Hi there,
I am looking for hints on how to improve the responsiveness of frame by frame playback in Kdenlive when using a jog wheel. I have a Shuttlepro v2 which generally works fine but especially when "jogging" backwards it feels laggy and seems to skip more than one frame at a time. Are there any tewaks in Kdenlive (for example regarding frame buffering) that could help with that? Or any codecs I should transcode my video to? In Kino the jog function feels much snappier which I suspect has to do with the fact that it transcodes everything to .dv video format (which is a frame by frame format from what I understand). But as .dv does not support 24p and audio-video-sync is critical for my use case using that is not an option.

Any hints on that are welcome.

Thanks! Stephan

Perhaps you can try working with proxy clips: http://userbase.kde.org/Kdenlive/Manual ... roxy_clips

I've used proxy clips in the past and I think they work quite well.

Recently I switched to transcoding all my clips to dnxhd. I find that the video quality (during editing) is better and seeking is just a little faster. The tradeoff is that it uses more disk space. But I don't mind that.

To transcode, from the project menu choose transcode and then select an appropriate dnxhd format.

Hi,
thanks a lot for your replies which led me to the conclusion that this is a question of using the right encoding and not of tuning Kdenlive itself. I finally came up with the solution of transcoding my videos to h264 without keyframes (ffmpeg -g 1) and this enhanced the Jog/frame-by-frame performance to what I wanted. Transcoding to dnxhd worked equally well but it used a lot more disk space than the h264 solution.

Stephan

stephans, can you please post the full set of parameters of your proxy profile?

these are my settings:

Code: Select all

-threads 8 -acodec copy -vcodec libx264 -g 1 -crf 20


The important thing here ist the "-g 1" which sets the keyframe interval to 1 meaning that every frame in the video will be a keyframe. As a result frame by frame performance especially when jumping frames backwards will be better.

beeing a total newbie to kdenlive - where do I find the jog wheel? Also, is there a way to do slow-motion play for preview (not as effect..)?

A jog wheel can be installed as a seperate bit of hardware (eg Contour ShuttlePro and Contour ShuttleXpress) or you can use the mouse wheel as a job wheel.
I don't think there is slow-mo as a preview option.

ttguy wrote:A jog wheel can be installed as a seperate bit of hardware (eg Contour ShuttlePro and Contour ShuttleXpress) or you can use the mouse wheel as a job wheel.
I don't think there is slow-mo as a preview option.

thanks.. the mouse wheel works fine for me. I was wondering if there is any software jog wheel like the widget that avidemux provides but with the mouse wheel I get finer control so the only thing missing is making it more obvious for beginners.