Sudden loss of DD sound from SPDIF passthrough (1 Viewer)

[Joe G]

I have been using PowerDvd 4.0 on an XP Home SP1 system, using the SPDIF output for all of my PC audio. I have been able to get DD 5.1 out of it with no problems for months. PowerDvd has been passing the AC3 sound directly out the SPDIF output of my Soundblaster Live card.

Suddenly this week, without me changing anything, I get no DD sound. The other audio still comes out of the digital output: Windows noises, CD audio, MPEG2 playback; all of which are stereo sound, not DD.
If I change the PowerDvd setting from "Use SPDIF" to "stereo", then I get sound, but it is now in stereo, not DD (of course).
It is a dual-boot system, and both partitions show the same behavior. That shows that I didn't change anything.

I don't want to go installing AC3filter or do other radical things until I find out what's going on.

Has anyone else experienced this? A sudden loss of capability on a previously working system?

Is there a codec/filter that has an expiration date or something?

search terms: AC3 DD 5.1 Dolby Digital SPDIF S/PDIF PowerDvd no sound DVD problem XP

 

[Scott Shanks]

In the surround mixer you have to make sure that the check box to bypass AC3 decoder is checked.