- Linear Editing
Linear editing is basically selecting a particular length of video and/or audio from one tape and copying it onto another tape. The operational principle here is copying, that is, the final programme is constructed in a linear fashion. The first shot is edited first, then the second, the third, and so on. In short, it is tape-to tape editing. Some prefer to refer to linear editing as analogue editing, owing to the transfer of footage from one tape to another.
We can perform a very basic edit by having one player and recorder. The process is very simple. Connect a player to a recorder. Insert a VHS tape of a film of your choice into the player. Insert an empty tape into the recorder. Now press the play button on the player and the record button on the recorder simultaneously. The film on the VHS tape will be transferred into the recorder tape. Now stop both machines and fast forward the player a bit. Start playing and press record on the recorder simultaneously. The second portion of the film on the player will be transferred to the recorder tape. This is, of course, a very simple edit.
However, professional linear editing machines are a bit more complex and require practice to handle them 
efficiently. A linear editing set up will require one or two players, an edit controller, a recorder, an SFX generator, an audio console to mix audio from the two video players, a vision mixer, and a minimum of two video monitors to observe the actual process of editing. A schematic diagram of a linear editing setup is given in the picture shows a typical A/B-roll linear editing setup.
An A/B-roll editing uses two players to play two shots simultaneously to edit will decide on the signal to be sent to the record deck. This technique also allows for chroma keying and picture-in-picture effects, among others.
A titling machine (not shown) is also connected to the controller to super titles onto the edited programme. One output from the edit controller is connected to a monitor that enables us to see and select from the shots we are playing back. Another output is connected to the recorder. The output from the recorder is connected to another monitor that enables us to see what we have edited so far.
Therefore, what we are essentially doing in linear editing is copying desired portions from raw footage onto an empty tape to create a programme. Remember, linear editing can result in what is known as generation loss. The quality of footage on the master tape (the tape on which the programme is edited) may be slightly lesser than the quality of raw footage. However, depending on the tape format, our programme can be of broadcast quality.
Linear editing is a complex process and requires some practice for smooth working. Linear editing works on what are known as two-point edits, three-point edits, or four-point edits. Linear editing requires a minimum of two 'in' points (one on the player and one on the recorder) to select a length of video/audio. When the desired length of video has been edited, the editor stops the edit controller. The edit controller helps the editor punch in the 'in' and 'out' points on the player or recorder. Marking three of the four points needed to place a source clip into a programme is called a three-point edit. For example, an editor identifies an in and out point in the source clip (on the player) and an in point in the programme (on the recorder) and allows the editing machine to calculate the out point in the programme. This technique allows for complex multi-track synchronised video/audio editing. Marking all the four in and out points on the player and recorder to place a source clip into a programme is called a four-point edit.
While it is pretty easy to do assemble edits on linear editing suites, insert editing, which is a common requirement of most video productions, will require practice.
Insert Editing on Linear System
First record a black signal on the entire source tape and rewind it to the beginning. It is important for a cameraperson or an editor to record at least 25 sec. of colour bars and 10 sec. of black. If the cameraperson happens to have recorded footage ri.ght from the first second on the tape, pre-roll (explained shortly) is not possible and therefore editing becomes difficult. The same applies for an editor for the tape in the recorder. On the recorder tape, first record 25 sec. of colour bars and 10 sec. black.
Next, select the shot from the player, using the edit controller, and mark the in point. You may want to select the desired length of the shot and mark
Roll it right
We had just graduated from linear to non-linear editing systems and were very excited about the creative opportunities this system offers. The camera person on the day's shoot inserted the cassette into the camera and started rolling. The first sfot was a beautiful sunrise with rays filtering between leaves. A great start indeed!
When the day's shoot ended, we were happy with the rushes. But when we sat down for editing and inserted the cassette into the player, the first shot would not get captured on the master! We tried all tricks at our command. Finally, the studio technician asked us to transfer the clip onto another tape that had colour bars and black recorded at the beginning. That helped us capture the shot.
Moral of the story whether you are working on a linear or an NLE system, pre-roll on the tape is very important.
An out too on the player. On the recorder too, select and mark the in point. Also select the video and both the audio channels on the edit controller for the recorder. Press the preview button. The preview button on the edit controller only tells you if you have chosen the right in and out points and does not actually edit the footage. If the in and out marks are okay in the preview, press the record button. The player rewinds and so does the recorder. The player and recorder rewind beyond the in point for up to 7 sec. and then accurately stop at the in point, but only for a moment. This is called pre-roll, the few seconds time taken by a VTR before it is put in the playback or record mode in order to give the electronic system time to stabilize. The recorder then begins to copy the selected portions on to its tape.
Video and both tracks of audio are now recorded onto the recorder tape (also called the master tape). Now repeat the process to edit the next shot and the next and the next until your editing is completed.
Having placed all the shots along with their audio, you can now insert some shots. Repeat the earlier procedure, this time choosing only video and deselecting both the audio tracks. Now your visual track is ready.
To replace one audio track with music, select Audio 2 on the edit controller and select the in point on the recorder. Now playback music from the source tape and press the edit button. One audio track is replaced by music.
You can also balance and mix the audio levels. Remove the tape from the recorder and place it in the player. Insert a new tape with blank signal recorded on it. Record 25 sec. of colour bars and
10 sec. of blank. Next mark the beginning of the tape in the source VTR as the in point and mark an in point on the recorder too. Select video and Audio 1 on the recorder tape using the edit controller. Using an audio mixer, balance and mix both the ambience sound and music for the film. Your film is now ready. If you want to add titles, you will have to redo the entire process, this time, keying in titles from another machine.
- Non-linear
Non-linear editing (NLE) is a slightly elaborate process but also the most sought after editing system these days owing to its flexibility.
NLE is like putting together a jig-saw puzzle-we arrange and rearrange pieces of scattered footage into a meaningful film. Editing video on a computer is basically NLE, that is, the film can be assembled in any order from beginning to end and changes can be made in the cut anywhere at any time. This is similar to working with word processing in Microsoft Word.
We key in a couple of paragraphs on a new document. After keying in, we realise that the fourth sentence sounds better in the first paragraph and the twentieth sentence sounds better in the fourth paragraph. All we do is select the sentences and 'cut' and 'paste' them at the desired place. Something similar happens in NLE. Little wonder it is called cut-copy-paste editing! But it is also not as simple as it sounds.
There are scores of inexpensive to very expensive and simple to very complex software available in the market for NLE,. However, they all follow some basic procedures, which are
- Digitizing, compressing, and storing
- Labelling stored information
- Juxtaposing, rearranging, and applying effects to audio and video files
- Copying edited programme back onto tape or burning onto a CD/ DVD
A nonlinear edit setup requires a fairly high-end computer that can handle audio, video, graphics, and a host of audio and video effects. A video recorder that also serves as a player is connected to the central processing unit (CPU) of the computer using a FireWire cable (Fig. 8.13). Depending on how high end the computer is, it could have one or two monitors to work on. The keyboard and mouse' enable us to control the software. The editing software also works as an interface between the recorder/player and the editor, that is, the recorder/player can be controlled by the keyboard and mouse.
The raw footage on tape is first digitised, that is, captured in digitised form onto the computer's hard disk (Fig. 8.14). Each shot needs to be named and arranged in different bins for easy editing. The software enables the editor to organise shots in different bins (Fig. 8.15) to facilitate easy editing. If our film has about three 'sections' -the opening, the middle, and the end-we can divide the footage required for the three sections and digitise footage onto the computer in three different bins. Further, we can import music into another bin and store all the graphics/titles we create in another bin. The bins must follow a nomenclature that will facilitate easy location.
Now we open a project window (Fig. 8.16) that shows the timeline. Now we are finally ready to do some editing. Because our footage is all digitised, we can access them any number of times. To do such a thing in linear editing, we would have to insert the tape that many number of times, rewind it, and then access the shot! Also, if we wanted to place a transition between two to three shots, we would require three VTRs in linear editing. In NLE, the process is simplified because all we would do is access a fil
e like we would on our desktop computer.
Therefore, on the time line we can arrange shots side by side at random and rearrange them to suit our needs. Our shots and audio are arranged in what are known as audio and video layers.
Depending on how high-end our software is, we can add a number of video and audio layers. Most systems also have a number of graphic layers. We can continue to add a number of graphics on those layers.
Know all!
A student of mine was asked to edit a short public service message (PSM). The NLE he was used to had developed a glitch. He was issued a newly installed NLE setup and he digitized the footage. His PSM required three layers of the same vid,2 clip to appear simultaneously in segments of three different colours. To be fair to the student, he did try hard for hours to get the effect, but in vain. He then walked up to me and declared the new NLE system inferior to the ones he was used to, and began berating it.
I accompanied him to the NLE to examine whether the problem could be fixed. All it required was laying the same video on three different layers on the timeline and applying the required colour effect along with desired transperancies. It worked! It produced the same effect that the earlier NLEs could!
Moral of the story Read the instruction manual carefully before working on an NLE. NLEs are different from each other and we need to adapt to them.
To apply effects, we go to the effects palette (Fig. 8.17), select an effect, and apply it on the timeline. If our computer and software are high-end, even complex effects are rendered real time. Otherwise, we may need to 'render' them. Rendering is the process of allowing the computer to implement all of the audio, video, and digital effects we have made, on a frame by-frame basis.
Remember that while effects are applied on a clip, transitions are applied between two clips. Some software allow us to apply multiple effects to a clip and multiple transitional effects between two clips. Most professional non-linear machines also allow us to customize the effects and transitions. Therefore, do not lose heart on seeing that there are only 110 effects.
They can be customized to create thousands of effects and transitions.
On the timeline, audio tracks are represented as integrated elements of the video clips. In other words, when we digitize a clip and import it to the timeline, we also import the audio along with the video. NLE machines allow you to work with multiple layers of audio to add sound effects, music, commentary, etc.
The software has the ability to adjust the volume of an audio clip anywhere on the timeline. It allows us a 'rubber band' (Fig. 8.18), using which we can do a number of things like :;;fade-in, fade-out, and cross-fade with audio on separate tracks.
We can import music and sound effects from CDs into separate bins and drag and drop them onto our timeline. Many NLE machines also allow us to equalise audio and add customizable effects like reverb and echo.
If we are satisfied with the entire editing, we can ask the computer to remember and record all the in and out points for each shot and all the effects we applied.
The computer will generate an edit decision list (EDL). An EDL is a standard way of representing a film or video edit 'on paper'. It contains an ordered list of tape and time code data, representing where each video clip can be obtained in order to conform to the final clj£" EDLs are available on most systems in printable formats. We can print them and keep them for future reference/use.
The advantage with an EDL is that we can use it on any other computer of the same operating system (MacOS or Windows) and software. All we need to do is capture the footage again in better resolution and the computer will lay out or replicate the 'edited version' of the programme on that computer. We can then rework on the programme if we wish to.
EDLs also work to our advantage if we are editing large amounts of material. We may want to consider using our system as an 'off-line' editing tool. Off-line is a term from traditional~\!ideo editing that refers to a lower quality edit used to make most or all of the editing decisions. The final version of the video is then re-edited on a high quality, 'on-line' system. The simplest way to accomplish this is to combine a NLE system with a professional video deck and deck control software. This combination allows us to incorporate the time code stamp of professional tape formats into the editing process. Time code is a way of representing time and position information about a tape in either an audio or visual form. Once we have worked out our decisions with low resolution material, the machine lets us directly recapture the material at a higher quality or to output an EDL. These techniques are of course dependent on how high-end our system is and its ability to reliably handle audio synchronisation and avoid dropped frames.
Having 'completed' the film, we can go ahead and 'print' it back on tape or burn it onto a CD or DVD. Every professional non-linear machine offers us a good DVD authoring option.
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