2010-12-29, 20:01
alexrose1uk Wrote:If anyone has any ideas on my digital passthrough issue it'd be appreciated.
The debug snippet [I can post an entire log if it helps] confirms theres some sort of issue, but I have no idea whether the issue lies with FFDshow (I've tried a few different builds with no change), or the current build of DSPlayer (I'm currently using the 35694 build posted just a page or two back).
PCM output works fine 100% of the time for everything, but bitstream fails perhaps 50% of the time (and usually tends to end up crashing the DSPlayer component of XBMC so I have to restart), or thats what it feels like, the debug log tells me its not 'connecting' properly but doesnt really tell me *why*, especially as it DOES work some of the time.
Can you provide some details of your setup to make troubleshooting easier? I playback both AC3 and DTS exclusively with ffdshow in passthru mode without any issue whatsoever in XBMC (DSPlayer), MPC-HC and ZoomPlayer, so it's got to be something wrong with your hardware/setup.
I have a Gigabyte MA78GM-2SHP motherboard with onboard Realtek ALC889 audio (using the drivers from the realtek site), and use toslink (optical) out to a Yamaha RX-V463 AVR, and *never* have it fail. Ever. No matter what order stuff gets turned on. I can even turn offthe amp and back on repeatedly, switch inputs while playing, etc, and it always locks on to the bitstream without fail. It also bitstreams AC3 and DTS perfectly from XBMC's DVDPlayer and PowerDVD.
On the otherhand, I have my Xbox360 connected to the same AVR using HDMI, and that is way more finnicky. If the amp is on before the Xbox, then it will always fallback to PCM2.0, the Xbox has to be booted first to get the AVR and the Xbox to sync the 5.1 AC3 bitstream. HDMI handshaking is notoriously complicated and flakey, even with the best set-top boxes, let alone computers. Optical is definitely the way to go if you can.
I would suspect your sound card at first. Read this (entire) article from the author of AC3Filter - it explains the complicated process that sound cards have to manage to initialize a 5.1 bitstream, while interacting with system sounds, etc. he says some sound cards just don't do a good job of it:
http://ac3filter.net/guides/ac3filter_spdif
If you give me some details on what your setup consists of, maybe we can narrow it down to drivers, the soundcard, cabling, or your amplifier, because it surely isn't ffdshow or dsplayer.
Cheers
The REAL Joe