Streaming an mp4 through a php file progressively

Question

I'm working on a more secure streaming method for our video player. Because each file requires special token authentication and also only allows each token to be loaded once, I'm running MP4 through a php container. This works perfectly inside a HTML5 video tag and prevents users from easily downloading the source.

I'm adapting some code from here

<?php
include('...'); //include site functions

/*
   Here I connect to the database, and retrieve the
   location of the video which is returned as
   $video = "http://domain.tld/folder/file.mp4"

   This has been removed for this SO example.
*/

$file = $video;
$fp = @fopen($file, 'rb');

$head = array_change_key_case(get_headers($file, TRUE));
$size = $head['content-length'];


//$size   = filesize($file); // File size
$length = $size;           // Content length
$start  = 0;               // Start byte
$end    = $size - 1;       // End byte
header('Content-type: video/mp4');
//header("Accept-Ranges: 0-$length");
header("Accept-Ranges: bytes");
if (isset($_SERVER['HTTP_RANGE'])) {
    $c_start = $start;
    $c_end   = $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 $start-$end/$size");
        exit;
    }
    if ($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 : $c_end;
    if ($c_start > $c_end || $c_start > $size - 1 || $c_end >= $size) {
        header('HTTP/1.1 416 Requested Range Not Satisfiable');
        header("Content-Range: bytes $start-$end/$size");
        exit;
    }
    $start  = $c_start;
    $end    = $c_end;
    $length = $end - $start + 1;
    fseek($fp, $start);
    header('HTTP/1.1 206 Partial Content');
}
header("Content-Range: bytes $start-$end/$size");
header("Content-Length: ".$length);
$buffer = 1024 * 8;
while(!feof($fp) && ($p = ftell($fp)) <= $end) {
    if ($p + $buffer > $end) {
        $buffer = $end - $p + 1;
    }
    set_time_limit(0);
    echo fread($fp, $buffer);
    flush();
}
fclose($fp);
exit();
?>

Problems now arise as I'd like to be able to seek into the video. Skipping to an area in the video which has not been loaded crashes the <video> tag (and chrome).

I'd assume that since the HTML5 player is seeking in seconds and the PHP is loading in bytes, that this cannot be done. Which is why I'm asking here.

What can I do (if anything) to allow progressive streaming?
Is there a more appropriate container format I could use which would serve the same purpose?

Answer 1

In addition to what dlopez said, I recommend to use 3rd-party solution for progressive download with seeking capabilities (AKA pseudo-streaming). You may take a look at the PD solutions listed in Wikipedia: https://en.wikipedia.org/wiki/Progressive_download

Most of them can also prevent video hotlinking protection as well.