Syncing Audio & Video – Part 1 | Making the Guide Track!
When I was a kid growing up I wanted to make trailers for movies. Sometimes it seems like the trailer is better than the movies themselves. I figured, having AE and Ableton, why not try to make some? I have already started with a strictly sound fx and tonal piece, which you can check out here. You can also check out how I made the deep brass fx hit featured in the trailer in this tutorial as well.
This second project is a bit more ambitious. Here I wanted to add a full track of music scored to a video game preview. I chose the teaser trailer for Call of Duty: Ghosts. It was short, and featured quick cutting that would go well with the Japanese Taiko Percussion Live pack I had recently downloaded from Ableton.com.
This is what we will be creating. Or at least, I will show you how to sync the video with the percussive hits 😉
The first thing I decided to do was determine the original BPM of the original score. That was quite easy inside Ableton Live. Loading the video and the audio from the original clip I simply used the BPM finding technique described here. It turned out that the video was extremely close to 70 BPM. But, not quite.
The reason for that is the frame rate of the clip. When I loaded the clip into After Effects I saw that the frame rate for this particular clip was 23.976 per second. What I need to do now was start making my music so I chose a BPM closest to the original for ease.
23.976 x 3 = 71.928
Since Live only allows accuracy to two decimal points I dropped the 8 and rounded the two to give me 71.93 for my project BPM. This allows me to syncing the picture with the music down to the frame.
The next bright idea I had was warping the video to an outline (guide) audio track. This way I could preview the video in live while producing the score in order to make the music flow perfectly with the picture. Also, the more complicated the music the more messy the audio wavs. Making something simple with hits leaves the wav file clean and easy to sink to.
They way I made the outline track is demonstrated in the video below. Essentially I used different sounds; one to mark the one drop of every bar, a second for the 1/2 notes, and a third for the 1/8 notes. The sounds themselves are not important, as inside AE we will only be using the visual cues for the syncing process. I found that works quickest because I wouldn’t need to ram preview every couple of seconds.
Once you get your loop all set up like described above it might be a good idea to record it into a new audio channel to make sure the visual cues will work. It should look something like this if done in Ableton Live.
Once everything looks nice, like it does above in audio channel #2, we want to export that clip. In Live make sure the clip is highlighted completely for exporting. Go to File > Export Audio / Video . When the window propagates make sure to check a couple things: Render as Loop = On & Convert to Mono = ON. Select the correct audio channel from the drop down menu at the top and render. Quickly open the newly created audio file to make sure it looks like the one below.
You can download the one I made from the box above the video tutorial featured at the bottom of this article.
All you need to do from now on is bring the final audio file into Live and adjust the project BPM to whatever is necessary according to a multiple of your film’s frame rate. Then loop the audio clip so that it is longer than the AE project. In my case 2 minutes will do.
Don’t forget to check out the other tutorials in this series:
- Part 1: Making a Guide Track (ableton)
- Part 2: First Film Sync (after effects)
- Part 3: Music Idea Outline (ableton)