https://bugs.kde.org/show_bug.cgi?id=505407
Bug ID: 505407
Summary: [Feature Request] Use Timeline or Clip Markers to
split clip into pieces
Classification: Applications
Product: kdenlive
Version First unspecified
Reported In:
Platform: Ubuntu
OS: Linux
Status: REPORTED
Severity: wishlist
Priority: NOR
Component: Timeline & Editing
Assignee: j...@kdenlive.org
Reporter: luca...@protonmail.com
Target Milestone: ---
It would be nice if there was a way of cutting a video using certain moments
know previously.
Some use cases:
- I want to make a video where the image is synchronized with a music beat. So,
I can use an audio
processing program to give me a list of beat moments, and I'll cut the video
in these moments, which will
be imported as markers. But doing it by pressing Alt+Right and Shift+R would
take a long time.
An automated way of doing it would be better.
- I have some video pre-processing program that gives me certain key points
based on certain metrics - e.g.
funny moments from a podcast or movie - and I want to use this data to
generate clips of key moments and
discard the rest.
I've searched for related requests, and I've found these:
https://bugs.kde.org/show_bug.cgi?id=388122
https://bugs.kde.org/show_bug.cgi?id=486249
https://bugs.kde.org/show_bug.cgi?id=501704
I've checked some of the tasks existent, and I could come with a solution based
on `scenesplittask.cpp`. The user will be able to choose between using timeline
or clip markers. He'll also be able to choose the category and if he wants to
keep even or odd clips - or both. There's also an option to add the resulting
clips as subclips under the main clip's tree.
To do this, i've basically used zones. I read the desired Markers' frames and
used them to create zones from
the original clip. These zones are then put into timeline with `insertZone()`
and - if the user wants - they are added as subclips using `loadSubclips`.
The problem is: iterating a list of zones and calling insertZone in each of
them doesn't seem to work well. It
seems that it overload and crash the app, and I don't know exactly where. Maybe
the GUI thread gets too busy when it inserts a certain amount of zones into
timeline, but I'm not sure where the bottleneck is. I thought that it was
overloading the TaskManager's thread pool, but it doesn't seem to be it since
I've tracked the tasks being executed, and no task seems to be run during the
insertion.
The way I solved the crash caused by this bottleneck was delaying each zone
insertion by some miliseconds, with QThread::msleep. It's not an elegant
solution, since it's a blocking solution, but since AbstracktTask runs in a
separate thread, using it souldn't block the main thread, and since I've used
it I didn't have more crash problems.
There are certainly non-blocking ways of doing the same thing, but it seems to
me that such solutions would need first to use some signal related to UI
events, so that it may know when the UI is overloaded - and shouldn't receive
more timeline insert requests - and when it is ready to do it.
Since I'm not very familiar with C/C++ and certainly not very familiar with QT,
some suggestions would be welcome. Also, opinions about the viability of
implementing this feature currently are welcome. I've seem some discussions
about using only Markers and abandoning Guides, and this feature may make this
and other changes more complicated.
You may check the code at
https://invent.kde.org/lucartc/kdenlive/-/tree/work/masssplittask?ref_type=heads
in files:
- src/jobs/markersplittask.h
- src/jobs/markersplittask.cpp
--
You are receiving this mail because:
You are watching all bug changes.
