How to Adjust Video Speed to Match Audio Length in Shotcut?

Help/How To
1

I have a piece of music and a video clip with different durations.

How can I adjust the video speed to make the video’s length match the audio’s length?

Is there a more convenient method that doesn’t require manually calculating and adjusting the speed ratio?

2

Not that I know of :frowning:, except time remapping.

I believe this is rather a good suggestion, show time after typing in the speed before apply, and also, adjust by time, type in the exact time to decrease or increase the speed according to that.

3

There is already a suggestion to add time-stretching on the timeline: an option to adjust speed instead of trim when dragging the edges of a clip.

To make calculation easier use Settings > Time Format > Frames. Then, simply divide the durations shown in the clips’ tooltips. Many OS search functions have a handy keyboard shortcut and builtin calculator, for example the Windows key or command+space for Spotlight on macOS. Simply open the search and type in an expression like 88/165

4

Nice joke, who uses that :skull::wink:
Without powertoys, I highly doubt you can do anything like that. It works, but not everytime.

5

I didn’t know earlier. Thanks for letting me know :+1:t2:

Atleast this is actually useful, might be worth it.

6

When I change the speed, I don’t see the time change unless I apply the change in the properties.

Looking forward to this feature!

Useful tips!

7

Maybe I arrive a bit late to the party, but there are ways to slow down or speed up a video clip to any duration you want, without having to guess or calculate the value of the speed ratio.

To slow down a clip to an exact duration

  • Find the exact length of the Audio clip. Take a note of it
  • Select the Video clip.
  • Add a Time Remap filter (convert to Edit Friendly, if prompted)
  • Go to the Properties panel.
  • Adjust the Duration to about 1 second longer than the length of the Audio clip.
  • Click on Apply.
  • In the Timeline, extend the Video clip to make it as long as the Audio clip.
  • Go back to the Time Remap filter.
  • In the Keyframes panel, use the Seek Forwards button to move the Playhead to the last frame of the video clip.
  • Add a keyframe at that position.
  • Select the middle keyframe, and delete it.

The Video clip is now slowed down to match the duration of the Audio clip.

To speed up a clip to an exact duration

  • Add a Time Remap filter to the Video clip (convert to Edit Friendly, if prompted).
  • Move the Playhead to the last frame of the Audio clip.
  • Add a keyframe at that position.
  • In the filters panel, click on the right arrow button.
  • Set the Speed value to 0.
  • In the Timeline, move the Playhead to the last frame of the Audio clip and trim the end of the Video clip.

The Video clip is now sped up to match the duration of the Audio clip.

3 Likes
8

That was just a suggestion, it’s not there in shotcut right now.

9

Thank you for your detailed response and the method you provided.

This is a great method!

But if the video clip I want to edit is trimmed from another master clip, then the duration refers to the master clip, not the trimmed sub-clip.

I don’t know how to adjust the current video’s duration in the timeline when there are other video clips present.

Dragging will automatically connect to the subsequent frames instead of repeating the last frame of the current sub-clip.

If I adjust the speed of the current video, then the Time Remap filter cannot be used.

10

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