Bug 506761

SUMMARY

When using a speed greater than 1, like 2 for instance, audio sounds glitchy.

It was flagged as a bug by different people:
https://bugs.kde.org/show_bug.cgi?id=464558
https://bugs.kde.org/show_bug.cgi?id=487976

And is preventing people from doing proper editing of long content since at least 2020:
https://www.reddit.com/r/kdenlive/comments/k17ze6/audio_inintelligible_whan_speeding_up_playback/ 

It is even discussed in Kdenlive forum
https://discuss.kde.org/t/playing-fast-forward-on-kdenlive-is-laggy-pc-not-powerful-enough/16505

I also thought it was a bug, but after some digging, I don't think it is. I think it's an implementation decision, and that's why I'm now opening this Feature Request.

For reference: https://en.wikipedia.org/wiki/Scrubbing_%28audio%29

I think right now Kdenlive is using Cut-and-paste audio scrubbing, and I think it would be better to offer the possibility to use a Timeline stretching implementation of audio scrubbing. It is a wide spread feature in modern video editors, a seemingly ubiquitous one. So much so that users can't spot that the feature is missing and just think that there is a bug.

I know that Kdenlive is using MLT with SDL or RtAudio, and I didn't find any way to select an implementation of audio scrubbing there, it's just on or off. So I don't know if that's a feature that we should ask to MLT, SDL, RTaudio etc, or if Kdenlive could implement it on their side. Anyways, it's a much needed feature for a modern video editor, and I think it should be considered as a priority since its addition could benefit Kdenlive and its user greatly. 

Note: I wanted to open this feature request in Kde Invent, but I saw this prompt: "Please note that all bug reports and feature requests should be filed on bugs.kde.org and should never be raised here." That's why I'm opening this feature request here.