[alsa-devel] Test device for automated testing
Hi everybody,
we're currently writing a lot of ALSA user space applications. In order to test this code with our unit testing and other test environments we'd like to know if there's a dummy PCM device which provides the fundamental operations like reading/writing and setting the common hardware parameters. It doesn't even have to supply some useful functionality like loop back or similar.
Neither the docs nor the goo led us to something useful.
Thanks and regards Uli
Uli Franke wrote:
we're currently writing a lot of ALSA user space applications. In order to test this code with our unit testing and other test environments we'd like to know if there's a dummy PCM device which provides the fundamental operations like reading/writing and setting the common hardware parameters.
That would be the snd-dummy module.
If you cannot load kernel drivers, you could try the virtual "null" device, but that one does not have realistic timing.
Regards, Clemens
On 16.09.2015 14:59, Clemens Ladisch wrote:
Uli Franke wrote:
we're currently writing a lot of ALSA user space applications. In order to test this code with our unit testing and other test environments we'd like to know if there's a dummy PCM device which provides the fundamental operations like reading/writing and setting the common hardware parameters.
That would be the snd-dummy module.
Great - that's what we're looking for. I'll check it out.
If you cannot load kernel drivers, you could try the virtual "null" device, but that one does not have realistic timing.
I tried the "null" but this fails when setting hw parameters with an assertion.
Regards Uli
Uli Franke wrote:
I tried the "null" but this fails when setting hw parameters with an assertion.
In theory, the null device does not have any restrictions. But an assertion indicates a programming error (somewhere). What is the message, and what are the hw parameters?
Regards, Clemens
On 16.09.2015 16:30, Clemens Ladisch wrote:
Uli Franke wrote:
I tried the "null" but this fails when setting hw parameters with an assertion.
In theory, the null device does not have any restrictions. But an assertion indicates a programming error (somewhere). What is the message, and what are the hw parameters?
The assertion fails with
pcm_params.c:2360: _snd_pcm_hw_params_internal: Assertion `err >= 0' failed.
There's only a single result on google [1] which discusses this assertion but the thread doesn't result in any meaningful conclusion.
I assembled a small test program which causes this very assertion to fail.
#include <alsa/asoundlib.h>
int main () { snd_pcm_hw_params_t *params; snd_pcm_t *pcm;
snd_pcm_open(&pcm, "null", SND_PCM_STREAM_PLAYBACK, 0); snd_pcm_hw_params_malloc(¶ms); snd_pcm_hw_params_any(pcm, params); snd_pcm_hw_params(pcm, params);
return 0; }
I appended some system specs [2] (in case you should need more, just let me know).
Regards Uli
____ [1] http://sourceforge.net/p/cmus/mailman/message/32707782/ [2] System specs:
uli@ankerklause:~/.../dlna/wdmr$ uname -a Linux ankerklause 3.16.0-46-generic #62~14.04.1-Ubuntu SMP Tue Aug 11 16:28:19 UTC 2015 i686 i686 i686 GNU/Linux
uli@ankerklause:~/.../dlna/wdmr$ aptitude show libasound2 Package: libasound2 State: installed Automatically installed: yes Multi-Arch: same Version: 1.0.27.2-3ubuntu7 Priority: optional Section: libs Maintainer: Ubuntu Developers ubuntu-devel-discuss@lists.ubuntu.com Architecture: i386 Uncompressed Size: 1'208 k Depends: libc6 (>= 2.16), libasound2-data (>= 1.0.27.2-3ubuntu7) PreDepends: multiarch-support Suggests: libasound2-plugins (>= 1.0.24) Breaks: bluez-alsa (<= 4.94-2), libasound2-plugin-equal (<= 0.6-1), libasound2-plugins (< 1.0.24) Provided by: liboss4-salsa-asound2 Description: shared library for ALSA applications This package contains the ALSA library and its standard plugins, as well as the required configuration files.
ALSA is the Advanced Linux Sound Architecture. Homepage: http://www.alsa-project.org/
participants (2)
-
Clemens Ladisch -
Uli Franke