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livetrax/libs/ardouralsautil/deviceparams.cc

89 lines
2.4 KiB
C++

/*
* Copyright (C) 2015 Robin Gareus <robin@gareus.org>
* Copyright (C) 2013 Paul Davis
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <alsa/asoundlib.h>
#include "pbd/convert.h"
#include "ardouralsautil/deviceinfo.h"
using namespace std;
int
ARDOUR::get_alsa_device_parameters (const char* device_name, const bool play, ALSADeviceInfo *nfo)
{
snd_pcm_t *pcm;
snd_pcm_hw_params_t *hw_params;
std::string errmsg;
int err;
nfo->valid = false;
err = snd_pcm_open (&pcm, device_name,
play ? SND_PCM_STREAM_PLAYBACK : SND_PCM_STREAM_CAPTURE,
SND_PCM_NONBLOCK);
if (err < 0) {
fprintf (stderr, "ALSA: Cannot open device '%s': %s\n", device_name, snd_strerror (err));
return 1;
}
snd_pcm_hw_params_alloca (&hw_params);
err = snd_pcm_hw_params_any (pcm, hw_params);
if (err < 0) {
errmsg = "Cannot get hardware parameters";
goto error_out;
}
err = snd_pcm_hw_params_get_channels_max (hw_params, &nfo->max_channels);
if (err < 0) {
errmsg = "Cannot get maximum channels count";
goto error_out;
}
err = snd_pcm_hw_params_get_rate_min (hw_params, &nfo->min_rate, NULL);
if (err < 0) {
errmsg = "Cannot get minimum rate";
goto error_out;
}
err = snd_pcm_hw_params_get_rate_max (hw_params, &nfo->max_rate, NULL);
if (err < 0) {
errmsg = "Cannot get maximum rate";
goto error_out;
}
err = snd_pcm_hw_params_get_buffer_size_min (hw_params, &nfo->min_size);
if (err < 0) {
errmsg = "Cannot get minimum buffer size";
goto error_out;
}
err = snd_pcm_hw_params_get_buffer_size_max (hw_params, &nfo->max_size);
if (err < 0) {
errmsg = "Cannot get maximum buffer size";
goto error_out;
}
snd_pcm_close (pcm);
nfo->valid = true;
return 0;
error_out:
fprintf (stderr, "ALSA: %s: %s\n", errmsg.c_str(), snd_strerror (err));
snd_pcm_close (pcm);
return 1;
}