为什么我不能在文档根目录之外投射由PHP提供的MP4文件？ [英] Why can't I cast an MP4 file served by PHP from outside of the document root?

问题描述

好吧，我放弃...发生了非常奇怪的事情，经过数天的混乱，我不得不寻求帮助。我有一个PHP脚本，可从文档根目录外部提供MP4文件。该脚本非常有用，除了一个非常重要的细节（至少对我而言）：它不会给我选择投射内容的选项。在同一台服务器上，当我访问位于文档根目录中的MP4文件时，将加载页面，然后单击Chrome视频播放器右下角的三个点，即可选择下载或投射到我的Chromecast。使用我的脚本，我只能选择下载，而我真的需要CAST！我已经做了很多调整，以至于任何一个方法的标题输出都几乎是相同的。这是我的代码...

Ok, I give up... Something very strange is going on and, after days of messing with this, I have to ask for help. I have a PHP script that serves an MP4 file from outside of the document root. This script works great, except for one very important (to me at least) detail: it will not give me the option to cast the content. On the same server, when I access an MP4 file that IS inside the document root, I load the page and when I click the three dots in the bottom right corner of the Chrome video player, I have the option to Download or Cast to my Chromecast. Using my script, I only have the option to Download, and I REALLLLY need to CAST! I have tweaked this so much that the headers output from either method are all but identical. Here is my code...

<?php
$file=$_GET['file'];

//validate
if($file=="." || $file==".."){$file="";}

$mediaRoot="../../../hostMedia";
$file=$mediaRoot . DIRECTORY_SEPARATOR . $file;
$file=str_replace('\\',"/",$file);

$filesize = filesize($file);

$offset = 0;
$length = $filesize;

// find the requested range
preg_match('/bytes=(\d+)-(\d+)?/', $_SERVER['HTTP_RANGE'], $matches);

$offset = intval($matches[1]);

$length = (($matches[2]) ? intval($matches[2]) : $filesize) - $offset;

// output the right headers for partial content
header('HTTP/1.1 206 Partial Content');
header('Content-Range: bytes ' . $offset . '-' . ($offset + $length-1) . '/' . $filesize);
header('Content-Type: video/mp4');
header('Content-Length: ' . $filesize);
header('Accept-Ranges: bytes');
header('Cache-Control: max-age=0');

// open file for reading
$file = fopen($file, 'r');

// seek to the requested offset, this is 0 if it's not a partial content request
fseek($file, $offset);

// populate $data with all except the last byte of the file
$numBytes=($filesize-1);
$dataLen=0;
while($dataLen<$numBytes){
    $lenGrab=($numBytes-$dataLen);
    if($lenGrab>(1024*2700)){$lenGrab=(1024*2700);}
    $data=fread($file, $lenGrab);
    print($data);
    $dataLen+=strlen($data);
}

// close file
fclose($file);
?>

一千个谢谢给解决这个问题的人！

A thousand "thank-you"s to whoever solves this one!

更新

好吧，我接受@Brian Heward的建议，花了无数小时来确保标题是绝对相同！！！我非常确定它会起作用，但是，遗憾的是，它仍然无法让我选择投射。这是我更新的PHP ...

Ok, taking @Brian Heward's advice, I have spent countless hours making sure that the headers are ABSOLUTELY IDENTICAL!!! I was so sure it would work, but alas, it still fails to give me the option to cast. Here is my updated PHP...

<?php
session_start();

$accessCode=$_SESSION['accessCode'];
$file=$_GET['file'];

//handle injection
if($file=="." || $file==".."){$file="";}

if($accessCode=="blahblahblah8"){

    $mediaRoot="../../../hostMedia";
    $file=$mediaRoot . DIRECTORY_SEPARATOR . $file;
    $file=str_replace('\\',"/",$file);

    $filesize = filesize($file);

    $offset = 0;
    $length = $filesize;
    $lastMod=filemtime($file);

    if ( isset($_SERVER['HTTP_RANGE']) ) {
        // if the HTTP_RANGE header is set we're dealing with partial content
        $partialContent = true;
        // find the requested range
        preg_match('/bytes=(\d+)-(\d+)?/', $_SERVER['HTTP_RANGE'], $matches);
        $offset = intval($matches[1]);
        $length = (($matches[2]) ? intval($matches[2]) : $filesize) - $offset;
    } else {
        $partialContent = false;
    }


    if ( $partialContent ) {
        // output the right headers for partial content
        header('HTTP/1.1 206 Partial Content');
        header('Content-Range: bytes ' . $offset . '-' . ($offset + $length-1) . '/' . $filesize);
    }else{
        header('HTTP/1.1 200 OK');
    }

    // output the regular HTTP headers
    header('Content-Type: video/mp4');
    header('Content-Length: ' . $length);
    header('Accept-Ranges: bytes');
    header('ETag: "3410d79f-576de84c004aa"');
    header('Last-Modified: '.gmdate('D, d M Y H:i:s \G\M\T', $lastMod)); 

    // don't forget to send the data too
    $file = fopen($file, 'r');

    // seek to the requested offset, this is 0 if it's not a partial content request
    fseek($file, $offset);

    //populate $data with all except the last byte of the file
    $numBytes=($length);
    $dataLen=0;
    while($dataLen<$numBytes){
        $lenGrab=($numBytes-$dataLen);
        if($lenGrab>(1024*2700)){$lenGrab=(1024*2700);}
        $data=fread($file, $lenGrab);
        print($data);
        $dataLen+=strlen($data);
    }

    fclose($file);
}else{
    echo "You are not authorized to view this media.";
}

?>

如果有人可以使用此工具，那么您真的是超级英雄！

If someone can get this thing to work, you are seriously a superhero!

最终更新（现在……）

经过很多小时的挫折之后，我不得不放弃这种方法，尝试一些不同的方法。幸运的是，通常有不止一种方法可以完成某件事，而我发现了另一种方法。我将doc根目录下的.mp4文件托管在使用HTTP Basic Auth保护的文件夹中。与我要达到的目标非常相似，它正在为我工​​作。谢谢您的建议和指导！

Well, after many, many hours of frustration, I had to abandon the approach and try something different. Luckily, there are usually more than one way to accomplish something, and I have found another way. I am hosting the .mp4 files inside the doc root in a folder protected using HTTP Basic Auth. Very similar to what I was trying to achieve and it is working for me. Thanks for your advice and direction!

推荐答案

您的标头都是一样的，这就是问题所在。使它们相同：P

Your headers are "all but identical" and there is the problem. Make them identical :P

使用浏览器上的开发人员工具（F12），并检查每个请求发出的网络标头。最可能的原因是我在类似项目中使用的以下几行，但您似乎不见了：

Use the developer tools on your browser, (F12) and check the network headers each request is making. The most likely causes are the following lines I used on a similar project and you seem to be missing:

header('Content-Description: File Transfer');
header('Content-Disposition: inline; filename=' . basename($file));

或者它可能想要

header('Content-Disposition: attachment; filename=' . basename($file));

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