public static function getVideoIDList($youtubeURL, $optionalparameters, &$channelid, &$datalink)
 {
     $optionalparameters_arr = explode(',', $optionalparameters);
     $videolist = array();
     $base_url = 'https://www.googleapis.com/youtube/v3';
     $api_key = YouTubeGalleryMisc::getSettingValue('youtube_api_key');
     if ($api_key == '') {
         return $videolist;
     }
     $spq = implode('&', $optionalparameters_arr);
     $channelid = VideoSource_YoutubeChannel::extractID($youtubeURL);
     if ($channelid == '') {
         return $videolist;
     }
     //user id not found
     $part = 'id,snippet';
     $spq = str_replace('max-results', 'maxResults', $spq);
     $datalink = $base_url . '/search?channelId=' . $channelid . '&part=' . $part . '&key=' . $api_key . ($spq != '' ? '&' . $spq : '');
     $opt = "";
     $count = YouTubeGalleryMisc::getMaxResults($spq, $opt);
     if ($count < 1) {
         $maxResults = 1;
     } elseif ($count > 50) {
         $maxResults = 50;
     } else {
         $maxResults = $count;
     }
     $videos_found = 0;
     $nextPageToken = '';
     while ($videos_found < $count) {
         $newspq = str_replace($opt, 'maxResults=' . $maxResults, $spq);
         $url = $base_url . '/search?channelId=' . $channelid . '&part=' . $part . '&key=' . $api_key . ($newspq != '' ? '&' . $newspq : '');
         if ($nextPageToken != '') {
             $url .= '&pageToken=' . $nextPageToken;
         }
         $htmlcode = YouTubeGalleryMisc::getURLData($url);
         if ($htmlcode == '') {
             return $videolist;
         }
         $j = json_decode($htmlcode);
         if (!$j) {
             return 'Connection Error';
         }
         $nextPageToken = $j->nextPageToken;
         $pageinfo = $j->pageInfo;
         if ($pageinfo->totalResults < $count) {
             $count = $pageinfo->totalResults;
         }
         $items = $j->items;
         if (count($items) < $maxResults) {
             $maxResults = count($items);
         }
         foreach ($items as $item) {
             if ($item->kind == 'youtube#searchResult') {
                 $idKind = $item->id->kind;
                 if ($idKind == 'youtube#video') {
                     $videoId = $item->id->videoId;
                     $videolist[] = 'https://www.youtube.com/watch?v=' . $videoId;
                 }
             }
         }
         $videos_found += $maxResults;
         if ($count - $videos_found < 50) {
             $maxResults = $count - $videos_found;
         }
     }
     return $videolist;
 }