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
GstDiscoverer objects were leaked by tests making the leaks detector
unusable.
Introduce ges_deinit(), similiar to gst_deinit(), doing some cleanup
before exiting the process.
https://bugzilla.gnome.org/show_bug.cgi?id=776805
GESLayer is now responsible for setting clips priorites. Also
GESClip top effects priorities are now set by the
ges_clip_set_top_effect_index method, the user should never call
ges_timeline_element_set_priority as it will anyway be overriden
by GES itself.
Differential Revision: https://phabricator.freedesktop.org/D1280
Fix all tests as we now have 1 priority inside the layer
dedicated to transitions (basically no source clip will
ever have a priority of 0 inside a layer).
Differential Revision: https://phabricator.freedesktop.org/D1276
And simplify the way we start computing children priority
making min_priority already relative to the clip itself.
Differential Revision: https://phabricator.freedesktop.org/D1275
And reuse the same previously created element when adding the clip
back to a layer, avoiding losing all setting done on clip children
in that situation
This is a behaviour change but previous behaviour was actually totally
unexpected and people working around that weird behaviour will moste
probably not care about that change
Differential Revision: https://phabricator.freedesktop.org/D1094
Before this patch, NLE and GES did not support NleOperations (respectively
GESEffects) that changed the speed/tempo/rate at which the source plays. For
example, the 'pitch' element can make audio play faster or slower. In GES 1.5.90
and before, an NleOperation containing the pitch element to change the rate (or
tempo) would cause a pipeline state change to PAUSED after that stack; that has
been fixed in 1.5.91 (see #755012 [0]). But even then, in 1.5.91 and later,
NleComposition would send segment events to its NleSources assuming that one
source second is equal to one pipeline second. The resulting early EOS event
(in the case of a source rate higher than 1.0) would cause it to switch stacks
too early, causing confusion in the timeline and spectacularly messed up
output.
This patch fixes that by searching for rate-changing elements in
GESTrackElements such as GESEffects. If such rate-changing elements are found,
their final effect on the playing rate is stored in the corresponding NleObject
as the 'media duration factor', named like this because the 'media duration',
or source duration, of an NleObject can be computed by multiplying the duration
with the media duration factor of that object and its parents (this is called
the 'recursive media duration factor'). For example, a 4-second NleSource with
an NleOperation with a media duration factor of 2.0 will have an 8-second media
duration, which means that for playing 4 seconds in the pipeline, the seek
event sent to it must span 8 seconds of media. (So, the 'duration' of an
NleObject or GES object always refers to its duration in the timeline, not the
media duration.)
To summarize:
* Rate-changing elements are registered in the GESEffectClass (pitch::tempo and
pitch::rate are registered by default);
* GESTimelineElement is responsible for detecting rate-changing elements and
computing the media_duration_factor;
* GESTrackElement is responsible for storing the media_duration_factor in
NleObject;
* NleComposition is responsible for the recursive_media_duration_factor;
* The latter property finally fixes media time computations in NleObject.
NLE and GES tests are included.
[0] https://bugzilla.gnome.org/show_bug.cgi?id=755012
Differential Revision: https://phabricator.freedesktop.org/D276
