The DSLR Filmmaker’s Handbook: Real-World Production Techniques, Second Edition (2015)
Chapter 11. Audio Crash Course
You have made it through your shoot, and you have drives with extra backups lying around. It is time to start assembling your workflow for post-production.
Whether you have converted your footage or are working in an editing program that lets you edit native files, now is the time to sync up your footage. This is a critical and potentially time-consuming process. You have to do it right from the start, or there is a good chance you will have to redo it later.
Syncing Your Audio and Video
One way to sync your audio and video files is manually syncing them. This time-honored tradition stretches back to the invention of sound for movies. This is a pretty simple yet time-consuming way to sync your footage. You just find the start of each scene where you used a clapboard (or your hands), find the frame where the clapboard first closes, and find the audio spike on your audio waveform. Line them up, and you are finished (Figure 11-1). Considering you will have hundreds if not thousands of shots, you can see how this may not be the most efficient way to work.
Figure 11-1: Working in Premiere Pro and syncing audio with video clips
Before you start syncing your audio, you must first make sure your timeline or project file is set up properly so you don’t have issues later down the road. If you have your settings for your project/sequence wrong from the start, then you may end up having drift audio issues where the audio slowly loses sync with the video. Also, if you try to sync your audio after a rough edit, it is infinitely more difficult and time consuming than doing it from the get-go.
Setting Up Your Editing Timelines Properly
The most likely explanation for audio sync issues is that your project has not been set up properly or that your audio recorder wasn’t set up properly from the beginning. More specifically, if you shoot with NTSC frame rates (like 23.98 or 29.97) and have your project set up with non-NTSC frame rates (like 25 or 30), then you will have troubles with your audio drifting out of sync over the course of longer clips.
Changing the Speed of the Audio Clips
You have the option of changing the speed of your audio clips, which in theory will help you correct for the difference between 30 fps and 29.97 fps. The best reason to not do this is you would be resampling your audio twice. This would cause a quality drop right up front and can cause more issues as you move through post. Just because you can speed up or slow down clips from 99.9 percent or 100.1 percent and sync them doesn’t mean you should. The best practice always is to set things up right to begin with and deal with issues only at the last few steps of post, not up front.
Setting Up Your NLE Properly
In a nonlinear editor (NLE), do these two key things to avoid sync problems:
· Never mix NTSC and non-NTSC footage in one sequence. Use Twixtor or Compressor to conform your clips to a common frame rate.
· Utilize an Easy Setup—an option in Final Cut Pro—that automatically matches your properties and frame rate.
To use an Easy Setup in Final Cut Pro, before you start importing your clips and setting up your projects and sequences, take the following steps. This will reduce troubles and prevent having to re-create a lot of your work at a later point.
1. Close all open projects.
2. From the Final Cut Pro menu, choose an Easy Setup that matches the frame rate of your video clips. If you can’t find an exact match, pick one with the same NTSC properties as your video. For example, if you are working with 30.00 fps material from a Canon 5D, then choose an Easy Setup with a 25 fps frame rate.
3. Close Final Cut and restart.
4. Create a new project and import your footage.
5. Add your clips to the timeline (do this first so that Final Cut will autoconform the sequence if the settings are different from your clip).
Just like most things in filmmaking, it is best to check and double-check before you start. It is much harder to correct and change course after you have started down the path in one direction. Test your audio and make sure it is working before you jump in and start syncing hundreds or thousands of clips only to have to redo them later.
Syncing Footage Directly in Your NLE
You should begin by syncing your footage in your nonlinear editor of choice. We will look at both FCPX and Premiere Pro CC and how you can quickly sync your audio and video in those programs.
Final Cut Pro X
Follow these steps to sync your footage in Final Cut Pro X:
1. Make sure you have your audio and video clips in a bin (Figure 11-2).
Figure 11-2: Make sure you have all your video and audio clips imported into Final Cut.
2. Select the video file and the audio file by right-clicking both files (Figure 11-3).
Figure 11-3: Select the audio and video files you want to synchronize.
3. Choose Clip ⇒ Synchronize Clips (Figure 11-4).
You will get a dialog box asking you to name the clip you are creating (Figure 11-5).
Figure 11-4: Choose Synchronize Clips to start the process.
Figure 11-5: Name the new file you are creating anything you want.
Your new synchronized clip will appear in your clip window with all your other source clips (Figure 11-6).
Figure 11-6: The synchronized clip will be added to your project bin.
4. You can then open the clip in the timeline and listen to the synced clip (Figure 11-7).
Figure 11-7: Add the clip to your timeline and you can begin your edit.
Premiere Pro CC
Follow these steps to sync your footage in Premiere Pro CC:
1. Import your audio and video files into your project (Figure 11-8).
Figure 11-8: Your imported clips will be in your project bin.
2. Click both the audio and video files so both are selected (Figure 11-9).
Figure 11-9: Make sure both clips are selected/highlighted.
3. Right-click (Control+click on the Mac) and select Merge Clips from the drop-down menu (Figure 11-10).
Figure 11-10: Select Merge Clips from the menu.
4. A dialog box will appear with options for you to merge the clips (Figure 11-11).
5. Under Synchronize Point, select Audio to sync the clips via the audio track (Figure 11-12).
Figure 11-11: You can see the dialog box with all your options for merging the clips.
Figure 11-12: If you are merging the clips based on the audio tracks, make sure to select the Audio button in the Synchronize Point area.
6. If you want to remove the rough audio from your original video file, you can select Remove Audio From AV Clip and the resulting file will have only the newly synced audio from your external recorder (Figure 11-13).
A new merged clip will appear in your project bin (Figure 11-14).
Figure 11-13: If you don’t want both the new and old audio attached to the video file, you can click Remove Audio From AV Clip.
Figure 11-14: The merged clip will appear in the project bin.
7. You can then right-click (Control+click on the Mac) the new merged clip and select New Sequence From Clip (Figure 11-15).
Figure 11-15: Select New Sequence From Clip to add the new merged clip to the timeline.
You will now have the merged audio and video clip on the timeline ready for you to edit (Figure 11-16).
Figure 11-16: You are ready to edit.
Syncing Automatically with PluralEyes
Another way to sync audio is to let a software program automate the syncing process. The most popular today is a plug-in called PluralEyes made by Red Giant Software (www.redgiant.com). This plug-in sells for $199 full retail, $79 to upgrade from a previous version, or $99 for an academic license. PluralEyes works with Final Cut Pro, Premiere Pro, and Avid.
PluralEyes works by reading the audio files in the video files from the camera and compares them to the audio files off your external recorder. It matches up the waveforms and syncs them automatically. This is why it is critical if you choose a dual-audio system to get a good, strong audio signal into your camera. If you are shooting a scene with two cameras and one is close to the actors and the other is much farther away, this could cause problems. If the audio signal is too weak, PluralEyes can’t match the waveforms, and you will be stuck doing all these takes manually. Trust us; it is much easier to make sure to get a strong audio feed into the camera than to touch a lot of your scenes manually in post.
To sync your audio from your external device to your video clips, follow these steps:
1. Open PluralEyes.
2. Import your audio and video files into PluralEyes (Figure 11-17).
Figure 11-17: Version 3 of PluralEyes is a stand-alone program and works outside your NLE of choice.
3. Once the files have been processed, you will see the audio and video files on the timeline (Figure 11-18).
Figure 11-18: All the audio and video files will be aligned to the start but they are not yet synced.
4. You can click the Synchronize button above the video preview window or you can select an option from the Sync drop-down menu to begin the syncing process (Figure 11-19).
Figure 11-19: Click Sync and let PluralEyes do all the work for you.
If the syncing works, you will see the files line up and colored green (Figure 11-20). This process can take a long time depending on the number of files you are trying to sync and how strong your reference audio is on your raw movie files.
Figure 11-20: Anything labeled in green is good and ready to edit.
When you have finished running PluralEyes, there may be some files that can’t be synced for a number of reasons. This can be because you placed movie files where there was no reference audio or because the reference audio was too bad for the waveforms to be matched up. Any non-synced files will appear red and not green (Figure 11-21).
Figure 11-21: Clips labeled in red are not synced and not ready to edit.
Look through the red files and determine whether they were supposed to sync or whether you had extra files in your sequence. Sometimes you will find you had extra video clips for a scene they weren’t supposed to be in or MOS video clips that you shot without audio. Just make sure at this point that all video clips that need to have synced sound are synced, and categorize MOS clips that need to be moved to another project/bin.
If you shot with multiple cameras, no worries because PluralEyes can sync your audio and multiple camera sources all at the same time. You would follow the previous steps but you would need to create a separate video track for each camera.
Troubleshooting Out-of-Sync Sound
Sometimes your synced audio/video clip starts out matching, but the longer you watch, the more it drifts out of sync. This is not a new problem, nor is it unique to DSLR filmmaking. However, more and more people who shoot on DSLR cameras are doing more of the post work themselves, and a lack of knowledge of what is going on behind the scenes can needlessly create headaches such as this.
1. Dropped Frames When using traditional video tape or codecs such as AVCHD, when you log in your footage, you actually capture the video instead of transferring it. At times during this process you can have dropped frames. Losing several frames of your video changes where the frames that follow line up with the audio track. Dropping frames in more than one place during capture compounds the audio drift. This is not the case with DSLR cameras, and we have yet to hear of a camera dropping frames while recording; however, you can never rule things out completely. If you are an adventuresome type who will install hardware hacks and push the cameras, you may come across this.
2. Recording Device Not Accurate As you have read in this book, the Zoom H4n is the recommended audio capture device for the dual system if you cannot hire a professional audio person or rent a 744T digital recording device. With that said, there are many other audio recorders on the market. There is a predecessor to the Zoom H4n called the H4; it is not as accurate as the H4n and is more prone to syncing problems in post. Other devices, such as the M-Audio Microtrack, are not as reliable either. Most of these audio-capture devices have an internal clock that helps them keep track of time and sync. Some models are not as accurate as you need for syncing people speaking.
3. It is best to do your research and make sure the audio device you are going to record with is accurate for syncing sound and can be changed to support the actual frame rate that you are shooting in the camera.
4. Frame Rates Many of the current DSLR cameras can shoot in a variety of frame rates, including 30, 29.97, 25, 24, 23.976, 60/50, and 59.97 fps. When so many different frame rates are available and you have two different recording systems, it is very easy to run into trouble.
The funny thing is that rarely is it the video or audio files that are the cause of most of the problems. Most problems arise from how you set up your editing program.
Automated Dialogue Replacement and Sound Effects
On any film there is no way to avoid at least one automated dialogue replacement (ADR) scene. Here are some quick tips and a step-by-step guide to ADRing a bad audio scene.
In the field, you need to make sure to capture or have your audio engineer capture room tone. This is a two- to three-minute audio recording of the ambient noise of your location. This is the foundation for all ADR work in post. If you don’t get this on location, you can expect many extra hours or days of post work to get close to matching but may never match the audio that surrounds the new ADR scene.
1. Open your project with the scene you need to ADR (Figure 11-22).
Figure 11-22: Open the project and sequence you want to do your ADR work on.
2. Open your sequence and delete the original audio from the timeline (Figure 11-23). You may need to unlink your video and audio files before you can delete just the audio files. If you didn’t record with any audio (meaning you turned off the audio recording function on your camera), you can skip this step.
Figure 11-23: You may need to unlink your video and audio files before you can delete just the audio files.
3. Select your room tone audio file that you recorded in that location (Figure 11-24).
4. Lay down the room tone audio in the timeline to fit the exact amount of time you need to fill (Figure 11-25). (If you need longer than the two to three minutes, you can just duplicate the clip over and over until you fill the total time you need filled. The reason you record three minutes of audio is that humans can detect audio looping if the loops are too short. If you have two to three minutes, you can just keep copying the file, and you are good to go.)
Figure 11-24: In this bin, the room tone is labeled AMBIENCET03.WAV.
Figure 11-25: Lay down the room tone track as your baseline.
5. Add additional audio tracks (Figure 11-26) for the number of items you will be using to rebuild the audio.
Figure 11-26: In Final Cut Pro on the Mac, you can simply Control+click under the audio files to add more tracks.
6. Lay your voice audio files to the video on their own audio track (Figure 11-27). Add each ADR track on its own track to keep each audio level separate and allow for maximum control during the edit.
Figure 11-27: Add your voice-over tracks under the ADR audio tracks.
7. Lay down your sound effects in their own track, if you need any (Figure 11-28).
Figure 11-28: Add the sound effects to their own track under the room tone and ADR tracks.
8. Lay down your music track (Figure 11-29).
Figure 11-29: Continue adding the score to its own track(s) under the other audio tracks.
This will help you rebuild any scene where you recorded bad audio or if some external noise pollution wrecked the perfect take. Just a little time and planning can make for a very smooth and successful ADR session.
Now that you have your field audio synced and your ADR done, you want to place in any sound effects for your film.
Let’s not forget about one of the most important parts about any video—the music! In many cases this will be the reason your film or video is loved and shared or not. Bad music will kill all the other hard work you have done. Great music can transform what you have done to something you only dreamed of.
There are a few ways you can go about getting great music. Here are some resources:
You can find many other royalty-free music sites on the Web, so take a look around. The big thing with royalty-free music is the amount of time it takes you to comb through their libraries. Some sites have so many tracks you could search as your full-time job. Please note that “royalty-free” does not mean they are free, but rather they don’t have copyright issues associated with them so you can pay to use them in your videos. You may be able to find some royalty-free music that is indeed free, but please don’t get confused by the term.
Also available are services where you provide a song or a piece of music you like and they will try to pull tracks that are close. Sometimes websites offer this service, but other times they are part of a music licensing company that works with other companies that buy a yearly subscription to their libraries, and they help them find the best music for projects throughout the year.
My favorite way to get great music is to work with a composer and have them score the film for me. In general, this is a risky way to go because it tends to be expensive or the quality you get back for your cost may be low. The way I have had success is to find music from major motion pictures that I like and give me the feel I want. Then I find a composer whose work I like and play that for them. If they feel the same thing I do, I go ahead and work out a price and hire them. For the most part I have been blown away at the quality of work I have gotten back, and I get compliments all the time on the music from my projects. It takes more work and requires a longer post-production schedule, so this is definitely not for everyone.