php stream任何mp4

Question

我正在开发一个可以转换视频并允许通过Flowplayer播放视频的网络应用。

在当前状态下，我使用 ffmpeg 将视频转换为mp4和 qtfaststart 来修复其流式传输元数据。一切顺利，因为我可以下载任何转换后的mp4并正确查看。

为了将视频提供给Flowplayer，我使用的php文件包含以下（汇总）代码：

header("Content-Type: {$mediatype}");

if ( empty($_SERVER['HTTP_RANGE']) )
{
    if ( $filetype == 'flv' && $seekPos != 0 )
    {
        header("Content-Length: " . ($filesize + 13));
        print('FLV');
        print(pack('C', 1));
        print(pack('C', 1));
        print(pack('N', 9));
        print(pack('N', 9));
    }
    else
    {           
        header("Content-Length: {$filesize}");
    }

    $fh = fopen($filepath, "rb") or die("Could not open file: {$filepath}");

    # seek to requested file position
    fseek($fh, $seekPos);

    # output file
    while(!feof($fh))
    {
        # output file without bandwidth limiting
        echo fread($fh, $filesize);
    }
    fclose($fh);
}
else //violes rfc2616, which requires ignoring  the header if it's invalid
{   
    $fp = @fopen($file, 'rb');

    $size   = filesize($file); // File size
    $length = $size;           // Content length
    $start  = 0;               // Start byte
    $end    = $size - 1;       // End byte
    // Now that we've gotten so far without errors we send the accept range header
    /* At the moment we only support single ranges.
     * Multiple ranges requires some more work to ensure it works correctly
     * and comply with the spesifications: http://www.w3.org/Protocols/rfc2616/rfc2616-sec19.html#sec19.2
     *
     * Multirange support annouces itself with:
     * header('Accept-Ranges: bytes');
     *
     * Multirange content must be sent with multipart/byteranges mediatype,
     * (mediatype = mimetype)
     * as well as a boundry header to indicate the various chunks of data.
     */
    header("Accept-Ranges: 0-$length");
    // 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/$size");
            // (?) Echo some info to the client?
            exit;
        }
        // If the range starts with an '-' we start from the beginning
        // If not, we forward the file pointer
        // And make sure to get the end byte if spesified
        if ($range0 == '-')
        {

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

    // 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 - $p + 1;
        }
        set_time_limit(0); // Reset time limit for big files
        echo fread($fp, $buffer);
        flush(); // Free up memory. Otherwise large files will trigger PHP's memory limit.
    }

    fclose($fp);
}

不幸的是，它仅适用于大多数视频。对于其中一些，Flowplayer会继续返回错误200，即使它们编码正确。

我该如何解决这个问题？这是编码问题还是那些视频有问题？