Media Composer’s “Group Clips” feature is best suited for very simple multicamera shoots. As long as all of the cameras start and stop around the same time with no drop-outs in between, and as long as the timecode was shot time-of-day and jam-synced between cameras right before the shoot, you can easily make groups in a matter of seconds. In practice, however, it is rarely this simple. Cameramen with itchy trigger fingers start and stop recording every few seconds, independently of the other cameramen. This can cause the shots in a group to cycle through all of the available window positions in the four-frame display and force you to use the nine-frame view with smaller thumbnails. Maybe both cameras stopped shooting for a period of time, but you want to include footage after the break in your group. Sometimes production jam-syncs the cameras once in the morning, and by the afternoon they have drifted several frames out of sync. Luckily, there is a way to work around all of these issues and create convenient multigroups that contain all of your footage for a given scene and are perfectly in sync. Each camera can drop in and out, and the multigroup will automatically adjust and play smoothly throughout the duration of the footage. Put your thinking caps on – this tutorial is not for the faint of heart.

1. Make a sync map.

First you will need to lay out all of your footage in one long sequence (I like to do one sequence for each shooting day), with the master timecode of the sequence corresponding to the timecode of your cameras. With newer versions of Media Composer, this can be accomplished fairly simply. Select all of your clips that were shot by a single camera, and select “AutoSequence” from the “Bin” menu. Avid will automatically create a new sequence with master timecode that matches the source timecode, with the appropriate amount of filler in between the clips. After you do this for each camera, simply cut each sequence into a new multi-layered sequence (adding tracks and patching as necessary, so that each camera is on a different track) to create your day’s sync map. Be sure to cut in each camera sequence at the appropriate master timecode in your new multilayered sequence, as each camera most likely will have started at a different time of day.

For those of you still working on Meridiens, I feel your pain. Without AutoSequence, you’ll have to make your sync map manually or use a macro program such as QuicKeys to automate and speed up the process. Here’s how to do it manually: Make sure your sequence timecode is set to match whatever the cameras were shooting: drop-frame or non-drop-frame, and set the sequence starting timecode to match the timecode of the first frame of your first clip (Click on the record monitor and select “Get Sequence Info” from the “File” menu). The best way to form your sequence is to lay down your first and last clips of the day and add filler in between until you can match your last clip’s timecode with the sequence timecode. Remember, Avid still won’t let you add filler at the end of a sequence without a funky song and dance that I won’t get into here. From this point on, you can type the starting timecode of each clip into your record monitor, and the playhead will jump to that point in your sequence.

Then, you simply overwrite the filler with your entire master clip (Mark the clips beforehand to be sure you’re getting the whole thing). It is easiest to do this by first sorting your clips by timecode and then by tape name in your bin (your tape naming system should incorporate the date and tape number so that sorting by tape name will organize the shots by date and camera). Be sure to keep each camera on a separate video track (V1 for Cam A, V2 for Cam B, etc. – or however you like to do it). You can even rename each track in your timeline to reflect which camera it represents.

After you have finished this step (whether it be via AutoSequence or manually), you will have one long sequence that, if played in real-time from the beginning, will exactly recreate your shooting day. Pretty wild, huh?

2. Decide what needs grouping.

Once all your footage is laid out in a sequence, it is easy to quickly scope out what needs grouping. Any time there are overlapping clips, more than one camera was shooting simultaneously. Sometimes there will be single-camera shots, and sometimes you will have times where multiple cameras were shooting at the same time, but with different subjects in different locations, and the footage does not need to be grouped together. You can choose to either lift these parts out of your master sequence, or you can subclip the parts that you do want to group into their own smaller sequences (remember to reset the starting timecode to match the first frame of each). As a general rule, I usually don’t include any footage that editors wouldn’t need to cut back and forth between (b-roll, single-camera interviews, etc.), unless they specifically request it.

3. Check for timecode drift.



Pick a few points throughout your new sync map sequence, and try playing the audio from one camera with the video from another to see if they match perfectly. Watch your computer monitor, not the client monitor, as there is sometimes a minuscule delay, especially if the video is patched through a deck or DVD recorder. If audio was only recorded on one camera, you will have to check for sync by finding one distinctive-looking frame that appears in view of both cameras (a blink, a hand clap, a flash of light against an object in the background, etc.) and is not dependent on where each camera is placed (a person crossing behind another person, the first frame someone’s ear is visible, etc.). This can be a little tricky, especially if the cameras were pointed at different subjects.

4. Sync each camera to your base camera.

If there is some timecode drift, you will need to do the following. Pick one camera as your “base camera.” I like to use Cam A for simplicity. You must never move the clips of your base camera – lock its tracks for safety. Using red Segment Mode, slide each clip from your other cameras a couple frames at a time until they appear to be in sync. If production used a clap-board or other sync method, match the clips up using that method. Alternatively, if audio was recorded on both cameras, it is very helpful to turn on waveforms in your sequence and try to match up the clips using a sudden, loud burst of sound. In the picture below, notice that the sound that was recorded on both cameras can be matched up easily using its distinctive-looking waveform. I like to sync by soloing the audio from two different cameras (ideally one in each speaker so you can adjust the levels with your mixing board) and listening for echo. Then I simply slide my non-base camera a few frames at a time until I can no longer hear each camera’s audio independently, and they blend together perfectly. I find this to be easier and more accurate than trying to match audio to video.

5. Set Aux TC for your base camera.

Make sure your bin of master clips is set to display the field “Auxiliary TC 1.” Copy the “Start” timecode from each clip into its corresponding “Auxiliary TC1” field, but only for your base camera. The Auxiliary TC is the same as the Start time for this camera only, since you didn’t move any of these clips on your timeline.

6. Adjust the Aux TC for your non-base cameras.

Make sure your bin is still sorted by timecode and then by tape name. Pick a video track (except the one your base camera is on) and solo it (Apple-click or Ctrl-click on the monitor icon on the right side of the track button).

Make sure your Composer settings are set to stop on Head frames only.

Step through the edits of your sequence using the “Fast forward” command. Enter the sequence master timecode of the first frame after each edit into the “Auxiliary TC1” field of each non-base-camera clip. The clips should already be in chronological order in your bin, but you can “Match frame” and “Find bin” to highlight each clip if you want. It helps to have the timecode window displaying your sequence timecode in large numbers, rather than relying on the tiny numbers at the top of the record monitor. Your non-base cameras may already have identical timecode to your sequence master timecode, but they will be different if you had to manually change the sync. In the following example, V1 is my base camera, and V2 was out of sync by one frame. I would copy the number 16;55;24;09 into the “Auxiliary TC1” field of the clip that has a “Start” TC of 16;55;24;08.

7. Add edits at every camera start/stop point.

Make sure all of the tracks in your sequence are highlighted. Park your cursor on the first frame that any camera drops out or comes in (use the Apple or Control key to make the playhead snap to the correct frame). If you set your composer settings to “Ignore Track Selectors,” you can quickly jump to the next camera start/stop just by using “Fast Forward.” “Add edit” at each of these points throughout the entire sequence. The edit should go through all of the tracks. This will divide all of your clips into smaller pieces, where all the pieces on top of each other have equal duration.

8. Create subclips from your sequence.

Now you need to turn all of these pieces into subclips, which you will use to create your multigroup. The best way to do this is to step through your timeline again track by track (using the “Fast forward” key and “track solo” feature as before), and “Match frame” back to each master clip. This step is also a repetitive function that can be automated with QuicKeys. I recommend mapping your keyboard settings to have the following string of commands laid out in order on the number keys of your keyboard, or wherever you find most convenient.

Mark Clip

Go to In Point

Match Frame

Go to Out Point

Set Out Point

Subclip

Fast Forward



Turn on the “gang” button so that your master clips in the source monitor will move in tandem with your sequence. You should be able to rapidly hit buttons 1 through 6 to create each subclip. Then, simply click back in your timeline window (your bin will automatically be highlighted after creating a subclip) or hit “Apple-0” (or “Ctrl-0”), and then hit 7 until your playhead reaches another piece of media on that track. You cannot subclip a piece of filler, so skip over all of them (you will create a useless subsequence and hear an error sound if you try). Once you are done, you will have a bin full of hundreds (or even thousands) of subclips. The correct auxiliary timecode for each subclip should have transferred from its original master clip.

9. Double-check your subclips.

Sort your bin by tape name, and then by Auxiliary TC1. Also make sure that the heading “Duration” is showing. Glance down your bin and make sure that every clip that has the same Auxiliary TC also has the same duration. If you see an Aux TC that is off by a frame or two, or a duration that is too long or too short compared to the other cameras at a given Aux TC, you’ve made a mistake somewhere, either in your sequence or in assigning your Aux TC’s. It’s smart to make copies of your sequence after each step of the multigrouping process, so that if you do make a mistake, you can find it and fix it without undoing and redoing a ton of work. It’s important to consider that the sequence itself is literally just a map of the multigroup that you will be making, and the subclips themselves are what Avid uses to make the multigroup. Thus, if you change anything in your sequence after having made your subclips, you will need to make corresponding changes to the affected subclips, or remake them completely, or the changes will not stick.

10. Multigroup by Auxiliary TC1.

Once you’ve spot-checked for errors, select all your subclips, and click on “Multigroup” in the “Bin” menu. When it prompts you for a method, click “Auxiliary TC1.” Media Composer will create a number of groups (which you don’t really need) and one main multigroup. Watch through the multigroup, and make sure it plays through smoothly every time a camera starts or stops and that everything is in sync. Hopefully, if you did everything right, the multigroup will look great! Well worth the time and effort…

Note: This post was updated on 10/26/09 to clarify some points and add a couple of time-saving shortcuts using newer versions of Media Composer and Startly’s QuicKeys.