Gstreamer video pipes doesn't work on agl-compositor 0.0.19.
A simple test video pipe like this:
gst-launch-1.0 autovideosrc ! glimagesink / waylandsink

Either waylandsink or glimagesink, the pipe generate following logs with debug level 3:

Setting pipeline to PAUSED ...
0:00:00.211935334 884 0x790fb0 FIXME default gstutils.c:3980:gst_pad_create_stream_id_internal:<autovideosrc0-actual-src-pipewir:src> Creating random stream-id, consider implementing a deterministic way of creating a stream-id

But there are a difference between glimagesink and waylandsink, it is about agl-compositor logs & reaction. With implementing waylandsink, agl-compositor doesn't produce any log, and It looks like It doesn't notice the pipe request at all ! ... but with glimagesink element, agl-compositor get the surface request signal with "null" app_id, but It doesn't step forward, and the request remained in "pending" status. The following logs belong to the situation:

[05:45:49.005] Setting surface to initial size of surface to 800x416
[05:45:49.005] Added surface 0x1b0ead0, app_id (null) to pending list

After we destroy the pipe, agl-compositor notice that with the below log:

[05:48:39.238] Removed surface 0x1b0ead0, app_id (null), role NONE

On the qemu-x86_64 image, It doesn't produce much log on journal by default, after a few tries just I could see the following warning on journal (with Weston default debug level):

│Jul 20 16:10:47 qemux86-64 wireplumber[260]: wp_global_bind: assertion 'global->proxy' failed
│Jul 20 16:10:47 qemux86-64 wireplumber[260]: wp_proxy_set_pw_proxy: assertion 'proxy' failed

After increasing agl-compositor log level to 3, now we get these logs on journal:

agl_ivi_demo_master_qemu_journal.log