[time-nuts] Time Code generator

[Magnus Danielson]

On 12/08/2010 07:18 PM, jimlux wrote:
> Chris Albertson wrote:
>> Adding time code to video would be redundant. All video is already
>> time coded.
> All *digital* video is timecoded..

No, not all digital video. The time-code is optional in many of the 
transfer formats.

> Record that video on an analog 1/2" or 3/4" deck and you need the
> timecode on the longitudinal audio track. Yes, primarily as you say, to
> support editing.
> It's been 12 years since I sat in an edit bay, so I'll bet that analog
> gear is pretty much out of the picture by now, though.

Analog black-bursts is still here.

>> But many consumer level cameras "fake" it by defining time = zero at
>> the start of a
>> tape or the first frame in memory. If absolute time needs to be record
>> on a
>> consumer level camera then I'd shoot a few frames of a digital clock
>> and then
>> later in a video editor adjust the time code
>
> That would work..(e.g. it's just like slating at the beginning of a film
> take) Sometimes it would be more convenient to just record an audio
> timecode on the audio track.
>
> Where I could see timecode being handy is when you're trying to do
> automated processing. I worked on a system 15 years ago where we had 100
> cameras, and we did the alignment by hand, and it was pretty painful.
> What's easy when syncing A and B roll gets tedious when there's 100
> takes you're essentially cutting together.

For Cameras it is not actual time which is important, but frame and line 
alignment needs to be aligned. Digital video mixers has line-stores on 
the input, so the cameras only needs to be synced to within a few lines 
such that the line-store can solve the rest.

If you fail syncing up you need to use a frame-store, which you try to 
avoid since it adds 40 ms of delay and you drop/duplicate frames. Even 
if you cut between the frames on the editing line, it is still a 
degradation you want to avoid, so syncing cameras is a good thing.

Taking the effort to sync up kind of make sense when you look on the 
alternatives.

Cheers,
Magnus