Chrome can't fast forward, Firefox can. Display MP4 file with PHP

Question

I am using video/mp4 and I can't skip seconds. Kind of like Chrome doesn't know the file size.

$local_file

This var contains a relative link to the file. The link is correct.

header('Content-Description: File Transfer');
header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename=dynamicMediaContent');
header('Expires: 0');
header('Cache-Control: must-revalidate');
header('Pragma: public');
header("Content-Type: $format");
header("Accept-Ranges: 0-".filesize($local_file));
header("Content-Length: ".filesize($local_file));
readfile($local_file);

Firefox is able to fast forward.

Chrome also can't read the duration of the video. Firefox can.

Answer 1

I have found the final solution. The script is a bit long, but it's worth it.

It definitely works. It's tested.

<?php
//your file here
//mp3 also works
$file = 'filename.mp4';

$fp = @fopen($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");
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();
?>