I recently bought a HT OMEGA STRIKER 7.1 Channels 24-bit 96KHz PCI Interface Sound Card from newegg.com to replace my old SBLive 5.1.
Even that SBLive supports electrical SPDIF out and the sound quality is quite good, it does it only for 2 channels. So I bought the Striker for it's CMI8770 chipset that supports Dolby Digital Live Real-Time Content Encoder and DTS CONNECT for 8 channels, at least this is what they say at newegg and other places on web.

But I found out that the latest KnoppMyth R5E50 doesn't find it as a true CMI8770 but as a CMI8738 model68. I'm not sure what this means it doesn't seem to be a CMI8768+ since it doesn't have any DolbyDigital controls.

I upgraded to the latest alsa, I played with different settings in the alsamixer but still it has the same level of functionality as my old SBLive. I don't know what else to do, I seriously consider sending it back.

Did any of you have had success with a CMI8770 card or at least any other card that outputs DolbyDigital or DTS on 6 or more channels? What I'm trying to achieve is to be able to send the HD 5.1 sound from my HD-3000 to my receiver.

Thanks,
fx

Finally I got it to work, at least partially:

First playing music was working but recorded shows from analog card played without sound.
mplayer -ao alsa:device=hw=0.2 was also working on the digital out

After finding the post at: http://mysettopbox.tv/phpBB2/viewtopic. ... t878+sound

I added the following line to /etc/modprobe.d/alsa-base
options snd-pcm-oss adsp_map=2

changed Utilities/Setup/General Audio output device to /dev/adsp

Now music, recodings from analog card, digital channels and mplayer dvd:// play with sound.

Even " mplayer dvd:// -ac hwac3 " works nicely with DOLBY DIGITAL EX, but I couldn't make MythTV to work with AC3 passthrough. If I enable AC3 to SPDIF passthrough digital channels have no sound. Anybody had more luck with it?

One annoying thing is that the sound level is very high and changing the levels with alsamixer doesn't affect the output. Does anybody know how to change the level of /dev/adsp which is pointing to device 0.2?

I use both mplayer and xine with xine I just have it set to do pass though and that works fine. In mplayer I had to add a couple of lines to my mplayer config file:

ao=alsa
afm=hwac3,hwdts

I also had to download and install the codes for ac3 and dts. If you search for installing codes you should find a post that walks you thought it and the reinstall of mplayer with the new info.

That should do it.

_________________
Marty

Long live Myth and Knoppmyth!!!!!

Other teaks I did:

1. Recording from my analog WinTv card works with sound after I set it's audio device from /dev/adsp1. Still quality is poor, a loot of background noise. I tried all combinations in alsamixer no success, any suggestions on what I should try further?

2. I changed decoder library to libmpeg2, seems to use less cpu for HD and I can simultaneously record and play without hiccups.

3. I modified the settings for transcoder from MPEG2, bitrate from 2200 to 3000 but without scaling and now 1h recordings of 3-5 GB get transcoded to 1 GB, without visible loss of quality. As for audiom, the current transcoding has only 2 options MP3 or Uncompressed, I tried them both but no one keeps the original ac3 stream. Is there any way to keep the original ac3 audio track?

sinspot1: Can you give more details on what codes you downloaded and where from? Where the codecs to decode from or to encode to AC3/DTS ?

here is the post that I followed.

http://mysettopbox.tv/phpBB2/viewtopic. ... cs+mplayer


They are to decode AC/3 and DTS

_________________
Marty

Long live Myth and Knoppmyth!!!!!