我想在 php 中使用 ffmpeg 将视频转换为 .flv.目前我有这个工作，但它会挂起浏览器，直到文件上传并完成.我一直在查看有关如何在后台运行 exec() 进程的 php 文档，同时使用返回的 PID 更新进程.这是我发现的:
I am wanting to use ffmpeg to convert video to .flv in php. Currently I have this working, but it hangs the browser until the file is uploaded and is finished. I have been looking at the php docs on how to run an exec() process in the background, while updating the process using the returned PID. Here is what I found:
//Run linux command in background and return the PID created by the OS
function run_in_background($Command, $Priority = 0)
{
if($Priority)
$PID = shell_exec("nohup nice -n $Priority $Command > /dev/null & echo $!");
else
$PID = shell_exec("nohup $Command > /dev/null & echo $!");
return($PID);
}
还有一个技巧可以用来跟踪后台任务是否正在使用返回的 PID 运行:
There is also a trick which I use to track if the background task is running using the returned PID :
//Verifies if a process is running in linux
function is_process_running($PID)
{
exec("ps $PID", $ProcessState);
return(count($ProcessState) >= 2);
}
我想创建一个单独的 .php 文件，然后从 php cli 运行以执行这些功能之一吗?我只需要稍微推动一下就可以让它工作，然后我就可以从那里开始了.
Am I suppose to create a separate .php file which then runs from the php cli to execute one of these functions? I just need a little nudge in getting this working and then I can take it from there.
谢谢！
我想创建一个单独的 .php然后从 php cli 运行的文件执行这些功能之一?
Am I suppose to create a separate .php file which then runs from the php cli to execute one of these functions?
这可能是我会做的方式:
This is probably the way I would do it :
还有一些其他的想法:
您的处理脚本"必须每隔几分钟启动一次；如果你在类似 Linux 的机器上，你可以使用 cron.
Your "processing script" would have to be launch every couple of minutes ; you can use cron for that, if you are on a Linux-like machine.
更多信息，在看到评论后
由于处理部分是通过 CLI 而非 Apache 完成的，因此您不需要任何后台"操作:您只需使用 shell_exec，它将在完成工作后将命令的整个输出返回到您的 PHP 脚本.
As the processing part is done from CLI, and not from Apache, you don't need anykind of "background" manipulations : you can just use shell_exec, which will return the whole ouput of the command to your PHP script when it's finished doing it's job.
对于观看网页的用户说正在处理"，它看起来像是在后台处理；而且，在某种程度上，它会是，因为处理将由另一个进程完成(甚至可能在另一台机器上).
For the user watching the web page saying "processing", it will seem like background processing ; and, in a way, it'll be, as the processing will be done by another processus (maybe even on another machine).
但是，对你来说，它会简单得多:
But, for you, it'll be much simpler :
我想您的处理脚本可能看起来像这样:
Your processing script could look like something like this, I suppose :
// Fetch informations from DB about one file to process
// and mark it as "processing"
// Those would be fetched / determined from the data you just fetched from DB
$in_file = 'in-file.avi';
$out_file = 'out-file.avi';
// Launch the ffmpeg processing command (will probably require more options ^^ )
// The PHP script will wait until it's finished :
// No background work
// No need for any kind of polling
$output = shell_exec('ffmpeg ' . escapeshellarg($in_file) . ' ' . escapeshellarg($out_file));
// File has been processed
// Store the "output name" to DB
// Mark the record in DB as "processed"
真的比你最初想象的要容易，不是吗?;-)
不要再担心后台的东西了:唯一重要的是处理脚本会定期从 crontab 启动.
Really easier than what you first thought, isn't it ? ;-)
Just don't worry about the background stuff anymore : only thing important is that the processing script is launched regularly, from crontab.
希望这会有所帮助:-)
Hope this helps :-)
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