Media Composer provides you with multiple methods to perform a trim to give you flexibility, depending on your personal preference, or for what will work best at a particular moment.
Trim Keys (Interface) – the Trim Keys can be accessed on the interface when in Trim Mode (see the next screenshot). The only caution here is not to click on the Step Forward/Reverse keys by mistake, since they do not trim and will exit you from Trim Mode. You can, however, use Fast Forward and Rewind to jump from transition to transition and remain in Trim Mode.
Trim Keys (Keyboard) – found on the keyboard in the bottom-right corner. By default, they are on the keys M, comma, period, and forward slash. It's important to note that the Trim Keys on the keyboard also have a function even when you're not in Trim Mode. Specifically, they Slip segments (discussed in this appendix in the section titled Slipping Outside of Trim Mode).
Numeric Keypad – you can type in a specific number of seconds and frames (or feet and frames if you're in a film project) that you'd like to trim. When you do this, the two purple trim counter displays will be replaced by a value entry box. The important thing to know here is that Media Composer needs to know which direction you want the Trim Roller(s) to trim. To instruct it to trim to the left, you type a minus sign before entering a numeric value and pressing the Enter key. To trim to the right, type a plus sign before entering a numeric value and pressing the Enter key. Here are two examples:
In the image on the left, the Trim Rollers are on the A-Side (left-hand side) shot of the transition. To make this shot longer by 48 frames, using the numeric keypad, you'd type in +48, then press the Enter key. The + tells Media Composer to trim to the right (in a positive direction). In the image on the right, the Trim Rollers are on the B-Side shot of the transition. To make this shot longer by60 frames, using the numeric keypad, you'd type in –60, then press the Enter key. The – tells Media Composer to trim to the left (in a negative direction). What can be confusing is that the plus and minus signs are not telling Media Composer to add or subtract. They are i
nstead telling it which direction to perform the trim.
A bonus feature of using the Numeric Key Pad is that after you have used it to make a trim, the value you entered remains in its memory. So, if you want to trim by that same amount in the future, just press the Enter key. The value remains in the memory until you type in a new value.
JKL Trimming – also referred to as Three Button Trimming or Dynamic Trimming. This is one of the most (if not the most) useful editing features. If you haven't used it before, give it a try. The more you use it, the more comfortable with it you'll become. And once you're comfortable with it, you'll find yourself trimming faster and more intuitively than ever. For more information on all that JKL can do, see the Moving Around: Methods and tips section in Appendix A, Additional Tips, Tricks, and Explanations. For a discussion on remapping the JKL functions, see the Mapping buttons and menu selections recipe in Chapter 2, Customizing Your Work Environment.
Dragging in the Timeline – you can click to grab the Trim Rollers directly in the Timeline and drag left or right in order to perform a trim. The addition of the Smart Tool increased these abilities (more information about the Smart Tool is later in this appendix). The one issue to be aware of when grabbing Trim Rollers is making sure that you are indeed grabbing the roller and not mistakenly instructing Media Composer to change the Trim Roller configuration to the opposite side. The key to this is to pay attention and make sure that the Trim Roller in the Timeline and your cursor's trim icon indicate the same side of the transition. Following are two examples:
Screenshot on the left: If the goal is to trim the A-Side (left-hand side) shot at the transition, then the picture on the left is correct. It's correct because the cursor icon has its little piece of film extending out of it pointing to the left (facing to the A-Side) while it's hovering over a Trim Roller in the Timeline which is also on the A-Side. In this situation, clicking and holding the mouse button and then dragging will indeed trim the A-Side shot.
Screenshot on the left: If the goal is to trim the A-Side shot at the transition, then the picture on the right is not correct. It's incorrect because the Trim Rollers in the Timeline are on the A-Side, but the cursor icon has its little piece of film extending out of it pointing to the B-Side. Clicking the mouse button in this situation would tell Media Composer to move the Trim Rollers to the B-Side.
The exception to the previous rule is Double Roller Trim. In this case, it doesn't matter which direction your cursor's piece of film extends when you grab. In other words, when you're in Double Roller Trim, you can grab the rollers when the cursor icon faces either direction. Why? The reason it doesn't display a Double Roller icon is that when you're using the Shift + click method to configure the Trim Rollers, you need the cursor icon to display as either A-Side or B-Side (the Shift + click method is discussed earlier in this appendix in the the Enabling and configuring the Trim tools recipe).
Trim while Looping – when you enter Trim Mode, the Play button automatically transforms into the Play Loop function wherever it's located (for example, on the Space bar). What's sometimes useful is that when you are looping the transition you can also trim. To be clear, you must have pressed the Play Loop button and the loop must be in progress for the following abilities to work:
Use the Trim Keys on the keyboard (by default on the M, comma, period, and forward slash keys) – while the loop is in progress, tap any of the Trim Keys on the keyboard as many times as you like. For example, to trim three frames to the right while the looping is in progress, you'd tap the period key three times in quick succession (tap, tap, tap). It may take a moment for the trim to actually take effect, so you may need to let the loop complete its cycle to see the result. This is a particularly useful ability when you need to trim just one or two frames at a time.
Mark In or Mark Out – while the loop is in progress, press either the Mark In or Mark Out button on the keyboard (it doesn't matter which) and the segment will be trimmed to the point at which you pressed the In or Out Mark.
Isolate the Loop – when using the Play Loop trimming tricks previously, you may find it helpful to change the loop from playing both the A-Side and the B-Side to only playing one or the other side. While the loop is in progress, press the Go To Mark In button on the keyboard (by default on the letter Q key). The loop will then occur only on the A-Side. While it's looping just the A-Side, if you press the Go To Mark In button (Q key) a second time, the loop will return to looping both sides. The same behavior is true for the Go To Mark Out button (by default on the letter W key), except that it loops only the B-Side of the transition.