Support HTTP Header Range, mp4, php.php/mp4.mp4

gistfile1.php

<?php
# Nginx don't have PATH_INFO
if (!isset($_SERVER['PATH_INFO'])) {
	$_SERVER['PATH_INFO'] = substr($_SERVER["ORIG_SCRIPT_FILENAME"], strlen($_SERVER["SCRIPT_FILENAME"]));
}

$request = substr($_SERVER['PATH_INFO'], 1);
$file = $request;
$fp = @fopen($file, 'rb');

$size   = filesize($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-$length");
if (isset($_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();
?>

Everything works fine but for some reason I don't know, when I start playing a video and then click on a link on my page or use the browser's back button, the browser freezes and waits a while ( variable ) before following the link.

The profiler indicates that the requested page change is in pending status.
If I position the video cursor further away, the browser unlocks instantly and follows the link I clicked.

And finally if I reload that page, the issue doesn't appears anymore. Seems that chrome have cached the video.

Any idea ?

EDIT
it seems that problem occurs only with chrome..
While debugging script, I saw that value in "Content-range" header always empty.
That's involve that chrome tries to fully load video and not partially. I think this is that causing the issue.

Any idea ?

EDIT2
And of course I changed Accept-Ranges: 0-$length to Accept-Ranges: bytes

Same here... some ideas?

Thanks dude!
I had to implement ranging for video downloading for iOS video player purposes (Flutter) and it works!
I adopted it for Slim framework of course :)