More commentary
Hi folks,
Glad to see some good, nuts-and-bolts technical discussion here on wdwmagic. I just got back from a trip to Disneyland helping with some technical upgrades of their Remember fireworks show, so I'll throw the following comments into the mix.
Addressing the ETC vs. High End issue regarding lighting consoles, it really all comes down to the extensive use of automated fixtures in a rig such as this. Many of ETC's consoles can chase to SMPTE (and do it rather well), and in fact an Obsession II is one of the lighting consoles used on DL's Fantasmic show. The problem is although some ETC consoles have built in controls for automated lights, they are not built as automated lighting consoles. ETC is primarily a theatrical lighting company, and thus their current consoles do a very good job of controlling theatrical lighting systems. They are designed with such features as single cuelist playback and lots of submasters for you to play with. High End/FPS, on the other hand, builds consoles designed for automated lighting with features such as pallets, many simultaneous cuelist playback, and multi-parameter fixtures. You really wouldn't put an Expression on a summer concert tour; likewise getting a Broadway production running solely off of a Hog III would be a really hard sell.
As was suggested and confirmed by boo52, this sort of problem would fall into the “audio server failure” category, most likely a hard drive crash. Most hard drive based audio playback boxes out there cash the music into RAM 1-2 seconds beforehand it’s needed, and the actual audio sample is then read out of RAM. The “skipping” you heard probably occurred because the hard drive stopped returning new samples (i.e. it “crashed”), and since nothing had been written into RAM to replace the old samples after the cashe had looped through once, they were read out again. Given this scenario, it could be hard to detect that something has gone wrong, as the box could have keep on generating timecode (this depends on how the systems is designed, sometimes people use a built-in timecode output, sometimes it’s recorded as a separate track; there are pros and cons to both setups).
I’m guessing that all the boxes that listen to timecode, such as the Hog, the FireOne system, and the AMX/show control system, probably are set to freewheel timecode if they’ve lost it, but systems were stopped manually after the situation was looked at. It would make sense to manually release everything on the Hog, as the lighting cues by themselves wouldn’t be very interesting without music, but keep the pyro going as fireworks sort of dazzle by themselves.
Somebody brought up the use of media servers for a show such as this. As MagliteL13 mentioned, buying a Catalyst server to playback audio is like buying a 747 for the peanuts. Although Catalyst can do audio, it is really designed to playback and manipulate video. There are a large number of products on the market that will do audio playback really well, and typically operate over Midi show control rather than DMX. However, catalyst is a very powerful tool, so I wouldn’t rule it out for some enhancements at some point down the road…
Disney does make extensive use of the Hog III rack mount unit, serving as both a stand-alone playback box and as a backup system. One thing to keep in mind is that these productions are constantly evolving, so I bet you’d be surprised how often things are changed/deleted/added.
BTW basically all the non-automated lighting at Disney is controlled by ETC sensor racks on the back end.
If you are interested in this kind of discussion/technical info, I would suggest checking out the LightNetwork at
http://www.lightnetwork.com/ . It's full of lots of good people who, if they don't know the answer to a question, usually know somebody who does.
Cheers everybody!
-Chris