VLC and 2x2 mosaic

[prune]

Hi,

I need to start VLC on a laptop (Mac Mini for testing purpose) and display a 2x2 mosaic of 4 iptv multicast channels (239.1.1.1->4).
I've found some configs for doing this but none of them work with latest VLC release.
It's like the "fake" parameters used does not exists anymore, as well as the mosaic options, not displayes with a "-h" option.

Do you have any advice to give ?
FYI, this is what I tried : http://wiki.videolan.org/Mosaic

Thanks.