Trade Show A/V - 12 Days of Non-stop Playback for the Booth

Thomas C. Gass, Switzerland
November 2007

Beside my work for theatres, I'm also responsible for all audio related work at Visavista Ltd, a Swiss audiovisuals company specializing in business-to-business communications. Visavista came up with a project for Sekisui-Alveo, a producer of plastics mainly used in the automotive industry. The client wanted to be present at the world's largest trade fair for plastics, K2007, in Dusseldorf, Germany, and was looking for an eye-catcher for his booth. Visavista proposed a setup of 5 videostreams presented in synch on 5 different screens, showing pictures from Sekisiu-Alveo production sites in combination with emotional imagery fitting the overall setup of the booth, which had the look of a huge marine aquarium.

When evaluating the rental cost for the playback equipment (MPEG hardware players, timecode synchronization), our client was presented a estimate of 14000 Swiss francs (about 12,000 U.S. dollars). Quite an amount—so I wondered if this task couldn't be done with a Mac and QLab. I checked the QLab homepage, the user mailing list and with the help of Christopher, Marc Ray and Noah Mehl it was soon obvious that for much less money we could offer our customer a reliable system that could be used again on other fairs or for other A/V purposes—no more rental needed!

But first we had to get hold of a Mac Pro. There were no Mac Pros in stock and all dealers estimated a delivery within 4 to 8 weeks—far too long, since the opening of the fair in Dusseldorf was only five weeks away. Finally we found a dealer who promised to be able to deliver a Mac Pro already pre-equipped with three additional GForce video cards directly from Apple, Ireland—within five days.

When the machine arrived, we installed QLab and all licenses, and attached five displays. We did run into one problem—a bug in QuickTime 7.2 that prevented QLab from working on all three graphics cards—but thanks to Christopher we could identify the problem in no time and downgraded to QuickTime 7.1.6. [Editor's note: we found a work-around for this QuickTime bug, and it is no longer an issue.]

Our first test run with five screens was quite a success: 72 hours non-stop without any problems! There was one challenge, but with a little trick we could handle it: It was impossible to start all 5 streams at exactly the same time. What we did to solve the problem was rather easy: we added one second of black at the beginning of each stream, according to the stream's place in the start sequence. One second at the beginning of stream 1, two seconds at the beginning of stream 2, and so on. We then started all five streams starting with stream 5, then 4, all with a delay of 1 second after each, et voilà: everything was in synch—frame accurate! [Editor's note: QLab version 2 now offers guaranteed synchronization between video cues.]

Finally, an installation of "" made sure we could remote control the machine in case our customer had any problems.

  • Mac Pro
    • 2 x 3.0 GHz Dual-Core Intel Xeon 5100
    • 3 x NVIDIA GeForce 7300 GT with 256 MB GDDR2 SDRAM
    • 2 Serial-ATA Hard disks 7200 rpm, 500 GB (Raid)
    • 5GB RAM

[5 screens] [5 screens]

The day before the opening of the fair I myself installed and wired the system in Dusseldorf. Instructing our customer (who by the way never used a Mac before and of course was also not familiar with QLab!) took 5 minutes only. Needless to say, that the whole system ran 12 days non-stop, frame accurate and without any problems!

My next project is to implement QLab as main audio playback system in a theatre here in Basel. In addition, QLab will be connected to their Strand lighting console and also provide the projection of sub-titles for their opera productions.

The only thing I can say about QLab is: Great job, Figure 53! Thank you for a real masterpiece of software and for your fast and reliable support whenever needed! And last but not least: a big thank you to all the users on the list, providing lots of information, experience, help and new ideas about how to use QLab!