[Bug 722697] New: Adding an input dynamixally to videomixer using xvimagesink produces QOS events

[GStreamer (bugzilla.gnome.org)]

https://bugzilla.gnome.org/show_bug.cgi?id=722697
  GStreamer | gstreamer (core) | 1.2.2

           Summary: Adding an input dynamixally to videomixer using
                    xvimagesink produces QOS events
    Classification: Platform
           Product: GStreamer
           Version: 1.2.2
        OS/Version: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: Normal
         Component: gstreamer (core)
        AssignedTo: gstreamer-bugs at lists.freedesktop.org
        ReportedBy: lauchapc87 at gmail.com
         QAContact: gstreamer-bugs at lists.freedesktop.org
     GNOME version: ---


Created an attachment (id=266874)
 --> (https://bugzilla.gnome.org/attachment.cgi?id=266874)
example's app showing the bug

If we have a pipe like this:
    videotestsrc ! video/x-raw, width=<w>, height=<h> ! videomixer !
xvimagesink

Then on PLAYING_STATE:

1. Wait for a arbitrary period of time.
2. Set the pipe on PAUSED_STATE.
3. Request a new pad on the mixer.
4. Call gst_pad_set_offset(<current_running_time) on the new mixer's pad.
5. Create a bin (filesrc ! matroskademux ! theoradec).
6. Link the bin and the new mixer's sink pad.  
7. Call gst_element_sync_state_with_parent on the bin
8. Set the pipeline on PLAYING_STATE.

The result is that the new video is showed during a short time. 
The decoder shows "dropping frame because of QoS".

The video referenced in the example's code was generated with:
 gst-launch-1.0 -e videotestsrc ! timeoverlay font-desc=60 ! video/x-raw,
width=250,height=250 ! theoraenc ! matroskamux ! filesink location=video.mkv


Notes:
   * If we use videotestsrc instead of filesrc on step 5, the pipe works OK.
   * Using fakesink or filesink instead of xvimagesink works OK.
   * If we drop the QOS on the decoder's src pad the video is showed correctly.

-- 
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.