DVL-Digest 683 - Postings: Index 1394 - 911 Beta w/TC - FCP Canon camcorder names Impedance converter What are the advantages of DirectX 8? 1394 - 911 - Adam Wilt If anyone on the list IS doing print-to-tape to DV over Firewire on a > VIA KT/KX-133 or other recent K7 chipset, I think that would offer an > interesting datapoint here. Dunno about the K7, but I've got a bunch of Asus CU4VX mobos with PIII/600 and PIII/800 CPUs. These use the Via Apollo Pro133A chipset, and seem to work fine capturing from and printing to tape, using the Radius 1394 card supplied with EditDV, the SIIG OHCI 1394 card using Vegas Video, and Canopus DVRaptor using Premiere 5.1c. All working under Windows 2000; the Canopus and Radius cards also worked fine under WinNT4 SP6. > What about trying a non-OHCI card? The Raptor is known for the quality of its drivers and its reluctance to misbehave. Canopus uses big memory buffers to avoid timing problems. The Canopus DV codec is better than Radius SoftDV, too, and runs rings around the DirectX codecs both in rendering quality and in speed. Cheers, Adam Wilt Beta w/TC - FCP - "Perry" Bill Strothman posted: >Question? doesn't the Beta deck have built in pads that you can switch for impedence match for both input and output?< Maybe time for some 'definitions': All pro broadcast decks, inc Betacams, have balanced audio input/output. This is intended for running long paths in studio conditions alongside noisy cables, and is much less likely to suffer crosstalk. The signal is carried on two antiphase wires that are 'balanced' about the third ground wire. The 'impedance' is an ideal load seen to the machine that ensures best signal/noise, and is usually 600ohms. There are many 'abuses' of correct termination and this is one of the prime reasons that tone levels are put on the front of all broadcasting shows. Consumer and Industrial decks use 'unbalanced' or 'single-ended' audio input/output with a single 'hot' signal wire and a ground. There is a large variation of nominal impedance load but 10kohm is typical, and it is simply the minimum load that does not seriously effect the output levels. Traditionally, balanced audio is produced using a centre tapped transformer. It is quite safe to connect this to an unbalanced input and the 10k load will give minimal signal reduction. The main problem is that typical broadcast audio levels are 18dB (= x8) higher than consumer/industrial 'Line' level, and even if you connect across only half the balanced signal then it will be much too high. The answer is an attenuator pad, and as Bill implies these are built into the Betacam circuit boards, but are rather inaccessible and are really only intended for matching the machine to different studio standards. It is very easy to include one in the converter lead to go from XLR (balanced) to Phono (unbalanced). Most Betacams have a separate 'Monitor' output which is often padded to a lower level. It is common now to produce balanced feeds from an all electronic driver, since good quality transformers are expensive. It is possible to damage such electronics with an unbalanced load so it is definitely safer to use a 'Balanced-Unbalanced' converter which is simply an external transformer. If these are to be used for program audio then they will not be cheap and will be about the size of a 35mm stills film container. I have some smaller ones I use for timecode audio and there is very serious loss of bass if used for music. FWIW Perry Mitchell Video Facilities http://www.perrybits.co.uk/ Canon camcorder names - "Perry" Having recently tested some one chip camcorders I'm interested in hearing views on these, but the Canon camcorders in Europe have different names. Anybody have an equivalents list? Perry Mitchell Video Facilities http://www.perrybits.co.uk/ Impedance converter - Adam Wilt If someone can tell me where to buy an Impedence converter on line??. If you're still looking, http://www.markertek.com has a few level and impedance matchers that convert between +4dB XLR and -10dB RCA audio. Cheers, Adam Wilt What are the advantages of DirectX 8? - Adam Wilt One advantage is that the DV codec is much improved. Instead of going green in one generation with 32-pixel-wide striping patterns visible by the 2nd generation, DX8 hold accurate color for up to five generations. Of course, after three generations you'll get a unique 8x8 pixel "screen door" or "rip-stop nylon" fixed pattern noise, but for one generation of rendering it's acceptable, and far, far better than DX7. (diese posts stammen von der DV-L Mailingliste - THX to Adam Wilt and Perry Mitchell :-) [up] |
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