[mythtv-users] Anyone using a Chaintech AV-710 Sound Card?

[Ryan Pisani]

> On 10/25/07, Ryan Pisani <mythtv at frouse3.homelinux.com> wrote:
>> I bought a chaintech av-710 about 6 months ago, installed it, and got
>> basic analog functionality from it after a 1/2 day of screwing with it.
>> I recently upgraded my main backend/frontend to a new kernel and new
>> ALSA,
>> so I thought I'd take another stab at getting the optical (i'd take the
>> 3
>> pin surround if i had to) surround sound working.
>>
>> I can get 2 channel sound out of standard output and optical. However,
>> on
>> the optical side I cannot get PCM volume adjustments at all, it is one
>> constant volume no matter what I try....
>>
>>
>> My recordings are standard stereo, but I've seen other users with other
>> cards doing a sound duplication to simulate 5.1 surround. I'd like this
>> even for movies, but there is nothing I can seem to get working that
>> will
>> ouput to any other channels. speaker-test will also only output to 2
>> channels, no matter what I've tried.
>>
>> Anyhow, I bought this card because it seemed to have good alsa and linux
>> support, however, since owning it I've not found a single asound.conf
>> that
>> seems to produce what I'm after and no recent data posted scouring the
>> web.
>>
>> Is there anyone out there using this card? If so, can you send me your
>> asound.conf and asoundrc files?  Has anyone gotten or tried to get
>> simulated surround sound?
>>
>> The card is like $20.00 at newegg, so it's a good buy with spdif out and
>> both analog and optical 7.1 support if it indeed can be done with alsa.
>
>
> You are confusing AC3/DTS passthrough with the ability to generate
> realtime 5.1 or 7.1 sound.  There are only two sound cards on the
> market that support DTSLive or DDLive (generating 5.1 digital sound),
> and neither support linux.  The nforce2 onboard sound DOES support
> this, but isn't available in soundcard form.  Speaker test through
> digital out will NEVER do more than 2 channels.

I was under the impression that users out there have "simulated 5.1" sound
using a properly configured asoundrc file with a proper "route" function
in place to simulate 5.1.

Something like this from alsa.opensrc.org

pcm.jack51 {
    # "asym" allows for different
    # handling of in/out devices
    type asym
    playback.pcm {
         # route for mmap workaround
         type plug
         slave.pcm "surround51"
         slave.channels 6
         route_policy duplicate
    }
    capture.pcm {
        # 2 channels only
        type hw
        card 0
    }
}

I've seen other mention to this where guys have used timeing adjustments
in their route policy that does sound delays, etc to help simulate
duplicated surround.

I've tried to follow some of these examples but have come up empty handed
in the end.

http://alsa.opensrc.org/SurroundSound

I will definitly try the DVD suggestions just to see if works at all. What
about controlling volume level through PCM?


Thanks
Ryan


> To test that it's working use a DVD and be sure that AC3 and DTS
> passthrough are enabled.