i'm having a problem with ARToolKit for the recognition of multiple markers. For train pc on my new markers i have to launch :MK_PATT But when i insert the camera parameter filename ,i have this error message:

{ `Using supplied video config string [videotestsrc]. libARvideo: GStreamer 0.10.36

(mk_patt:2895): GLib-GObject-WARNING **: invalid cast from GstVideoTestSrc' toGstBin'

(mk_patt:2895): GStreamer-CRITICAL **: gst_bin_get_by_name: assertion GST_IS_BIN (bin)' failed
Pipeline has no element named 'artoolkit'!
setupCamera(): Unable to open connection to camera.
main(): Unable to set up AR camera.
}