VITC Layoff

[Baz Leffler]

Are you wanting to have the digibeta deck use the VITC in the SDI input as master timecode?

If you are using an A500 deck just switch the timecode switch under the panel to VITC and the above panel timecode switch to external and regen. This will force the decks timecode generator to lock to incoming VITC and record both as necessary.

Interestingly enough with Sony’s HDCAM series they allow for timecode in the data stream which is part of the SDI spec but Sony never catered for it with the A500 – A simple firmware update would have been nice Sony…..!!!

BAz

What would I do without the ‘UNDO’ button!!!!

[Michael Gissing]

Are you are going from the FCP timeline via SDI through the Teranex? If so then advance your sequence by four frames to compensate. VITC and LTC should match so let the deck generate both simultaneously and adjust your timeline.

If you are going tape to tape (say HDCam to Digi) then use machine control from the digi to the HDCam and do an assemble edit, again letting the digi generate code and advance the HDCam 4 frames to keep timing correct.

FCP doesn’t generate VITC so normally VITC is masked by your I/O card as it would be source timecode – not something you want on your digi master.

[Rafael Amador]

[Michael Gissing] “FCP doesn’t generate VITC so normally VITC is masked by your I/O card as it would be source timecode – not something you want on your digi master.”
Absolutely right.
QT files have no LTC, no VITC. They have QT TC.
The TC that travels in the SDI, I wouldn’t call it neither LTC.
In a QT file you may have different TCs for different purposes.
But who wants a tape where LTC and VITC do not match?

[Michael Gissing] If so then advance your sequence by four frames to compensate. VITC and LTC should match so let the deck generate both simultaneously and adjust your timeline. “
VTRs have only one TCG, so they can not generate different LTC and VITC at the same time.
VITC goes always embed in the picture, so the only way to get a VITC different than the LTC is by making a VIDEO INSERT
rafael.

http://www.nagavideo.com

[Gary Adcock]

[Rafael Amador] “QT files have no LTC, no VITC. They have QT TC. “

That is blatantly erroneous.

Quicktime is an application that supports many formats and flavors, QT of and by itself does not exclude VITC or LTC in a file. Some QT applications can read those signals, some cannot but to say that the application itself does not handle TC is erroneous.

There are something in the order of over 150 video only formats that can be read by the QT player. So you are telling everyone the the native DV codec, with it TC included in the file format does not exist?
Even though I can see and read even SMPTE TC embedded in the DV file that I can read in the QTplayer or in FCP? Of course you can.

What about RED or your Sony EX – you mean there is no SMTPE or TOD timecode there? not even in the camera native file formats as recorded in camera? QT makes up all those Numbers and throws them onscreen willy-nilly? What about all of the production tools that use some format that QT can read –

Technically most of TC info whether as LTC, ViTC, RP188 or VANC data only exists in the baseband video stream since most file formats do not see or understand what and where they need to go. This is the same on other platforms also.

Quicktime is nothing but a handler – if FCP cannot read nor write data from the file that is NOT a QT problem, it is an FCP problem not a QT problem.

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows

Inside look at the IoHD
https://library.creativecow.net/articles/adcock_gary/AJAIOHD.php

[Rafael Amador]

Hi Gary,
I accept that the video industry play with the names and terms as they want, but please don’t call this LTC and VITC.
When you export from FC you get a SMPTE TC embed in your file. This is not LTC neither VITC.
Is the TCG or the VTR who will make a LTC and VITC out of that TC.
LTC is an audio signal and goes in an audio like track. You must be able to listen it. VITC is a video signal and you must be able to watch it. Tell me where in FC are you able to do so.
rafael

http://www.nagavideo.com

[Gary Adcock]

[Rafael Amador] “I accept that the video industry play with the names and terms as they want, but please don’t call this LTC and VITC. “

I believe that your original statement was grossly inaccurate. First you said QT was at error, now your saying it is the industry for changing those names. Neither is true.

That FCP is lame in handling of TC is a totally separate issue.

[Rafael Amador] “When you export from FC you get a SMPTE TC embed in your file. This is not LTC neither VITC.”

Again you are incorrect. I quote
“Vertical Interval TimeCode (VITC, pronounced “vitsee”) is a form of SMPTE timecode embedded as a pair of black-and-white bars in a video signal. These lines are typically inserted into the vertical blanking interval of the video signal”https://en.wikipedia.org/wiki/Vertical_interval_timecode

SMPTE is the standard committee and all of these issues fall under either SMPTE or EBU specs for data timing- and both LTC and ViTC fall into this category.

“Is the TCG or the VTR who will make a LTC and VITC out of that TC. “
not true- the data is correct- the conversion will only place the TC stream in the proper location for the format (AND DEVICE) you are using –

If this is the case- where is TC stored / cached / held in your EX?
Under your example – NO Tapeless camera on the market today would have the ability to record a SMPTE/EBU TC stream – and we both know that is not true

[Rafael Amador] “LTC is an audio signal and goes in an audio like track. You must be able to listen it. VITC is a video signal and you must be able to watch it. Tell me where in FC are you able to do so. “

Never said FCP could, but I do have tools on my mac that do, I have hardware and software diagnostic tools that can and do read these signals. FCP is not the only tool I have at my disposal and I would

there are tools that can handle these in the real world- your tapeless workflow limits how much of this data is accessible- when you go to an completely uncompressed capture you will see many more thing that there – as long as you have the special tools that allow you to see and or hear these tracks.

Nearly everyday here on the COW some asks about “moving dots at the top of my picture frame” when capturing UC materials – that is the ViTC info in the overscan area ( Oh-you don’t see that in tapeless)
or that the LTC signal is audio – patch the TC out from a deck directly into a speaker- done it a number of times to match signals on multiple decks.

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows

Inside look at the IoHD
https://library.creativecow.net/articles/adcock_gary/AJAIOHD.php

[Rafael Amador]

Hi Gary,

[gary adcock] “If this is the case- where is TC stored / cached / held in your EX?
Under your example – NO Tapeless camera on the market today would have the ability to record a SMPTE/EBU TC stream – and we both know that is not true”

Don’t mix SMPTE with LTC and VITC. You my have a LTC and VITC in a standard different than the SMPTE and you my have the 80 bits per frame (2Kbps) of a SMPTE TC wherever you want, not necessarily in a longitudinal track neither in the Vertical interval. . My Ex-1 off course that have a SMPTE TC. But I don’t call it LTC.

This is a quotation of Wikipedia too:
“Linear (or Longitudinal) Timecode (LTC) encodes SMPTE timecode data as a Manchester-Biphase encoded audio signal”.

Manchester-Biphase encoding is coding system that makes sense in tapes because makes a clear difference f what a “0”and a “i” is. in a digital file makes no sense.

In my knowledge digital video have no Vertical Interval. hardly can have VITC.
MiniDV and DVCam they don’t lie the TC in any longitudinal track, but in the head of the Video tracks.
They use SMPTE TC and SONY can call that LTC, but i don’t call it like that. Could almost be call VITC because is wrote by the video-heads, but is not a part of the very image as it happens with the white dots from the Betacam.
You say that there are some applications that can read dose funny dots although that is not a VITC any more. Yes, a believe that. After years in front of the Betacam’s, I was able to read and interpret the dancing of the VITC by my self, and I’m not a TC reader:-)
Cheers,

http://www.nagavideo.com

[Gary Adcock]

[Rafael Amador] “Don’t mix SMPTE with LTC and VITC. You my have a LTC and VITC in a standard different than the SMPTE”

Actually thats impossible , there are no formats supported for TC that are not in the Society of Motion Picture Engineers / European Broadcast Union guidelines for professional broadcast standards.

SMTPE / EBU are the governing bodies for standardization of TC and TC information on this planet, they also determine where when and even sometimes how metadata of all types is used as part of the universal standards.

[Rafael Amador] “”Linear (or Longitudinal) Timecode (LTC) encodes SMPTE timecode data as a Manchester-Biphase encoded audio signal”….. some applications that can read dose funny dots although that is not a VITC any more “

Do you know what Manchester -Biphase encoding is? IT IS all those Dots on the screen– so the info could be read optically – now how do you read optically in a file?

That information still lives in a place on that file that is inserted into the baseband signal so that the time code information is in the proper time and location on the tape.

[Rafael Amador] “In my knowledge digital video have no Vertical Interval. hardly can have VITC. “

ALL broadcast signals have the all of this info stashed in the VANC space, the device reading determines whether it is LTC or VITC.

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows

Inside look at the IoHD
https://library.creativecow.net/articles/adcock_gary/AJAIOHD.php