<?php
/**
 * VFM - Veno File Manager 2 - class used to stream vids
 */

/**
 * VideoStream class
 *
 * PHP version >= 5.3
 *
 * @category PHP
 * @author   Rana
 * @link     https://gist.github.com/ranacseruet/9826293
 */
class VideoStream
{
    private $path = "";
    private $stream = "";
    private $buffer = 102400;
    private $start  = -1;
    private $end    = -1;
    private $size   = 0;
    private $videoFormats = array(
        "mp4"=>"video/mp4", 
        "webm"=>"video/webm", 
        "ogg"=>"video/ogg", 
        "ogv"=>"video/ogg",
        );
    /**
     * Construct.
     */    
    function __construct($filePath) 
    {
        $this->path = $filePath;
    }
     
    /**
     * Open stream
     */
    private function open()
    {
        if (!($this->stream = fopen($this->path, 'rb'))) {
            die('Could not open stream for reading');
        }    
    }
     
    /**
     * Set proper header to serve the video content.
     */
    private function setHeader()
    {
        ob_get_clean();
        header("Content-Type: video/mp4");
        header("Content-Type: ".($this->videoFormats[strtolower(pathinfo($this->path, PATHINFO_EXTENSION))]));
        header("Cache-Control: max-age=2592000, public");
        header("Expires: ".gmdate('D, d M Y H:i:s', time()+2592000) . ' GMT');
        header("Last-Modified: ".gmdate('D, d M Y H:i:s', @filemtime($this->path)) . ' GMT');
        $this->start = 0;
        $this->size  = filesize($this->path);
        $this->end   = $this->size - 1;
        header("Accept-Ranges: 0-".$this->end);
         
        if (isset($_SERVER['HTTP_RANGE'])) {
  
            $c_start = $this->start;
            $c_end = $this->end;
 
            list(, $range) = explode('=', $_SERVER['HTTP_RANGE'], 2);
            if (strpos($range, ',') !== false) {
                header('HTTP/1.1 416 Requested Range Not Satisfiable');
                header("Content-Range: bytes $this->start-$this->end/$this->size");
                exit;
            }
            if ($range == '-') {
                $c_start = $this->size - substr($range, 1);
            } else {
                $range = explode('-', $range);
                $c_start = $range[0];
                 
                $c_end = (isset($range[1]) && is_numeric($range[1])) ? $range[1] : $c_end;
            }
            $c_end = ($c_end > $this->end) ? $this->end : $c_end;
            if ($c_start > $c_end || $c_start > $this->size - 1 || $c_end >= $this->size) {
                header('HTTP/1.1 416 Requested Range Not Satisfiable');
                header("Content-Range: bytes $this->start-$this->end/$this->size");
                exit;
            }
            $this->start = $c_start;
            $this->end = $c_end;
            $length = $this->end - $this->start + 1;
            fseek($this->stream, $this->start);
            header('HTTP/1.1 206 Partial Content');
            header("Content-Length: ".$length);
            header("Content-Range: bytes $this->start-$this->end/".$this->size);
        } else {
            header("Content-Length: ".$this->size);
        }
    }

    /**
     * Close curretly opened stream
     */
    private function end()
    {
        fclose($this->stream);
        exit;
    }
     
    /**
     * Perform the streaming of calculated range
     */
    private function stream()
    {
        $i = $this->start;
        set_time_limit(0);
        while (!feof($this->stream) && $i <= $this->end) {
            $bytesToRead = $this->buffer;
            if (($i+$bytesToRead) > $this->end) {
                $bytesToRead = $this->end - $i + 1;
            }
            $data = fread($this->stream, $bytesToRead);
            echo $data;
            flush();
            $i += $bytesToRead;
        }
    }
     
    /**
     * Start streaming video content
     */
    function start()
    {
        $this->open();
        $this->setHeader();
        $this->stream();
        $this->end();
    }
}
