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1 /* GStreamer
2  * Copyright (C) 2008 Nokia Corporation. All rights reserved.
3  *
4  * Contact: Stefan Kost <stefan.kost@nokia.com>
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Library General Public
8  * License as published by the Free Software Foundation; either
9  * version 2 of the License, or (at your option) any later version.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Library General Public License for more details.
15  *
16  * You should have received a copy of the GNU Library General Public
17  * License along with this library; if not, write to the
18  * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
19  * Boston, MA 02110-1301, USA.
20  */
21 
22 #ifndef __GST_BASE_PARSE_H__
23 #define __GST_BASE_PARSE_H__
24 
25 #include <gst/gst.h>
26 #include <gst/base/base-prelude.h>
27 
28 G_BEGIN_DECLS
29 
30 #define GST_TYPE_BASE_PARSE            (gst_base_parse_get_type())
31 #define GST_BASE_PARSE(obj)            (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_BASE_PARSE,GstBaseParse))
32 #define GST_BASE_PARSE_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_BASE_PARSE,GstBaseParseClass))
33 #define GST_BASE_PARSE_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS((obj),GST_TYPE_BASE_PARSE,GstBaseParseClass))
34 #define GST_IS_BASE_PARSE(obj)         (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_BASE_PARSE))
35 #define GST_IS_BASE_PARSE_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_BASE_PARSE))
36 #define GST_BASE_PARSE_CAST(obj)       ((GstBaseParse *)(obj))
37 
38 /**
39  * GST_BASE_PARSE_SRC_PAD:
40  * @obj: base parse instance
41  *
42  * Gives the pointer to the source #GstPad object of the element.
43  */
44 #define GST_BASE_PARSE_SRC_PAD(obj)    (GST_BASE_PARSE_CAST (obj)->srcpad)
45 
46 /**
47  * GST_BASE_PARSE_SINK_PAD:
48  * @obj: base parse instance
49  *
50  * Gives the pointer to the sink #GstPad object of the element.
51  */
52 #define GST_BASE_PARSE_SINK_PAD(obj)    (GST_BASE_PARSE_CAST (obj)->sinkpad)
53 
54 /**
55  * GST_BASE_PARSE_FLOW_DROPPED:
56  *
57  * A #GstFlowReturn that can be returned from
58  * #GstBaseParseClass::handle_frame to indicate that no output buffer was
59  * generated, or from #GstBaseParseClass::pre_push_frame to to forego
60  * pushing buffer.
61  */
62 #define GST_BASE_PARSE_FLOW_DROPPED     GST_FLOW_CUSTOM_SUCCESS
63 
64 /* not public API, use accessor macros below */
65 #define GST_BASE_PARSE_FLAG_LOST_SYNC (1 << 0)
66 #define GST_BASE_PARSE_FLAG_DRAINING  (1 << 1)
67 
68 /**
69  * GST_BASE_PARSE_LOST_SYNC:
70  * @parse: base parse instance
71  *
72  * Obtains current sync status.
73  */
74 #define GST_BASE_PARSE_LOST_SYNC(parse) (!!(GST_BASE_PARSE_CAST(parse)->flags & GST_BASE_PARSE_FLAG_LOST_SYNC))
75 
76 /**
77  * GST_BASE_PARSE_DRAINING:
78  * @parse: base parse instance
79  *
80  * Obtains current drain status (ie. whether EOS has been received and
81  * the parser is now processing the frames at the end of the stream)
82  */
83 #define GST_BASE_PARSE_DRAINING(parse)  (!!(GST_BASE_PARSE_CAST(parse)->flags & GST_BASE_PARSE_FLAG_DRAINING))
84 
85 /**
86  * GstBaseParseFrameFlags:
87  * @GST_BASE_PARSE_FRAME_FLAG_NONE: no flag
88  * @GST_BASE_PARSE_FRAME_FLAG_NEW_FRAME: set by baseclass if current frame
89  *   is passed for processing to the subclass for the first time
90  *   (and not set on subsequent calls with same data).
91  * @GST_BASE_PARSE_FRAME_FLAG_NO_FRAME: set to indicate this buffer should not be
92  *   counted as frame, e.g. if this frame is dependent on a previous one.
93  *   As it is not counted as a frame, bitrate increases but frame to time
94  *   conversions are maintained.
95  * @GST_BASE_PARSE_FRAME_FLAG_CLIP: @pre_push_frame can set this to indicate
96  *    that regular segment clipping can still be performed (as opposed to
97  *    any custom one having been done).
98  * @GST_BASE_PARSE_FRAME_FLAG_DROP: indicates to @finish_frame that the
99  *    the frame should be dropped (and might be handled internally by subclass)
100  * @GST_BASE_PARSE_FRAME_FLAG_QUEUE: indicates to @finish_frame that the
101  *    the frame should be queued for now and processed fully later
102  *    when the first non-queued frame is finished
103  *
104  * Flags to be used in a #GstBaseParseFrame.
105  */
106 typedef enum {
107   GST_BASE_PARSE_FRAME_FLAG_NONE         = 0,
108   GST_BASE_PARSE_FRAME_FLAG_NEW_FRAME    = (1 << 0),
109   GST_BASE_PARSE_FRAME_FLAG_NO_FRAME     = (1 << 1),
110   GST_BASE_PARSE_FRAME_FLAG_CLIP         = (1 << 2),
111   GST_BASE_PARSE_FRAME_FLAG_DROP         = (1 << 3),
112   GST_BASE_PARSE_FRAME_FLAG_QUEUE        = (1 << 4)
113 } GstBaseParseFrameFlags;
114 
115 /**
116  * GstBaseParseFrame:
117  * @buffer: input data to be parsed for frames.
118  * @out_buffer: output data.
119  * @offset: media specific offset of input frame
120  *   Note that a converter may have a different one on the frame's buffer.
121  * @overhead: subclass can set this to indicates the metadata overhead
122  *   for the given frame, which is then used to enable more accurate bitrate
123  *   computations. If this is -1, it is assumed that this frame should be
124  *   skipped in bitrate calculation.
125  * @flags: a combination of input and output #GstBaseParseFrameFlags that
126  *  convey additional context to subclass or allow subclass to tune
127  *  subsequent #GstBaseParse actions.
128  *
129  * Frame (context) data passed to each frame parsing virtual methods.  In
130  * addition to providing the data to be checked for a valid frame or an already
131  * identified frame, it conveys additional metadata or control information
132  * from and to the subclass w.r.t. the particular frame in question (rather
133  * than global parameters).  Some of these may apply to each parsing stage, others
134  * only to some a particular one.  These parameters are effectively zeroed at start
135  * of each frame's processing, i.e. parsing virtual method invocation sequence.
136  */
137 typedef struct {
138   GstBuffer * buffer;
139   GstBuffer * out_buffer;
140   guint       flags;
141   guint64     offset;
142   gint        overhead;
143   /*< private >*/
144   gint        size;
145   guint       _gst_reserved_i[2];
146   gpointer    _gst_reserved_p[2];
147   guint       _private_flags;
148 } GstBaseParseFrame;
149 
150 typedef struct _GstBaseParse GstBaseParse;
151 typedef struct _GstBaseParseClass GstBaseParseClass;
152 typedef struct _GstBaseParsePrivate GstBaseParsePrivate;
153 
154 /**
155  * GstBaseParse:
156  * @element: the parent element.
157  *
158  * The opaque #GstBaseParse data structure.
159  */
160 struct _GstBaseParse {
161   /*< public >*/
162   GstElement     element;
163 
164   /*< protected >*/
165   /* source and sink pads */
166   GstPad         *sinkpad;
167   GstPad         *srcpad;
168 
169   guint           flags;
170 
171   /* MT-protected (with STREAM_LOCK) */
172   GstSegment      segment;
173 
174   /*< private >*/
175   gpointer       _gst_reserved[GST_PADDING_LARGE];
176   GstBaseParsePrivate *priv;
177 };
178 
179 /**
180  * GstBaseParseClass:
181  * @parent_class: the parent class
182  * @start:          Optional.
183  *                  Called when the element starts processing.
184  *                  Allows opening external resources.
185  * @stop:           Optional.
186  *                  Called when the element stops processing.
187  *                  Allows closing external resources.
188  * @set_sink_caps:  Optional.
189  *                  Allows the subclass to be notified of the actual caps set.
190  * @get_sink_caps:  Optional.
191  *                  Allows the subclass to do its own sink get caps if needed.
192  * @handle_frame:   Parses the input data into valid frames as defined by subclass
193  *                  which should be passed to gst_base_parse_finish_frame().
194  *                  The frame's input buffer is guaranteed writable,
195  *                  whereas the input frame ownership is held by caller
196  *                  (so subclass should make a copy if it needs to hang on).
197  *                  Input buffer (data) is provided by baseclass with as much
198  *                  metadata set as possible by baseclass according to upstream
199  *                  information and/or subclass settings,
200  *                  though subclass may still set buffer timestamp and duration
201  *                  if desired.
202  * @convert:        Optional.
203  *                  Convert between formats.
204  * @sink_event:     Optional.
205  *                  Event handler on the sink pad. This function should chain
206  *                  up to the parent implementation to let the default handler
207  *                  run.
208  * @src_event:      Optional.
209  *                  Event handler on the source pad. Should chain up to the
210  *                  parent to let the default handler run.
211  * @pre_push_frame: Optional.
212  *                   Called just prior to pushing a frame (after any pending
213  *                   events have been sent) to give subclass a chance to perform
214  *                   additional actions at this time (e.g. tag sending) or to
215  *                   decide whether this buffer should be dropped or not
216  *                   (e.g. custom segment clipping).
217  * @detect:         Optional.
218  *                   Called until it doesn't return GST_FLOW_OK anymore for
219  *                   the first buffers. Can be used by the subclass to detect
220  *                   the stream format.
221  * @sink_query:     Optional.
222  *                   Query handler on the sink pad. This function should chain
223  *                   up to the parent implementation to let the default handler
224  *                   run (Since: 1.2)
225  * @src_query:      Optional.
226  *                   Query handler on the source pad. Should chain up to the
227  *                   parent to let the default handler run (Since: 1.2)
228  *
229  * Subclasses can override any of the available virtual methods or not, as
230  * needed. At minimum @handle_frame needs to be overridden.
231  */
232 struct _GstBaseParseClass {
233   GstElementClass parent_class;
234 
235   /*< public >*/
236   /* virtual methods for subclasses */
237 
238   gboolean      (*start)              (GstBaseParse * parse);
239 
240   gboolean      (*stop)               (GstBaseParse * parse);
241 
242   gboolean      (*set_sink_caps)      (GstBaseParse * parse,
243                                        GstCaps      * caps);
244 
245   /**
246    * GstBaseParseClass::handle_frame:
247    * @skipsize: (out):
248    *
249    * Parses the input data into valid frames as defined by subclass
250    * which should be passed to gst_base_parse_finish_frame().
251    * The frame's input buffer is guaranteed writable,
252    * whereas the input frame ownership is held by caller
253    * (so subclass should make a copy if it needs to hang on).
254    * Input buffer (data) is provided by baseclass with as much
255    * metadata set as possible by baseclass according to upstream
256    * information and/or subclass settings,
257    * though subclass may still set buffer timestamp and duration
258    * if desired.
259    */
260   GstFlowReturn (*handle_frame)       (GstBaseParse      * parse,
261                                        GstBaseParseFrame * frame,
262                                        gint              * skipsize);
263 
264   GstFlowReturn (*pre_push_frame)     (GstBaseParse      * parse,
265                                        GstBaseParseFrame * frame);
266 
267   gboolean      (*convert)            (GstBaseParse * parse,
268                                        GstFormat      src_format,
269                                        gint64         src_value,
270                                        GstFormat      dest_format,
271                                        gint64       * dest_value);
272 
273   gboolean      (*sink_event)         (GstBaseParse * parse,
274                                        GstEvent     * event);
275 
276   gboolean      (*src_event)          (GstBaseParse * parse,
277                                        GstEvent     * event);
278 
279   GstCaps *     (*get_sink_caps)      (GstBaseParse * parse,
280                                        GstCaps      * filter);
281 
282   GstFlowReturn (*detect)             (GstBaseParse * parse,
283                                        GstBuffer    * buffer);
284 
285   gboolean      (*sink_query)         (GstBaseParse * parse,
286                                        GstQuery     * query);
287 
288   gboolean      (*src_query)          (GstBaseParse * parse,
289                                        GstQuery     * query);
290 
291   /*< private >*/
292   gpointer       _gst_reserved[GST_PADDING_LARGE - 2];
293 };
294 
295 GST_BASE_API
296 GType           gst_base_parse_get_type (void);
297 
298 GST_BASE_API
299 GType           gst_base_parse_frame_get_type (void);
300 
301 GST_BASE_API
302 GstBaseParseFrame * gst_base_parse_frame_new  (GstBuffer              * buffer,
303                                                GstBaseParseFrameFlags   flags,
304                                                gint                     overhead);
305 GST_BASE_API
306 void            gst_base_parse_frame_init      (GstBaseParseFrame * frame);
307 
308 GST_BASE_API
309 GstBaseParseFrame * gst_base_parse_frame_copy  (GstBaseParseFrame * frame);
310 GST_BASE_API
311 void            gst_base_parse_frame_free      (GstBaseParseFrame * frame);
312 
313 GST_BASE_API
314 GstFlowReturn   gst_base_parse_push_frame      (GstBaseParse      * parse,
315                                                 GstBaseParseFrame * frame);
316 GST_BASE_API
317 GstFlowReturn   gst_base_parse_finish_frame    (GstBaseParse * parse,
318                                                 GstBaseParseFrame * frame,
319                                                 gint size);
320 GST_BASE_API
321 void            gst_base_parse_set_duration    (GstBaseParse      * parse,
322                                                 GstFormat           fmt,
323                                                 gint64              duration,
324                                                 gint                interval);
325 GST_BASE_API
326 void            gst_base_parse_set_average_bitrate (GstBaseParse   * parse,
327                                                     guint            bitrate);
328 GST_BASE_API
329 void            gst_base_parse_set_min_frame_size (GstBaseParse    * parse,
330                                                    guint             min_size);
331 GST_BASE_API
332 void            gst_base_parse_set_has_timing_info (GstBaseParse   * parse,
333                                                     gboolean         has_timing);
334 GST_BASE_API
335 void            gst_base_parse_drain           (GstBaseParse * parse);
336 
337 GST_BASE_API
338 void            gst_base_parse_set_syncable    (GstBaseParse * parse,
339                                                 gboolean       syncable);
340 GST_BASE_API
341 void            gst_base_parse_set_passthrough (GstBaseParse * parse,
342                                                 gboolean       passthrough);
343 GST_BASE_API
344 void            gst_base_parse_set_pts_interpolation (GstBaseParse * parse,
345                                                       gboolean pts_interpolate);
346 GST_BASE_API
347 void            gst_base_parse_set_infer_ts (GstBaseParse * parse,
348                                              gboolean infer_ts);
349 GST_BASE_API
350 void            gst_base_parse_set_frame_rate  (GstBaseParse * parse,
351                                                 guint          fps_num,
352                                                 guint          fps_den,
353                                                 guint          lead_in,
354                                                 guint          lead_out);
355 GST_BASE_API
356 void            gst_base_parse_set_latency     (GstBaseParse * parse,
357                                                 GstClockTime min_latency,
358                                                 GstClockTime max_latency);
359 GST_BASE_API
360 gboolean        gst_base_parse_convert_default (GstBaseParse * parse,
361                                                 GstFormat      src_format,
362                                                 gint64         src_value,
363                                                 GstFormat      dest_format,
364                                                 gint64       * dest_value);
365 GST_BASE_API
366 gboolean        gst_base_parse_add_index_entry (GstBaseParse * parse,
367                                                 guint64        offset,
368                                                 GstClockTime   ts,
369                                                 gboolean       key,
370                                                 gboolean       force);
371 GST_BASE_API
372 void            gst_base_parse_set_ts_at_offset (GstBaseParse *parse,
373                                                  gsize offset);
374 GST_BASE_API
375 void            gst_base_parse_merge_tags       (GstBaseParse  * parse,
376                                                  GstTagList    * tags,
377                                                  GstTagMergeMode mode);
378 
379 G_DEFINE_AUTOPTR_CLEANUP_FUNC(GstBaseParseFrame, gst_base_parse_frame_free)
380 
381 G_DEFINE_AUTOPTR_CLEANUP_FUNC(GstBaseParse, gst_object_unref)
382 
383 G_END_DECLS
384 
385 #endif /* __GST_BASE_PARSE_H__ */
386