[linux-audio-dev] RME Hammerfall DSP Cardbus+Multiface

Paul Davis paul at linuxaudiosystems.com
Thu Dec 19 11:00:00 UTC 2002


>Hmm I do use line_outs_monitor=1 as a module option on loading snd-hdsp. 

by editing /etc/modules.conf or its equivalent on your system, and
adding:

	options snd_hdsp line_outs_monitor=1

this will take effect the next time the snd-hdsp driver is loaded.

>gamix shows that all the channel volumes are loud enough....The various 
>'play' (aplay, etc) doesnt complain (keeps on playing stuff without 
>falling out) yet all I hear is silence.
>
>gamix shows the 'passthrough" to be disabled. Is that some indication of 
>whats going on?

no, i told you already: if line_outs_monitor isn't set to a non-zero
value, then *nothing* will be routed out of the line out channels. if
its set to a non-zero value, then all playback and input channels will
be sent to the 2 line out channels at unity gain, mapped using a
conventional stereo setup.

the only controls that gamix shows are a small set created
specifically to allow limited control from the existing set of linux
"mixer" apps. they control *only* the volume of the computer-generated
data stream (0..N) sent to the matching output (0..N). they do not
affect any other aspect of this extremely powerful mixer.

>How do I play something out through the SPDIF/optical or ADAT ports?

you have to define this question more precisely. using the "plughw"
device will duplicate the signals across all channels. its extremely
unlikely you can use the "hw" method, since this requires
non-interleaved, 24-in-32 bit, 26 channel sound, and i doubt you have
any files like this on your system. this is a generic ALSA question,
and one that needs (like most of ALSA) to be better documented. the
"hw" access method requires a hardware configuration (sample rate,
sample bit width, interleaving, channel count) that is directly
supported by the hardware - no format conversion is done by ALSA at
all. by contrast, the "plughw" access method will convert between just
about any requested format (eg. stereo 16 bit interleaved data) and
something supported by the hardware. i repeat: this has nothing to do
with the hammerfall - it applies to all ALSA support devices. the same
is true about the methods of defining devices corresponding to
specific output channels. this is a generic ALSA question, and i don't
have time right now to answer it.

--p



More information about the Linux-audio-dev mailing list