overdue-scratch

Author Topic: AC3/DTS Passthrough over S/PDIF not working. ALC1200 on Asus P5Q-EM  (Read 2488 times)

0 Members and 1 Guest are viewing this topic.

gaspimp

  • Entrant
  • Posts: 1
Applications like VLC do not detect S/PDIF as supporting AC3 Passthrough. Instead the audio gets decoded and sent as 2 channel PCM. I'm not sure exactly where this would be implemented but I'm guessing the driver has to publicize that it supports AC3 and PCM instead of just PCM.

I should add that if anyone has any ideas I'd be more than happy to make source code modifications and test. I poked around a bit and it appears that apple uses 2 different constants for AC3, the AC3 one is "ac-3" and there's another one ...1937AC3 which maps to "cac3". I read that cac3 is the right format for bitstreaming but VoodooHDA does not make reference to it. Anyway I'm certainly no expert so help would be greatly appreciated!
« Last Edit: August 31, 2009, 01:28:30 AM by gaspimp »