CompuServe Thread

Stu: >Tell me more, tell me more, about field/frame buffers. i remember when the AVE5 came out, Panasonic was mum but other proponents said it had built in TBCs. mu understanding is that they have a synchronizer that digitally stores a full frame and spits it out. would that be a frame buffer. what about field buffer? what does the Fast do? This is good stuff!! mucho grass!< Let me see if I can remember what I said about the AVE5 when I reviewed it (I can't, of course, *find* the text file on my review, since I filed it off nearly two years ago…). :-/ A digital field buffer does the same thing a digital frame buffer does, but less–it only stores video fields (half a frame) and synchronizes them between two video sources. This allows it to replicate some of the major TBC functions like synchronizing the signals between two different video sources, performing clean freeze frames (of the field stored in memory, which is why the freeze frames on an AVE5 are a bit "soft"), and also cleans up the signal slightly since it digitizes it. There is, however, little control over signal "tweaking" (esp. w/the AVE5, which has NO color/tint/ contrast controls whatsoever–I *think* the AVE7 has a few), and the signal quality's not as good as you'd get from a full-featured TBC, but it does well enough for most low-end industrial/special-occasion video, and it was a damned sight cheaper than TBCs used to be… That's what started the "phantom TBC" rumor–Panasonic Industrial (whose WJ-MX10s and -12s DIDN'T use digital frame/field buffers) didn't like the fact that a Panasonic Consumer unit was superior to theirs, and would squelch any rumors that a mere consumer unit had time base correction capability (esp. since their own units at the time *didn't*…). For Panasonic Consumer's part, it wasn't a true time base corrector, just an inexpensive alternative that was good enough for low-end use but wouldn't pass muster professionally, so they were afraid to admit to it. (I also suspect that the digital frame/field buffer technology might have under some confidentiality agreement at the time, though I sure can't confirm it!) After Peter Utz's review in CAMCORDER, however (actually, *he's* the one who started the "phantom TBC" rumor, IMO), folks started playing around w/the AVE-5 and discovered that, if you were willing to accept a less-than-broadcast quality video signal (if I recollect it properly, the AVE5's signal on a waveform monitor sorta looks like a plateau–real flat, and then drops off suddenly), you could use it as a cheaper version of the 2 TBCs that the Video Toaster required (the AVE7 can't be used that way, unfortunately), and that mixing two video sources was a LOT less problematic than it was w/the MX-10 or -12 (I used to get the *wateriest* dissolves from an MX-12 I was using at the time!). You'll need to confirm all this w/the parties involved for your article, of course, but that's what I remember happening. Hope this helps, Tim