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  1. Member
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    Mar 2020
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    Berlin
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    Hello,

    I have a question regarding VITC and analogue video, specifically VHS.
    In Television Technology Demystified by Aleksandar Todorrovic it seems to be suggested that the code, even when first used, was digital. This seems to make sense, I know digital technology was used in TV and Video long before 'digital video' but I've read online, here:

    https://www.tvtechnology.com/opinions/time-code-for-the-ages

    That 'Originally VITC was an analog waveform'

    (I don't think either of these are referring to VHS but VTIC more generally)

    So does anyone know which is correct? And if the code was originally analog, when did it switch to digital? The author seems to suggest that analogue video had analogue VTIC and digital had digital.

    Also, I was trying to find out more about the 32bits of User Data provided for in VITC. How would that be added? Was there any home user level equipment, the sort of edit controllers and mixers that were marketed at keen amateurs rather than professional, that could do this?

    Any help appreciated.
    Best wishes,
    G
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  2. It's digital data encoded as black and white (0 and 1) segments in the analog TV signal. Very similar to closed caption data:

    https://nootropicdesign.com/projectlab/2011/03/20/decoding-closed-captioning/

    When broadcast went digital such data was just included as a stream along with all the other digital data.
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  3. Member
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    Thanks!
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  4. Member Cornucopia's Avatar
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    Deep in the Heart of Texas
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    Whether LTC or VITC, most all the generators, readers & jam/sync'ers that were used were professional. Not really meant for even prosumers, because one usually already needed pro equipment with which to use them on.
    Most generators included a way to type in characters for the UserData bits. Those were often used for scene/tape/production marking, as they didn't change much throughout a sequence (unlike the timecode). I used to have a booklet that went into great detail about both LTC & VITC. Not sure if I can locate it rn, but if so, it could be informative to your liking.


    Scott
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  5. Member
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    Hi Scott,

    thank for your response and info. I can see why the User Data would not need to be altered frequently - but in theory could it have been? I wondered if someone had the time to key it it could the 32bits have been changed every frame? That booklet sounds interesting, if you ever locate it let me know. Thanks again.

    Best,

    G
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