Loaded and active filters

[fred.hild]

Hello
I'm using libvlc.dll in a small application (version 0.8.6b) and am trying to use the transform-filter.
I have got it working with the config_PutPsz (to set the vout-filter and transform-type). The problem is that I want to show more than one video and do different transformations on them. I have got i working if I wait some time after the first video started before I'm starting the next one. But I havent found out anything I can wait on so now its just fixed time period.
Can you check somehow when a filter is active and loaded? Or change the filters settings when it is loaded?

Thanks in advance / fred.hild