gstreamer/ext/alsa/gstalsamixertrack.c

/* ALSA mixer track implementation.
 * Copyright (C) 2003 Leif Johnson <leif@ambient.2y.net>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "gstalsamixertrack.h"

static void gst_alsa_mixer_track_init (GstAlsaMixerTrack * alsa_track);
static void gst_alsa_mixer_track_class_init (gpointer g_class,
    gpointer class_data);

static GstMixerTrackClass *parent_class = NULL;

GType
gst_alsa_mixer_track_get_type (void)
{
  static GType track_type = 0;

  if (!track_type) {
    static const GTypeInfo track_info = {
      sizeof (GstAlsaMixerTrackClass),
      NULL,
      NULL,
      gst_alsa_mixer_track_class_init,
      NULL,
      NULL,
      sizeof (GstAlsaMixerTrack),
      0,
      (GInstanceInitFunc) gst_alsa_mixer_track_init,
    };

    track_type =
	g_type_register_static (GST_TYPE_MIXER_TRACK, "GstAlsaMixerTrack",
	&track_info, 0);
  }

  return track_type;
}

static void
gst_alsa_mixer_track_class_init (gpointer g_class, gpointer class_data)
{
  if (parent_class == NULL)
    parent_class = g_type_class_ref (GST_TYPE_MIXER_TRACK);
}

static void
gst_alsa_mixer_track_init (GstAlsaMixerTrack * alsa_track)
{
}

GstMixerTrack *
gst_alsa_mixer_track_new (snd_mixer_elem_t * element,
    gint track_num, gint channels, gint flags)
{
  gint i;
  long min, max;

  GstMixerTrack *track = g_object_new (GST_ALSA_MIXER_TRACK_TYPE, NULL);
  GstAlsaMixerTrack *alsa_track = (GstAlsaMixerTrack *) track;

  /* set basic information */
  track->label = g_strdup_printf ("%s", snd_mixer_selem_get_name (element));
  track->num_channels = channels;
  track->flags = flags;
  alsa_track->element = element;
  alsa_track->track_num = track_num;

  /* set volume information */
  snd_mixer_selem_get_playback_volume_range (element, &min, &max);
  track->min_volume = (gint) min;
  track->max_volume = (gint) max;

  snd_mixer_selem_get_capture_volume_range (element, &min, &max);
  alsa_track->min_rec_volume = (gint) min;
  alsa_track->max_rec_volume = (gint) max;

  for (i = 0; i < channels; i++) {
    long tmp;

    if (snd_mixer_selem_has_playback_channel (element, i)) {
      snd_mixer_selem_get_playback_volume (element, i, &tmp);
      alsa_track->volumes[i] = (gint) tmp;
    } else if (snd_mixer_selem_has_capture_channel (element, i)) {
      snd_mixer_selem_get_capture_volume (element, i, &tmp);
      alsa_track->volumes[i] = (gint) tmp;
    }
  }

  return track;
}