#624: need proper support for Terratec EWS88-MT (ice1712)
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Reporter: aelschuring | Owner: lennart
Type: defect | Status: new
Milestone: | Component: module-alsa-*
Resolution: | Keywords: ews88 profile-set
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Comment(by lennart):
Replying to [comment:28 aelschuring]:
> I've posted a patch on alsa-devel today to at least get the patch for
front:0 merged. I'm also experimenting with a solution that will allow PA
and other applications to access front: and spdif: at the same time, which
is currently not possible because any access to one of the channels will
cause the entire device to be locked. That's a fundamental property of
ALSA, and I think any solution I can come up with will be hackish.
Depending on something like dmix for this woulde certainly be suboptimal.
I must really say the ICE1712 design is really awful. ;-)
> Is there a difference between the iec958: and spdif: devices? Because
currently the card defines only the first of the two.
>
> We could probably ask for fourch: and sixch: definitions, but I don't
think the ALSA guys will really like them. At least they do make more
sense than surround* definitions, but there is just one minor issue: ALSA
uses one configuration file for all ice1712 cards (no subsystem-id
separation possible in ALSA), so I'm really hoping to keep that file as
generic as possible: I'm currently leaning towards only three devices,
which are front:, spdif: and an all-channel (8) definition.
But it sucks a bit that you have to open an 8ch stream on a device that
only has 4ch plugs actually soldered on.
But then again, at some level we need to add the additional null channels.
And I guess that work should be done at one place and one place only.
Since PA already does some channel rearrangements it probably does make
sense to export the audio device as 8ch device to PA and then have PA
synthesize the extra null channels, however not expose them for volume
control and suchlike.
Currently PA assumes that the channels of the PCM stream it sends to the
device and the channels of the volume control it exposes for that are
identical. I guess it is time to end that and disuitnighs both channel
maps. In this case we might have more streams in the PCM stream than we
want to show in the mixer UI. And for some devices the other way round is
true as well (i.e. stereo stream with 2.1 volume control for LFE).
So I have now added another item to my todo list: to make that destinction
between volume and PCM channel maps.
--
Ticket URL: <http://pulseaudio.org/ticket/624#comment:29>
PulseAudio <http://pulseaudio.org/>
The PulseAudio Sound Server
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