How to know if vlc fails from php?

[panoramix]

Hi,
I have a webserver in which I launch php to do some transcoding jobs using php exec() function... What I would like is being able to know if there is a failure in the transcoding option, and, if possible, to be able to know about the possible reason...
The transcoding parameters are passed in the request, and I'd like to be able to reply with some OK if everything goes ok, or some error message if it has failed...
Any suggestions?
Thanks so much!!!

[bXn]

could you post some of your code here ?

[lokrain]

Use proc_open() function for user interaction or system() for getting only output of vlc. system() can be combined with ob_* functions.