|  |  |  | GStreamer 0.8 Core API Reference (0.8.4) |  | 
|---|
GstIndex — Generate indexes on objects
struct GstIndex; #define GST_TYPE_INDEX_ENTRY struct GstIndexEntry; struct GstIndexGroup; enum GstIndexCertainty; enum GstIndexEntryType; enum GstIndexLookupMethod; #define GST_INDEX_NASSOCS (entry) #define GST_INDEX_ASSOC_FLAGS (entry) #define GST_INDEX_ASSOC_FORMAT (entry,i) #define GST_INDEX_ASSOC_VALUE (entry,i) struct GstIndexAssociation; enum GstAssocFlags; #define GST_INDEX_FORMAT_FORMAT (entry) #define GST_INDEX_FORMAT_KEY (entry) #define GST_INDEX_ID_INVALID #define GST_INDEX_ID_DESCRIPTION (entry) gboolean (*GstIndexFilter) (GstIndex *index, GstIndexEntry *entry); enum GstIndexResolverMethod; gboolean (*GstIndexResolver) (GstIndex *index, GstObject *writer, gchar **writer_string, gpointer user_data); enum GstIndexFlags; #define GST_INDEX_IS_READABLE (obj) #define GST_INDEX_IS_WRITABLE (obj) GstIndex* gst_index_new (void); void gst_index_commit (GstIndex *index, gint id); gint gst_index_get_group (GstIndex *index); gint gst_index_new_group (GstIndex *index); gboolean gst_index_set_group (GstIndex *index, gint groupnum); void gst_index_set_certainty (GstIndex *index, GstIndexCertainty certainty); GstIndexCertainty gst_index_get_certainty (GstIndex *index); void gst_index_set_filter (GstIndex *index, GstIndexFilter filter, gpointer user_data); void gst_index_set_resolver (GstIndex *index, GstIndexResolver resolver, gpointer user_data); gboolean gst_index_get_writer_id (GstIndex *index, GstObject *writer, gint *id); GstIndexEntry* gst_index_add_format (GstIndex *index, gint id, GstFormat format); GstIndexEntry* gst_index_add_association (GstIndex *index, gint id, GstAssocFlags flags, GstFormat format, gint64 value, ...); GstIndexEntry* gst_index_add_object (GstIndex *index, gint id, gchar *key, GType type, gpointer object); GstIndexEntry* gst_index_add_id (GstIndex *index, gint id, gchar *description); GstIndexEntry* gst_index_get_assoc_entry (GstIndex *index, gint id, GstIndexLookupMethod method, GstAssocFlags flags, GstFormat format, gint64 value); GstIndexEntry* gst_index_get_assoc_entry_full (GstIndex *index, gint id, GstIndexLookupMethod method, GstAssocFlags flags, GstFormat format, gint64 value, GCompareDataFunc func, gpointer user_data); GType gst_index_entry_get_type (void); GstIndexEntry* gst_index_entry_copy (GstIndexEntry *entry); void gst_index_entry_free (GstIndexEntry *entry); gboolean gst_index_entry_assoc_map (GstIndexEntry *entry, GstFormat format, gint64 *value); #define GST_TYPE_INDEX_FACTORY #define GST_INDEX_FACTORY (obj) #define GST_IS_INDEX_FACTORY (obj) #define GST_INDEX_FACTORY_CLASS (klass) #define GST_IS_INDEX_FACTORY_CLASS (klass) #define GST_INDEX_FACTORY_GET_CLASS (obj) struct GstIndexFactory; struct GstIndexFactoryClass; GType gst_index_factory_get_type (void); GstIndexFactory* gst_index_factory_new (const gchar *name, const gchar *longdesc, GType type); void gst_index_factory_destroy (GstIndexFactory *factory); GstIndexFactory* gst_index_factory_find (const gchar *name); GstIndex* gst_index_factory_create (GstIndexFactory *factory); GstIndex* gst_index_factory_make (const gchar *name);
GObject +----GstObject +----GstIndex +----GstMemIndex +----GstFileIndex
GObject +----GstPluginFeature +----GstIndexFactory
"entry-added" void user_function (GstIndex *gstindex, GstIndexEntry *arg1, gpointer user_data);
struct GstIndexEntry {
  GstIndexEntryType	 type;
  gint			 id;
  union {
    struct {
      gchar		*description;
    } id;
    struct {
      gint		 nassocs;
      GstIndexAssociation 
	      		*assocs;
      GstAssocFlags	 flags;
    } assoc;
    struct {
      gchar		*key;
      GType		 type;
      gpointer		 object;
    } object;
    struct {
      GstFormat		 format;
      gchar		*key;
    } format;
  } data;
};
The basic element of an index.
struct GstIndexGroup {
  /* unique ID of group in index */
  gint groupnum;
  /* list of entries */
  GList *entries;
  /* the certainty level of the group */
  GstIndexCertainty certainty;
  /* peer group that contains more certain entries */
  gint peergroup;
};
A group of related entries in an index.
typedef enum {
  GST_INDEX_UNKNOWN,
  GST_INDEX_CERTAIN,
  GST_INDEX_FUZZY
} GstIndexCertainty;
The certainty of a group in the index.
| GST_INDEX_UNKNOWN | accuracy is not known | 
| GST_INDEX_CERTAIN | accuracy is perfect | 
| GST_INDEX_FUZZY | accuracy is fuzzy | 
typedef enum {
  GST_INDEX_ENTRY_ID,
  GST_INDEX_ENTRY_ASSOCIATION,
  GST_INDEX_ENTRY_OBJECT,
  GST_INDEX_ENTRY_FORMAT
} GstIndexEntryType;
The different types of entries in the index.
| GST_INDEX_ENTRY_ID | This entry is an id that maps an index id to its owner object | 
| GST_INDEX_ENTRY_ASSOCIATION | This entry is an association between formats | 
| GST_INDEX_ENTRY_OBJECT | An object | 
| GST_INDEX_ENTRY_FORMAT | A format definition | 
typedef enum {
  GST_INDEX_LOOKUP_EXACT,
  GST_INDEX_LOOKUP_BEFORE,
  GST_INDEX_LOOKUP_AFTER
} GstIndexLookupMethod;
Specify the method to find an index entry in the index.
| GST_INDEX_LOOKUP_EXACT | There has to be an exact indexentry with the given format/value | 
| GST_INDEX_LOOKUP_BEFORE | The exact entry or the one before it | 
| GST_INDEX_LOOKUP_AFTER | The exact entry or the one after it | 
#define GST_INDEX_NASSOCS(entry) ((entry)->data.assoc.nassocs)
Get the number of associations in the entry.
| entry : | The entry to query | 
#define GST_INDEX_ASSOC_FLAGS(entry) ((entry)->data.assoc.flags)
Get the flags for this entry
| entry : | The entry to query | 
#define GST_INDEX_ASSOC_FORMAT(entry,i) ((entry)->data.assoc.assocs[(i)].format)
Get the i-th format of the entry.
| entry : | The entry to query | 
| i : | The format index | 
#define GST_INDEX_ASSOC_VALUE(entry,i) ((entry)->data.assoc.assocs[(i)].value)
Get the i-th value of the entry.
| entry : | The entry to query | 
| i : | The value index | 
struct GstIndexAssociation {
  GstFormat 	format;
  gint64 	value;
};
An association in an entry.
| GstFormat format | the format of the association | 
| gint64 value | the value of the association | 
typedef enum {
  GST_ASSOCIATION_FLAG_NONE 	= 0,
  GST_ASSOCIATION_FLAG_KEY_UNIT = (1 << 0),
  /* new flags should start here */
  GST_ASSOCIATION_FLAG_LAST	= (1 << 8)
} GstAssocFlags;
flags for an association entry
| GST_ASSOCIATION_FLAG_NONE | no extra flags | 
| GST_ASSOCIATION_FLAG_KEY_UNIT | the entry marks a key unit, a key unit is one that marks a place where one can randomly seek to. | 
| GST_ASSOCIATION_FLAG_LAST | extra user defined flags should start here. | 
#define GST_INDEX_FORMAT_FORMAT(entry) ((entry)->data.format.format)
Get the format of the format entry
| entry : | The entry to query | 
#define GST_INDEX_FORMAT_KEY(entry) ((entry)->data.format.key)
Get the key of the format entry
| entry : | The entry to query | 
#define GST_INDEX_ID_DESCRIPTION(entry) ((entry)->data.id.description)
Get the description of the id entry
| entry : | The entry to query | 
gboolean (*GstIndexFilter) (GstIndex *index, GstIndexEntry *entry);
Function to filter out entries in the index.
| index : | The index being queried | 
| entry : | The entry to be added. | 
| Returns : | This function should return TRUE if the entry is to be added to the index, FALSE otherwise. | 
typedef enum {
  GST_INDEX_RESOLVER_CUSTOM,
  GST_INDEX_RESOLVER_GTYPE,
  GST_INDEX_RESOLVER_PATH
} GstIndexResolverMethod;
The method used to resolve index writers
| GST_INDEX_RESOLVER_CUSTOM | Use a custom resolver | 
| GST_INDEX_RESOLVER_GTYPE | Resolve based on the GType of the object | 
| GST_INDEX_RESOLVER_PATH | Resolve on the path in graph | 
gboolean (*GstIndexResolver) (GstIndex *index, GstObject *writer, gchar **writer_string, gpointer user_data);
Function to resolve ids to writer descriptions.
| index : | the index being queried. | 
| writer : | The object that wants to write | 
| writer_string : | A description of the writer. | 
| user_data : | user_data as registered | 
| Returns : | TRUE if an id could be assigned to the writer. | 
typedef enum {
  GST_INDEX_WRITABLE 		= GST_OBJECT_FLAG_LAST,	
  GST_INDEX_READABLE,	
  GST_INDEX_FLAG_LAST 		= GST_OBJECT_FLAG_LAST + 8
} GstIndexFlags;
Flags for this index
| GST_INDEX_WRITABLE | The index is writable | 
| GST_INDEX_READABLE | The index is readable | 
| GST_INDEX_FLAG_LAST | First flag that can be used by subclasses | 
#define GST_INDEX_IS_READABLE(obj) (GST_FLAG_IS_SET (obj, GST_INDEX_READABLE))
Check if the index can be read from
| obj : | The index to check | 
#define GST_INDEX_IS_WRITABLE(obj) (GST_FLAG_IS_SET (obj, GST_INDEX_WRITABLE))
Check if the index can be written to
| obj : | The index to check | 
GstIndex* gst_index_new (void);
Create a new tileindex object
| Returns : | a new index object | 
void gst_index_commit (GstIndex *index, gint id);
Tell the index that the writer with the given id is done with this index and is not going to write any more entries to it.
| index : | the index to commit | 
| id : | the writer that commited the index | 
gint gst_index_get_group (GstIndex *index);
Get the id of the current group.
| index : | the index to get the current group from | 
| Returns : | the id of the current group. | 
gint gst_index_new_group (GstIndex *index);
Create a new group for the given index. It will be set as the current group.
| index : | the index to create the new group in | 
| Returns : | the id of the newly created group. | 
gboolean gst_index_set_group (GstIndex *index, gint groupnum);
Set the current groupnumber to the given argument.
| index : | the index to set the new group in | 
| groupnum : | the groupnumber to set | 
| Returns : | TRUE if the operation succeeded, FALSE if the group did not exist. | 
void gst_index_set_certainty (GstIndex *index, GstIndexCertainty certainty);
Set the certainty of the given index.
| index : | the index to set the certainty on | 
| certainty : | the certainty to set | 
GstIndexCertainty gst_index_get_certainty (GstIndex *index);
Get the certainty of the given index.
| index : | the index to get the certainty of | 
| Returns : | the certainty of the index. | 
void gst_index_set_filter (GstIndex *index, GstIndexFilter filter, gpointer user_data);
Lets the app register a custom filter function so that it can select what entries should be stored in the index.
| index : | the index to register the filter on | 
| filter : | the filter to register | 
| user_data : | data passed to the filter function | 
void gst_index_set_resolver (GstIndex *index, GstIndexResolver resolver, gpointer user_data);
Lets the app register a custom function to map index ids to writer descriptions.
| index : | the index to register the resolver on | 
| resolver : | the resolver to register | 
| user_data : | data passed to the resolver function | 
gboolean gst_index_get_writer_id (GstIndex *index, GstObject *writer, gint *id);
Before entries can be added to the index, a writer should obtain a unique id. The methods to add new entries to the index require this id as an argument.
The application can implement a custom function to map the writer object to a string. That string will be used to register or look up an id in the index.
| index : | the index to get a unique write id for | 
| writer : | the GstObject to allocate an id for | 
| id : | a pointer to a gint to hold the id | 
| Returns : | TRUE if the writer would be mapped to an id. | 
GstIndexEntry* gst_index_add_format (GstIndex *index, gint id, GstFormat format);
Adds a format entry into the index. This function is used to map dynamic GstFormat ids to their original format key.
| index : | the index to add the entry to | 
| id : | the id of the index writer | 
| format : | the format to add to the index | 
| Returns : | a pointer to the newly added entry in the index. | 
GstIndexEntry* gst_index_add_association (GstIndex *index, gint id, GstAssocFlags flags, GstFormat format, gint64 value, ...);
Associate given format/value pairs with each other. Be sure to pass gint64 values to this functions varargs, you might want to use a gint64 cast to be sure.
| index : | the index to add the entry to | 
| id : | the id of the index writer | 
| flags : | optinal flags for this entry | 
| format : | the format of the value | 
| value : | the value | 
| ... : | other format/value pairs or 0 to end the list | 
| Returns : | a pointer to the newly added entry in the index. | 
GstIndexEntry* gst_index_add_object (GstIndex *index, gint id, gchar *key, GType type, gpointer object);
Add the given object to the index with the given key.
| index : | the index to add the object to | 
| id : | the id of the index writer | 
| key : | a key for the object | 
| type : | the GType of the object | 
| object : | a pointer to the object to add | 
| Returns : | a pointer to the newly added entry in the index. | 
GstIndexEntry* gst_index_add_id (GstIndex *index, gint id, gchar *description);
Add an id entry into the index.
| index : | the index to add the entry to | 
| id : | the id of the index writer | 
| description : | the description of the index writer | 
| Returns : | a pointer to the newly added entry in the index. | 
GstIndexEntry* gst_index_get_assoc_entry (GstIndex *index, gint id, GstIndexLookupMethod method, GstAssocFlags flags, GstFormat format, gint64 value);
Finds the given format/value in the index
| index : | the index to search | 
| id : | the id of the index writer | 
| method : | The lookup method to use | 
| flags : | Flags for the entry | 
| format : | the format of the value | 
| value : | the value to find | 
| Returns : | the entry associated with the value or NULL if the value was not found. | 
GstIndexEntry* gst_index_get_assoc_entry_full (GstIndex *index, gint id, GstIndexLookupMethod method, GstAssocFlags flags, GstFormat format, gint64 value, GCompareDataFunc func, gpointer user_data);
Finds the given format/value in the index with the given compare function and user_data.
| index : | the index to search | 
| id : | the id of the index writer | 
| method : | The lookup method to use | 
| flags : | Flags for the entry | 
| format : | the format of the value | 
| value : | the value to find | 
| func : | the function used to compare entries | 
| user_data : | user data passed to the compare function | 
| Returns : | the entry associated with the value or NULL if the value was not found. | 
GstIndexEntry* gst_index_entry_copy (GstIndexEntry *entry);
Copies an entry and returns the result.
| entry : | the entry to copy | 
| Returns : | a newly allocated GstIndexEntry. | 
void gst_index_entry_free (GstIndexEntry *entry);
Free the memory used by the given entry.
| entry : | the entry to free | 
gboolean gst_index_entry_assoc_map (GstIndexEntry *entry, GstFormat format, gint64 *value);
Gets alternative formats associated with the indexentry.
| entry : | the index to search | 
| format : | the format of the value the find | 
| value : | a pointer to store the value | 
| Returns : | TRUE if there was a value associated with the given format. | 
#define GST_INDEX_FACTORY(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_INDEX_FACTORY, GstIndexFactory))
| obj : | 
#define GST_IS_INDEX_FACTORY(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_INDEX_FACTORY))
| obj : | 
#define GST_INDEX_FACTORY_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_INDEX_FACTORY, GstIndexFactoryClass))
| klass : | 
#define GST_IS_INDEX_FACTORY_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_INDEX_FACTORY))
| klass : | 
#define GST_INDEX_FACTORY_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_INDEX_FACTORY, GstIndexFactoryClass))
| obj : | 
struct GstIndexFactoryClass {
  GstPluginFeatureClass parent; 
  gpointer _gst_reserved[GST_PADDING];
};
GstIndexFactory* gst_index_factory_new (const gchar *name, const gchar *longdesc, GType type);
Create a new indexfactory with the given parameters
| name : | name of indexfactory to create | 
| longdesc : | long description of indexfactory to create | 
| type : | the GType of the GstIndex element of this factory | 
| Returns : | a new GstIndexFactory. | 
void gst_index_factory_destroy (GstIndexFactory *factory);
Removes the index from the global list.
| factory : | factory to destroy | 
GstIndexFactory* gst_index_factory_find (const gchar *name);
Search for an indexfactory of the given name.
| name : | name of indexfactory to find | 
| Returns : | GstIndexFactory if found, NULL otherwise | 
GstIndex* gst_index_factory_create (GstIndexFactory *factory);
Create a new GstIndex instance from the given indexfactory.
| factory : | the factory used to create the instance | 
| Returns : | A new GstIndex instance. | 
void user_function (GstIndex *gstindex, GstIndexEntry *arg1, gpointer user_data);
Is emited when a new entry is added to the index.
| gstindex : | the object which received the signal. | 
| arg1 : | The entry added to the index. | 
| user_data : | user data set when the signal handler was connected. | 
| << GstFormat | GstInfo >> |