首页 > 解决方案 > Chrome 问题 - 视频流和会话冲突

问题描述

我在 javascript 和 PHP 中实现视频时遇到问题。

索引.php

session_start()

// do other stuff
include ‘video.php’

视频.php

<?php
If(!$_REQUEST[‘play’]){
    // displaying video.html
}
else
{
    // play video
$fp = @fopen($file, 'rb');

$size   = filesize($file); // File size
$length = $size;           // Content length
$start  = 0;               // Start byte
$end    = $size - 1;       // End byte

// Now that we've gotten so far without errors we send the accept range header

/* At the moment we only support single ranges.
 * Multiple ranges requires some more work to ensure it works correctly
 * and comply with the specifications: http://www.w3.org/Protocols/rfc2616/rfc2616-sec19.html#sec19.2
 *
 * Multirange support announces itself with:
 * header('Accept-Ranges: bytes');
 *
 * Multirange content must be sent with multipart/byteranges media type,
 * (mediatype = mimetype)
 * as well as a boundary header to indicate the various chunks of data.
 */
 
header('Content-type: video/mp4');
header('Accept-Ranges: bytes');
// multipart/byteranges
// http://www.w3.org/Protocols/rfc2616/rfc2616-sec19.html#sec19.2
if (isset($_SERVER['HTTP_RANGE'])){
    $c_start = $start;
    $c_end   = $end;
    // Extract the range string
    list(, $range) = explode('=', $_SERVER['HTTP_RANGE'], 2);
    // Make sure the client hasn't sent us a multibyte range
    if (strpos($range, ',') !== false){
        // (?) Shoud this be issued here, or should the first
        // range be used? Or should the header be ignored and
        // we output the whole content?
        header('HTTP/1.1 416 Requested Range Not Satisfiable');
        header("Content-Range: bytes $start-$end/$size");
        // (?) Echo some info to the client?
        exit;
    } // fim do if

    // If the range starts with an '-' we start from the beginning
    // If not, we forward the file pointer
    // And make sure to get the end byte if spesified
    if ($range{0} == '-'){
        // The n-number of the last bytes is requested
        $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;
    } // fim do if
    /* Check the range and make sure it's treated according to the specs.
     * http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html
     */
    // End bytes can not be larger than $end.
    $c_end = ($c_end > $end) ? $end : $c_end;
    // Validate the requested range and return an error if it's not correct.
    if ($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");
        // (?) Echo some info to the client?
        exit;
    } // fim do if

    $start  = $c_start;
    $end    = $c_end;
    $length = $end - $start + 1; // Calculate new content length
    fseek($fp, $start);
    header('HTTP/1.1 206 Partial Content');
} // fim do if

// Notify the client the byte range we'll be outputting
header("Content-Range: bytes $start-$end/$size");
header("Content-Length: $length");
// Start buffered download
$buffer = 1024 * 8;
while(!feof($fp) && ($p = ftell($fp)) <= $end){
    if ($p + $buffer > $end){
        // In case we're only outputtin a chunk, make sure we don't
        // read past the length
        $buffer = $end - $p + 1;
    } // fim do if
    set_time_limit(0); // Reset time limit for big files
    echo fread($fp, $buffer);
    flush(); // Free up memory. Otherwise large files will trigger PHP's memory limit.
 } // fim do while
 fclose($fp);
 exit();
}

视频.html

<!doctype html>
<html lang="fr-FR">
    <head>
        <meta charset="utf-8">
        <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
    </head>
    <body>
        <video controls>
            <source src="index.php?format=mp4&play=1&id=someid type="video/mp4" />
        </video>
    </body>
</html>

一切正常,但由于某种原因我不知道,当我开始播放视频然后单击页面上的链接或使用浏览器的后退按钮时,浏览器会冻结并等待一段时间(变量),然后再点击链接。

分析器指示请求的页面更改处于挂起状态。

如果我将视频光标放在更远的地方,浏览器会立即解锁并跟随我单击的链接。

最后,如果我重新加载该页面,问题就不会再出现了。似乎 chrome 正在等待某些东西,但由于我的缓存被禁用,它没有被缓存。

这只发生在 chrome 桌面上,所有其他浏览器都能正确完成这项工作。

** 编辑 **

我找到了问题的根源。

要播放我的视频,我会浏览我的主文件index.php,该文件用作我的路由器,我在其中初始化会话session_start()

播放视频时,我单击浏览器的链接或后退按钮,我会返回index.php. 这是 chrome 在 session_start() 期间卡住的时候

只要视频正在播放,会话似乎就存在冲突。

标签: phphttphttp-content-range

解决方案


要防止在现有会话打开时尝试重新启动会话,请使用 session_status:

if (session_status() == PHP_SESSION_NONE) {
    session_start();
}

即使您使用 session_write_close,检查现有会话仍然是一种好习惯。

这样,如果您包含多个文件,每个文件都尝试启动会话,它们将不会相互影响。


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