如何在多个视频上传过程中处理视频编码的排队问题？

你应该使用一个叫 gearman 的软件。它是一个工作服务器，你可以用PHP调用函数。你可以把进程转移到后台，它自动处理排队问题。许多进程也可以并行运行。

我使用过它，它非常容易安装和操作。

对于你的使用情况。

Wrap the ffmpeg process in a php file with exec.
Save the uploaded file to db and give it an id. 
Call the encode function after a user uploads file.
As soon as the encode function starts, 
update the db to reflect that the file was "picked".
First run the ffmpeg info on the file to see if it is fine.
Then encode the file and after it is done, update db flag to "done".
进程完成后，你可以调用另一个函数，向用户发送电子邮件、推特等，说明编码已经完成。