public function getPixelFormat()
    {
        if ($this->pixelFormat === null) {
            $match = [];
            preg_match(self::$REGEX_PIXEL_FORMAT, $this->output, $match);
            $this->pixelFormat = array_key_exists(1, $match) ? trim($match[1]) : '';
        }

        return $this->pixelFormat;
    }
public function getPixelFormat()
    {
        if ($this->pixelFormat === null) {
            $match = [];
            preg_match(self::$REGEX_PIXEL_FORMAT, $this->output, $match);
            $this->pixelFormat = array_key_exists(1, $match) ? trim($match[1]) : '';
        }

        return $this->pixelFormat;
    }
public function getPixelFormat ( ) { if ( $ this -> pixelFormat === null ) { $ match = [ ] ; preg_match ( self :: $ REGEX_PIXEL_FORMAT , $ this -> output , $ match ) ; $ this -> pixelFormat = array_key_exists ( 1 , $ match ) ? trim ( $ match [ 1 ] ) : '' ; } return $ this -> pixelFormat ; }
Return the pixel format of the movie.

@return string
Return the pixel format of the movie .