What does a TBC do?

[barney]

I see that many people that use Video Toasters also have a couple TBC installed in their system.  What exactly does this thing do?  Is it worth owning and is it difficult to use? Just curious.

[amiman99]

TBCs correct and synchronize the video source to each other.
Video Toaster NEEDs them to operate correctly.
Very easy to use, just video IN, video OUT, sync.
Video Toaster manual shows you how to connect them correctly.

BTW, you can use the TBC to strip the Macro-vision from DVDs and VHS.

[psxphill]

I see that many people that use Video Toasters also have a couple TBC installed in their system. What exactly does this thing do? Is it worth owning and is it difficult to use? Just curious.

It is basically a frame grabber that starts outputting the frame when triggered by a sync from another video source. It allows you to switch between the two signals.

[Ral-Clan]

It is basically a frame grabber that starts outputting the frame when triggered by a sync from another video source. It allows you to switch between the two signals.

Also needed when doing fades and glenlocking (i.e. combining two sources in sync).  If not used then the picture can begin to roll and tear and other nasty stuff.

All this applies to analogue video signals only, as far as I know.

[amiman99]

When you have a Video Toaster and you want to do any wipes from one source to another then you NEED at least one if the first input is from video camera, if your inputs are from VCRs then you need 2 TBCs.
VHS signal is not stable at all, you need to fix it before using in the Video Toaster.

[barney]

Pretty cool.  Thanks for the info.

[Matt_H]

You don't need one under all circumstances. Their main function back in the day was to correct the unstable analog video signal output by VCRs. Live cameras and digital video sources (DVD players, DV cameras) don't need them, for instance.

Although I think if you have more than one input source, regardless of whether it's digital or not, you do need one (or two?). That was never really clear to me, since the manuals all pre-date the digital formats.

[amiman99]

You don't need one under all circumstances. Their main function back in the day was to correct the unstable analog video signal output by VCRs. Live cameras and digital video sources (DVD players, DV cameras) don't need them, for instance.

Although I think if you have more than one input source, regardless of whether it's digital or not, you do need one (or two?). That was never really clear to me, since the manuals all pre-date the digital formats.

If your source is camera with stable input you dont need one, in this situation you could use Toaster as a genlock.
When you have 2 sources and one of them is stable you can use one TBC, just connect stable input to Genlock IN and other to Video IN.

[Tripitaka]

To be honest the Wiki entry for TBC's is very good:

http://en.wikipedia.org/wiki/Time_base_correction

If your after a master sync I highly recommend this one (having used one in a professional studio for several years):

http://www.amiga-hardware.com/showhardware.cgi?HARDID=1298

Of course, many studio quality video units have built in TBC's but they are often completely rubbish or at least a bit iffy.

IMHO most video errors are caused by one of three things, improper sync, improper termination of the video signal (easily spotted as your video signal will be over bright), or a lack of understanding of the video standards themselves (particularly aspect ratios and drop frames).

[Ami_GFX]

The Kitchen Sync is a really good TBC for the Video Toaster as are all the Leitech DPS ones. The Toaster is really fussy about the video it can sync to. The TBC was necessary with VCRs because of tape instability. Older analog NTSC cameras, laser disc and DVD players are fine without one. Newer video equipment uses newer digital HD video standards that are converted to analog and scaled to ntsc composite at the composite output and I've had to use a TBC with just about everything that has a HDMI or DVI output due to the varying quality of the analog video out from them.

TBCs actually convert the analog to digital internally order to process it and it is converted to analog again at the output and they can do all kinds of processing of the video signal in addition to stablilizing and syncronizing it. The most useful one is they can freeze video much better than the toaster which makes taking framestores a lot easier. A lot of them use 4:2:2 video compression internally which is still used today in satellite broadcasting to conserve bandwidth. They are very advanced devices for the times they were made in.

I use a Kitchen Sync with my Toaster 4000. A few years ago, I had a Toaster 2000 with a DPS TBC III. Both have their strong points. It took me a while to get both channels working again on my Kitchen Sync but now that it is fully working, I love it.