Just to follow up on this prior post, I have now tried 3 different LiveCD based distributions that use ALSA and I get the same results on all of them. I also have not found any reports of anyone successfully passing through AC3 data from the Nvidia MCP51 online... this seems like I'm either missing a crucial setting that needs to be manually specified (which is what I think is most likely) or there is a bug in ALSA. I know for sure that my receiver can decode AC3 data. I'm not familiar with the process, should I be considering filing a bug tracker request with the ALSA project once I've performed more testing? Steve On Jan 15, 2009, at 10:59 AM, Steve Steffler wrote: > Hello, > > I have tried everything and as a last resort have decided to bug my > fellow ALSA users via this mailing list in the hope that someone can > help me with this problem. :) > > I am using ALSA on my MythTV (Knoppmyth) box. I have digital audio > working ALMOST perfectly for everything except AC3 passthrough. DTS > passthrough works fine and PCM works via SPDIF (however I am having > some issues there which I will describe later) > > The computer is running an Asus M2NPV-VM with an onboard Nvidia MCP51 > sound chip which uses Alsa's snd-hda-intel driver. > > When I attempt to play content (i.e. a DVD or a downloaded AC3 file) > with AC3 passthrough turned on, it appears to work, there are no error > messages in the logs of any of the programs I'm using (mplayer / > xine / vlc / mythfrontend), and the light indicating Dolby Digital > shows up on my audio receiver when I play AC3 content, but there is > silence.. When I play DTS content the DTS light lights up, and it > works perfectly in beautiful surround sound. > > The computer is running an Athlon64 4200+ chip and has 2GB ram. Here > is the information collected from my system by ALSA: > > http://www.alsa-project.org/db/?f=018a14b26ebf14c181a9bd064c77c5d05bfaa92b > > The other problem I am having is with PCM audio. It seems that PCM > audio only sounds "correct" on my digital receiver if I set up > an .asoundrc file that forces the bit-rate to 44100Hz. 48000Hz > results in the audio sounding slowed down and causes mythfrontend to > generate Buffer Underrun errors when I test with it. Does anyone have > the correct settings for this card? I know my receiver supports AC3 > and DTS in 48000 so it should be able to take a PCM signal at that > rate... :/ > > FYI the receiver on the other end is an LG HE903PAW. > > Does anyone have any tips? I have tried everything including > replacing ALSA completely, and I feel like I am very close to getting > this working 100%. > > Thanks in advance, > Steve > > > > ------------------------------------------------------------------------------ > This SF.net email is sponsored by: > SourcForge Community > SourceForge wants to tell your story. > http://p.sf.net/sfu/sf-spreadtheword > _______________________________________________ > Alsa-user mailing list > Alsa-user@xxxxxxxxxxxxxxxxxxxxx > https://lists.sourceforge.net/lists/listinfo/alsa-user ------------------------------------------------------------------------------ This SF.net email is sponsored by: SourcForge Community SourceForge wants to tell your story. http://p.sf.net/sfu/sf-spreadtheword _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
