Editing has been simplified by breaking down each edit into a
combination of three basic single-element edits: MOVE, TRIM_START, and
TRIM_END.
Each edit follows these steps:
+ Determine which elements are to be edited and under which basic mode
+ Determine which track elements will move as a result
+ Snap the edit position to one of the edges of the main edited element,
(or the edge of one of its descendants, in the case of MOVE), avoiding
moving elements.
NOTE: in particular, we can *not* snap to the edge of a neighbouring
element in a roll edit. This was previously possible, even though the
neighbour was moving!
+ Determine the edit positions for clips (or track elements with no
parent) using the snapped value. In addition, we replace any edits of
a group with an edit of its descendant clips. If any value would be
out of bounds (e.g. negative start) we do not edit.
NOTE: this is now done *after* checking the snapping. This allows the
edit to succeed if snapping would cause it to go from being invalid to
valid!
+ Determine whether the collection of edits would result in a valid
timeline-configuration which does not break the rules for sources
overlapping.
+ If all this succeeds, we emit snapping-started on the timeline.
+ We then perform all the edits. At this point they should all succeed.
The simplification/unification should make it easier to make other
changes.
Fixes https://gitlab.freedesktop.org/gstreamer/gst-editing-services/-/issues/97
Fixes https://gitlab.freedesktop.org/gstreamer/gst-editing-services/-/issues/98
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-editing-services/-/merge_requests/169>
Avoid loosing (too much) precision when rescaling back and forth by
storing values in gdoubles.
Handle the fact that position values can be negative
Also fix debug category static variable
as it clashes with the instance variable name in a few methods.
APIs:
- ges_timeline_get_frame_time
- ges_timeline_get_frame_at
- ges_clip_asset_get_frame_time
- ges_clip_get_timeline_time_from_source_frame
Extracting ges_util_structure_get_clocktime to internal utilities adding
support for specifying timing values in frames with the special
f<frame-number> synthax.
We try to do our best to have the video frames scaled the best way
to fill most space on the final frames, keeping aspect ratio. The user
can later on rescale or move the sources as usual but it makes the
default behaviour a better and more natural especially now that we
set default restriction caps to the video tracks.
And fix the unit test to take that change into account
Basically we were advertising that the source size would be the
size of the track if it hadn't been defined by end user, but since
we started to let scaling happen in the compositor, this is not true
as the source size is now the natural size of the underlying video
stream.
Remove the unit test and reimplemented using a validate scenario which
make the test much simpler to read :=)
