TIME CODE 1:15:21:071:15:21:081:15:21:091:15:21:101:15:21:11.

TIME CODE

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TIME CODE

• Time code is an additional electronic, digital signal which is recorded onto videotape as a reference for each video frame.

• It is for reference only.

1:15:21:07 1:15:21:08 1:15:21:09 1:15:21:10 1:15:21:11

TIME CODE

• Taking Your VCR's Pulse •

For every picture recorded on a videotape a pulse is recorded along the edge of the videotape. (30 every second)

• These control track pulses guide the videotape on Playback so that the video heads follow exactly the right path and speed to give you a clear picture.

Time code v.s Control Track

• The big problem with control track pulses is that they all look alike. (I'm sure they say the same thing about us humans.)

• The machine can count them backwards and forwards, but if it loses track by one or two pulses, it will never know.

Time Code

• If, on the other hand, each pulse had an identity of its own, like a serial number, then pulse #1153 would always be #1153.

• If a machine were told to place an edit at pulse #1153, it wouldn't accidentally make the edit #1152.

Time Code

• The machine would speed up, slow down, or do whatever was necessary to reach #1153 at the right moment, to execute its edit on schedule (or would abort the edit for you to try again).

• This is one of the big advantages of true time code. It allows for frame accurate editing.

Other Advantages to Time Code

• E.D.L (window burns)• No matter what

machine you place your tape in the time code remains the same

• If you were using control track, removing one tape and putting in another would confuse the machine. The VCR wouldn't know if you were picking up at the same number where it left off, or whether to start at zero, or what.

How Time code is recorded

• SMPTE time code is a digital signal whose ones and zeroes assign a number to every frame of video, representing hours, minutes, seconds, frames, and some additional user/specified information such as tape number.

TIME CODE

• 01:23:10:12

• 01:23:29:00HR MIN SEC FR

THERE ARE NO 00 FRAMES

------

01:23:10:29 01:23:11:01TO

Non Drop vs. Drop Frame

• Drop and non-drop timecodes are both methods of counting video frames. You would be correct to think of them like two languages. Just like "non" in French equals "no" in English. Each timecode counts and keeps tracks of video frames - they do not alter or drop video frames. They only count video frames and they count differently. In fact, drop frame timecode counts video frames accurately in relationship to real time. This is why all the networks and cable companies require that the final tape masters to be delivered are on drop-frame timecode.

Non-Drop Frame vs. Drop Frame

Clock time (electricity) operates at 60 Hz but the NTSC standard television operates at 59.94 Hz. Because of this speed difference between

59.94 Hz and 60Hz, there is an expanding elapsed time difference between the clock and

timecode readings.

Non-Drop frame

• Non-drop frame mode is used primarily by people making dvd’S , CD-I or other interactive programs where every frame needs to have a sequential identity so that the frame can be accurately located.

At the end of one hour of non-drop frame time code,

1 hour, 3 seconds, and 18 frames worth of actual time will have elapsed, a discrepancy of 108 frames. The problem is matching video time to clock time.

Drop frame

• The more popular method, drop frame mode, is used by most editors because it provides an accurate listing of elapsed time. It takes into account 60htz clock time and ntsc television 59.94 htz

• A better description would be “SKIP FRAME”

Drop Frame Time Code• The drop frame system is

a rather ingenious system

• No actual picture frames are dropped, only certain frame numbers

• Example

• 01:12:59:29 to 01:13:00:02.

• These occasional dropped frames add up to 108 at the end of an hour, making time code "time" and clock time match exactly.

1:12:59:29 1:13:00:02

Drop Frame Rules

• Two frames of time code are dropped from the start of each minute.

• The exception is every tenth minute.

• Using this method 108 frames of time code are dropped every minute.

• (54 minutes x 2 frames per minute = 108 frames)

• Non-drop timecode counts (labels) every single video frame and does not make any allowances for the fact that it is really 29.97 fps. Therefore, if you cut a scene using non-drop time code and the time reads as, say 30 minutes and 0 frames, this is not the actual running time of the scene. The actual time would be 30 minutes and 2 seconds.The total time must be converted in order to know the true running time. This is why non-drop lengths are always shorter than the real time. For example - it's counting 3000 frames for 100 seconds when it's really 2997 frames that equals 100 seconds. In other words, non-drop time code will count/label 3000 frames as 100 seconds, when it is actually 100 seconds and 3 frames. This is why the networks and cable companies require that their masters be delivered on drop frame time code.

The actual difference amounts to 108 frames per hour, or 86 seconds for each 24 hour period. This

equals 54 video frames per 30 minutes.

So if you are cutting a show using non-drop timecode, at the end of a 30 minute program, you

would need to add 1 second, 24 video frames to get the accurate time. It can be roughly calculated that a

program using non-drop timecode is two seconds shorter per half hour than the non-drop timecode

displayed.

Drop Frame ImportanceFriends has to be exactly 22 minutes and 28 seconds.

Drop frame = 22 minutes and 28 seconds CLOCK TIME

Non-drop frame = 22 minutes and 26 ½ seconds CLOCK TIME

Your are now a Time Code Expert

2005 ACADEMY AWARD NOMINATED EDITORS