Add device autodetection

Original commit message from CVS:
Add device autodetection

diff --git a/sys/v4l2/gstv4l2element.c b/sys/v4l2/gstv4l2element.c
index 45ae11c..c9a8118 100644 (file)
--- a/sys/v4l2/gstv4l2element.c
+++ b/sys/v4l2/gstv4l2element.c
@@ -21,11 +21,18 @@
 #include <config.h>
 #endif
 
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <unistd.h>
+
 #include "v4l2_calls.h"
 #include "gstv4l2tuner.h"
 #include "gstv4l2xoverlay.h"
 #include "gstv4l2colorbalance.h"
 
+#include <gst/propertyprobe/propertyprobe.h>
+
 /* elementfactory details */
 static GstElementDetails gst_v4l2element_details = {
        "Generic video4linux2 Element",
@@ -99,6 +106,163 @@ gst_v4l2_interface_init (GstInterfaceClass *klass)
 }
 
 
+static const GList *
+gst_v4l2_probe_get_properties (GstPropertyProbe *probe)
+{
+       GObjectClass *klass = G_OBJECT_GET_CLASS (probe);
+       static GList *list = NULL;
+
+       if (!list) {
+               list = g_list_append (NULL,
+                               g_object_class_find_property (klass, "device"));
+       }
+
+       return list;
+}
+
+static gboolean
+gst_v4l2_class_probe_devices (GstV4l2ElementClass *klass,
+                             gboolean             check)
+{
+       static gboolean init = FALSE;
+
+       if (!init && !check) {
+               gchar *dev_base[] = { "/dev/video", "/dev/v4l/video", NULL };
+               gint base, n, fd;
+
+               while (klass->devices) {
+                       GList *item = klass->devices;
+                       gchar *device = item->data;
+
+                       klass->devices = g_list_remove (klass->devices, item);
+                       g_free (device);
+               }
+
+               /* detect /dev entries */
+               for (n = 0; n < 64; n++) {
+                       for (base = 0; dev_base[base] != NULL; base++) {
+                               struct stat s;
+                               gchar *device = g_strdup_printf ("%s%d",
+                                                       dev_base[base], n);
+
+                               /* does the /dev/ entry exist at all? */
+                               if (stat (device, &s) == 0) {
+                                       /* yes: is a device attached? */
+                                       if ((fd = open (device, O_RDONLY)) > 0 ||
+                                           errno == EBUSY) {
+                                               if (fd > 0)
+                                                       close (fd);
+
+                                               klass->devices =
+                                                       g_list_append (klass->devices,
+                                                                      device);
+                                               break;
+                                       }
+                               }
+                               g_free (device);
+                       }
+               }
+
+               init = TRUE;
+       }
+
+       return init;
+}
+
+static void
+gst_v4l2_probe_probe_property (GstPropertyProbe *probe,
+                              guint             prop_id,
+                              const GParamSpec *pspec)
+{
+       GstV4l2ElementClass *klass = GST_V4L2ELEMENT_GET_CLASS (probe);
+
+       switch (prop_id) {
+               case ARG_DEVICE:
+                       gst_v4l2_class_probe_devices (klass, FALSE);
+                       break;
+               default:
+                       G_OBJECT_WARN_INVALID_PROPERTY_ID (probe, prop_id, pspec);
+                       break;
+       }
+}
+
+static gboolean
+gst_v4l2_probe_needs_probe (GstPropertyProbe *probe,
+                           guint             prop_id,
+                           const GParamSpec *pspec)
+{
+       GstV4l2ElementClass *klass = GST_V4L2ELEMENT_GET_CLASS (probe);
+       gboolean ret = FALSE;
+
+       switch (prop_id) {
+               case ARG_DEVICE:
+                       ret = !gst_v4l2_class_probe_devices (klass, TRUE);
+                       break;
+               default:
+                       G_OBJECT_WARN_INVALID_PROPERTY_ID (probe, prop_id, pspec);
+                       break;
+       }
+
+       return ret;
+}
+
+static GValueArray *
+gst_v4l2_class_list_devices (GstV4l2ElementClass *klass)
+{
+       GValueArray *array;
+       GValue value = { 0 };
+       GList *item;
+
+       if (!klass->devices)
+               return NULL;
+
+       array = g_value_array_new (g_list_length (klass->devices));
+       item = klass->devices;
+       g_value_init (&value, G_TYPE_STRING);
+       while (item) {
+               gchar *device = item->data;
+
+               g_value_set_string (&value, device);
+               g_value_array_append (array, &value);
+
+               item = item->next;
+       }
+       g_value_unset (&value);
+
+       return array;
+}
+
+static GValueArray *
+gst_v4l2_probe_get_values (GstPropertyProbe *probe,
+                          guint             prop_id,
+                          const GParamSpec *pspec)
+{
+       GstV4l2ElementClass *klass = GST_V4L2ELEMENT_GET_CLASS (probe);
+       GValueArray *array = NULL;
+
+       switch (prop_id) {
+               case ARG_DEVICE:
+                       array = gst_v4l2_class_list_devices (klass);
+                       break;
+               default:
+                       G_OBJECT_WARN_INVALID_PROPERTY_ID (probe, prop_id, pspec);
+                       break;
+       }
+
+       return array;
+}
+
+
+static void
+gst_v4l2_property_probe_interface_init (GstPropertyProbeInterface *iface)
+{
+       iface->get_properties = gst_v4l2_probe_get_properties;
+       iface->probe_property = gst_v4l2_probe_probe_property;
+       iface->needs_probe    = gst_v4l2_probe_needs_probe;
+       iface->get_values     = gst_v4l2_probe_get_values;
+}
+
+
 GType
 gst_v4l2element_get_type (void)
 {
@@ -137,6 +301,11 @@ gst_v4l2element_get_type (void)
                        NULL,
                        NULL,
                };
+               static const GInterfaceInfo v4l2_propertyprobe_info = {
+                       (GInterfaceInitFunc) gst_v4l2_property_probe_interface_init,
+                       NULL,
+                       NULL,
+               };
 
                v4l2element_type =
                        g_type_register_static(GST_TYPE_ELEMENT,
@@ -154,6 +323,9 @@ gst_v4l2element_get_type (void)
                g_type_add_interface_static (v4l2element_type,
                                             GST_TYPE_COLOR_BALANCE,
                                             &v4l2_colorbalance_info);
+               g_type_add_interface_static (v4l2element_type,
+                                            GST_TYPE_PROPERTY_PROBE,
+                                            &v4l2_propertyprobe_info);
        }
 
        return v4l2element_type;
@@ -193,7 +365,9 @@ static void
 gst_v4l2element_base_init (GstV4l2ElementClass *klass)
 {
        GstElementClass *gstelement_class = GST_ELEMENT_CLASS (klass);
-  
+
+       klass->devices = NULL;
+
        gst_element_class_set_details (gstelement_class,
                                       &gst_v4l2element_details);
 }

diff --git a/sys/v4l2/gstv4l2element.h b/sys/v4l2/gstv4l2element.h
index 23d379e..a57f66f 100644 (file)
--- a/sys/v4l2/gstv4l2element.h
+++ b/sys/v4l2/gstv4l2element.h
@@ -51,6 +51,8 @@
                (G_TYPE_CHECK_INSTANCE_TYPE((obj), GST_TYPE_V4L2ELEMENT))
 #define GST_IS_V4L2ELEMENT_CLASS(obj) \
                (G_TYPE_CHECK_CLASS_TYPE((klass), GST_TYPE_V4L2ELEMENT))
+#define GST_V4L2ELEMENT_GET_CLASS(obj) \
+               (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_V4L2ELEMENT, GstV4l2ElementClass))
 
 
 typedef        struct _GstV4l2Element          GstV4l2Element;
@@ -87,6 +89,9 @@ struct _GstV4l2Element {
 struct _GstV4l2ElementClass {
        GstElementClass parent_class;
 
+       /* probed devices */
+       GList *devices;
+
        /* signals */
        void     (*open)            (GstElement  *element,
                                     const gchar *device);