The Production Process: Postproduction
As the final stage of the video production process, postproduction affords the last opportunity to reach the goal originally set by the client. Regardless of the saying, “Fix it in post,” not all errors in judgment, mis-calculations, and poor production techniques can be corrected in post-production. If the material is not available or is technically deficient, there may be no way to replace it or to rectify the problems created in preproduction and/or production.
Most editors believe the truly creative portion of video production takes place in the editing room, and many directors and producers agree. Video editing is a function that requires a combination of technical and aesthetic knowledge and unlimited patience.
The technical factors depend on the capabilities of the equipment available for the editing session. A good editor knows the limits of the equipment and can use those limits without creating technical problems. The aesthetic factors call on knowledge of psychology, art, music, theater, and all performing arts. Editing is often a long, tedious process that stretches even the most patient people to their limit.
Linear Editing Systems
The equipment used to edit videotape ranges from two videotape decks connected for dubbing to the most complex, computer-controlled, all-digital, nonlinear systems. Linear editors use control track (CT) and/or time code (TC) editing as a means of controlling the tape decks and determining the location of the edits.
In linear editing suites, there are at least three pieces of equipment: a controller, a source deck, and a record deck. More complex suites may use more than one source deck with time base correctors (TBCs), a video switcher, character and graphic generators, and an audio control board with a complement of audio sources.
Audio Sources
An audio control board is not an absolute requirement for a simple linear editing suite, but some means of setting audio levels should be included in the system. A more satisfactory system includes an audio board that feeds the outputs of both the audio tracks from each of the source decks plus audio tape decks, turntable, compact disc (CD) player, and microphone outputs through the board. This setup allows you to mix more than one audio source and controls the levels and the equalization of the audio, if the board has this design feature.
CUTS-ONLY LINEAR EDITING
Controller
The controller is a specialized computer designed to perform three functions: controlling the playback functions of the source deck, controlling the play and record functions of the record deck, and storing this information. Controllers have a time readout that indicates the position of each tape in each deck. This time indicator on a CT system merely counts the CT pulses as they pass by a pickup head. In a TC system, the indicator reads the exact position of the tape, because the TC address is recorded directly onto the tape.
A controller uses either a knob or joystick as a method of shuttling the tapes back and forth. A single control can be assigned to an individual machine as needed, or there may be shuttle controls for each machine in the system. The standard Play, Record, Fast Forward, Rewind, and Stop buttons for each machine also appear on the controller. In addition, controls specifically designed for editing functions include a method of choosing between assemble or insert editing; switches to choose recording of either or both audio tracks and/or the video track in the insert editing mode; a method of indicating the entry and exit edit points on the source machine(s) and recorder; and, depending on the editor, switches that allow for previewing an edit without recording it, double-checking the entry and exit points, and reviewing the edit after it has been recorded.
Video Sources
The source deck (also called the player) and the recorder deck (sometimes known as the editor) are special videotape decks with additional circuits that allow the machines to be locked together in synchronization (sync). The controls on the decks are the same as on any tape deck, but there are ports for connecting cables to the controller that are not present on a standard tape deck. If the controller can handle more than one source deck, then a TBC for each source deck must be used to lock the recorders in sync so that a switcher can be used to record transitions other than cuts. Without TBCs and a switcher, cuts are the only transition possible.
If character and/or graphic generators and a camera are included as additional sources, they may be used through a switcher as long as they are gen-locked to the system. Gen-locking is the process of tying all of the synchronous signals of the tape decks to the same time reference so that shots can be freely combined through a switcher without causing the picture to lose sync and roll uncontrollably.
Linear Editing Methods: Technical
Two types of technical edits can be made using linear editing equipment: an assemble edit and an insert edit.
Assemble Edit
An assemble edit records the video track, both audio tracks, and the CT simultaneously. This offers a quick and simple method of editing one shot after another, but it prevents you from editing the video separately from either of the audio tracks or any combination of the three.
Insert Edit
An insert edit allows you to freely edit any of the three tracks separately, together, or in any combination. To achieve an insert edit, a continuous series of the CT pulses must be recorded first. This process is called laying down CT, black burst, or color bars. To lay down a continuous series of CTs, a complete video signal (no audio signal is needed) must be recorded on the tape.
One method, black burst, involves recording a black level signal from a signal generator or a switcher, or the signal from a capped camera. Another method is to record a color bar signal from a generator, switcher, or camera generating a color bar output. The signal must be continuous if the editing is to be accomplished on a CT editor. If the editing is being done on a TC editor, a TC signal is recorded in the vertical interval portion of the video signal (VITC), on a special TC track, or on an unused audio track at the same time as the black burst or color bars.
The choice of whether to record black or color bars on the video track depends on the final use of the tape. For master tapes that probably will not be duplicated, such as news stories, black is usually laid down. If a slight error is made in an edit that leaves a one- or two-frame gap between edits, the black will not be readily visible when the original master is played. However, if several generations of dubs are to be made with a frame or two of black, it may show as a flash or picture roll. When color bars are used, any gap between shots is easily seen at the time the tape is edited or previewed before dubs are made. Most professional postproduction facilities use color bars when laying down TC or CT.
Once black or color bar signals have been laid down, a professional editor seldom finds any need to edit using anything other than the insert mode. If CT or sync pulses are accidentally erased or damaged, an assemble edit will be necessary to restore the continuity of both pulses, but the edit will have to continue beyond the length of the finished production or additional assemble edits will need to be made.
Linear Editing Operating Methods
Every studio, facility, and station has a standard operating procedure (SOP) that designates the exact format to be used in laying down black burst, color bars, tone, and slate and for labeling of reels, cassettes, and boxes. This section is a compilation of an SOP that demonstrates the purposes of each segment of the operation.
Shuttle a new tape in fast-forward beyond the length of the anticipated edited master. Then rewind the tape to the beginning and reset the timer or TC reader to determine the beginning of the tape. Except for recording bars or black burst, no usable programming material should be recorded at the very beginning of a reel or cassette. Next, run the tape for 30 to 60 seconds to ensure that the tape stock is beyond any dirt that might have been picked up or any damaged tape that sometimes exists at the start of a tape cassette or reel.
Lay down 30 to 60 seconds of 1,000 Hz tone with bars as video. If these two test signals are not set at the exact levels to be used in the recording, they will be useless. These test signals are used by the technician preparing to play the tape back to set the playback levels and adjust for tracking, skew, and other electronic adjustments. Following the tone and bars, record about 10 seconds of a slate that specifies the title, length, client, date of recording, and, if a dub, which generation. Next, record a countdown with descending numbers from 10 to 2, followed by a minimum of 2 seconds of clean black and silence before the beginning of the first audio and video of the first shot of the edited production.
At the end of the production, record at least 10 seconds of clean black and silence. These periods of clean black and silence furnish a guard band of neutral signals in the event that there are errors in switching during a playback; they also provide a logical space for dubbing.
EDIT DECISION LIST-MASTER TAPE SIGNALS
Regardless of the level or complexity of the equipment used, the editing process consists of four basic steps: previewing the raw footage, physically preparing the master reel or computer session, laying down shots, and recording and labeling the final production tape or computer disc.
If a nonlinear system is used, these same steps reduce the time required to load the original footage onto a computer’s memory. The edit decision list (EDL) provides a means to choose only the critical and necessary shots required to be digitized for the project.
Assuming that you, as the editor, were not present during the shooting of the material and that accurate logs were kept, your first action is to review all of the raw footage. Then follow the logs and the script to begin to assimilate the material and reach an understanding of how the director interpreted the script with the shots recorded. If accurate logs were not kept during shooting, you must carefully preview the tape or computer files (called bins, derived from film terminology) and create a set of logs. If you were on the set at the time of shooting, the previewing process can be completed rapidly because you are already familiar with the footage that was shot.
Efficient Editing
One method of decreasing the cost of editing and increasing the efficiency of the process is to create window dubs of the raw footage on a less expensive format with matching TC numbers. Video Home System (VHS) is popular for most projects; professional ½-inch format is desirable if the production was shot on a digital professional format. The window dub may be used to make a preliminary edited master away from an editing suite.
Once the EDL is complete, either handwritten or computerized, and the original raw footage is taken to a fully equipped editing suite, an edited master is created. If the EDL is computer generated, the list is entered into the online computer; the tapes are cued up on a series of playback machines; and the computer then proceeds to make all of the edits, including transitions, special effects, and split edits. If the EDL was made carefully, then the online master can be edited automatically in a short time, saving time and money.
1. CHECK LABELS ON RAW FOOTAGE FROM SHOOT CREATE LABELS IF NONE ATTACHED
2. RECORD TIME CODE ON VITC, EXTRA AUDIO TRACK, OR SPECIAL TC TRACK IF NOT CODED WHEN RECORDED
3. DUB RAW FOOTAGE AND TIME CODE TO WINDOW DUB STOCK
4. PREVIEW AND LOG (OR CHECK LOGS) OF ALL FOOTAGE
5. EDIT OFF-LINE VERSION NOTING ALL EDIT POINTS (REEL NUMBER, EDIT NUMBER, ENTRY, EXIT POINTS, TRANSITION, AUDIO EDITS, AND SPECIAL EFFECTS) ON COMPUTER DISC, TAPE, OR MANUAL EDIT DECISION LIST
6. SEND ORIGINAL TAPE, OFF-LINE MASTER, AND EDL TO ON-LINE FACILITY
7. FOOTAGE WILL BE CUED ON MULTIPLE PLAYBACK DECKS AND COMPUTER WILL CONTROL ALL EDITING INSTRUCTIONS AS INDICATED ON THE EDL
8. NONLINEAR: DIGITIZE REQUIRED FOOTAGE USING EDIT DECISION LIST
9. ASSEMBLE SEQUENCES AND COMPLETE PROJECT
This section discusses the difference between linear and nonlinear editing. Until recently, videotape could be edited only in a linear manner; that is, each shot was added to the preceding shot. Changes could be made in either audio or video in previously edited sequences only if the overall length was not shortened or lengthened. Unlike film, which is edited in a nonlinear manner, a shot could be cut out or added at any point simply by splicing in a new shot or by cutting out an unwanted shot and resplicing at the removed shot in the film. Video editing does not involve physically cutting and splicing; therefore, if a shot must be shortened or lengthened, all shots after the changed shot must be reedited.
Nonlinear editing involves the following six basic steps:
1. Logging footage
2. Digitizing footage
3. Capturing footage
4. Assembling footage
5. Rendering file(s)
6. Outputting files
Nonlinear editing also depends on three factors not included in linear editing:
1. All edits are virtual; that is, no footage is actually used in the edit, only in and out points recorded in the application’s memory. Actual assembling of the clips (shots) does not occur until the rendering stage.
2. Because of the possible massive amount of memory required to digitize, manipulate, and render video clips, compression levels are critical to the quality of the final output and the amount of memory available or required. Compression is the process of digitizing only the critical portions of the video signal. Several compression systems are currently in use; the most common system for video is called MPEG. Since MPEG compression was first introduced, several different systems have evolved, each with a designator number such as MPEG-1 and MPEG-2. MPEG compression avoids digitizing any duplication between video frames, thereby saving memory space.
3. All material to be edited—audio, video, and graphics—must be in a common digital format to be edited nonlinearly. The material may be “captured” by any of three methods: by feeding directly from a digital camera through a FireWire or Serial Digital Interface (SDI) to the computer editing application, by feeding analog signals to a capture card installed in the computer, or by feeding the signal from a digital deck or passing an analog signal through a digital deck.
DIGITIZING FROM SHOOTING TO OUTPUT
Nonlinear Editing: Operating Methods
The nonlinear editing process starts in the same manner as all professional editing situations: with the shooting process. Keeping accurate logs at the time of recording the original footage makes the editing process simpler and more professional. If the footage is not accurately logged, then a logging session is necessary. All footage must be viewed on either the original footage or on a window dub. A window dub is a lower quality copy of the original footage with a window showing the TC as a reference in the lower third of the frame. This saves wear and tear on the original footage and may be accomplished on a consumer deck. Each shot needs to be logged with the in and out points and a brief description or title. This list becomes an EDL or batch list. If all of the footage is logged accurately with TC lists, then the digitizing process may proceed. As the footage is captured, it is stored in a bin in the computer application. Applications vary in descriptive terms, but the process is essentially the same. Clips are described and viewed in the list view window by title, length, and in and out points, among other items.
Footage then is assembled along a timeline in the assemble window. Each video and sound clip, graphic, and transition is added to the timeline in order by dragging the clip from the bin and placing it on the timeline. Clips may be trimmed and expanded, and transitions may be added along the timeline. After all clips and other materials have been assembled on the timeline, it may be previewed in real time to determine whether the edit is satisfactory. Because this is a virtual edit, no clips have actually been modified or lost. If the edit is satisfactory, the project is rendered, converting the virtual edit to an actual edit. The rendering process may take a few minutes or several days, depending on the length and complexity of the project.
Once rendered, the signal may be output to disc, tape, film, hard drive, or storage medium or converted to an analog signal for viewing and distribution. There is no technical difference between editing standard definition (SD) and high definition (HD), 4:3 and 16:9; it is just a matter of matching software and hardware. The original clips remain in the bin and may be used again in the same project or another project, or they may be stored for future use.
NONLINEAR EDITING PROCESS
As in any creative, artistic field, there is an infinite number of methods for assembling a creative work. As a starting point, professionals consider three basic methods for assembling a videotape.
In the first method, a master wide shot that is laid down covers the entire sequence in one take. Then individual close-ups (CUs), cut-ins, cutaways, and cover shots, as well as medium shots and reversals at appropriate times in the tape, are added. Music and sound effects or voice-over narration then may be added to fit the edited video. With this method, the master shot determines the sequence length. For commercials and some news stories, a specific length must not be exceeded. An interview can be edited in this way, as can a demonstration or a musical sequence. The disadvantage is that you are tied to the master shot. If a CU does not match the same line or action in the master shot, the CU cannot be used because continuity will be lost.
The second method requires editing each shot in sequence. Cover shots are added to smooth transitions and avoid jump cuts. This method requires an editor with considerable skill and knowledge of the production and the available raw footage. Music and sound effects may be added during editing or after all of the video has been assembled.
In the third method, the audio is prerecorded by laying down the main audio track first. In a narration-based production, the narration is the main audio track. Shots are then recorded to match the narration. Music and sound effects may be added last. An alternative method, often used with music videos, is to lay down the music first, then record the shots of the musician lip-syncing. Additional dramatic or illustrative shots are added at appropriate times during the musical number. Additional sound (e.g., sound effects, music) may be mixed with the main audio track, or the second audio track can be used for the music and sound effects.
In reality, most editors use a combination of all three methods, depending on the needs of the production during that particular sequence. If the master tape is to be duplicated or released on CD or digital video disc (DVD), then you must write specific and precise instructions according to the recommendations of the duplicating company.
Your final duties as an editor include properly labeling all of the master and raw footage stock and computer discs. The discs, footage, and the boxes they are stored in must be labeled. All paper records—shooting and editing logs, director’s and producer’s instructions, and bookkeeping forms and records required by the accounting department—must be filled out and properly filed. Your work as an editor ends as it began, dealing with a pile of paperwork in order to perform your job more efficiently.
As it is now obvious from the reading of this text, there is as much paperwork in media production as there is in any other single activity. The actual shooting of the production constitutes a minimum amount of the total time, although usually a maximum of the total physical effort, that goes into the production.
The critical stages occur during the preproduction and editing processes. If a production is not clearly and carefully planned before shooting starts, no amount of creative or physical effort will save the production. By the same token, if the shooting is not specifically planned with the editing process in mind, no amount of effort in the editing suite will salvage the production. These cautions apply to digital productions as much as to analog productions. The amazing capabilities of digital equipment will not be utilized if those capabilities are not properly planned for during the preproduction stages.
Also obvious is that there are few differences in electronic field production between analog and digital formats. Lighting, optics, audio, writing, composition and shooting, and basic editing all share the same techniques. Digital production from camera to final edited format will become the preferred medium, but all signals start and end as an analog signal.
My best advice is to plan for the worst and shoot for the best.