[Bug 735844] New: basetextoverlay/pango: overlay negotiation fails when it should not

[GStreamer (bugzilla.gnome.org)]

https://bugzilla.gnome.org/show_bug.cgi?id=735844
  GStreamer | gst-plugins-base | 1.4.1

           Summary: basetextoverlay/pango: overlay negotiation fails when
                    it should not
    Classification: Platform
           Product: GStreamer
           Version: 1.4.1
        OS/Version: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: Normal
         Component: gst-plugins-base
        AssignedTo: gstreamer-bugs at lists.freedesktop.org
        ReportedBy: rawoul at gmail.com
         QAContact: gstreamer-bugs at lists.freedesktop.org
     GNOME version: ---


Created an attachment (id=285084)
 --> (https://bugzilla.gnome.org/attachment.cgi?id=285084)
Log of events in basetextoverlay and the sink that supports overlay

I'm hitting an issue which was not happening in gstreamer 1.2, where the
overlay composition negotiation fails. In my pipeline blending subtitles over
video frames is not supported, as it is waaay to slow for my system to do that.
So in all cases I _must_ be using an overlay. I've updated my sink code to
handle overlay negotiation with proper caps features (namely,
memory:SystemMemory and meta:GstVideoOverlayComposition).

The issue is that sometimes overlay negotiation fails while seeking. I've
attached a log of the relevant events between the textoverlay element and my
sink.

The overlay negotiation features is working (in the log: Downstream accepts the
overlay meta: 1), but then caps setting fails because the pad is flushing, so
the ALLOCATION query is not done. This results in the overlay being disabled.
The caps are then never being re-negotiated.

I'm not sure what regressed compared to gstreamer 1.2, it could be either the
textoverlay code or a deeper issue related to events and pads.

-- 
Configure bugmail: https://bugzilla.gnome.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the QA contact for the bug.
You are the assignee for the bug.