Syncing Audio and Video - 2 issues

Help/How To
1

Hello all,

I am trying to line up my video with audio recorded in audacity. I ran into two problems and just can’t find anything on it.

First, regardless of my ‘toggle snapping’ selection, I can’t place the audio track so it is lined up with the video. It’ll either snap to just before or just after where I want it. Why and how do I fix it?

Second, my audio file looks like it is shorter than the audio recorded by the camera (because I can’t align it, I can’t tell for sure). What would cause this? I recorded stereo audio in audacity and exported it as a .wav file. How do I fix this?

Help is appreciated.

2

Turn snapping off. You can either press the magnetic icon that is on the toolbar or use the shortcut key Ctrl+P to toggle snapping on and off.

3

As I said above, this happens no matter my snapping is set to on or off.

4

Did you try zooming in closer then seeing if you have better control?

5

Yes.

6

When something similar happens to me I move the video to the right, and then try to adjust the audio.
The duration of the audio may be different depending on the sample rate in Audacity and its subsequent export.

7

What’s the sampling rate of the wav file you exported out of Audacity?

8

looks like 44.1khz.

9

And what was the sampling rate of the audio recorded by the camera?

10

Having a hard time finding it, but according to the internet, the default is 48. So I’m guessing they need to be the same.

11

also, back to the snapping problem, the cursor (the vertical line in the time line) also snaps to specific points. I can’t figure out how to fix it, so I can’t line up my audio. It only seems to be able to work in intervals of 1 second.

Sometimes, when I get the audio lined up, Shotcut crashes before it snaps to.

12

In my copy of Audacity the default is 44100 Hz.

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S0f83iwAGH926×707 42.8 KB

When I import the audio embedded in an mp4 video (using the optional FFmpeg library in Audacity) the value is automatically set to 48kHz, but the default value returns to 44.1kHz when I open a new project.

To get the audio or video track information select the clip and click the Properties tab (or icon)

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pMPY8Aqp6B1920×1017 422 KB

In my example, the audio track embedded in the video (V1) is 48000 Hz.
The second audio track (A1) is an audio modified with a VST plug-in in an external program. To avoid problems the export was also a WAV audio at 48000 Hz.

The advance of the video track occurs (normally) frame by frame.
If this is not the case, you can share a screenshot in Shotcut with the video information.
Sometimes it can help to make the video suitable for editing, as shown below.

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4kk6KDrt2b1273×719 435 KB

13

Those are frames of video, not seconds, and the duration of a frame depends upon the frame rate. Shotcut does not offer audio position and duration more precise than the frame.

Please include an illustrated screenshot or screen recording in your next reply. Otherwise, no one understands your vague description.

15

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