After a week-long struggle, I finally solved my issue of recording SPDIF through my sound card. I've done this for years and for the first time I was having difficulty.

The issue was this. I connected my laserdisc player directly to my PC through the SPDIF-in. I hear the audio play while I play my LD. When I set it to record the digital audio through SPDIF-in, it records silence. If I fiddled with settings, I could get some audio, but it would cut in and out several times a second. Or the audio would just go silent.

It took me a week to figure out what was going on, but it finally dawned on me that perhaps it was happening on purpose. That's the only thing that made sense and I discovered the reasoning is content protection. Yes, the sound driver is designed to mute the SPDIF input if the "protected content" bit is set and it is being recorded.

What made me mad about this is that it took me a week to figure it out. And the only reason it took me a week is the fact that Windows gave no indication that it was silencing it for copy protection purposes.

The solution for me was to find and install a third party driver. I found two sites with third party drivers that ignore the copy protection bit in the SPDIF audio stream.

http://www.kxproject.com/

My sound card is a Creative Sound Blaster Audigy 2 V. I installed this new driver, did a little tweaking, and now digital SPDIF recording works flawlessly.

Darryl