public function getCopyright()
    {
        if ($this->copyright === null) {
            $match = [];
            preg_match(self::$REGEX_COPYRIGHT, $this->output, $match);
            $this->copyright = array_key_exists(2, $match) ? trim($match[2]) : '';
        }

        return $this->copyright;
    }
public function getCopyright()
    {
        if ($this->copyright === null) {
            $match = [];
            preg_match(self::$REGEX_COPYRIGHT, $this->output, $match);
            $this->copyright = array_key_exists(2, $match) ? trim($match[2]) : '';
        }

        return $this->copyright;
    }
public function getCopyright ( ) { if ( $ this -> copyright === null ) { $ match = [ ] ; preg_match ( self :: $ REGEX_COPYRIGHT , $ this -> output , $ match ) ; $ this -> copyright = array_key_exists ( 2 , $ match ) ? trim ( $ match [ 2 ] ) : '' ; } return $ this -> copyright ; }
Return the copyright field from the movie or audio file.

@return string
Return the copyright field from the movie or audio file .