Bug 352673

Summary:	Titles with keyframeable filters (e.g. composite) show up too early
Product:	[Applications] kdenlive	Reporter:	marcin
Component:	Video Effects & Transitions	Assignee:	Vincent PINON <vpinon>
Status:	RESOLVED FIXED
Severity:	normal	CC:	jb
Priority:	NOR
Version First Reported In:	unspecified
Target Milestone:	---
Platform:	Compiled Sources
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:	15.12.0
Sentry Crash Report:
Attachments:	Transition offset No transition offset here

Description marcin 2015-09-13 19:55:07 UTC

In a video I'm working on I use title clips with 4 keyframes in the transition filter (opacity 0, opacity 100%, opacity 100%, opacity 0). For some of them, the actual clip shows up before its time for a brief moment.
The issue only appears in the rendered video, preview is fine.

Other observations:
- removing the title clip from the timeline, inserting it again and recreating the keyframes doesn't change anything,
- the issue appears no matter what video codec is used (kind of obvious),
- it occurs for both the "Composite" and "Affine" transition so it's probably not specific to any of them,
- I wasn't able to reproduce it in a simple project.

Version: compiled from v15.08.0 tag.
Rendered video with the issue (see second 20 and 28): http://marcin.studio4plus.com/files/kdenlive-keyframe-bug.mp4
Project files for the video: http://marcin.studio4plus.com/files/kdenlive-keyframe-bug.zip
It's the two "Composite" transitions that exhibit the bug.

Reproducible: Always

Comment 1 Vincent PINON 2015-09-13 20:44:39 UTC

Hello,

Thanks for the report ; we are struggling for long with bugs in the titler module, without solution for the moment despite asking Qt experts.
As a workaround, try to create images for your problematic titles (beware that Qt doesn't handle all SVGs perfectly, so a correctly sized PNG is preferable).

As a side note, we've been working hard this week to get a more reliable 15.8.1, not already released but source code available on git ;-)

Comment 2 marcin 2015-09-14 17:44:25 UTC

The bug is about keyframes, not titles. In fact, I can reproduce it with slideshows as well.

Comment 3 Jean-Baptiste Mardelle 2015-09-14 20:24:28 UTC

Created attachment 94562 [details]
Transition offset

Comment 4 Jean-Baptiste Mardelle 2015-09-14 20:28:40 UTC

Hello Marcin,

I opened the attached project, and looking closely at the transitions that cause your problem, you can see on my attached screenshot "Transition offset" that the transitions are not aligned with the title clips... The clip starts before the transition which explains the problem.

Do you have an explanation why this transitions are not aligned ? Moving them should solve the problem..

Comment 5 marcin 2015-09-14 20:33:27 UTC

Created attachment 94564 [details]
No transition offset here

Comment 6 marcin 2015-09-14 20:34:49 UTC

I don't have the offset here, I would love to just move the titles to align them :)
I would test with the current master but it doesn't seem to compile...

Comment 7 marcin 2015-09-14 20:55:38 UTC

I had to upgrade mlt to 0.9.8 to compile master.
I can confirm that the displacement is visible in kdenlive built from the today's master and I can align the tracks to fix the issue (also in the rendered file).

As far as I'm concerned the issue may be closed as resolved (unless you want to find and backport the fix or something).
Thanks!