Hi, I have just downloaded Kdenlive Version 19.12.0 and it is really the best ever!

Unfortunately though, it appears the timeline preview files do not appear to be used for playback and scrubbing.

I have created the preview zones in the normal way and the bar changes red, orange, green in 1 sec. segments as I would expect. The preview files are being created in the project cache folder and I can play them back using VLC etc.

However, if I try to scrub or play in Kdenlive through a transition or with complex filters then the playback is really jumpy. In fact, if I select "Disable Timeline Preview" in the timeline drop down, then the playback FPS is the same as with preview rendering enabled.

This appears to happen on both Windows 10 and Ubuntu 19.10. It is especially noticeable when working with 4K, but also happens on 1080p.

I am using proxy clips (MPEG).

The only thing that I have noticed is that only MPEG and ProRes options work for the preview rendering under Windows, and the MPEG clips render as .avi files rather than .mp3 or .mkt that I would expect.

Is there a new setting / configuration option that I need to use for the preview render to work correctly?

Many thanks!

I'm not sure but you can try with changing the track compositing. See here: https://userbase.kde.org/Kdenlive/Manua ... e_Tool_Bar

Thank you for the suggestion.

I didn't know about this setting and it certainly improves performance with title overlays, but unfortunately doesn't have much impact on effects such as Lift/Gamma/Gain.

It really seems to me that Kdenlive isn't even trying to play the preview render files, just using the proxy versions and rendering on the fly.