Stream video via PHP Zend Framework

public function downloadAction()
    {
        $this->_helper->viewRenderer->setNoRender();
        $this->_helper->layout->disableLayout();
        
        $videoFolder = realpath(APPLICATION_PATH . "/videos");
        
        //This is example video - it can be from a param
        $video = $videoFolder . "/zyploiifb5cja02a.mp4";
        
        $fileBaseName = basename($video);
        $fileParts = explode(".", $fileBaseName);
        $ext = $fileParts[count($fileParts)-1];
        
        switch ($ext)
        {
            case 'mp4':
                $this->getResponse()->setHeader('Content-Type', 'video/mp4');
                break;
            case 'flv':
                $this->getResponse()->setHeader('Content-Type', 'video/flv');
        }
        
        $fp = fopen($video, 'rb');
        $size = filesize($video);
        $length = $size;
        
        $chunksize = 1 * (1024 * 1024);
        
        if(empty($_SERVER['HTTP_RANGE']))
        {
            $this->getResponse()->setHeader('Content-Length', $length);
            $this->getResponse()->sendHeaders();
            
            while (!feof($fp))
            {
                echo fread($fp, $chunksize);
                ob_flush(); 
                flush();
            }
            fclose($fp);
            exit;
        }
        
        /*
         * FROM http://mobiforge.com/developing/story/content-delivery-mobile-devices
         */
        
        $start = 0;
        $end = $length - 1;
        
        $this->getResponse()->setHeader('Accept-Ranges', '0-'.$length);
        $this->getResponse()->setHttpResponseCode(206);
        
        $c_start = $start;
        $c_end   = $end;
        
        list(, $range) = explode('=', $_SERVER['HTTP_RANGE'], 2);
        
        if ($range == '-')
        {
            $c_start = $size - substr($range, 1);      
        }
        else 
        {
            $range  = explode('-', $range);
            $c_start = $range[0];
            $c_end   = (isset($range[1]) && is_numeric($range[1])) ? $range[1] : $size;
        }
        
        $c_end = ($c_end > $end) ? $end : $c_end;
        $start  = $c_start;
        $end    = $c_end;
        $length = $end - $start + 1;
        fseek($fp, $start);
        $this->getResponse()->setHeader('Content-Range', "bytes $start-$end/$size");
        $this->getResponse()->setHeader('Content-Length', $length);
        
        $this->getResponse()->sendHeaders();
        
        $bytesSent = 0;
         
        while(!feof($fp) && ($p = ftell($fp)) <= $end)
        {
            if ($p + $chunksize > $end)
            {
                $chunksize = $end - $p + 1;    
            }
            set_time_limit(0);
            echo fread($fp, $chunksize);
            $bytesSent += $chunksize;
            ob_flush();
            flush();
        }
        
        fclose($fp);        
        die;
    }  

转：https://gist.github.com/1602689