1 /* GStreamer
2  * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3  *                    2000 Wim Taymans <wim.taymans@chello.be>
4  *
5  * gstindex.h: Header for GstIndex, base class to handle efficient
6  *             storage or caching of seeking information.
7  *
8  * This library is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Library General Public
10  * License as published by the Free Software Foundation; either
11  * version 2 of the License, or (at your option) any later version.
12  *
13  * This library is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * Library General Public License for more details.
17  *
18  * You should have received a copy of the GNU Library General Public
19  * License along with this library; if not, write to the
20  * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
21  * Boston, MA 02110-1301, USA.
22  */
23 
24 #ifndef __GST_INDEX_H__
25 #define __GST_INDEX_H__
26 
27 #include <gst/gstobject.h>
28 #include <gst/gstformat.h>
29 #include <gst/gstpluginfeature.h>
30 
31 G_BEGIN_DECLS
32 
33 #define GST_TYPE_INDEX                  (gst_index_get_type ())
34 #define GST_INDEX(obj)                  (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_INDEX, GstIndex))
35 #define GST_IS_INDEX(obj)               (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_INDEX))
36 #define GST_INDEX_CLASS(klass)          (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_INDEX, GstIndexClass))
37 #define GST_IS_INDEX_CLASS(klass)       (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_INDEX))
38 #define GST_INDEX_GET_CLASS(obj)        (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_INDEX, GstIndexClass))
39 
40 #define GST_TYPE_INDEX_ENTRY            (gst_index_entry_get_type())
41 
42 typedef struct _GstIndexEntry GstIndexEntry;
43 typedef struct _GstIndexGroup GstIndexGroup;
44 typedef struct _GstIndex GstIndex;
45 typedef struct _GstIndexClass GstIndexClass;
46 
47 /**
48  * GstIndexCertainty:
49  * @GST_INDEX_UNKNOWN: accuracy is not known
50  * @GST_INDEX_CERTAIN: accuracy is perfect
51  * @GST_INDEX_FUZZY: accuracy is fuzzy
52  *
53  * The certainty of a group in the index.
54  */
55 typedef enum {
56   GST_INDEX_UNKNOWN,
57   GST_INDEX_CERTAIN,
58   GST_INDEX_FUZZY
59 } GstIndexCertainty;
60 
61 /**
62  * GstIndexEntryType:
63  * @GST_INDEX_ENTRY_ID: This entry is an id that maps an index id to its owner object
64  * @GST_INDEX_ENTRY_ASSOCIATION: This entry is an association between formats
65  * @GST_INDEX_ENTRY_OBJECT: An object
66  * @GST_INDEX_ENTRY_FORMAT: A format definition
67  *
68  * The different types of entries in the index.
69  */
70 typedef enum {
71   GST_INDEX_ENTRY_ID,
72   GST_INDEX_ENTRY_ASSOCIATION,
73   GST_INDEX_ENTRY_OBJECT,
74   GST_INDEX_ENTRY_FORMAT
75 } GstIndexEntryType;
76 
77 /**
78  * GstIndexLookupMethod:
79  * @GST_INDEX_LOOKUP_EXACT: There has to be an exact indexentry with the given format/value
80  * @GST_INDEX_LOOKUP_BEFORE: The exact entry or the one before it
81  * @GST_INDEX_LOOKUP_AFTER: The exact entry or the one after it
82  *
83  * Specify the method to find an index entry in the index.
84  */
85 typedef enum {
86   GST_INDEX_LOOKUP_EXACT,
87   GST_INDEX_LOOKUP_BEFORE,
88   GST_INDEX_LOOKUP_AFTER
89 } GstIndexLookupMethod;
90 
91 /**
92  * GST_INDEX_NASSOCS:
93  * @entry: The entry to query
94  *
95  * Get the number of associations in the entry.
96  */
97 #define GST_INDEX_NASSOCS(entry)                ((entry)->data.assoc.nassocs)
98 
99 /**
100  * GST_INDEX_ASSOC_FLAGS:
101  * @entry: The entry to query
102  *
103  *  Get the flags for this entry.
104  */
105 #define GST_INDEX_ASSOC_FLAGS(entry)            ((entry)->data.assoc.flags)
106 
107 /**
108  * GST_INDEX_ASSOC_FORMAT:
109  * @entry: The entry to query
110  * @i: The format index
111  *
112  * Get the i-th format of the entry.
113  */
114 #define GST_INDEX_ASSOC_FORMAT(entry,i)         ((entry)->data.assoc.assocs[(i)].format)
115 
116 /**
117  * GST_INDEX_ASSOC_VALUE:
118  * @entry: The entry to query
119  * @i: The value index
120  *
121  * Get the i-th value of the entry.
122  */
123 #define GST_INDEX_ASSOC_VALUE(entry,i)          ((entry)->data.assoc.assocs[(i)].value)
124 
125 typedef struct _GstIndexAssociation GstIndexAssociation;
126 
127 /**
128  * GstIndexAssociation:
129  * @format: the format of the association
130  * @value: the value of the association
131  *
132  * An association in an entry.
133  */
134 struct _GstIndexAssociation {
135   GstFormat     format;
136   gint64        value;
137 };
138 
139 /**
140  * GstIndexAssociationFlags:
141  * @GST_INDEX_ASSOCIATION_FLAG_NONE: no extra flags
142  * @GST_INDEX_ASSOCIATION_FLAG_KEY_UNIT: the entry marks a key unit, a key unit is one
143  *  that marks a place where one can randomly seek to.
144  * @GST_INDEX_ASSOCIATION_FLAG_DELTA_UNIT: the entry marks a delta unit, a delta unit
145  *  is one that marks a place where one can relatively seek to.
146  * @GST_INDEX_ASSOCIATION_FLAG_LAST: extra user defined flags should start here.
147  *
148  * Flags for an association entry.
149  */
150 typedef enum {
151   GST_INDEX_ASSOCIATION_FLAG_NONE       = 0,
152   GST_INDEX_ASSOCIATION_FLAG_KEY_UNIT   = (1 << 0),
153   GST_INDEX_ASSOCIATION_FLAG_DELTA_UNIT = (1 << 1),
154 
155   /* new flags should start here */
156   GST_INDEX_ASSOCIATION_FLAG_LAST     = (1 << 8)
157 } GstIndexAssociationFlags;
158 
159 /**
160  * GST_INDEX_FORMAT_FORMAT:
161  * @entry: The entry to query
162  *
163  * Get the format of the format entry
164  */
165 #define GST_INDEX_FORMAT_FORMAT(entry)          ((entry)->data.format.format)
166 
167 /**
168  * GST_INDEX_FORMAT_KEY:
169  * @entry: The entry to query
170  *
171  * Get the key of the format entry
172  */
173 #define GST_INDEX_FORMAT_KEY(entry)             ((entry)->data.format.key)
174 
175 /**
176  * GST_INDEX_ID_INVALID:
177  *
178  * Constant for an invalid index id
179  */
180 #define GST_INDEX_ID_INVALID                    (-1)
181 
182 /**
183  * GST_INDEX_ID_DESCRIPTION:
184  * @entry: The entry to query
185  *
186  * Get the description of the id entry
187  */
188 #define GST_INDEX_ID_DESCRIPTION(entry)         ((entry)->data.id.description)
189 
190 /**
191  * GstIndexEntry:
192  *
193  * The basic element of an index.
194  */
195 struct _GstIndexEntry {
196   /*< private >*/
197   GstIndexEntryType      type;
198   gint                   id;
199 
200   union {
201     struct {
202       gchar             *description;
203     } id;
204     struct {
205       gint               nassocs;
206       GstIndexAssociation
207                         *assocs;
208       GstIndexAssociationFlags      flags;
209     } assoc;
210     struct {
211       gchar             *key;
212       GType              type;
213       gpointer           object;
214     } object;
215     struct {
216       GstFormat          format;
217       const gchar       *key;
218     } format;
219   } data;
220 };
221 
222 /**
223  * GstIndexGroup:
224  *
225  * A group of related entries in an index.
226  */
227 
228 struct _GstIndexGroup {
229   /*< private >*/
230   /* unique ID of group in index */
231   gint groupnum;
232 
233   /* list of entries */
234   GList *entries;
235 
236   /* the certainty level of the group */
237   GstIndexCertainty certainty;
238 
239   /* peer group that contains more certain entries */
240   gint peergroup;
241 };
242 
243 /**
244  * GstIndexFilter:
245  * @index: The index being queried
246  * @entry: The entry to be added.
247  * @user_data: User data passed to the function.
248  *
249  * Function to filter out entries in the index.
250  *
251  * Returns: This function should return %TRUE if the entry is to be added
252  * to the index, %FALSE otherwise.
253  *
254  */
255 typedef gboolean        (*GstIndexFilter)               (GstIndex *index,
256                                                          GstIndexEntry *entry,
257                                                          gpointer user_data);
258 /**
259  * GstIndexResolverMethod:
260  * @GST_INDEX_RESOLVER_CUSTOM: Use a custom resolver
261  * @GST_INDEX_RESOLVER_GTYPE: Resolve based on the GType of the object
262  * @GST_INDEX_RESOLVER_PATH: Resolve on the path in graph
263  *
264  * The method used to resolve index writers
265  */
266 typedef enum {
267   GST_INDEX_RESOLVER_CUSTOM,
268   GST_INDEX_RESOLVER_GTYPE,
269   GST_INDEX_RESOLVER_PATH
270 } GstIndexResolverMethod;
271 
272 /**
273  * GstIndexResolver:
274  * @index: the index being queried.
275  * @writer: The object that wants to write
276  * @writer_string: A description of the writer.
277  * @user_data: user_data as registered
278  *
279  * Function to resolve ids to writer descriptions.
280  *
281  * Returns: %TRUE if an id could be assigned to the writer.
282  */
283 typedef gboolean        (*GstIndexResolver)             (GstIndex *index,
284                                                          GstObject *writer,
285                                                          gchar **writer_string,
286                                                          gpointer user_data);
287 
288 /**
289  * GstIndexFlags:
290  * @GST_INDEX_WRITABLE: The index is writable
291  * @GST_INDEX_READABLE: The index is readable
292  * @GST_INDEX_FLAG_LAST: First flag that can be used by subclasses
293  *
294  * Flags for this index
295  */
296 typedef enum {
297   GST_INDEX_WRITABLE    = (GST_OBJECT_FLAG_LAST << 0),
298   GST_INDEX_READABLE    = (GST_OBJECT_FLAG_LAST << 1),
299 
300   GST_INDEX_FLAG_LAST   = (GST_OBJECT_FLAG_LAST << 8)
301 } GstIndexFlags;
302 
303 /**
304  * GST_INDEX_IS_READABLE:
305  * @obj: The index to check
306  *
307  * Check if the index can be read from
308  */
309 #define GST_INDEX_IS_READABLE(obj)    (GST_OBJECT_FLAG_IS_SET (obj, GST_INDEX_READABLE))
310 
311 /**
312  * GST_INDEX_IS_WRITABLE:
313  * @obj: The index to check
314  *
315  * Check if the index can be written to
316  */
317 #define GST_INDEX_IS_WRITABLE(obj)    (GST_OBJECT_FLAG_IS_SET (obj, GST_INDEX_WRITABLE))
318 
319 /**
320  * GstIndex:
321  *
322  * Opaque #GstIndex structure.
323  */
324 struct _GstIndex {
325   GstObject              object;
326 
327   /*< private >*/
328   GList                 *groups;
329   GstIndexGroup         *curgroup;
330   gint                   maxgroup;
331 
332   GstIndexResolverMethod method;
333   GstIndexResolver       resolver;
334   gpointer               resolver_user_data;
335   GDestroyNotify         resolver_user_data_destroy;
336 
337   GstIndexFilter         filter;
338   gpointer               filter_user_data;
339   GDestroyNotify         filter_user_data_destroy;
340 
341   GHashTable            *writers;
342   gint                   last_id;
343 
344   /*< private >*/
345   gpointer _gst_reserved[GST_PADDING];
346 };
347 
348 struct _GstIndexClass {
349   GstObjectClass parent_class;
350 
351   /*< protected >*/
352   gboolean      (*get_writer_id)        (GstIndex *index, gint *id, gchar *writer);
353 
354   void          (*commit)               (GstIndex *index, gint id);
355 
356   /* abstract methods */
357   void          (*add_entry)            (GstIndex *index, GstIndexEntry *entry);
358 
359   GstIndexEntry* (*get_assoc_entry)     (GstIndex *index, gint id,
360                                          GstIndexLookupMethod method, GstIndexAssociationFlags flags,
361                                          GstFormat format, gint64 value,
362                                          GCompareDataFunc func,
363                                          gpointer user_data);
364   /* signals */
365   void          (*entry_added)          (GstIndex *index, GstIndexEntry *entry);
366 
367   /*< private >*/
368   gpointer _gst_reserved[GST_PADDING];
369 };
370 
371 static
372 GType                   gst_index_get_type              (void);
373 
374 #if 0
375 GstIndex*               gst_index_new                   (void);
376 #endif
377 void                    gst_index_commit                (GstIndex *index, gint id);
378 
379 #if 0
380 gint                    gst_index_get_group             (GstIndex *index);
381 gint                    gst_index_new_group             (GstIndex *index);
382 gboolean                gst_index_set_group             (GstIndex *index, gint groupnum);
383 
384 void                    gst_index_set_certainty         (GstIndex *index,
385                                                          GstIndexCertainty certainty);
386 GstIndexCertainty       gst_index_get_certainty         (GstIndex *index);
387 
388 static
389 void                    gst_index_set_filter            (GstIndex *index,
390                                                          GstIndexFilter filter, gpointer user_data);
391 static
392 void                    gst_index_set_filter_full       (GstIndex *index,
393                                                          GstIndexFilter filter, gpointer user_data,
394                                                          GDestroyNotify user_data_destroy);
395 
396 void                    gst_index_set_resolver          (GstIndex *index,
397                                                          GstIndexResolver resolver, gpointer user_data);
398 void                    gst_index_set_resolver_full     (GstIndex *index, GstIndexResolver resolver,
399                                                          gpointer user_data,
400                                                          GDestroyNotify user_data_destroy);
401 #endif
402 
403 static
404 gboolean                gst_index_get_writer_id         (GstIndex *index, GstObject *writer, gint *id);
405 
406 #if 0
407 GstIndexEntry*          gst_index_add_format            (GstIndex *index, gint id, GstFormat format);
408 #endif
409 
410 static
411 GstIndexEntry*          gst_index_add_associationv      (GstIndex * index, gint id, GstIndexAssociationFlags flags,
412                                                          gint n, const GstIndexAssociation * list);
413 #if 0
414 GstIndexEntry*          gst_index_add_association       (GstIndex *index, gint id, GstIndexAssociationFlags flags,
415                                                          GstFormat format, gint64 value, ...)
416 GstIndexEntry*          gst_index_add_object            (GstIndex *index, gint id, gchar *key,
417                                                          GType type, gpointer object);
418 #endif
419 
420 static
421 GstIndexEntry*          gst_index_add_id                (GstIndex *index, gint id,
422                                                          gchar *description);
423 
424 static
425 GstIndexEntry*          gst_index_get_assoc_entry       (GstIndex *index, gint id,
426                                                          GstIndexLookupMethod method, GstIndexAssociationFlags flags,
427                                                          GstFormat format, gint64 value);
428 static
429 GstIndexEntry*          gst_index_get_assoc_entry_full  (GstIndex *index, gint id,
430                                                          GstIndexLookupMethod method, GstIndexAssociationFlags flags,
431                                                          GstFormat format, gint64 value,
432                                                          GCompareDataFunc func,
433                                                          gpointer user_data);
434 
435 /* working with index entries */
436 static
437 GType gst_index_entry_get_type (void);
438 static
439 GstIndexEntry *         gst_index_entry_copy            (GstIndexEntry *entry);
440 static
441 void                    gst_index_entry_free            (GstIndexEntry *entry);
442 static
443 gboolean                gst_index_entry_assoc_map       (GstIndexEntry *entry,
444                                                          GstFormat format, gint64 *value);
445 
446 G_END_DECLS
447 
448 #endif /* __GST_INDEX_H__ */
449