2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2005 Wim Taymans <wim@fluendo.com>
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Library General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Library General Public License for more details.
15 * You should have received a copy of the GNU Library General Public
16 * License along with this library; if not, write to the
17 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 * Boston, MA 02111-1307, USA.
21 #ifndef __GST_BASE_TRANSFORM_H__
22 #define __GST_BASE_TRANSFORM_H__
28 #define GST_TYPE_BASE_TRANSFORM (gst_base_transform_get_type())
29 #define GST_BASE_TRANSFORM(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_BASE_TRANSFORM,GstBaseTransform))
30 #define GST_BASE_TRANSFORM_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_BASE_TRANSFORM,GstBaseTransformClass))
31 #define GST_BASE_TRANSFORM_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS((obj),GST_TYPE_BASE_TRANSFORM,GstBaseTransformClass))
32 #define GST_IS_BASE_TRANSFORM(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_BASE_TRANSFORM))
33 #define GST_IS_BASE_TRANSFORM_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_BASE_TRANSFORM))
35 #define GST_BASE_TRANSFORM_CAST(obj) ((GstBaseTransform *)(obj))
38 * GST_BASE_TRANSFORM_SINK_NAME:
40 * The name of the templates for the sink pad.
42 #define GST_BASE_TRANSFORM_SINK_NAME "sink"
44 * GST_BASE_TRANSFORM_SRC_NAME:
46 * The name of the templates for the source pad.
48 #define GST_BASE_TRANSFORM_SRC_NAME "src"
51 * GST_BASE_TRANSFORM_SRC_PAD:
52 * @obj: base transform instance
54 * Gives the pointer to the source #GstPad object of the element.
58 #define GST_BASE_TRANSFORM_SRC_PAD(obj) (GST_BASE_TRANSFORM_CAST (obj)->srcpad)
61 * GST_BASE_TRANSFORM_SINK_PAD:
62 * @obj: base transform instance
64 * Gives the pointer to the sink #GstPad object of the element.
68 #define GST_BASE_TRANSFORM_SINK_PAD(obj) (GST_BASE_TRANSFORM_CAST (obj)->sinkpad)
71 * GST_BASE_TRANSFORM_FLOW_DROPPED:
73 * A #GstFlowReturn that can be returned from transform and transform_ip to
74 * indicate that no output buffer was generated.
78 #define GST_BASE_TRANSFORM_FLOW_DROPPED GST_FLOW_CUSTOM_SUCCESS
81 * GST_BASE_TRANSFORM_LOCK:
82 * @obj: base transform instance
84 * Obtain a lock to protect the transform function from concurrent access.
88 #define GST_BASE_TRANSFORM_LOCK(obj) g_mutex_lock (&GST_BASE_TRANSFORM_CAST (obj)->transform_lock)
91 * GST_BASE_TRANSFORM_UNLOCK:
92 * @obj: base transform instance
94 * Release the lock that protects the transform function from concurrent access.
98 #define GST_BASE_TRANSFORM_UNLOCK(obj) g_mutex_unlock (&GST_BASE_TRANSFORM_CAST (obj)->transform_lock)
100 typedef struct _GstBaseTransform GstBaseTransform;
101 typedef struct _GstBaseTransformClass GstBaseTransformClass;
102 typedef struct _GstBaseTransformPrivate GstBaseTransformPrivate;
107 * The opaque #GstBaseTransform data structure.
109 struct _GstBaseTransform {
113 /* source and sink pads */
117 /* Set by sub-class */
118 gboolean passthrough;
119 gboolean always_in_place;
121 GstCaps *cache_caps1;
122 gsize cache_caps1_size;
123 GstCaps *cache_caps2;
124 gsize cache_caps2_size;
125 gboolean have_same_caps;
129 gboolean have_segment;
131 /* MT-protected (with STREAM_LOCK) */
134 GMutex transform_lock;
137 GstBaseTransformPrivate *priv;
139 gpointer _gst_reserved[GST_PADDING_LARGE];
143 * GstBaseTransformClass:
144 * @parent_class: Element parent class
145 * @passthrough_on_same_caps: If set to TRUE, passthrough mode will be
146 * automatically enabled if the caps are the same.
147 * @transform_caps: Optional. Given the pad in this direction and the given
148 * caps, what caps are allowed on the other pad in this
150 * @fixate_caps: Optional. Given the pad in this direction and the given
151 * caps, fixate the caps on the other pad. The function takes
152 * ownership of @othercaps and returns a fixated version of
153 * @othercaps. @othercaps is not guaranteed to be writable.
154 * @accept_caps: Optional. Since 0.10.30
155 * Subclasses can override this method to check if @caps can be
156 * handled by the element. The default implementation might not be
157 * the most optimal way to check this in all cases.
158 * @set_caps: allows the subclass to be notified of the actual caps set.
159 * @query: Optional Since 0.10.36
160 * Handle a requested query. Subclasses that implement this
161 * should must chain up to the parent if they didn't handle the
163 * @propose_allocation: Propose buffer allocation parameters for upstream elements.
164 * This function must be implemented if the element reads or
165 * writes the buffer content. The default implementation is NULL.
166 * @decide_allocation: Setup the allocation parameters for allocating output
167 * buffers. The passed in query contains the result of the
168 * downstream allocation query. This function is only called
169 * when not operating in passthrough mode. The default
170 * implementation is NULL.
171 * @transform_size: Optional. Given the size of a buffer in the given direction
172 * with the given caps, calculate the size in bytes of a buffer
173 * on the other pad with the given other caps.
174 * The default implementation uses get_unit_size and keeps
175 * the number of units the same.
176 * @get_unit_size: Required if the transform is not in-place.
177 * get the size in bytes of one unit for the given caps.
179 * Called when the element starts processing.
180 * Allows opening external resources.
182 * Called when the element stops processing.
183 * Allows closing external resources.
184 * @sink_event: Optional.
185 * Event handler on the sink pad. The default implementation
186 * handles the event and forwards it downstream.
187 * @src_event: Optional.
188 * Event handler on the source pad. The default implementation
189 * handles the event and forwards it upstream.
190 * @prepare_output_buffer: Optional.
191 * Subclasses can override this to do their own
192 * allocation of output buffers. Elements that only do
193 * analysis can return a subbuffer or even just
194 * return a reference to the input buffer (if in
195 * passthrough mode). The default implementation will
196 * use the negotiated allocator or bufferpool and
197 * transform_size to allocate an output buffer or it
198 * will return the input buffer in passthrough mode.
199 * @copy_metadata: Optional.
200 * Copy the metadata from the input buffer to the output buffer.
201 * The default implementation will copy the flags, timestamps and
202 * offsets of the buffer.
203 * @before_transform: Optional. Since 0.10.22
204 * This method is called right before the base class will
205 * start processing. Dynamic properties or other delayed
206 * configuration could be performed in this method.
207 * @transform: Required if the element does not operate in-place.
208 * Transforms one incoming buffer to one outgoing buffer.
209 * The function is allowed to change size/timestamp/duration
210 * of the outgoing buffer.
211 * @transform_ip: Required if the element operates in-place.
212 * Transform the incoming buffer in-place.
214 * Subclasses can override any of the available virtual methods or not, as
215 * needed. At minimum either @transform or @transform_ip need to be overridden.
216 * If the element can overwrite the input data with the results (data is of the
217 * same type and quantity) it should provide @transform_ip.
219 struct _GstBaseTransformClass {
220 GstElementClass parent_class;
223 gboolean passthrough_on_same_caps;
225 /* virtual methods for subclasses */
226 GstCaps* (*transform_caps) (GstBaseTransform *trans,
227 GstPadDirection direction,
228 GstCaps *caps, GstCaps *filter);
229 GstCaps* (*fixate_caps) (GstBaseTransform *trans,
230 GstPadDirection direction, GstCaps *caps,
232 gboolean (*accept_caps) (GstBaseTransform *trans, GstPadDirection direction,
234 gboolean (*set_caps) (GstBaseTransform *trans, GstCaps *incaps,
236 gboolean (*query) (GstBaseTransform *trans, GstPadDirection direction,
239 /* propose allocation query parameters for input buffers */
240 gboolean (*propose_allocation) (GstBaseTransform *trans, GstQuery *query);
241 /* decide allocation query for output buffers */
242 gboolean (*decide_allocation) (GstBaseTransform *trans, GstQuery *query);
245 gboolean (*transform_size) (GstBaseTransform *trans,
246 GstPadDirection direction,
247 GstCaps *caps, gsize size,
248 GstCaps *othercaps, gsize *othersize);
250 gboolean (*get_unit_size) (GstBaseTransform *trans, GstCaps *caps,
254 gboolean (*start) (GstBaseTransform *trans);
255 gboolean (*stop) (GstBaseTransform *trans);
257 /* sink and src pad event handlers */
258 gboolean (*sink_event) (GstBaseTransform *trans, GstEvent *event);
259 gboolean (*src_event) (GstBaseTransform *trans, GstEvent *event);
261 GstFlowReturn (*prepare_output_buffer) (GstBaseTransform * trans,
262 GstBuffer *input, GstBuffer **outbuf);
264 gboolean (*copy_metadata) (GstBaseTransform * trans, GstBuffer *input,
267 void (*before_transform) (GstBaseTransform *trans, GstBuffer *buffer);
270 GstFlowReturn (*transform) (GstBaseTransform *trans, GstBuffer *inbuf,
272 GstFlowReturn (*transform_ip) (GstBaseTransform *trans, GstBuffer *buf);
275 gpointer _gst_reserved[GST_PADDING_LARGE];
278 GType gst_base_transform_get_type (void);
280 void gst_base_transform_set_passthrough (GstBaseTransform *trans,
281 gboolean passthrough);
282 gboolean gst_base_transform_is_passthrough (GstBaseTransform *trans);
284 void gst_base_transform_set_in_place (GstBaseTransform *trans,
286 gboolean gst_base_transform_is_in_place (GstBaseTransform *trans);
288 void gst_base_transform_update_qos (GstBaseTransform *trans,
290 GstClockTimeDiff diff,
291 GstClockTime timestamp);
292 void gst_base_transform_set_qos_enabled (GstBaseTransform *trans,
294 gboolean gst_base_transform_is_qos_enabled (GstBaseTransform *trans);
296 void gst_base_transform_set_gap_aware (GstBaseTransform *trans,
299 void gst_base_transform_suggest (GstBaseTransform *trans,
300 GstCaps *caps, gsize size);
301 void gst_base_transform_reconfigure (GstBaseTransform *trans);
304 #endif /* __GST_BASE_TRANSFORM_H__ */