Bug 355003

Summary:	15.11.80: applying speed effect, changing speed also changes beginning of clip.
Product:	[Applications] kdenlive	Reporter:	Wegwerf <wegwerf-1-2-3>
Component:	User Interface & Miscellaneous	Assignee:	Jean-Baptiste Mardelle <jb>
Status:	RESOLVED INTENTIONAL
Severity:	normal	CC:	nuzzigio, qubodup, wegwerf-1-2-3
Priority:	NOR
Version First Reported In:	unspecified
Target Milestone:	---
Platform:	Compiled Sources
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:
Attachments:	Clip in timeline changes its beginning with speed=300%

Description Wegwerf 2015-11-07 19:08:07 UTC

When adding a speed effect on a clip, Kdenlive does not correctly the maximum length of the clip. In particular, even at 100% speed it shrinks a clip in the timeline when it shouldn't. Also with, say 200% speed, it is not possible to fully enlarge the clip up to its correct end. Instead, due to some miscalculations, parts of the original clip become inaccessible when a speed effect is present.

Reproducible: Always

Steps to Reproduce:
1. Add a clip of, say, 3 minutes length to the project bin. This needs to be a real clip, not a color clip.
2. Set a region with in=2:57:00 and out=3:00:00 on the clip in the clip monitor.
3. Drag this region into the timeline.
4. Add speed effect to this clip in the timeline.

Actual Results:  
Albeit the Speed effect has default Speed=100% the clip in the timeline shrinks.

Expected Results:  
Clip in timeline does not shrink when Speed effect with default 100% speed is applied.

Comment 1 qubodup 2015-11-24 06:33:38 UTC

In recent git version of kdenlive..

I am not able to reproduce this issue by following your steps
https://youtu.be/uzneXRV4yGE

I used
https://archive.org/download/StockVideoGameVideo/TriggerRallyGeneralPurposeVideo.mp4 (MPEG4 download at https://archive.org/details/StockVideoGameVideo ) for testing.

Can you reproduce it with the video I used?

Comment 2 Wegwerf 2015-11-29 16:25:45 UTC

I also cannot reproduce the shrinking effect using the test clip and using the final 3minutes segment from it.

However, when changing the speed to 300% the beginning of the sped-up clip now changes and is incorrect. You can easily see this by having both the clip and project monitors open simultaneously and then moving one frame forward, then back, in the timeline: the timeline clip with the speed effect now shows a completely different segment than the clip monitor.

I've updated the bug title to reflect this.

Comment 3 Wegwerf 2015-11-29 16:30:09 UTC

Created attachment 95806 [details]
Clip in timeline changes its beginning with speed=300%

The clip monitor shows the original beginning of the section that has been also dragged to the timeline; this section is the final 3 minutes of the demo video clip. After applying the speed effect and setting the speed to 300% the beginning of the clip with the effect changes, as can be seen in the project monitor. You need to move one frame forward, then back, to correctly update the project monitor.

Comment 4 Wegwerf 2016-04-17 16:15:33 UTC

As the speed effect has been changed, I'm retiring this bug as it relates to the old, now obsolete implementation of the speed effect.