You might be wondering why you’d need to sync your audio to your video. Sometimes, the scratch track—the audio layer from raw video footage—isn’t always great quality, so many vloggers record externally with a microphone. Or, perhaps, you’re adding audio from a narration that isn’t from the raw footage.
They need to be synced to make your video look and sound great; you can learn how to do it in After Effects.
Before you can begin syncing the video and audio tracks together in After Effects, you should have a reference point in the audio and video footage. This can be in the form of a clapper board, hands clapping, or something loud you can see and hear well.
Your audio footage and video footage should both begin with the clap or loud noise mentioned earlier. This should be the case whenever you restart over. Every new take should begin with a loud noise and action visual.
If you’re editing pure film footage with audio, you might want to know how to sync audio to video in Adobe Premiere Pro—as well as learning how to do it in After Effects.
How to Sync Audio and Visual in After Effects
If you’ve filmed footage using your internal microphone in the camera, you’ll have a scratch track of audio from the camera. Cameras or phones don’t record the best quality audio; most vloggers or videographers will use an external microphone for creating videos.
Read our guide on what to look for when buying an external microphone. External microphones produce an external audio track, which is what you need to sync to the video.
To edit the footage, you first need to open it. Right-click in the Project panel and choose Import > File (Ctrl + I on Windows or Cmd + I on Mac). Select both your video file and the external audio file and click Open. Drag both files from the Project panel to the Timeline. Place the audio layer below the video footage layer.
Your footage layer includes a video track and an audio track from the camera’s microphone. If your video doesn’t have an internal audio track, for any reason, don’t lose hope. You can still sync your external audio to the video footage. You might not see the internal audio track right away, as it is hidden within the layer.
Step 2: Expand the Waveform
On the Timeline layers, expand the video track, then click Audio > Waveform. This allows you to see the waveforms of the internal audio. Where your claps happened, you’ll see large spikes in the waveforms—which will match the clapping you see in the video as you scrub through it.
The peaks of the waveforms don’t reach very high, as native audio doesn’t pick up the volume very well and often may capture background noise. You’ll see these issues within the waveform if you zoom in. We have a guide to improve audio quality in your videos.
Expand the layer for the external audio to see the waveforms, too. Depending on your microphone quality, you’ll notice a cleaner waveform and better sound by higher reaching peaks.
Step 3: Sync the Audio Tracks
Now you have both your internal audio and your external quality audio waveforms visible, it’s time to sync them. First, find the clap or noise reference in the video footage audio layer. Drag your Playback indicator to line up with the internal waveform’s peak.
Then, to sync them, it’s as simple as clicking and dragging your external audio layer left or right until the clap waveform looks in line with the above video audio layer. You probably can’t get it perfect just from eyeing it, but it’s a good start.
Move the Playback indicator to a point before the claps, and press Spacebar to preview the footage. You can tell if you need to sync the audio better or not. Press Spacebar to pause the preview.
You can also create reactions to visual elements by connecting them to audio beats in After Effects. While it’s similar to syncing audio and video, it produces a creative, fun result that can be used as a visual effect rather than just a necessity. Read our guide on how to make visual elements react to audio in After Effects.
Step 4: Sync With Precision
You can zoom in on the waveform layers to get a closer look and sync with perfection. Press + on your keyboard to zoom in. Press + multiple times to get a more detailed view of the waveforms.
Then click and drag the external audio layer until the sharp clap waveforms align on both audio layers. Dragging a layer while zoomed in will drag in small increments to ensure you don’t misalign anything. Press – to zoom out of the Timeline back to normal view.
Move the Playback indicator to the beginning and press Spacebar. You shouldn’t hear any echo or misaligned noise, but if you do, repeat this step until you don’t.
Step 5: Mute Internal Audio Track
Now that your high-quality audio is synced correctly to your video, you have no use for the low-quality camera audio. You can delete the layer by selecting the audio layer and pressing Backspace on your keyboard or right-clicking to choose Delete Layer.
For less of a permanent removal, you can select the Eye icon on the audio layer to mute it. This means that if for any reason you need to access the internal audio, you won’t have any issues recovering it, and you definitely wouldn’t have to re-sync it.
How to Sync Audio and Video Without Internal Audio
If you’ve followed along thus far, you’ve learned a lot about syncing audio and visual. But if you filmed your footage from a camera with no microphone, or the microphone doesn’t work, or you already discarded the internal audio track, then there is still a way to sync your video footage to external audio.
You won’t be able to sync to your internal audio since it doesn’t exist, but you can still use the principle of the clapper to sync visual-only footage to an audio track. The external audio will have the waveform and the video footage will have a visual action of the loud clap. If you didn’t use a visual clapper or hands to clap, this might be more difficult—but it’s not impossible.
Open the waveform of the external quality audio and zoom in by pressing + a few times. Drag the audio layer around where the clapping is in the video. Then click and drag the Playback indicator frame-by-frame until you see the exact frame where the clap happens.
This exact point of contact is where the noise would have been heard. Drag the audio layer so that the spike of the clap aligns with the playback indicator. Then move the indicator left and press Spacebar to preview. If it’s not quite right, go back and try again.
If you didn’t record a clapping noise, the process will be the same—but with a less obvious loud noise or visual component. You don’t have to sync the audio track at the beginning; since it’s all one track, you can sync from anywhere within the footage time. This could be helpful if you have a loud noise later in the footage that you can sync from.
You can easily sync audio to video whether you’re using an external microphone or using your iPhone to record audio.
Edit Your Videos With Better Precision
The process of syncing an audio track to your video footage is easy in After Effects. Even if you didn’t record with a clapper, it’s still possible to do. But to help yourself or your editors in the future, it’s always best to add a clap at the beginning of every new take in both filming and audio recording. Syncing high-quality audio to your video is a great way to make your videos look more professional.
Read the full article here