From: Howard Abrams <abramsh@acm.org>
To: Mark Rages <markrages@mlug.missouri.edu>
Cc: alsa-devel@alsa-project.org
Subject: Re: Simple ALSA capture/playback example and help wanted
Date: Thu, 28 Mar 2002 21:05:31 -0800 [thread overview]
Message-ID: <3CA3F61B.9080302@acm.org> (raw)
In-Reply-To: 20020328220648.A18690@mlug.missouri.edu
Thanks Mark. I'll take a look at jack, but in the near-term, I
copied a sample from a link off your page. It must have been
from a earlier rev of the api, but it only required very minimal
changes to compile.
The program I used was "A Minimal Full-Duplex Program", off the
page: http://www.op.net/~pbd/alsa-audio.html#duplexex
It's real basic, similar to what I had tried before. However, if
I using the 'spdif' device I run into the same problem:
ALSA lib setup.c:94:(snd_sctl_install) Cannot lock ctl elem
duplex: pcm.c:847: snd_pcm_prepare: Assertion `pcm->setup' failed.
If I use the 'plughw:0,2' device, the program returns immediately,
unless there is no audio on the spdif line, in which case it
hangs.
To me, it looks like the driver has a problem with full-duplex. Is
that correct? Again I'm using a Midiman DiO 2448 (cmipci driver).
Thanks again,
h.
Mark Rages wrote:
> There are several examples, but out of hubris I'll point you to my webpage: (all the examples are linked from the top)
>
> http://mlug.missouri.edu/~markrages/wiki/index.php?WritingAnAlsaClient
>
> In particular, I'd recommend you jook at JACK (jackit.sourceforge.net) before worrying too much about the ALSA details.
>
> Regards,
> Mark
> markrages@mlug.missouril.edu
>
>
>>All,
>>
>>I'm new to ALSA, and I'm using whatever version is in the
>>2.5.7 kernel w/ a Midiman Dio 2448 (cmipci driver).
>>
>>I'm trying to write a simple app that reads some samples,
>>does a small bit of processing, and writes them back out
>>to the same device.
>>
>>The card is full duplex, but I cannot seem to open a pcm
>>device for reading and writing at the same time. Even the
>>"latency.c" doesn't work. Is the driver just broke?
>>
>>Two questions:
>>
>>1. What is the best way to accomplish my task?
>>
>>2. Does anyone have a simple example to do this?
>>
>>Thanks,
>>
>>h.
>>
>>
>>_______________________________________________
>>Alsa-devel mailing list
>>Alsa-devel@lists.sourceforge.net
>>https://lists.sourceforge.net/lists/listinfo/alsa-devel
>>
>
> _______________________________________________
> Alsa-devel mailing list
> Alsa-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/alsa-devel
>
>
next prev parent reply other threads:[~2002-03-29 5:06 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-03-29 2:24 Simple ALSA capture/playback example and help wanted Howard Abrams
2002-03-29 4:06 ` Mark Rages
2002-03-29 5:05 ` Howard Abrams [this message]
2002-03-29 5:49 ` Mark Rages
2002-03-29 6:19 ` Howard Abrams
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=3CA3F61B.9080302@acm.org \
--to=abramsh@acm.org \
--cc=alsa-devel@alsa-project.org \
--cc=markrages@mlug.missouri.edu \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.