<?php
if ($_SERVER['REQUEST_METHOD'] != 'GET') {
    die("Expected a GET request!\n");
}

$video_file = "video1.ogg";
if (isset($_REQUEST['audioonly']))
  $video_file = "audio1.ogg";
if (isset($_REQUEST['gif']))
  $video_file = "disco.gif";

if(!file_exists($video_file) || !is_file($video_file)) {
    die("File " . $video_file . "doesn't exist");
}

$video_size = filesize($video_file);
$send_start = 0;
$send_end   = $video_size;

// If the request didn't specify a range, send the whole file.
if (!isset($_SERVER['HTTP_RANGE'])) {
    if (isset($_REQUEST['gif']))
      header("Content-Type: image/gif");
    else
      header("Content-Type: application/ogg");
    header("Accept-Ranges: bytes");
    header("Access-Control-Allow-Origin: *");
    header("Content-Length: " . $video_size);
    if (isset($_REQUEST['duration']))
        header("X-Content-Duration: " . $_REQUEST['duration']);
    send_file($video_file, $send_start, $send_end);
    exit;
}

$range = stristr(trim($_SERVER['HTTP_RANGE']),'bytes=');
$range=substr($range,6);
get_request_range($range, $video_size, $send_start, $send_end);
    
header("HTTP/1.1 206 Partial content");
if (isset($_REQUEST['gif']))
  header("Content-Type: image/gif");
else
  header("Content-Type: application/ogg");
header("Accept-Ranges: bytes");
header("Access-Control-Allow-Origin: *");
header("Content-Length: " . ($send_end - $send_start + 1));
header("Content-Range: bytes $send_start-$send_end/$video_size");
if (isset($_REQUEST['duration']))
    header("X-Content-Duration: " . $_REQUEST['duration']);
send_file($video_file, $send_start, $send_end);

function get_request_range($range, $filesize, &$first, &$last){
  /*
   * The following byte serving code is (C) 2004 Razvan Florian. You may find the
   * latest version at http://www.coneural.org/florian/papers/04_byteserving.php
   */
  /*
  Sets the first and last bytes of a range, given a range expressed as a string 
  and the size of the file.

  If the end of the range is not specified, or the end of the range is greater 
  than the length of the file, $last is set as the end of the file.

  If the begining of the range is not specified, the meaning of the value after 
  the dash is "get the last n bytes of the file".

  If $first is greater than $last, the range is not satisfiable, and we should 
  return a response with a status of 416 (Requested range not satisfiable).

  Examples:
  $range='0-499', $filesize=1000 => $first=0, $last=499 .
  $range='500-', $filesize=1000 => $first=500, $last=999 .
  $range='500-1200', $filesize=1000 => $first=500, $last=999 .
  $range='-200', $filesize=1000 => $first=800, $last=999 .

  */
  $dash=strpos($range,'-');
  $first=trim(substr($range,0,$dash));
  $last=trim(substr($range,$dash+1));
  if ($first=='') {
    //suffix byte range: gets last n bytes
    $suffix=$last;
    $last=$filesize-1;
    $first=$filesize-$suffix;
    if($first<0) $first=0;
  } else {
    if ($last=='' || $last>$filesize-1) $last=$filesize-1;
  }
  if($first>$last){
    //unsatisfiable range
    header("Status: 416 Requested range not satisfiable");
    header("Content-Range: */$filesize");
    exit;
  }
}

 
// Sends the specified byte range from the file.
function send_file($filename, $start, $end) {
    flush(); // make sure headers are sent asap.

    $bytes_sent = 0;
    $bytes_remaining = $end - $start + 1;

    $rate  = isset($_REQUEST['rate']) ? $_REQUEST['rate'] : 9999999;

    $do_rate2 = isset($_REQUEST['rate2']);
    $rate2 = $_REQUEST['rate2'];
    $rate2_at = $_REQUEST['rate2at'] - $start; // no default 

    $do_stall = isset($_REQUEST['stallat']);
    $stall_at = $_REQUEST['stallat'] - $start; // no default
    $stall_time = isset($_REQUEST['stallfor']) ? $_REQUEST['stallfor'] : 7;
 
    // Open the file, and seek to our start point
    $file = fopen($filename, "rb");    
    fseek($file, $start);

    // loop over data, sending a burst every 100ms.
    while (!feof($file) && $bytes_remaining) {
        $burst_size = round($rate * 1024 / 8 / 10); // kbps to Bps, 10x per second
        // Can't send more than we have!
        if ($burst_size > $bytes_remaining)
            $burst_size = $bytes_remaining;
        // If burst includes the stall point or rate2 point, burst only to that point.
        if ($do_stall &&
            $stall_at >= $bytes_sent &&
            $stall_at <= $bytes_sent + $burst_size)
            $burst_size = $stall_at - $bytes_sent;
        if ($do_rate2 &&
            $rate2_at >= $bytes_sent &&
            $rate2_at <= $bytes_sent + $burst_size)
            $burst_size = $rate2_at - $bytes_sent;
        
        // Send data
        print fread($file, $burst_size);    
        flush();
        ob_flush();

        $bytes_remaining -= $burst_size;
        $bytes_sent += $burst_size;

        if ($do_rate2 && $rate2_at == $bytes_sent) {
            $rate = $rate2;
            $do_rate2 = 0;
        }

        if ($do_stall && $stall_at == $bytes_sent) {
            sleep($stall_time);
            $do_stall = 0;
        } else {
            usleep(100000); // 100ms
        }
    }    
    fclose($file);
}

?>