DVL-Digest 875 - Postings: Index Cross-fade formula? DV Decks with XLR interface? DV Vs. 601(too much information)(Diving deeper . . . oh no!) FCP capture takes atleast 30 seconds to start capture video Cross-fade formula? - Adam Wilt While I do strongly recommend understanding the history of visual > grammar/language - also read "Sculpting in Time" by Tarkovsky. Another good intro -- short and to the point -- is "Grammar of the Edit", Roy Thompson, Focal Press, 1992. I ran across it on a bookshelf at work last week and read it in 20 minutes (like I said, short and to the point). It's decidedly British, and television-oriented, but it has some useful guidelines. > You're not going to be that interesting or successful for very long > following some else's rules. > > Cinema and film/video stuff in general is an infant art form. Stop > acting like a bunch of stuffed fuddy duddies and let it grow up. The > next 100 years will be really exciting if it's allowed to develop. There's nothing wrong with experimentation -- but understanding the existing grammar and language is necessary if one is to depart from convention in a guided and informed way. Otherwise, it's all scattershot Monte Carlo work: throwing edits at the wall and seeing which ones stick, with no idea of what one is doing, or why. That way lies degeneration of the car-commercial kind: "dude, I gotta cut this spot on the Flame, 'cuz Frank from BBDO cut HIS spot last week on a Flame, an' I gotta have white flash frames and sudden speedups like that Dodge commercial I just saw, an' you have a DVE, right? We forgot to shoot everything with Dutch angles, an' it's all gotta have Dutch angles..." You *can* develop your own style from scratch, without reference to the century of work that has come before, but you risk losing your audience in the meantime. If you're trying to communicate, to tell a story, it pays to learn what has worked in the past, and what storytelling conventions have developed over time. It's a great timesaver. I myself have invented a variety of radical, earthshattering camera moves and editing techniques -- only to find that Vertov, Eisenstein, Godard, Hitchcock, Brakhage, Jost, and Kubrick had already been there, and done that! Cheers, Adam Wilt DV Decks with XLR interface? - Adam Wilt Actually I think that's probably the only "true" answer in that the > DSR-50 does actually support DV SP record and so is a "true" DV > deck. All the other XLR equiped DVCAM and DVCpro decks support > DV playback only, not record. Might I also add that the DSR-PD150 camcorder has XLRs (input only), and records DV as well as DVCAM? Cheaper even than the DSR-50, and you get a camera section on the front end of it at no additional charge! Cheers, Adam Wilt DV Vs. 601(too much information)(Diving deeper . . . oh no!) - Adam Wilt Well, I didn't want to dive this deep (a book's worth), but I was > hinting at the 4X versions > (you mentioned) that Sony and Panasonic (?) have for transfering DV . That would be SDTI, Serial Data Transport Interface, SMPTE 305.2M-2000. The prior, proprietary Sony and Panny versions were called CSDI and QSDI (or was it the other way 'round?). SDTI uses the 270-megabit SDI (Serial Digital Interface, SMPTE 259M) connection to send compressed DV25 at 1x or 4x, and DV50 at 1x or 2x, formatted to "look" like a standard uncompressed 601 video frame, so that the signal can be switched and routed using existing SDI infrastructure. The latest variation on the theme is SDTI-CP ("Content Package", SMPTE 326M-2000) used to carry MPEG-2 compressed information over an SDI channel. > The other thing is once the SDI signal is compressed (say once captured > into the computer) and when the final product is sent back to the tape > machine via SDI, even though that signal is technically uncompressed, all > the macro blocks of pixels from compression are still there, along with > all the artifacts That's true, if you've compressed the signal on the computer (or in the VTR -- DV25 and DV50 decks can use SDI connections, too!). > So SDI is an "uncompressed" signal, but NOT pristine. SDI (or more properly, the 13.5 MHz, 4:2:2 sampled ITU-R BT.601 component digital video signal carried thereupon; SDI can *also* carry 14.3 MHz composite serial digital, which is quite a different beastie) *is* uncompressed, and it does not muck with or compress the signal any further (let's leave aside for now the issue of 2:1 chroma-space compression inherent in 4:2:2 video). It is as pristine coming out of the SDI pipeline as it was going in. > Maybe Adam Wilt could describe what the waveform of a DV (4:1:1@ 5:1 > 8bit) signal would look like when transcoded to "uncompressed" SDI. > I'm sure it's no where as complex as a "uncompressed" digital betacam > signal (4:2:2 @ 2:1 10bit). DigiBeta is *not* uncompressed; it's DCT-coded (similar to DV) at around 1.7:1 or 2:1 or so. Again, whatever the source format, it can be uncompressed and sent as a 601-format signal over SDI. The SDI waveform itself looks like any other NRZI-coded digital signal: sort of undifferentiated-looking noise until you crank up the time scale on the 'scope to look at eye patterns. The decoded analog signal looks pretty much the same for uncompressed or DV-coded video: you'll see more edge distortions from mosquito noise and reduced chroma sampling on pathological test patterns like pulse, 2T, window, and similar test patterns. You may see artifacting on zone plates (though this'd be hard to see on the waveform monitor; it would show on the pix monitor. But in overall complexity, the waveforms are darned close -- whatever fiddly details the DV-sourced material loses in compression, it makes back in mosquito noise! Cheers, Adam Wilt FCP capture takes atleast 30 seconds to start capture video - Adam Wilt ...the software has to preallocate a file for the captured > video big enough to hold before the capture starts. The quickest way to shorten the delay is check the box that limits Capture Now to a fixed maximum, and set that maximum to the smallest number you feel comfortable with. I usually have it set to 20 minutes and Capture Now starts up in about a second and a half on a reasonably full and fragmented 36 GByte capture disk. Cheers, Adam Wilt (diese posts stammen von der DV-L Mailingliste - THX to Adam Wilt and Perry Mitchell :-) [up] |
 slashCAM  News HD Camcorder database One-on-One Cam comparison About our tests About us |
|
|
