Sync Flashcards

Uses an 80 bit word numbered 0-79 to carry the data for each address/frame and uses Manchester Bi-Phase Modulation to record square-wave binary data onto tape

How often LTC address is updated

25-30 times a second

Time Code

a standardized system/signal for giving accurate positional information to devices and is used to synchronize a device's position and movements with other devices.

How Striping works

uses fundamental frequencies (e.g. 1kHz and 2kHz between 24 and 30fps) to which human hearing is very sensitive and so cross talk between tape tracks (and console channels) is easily heard

How LTC should be recorded

at a low enough level to reduce cross talk but if it's too low, the noise floor will corrupt the data. Record at approximately -7VU

Where LTC should be recorded

on the highest numbered track and it is recommended to leave a blank track (if possible) between the Time Code track and any audio tracks.

Amount of striping that should be left before and after track

10 seconds

Advantages of SMTPE LTC

Can be striped/recorded onto tape before or after the audio/video data. Can be read at very high speeds. Can be used for both audio and video editing.

Disadvantages of SMPTE LTC

Cannot be read at very slow tape speeds or during tape pause. Uses up an audio track of it's own.

Shortcut to Arm Pro Tools to receive Sync

Apple J

Shortcut for Pro Tools Session Setup

Apple 2

used only on Video recordings as it is recorded as part of a Video frame in the vertical blinking section of the picture frame/field. It is recorded twice (to avoid any drop-out or other problems) onto any of the unused lines within the vertical blinking interval.

Advantages of VITC

Can be read at very slow tape speeds or even in picture pause mode (because the video head is always spinning). Video circuitry can record and read the data easily. Doesn't use up an audio track.

Disadvantages of VITC

Must be recorded at the same time as the video single - cannot be added later. Cannot be read at very high tape speeds.

Type of word VITC uses

90bit

Generator Reference

Can be sourced externally or internally to "conform" (control/correct) the generator's speed.

Time Code Degradation

Errors in time code when it is copied or when the tape becomes worn out

Reshaping

the wave is "sliced" (analyzed) to see when the waveform passes through the zero line. This produces a basic wave that is amplified and clipped to produce another healthy square wave level.

Reclocking/Regineration

The faulty TC is fed into a reader/generator. When the TC stream breaks up the generator produces a "fresh" time code signal. This is also called "Jam-sync".

Types of Regeneration/Jam-Sync

Auto and Momentary

Auto Jam-Sync

generated when the original time code becomes unreadable, it will automatically check the input signal to update its address values.

Momentary Jam-Sync

will start regenerating when first unreadable section is reached and will continue to regenerate regardless of the incoming time code.

Synchronization modes

Chase Lock, Phase Lock (Freewheel), Flywheel, Parking Mode

Chase Lock

Most common. The slave will automatically move to the TC location of the master (whether the master is moving or not). The slave will always chase to the time code position of the master.

Phase Lock (Freewheel)

Does not take time code addresses into account but only reads the sync word of each frame. This provides accurate phase lock (relative timing) between devices but there is no indication of actual positional info. (Speed-related and not position-related).

Sync Flashcards ionicons-v5-c