As a test, you can add the “Audio Waveform Visualization” filter to the clip. Then, you can step through the frames to see when the audio arrives. On my system, it looks like the audio is 4 frames late.
Are you able to correct this 4-frame audio delay? I don’t know where this discrepancy creeps it, either in the original or YouTube or the YouTube video file downloader.
There appears to be some bug within Shotcut though. I can duplicate what you created @brian in your screenshot, where there is no sound in the waveform depending on how fast/slow I scroll up/down in frames.
It was enabled. Disabled has the same result.
This is a Source only project.
Video Mode is HD1080p, 60fps. (Sorry for not stating that earlier)
The video is on an internal HDD (7200 rpm) and Shotcut is on an internal SSD.
Project file and settings all SSD.
I have yet to test the video file on an SSD. Shotcut application log.txt (54.7 KB)
I do not think the drive type will make a difference.
You are probably experiencing seeking inconsistencies. I tried, but did not experience that myself. I think that seeking in mp4 files is pretty good, but not perfect. Have you tried the second link (ProRes)? When I tested it, the audio/video sync was perfect.
I get 2 frames of audio delay if the keyboard is advancing/retarding one frame per keypress.
The VU meters are very handy in spotting the audio.
A keyboard command which shifts the currently-selected track by one frame in either direction asynchronously from the associated audio/video track would be handy and steadier than the mouse.