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Edit Suite: How to Use Time Code

Contrary to what you might think, time codes frame accuracy makes it easier and faster to edit video.

Contrary to what you might think, time codes frame accuracy makes it easier and faster to edit video.

So youre finally going to do it--you think you want to make an investment in equipment that can generate and read time code. Before you lies the world of time code editing. As you get ready to call the discount video supply houses, it suddenly occurs to you that you have no idea how to use time code. And that leads you to ask why you need it.

The Cons of the Video Tape Counter
Why cant you simply use the tape counter to determine your edit? After all, you can use the jog/shuttle on your edit controller to find the frame you want to end with. That much is true. However, relying on the tape counter for positioning your tape does not guarantee frame-accurate editing. Rather than ending on a specific frame, youll end somewhere pretty close to that specific frame.

Here's something else to think about: what happens if you make your edit, edit for another hour, and then want to use that same frame or sequence of video later on in your program? You would have to search manually through your raw footage for that same shot. Even when you find it, there's no way to be sure its the same frame you used before because in the course of your editing, you had to reset the tape counter.

Time code, by contrast, is recorded directly onto the tape--in some cases, even embedded into the video signal itself. This means you can make note of every video sequence as a range of time code, and return to that exact sequence time and again throughout the course of your edit session.

Working with time code is the next step toward making your programs more polished and professional in appearance. You can edit without it, but time code facilitates editing techniques that are otherwise difficult. Why? Because it gives you access to very accurate edits. Youll be able to number every frame of video individually and go back to each frame time and again simply by searching for its unique time code stamp. No longer will you have to guess at where you want your transitions to take place, or "eyeball" matching video. Your audio can go into and out of sync without worry. All because you can keep your video frames numbered, and because your edit controller and decks will be able to read the time code stamp on every frame.

Time Code Equipment
For an in-depth look at what time code is, see, Time Code is on Your Side in the September 1997 issue of Videomaker. For this discussion, you need only know that time code comes in a number of different varieties. Some types are peculiar to particular video formats, like S-VHS or Hi8. Regardless of the type you decide to use, you need to have some equipment to generate it, decks that can record it and/or an edit controller that can read it.

Time code is of no use to you unless you can record it onto tape. Fortunately, many camcorders lay down some sort of time code when they are recording. On some S-VHS camcorders, this time code is usually called VITC, or "vertical interval time code." VITC fills the physical spaces on the videotape that occur between frames of video (the "vertical blanking interval"). Because it is an integral part of the video signal, all you have to do to get VITC onto a tape is to shoot video with a camcorder equipped to write it. Unfortunately, no consumer camcorders sold in the U.S. come so equipped. Only professional camers sport it.

You can also get time code onto your tape after youve shot your footage. In the S-VHS family, this kind of time code is generically called LTC, or "longitudinal time code." You record LTC on a separate portion of the videotape, most often on an unused linear audio track. To take advantage of this kind of time code, you will either need to purchase an editing recorder with a built-in time-code generator or buy an external time-code generator. You can connect an external time-code generator to VCRs that give you direct access to the linear audio track (Panasonics AG-1980, for example).

For those who care enough to spend the extra money, most industrial (not consumer) editing recorders offer you the opportunity to work with either VITC or LTC. Usually you select your time code option with the flip of a switch. If you decide to work with LTC, your recorder will typically give you the option of recording either audio or LTC to channel 2. Again, selecting LTC over audio is often as easy as flipping a switch. To avoid recording over existing video and audio signals, however, you have to do an insert edit and record time code only on audio channel 2. To do this, you must use editing decks with the audio dub feature.

For those working with consumer Hi8 camcorders, theres RCTC (Rewritable Consumer Time Code), a type of time code thats written onto its own reserved portion of the Hi8 tape. RCTC has the advantage of being re-writable, as its name suggests, but has one significant flaw: it isnt precisely frame-accurate. Industry specifications list its accuracy at plus or minus 2-5 frames, but many video editors have found it to be more accurate than this in practice--something closer to 1-2 frames in most cases. If you want dead-on frame accuracy with Hi8 tape, youll need to work with professional equipment that supports a type of code called (appropriately enough) 8mm time code.

Finally, most DV camcorders generate a type of time code called DV time code. Like RCTC, DV time code is recorded onto a special reserved section of the tape.

The reason you need to know about all the different types of time code is that all of your equipment has to be able to work together. Make sure that your decks use the same editing protocol and time code as your edit controller, or that you can connect an external time-code generator to your existing equipment.

Is Time Code for Me?
So now that you understand what time code is, you may be wondering if its all that important to your video production.

The answer lies in the kind of video you want to create. If youre like many of us and just whip out your camcorder every time your child or grandchild says "Goo!", then you probably dont need to make the additional investment in time code equipment. You might, however, be documenting your new granddaughters growth to make a special sweet-sixteen present for her, when the time comes. Perhaps youve taken up shooting insurance videos for the neighbors as a side occupation. In either of these--or many other--cases where you can expect to spend considerable time editing, time code can offer you enormous advantages.

For example, youve just shot some footage of the local high school band marching in a parade. Youve gotten a great shot of your best friends son banging away on the bass drum. In your mind, youve pictured the introduction to a video you want to create for your friend as a Christmas present. The intro ends on a specific drum beat, and then cuts to black. Without the use of time code, you would have to trust your eye or the speed of your index finger to come out of the edit right on that drum beat. With time code, however, you could program your edit controller to end the edit on that specific frame.

Other Benefits of Time Code
Time code offers other advantages to video editors. For example, as you shoot more video, you may find it difficult to mentally keep track of all your footage. Thats when it makes sense to log all your reels. Time code makes logging tapes a relatively simple exercise. Because you number all of your frames, it is easy to describe sequences of video in terms of their starting points, ending points, or both. So when the time comes to find those particular shots you want to use in your program, you can turn to your log sheets and not only know which reels to use, but exactly where on those reels you can find the footage you need. This can save a lot of time in the edit suite.

Additionally, you may reach a point where you need to incorporate other media into your productions. If you hire a professional narrator to record a voice-over in a professional recording suite, you may want to sync it up accurately to your edited master videotape. To do so, youll most likely have to record the audio to a DAT, or "digital audio tape." Many kinds of DAT tapes allow you to record time code on them. As such, you can record time code first to your master videotape and then transfer it to the DAT tape. Then in the final edit, you can sync your narration to your edited video quickly and easily.

Finally, in this ever-changing world of desktop and digital video, you may find that certain nonlinear editing systems require that you use time code on your tapes. This is because in nonlinear editing, you have to capture video initially at low resolution for rough editing and then recapture it at high resolution after editing is complete. The only way for the software to keep track of what footage is being used and precisely what to recapture is through the use of time code. Many packages create databases that hold time code data in them for use during the recapture process.

Be Not Afraid
So if youre ready to make the leap into time code editing, and if youre willing to make the investment in the equipment that will give you access to time code, you need not be afraid or apprehensive. Time code is the next step toward making truly professional-looking video. It facilitates the editing process and makes your life as a video editor easier. In the end, time code is one aspect of video that you can probably expect to remain the same throughout all the changes happening in the dynamic world of video production.

Art Aiello is a marketing communications specialist and former professional video producer.

Tags:  November 1997
Sat, 11/01/1997 - 12:00am