• Download a sample video:

wget https://test-videos.co.uk/vids/bigbuckbunny/mp4/h264/360/Big_Buck_Bunny_360_10s_20MB.mp4

• Copy it on your board (here the board name is "H3")

scp ./Big_Buck_Bunny_360_10s_20MB.mp4 h3:/media

• connect to your board:

ssh h3

• Open a user session

su - agl-driver

• start the gstream command

export XDG_RUNTIME_DIR=/run/user/1001
gst-launch-1.0 filesrc location=/media/Big_Buck_Bunny_360_10s_20MB.mp4 ! qtdemux ! queue ! h264parse ! omxh264dec ! waylandsink

etting pipeline to PAUSED ...
ERROR: Pipeline doesn't want to pause.
WARNING: from element /GstPipeline:pipeline0/GstWaylandSink:waylandsink0: Could not initialise Wayland output
Additional debug info:
../git/ext/wayland/gstwaylandsink.c(399): gst_wayland_sink_find_display (): /GstPipeline:pipeline0/GstWaylandSink:waylandsink0:
Failed to create GstWlDisplay: 'Failed to connect to the wayland display '(default)''
Setting pipeline to NULL ...
Freeing pipeline ...

To solve the issue in command line, you can try

• connect to your board:
  ssh h3

chsmack -a '*' /dev/rgnmm
chsmack -a '*' /dev/uvcs
chsmack -a '*' /dev/rgnmmbuf
chsmack -a '*' /dev/vspm_if

chmod 0666 /dev/rgnmm
chmod 0666 /dev/uvcs
chmod 0666 /dev/rgnmmbuf
chmod 0666 /dev/vspm_if

usermod -a -G display agl-driver

• Open a user session
  su - agl-driver
  export XDG_RUNTIME_DIR=/run/user/1001
  gst-launch-1.0 filesrc location=/media/Big_Buck_Bunny_360_10s_20MB.mp4 ! qtdemux ! queue ! h264parse ! omxh264dec ! waylandsink

You can also create an udev rule to fix this issue

vi /etc/udev/rules.d/73-gst.rules

KERNEL=="rgnmm", GROUP="display", MODE="0660", SECLABEL

{smack}="*"
KERNEL=="uvcs", GROUP="display", MODE="0660", SECLABEL{smack}

="*"
KERNEL=="rgnmmbuf", GROUP="display", MODE="0660", SECLABEL

{smack}="*"
KERNEL=="vspm_if", GROUP="display", MODE="0660", SECLABEL{smack}

="*"