported_content_types = array(
+ "application/ogg",
+ "audio/aac",
+ "audio/mp4",
+ "audio/mpeg",
+ "audio/vorbis",
+ "audio/wav",
+ "audio/webm",
+ "audio/x-midi",
+ "image/gif",
+ "image/jpeg",
+ "video/avi",
+ "video/mp4",
+ "video/mpeg",
+ "video/ogg",
+ );
+
+ $url_info = get_url_info($url);
+
+ $supported = in_array($url_info['content_type'], $supported_content_types);
+ if (!$supported) {
+ error_log("Unsupported enclosure content type \"" . $url_info['content_type'] . "\" for URL: " . $url_info['url']);
+ return '';
+ }
+
+ $dom = new DomDocument();
+ $enc = $dom->createElement('enclosure');
+ $enc->setAttribute('url', $url_info['url']);
+ $enc->setAttribute('length', $url_info['download_content_length']);
+ $enc->setAttribute('type', $url_info['content_type']);
+
+ $dom->appendChild($enc);
+
+ return $dom->saveXML($enc);
+}