--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gst_plugins_base/ext/alsa/gstalsadeviceprobe.c	Wed Sep 01 12:16:41 2010 +0100
@@ -0,0 +1,208 @@
+/* Copyright (C) 2001 CodeFactory AB
+ * Copyright (C) 2001 Thomas Nyberg <thomas@codefactory.se>
+ * Copyright (C) 2001-2002 Andy Wingo <apwingo@eos.ncsu.edu>
+ * Copyright (C) 2003 Benjamin Otte <in7y118@public.uni-hamburg.de>
+ * Copyright (C) 2005 Tim-Philipp Müller <tim centricular 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "gstalsadeviceprobe.h"
+#include "gst/interfaces/propertyprobe.h"
+
+static const GList *
+gst_alsa_device_property_probe_get_properties (GstPropertyProbe * probe)
+{
+  GObjectClass *klass = G_OBJECT_GET_CLASS (probe);
+  static GList *list = NULL;
+
+  /* well, not perfect, but better than no locking at all.
+   * In the worst case we leak a list node, so who cares? */
+  GST_CLASS_LOCK (GST_OBJECT_CLASS (klass));
+
+  if (!list) {
+    GParamSpec *pspec;
+
+    pspec = g_object_class_find_property (klass, "device");
+    list = g_list_append (NULL, pspec);
+  }
+
+  GST_CLASS_UNLOCK (GST_OBJECT_CLASS (klass));
+
+  return list;
+}
+
+static GList *
+gst_alsa_get_device_list (snd_pcm_stream_t stream)
+{
+  snd_ctl_t *handle;
+  int card, err, dev;
+  snd_ctl_card_info_t *info;
+  snd_pcm_info_t *pcminfo;
+  gboolean mixer = (stream == -1);
+  GList *list = NULL;
+
+  if (stream == -1)
+    stream = 0;
+
+  snd_ctl_card_info_malloc (&info);
+  snd_pcm_info_malloc (&pcminfo);
+  card = -1;
+
+  if (snd_card_next (&card) < 0 || card < 0) {
+    /* no soundcard found */
+    return NULL;
+  }
+
+  while (card >= 0) {
+    gchar name[32];
+
+    g_snprintf (name, sizeof (name), "hw:%d", card);
+    if ((err = snd_ctl_open (&handle, name, 0)) < 0) {
+      goto next_card;
+    }
+    if ((err = snd_ctl_card_info (handle, info)) < 0) {
+      snd_ctl_close (handle);
+      goto next_card;
+    }
+
+    if (mixer) {
+      list = g_list_append (list, g_strdup (name));
+    } else {
+      dev = -1;
+      while (1) {
+        gchar *gst_device;
+
+        snd_ctl_pcm_next_device (handle, &dev);
+
+        if (dev < 0)
+          break;
+        snd_pcm_info_set_device (pcminfo, dev);
+        snd_pcm_info_set_subdevice (pcminfo, 0);
+        snd_pcm_info_set_stream (pcminfo, stream);
+        if ((err = snd_ctl_pcm_info (handle, pcminfo)) < 0) {
+          continue;
+        }
+
+        gst_device = g_strdup_printf ("hw:%d,%d", card, dev);
+        list = g_list_append (list, gst_device);
+      }
+    }
+    snd_ctl_close (handle);
+  next_card:
+    if (snd_card_next (&card) < 0) {
+      break;
+    }
+  }
+
+  snd_ctl_card_info_free (info);
+  snd_pcm_info_free (pcminfo);
+
+  return list;
+}
+
+static void
+gst_alsa_device_property_probe_probe_property (GstPropertyProbe * probe,
+    guint prop_id, const GParamSpec * pspec)
+{
+  if (!g_str_equal (pspec->name, "device")) {
+    G_OBJECT_WARN_INVALID_PROPERTY_ID (probe, prop_id, pspec);
+  }
+}
+
+static gboolean
+gst_alsa_device_property_probe_needs_probe (GstPropertyProbe * probe,
+    guint prop_id, const GParamSpec * pspec)
+{
+  /* don't cache probed data */
+  return TRUE;
+}
+
+static GValueArray *
+gst_alsa_device_property_probe_get_values (GstPropertyProbe * probe,
+    guint prop_id, const GParamSpec * pspec)
+{
+  GstElementClass *klass;
+  const GList *templates;
+  snd_pcm_stream_t mode = -1;
+  GValueArray *array;
+  GValue value = { 0, };
+  GList *l, *list;
+
+  if (!g_str_equal (pspec->name, "device")) {
+    G_OBJECT_WARN_INVALID_PROPERTY_ID (probe, prop_id, pspec);
+    return NULL;
+  }
+
+  klass = GST_ELEMENT_GET_CLASS (GST_ELEMENT (probe));
+
+  /* I'm pretty sure ALSA has a good way to do this. However, their cool
+   * auto-generated documentation is pretty much useless if you try to
+   * do function-wise look-ups. */
+  /* we assume one pad template at max [zero=mixer] */
+  templates = gst_element_class_get_pad_template_list (klass);
+  if (templates) {
+    if (GST_PAD_TEMPLATE_DIRECTION (templates->data) == GST_PAD_SRC)
+      mode = SND_PCM_STREAM_CAPTURE;
+    else
+      mode = SND_PCM_STREAM_PLAYBACK;
+  }
+
+  list = gst_alsa_get_device_list (mode);
+
+  if (list == NULL) {
+    GST_LOG_OBJECT (probe, "No devices found");
+    return NULL;
+  }
+
+  array = g_value_array_new (g_list_length (list));
+  g_value_init (&value, G_TYPE_STRING);
+  for (l = list; l != NULL; l = l->next) {
+    GST_LOG_OBJECT (probe, "Found device: %s", (gchar *) l->data);
+    g_value_take_string (&value, (gchar *) l->data);
+    l->data = NULL;
+    g_value_array_append (array, &value);
+  }
+  g_value_unset (&value);
+  g_list_free (list);
+
+  return array;
+}
+
+static void
+gst_alsa_property_probe_interface_init (GstPropertyProbeInterface * iface)
+{
+  iface->get_properties = gst_alsa_device_property_probe_get_properties;
+  iface->probe_property = gst_alsa_device_property_probe_probe_property;
+  iface->needs_probe = gst_alsa_device_property_probe_needs_probe;
+  iface->get_values = gst_alsa_device_property_probe_get_values;
+}
+
+void
+gst_alsa_type_add_device_property_probe_interface (GType type)
+{
+  static const GInterfaceInfo probe_iface_info = {
+    (GInterfaceInitFunc) gst_alsa_property_probe_interface_init,
+    NULL,
+    NULL,
+  };
+
+  g_type_add_interface_static (type, GST_TYPE_PROPERTY_PROBE,
+      &probe_iface_info);
+}