如何从php中的BLOB播放流音频？

Question

我有这个smartReadFile（）php函数，允许播放文件中的音频流。你如何修改这个函数，以便它查询mysql数据库BLOB而不是读取特定的文件？

function smartReadFile($location, $filename, $mimeType = 'audio/octet-stream')
{
if (!file_exists($location))
{
    header ("HTTP/1.1 404 Not Found");
    return;
}

$size   = filesize($location);
$time   = date('r', filemtime($location));

$fm     = @fopen($location, 'rb');
if (!$fm)
{
    header ("HTTP/1.1 505 Internal server error");
    return;
}

$begin  = 0;
$end    = $size - 1;

if (isset($_SERVER['HTTP_RANGE']))
{
    if (preg_match('/bytes=\h*(\d+)-(\d*)[\D.*]?/i', $_SERVER['HTTP_RANGE'], $matches))
    {
        $begin  = intval($matches[1]);
        if (!empty($matches[2]))
        {
            $end    = intval($matches[2]);
        }
    }
}

if (isset($_SERVER['HTTP_RANGE']))
{
    header('HTTP/1.1 206 Partial Content');
}
else
{
    header('HTTP/1.1 200 OK');
}

header("Content-Type: $mimeType"); 
header('Cache-Control: public, must-revalidate, max-age=0');
header('Pragma: no-cache');  
header('Accept-Ranges: bytes');
header('Content-Length:' . (($end - $begin) + 1));
if (isset($_SERVER['HTTP_RANGE']))
{
    header("Content-Range: bytes $begin-$end/$size");
}
header("Content-Disposition: inline; filename=$filename");
header("Content-Transfer-Encoding: binary");
header("Last-Modified: $time");

$cur    = $begin;
fseek($fm, $begin, 0);

while(!feof($fm) && $cur <= $end && (connection_status() == 0))
{
    print fread($fm, min(1024 * 16, ($end - $cur) + 1));
    $cur += 1024 * 16;
}
}