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gstreamer/gst/gstcaps.h

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/* GStreamer
* Copyright (C) 2003 David A. Schleef <ds@schleef.org>
*
* 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., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#ifndef __GST_CAPS_H__
#define __GST_CAPS_H__
#include <gst/gstconfig.h>
#include <gst/gstminiobject.h>
#include <gst/gststructure.h>
#include <gst/gstcapsfeatures.h>
#include <gst/glib-compat.h>
G_BEGIN_DECLS
GST_EXPORT GType _gst_caps_type;
#define GST_TYPE_CAPS (_gst_caps_type)
#define GST_IS_CAPS(obj) (GST_IS_MINI_OBJECT_TYPE((obj), GST_TYPE_CAPS))
#define GST_CAPS_CAST(obj) ((GstCaps*)(obj))
#define GST_CAPS(obj) (GST_CAPS_CAST(obj))
#define GST_TYPE_STATIC_CAPS (gst_static_caps_get_type())
/**
* GstCapsFlags:
* @GST_CAPS_FLAG_ANY: Caps has no specific content, but can contain
* anything.
*
* Extra flags for a caps.
*/
typedef enum {
GST_CAPS_FLAG_ANY = (GST_MINI_OBJECT_FLAG_LAST << 0)
} GstCapsFlags;
/**
* GstCapsIntersectMode:
* @GST_CAPS_INTERSECT_ZIG_ZAG : Zig-zags over both caps.
* @GST_CAPS_INTERSECT_FIRST : Keeps the first caps order.
*
* Modes of caps intersection
*
* @GST_CAPS_INTERSECT_ZIG_ZAG tries to preserve overall order of both caps
* by iterating on the caps' structures as the following matrix shows:
* |[
* caps1
* +-------------
* | 1 2 4 7
* caps2 | 3 5 8 10
* | 6 9 11 12
* ]|
* Used when there is no explicit precedence of one caps over the other. e.g.
* tee's sink pad getcaps function, it will probe its src pad peers' for their
* caps and intersect them with this mode.
*
* @GST_CAPS_INTERSECT_FIRST is useful when an element wants to preserve
* another element's caps priority order when intersecting with its own caps.
* Example: If caps1 is [A, B, C] and caps2 is [E, B, D, A], the result
* would be [A, B], maintaining the first caps priority on the intersection.
*/
typedef enum {
GST_CAPS_INTERSECT_ZIG_ZAG = 0,
GST_CAPS_INTERSECT_FIRST = 1
} GstCapsIntersectMode;
/**
* GST_CAPS_ANY:
*
* Means that the element/pad can output 'anything'. Useful for elements
* that output unknown media, such as filesrc. This macro returns a singleton and
* should not be unreffed.
*/
#define GST_CAPS_ANY _gst_caps_any
/**
* GST_CAPS_NONE:
*
* The opposite of %GST_CAPS_ANY: it means that the pad/element outputs an
* undefined media type that can not be detected. This macro returns a singleton
* and should not be unreffed.
*/
#define GST_CAPS_NONE _gst_caps_none
/**
* GST_STATIC_CAPS_ANY:
*
* Creates a new #GstCaps static caps that matches anything.
* This can be used in pad templates.
*/
#define GST_STATIC_CAPS_ANY GST_STATIC_CAPS("ANY")
/**
* GST_STATIC_CAPS_NONE:
*
* Creates a new #GstCaps static caps that matches nothing.
* This can be used in pad templates.
*/
#define GST_STATIC_CAPS_NONE GST_STATIC_CAPS("NONE")
/**
* GST_CAPS_IS_SIMPLE:
* @caps: the #GstCaps instance to check
*
* Convenience macro that checks if the number of structures in the given caps
* is exactly one.
*/
#define GST_CAPS_IS_SIMPLE(caps) (gst_caps_get_size(caps) == 1)
/**
* GST_STATIC_CAPS:
* @string: the string describing the caps
*
* Creates a new #GstCaps static caps from an input string.
* This can be used in pad templates.
*/
#define GST_STATIC_CAPS(string) \
{ \
/* caps */ NULL, \
/* string */ string, \
GST_PADDING_INIT \
}
typedef struct _GstCaps GstCaps;
typedef struct _GstStaticCaps GstStaticCaps;
GST_EXPORT GstCaps * _gst_caps_any;
GST_EXPORT GstCaps * _gst_caps_none;
/**
* GST_CAPS_FLAGS:
* @caps: a #GstCaps.
*
* A flags word containing #GstCapsFlags flags set on this caps.
*/
#define GST_CAPS_FLAGS(caps) GST_MINI_OBJECT_FLAGS(caps)
/* refcount */
/**
* GST_CAPS_REFCOUNT:
* @caps: a #GstCaps
*
* Get access to the reference count field of the caps
*/
#define GST_CAPS_REFCOUNT(caps) GST_MINI_OBJECT_REFCOUNT(caps)
/**
* GST_CAPS_REFCOUNT_VALUE:
* @caps: a #GstCaps
*
* Get the reference count value of the caps.
*/
#define GST_CAPS_REFCOUNT_VALUE(caps) GST_MINI_OBJECT_REFCOUNT_VALUE(caps)
/**
* GST_CAPS_FLAG_IS_SET:
* @caps: a #GstCaps.
* @flag: the #GstCapsFlags to check.
*
* Gives the status of a specific flag on a caps.
*/
#define GST_CAPS_FLAG_IS_SET(caps,flag) GST_MINI_OBJECT_FLAG_IS_SET (caps, flag)
/**
* GST_CAPS_FLAG_SET:
* @caps: a #GstCaps.
* @flag: the #GstCapsFlags to set.
*
* Sets a caps flag on a caps.
*/
#define GST_CAPS_FLAG_SET(caps,flag) GST_MINI_OBJECT_FLAG_SET (caps, flag)
/**
* GST_CAPS_FLAG_UNSET:
* @caps: a #GstCaps.
* @flag: the #GstCapsFlags to clear.
*
* Clears a caps flag.
*/
#define GST_CAPS_FLAG_UNSET(caps,flag) GST_MINI_OBJECT_FLAG_UNSET (caps, flag)
/* refcounting */
/**
* gst_caps_ref:
* @caps: the #GstCaps to reference
*
* Add a reference to a #GstCaps object.
*
* From this point on, until the caller calls gst_caps_unref() or
* gst_caps_make_writable(), it is guaranteed that the caps object will not
* change. This means its structures won't change, etc. To use a #GstCaps
* object, you must always have a refcount on it -- either the one made
* implicitly by e.g. gst_caps_new_simple(), or via taking one explicitly with
* this function.
*
* Returns: the same #GstCaps object.
*/
#ifdef _FOOL_GTK_DOC_
G_INLINE_FUNC GstCaps * gst_caps_ref (GstCaps * caps);
#endif
static inline GstCaps *
gst_caps_ref (GstCaps * caps)
{
return (GstCaps *) gst_mini_object_ref (GST_MINI_OBJECT_CAST (caps));
}
/**
* gst_caps_unref:
* @caps: a #GstCaps.
*
* Unref a #GstCaps and and free all its structures and the
* structures' values when the refcount reaches 0.
*/
#ifdef _FOOL_GTK_DOC_
G_INLINE_FUNC void gst_caps_unref (GstCaps * caps);
#endif
static inline void
gst_caps_unref (GstCaps * caps)
{
gst_mini_object_unref (GST_MINI_OBJECT_CAST (caps));
}
/* copy caps */
/**
* gst_caps_copy:
* @caps: a #GstCaps.
*
* Creates a new #GstCaps as a copy of the old @caps. The new caps will have a
* refcount of 1, owned by the caller. The structures are copied as well.
*
* Note that this function is the semantic equivalent of a gst_caps_ref()
* followed by a gst_caps_make_writable(). If you only want to hold on to a
* reference to the data, you should use gst_caps_ref().
*
* When you are finished with the caps, call gst_caps_unref() on it.
*
* Returns: the new #GstCaps
*/
#ifdef _FOOL_GTK_DOC_
G_INLINE_FUNC GstCaps * gst_caps_copy (const GstCaps * caps);
#endif
static inline GstCaps *
gst_caps_copy (const GstCaps * caps)
{
return GST_CAPS (gst_mini_object_copy (GST_MINI_OBJECT_CAST (caps)));
}
/**
* gst_caps_is_writable:
* @caps: a #GstCaps
*
* Tests if you can safely modify @caps. It is only safe to modify caps when
* there is only one owner of the caps - ie, the object is writable.
*/
#define gst_caps_is_writable(caps) gst_mini_object_is_writable (GST_MINI_OBJECT_CAST (caps))
/**
* gst_caps_make_writable:
* @caps: (transfer full): a #GstCaps
*
* Returns a writable copy of @caps.
*
* If there is only one reference count on @caps, the caller must be the owner,
* and so this function will return the caps object unchanged. If on the other
* hand there is more than one reference on the object, a new caps object will
* be returned. The caller's reference on @caps will be removed, and instead the
* caller will own a reference to the returned object.
*
* In short, this function unrefs the caps in the argument and refs the caps
* that it returns. Don't access the argument after calling this function. See
* also: gst_caps_ref().
*
* Returns: (transfer full): a writable caps which may or may not be the
* same as @caps
*/
#define gst_caps_make_writable(caps) GST_CAPS_CAST (gst_mini_object_make_writable (GST_MINI_OBJECT_CAST (caps)))
/**
* gst_caps_replace:
* @old_caps: (inout) (transfer full) (nullable): pointer to a pointer
* to a #GstCaps to be replaced.
* @new_caps: (transfer none) (allow-none): pointer to a #GstCaps that will
* replace the caps pointed to by @old_caps.
*
* Modifies a pointer to a #GstCaps to point to a different #GstCaps. The
* modification is done atomically (so this is useful for ensuring thread safety
* in some cases), and the reference counts are updated appropriately (the old
* caps is unreffed, the new is reffed).
*
* Either @new_caps or the #GstCaps pointed to by @old_caps may be %NULL.
*
* Returns: %TRUE if @new_caps was different from @old_caps
*/
#ifdef _FOOL_GTK_DOC_
G_INLINE_FUNC gboolean gst_caps_replace (GstCaps **old_caps, GstCaps *new_caps);
#endif
static inline gboolean
gst_caps_replace (GstCaps **old_caps, GstCaps *new_caps)
{
return gst_mini_object_replace ((GstMiniObject **) old_caps, (GstMiniObject *) new_caps);
}
/**
* gst_caps_take:
* @old_caps: (inout) (transfer full): pointer to a pointer to a #GstCaps to be
* replaced.
* @new_caps: (transfer full) (allow-none): pointer to a #GstCaps that will
* replace the caps pointed to by @old_caps.
*
* Modifies a pointer to a #GstCaps to point to a different #GstCaps. This
* function is similar to gst_caps_replace() except that it takes ownership
* of @new_caps.
*
* Returns: %TRUE if @new_caps was different from @old_caps
*/
#ifdef _FOOL_GTK_DOC_
G_INLINE_FUNC gboolean gst_caps_take (GstCaps **old_caps, GstCaps *new_caps);
#endif
static inline gboolean
gst_caps_take (GstCaps **old_caps, GstCaps *new_caps)
{
return gst_mini_object_take ((GstMiniObject **) old_caps, (GstMiniObject *) new_caps);
}
/**
* GstCaps:
* @mini_object: the parent type
*
* Object describing media types.
*/
struct _GstCaps {
GstMiniObject mini_object;
};
/**
* GstStaticCaps:
* @caps: the cached #GstCaps
* @string: a string describing a caps
*
* Datastructure to initialize #GstCaps from a string description usually
* used in conjunction with GST_STATIC_CAPS() and gst_static_caps_get() to
* instantiate a #GstCaps.
*/
struct _GstStaticCaps {
/*< public >*/
GstCaps *caps;
const char *string;
/*< private >*/
gpointer _gst_reserved[GST_PADDING];
};
/**
* GstCapsForeachFunc:
* @features: the #GstCapsFeatures
* @structure: the #GstStructure
* @user_data: user data
*
* A function that will be called in gst_caps_foreach(). The function may
* not modify @features or @structure.
*
* Returns: %TRUE if the foreach operation should continue, %FALSE if
* the foreach operation should stop with %FALSE.
*
* Since: 1.6
*/
typedef gboolean (*GstCapsForeachFunc) (GstCapsFeatures *features,
GstStructure *structure,
gpointer user_data);
/**
* GstCapsMapFunc:
* @features: the #GstCapsFeatures
* @structure: the #GstStructure
* @user_data: user data
*
* A function that will be called in gst_caps_map_in_place(). The function
* may modify @features and @structure.
*
* Returns: %TRUE if the map operation should continue, %FALSE if
* the map operation should stop with %FALSE.
*/
typedef gboolean (*GstCapsMapFunc) (GstCapsFeatures *features,
GstStructure *structure,
gpointer user_data);
/**
* GstCapsFilterMapFunc:
* @features: the #GstCapsFeatures
* @structure: the #GstStructure
* @user_data: user data
*
* A function that will be called in gst_caps_filter_and_map_in_place().
* The function may modify @features and @structure, and both will be
* removed from the caps if %FALSE is returned.
*
* Returns: %TRUE if the features and structure should be preserved,
* %FALSE if it should be removed.
*/
typedef gboolean (*GstCapsFilterMapFunc) (GstCapsFeatures *features,
GstStructure *structure,
gpointer user_data);
GType gst_caps_get_type (void);
GstCaps * gst_caps_new_empty (void);
GstCaps * gst_caps_new_any (void);
GstCaps * gst_caps_new_empty_simple (const char *media_type) G_GNUC_WARN_UNUSED_RESULT;
GstCaps * gst_caps_new_simple (const char *media_type,
const char *fieldname,
...) G_GNUC_NULL_TERMINATED G_GNUC_WARN_UNUSED_RESULT;
GstCaps * gst_caps_new_full (GstStructure *struct1,
...) G_GNUC_NULL_TERMINATED G_GNUC_WARN_UNUSED_RESULT;
GstCaps * gst_caps_new_full_valist (GstStructure *structure,
va_list var_args) G_GNUC_WARN_UNUSED_RESULT;
GType gst_static_caps_get_type (void);
GstCaps * gst_static_caps_get (GstStaticCaps *static_caps);
void gst_static_caps_cleanup (GstStaticCaps *static_caps);
/* manipulation */
void gst_caps_append (GstCaps *caps1,
GstCaps *caps2);
void gst_caps_append_structure (GstCaps *caps,
GstStructure *structure);
void gst_caps_append_structure_full (GstCaps *caps,
GstStructure *structure,
GstCapsFeatures *features);
void gst_caps_remove_structure (GstCaps *caps, guint idx);
GstCaps * gst_caps_merge (GstCaps *caps1,
GstCaps *caps2) G_GNUC_WARN_UNUSED_RESULT;
GstCaps * gst_caps_merge_structure (GstCaps *caps,
GstStructure *structure) G_GNUC_WARN_UNUSED_RESULT;
GstCaps * gst_caps_merge_structure_full (GstCaps *caps,
GstStructure *structure,
GstCapsFeatures *features) G_GNUC_WARN_UNUSED_RESULT;
guint gst_caps_get_size (const GstCaps *caps);
GstStructure * gst_caps_get_structure (const GstCaps *caps,
guint index);
GstStructure * gst_caps_steal_structure (GstCaps *caps,
guint index) G_GNUC_WARN_UNUSED_RESULT;
void gst_caps_set_features (GstCaps *caps,
guint index,
GstCapsFeatures * features);
GstCapsFeatures * gst_caps_get_features (const GstCaps *caps,
guint index);
GstCaps * gst_caps_copy_nth (const GstCaps *caps, guint nth) G_GNUC_WARN_UNUSED_RESULT;
GstCaps * gst_caps_truncate (GstCaps *caps) G_GNUC_WARN_UNUSED_RESULT;
void gst_caps_set_value (GstCaps *caps,
const char *field,
const GValue *value);
void gst_caps_set_simple (GstCaps *caps,
const char *field, ...) G_GNUC_NULL_TERMINATED;
void gst_caps_set_simple_valist (GstCaps *caps,
const char *field,
va_list varargs);
gboolean gst_caps_foreach (const GstCaps *caps,
GstCapsForeachFunc func,
gpointer user_data);
gboolean gst_caps_map_in_place (GstCaps *caps,
GstCapsMapFunc func,
gpointer user_data);
void gst_caps_filter_and_map_in_place (GstCaps *caps,
GstCapsFilterMapFunc func,
gpointer user_data);
/* tests */
gboolean gst_caps_is_any (const GstCaps *caps);
gboolean gst_caps_is_empty (const GstCaps *caps);
gboolean gst_caps_is_fixed (const GstCaps *caps);
gboolean gst_caps_is_always_compatible (const GstCaps *caps1,
const GstCaps *caps2);
gboolean gst_caps_is_subset (const GstCaps *subset,
const GstCaps *superset);
gboolean gst_caps_is_subset_structure (const GstCaps *caps,
const GstStructure *structure);
gboolean gst_caps_is_subset_structure_full (const GstCaps *caps,
const GstStructure *structure,
const GstCapsFeatures *features);
gboolean gst_caps_is_equal (const GstCaps *caps1,
const GstCaps *caps2);
gboolean gst_caps_is_equal_fixed (const GstCaps *caps1,
const GstCaps *caps2);
gboolean gst_caps_can_intersect (const GstCaps * caps1,
const GstCaps * caps2);
gboolean gst_caps_is_strictly_equal (const GstCaps *caps1,
const GstCaps *caps2);
/* operations */
GstCaps * gst_caps_intersect (GstCaps *caps1,
GstCaps *caps2) G_GNUC_WARN_UNUSED_RESULT;
GstCaps * gst_caps_intersect_full (GstCaps *caps1,
GstCaps *caps2,
GstCapsIntersectMode mode) G_GNUC_WARN_UNUSED_RESULT;
GstCaps * gst_caps_subtract (GstCaps *minuend,
GstCaps *subtrahend) G_GNUC_WARN_UNUSED_RESULT;
GstCaps * gst_caps_normalize (GstCaps *caps) G_GNUC_WARN_UNUSED_RESULT;
GstCaps * gst_caps_simplify (GstCaps *caps) G_GNUC_WARN_UNUSED_RESULT;
GstCaps * gst_caps_fixate (GstCaps *caps) G_GNUC_WARN_UNUSED_RESULT;
/* utility */
gchar * gst_caps_to_string (const GstCaps *caps) G_GNUC_MALLOC;
GstCaps * gst_caps_from_string (const gchar *string) G_GNUC_WARN_UNUSED_RESULT;
G_END_DECLS
#endif /* __GST_CAPS_H__ */
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