dsplink with gstreamer-ti plugin can't be started to play video

hi.all

    I have compiled all the dsplink modules, and gstreamer-ti plugin.

but when I test the gstreamer-ti to play video, I got this:

0:00:03.937866209 1672 0x300850 ERROR TIDmaiVideoSink gsttidmaivideosink
.c:1077:gst_tidmaivideosink_init_display: Failed to open display device

0:00:03.938262938 1672 0x300850 ERROR TIDmaiVideoSink gsttidmaivideosink
.c:1249:gst_tidmaivideosink_render: Unable to initialize display

can you tell me something about this error? I even read the source
code, but I am still in search.
I think, is it lack of any drivers of display device?

thanks!

hi. all

sorry for that, I should give out the command what I used:

root@beagleboard:/usr/share/ti-codec-combos# gst-launch
--gst-debug=TI*:2 filesrc location=/home/root/mediaFile/4.mp4 !
typefind ! qtdemux name=demux demux.audio_00 ! queue
max-size-buffers=1800 max-size-time=0 max-size-bytes=0 ! typefind !
TIAuddec1 ! alsasink demux.video_00 ! typefind ! TIViddec2 !
TIDmaiVideoSink videoStd=D1_NTSC displayDevice=/dev/fb2
displayStd=fbdev

any ideas?