Bug 425416

SUMMARY
Audio playback is strange when sliding the cursor in the timeline window when the fps of the project is 59.94. When the project is 29.97 fps, then it works ok. 
When I'm searching for a parts of an audio clip, I click and hold the mouse cursor on the timeline, and that way I can play the audio faster of slower by sliding the cursor of the timeline. With v20.08.0, the audio is not played back correctly, there is a pitch or distortion in the audio.
The problem was present in the v18.12.2 when I was using mp3 files only. If I would extract audio to wav, then add it to the timeline, then the wav files are played back perfectly when I was sliding the timeline cursor.

STEPS TO REPRODUCE
1. Add an audio file to the project bin, then to the timeline.
2. Click and hold then move the cursor on the timeline to play the audio.
3. 

OBSERVED RESULT
You hear a pitch at every frame or I hear some distortion.


EXPECTED RESULT
The audio should be played back perfectly as you move the cursor.
For reference, open a project in kdenlive 18.12.2, add a wav file to the timeline, and play it back by sliding the cursor... it plays perfectly. For comparison add an mp3 file, and try to play it back: it is distorted.
(You might add an mp3 file first in v18.12.2, then extract audio to wav, and test the same file on the timeline.)

SOFTWARE/OS VERSIONS
Windows: Win10
macOS: 
Linux/KDE Plasma: 
(available in About System)
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION