Transcript ch14
Time-code Time-code An additional electronic, digital signal which is recorded onto videotape as a reference for each video frame. Time Code Word The entire time code signal Consists of 80 to 90 bits. Bits are voltage pulses created electronically by shifts or fluctuations in the voltage of the signal. Bit groups Time code address User bits Sync data drop frame/non-drop frame Time Code Address Gives each frame in the video signal a specific address. Hours: Minutes: Seconds: Frames 00:00:20:00 00:00:20:01 00:00:20:02 How Many Frames Later? where is time code recorded? Time code can be recorded as and audio signal, or as part of the video signal. Longitudinal Time Code LTC Time Code is recorded onto audio tracks. Two Types of Audio time code Address Track Time Code Production Audio Time code LTC It cannot be read or understood at very slow speeds It cannot be read when still Less accurate at 1/10 normal speed. Can be recorded after shoot. Production Audio track Code Audible signal. On one of audio tracks. Loose track for production audio. Audio 2 Time Code Address Track Time Code Audio signal Uses a third inaudible audio track, designated specifically for time code addresses. Control track Video Track Address Track-Time Code Audio Track 1 Audio Track 2 Vertical Interval Time Code Recorded onto video signal in area of picture unseen.( vertical blanking) VITC VITC Can be read at slow speeds Recorded at same time video signal is recorded. Inaccurate at fast speeds. Drop Frame and NonDrop Frame time code Black and white video is 30fps. this rate corresponds exactly to clock time Color video 29.97 fps. This creates a discrepancy between clock time and color video time. Drop Frame Time Code corrects the error of .03 frames per second. Every minute, two frames are dropped/ just the addresses. Every 10th minute two frames are not dropped. Drop Frame Time Code allows the difference between clock time and time code display. A program edited in non-drop frame would really be an hour and 3.6 seconds instead of one hour Edit Decision List EDL A list of edit point data. Off-line editing An off-line edit is any session where the finished product is an edit decision list. Different ways of off-line editing- written or computerized. On-Line Editing Is any edit where the finished product is an edited master. Effects only- you edit your entire program and only spend money on effects. Pre-edit-make a cut of show and use that as the tapes that are taken to on-line session Selective Pre-editing- only pre edit the shots that will be needed for transition Window Dub QuickTime™ and a Video decompressor are needed to see this picture. A copy of original material which has visible Time Code information keyed over the images Writing an EDl Make a note of every element that is included in a finished EDL Note Audio only and Video only edits separately-write down the numbers as soon as you make your edit. Split edits too. Make a note of every point you would like to have a transition other than a cut.- make sure you count the head and tail.