Hi Bill,
Sorry for the delay in response. Here's the output:
[root@audio-capture ~]# ls /dev/snd
by-path controlC0 controlC1 hwC0D2 hwC1D0 midiC1D0 midiC1D1 pcmC0D0c pcmC0D0p pcmC1D0c pcmC1D0p seq timer
[root@audio-capture ~]# ls /proc/asound/
card0 card1 cards default devices hwdep Intel modules oss pcm seq timers version
TIA.
On Fri, May 3, 2013 at 4:29 PM, Bill Unruh <unruh@xxxxxxxxxxxxxx> wrote:
On Fri, 3 May 2013, Vincent Gulinao wrote:Because my impression was that your soundcard had a large number (I chose 18
Thanks Bill,
The signals I need to record will come from multiple sources (radio
stations) that outputs stereo format, so I guess it means I'd need a "-c 2"
parameter in each of my arecord command then? In what cases is "-c 18" in
your example applicable?
as an example) of input channels. And that there is no way for the computer to
know which of those were paired together. All of my choices were illustrative
only to point out to you what to look for.
As I said, I have absolutely no idea about your soundcard, how it works, how
the driver for it works, etc. Maybe it puts out 16 different pairs and looks
to alsa like 16 different sound cards each with a stereo output. In which case
you would need a separate line for each. Or maybe it looks like one card with
32 channels. Or whatever.OK, change 16 and 32 above for 32 and 64. I have no idea. I have never seen such a card nor do I know anything about it.
More noob questions: how would arecord determine which channels exactly to
get its signals? This card supports up to 64 input channels, I assume not
Maybe.
all of them will be used at least in the beginning. Is this where the
asoundrc and/or "-D hw:.." comes into picture?
You say you have installed the card and have a driver for it. What do you get
when you do ls /dev/snd?
ls /proc/asound?
/ Vincent
On Thu, May 2, 2013 at 7:52 PM, Bill Unruh <unruh@xxxxxxxxxxxxxx> wrote:
On Thu, 2 May 2013, Vincent Gulinao wrote:
Hi everyone,
I have a task to setup a system that will continuously capture multiple
stereo signals using a MADI audio card (RME HDSPe MADI) and write them
into
files (perhaps in 1 hour chunks). Few checks I've learned while googling
on
the topic looks like that my linux setup seem to recognize the card at
least.
"Multiple Stereo signals" means what? I have no idea about the MADi
interface
or how alsa supports it. But if it does, it may be as simple as arecord
-Dhw:0 -c 18 -r 48000 -f SB24_LE output.wav
which would keep recording forever into output.wav. You could also use the
-d 3600 to tell it to record for exactly an hour. You
would then have to have a script to restart it to a different output file,
but
would miss a bit of the stream because of the time to stop and restart. I
vaguely recall a recording program that will automatically dump into a new
file every x secods, presumably not missing anything, but cannot remember
it
now.
(Note the above tells arecord to use the hardware input, not put it
through a
filter like rate changing etc, tells it you want 18 channels, a rate of
48000
samples per sec on each channel, and the input is in 24 bit format with Low
Order byte order.
I'm a total noob in ALSA and audio concepts in general. I've read many
docs
If you told us what you were trying to do, someone could probably offer
better
advice.
Note that the above assumes that you alsa does support the card without
problems and the card is card 0 on your system.
and forums (e.g. arecord, asoundrc, pulseaudio, jack, etc.) here and
there.--
But while I wait all those info settle in my mind, can somebody pitch here
some high-level hints on what things I need to know, or what sort of
questions should I be asking, to accomplish this task and make sure I'm on
the right direction?
Thanks in advance!
William G. Unruh | Canadian Institute for| Tel: +1(604)822-3273
Physics&Astronomy | Advanced Research | Fax: +1(604)822-5324
UBC, Vancouver,BC | Program in Cosmology | unruh@xxxxxxxxxxxxxx
Canada V6T 1Z1 | and Gravity | www.theory.physics.ubc.ca/
--
William G. Unruh | Canadian Institute for| Tel: +1(604)822-3273
Physics&Astronomy | Advanced Research | Fax: +1(604)822-5324
UBC, Vancouver,BC | Program in Cosmology | unruh@xxxxxxxxxxxxxx
Canada V6T 1Z1 | and Gravity | www.theory.physics.ubc.ca/
------------------------------------------------------------------------------ Learn Graph Databases - Download FREE O'Reilly Book "Graph Databases" is the definitive new guide to graph databases and their applications. This 200-page book is written by three acclaimed leaders in the field. The early access version is available now. Download your free book today! http://p.sf.net/sfu/neotech_d2d_may
_______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
