Audio waveform not synched to video

[brian]

Your clips are probably variable frame rate. See the description here and the instructions to convert them:

Editing Variable Frame Rate Source Clips

Introduction Sometimes users report that Shotcut is not frame accurate. For example, they split a clip on a certain frame, but then later the split is not where they expected it. Or, they put a keyframe on a certain frame, but later the keyframe seems to be on a different frame. Also, sometimes people report that the audio and video out not in sync. Symptoms like these can be caused by Variable Frame Rate (VFR) source clips. Some users report that VFR clips work in Shotcut if the VFR is subtle.…