Discoverer maintain a referernce on the discoverer object while
the async timeout callback is alive to prevent a potential crash
if the object is freed while the callback is pending.
But if g_main_context is released before calling the timeout callback,
the discoverer pointer which was weak referenced from GESUriClipAssetClass
will not be disposed because the discoverer object is not finalized.
And handle the fact that adding to a layer can fail.
Also plug some leaks in the dispose method (and use the dispose
vmethod instead of finalize as appropriate).
Basically if we do not emit a "duration" change of the clip being
splitted first when executing the 'reverse' operations would lead
to fully overallaping clips.
This is implemented on top of a Tree that represents the whole timeline.
SourceClips can not fully overlap anymore and the tests have been
updated to take that into account. Some new tests were added to verify
that behaviour in greater details
Each timeline element is in a layer (potentially spanning
over several), it is very often useful to retrieve an element
layer priority (from an app perspective more than the element
priority itself as that is a bit of an implementation detail
in the end).
Port tests to it
Auto transition when having 3 overlapping clips in a same point in the
timeline is not supported as we can't handle it in a nice way. Before we
to avoid creating 2 overlapping transitions (which is plain broken in
NLE) were completely disabling `auto-transition` and removing all
auto-transitions in the timeline but this is pretty weird for the end
user. This commit changes and now makes sure 2 transitions are not
created in the same place.
Also cleanup previous test case.
And start handling relocated assets.
Also expose the discoverer callback as a vmethod so that we can
overridde the discoverer when necessary (to handle discovering of
timeline through gesdemux for example)
This reverts commit e939cfebaf.
Class might not be initialized if they were already registered
when ges_init() was called, but were not created until ges_deinit() called.
To support ges_{init/deinit} multiple times in a process,
there should be a method for setting up internal object/table of
GESUriClipAssetClass. because *_class_init() will be called
only once in process lifecycle.
