Help me understand SMPTE

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If I send a SMPTE signal from my MOTU 828MKII to a video camera, what
exactly does that do? For the camera? For me? For anything? Thanks.

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<bayareamusician@hotmail.com> wrote:
> If I send a SMPTE signal from my MOTU 828MKII
> to a video camera, what exactly does that do? For the
> camera? For me? For anything? Thanks.

If you ask for SMPTE you get:
http://searchdatacenter.techtarget [...] 22,00.html

Therefore better ask:
http://www.google.com/search?&q=sm [...] e+glossary

A frame-numbering system developed by SMPTE that assigns
a number to each frame of video. The 8-digit code is in the form
HH:MM:SS:FF (hours, minutes, seconds, frame number).
The numbers track elapsed hours, minutes, seconds, and
frames from any chosen point.

SMPTE is time code recorded on an audio channel of a tape
and is used to label each block or frame of a tape with a
unique identifying address. Commonly used when referring
to either DAT or U-Matic tape.

Cheers Jens

Archived from groups: rec.audio.pro (More info?)

In article <11ehr8scihden3b@corp.supernews.com>,
Richard Crowley <rcrowley@xpr7t.net> wrote:
>"Scott Dorsey" wrote ...
>> bayareamusician wrote:
>>> If I send a SMPTE signal from my MOTU 828MKII to a
>>> video camera, what exactly does that do? For the camera?
>>> For me? For anything? Thanks.
>>
>> It means you get a videotape with SMPTE timecode on it.
>> So when you take the tape or files you recorded on the MOTU
>> system and the videotape to the post house, they can synch
>> the two together.
>>
>> SMPTE is a timecode signal... it just repeats the current time
>> every frame.
>
>Note that feeding TC to a camera doesn't necessarily cause the
>camera to *sync* to the TC. It could still be "wild" compared
>to the video genlock standard.

Right! In the film world, it doesn't sycnh at all, it just records
timecode on each frame, and leaves it up to the post guys to do the
actual synchronization. Video is probably the same.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

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Scott Dorsey wrote:

> In article <11ehr8scihden3b@corp.supernews.com>,
> Richard Crowley <rcrowley@xpr7t.net> wrote:
> >"Scott Dorsey" wrote ...
> >> bayareamusician wrote:
> >>> If I send a SMPTE signal from my MOTU 828MKII to a
> >>> video camera, what exactly does that do? For the camera?
> >>> For me? For anything? Thanks.
> >>
> >> It means you get a videotape with SMPTE timecode on it.
> >> So when you take the tape or files you recorded on the MOTU
> >> system and the videotape to the post house, they can synch
> >> the two together.
> >>
> >> SMPTE is a timecode signal... it just repeats the current time
> >> every frame.
> >
> >Note that feeding TC to a camera doesn't necessarily cause the
> >camera to *sync* to the TC. It could still be "wild" compared
> >to the video genlock standard.
>
> Right! In the film world, it doesn't sycnh at all, it just records
> timecode on each frame, and leaves it up to the post guys to do the
> actual synchronization. Video is probably the same.

Nah. Video will sync up to SMPTE no problem unless the camera came out
of the ark. I expect most film cameras of recent manufacture will too.

There's little point otherwise. The frame rate is very important.

Graham

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On 28/07/05 19:27, in article 42E9156D.66BF3038@hotmail.com, "Pooh Bear"
<rabbitsfriendsandrelations@hotmail.com> wrote:

(...)
>> Right! In the film world, it doesn't sycnh at all, it just records
>> timecode on each frame, and leaves it up to the post guys to do the
>> actual synchronization. Video is probably the same.
>
> Nah. Video will sync up to SMPTE no problem unless the camera came out
> of the ark. I expect most film cameras of recent manufacture will too.
>
> There's little point otherwise. The frame rate is very important.

Nah. On most productions, you sync to the slate, basta. In the cutting room.
You you wanna do it fancy, get a smart slate, which displays the sound tc on
the slate.

You can do TC with most cameras, and auto-sync in post, but nobody really
uses it. You have to be anal about jamming TC, and most ACs can't be
bothered. And many post houses don't even have the equipment to read the
on-film TC...
On the last one I did, we tried it, we convinced to post house to invest
into the Aaton Keylink, and than we had to teach them how to use it...

And, yes, the frame rate is important, but I suspect not in the way you
think... Most stuff we do, camera is 24FPS, and sound is 25FPS...

Film is an oldfashioned business... When the first HD recorders appeared on
sets (not so very long ago), we had to convince many post houses to adapt to
that too... "What is, Nagra or DAT? - It's a DVD-Ram - Huh?"


--
Joe Kotroczo kotroczo@mac.com

Archived from groups: rec.audio.pro (More info?)

Richard Crowley wrote:

> "Pooh Bear" wrote ...
> > Nah. Video will sync up to SMPTE no problem unless the camera
> > came out of the ark. I expect most film cameras of recent manufacture
> > will too.
>
> No, I don't think so. I have the service manual for my DSR-300
> (pro DVCAM) and the TC signal path and the GL signal path
> don't even know about each other.
>
> Besides there is MUCH more to genlock than frame pacing
> (horizontal phase and subcarrier phase, to be precise).

Actually I was thinking more of betacam. There's no significant technical
reason why other formats shouldn't be *able* to lock to SMPTE though. I
guess it's marketing.

Graham

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On 28/07/05 20:37, in article 42E92600.2C03D6FC@hotmail.com, "Pooh Bear"
<rabbitsfriendsandrelations@hotmail.com> wrote:


>>> Nah. Video will sync up to SMPTE no problem unless the camera
>>> came out of the ark. I expect most film cameras of recent manufacture
>>> will too.
>>
>> No, I don't think so. I have the service manual for my DSR-300
>> (pro DVCAM) and the TC signal path and the GL signal path
>> don't even know about each other.
>>
>> Besides there is MUCH more to genlock than frame pacing
>> (horizontal phase and subcarrier phase, to be precise).
>
> Sure thing about subcarrier etc. But when it gets digitised and fed into a
> non-linear editing suite it becomes irrelevant.

If it's a DVCam, it gets digitized inside the camera, doesn't it?


--
Joe Kotroczo kotroczo@mac.com

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Scott Dorsey wrote:

> Joe Kotroczo <kotroczo@mac.com> wrote:
> >
> >You can do TC with most cameras, and auto-sync in post, but nobody really
> >uses it. You have to be anal about jamming TC, and most ACs can't be
> >bothered. And many post houses don't even have the equipment to read the
> >on-film TC...
> >On the last one I did, we tried it, we convinced to post house to invest
> >into the Aaton Keylink, and than we had to teach them how to use it...
>
> This is really just a wonderful thing for documentary work, where you
> are starting and stopping the camera a lot and don't have time to slate
> everything, though.

Yes, let's face it, the clapper board is hardly *hi-tech* ! - even if it does
have an LED display ! ;-)

Graham

Archived from groups: rec.audio.pro (More info?)

"Joe Kotroczo" wrote ...
> If it's a DVCam, it gets digitized inside the camera, doesn't it?

Yes, but the issue is whether the camera actually locks to the
"frame-rate" of the SMPTE timecode, or whether it just takes
the nearest TC value that came in and assigns it to the next
block of frame data written to the tape.

I very much believe it is the latter. Which is why cameras of that
genre have *both* TC input and GL input.

Archived from groups: rec.audio.pro (More info?)

Joe Kotroczo wrote:

> On 28/07/05 20:33, in article dcb8d1$f07$1@panix2.panix.com, "Scott Dorsey"
> <kludge@panix.com> wrote:
>
> >> You can do TC with most cameras, and auto-sync in post, but nobody really
> >> uses it. You have to be anal about jamming TC, and most ACs can't be
> >> bothered. And many post houses don't even have the equipment to read the
> >> on-film TC...
> >> On the last one I did, we tried it, we convinced to post house to invest
> >> into the Aaton Keylink, and than we had to teach them how to use it...
> >
> > This is really just a wonderful thing for documentary work, where you
> > are starting and stopping the camera a lot and don't have time to slate
> > everything, though.
>
> Yes, absolutely, especially if you do your own editing and have to do
> everything by yourself. Or if you do a multi-camera shoot of a concert...
>
> But on feature films, it doesn't really matter, things get slated properly,
> and that works fine. (And has worked fine for a very long time.) So why make
> your life (on set) complicated with timecode? Smart slates are a good idea
> though, if you can convice production to pay for them.
>
> We did it on that movie, by the way, because the DOP and the sound engineer
> both wanted to play with their Aaton toys... (35-3P and Cantar) And no, the
> 35-3P (3perf) is not "virtually noiseless", as they claim. Still louder than
> an Arri 535 in 4perf. IMHO.

Sorry, I don't understand what's *complicated* about timecode !

It's a very simple measure to ensure sync.

Graham

Archived from groups: rec.audio.pro (More info?)

On Thu, 28 Jul 2005 21:28:39 +0100, in rec.audio.pro Pooh Bear
<rabbitsfriendsandrelations@hotmail.com> wrote:

>Joe Kotroczo wrote:
>
>> On 28/07/05 20:33, in article dcb8d1$f07$1@panix2.panix.com, "Scott Dorsey"
>> <kludge@panix.com> wrote:
>>
>> >> You can do TC with most cameras, and auto-sync in post, but nobody really
>> >> uses it. You have to be anal about jamming TC, and most ACs can't be
>> >> bothered. And many post houses don't even have the equipment to read the
>> >> on-film TC...
>> >> On the last one I did, we tried it, we convinced to post house to invest
>> >> into the Aaton Keylink, and than we had to teach them how to use it...
>> >
>> > This is really just a wonderful thing for documentary work, where you
>> > are starting and stopping the camera a lot and don't have time to slate
>> > everything, though.
>>
>> Yes, absolutely, especially if you do your own editing and have to do
>> everything by yourself. Or if you do a multi-camera shoot of a concert...
>>
>> But on feature films, it doesn't really matter, things get slated properly,
>> and that works fine. (And has worked fine for a very long time.) So why make
>> your life (on set) complicated with timecode? Smart slates are a good idea
>> though, if you can convice production to pay for them.
>>
>> We did it on that movie, by the way, because the DOP and the sound engineer
>> both wanted to play with their Aaton toys... (35-3P and Cantar) And no, the
>> 35-3P (3perf) is not "virtually noiseless", as they claim. Still louder than
>> an Arri 535 in 4perf. IMHO.
>
>Sorry, I don't understand what's *complicated* about timecode !
>
>It's a very simple measure to ensure sync.
>
>Graham
ah not so simple
30Vs29.97fps, 3:2 pull down Pal/Ntsc frame rates, and with HD around
the corner things can get very confused in Post.

I was recently chatting to about this to a friend who is still in the
TeeVee industry (Poor Sod), cant remember if it was C4, Carlton or
Sky, but they have up to 7 different formats for some programs.

Dont ask.....


martin

Archived from groups: rec.audio.pro (More info?)

martin griffith wrote:

> On Thu, 28 Jul 2005 21:28:39 +0100, in rec.audio.pro Pooh Bear
> <rabbitsfriendsandrelations@hotmail.com> wrote:
>
> >Joe Kotroczo wrote:
> >
> >> On 28/07/05 20:33, in article dcb8d1$f07$1@panix2.panix.com, "Scott Dorsey"
> >> <kludge@panix.com> wrote:
> >>
> >> >> You can do TC with most cameras, and auto-sync in post, but nobody really
> >> >> uses it. You have to be anal about jamming TC, and most ACs can't be
> >> >> bothered. And many post houses don't even have the equipment to read the
> >> >> on-film TC...
> >> >> On the last one I did, we tried it, we convinced to post house to invest
> >> >> into the Aaton Keylink, and than we had to teach them how to use it...
> >> >
> >> > This is really just a wonderful thing for documentary work, where you
> >> > are starting and stopping the camera a lot and don't have time to slate
> >> > everything, though.
> >>
> >> Yes, absolutely, especially if you do your own editing and have to do
> >> everything by yourself. Or if you do a multi-camera shoot of a concert...
> >>
> >> But on feature films, it doesn't really matter, things get slated properly,
> >> and that works fine. (And has worked fine for a very long time.) So why make
> >> your life (on set) complicated with timecode? Smart slates are a good idea
> >> though, if you can convice production to pay for them.
> >>
> >> We did it on that movie, by the way, because the DOP and the sound engineer
> >> both wanted to play with their Aaton toys... (35-3P and Cantar) And no, the
> >> 35-3P (3perf) is not "virtually noiseless", as they claim. Still louder than
> >> an Arri 535 in 4perf. IMHO.
> >
> >Sorry, I don't understand what's *complicated* about timecode !
> >
> >It's a very simple measure to ensure sync.
> >
> >Graham
> ah not so simple
> 30Vs29.97fps, 3:2 pull down Pal/Ntsc frame rates, and with HD around
> the corner things can get very confused in Post.
>
> I was recently chatting to about this to a friend who is still in the
> TeeVee industry (Poor Sod), cant remember if it was C4, Carlton or
> Sky, but they have up to 7 different formats for some programs.
>
> Dont ask.....

Trust me - I won't !

Drop frame does my head in. I had a feeling you might mention this and I'm pleased
( after a fashion ) to say I recalled the number 29.97 too !

Aaarrrggghhh !

Graham

Archived from groups: rec.audio.pro (More info?)

Richard Crowley wrote:

> "Pooh Bear" wrote ...
> > Trust *you* to mention drop-frame ! I've never entirely
> > understood that one myself except that NTSC screwed up.
>
> Drop Frame refers only to dropping frame *numbers*.
> Since the NTSC frame rate is 0.01% fast (29.97 FPS)
> you must drop 0.01% of the frame *numbers* to keep
> the video numbering in sync with the wall-clock. You
> can read the spec to see exactly which frame numbers
> are always skipped, etc. Not as complicated as all that.
>
> NTSC was forced to "screw up" and change the frame
> rate from 30 FPS because of the requirement for down-
> ward compatibility with existing B&W (RS170) video
> standard and staying within the 6 MHz TV channel width.
> There were millions of TV receivers, and millions of $$$
> worth of origination equipment, etc. at stake.

Wasn't the 'screw-up' inherent in the 30fps 525 line standard though?

Graham

Archived from groups: rec.audio.pro (More info?)

"Pooh Bear" <rabbitsfriendsandrelations@hotmail.com> wrote in message
news:42E96E21.EA5BE7F8@hotmail.com...
> Richard Crowley wrote:
>
>> "Pooh Bear" wrote ...
>> > Trust *you* to mention drop-frame ! I've never entirely
>> > understood that one myself except that NTSC screwed up.
>>
>> Drop Frame refers only to dropping frame *numbers*.
>> Since the NTSC frame rate is 0.01% fast (29.97 FPS)
>> you must drop 0.01% of the frame *numbers* to keep
>> the video numbering in sync with the wall-clock. You
>> can read the spec to see exactly which frame numbers
>> are always skipped, etc. Not as complicated as all that.
>>
>> NTSC was forced to "screw up" and change the frame
>> rate from 30 FPS because of the requirement for down-
>> ward compatibility with existing B&W (RS170) video
>> standard and staying within the 6 MHz TV channel width.
>> There were millions of TV receivers, and millions of $$$
>> worth of origination equipment, etc. at stake.
>
> Wasn't the 'screw-up' inherent in the 30fps 525 line standard though?

No. Before color (NTSC), it was exactly 30.000 FPS.
Of course, there was no timecode back then, so nobody
appreciated it. :-)