HTML5 video and partial range HTTP requests

html, http, video

Solution

I know this is an old question, but if it helps you can try the following "Model" that we use in our code base.

class Model_DownloadableFile {
private $full_path;

function __construct($full_path) {
    $this->full_path = $full_path;
}

public function get_full_path() {
    return $this->full_path;
}

// Function borrowed from (been cleaned up and modified slightly): http://stackoverflow.com/questions/157318/resumable-downloads-when-using-php-to-send-the-file/4451376#4451376
// Allows for resuming paused downloads etc
public function download_file_in_browser() {
    // Avoid sending unexpected errors to the client - we should be serving a file,
    // we don't want to corrupt the data we send
    @error_reporting(0);

    // Make sure the files exists, otherwise we are wasting our time
    if (!file_exists($this->full_path)) {
        header('HTTP/1.1 404 Not Found');
        exit;
    }

    // Get the 'Range' header if one was sent
    if (isset($_SERVER['HTTP_RANGE'])) {
        $range = $_SERVER['HTTP_RANGE']; // IIS/Some Apache versions
    } else if ($apache = apache_request_headers()) { // Try Apache again
        $headers = array();
        foreach ($apache as $header => $val) {
            $headers[strtolower($header)] = $val;
        }
        if (isset($headers['range'])) {
            $range = $headers['range'];
        } else {
            $range = false; // We can't get the header/there isn't one set
        }
    } else {
        $range = false; // We can't get the header/there isn't one set
    }

    // Get the data range requested (if any)
    $filesize = filesize($this->full_path);
    $length = $filesize;
    if ($range) {
        $partial = true;
        list($param, $range) = explode('=', $range);
        if (strtolower(trim($param)) != 'bytes') { // Bad request - range unit is not 'bytes'
            header("HTTP/1.1 400 Invalid Request");
            exit;
        }
        $range = explode(',', $range);
        $range = explode('-', $range[0]); // We only deal with the first requested range
        if (count($range) != 2) { // Bad request - 'bytes' parameter is not valid
            header("HTTP/1.1 400 Invalid Request");
            exit;
        }
        if ($range[0] === '') { // First number missing, return last $range[1] bytes
            $end = $filesize - 1;
            $start = $end - intval($range[0]);
        } else if ($range[1] === '') { // Second number missing, return from byte $range[0] to end
            $start = intval($range[0]);
            $end = $filesize - 1;
        } else { // Both numbers present, return specific range
            $start = intval($range[0]);
            $end = intval($range[1]);
            if ($end >= $filesize || (!$start && (!$end || $end == ($filesize - 1)))) {
                $partial = false;
            } // Invalid range/whole file specified, return whole file
        }
        $length = $end - $start + 1;
    } else {
        $partial = false; // No range requested
    }

    // Determine the content type
    $finfo = finfo_open(FILEINFO_MIME_TYPE);
    $contenttype = finfo_file($finfo, $this->full_path);
    finfo_close($finfo);

    // Send standard headers
    header("Content-Type: $contenttype");
    header("Content-Length: $length");
    header('Content-Disposition: attachment; filename="' . basename($this->full_path) . '"');
    header('Accept-Ranges: bytes');

    // if requested, send extra headers and part of file...
    if ($partial) {
        header('HTTP/1.1 206 Partial Content');
        header("Content-Range: bytes $start-$end/$filesize");
        if (!$fp = fopen($this->full_path, 'r')) { // Error out if we can't read the file
            header("HTTP/1.1 500 Internal Server Error");
            exit;
        }
        if ($start) {
            fseek($fp, $start);
        }
        while ($length) { // Read in blocks of 8KB so we don't chew up memory on the server
            $read = ($length > 8192) ? 8192 : $length;
            $length -= $read;
            print(fread($fp, $read));
        }
        fclose($fp);
    } else {
        readfile($this->full_path); // ...otherwise just send the whole file
    }

    // Exit here to avoid accidentally sending extra content on the end of the file
    exit;
}
}

You then use it like this:

(new Model_DownloadableFile('FULL/PATH/TO/FILE'))->download_file_in_browser();

It will deal with sending part of the file or the full file etc and works well for us in this and lots of other situations. Hope it helps.

Problem

Original source