DVL-Digest 640 - Postings: Index 100% color bars JVC HR-DVS1 Auto 16:9? Panasonic firewire WORKS! - (2) Realtime out analog [was:Proma tvnewsweb/ GY-DV700 Wide screen XL-1 vs VX-2000 100% color bars - Adam Wilt Thanks for the authoritative replies on 100% and 75% color bars. One last > question. How do you know which kind you have? The best way is to look at a waveform monitor and/or a vectorscope. The vectorscope is easiest; with the color bars all centered in their boxes, does the colorburst hit the 75% or the 100% calibration? Some 'scopes have a single calibration instead; with such devices, do the bars hit the boxes when the burst hits is mark when the 'scope is set up for 75% bars, or 100% bars? On a picture monitor, if you have SMPTE-style bars with the upper 2/3 of the screen showing bars, then a thin strip of complementary-color bars, then a section showing two bluish patches on either side of a white patch, the bars are probably 75% bars. To be sure, is the square white patch brighter than the left-hand white bar? If so, you have 75% bars; if they're the same, you have 100% bars (and they ain't really SMPTE bars). Most of the bars I've seen in NTSC-model DV camcorders are full-field, 75% color bars. If you have a DV NLE with 1394, and a codec that performs the "normal" YUV-RGB mapping (Adaptec DVSoft, Pinnacle DV200/300, QT 4.0.3 & 4.1.2, DV Plus in clamped luma/chroma, Matrox in "broadcast" range, Radius SoftDV in whichever range it is that clips whites, etc.), capture the bars and look at RGB values. Are they combinations of 0s and 191s or 192s? 75% bars. Are they mixtures of 0s and 254s or 255s? 100% bars. If the numbers you get aren't even close, then you either have a codec that performs a different YUV-RGB mapping, or your bars are out of whack. > Would it be possible to start with 75% color bars and mistakenly adjust > them to 100%? Yes, indeed. I always use SMPTE-style bars on master tapes, so the difference between the 100% white reference patch and the 75% white bar is an obvious tipoff, and I always send a cue sheet to the dub house that specifically mentions that the bars are 75%. With full-field bars or other nonstandard patterns, you really do need to use a 'scope to figure out what kind they are, and avoid colorful disaster. Cheers, Adam Wilt JVC HR-DVS1 Auto 16:9? - "Perry" Mike Jennings posted: >The component output are ColorStream component -- YCrCb, not Y, R-Y, B-Y. I don't know of a converter between these two component formats.< Hi Mike: I've no idea what ColorStream is, but Y,Cr,Cb are the proper names for the analog components of a Betacam signal. The commonly used Y,R-Y,B-Y are generic terms and don't represent the bandwidth restriction and scaling that is enforced on the Betacam colour components. The equally mis-used Y,U,V are strictly the components used in a composite video encoder, although you guys take it a stage further to Y,I,Q. Perry Mitchell Video Facilities http://www.perrybits.co.uk/ Panasonic firewire WORKS! - "Perry" At IBC Pana had a DVCPRO machine (not sure which) playing a DVCPRO tape through Firewire and into a Matrox 2000 board which apparently has the DVCPRO codec on board. The signal then got sent out as DV so we had the classic 4:1:1 to 4:2:2(or 4:4:4) to 4:2:0 scenario. Unfortunately the only monitor had such a coarse resolution that it was impossible to critically assess the quality which is difficult on random camera shots anyway. I sort of lost interest when the Matrox folk told me the DVCPRO codec won't be on the Mac version! Perry Mitchell Video Facilities http://www.perrybits.co.uk/ Panasonic firewire WORKS! - "Perry" Guy: It was recording TO DV so it had to come out 4:2:0! It was the transcoding (DVCPRO to DV) issue that is interesting as to the quality. Perry Mitchell Video Facilities http://www.perrybits.co.uk/ Realtime out analog [was:Proma - Adam Wilt Guy Bonneau corrects me: > > Today, the only realtime board that outputs DV directly is the Canopus > > DVRexRT, because it has an extra codec. > > No it doesn't. Like all DV product the DVRexRt has only > 1 hardware codec... My apologies, I was imprecise: the "other two" codecs that handle the decompression are Canopus' blazingly fast software codec, typically running on two CPUs (though some people report perfectly good dual-stream decode with only one CPU). The hardware codec on the Rex (the original codec, from way back when the Rex first came out) is now the "extra" codec that handles the recompression of the processed video. There are still two streams coming through the [software] codec[s] for decompression; effects and mixing are done in software; and the final stream is recompressed by the hardware codec. Regardless of hard vs. soft, it's that final recompression that many of the realtime boards out there can't do in realtime. At least, not yet... ;-) Cheers, Adam Wilt tvnewsweb/ GY-DV700 - "Perry" I also have a positive review of the GY-DV700 awaiting the next issue of CCE magazine. If any listers are desperate I'll happily send them a copy of the text. My closing paragraph is: >In conclusion, The GY-DV700 fulfils all that I’d hoped for in terms of image quality and has very few obvious failings. It will have to be seriously considered by all broadcasters chasing wide screen pictures with smaller budgets and will surely do well with all those that are willing to accept the DV format.< Perry Mitchell Video Facilities http://www.perrybits.co.uk/ Wide screen - "Perry" Elliot posted: >16:9 TV sets are now fairly common in UK. If they see the flag, they go widescreen.< On the subject: I notice the new BBC Breakfast News has gone 14:9! Normally this is the BBC compromise to show recorded widescreen material on 4:3 broadcasts. I cannot think of a single valid reason why a live show, going only to 4:3 broadcast, should have this setting. Any BBC listers want to comment? I suspect they have 16:9 sets in all their executive offices and sort of assume that everybody else in the country has the same! Mind you, the whole (new) show is a mess, although it improved this morning having sent the jester back to Jerusalem! Apologies to all the rest of the world! Perry Mitchell Video Facilities http://www.perrybits.co.uk/ XL-1 vs VX-2000 - "Perry" >I do not like the cold look of the 2000. The XL-1 has a warm, filmish picture....it is far more pleasing and less "videoy." If I want a picture like the Sony's h I just have to go to Radio Shack and buy a Tandy.< The Sony actually has a neutral colour balance as default, but it is very easy to offset the 'Custom Preset' to have any color bias you like. It is also easy to turn the 'Sharpness' right down if you like the soft look. Being cruel, if you really want to match the XL-1 you might need to defocus a little on the wide shots :} Perry Mitchell Video Facilities http://www.perrybits.co.uk/ (diese posts stammen von der DV-L Mailingliste - THX to Adam Wilt and Perry Mitchell :-) [up] |
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