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
80 typedef struct _GstBaseTransform GstBaseTransform;
81 typedef struct _GstBaseTransformClass GstBaseTransformClass;
82 typedef struct _GstBaseTransformPrivate GstBaseTransformPrivate;
87 * The opaque #GstBaseTransform data structure.
89 struct _GstBaseTransform {
93 /* source and sink pads */
97 /* Set by sub-class */
99 gboolean always_in_place;
101 GstCaps *cache_caps1;
102 gsize cache_caps1_size;
103 GstCaps *cache_caps2;
104 gsize cache_caps2_size;
105 gboolean have_same_caps;
109 gboolean have_segment;
111 /* MT-protected (with STREAM_LOCK) */
115 GstBaseTransformPrivate *priv;
117 gpointer _gst_reserved[GST_PADDING_LARGE];
121 * GstBaseTransformClass:
122 * @parent_class: Element parent class
123 * @passthrough_on_same_caps: If set to TRUE, passthrough mode will be
124 * automatically enabled if the caps are the same.
125 * @transform_caps: Optional. Given the pad in this direction and the given
126 * caps, what caps are allowed on the other pad in this
128 * @fixate_caps: Optional. Given the pad in this direction and the given
129 * caps, fixate the caps on the other pad. The function takes
130 * ownership of @othercaps and returns a fixated version of
131 * @othercaps. @othercaps is not guaranteed to be writable.
132 * @accept_caps: Optional. Since 0.10.30
133 * Subclasses can override this method to check if @caps can be
134 * handled by the element. The default implementation might not be
135 * the most optimal way to check this in all cases.
136 * @set_caps: allows the subclass to be notified of the actual caps set.
137 * @query: Optional Since 0.10.36
138 * Handle a requested query. Subclasses that implement this
139 * should must chain up to the parent if they didn't handle the
141 * @decide_allocation: Setup the allocation parameters for allocating output
142 * buffers. The passed in query contains the result of the
143 * downstream allocation query. This function is only called
144 * when not operating in passthrough mode. The default
145 * implementation will remove all memory dependent metadata.
146 * If there is ia @filter_meta method implementation, it will
147 * be called for all metadata API in the downstream query,
148 * otherwise the metadata API is removed.
149 * @filter_meta: Return TRUE if the metadata API should be proposed in the
150 * upstream allocation query. The default implementation is NULL
151 * and will cause all metadata to be removed.
152 * @propose_allocation: Propose buffer allocation parameters for upstream elements.
153 * This function must be implemented if the element reads or
154 * writes the buffer content. The query that was passed to
155 * the decide_allocation is passed in this method (or NULL
156 * when the element is in passthrough mode). The default
157 * implementation will pass the query downstream when in
158 * passthrough mode and will copy all the filtered metadata
159 * API in non-passthrough mode.
160 * @transform_size: Optional. Given the size of a buffer in the given direction
161 * with the given caps, calculate the size in bytes of a buffer
162 * on the other pad with the given other caps.
163 * The default implementation uses get_unit_size and keeps
164 * the number of units the same.
165 * @get_unit_size: Required if the transform is not in-place.
166 * get the size in bytes of one unit for the given caps.
168 * Called when the element starts processing.
169 * Allows opening external resources.
171 * Called when the element stops processing.
172 * Allows closing external resources.
173 * @sink_event: Optional.
174 * Event handler on the sink pad. The default implementation
175 * handles the event and forwards it downstream.
176 * @src_event: Optional.
177 * Event handler on the source pad. The default implementation
178 * handles the event and forwards it upstream.
179 * @prepare_output_buffer: Optional.
180 * Subclasses can override this to do their own
181 * allocation of output buffers. Elements that only do
182 * analysis can return a subbuffer or even just
183 * return a reference to the input buffer (if in
184 * passthrough mode). The default implementation will
185 * use the negotiated allocator or bufferpool and
186 * transform_size to allocate an output buffer or it
187 * will return the input buffer in passthrough mode.
188 * @copy_metadata: Optional.
189 * Copy the metadata from the input buffer to the output buffer.
190 * The default implementation will copy the flags, timestamps and
191 * offsets of the buffer.
192 * @transform_meta: Optional. Transform the metadata on the input buffer to the
193 * output buffer. By default this method is NULL and no
194 * metadata is copied. subclasses can implement this method and
195 * return TRUE if the metadata is to be copied.
196 * @before_transform: Optional. Since 0.10.22
197 * This method is called right before the base class will
198 * start processing. Dynamic properties or other delayed
199 * configuration could be performed in this method.
200 * @transform: Required if the element does not operate in-place.
201 * Transforms one incoming buffer to one outgoing buffer.
202 * The function is allowed to change size/timestamp/duration
203 * of the outgoing buffer.
204 * @transform_ip: Required if the element operates in-place.
205 * Transform the incoming buffer in-place.
207 * Subclasses can override any of the available virtual methods or not, as
208 * needed. At minimum either @transform or @transform_ip need to be overridden.
209 * If the element can overwrite the input data with the results (data is of the
210 * same type and quantity) it should provide @transform_ip.
212 struct _GstBaseTransformClass {
213 GstElementClass parent_class;
216 gboolean passthrough_on_same_caps;
218 /* virtual methods for subclasses */
219 GstCaps* (*transform_caps) (GstBaseTransform *trans,
220 GstPadDirection direction,
221 GstCaps *caps, GstCaps *filter);
222 GstCaps* (*fixate_caps) (GstBaseTransform *trans,
223 GstPadDirection direction, GstCaps *caps,
225 gboolean (*accept_caps) (GstBaseTransform *trans, GstPadDirection direction,
227 gboolean (*set_caps) (GstBaseTransform *trans, GstCaps *incaps,
229 gboolean (*query) (GstBaseTransform *trans, GstPadDirection direction,
232 /* decide allocation query for output buffers */
233 gboolean (*decide_allocation) (GstBaseTransform *trans, GstQuery *query);
234 gboolean (*filter_meta) (GstBaseTransform *trans, GstQuery *query, GType api);
236 /* propose allocation query parameters for input buffers */
237 gboolean (*propose_allocation) (GstBaseTransform *trans, GstQuery *decide_query,
241 gboolean (*transform_size) (GstBaseTransform *trans,
242 GstPadDirection direction,
243 GstCaps *caps, gsize size,
244 GstCaps *othercaps, gsize *othersize);
246 gboolean (*get_unit_size) (GstBaseTransform *trans, GstCaps *caps,
250 gboolean (*start) (GstBaseTransform *trans);
251 gboolean (*stop) (GstBaseTransform *trans);
253 /* sink and src pad event handlers */
254 gboolean (*sink_event) (GstBaseTransform *trans, GstEvent *event);
255 gboolean (*src_event) (GstBaseTransform *trans, GstEvent *event);
257 GstFlowReturn (*prepare_output_buffer) (GstBaseTransform * trans,
258 GstBuffer *input, GstBuffer **outbuf);
261 gboolean (*copy_metadata) (GstBaseTransform *trans, GstBuffer *input,
263 gboolean (*transform_meta) (GstBaseTransform *trans, GstBuffer *outbuf,
264 GstMeta *meta, GstBuffer *inbuf);
266 void (*before_transform) (GstBaseTransform *trans, GstBuffer *buffer);
269 GstFlowReturn (*transform) (GstBaseTransform *trans, GstBuffer *inbuf,
271 GstFlowReturn (*transform_ip) (GstBaseTransform *trans, GstBuffer *buf);
274 gpointer _gst_reserved[GST_PADDING_LARGE];
277 GType gst_base_transform_get_type (void);
279 void gst_base_transform_set_passthrough (GstBaseTransform *trans,
280 gboolean passthrough);
281 gboolean gst_base_transform_is_passthrough (GstBaseTransform *trans);
283 void gst_base_transform_set_in_place (GstBaseTransform *trans,
285 gboolean gst_base_transform_is_in_place (GstBaseTransform *trans);
287 void gst_base_transform_update_qos (GstBaseTransform *trans,
289 GstClockTimeDiff diff,
290 GstClockTime timestamp);
291 void gst_base_transform_set_qos_enabled (GstBaseTransform *trans,
293 gboolean gst_base_transform_is_qos_enabled (GstBaseTransform *trans);
295 void gst_base_transform_set_gap_aware (GstBaseTransform *trans,
298 void gst_base_transform_reconfigure_sink (GstBaseTransform *trans);
299 void gst_base_transform_reconfigure_src (GstBaseTransform *trans);
302 #endif /* __GST_BASE_TRANSFORM_H__ */