Tim: >> In a TV studio, we'd call such a device a "proc amp" (video processing >> amplifier). Apart from allowing us to replace syncs, we can adjust >> various video signal levels at the same time. Claude Jones: > Interesting difference in common-usage. Here on the East Coast of the U.S. a > proc-amp is always used to refer to functions of some TBC's to do more than > stabilize (time base) a video signal - these are setup, video level, hue, > and chroma controls that allow you to process the signal as well as stabilize > it. Essentially that's the same thing, a proc amp, by itself, allows one to set video gain, set-up (pedestal), and phasing. Adjusting the analogue input to the time base corrector, so the inputed signal is normal. Some allow additional things (e.g. adjusting sync levels, generally by replacing the old sync with house sync). Since you're generally able to adjust video level independently of sync levels, it's common enough for the sync to be from an external source, rather than just using different gains and set-ups for the supplied video and its sync. > There are TBCs that only do the basic function - I have one. But that > function was to digitize an incoming video signal into a memory buffer, strip > out the sync, generate a new stable sync pulse, and then release the video > from the memory buffer in sync with that generated pulse. That may be just a resynchroniser. A real time base corrector also corrects time base errors (mechanical timing errors from tape playback). A resynchroniser just clocks out the output with house sync timing, and won't correct for minor jitters. They both have their uses, a resynchroniser is all that you'd need to feed a stable non-synchronous source (like a remote camera) into a video system, a time base corrector's needed to play back video tape without errors, and a fancy time base corrector has server interlinking with the VTR so it knows about servo errors and special play modes. > I have seen various video 'stabilizers' sold here in the U.S., usually > advertised in video magazines, and also sold on eBay, that were designed to > add stable sync to video "to improve picture viewing quality" - but, we all > knew what they were really for - eventually, you started seeing disclaimers > in the ads about not using them for illegal purposes. I have never used them > so I can't speak to whether they were any good. I built my own... ;-) The flickering TV set was driving me mental, with luminance flashes and vertical hold jitters. This was all with directly connected equipment, the sets just don't like the illegal video signals generated by Macrovision crap. It gets even worse if you have a projection set, as many of them don't blank out the vertical interval signals, so you'll see flashing Macrovision bars, VITC, VITS and other stuff flashing at the top of the frame. Grr, sodding morons! It doesn't do the slightest thing, at all, to prevent piracy. It just mucks things up for legit users. -- (This PC runs FC4, my others FC5 & FC6, in case that's important to the thread) Don't send private replies to my address, the mailbox is ignored. I read messages from the public lists.
