API/ABI
-------

- implement return values from events in addition to the gboolean. This should be
  done by making the event contain a GstStructure with input/output values, similar
  to GstQuery. A typical use case is performing a non-accurate seek to a keyframe,
  after the seek you want to get the new stream time that will actually be used to
  update the slider bar.

- convert framerate to GstFraction in GstCaps.

- implement latency calculation for live sources.

- implement master/slave clocks.

- implement QOS.

- implement BUFFERSIZE.

- make bin_bus_handler a vmethod so subclasses can use their own implementation
  or chain to the parent.

- make it possible to seek on other formats than bytes in basesrc.

- GstFormat, GstQuery quarks, get_name. 

- GstEvent, GstMessage register like GstFormat or GstQuery.

- unblocking while seeking. gst_element_flush_pads (GstElement, gboolean);

- make GstCapsFlags instead of the #define for GST_CAPS_FLAGS_ANY.

- query POSITION/DURATION return accuracy. Just a flag or accuracy percentage.

- add some sort of time/frame stepping functionality, either with a flag on the seek
  event or some new seek event type. The idea would be to operate on the current
  playback position instead of the current configured segment when doing the seek.
  Idea is that frame stepping forwards can be done in the sinks, ie, just dropping
  N frames/time, sending more complicated queries upstream which can ideally handle
  those cases more efficiently too.

- GstClockFlags should use the gstobject flags field instead of inventing its own.

- Add gstsegment.[ch].


IMPLEMENTATION
--------------

- implement clock selection as explained in part-gstpipeline.txt. 


DESIGN
------

- unlinking pads in the PAUSED state needs to make sure the stream thread is not
  executing code. Can this be done with a flush to unlock all downstream chain
  functions? Do we do this automatically or let the app handle this?

- when a pipeline with a live source goes to PAUSED again, a sample is prerolled
  in the sinks. This sample should be discarded, possibly with a flush event
  started from the source.