<p>Depends on <strong>how much time stretch is key</strong> to synchronize the shot. </p>

<ol>
<li><p>In order to increase the speed of the whole layer use the <strong>Time Stretch</strong> feature (<em>Right Click the Layer > Time > Time Stretch</em>) <em>Note: values below 100 increase the speed. Values above 110 often results in bad quality. To solve this, see motion calculation (3.)</em>   </p></li>
<li><p>To vary the speed of a layer, it's ok in most cases to use the standard <strong>Time Remapping</strong> feature (<em>Right Click the Layer > Time > Enable Time Remapping</em>) This makes it possible to keyframe the time/speed of your layer.</p></li>
<li><p>In some situations, especially for generating slow motion shots you need to <strong>calculate the motion in between the frames</strong> with <a href="http://en.wikipedia.org/wiki/Optical_flow" rel="nofollow noreferrer">optical flow</a> technology like <a href="http://www.revisionfx.com/products/twixtor/" rel="nofollow noreferrer">twixtor</a>. You can also play with <a href="https://github.com/slowmoVideo/slowmoVideo/" rel="nofollow noreferrer"><strong>SlomoVideo</strong></a> as an open source alternative. For further information, see this article: <a href="http://www.fxguide.com/featured/art_of_optical_flow/" rel="nofollow noreferrer">http://www.fxguide.com/featured/art_of_optical_flow/</a></p></li>
</ol>

<hr>

<p>For <strong>audio preview workflow</strong>, see: <a href="https://video.stackexchange.com/questions/15319/how-can-i-preview-with-audio-in-after-effects-and-be-able-to-pause-resume-the/15321#15321">How can I preview with audio in After Effects and be able to pause / resume the preview?</a></p>

CC BY-SA 3.0
2015-06-19T07:51:22.280Z
2015-06-19T09:50:09.283Z
2017-04-13T12:46:08.110Z
p2or
<ul>
<li><p>There's a video of a man, drawing something.</p></li>
<li><p>There's a violin symphony music.</p></li>
</ul>

<p>I want to sync the video, I mean the movements of hand with the symphony.</p>

<p>For example, I want the hand to move fast, when the music rate is fast, etc.</p>

<p>What I have to look for to achieve this?</p>

<after-effects><sync><motion><music>
How to sync motion and music in After Effects
Farzad
# How to sync motion and music in After Effects

(Asked by: username_0 on 2015-06-19)

* There's a video of a man, drawing something.
* There's a violin symphony music.

I want to sync the video, I mean the movements of hand with the symphony.

For example, I want the hand to move fast, when the music rate is fast, etc.

What I have to look for to achieve this?

**Tags:** after-effects, sync, motion, music


---

## 1 answers

### Answer by username_1 on 2015-06-19. Score: 2 | Accepted answer

Depends on **how much time stretch is key** to synchronize the shot.

1. In order to increase the speed of the whole layer use the **Time Stretch** feature (*Right Click the Layer > Time > Time Stretch*) *Note: values below 100 increase the speed. Values above 110 often results in bad quality. To solve this, see motion calculation (3.)*
2. To vary the speed of a layer, it's ok in most cases to use the standard **Time Remapping** feature (*Right Click the Layer > Time > Enable Time Remapping*) This makes it possible to keyframe the time/speed of your layer.
3. In some situations, especially for generating slow motion shots you need to **calculate the motion in between the frames** with [optical flow](http://en.wikipedia.org/wiki/Optical_flow) technology like [twixtor](http://www.revisionfx.com/products/twixtor/). You can also play with [**SlomoVideo**](https://github.com/slowmoVideo/slowmoVideo/) as an open source alternative. For further information, see this article: <http://www.fxguide.com/featured/art_of_optical_flow/>

---

For **audio preview workflow**, see: [How can I preview with audio in After Effects and be able to pause / resume the preview?](https://video.stackexchange.com/questions/15319/how-can-i-preview-with-audio-in-after-effects-and-be-able-to-pause-resume-the/15321#15321)


---

