Bug 355425

Summary:	Feature request - Able to start/stop/re-start multiple renderings
Product:	[Applications] kdenlive	Reporter:	Evert Vorster <evorster>
Component:	User Interface & Miscellaneous	Assignee:	Jean-Baptiste Mardelle <jb>
Status:	RESOLVED FIXED
Severity:	normal	CC:	qubodup, wegwerf-1-2-3
Priority:	NOR
Version First Reported In:	unspecified
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Evert Vorster 2015-11-16 12:07:31 UTC

I have a lot of GoPro footage that was shot from a drone. The resolution is 4K25fps. I apply defish, color levels adjustment, white balance and sharpening to the footage, and then render out to 1080p25fps.

Since the effects stack effectively only uses one of my CPU cores, and is so slow that the encoder alsmost does not register on the other cores, I was thinking that it would be nice to have some more control of the jobs that are in the list. One should be able to save/restore the jobs, as well as start as many of them as one would like, and have them run at the same time. 

Also, some crash recovery would be nice, as all the jobs in the queue disappears when kdenlive crashes, and with the size of footage involved it happens more often that I would like. 

Reproducible: Always

Comment 1 qubodup 2016-01-04 22:00:07 UTC

Did you set "encoder threads" to a number other than 1?

Workaround:

In the render widget, use "Generate Script" and use the default directory.

Make sure to change the Output file name each time you press "Generate Script"

To render multiple jobs at once, use terminals to launch multiple script files.

Comment 2 Wegwerf 2016-08-05 18:19:28 UTC

Qubodup, I understand Evert to asking for concurrent render jobs, not for multithreaded rendering. Depending on the system RAM configuration and project complexity, it may be possible to render two or three jobs concurrently.

Comment 3 Evert Vorster 2016-09-30 10:12:38 UTC

That is correct.

I would like to be able to start rendering another job while another job is rendering. 

My home desktop system has 8 threads and 26GB of ram, and quite often a number of the cores are sitting idle when I render. Being able to start, pause and stop a rendering job would be awesome. 

This might be a little outside the scope of this report, but if the renderings were done in cgroups it would be possible to not only start, stop and pause jobs, but also to set priority and memory or CPU constraints. I suppose this could be a little project for you when you get bored one day. :)

Comment 4 Wegwerf 2016-11-21 20:07:46 UTC

I noticed that a fairly recent git master version allows you to run multiple rendering jobs concurrently now. After queueing multiple jobs, simply switch to the job queue tab, select a waiting job, and press the start button, and see that job starting and rendering. Sweet.

I don't know whether this feature has been present for a long time or nor, and it's not that obvious. But the devil in me made me click on start job for a waiting job and to my surprise I could run multiple rendering jobs in parallel. 

So I'm closing this one as fixed.