capsfeatures: Add GST_CAPS_FEATURES_ANY

This is equal to any other caps features but results in unfixed caps. It
would be used by elements that only look at the buffer metadata or are
currently working in passthrough mode, and as such don't care about any
specific features.

docs/gst/gstreamer-sections.txt

@@ -459,6 +459,7 @@ gst_caps_intersect_mode_get_type
 GstCapsFeatures
 gst_caps_features_new
 gst_caps_features_new_empty
+gst_caps_features_new_any
 gst_caps_features_new_id
 gst_caps_features_new_id_valist
 gst_caps_features_new_valist
@@ -472,6 +473,7 @@ gst_caps_features_to_string
 gst_caps_features_set_parent_refcount
 
 gst_caps_features_is_equal
+gst_caps_features_is_any
 
 gst_caps_features_contains
 gst_caps_features_contains_id

gst/gstcaps.c

@@ -1075,12 +1075,17 @@ gboolean
 gst_caps_is_fixed (const GstCaps * caps)
 {
   GstStructure *structure;
+  GstCapsFeatures *features;
 
   g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
 
   if (GST_CAPS_LEN (caps) != 1)
     return FALSE;
 
+  features = gst_caps_get_features (caps, 0);
+  if (features && gst_caps_features_is_any (features))
+    return FALSE;
+
   structure = gst_caps_get_structure_unchecked (caps, 0);
 
   return gst_structure_foreach (structure, gst_caps_is_fixed_foreach, NULL);

gst/gstcapsfeatures.c

@@ -55,9 +55,11 @@ struct _GstCapsFeatures
   GType type;
   gint *parent_refcount;
   GArray *array;
+  gboolean is_any;
 };
 
 GType _gst_caps_features_type = 0;
+GstCapsFeatures *_gst_caps_features_any = NULL;
 GstCapsFeatures *_gst_caps_features_memory_system_memory = NULL;
 static GQuark _gst_caps_feature_memory_system_memory = 0;
 
@@ -82,6 +84,7 @@ _priv_gst_caps_features_initialize (void)
   g_value_register_transform_func (_gst_caps_features_type, G_TYPE_STRING,
       gst_caps_features_transform_to_string);
 
+  _gst_caps_features_any = gst_caps_features_new_any ();
   _gst_caps_features_memory_system_memory =
       gst_caps_features_new_id (_gst_caps_feature_memory_system_memory, 0);
 
@@ -148,12 +151,35 @@ gst_caps_features_new_empty (void)
   features->type = _gst_caps_features_type;
   features->parent_refcount = NULL;
   features->array = g_array_new (FALSE, FALSE, sizeof (GQuark));
+  features->is_any = FALSE;
 
   GST_TRACE ("created caps features %p", features);
 
   return features;
 }
 
+/**
+ * gst_caps_features_new_any:
+ *
+ * Creates a new, ANY #GstCapsFeatures. This will be equal
+ * to any other #GstCapsFeatures but caps with these are
+ * unfixed.
+ *
+ * Free-function: gst_caps_features_free
+ *
+ * Returns: (transfer full): a new, ANY #GstCapsFeatures
+ */
+GstCapsFeatures *
+gst_caps_features_new_any (void)
+{
+  GstCapsFeatures *features;
+
+  features = gst_caps_features_new_empty ();
+  features->is_any = TRUE;
+
+  return features;
+}
+
 /**
  * gst_caps_features_new:
  * @feature1: name of first feature to set
@@ -388,6 +414,11 @@ priv_gst_caps_features_append_to_gstring (const GstCapsFeatures * features,
 
   g_return_if_fail (features != NULL);
 
+  if (features->array->len == 0 && features->is_any) {
+    g_string_append (s, "ANY");
+    return;
+  }
+
   n = features->array->len;
   for (i = 0; i < n; i++) {
     GQuark *quark = &g_array_index (features->array, GQuark, i);
@@ -422,6 +453,11 @@ gst_caps_features_from_string (const gchar * features)
   if (!features || *features == '\0')
     return ret;
 
+  if (strcmp (features, "ANY") == 0) {
+    ret->is_any = TRUE;
+    return ret;
+  }
+
   /* Skip trailing spaces */
   while (*features == ' ')
     features++;
@@ -582,6 +618,9 @@ gst_caps_features_contains_id (const GstCapsFeatures * features, GQuark feature)
   g_return_val_if_fail (features != NULL, FALSE);
   g_return_val_if_fail (feature != 0, FALSE);
 
+  if (features->is_any)
+    return TRUE;
+
   n = features->array->len;
   if (n == 0)
     return feature == _gst_caps_feature_memory_system_memory;
@@ -612,6 +651,9 @@ gst_caps_features_is_equal (const GstCapsFeatures * features1,
   g_return_val_if_fail (features1 != NULL, FALSE);
   g_return_val_if_fail (features2 != NULL, FALSE);
 
+  if (features1->is_any || features2->is_any)
+    return TRUE;
+
   /* Check for the sysmem==empty case */
   if (features1->array->len == 0 && features2->array->len == 0)
     return TRUE;
@@ -636,6 +678,22 @@ gst_caps_features_is_equal (const GstCapsFeatures * features1,
   return TRUE;
 }
 
+/**
+ * gst_caps_features_is_any:
+ * @features: a #GstCapsFeatures.
+ *
+ * Returns %TRUE if @features is %GST_CAPS_FEATURES_ANY.
+ *
+ * Returns: %TRUE if @features is %GST_CAPS_FEATURES_ANY.
+ */
+gboolean
+gst_caps_features_is_any (const GstCapsFeatures * features)
+{
+  g_return_val_if_fail (features != NULL, FALSE);
+
+  return features->is_any;
+}
+
 /**
  * gst_caps_features_add:
  * @features: a #GstCapsFeatures.
@@ -649,6 +707,7 @@ gst_caps_features_add (GstCapsFeatures * features, const gchar * feature)
   g_return_if_fail (features != NULL);
   g_return_if_fail (IS_MUTABLE (features));
   g_return_if_fail (feature != NULL);
+  g_return_if_fail (!features->is_any);
 
   gst_caps_features_add_id (features, g_quark_from_string (feature));
 }
@@ -666,6 +725,7 @@ gst_caps_features_add_id (GstCapsFeatures * features, GQuark feature)
   g_return_if_fail (features != NULL);
   g_return_if_fail (IS_MUTABLE (features));
   g_return_if_fail (feature != 0);
+  g_return_if_fail (!features->is_any);
 
   if (!gst_caps_feature_name_is_valid (g_quark_to_string (feature))) {
     g_warning ("Invalid caps feature name: %s", g_quark_to_string (feature));

gst/gstcapsfeatures.h

@@ -35,6 +35,9 @@ typedef struct _GstCapsFeatures GstCapsFeatures;
 
 #define GST_CAPS_FEATURE_MEMORY_SYSTEM_MEMORY "memory:SystemMemory"
 
+GST_EXPORT GstCapsFeatures *_gst_caps_features_any;
+#define GST_CAPS_FEATURES_ANY (_gst_caps_features_any)
+
 GST_EXPORT GstCapsFeatures *_gst_caps_features_memory_system_memory;
 #define GST_CAPS_FEATURES_MEMORY_SYSTEM_MEMORY (_gst_caps_features_memory_system_memory)
 
@@ -42,6 +45,7 @@ GType             gst_caps_features_get_type (void);
 gboolean          gst_is_caps_features (gconstpointer obj);
 
 GstCapsFeatures * gst_caps_features_new_empty (void);
+GstCapsFeatures * gst_caps_features_new_any (void);
 GstCapsFeatures * gst_caps_features_new (const gchar *feature1, ...);
 GstCapsFeatures * gst_caps_features_new_valist (const gchar *feature1, va_list varargs);
 GstCapsFeatures * gst_caps_features_new_id (GQuark feature1, ...);
@@ -63,6 +67,8 @@ gboolean          gst_caps_features_contains (const GstCapsFeatures * features,
 gboolean          gst_caps_features_contains_id (const GstCapsFeatures * features, GQuark feature);
 gboolean          gst_caps_features_is_equal (const GstCapsFeatures * features1, const GstCapsFeatures * features2);
 
+gboolean          gst_caps_features_is_any (const GstCapsFeatures * features);
+
 void              gst_caps_features_add (GstCapsFeatures * features, const gchar * feature);
 void              gst_caps_features_add_id ( GstCapsFeatures * features, GQuark feature);
 

tests/check/gst/gstcapsfeatures.c

@@ -77,6 +77,20 @@ GST_START_TEST (test_from_to_string)
   gst_caps_features_free (a);
   gst_caps_features_free (b);
   g_free (str);
+
+  a = gst_caps_features_new_any ();
+  fail_unless (a != NULL);
+  fail_unless (gst_caps_features_is_any (a));
+  str = gst_caps_features_to_string (a);
+  fail_unless (str != NULL);
+  fail_unless_equals_string (str, "ANY");
+  b = gst_caps_features_from_string (str);
+  fail_unless (b != NULL);
+  fail_unless (gst_caps_features_is_equal (a, b));
+  fail_unless (gst_caps_features_is_any (b));
+  gst_caps_features_free (a);
+  gst_caps_features_free (b);
+  g_free (str);
 }
 
 GST_END_TEST;