GST_META_FLAGS()

#define GST_META_FLAGS(meta)  (GST_META_CAST (meta)->flags)

A flags word containing GstMetaFlags flags set on meta

GST_META_FLAG_IS_SET()

#define GST_META_FLAG_IS_SET(meta,flag)        !!(GST_META_FLAGS (meta) & (flag))

Gives the status of a specific flag on a metadata.

GST_META_FLAG_SET()

#define GST_META_FLAG_SET(meta,flag)           (GST_META_FLAGS (meta) |= (flag))

Sets a metadata flag on a metadata.

GST_META_FLAG_UNSET()

#define GST_META_FLAG_UNSET(meta,flag)         (GST_META_FLAGS (meta) &= ~(flag))

Clears a metadata flag.

GstMetaInitFunction ()

gboolean
(*GstMetaInitFunction) (GstMeta *meta,
                        gpointer params,
                        GstBuffer *buffer);

Function called when meta is initialized in buffer .

GstMetaFreeFunction ()

void
(*GstMetaFreeFunction) (GstMeta *meta,
                        GstBuffer *buffer);

Function called when meta is freed in buffer .

GstMetaTransformFunction ()

gboolean
(*GstMetaTransformFunction) (GstBuffer *transbuf,
                             GstMeta *meta,
                             GstBuffer *buffer,
                             GQuark type,
                             gpointer data);

Function called for each meta in buffer as a result of performing a transformation on transbuf . Additional type specific transform data is passed to the function as data .

Implementations should check the type of the transform and parse additional type specific fields in data that should be used to update the metadata on transbuf .

GST_META_TRANSFORM_IS_COPY()

#define GST_META_TRANSFORM_IS_COPY(type) ((type) == _gst_meta_transform_copy)

Check if the transform type is a copy transform

gst_meta_api_type_register ()

GType
gst_meta_api_type_register (const gchar *api,
                            const gchar **tags);

Register and return a GType for the api and associate it with tags .

gst_meta_api_type_has_tag ()

gboolean
gst_meta_api_type_has_tag (GType api,
                           GQuark tag);

Check if api was registered with tag .

gst_meta_api_type_get_tags ()

const gchar * const*
gst_meta_api_type_get_tags (GType api);

Since: 1.2

gst_meta_register ()

const GstMetaInfo *
gst_meta_register (GType api,
                   const gchar *impl,
                   gsize size,
                   GstMetaInitFunction init_func,
                   GstMetaFreeFunction free_func,
                   GstMetaTransformFunction transform_func);

Register a new GstMeta implementation.

The same info can be retrieved later with gst_meta_get_info() by using impl as the key.

gst_meta_get_info ()

const GstMetaInfo *
gst_meta_get_info (const gchar *impl);

Lookup a previously registered meta info structure by its implementation name impl .

struct GstMeta

struct GstMeta {
  GstMetaFlags       flags;
  const GstMetaInfo *info;
};

Base structure for metadata. Custom metadata will put this structure as the first member of their structure.

enum GstMetaFlags

Extra metadata flags.

struct GstMetaInfo

struct GstMetaInfo {
  GType                      api;
  GType                      type;
  gsize                      size;

  GstMetaInitFunction        init_func;
  GstMetaFreeFunction        free_func;
  GstMetaTransformFunction   transform_func;

  /* No padding needed, GstMetaInfo is always allocated by GStreamer and is
   * not subclassable or stack-allocatable, so we can extend it as we please
   * just like interfaces */
};

The GstMetaInfo provides information about a specific metadata structure.

GstMetaTransformCopy

typedef struct {
  gboolean region;
  gsize offset;
  gsize size;
} GstMetaTransformCopy;

Extra data passed to a "gst-copy" transform GstMetaTransformFunction.

GST_META_TAG_MEMORY

#define GST_META_TAG_MEMORY (_gst_meta_tag_memory)

Metadata tagged with this tag depends on the particular memory or buffer that it is on.

GST_META_TAG_MEMORY_STR

#define GST_META_TAG_MEMORY_STR "memory"

This metadata stays relevant as long as memory layout is unchanged.

Since: 1.2