View Full Version : multicam problems

05-23-2004, 12:18 PM
This has been a rough weekend. I have 3 VX2000. I have tried 15-20 times to mix tapes in them using firewire /3 firewire cards/ vt switcher/ vt audiomixer with all audio inputs removed except from one camera. Capture panel set to program out/ DV video type 2/ Audio Uncompressed PCM. OS winxp pro/Supermicro Dual P4 Xeon 2.4/ Gig Ram DirectX 9. I dont start recording until all 3 tapes have been sync to the best of my ability. Have also started recording before I sync them up nothing. I have not been able to record over 6min before vt3 closes by itself. Error message sender pops up. Or every know and again out of sync message is notice in capture panel and then it shut down. Either way right before shutdown a still image will appear in VT vision. I've tried rebooting, killwinrtme, unplugging and replugging firewire and adapters before launching vt3 and trying it all over again. Please Help. There is such a wealth of knowledge here. I feel like such a pupil. Just call me Grasshopper.

Jim Capillo
05-23-2004, 01:14 PM
Well, I'll start with something simple. What kind of firewire cards do you have? I believe you need the TI chip on the cards to assure compatibility with VT. Someone else can confirm it, but I'll pull my card if necessary to check it. I remember reading it awhile ago, but am not absolutely sure......

Have you tried recording with just one deck, then two if one is successful? You might have another issue going on there. No packet writing software, right?

05-23-2004, 01:22 PM
I'm not surprised that wouldn't work, you were asking too much of your system, I shall explain.

First of all, since you said everything is on TAPE, WHY are you trying to do synchronized switching in the first place??? Just transfer the DV to your computer and do the editing in VT-Edit either manually or with a great program like Bob Tasa's MultiCamera Editor for VT-Edit.

The only time you would EVER want to attempt what you were trying is if you were trying to do LIVE switching with LIVE sources, and if this was the case, I would say to get an SX-8 and do it via analog, since there are way too many problems trying to do it all via firewire like that, and for a live camera situation, firewire would NOT be the highest quality way to do it anyway.

Though it's true that it has been said that VT[3] could do this type of thing with multiple firewire cards, I have not heard anyone actually succeed in doing it, so I really don't think it works.

As for why it specifically didn't work in your case, I can answer that. You were bringing in three DV sources to the switcher, at that point it uncompresses them to do switching, and then you were telling the capture panel to COMPRESS the result to DV and save it. NO WAY can your system support that. I have a dual-Xeon 2.8 and my system would choke on that, too. The only way this might work is if you were capturing to RTV, since that takes very little CPU resources to do.

It's unrealistic to expect to be able to uncompress THREE DV streams and recompress the result in real-time in software.

The theoretical switching of three DV sources that VT[3] "may" be capable of definately does NOT include compressing the result in real-time.

Jim Capillo
05-23-2004, 01:48 PM
That makes perfect sense Eugene - and is something I never thought of. Since I only have one deck and it is only controlled by firewire (the video comes in via Y/C), I would never experience that particular problem.