Bug 472029

Summary: Ultra slow import of video.
Product: [Applications] kdenlive Reporter: mark.giblin <mark.giblin>
Component: Project Bin & ImportAssignee: Jean-Baptiste Mardelle <jb>
Status: REPORTED ---    
Severity: normal CC: nicolas.fella
Priority: NOR    
Version First Reported In: unspecified   
Target Milestone: ---   
Platform: Microsoft Windows   
OS: Microsoft Windows   
Latest Commit: Version Fixed In:
Sentry Crash Report:

Description mark.giblin@yahoo.co.uk 2023-07-07 05:08:05 UTC 
SUMMARY
KDENLIVE v22.04.3 - when importing video into the editor, the audio takes a long time to become ready when its rendering the visual component of the audio wave display. This prevents the editing of video.

The PC is an Octa-core i7 - 9700 CPU @3GHz with 16GB of RAM with more than enough CPU's and CPU power to render video in minutes that would take an hour on my Linux MX install.


STEPS TO REPRODUCE
1. Load video in to KDENLIVE
2. 
3. 

OBSERVED RESULT
Audio takes a long time to become available. 
This prevents addition of other video clips to add to the editor until the audio has fully been parsed to output a display of an audio wave.

EXPECTED RESULT
Video to be able to be added and not have the editor stall

SOFTWARE/OS VERSIONS
Windows: 10
macOS: 
Linux/KDE Plasma: 
(available in About System)
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION
Audio should be parsed as an option and not a mandatory element, I typically render video with no audio yet I have to wait for the editor to render the audio waves when I don't need that to happen, it would be preferable to be asked if I require audio as well...
Comment 1 Jean-Baptiste Mardelle 2023-07-11 11:34:40 UTC 
It is a known issue that generating the audio waveform is currently slow in Kdenlive. One idea is to use a performant library like:
https://github.com/bbc/audiowaveform to generate the waveforms (it is approximately 3 times faster than our code), but it will take some time until this is implemented.

In the meantime, you can disable audio thumbnails for a project in:
Project > Project Settings > Thumbnails
Uncheck "Audio".

To disable thumbnails for new projects:
from the Kdenlive Settings > Timeline
Uncheck the "Enable for audio" option in Thumbnail.