We have a new 8 core pac pro, Snow leopard 10.6.3, 6 GB RAM, with a new Decklink Studio card. Decklink 7.6 drivers. We are driving analogue Yamaha audio monitors, and a TVLogic HDSDI screen through a proper HDSDI cable.
We have an intermittent problem on this system: Occasionally the SDI signal breaks up. Playback stutters and simultaneously there is a loud hiss as full-range noise gets sent to the analogue monitors too. A flash of white noise is seen on the CANVAS and on the HDSDI monitor. This repeats at about five times per second while playing the timeline. Apple-F12 to switch off external video, and the problem stops immediately. The Canvas plays perfectly while the external monitor is off.
When we switch the external monitor on again (apple-F12) sometimes the problem goes away, and sometimes it re-occurs.
The first thing I suspected was the Decklink card, since I have many other decklink cards running on FCP. We replaced the card with a brand new card and the problem persists.
Two major differences between this system and out other, reliable decklink systems:
1. All our other decklink systems are on 10.5.8. New one is on 10.6.3.
2. Media - we are playing Sony XDCAM 1080i25 50mb/s media on a timeline with the same setting. Our other systems work with DV PAL and Prores HD codecs without issues.