pipewiresrc element does not report it's latency

Created by: ndufresne

I was testing pipewire, notice that I was using Fedora 27 released version, I notice that all video frame were late. It seems like pulewiresrc pretend there is no lateny, but uses HW timestamp.

[nicolas@skullcanyon ~]$ gst-launch-1.0 pipewiresrc path=4 ! glimagesink 
Setting pipeline to PAUSED ...
Pipeline is live and does not need PREROLL ...
Got context from element 'sink': gst.gl.GLDisplay=context, gst.gl.GLDisplay=(GstGLDisplay)"\(GstGLDisplayX11\)\ gldisplayx11-0";
Setting pipeline to PLAYING ...
New clock: pipewireclock0
WARNING: from element /GstPipeline:pipeline0/GstGLImageSinkBin:glimagesinkbin0/GstGLImageSink:sink: A lot of buffers are being dropped.
Additional debug info:
gstbasesink.c(2901): gst_base_sink_is_too_late (): /GstPipeline:pipeline0/GstGLImageSinkBin:glimagesinkbin0/GstGLImageSink:sink:
There may be a timestamping problem, or this computer is too slow.