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 * @propose_allocation: Propose buffer allocation parameters for upstream elements.
142 * This function must be implemented if the element reads or
143 * writes the buffer content. In passthrough mode, the
144 * default implementation will forward the ALLOCATION query
146 * @decide_allocation: Setup the allocation parameters for allocating output
147 * buffers. The passed in query contains the result of the
148 * downstream allocation query. This function is only called
149 * when not operating in passthrough mode. The default
150 * implementation is NULL.
151 * @transform_size: Optional. Given the size of a buffer in the given direction
152 * with the given caps, calculate the size in bytes of a buffer
153 * on the other pad with the given other caps.
154 * The default implementation uses get_unit_size and keeps
155 * the number of units the same.
156 * @get_unit_size: Required if the transform is not in-place.
157 * get the size in bytes of one unit for the given caps.
159 * Called when the element starts processing.
160 * Allows opening external resources.
162 * Called when the element stops processing.
163 * Allows closing external resources.
164 * @sink_event: Optional.
165 * Event handler on the sink pad. The default implementation
166 * handles the event and forwards it downstream.
167 * @src_event: Optional.
168 * Event handler on the source pad. The default implementation
169 * handles the event and forwards it upstream.
170 * @prepare_output_buffer: Optional.
171 * Subclasses can override this to do their own
172 * allocation of output buffers. Elements that only do
173 * analysis can return a subbuffer or even just
174 * return a reference to the input buffer (if in
175 * passthrough mode). The default implementation will
176 * use the negotiated allocator or bufferpool and
177 * transform_size to allocate an output buffer or it
178 * will return the input buffer in passthrough mode.
179 * @copy_metadata: Optional.
180 * Copy the metadata from the input buffer to the output buffer.
181 * The default implementation will copy the flags, timestamps and
182 * offsets of the buffer.
183 * @before_transform: Optional. Since 0.10.22
184 * This method is called right before the base class will
185 * start processing. Dynamic properties or other delayed
186 * configuration could be performed in this method.
187 * @transform: Required if the element does not operate in-place.
188 * Transforms one incoming buffer to one outgoing buffer.
189 * The function is allowed to change size/timestamp/duration
190 * of the outgoing buffer.
191 * @transform_ip: Required if the element operates in-place.
192 * Transform the incoming buffer in-place.
194 * Subclasses can override any of the available virtual methods or not, as
195 * needed. At minimum either @transform or @transform_ip need to be overridden.
196 * If the element can overwrite the input data with the results (data is of the
197 * same type and quantity) it should provide @transform_ip.
199 struct _GstBaseTransformClass {
200 GstElementClass parent_class;
203 gboolean passthrough_on_same_caps;
205 /* virtual methods for subclasses */
206 GstCaps* (*transform_caps) (GstBaseTransform *trans,
207 GstPadDirection direction,
208 GstCaps *caps, GstCaps *filter);
209 GstCaps* (*fixate_caps) (GstBaseTransform *trans,
210 GstPadDirection direction, GstCaps *caps,
212 gboolean (*accept_caps) (GstBaseTransform *trans, GstPadDirection direction,
214 gboolean (*set_caps) (GstBaseTransform *trans, GstCaps *incaps,
216 gboolean (*query) (GstBaseTransform *trans, GstPadDirection direction,
219 /* propose allocation query parameters for input buffers */
220 gboolean (*propose_allocation) (GstBaseTransform *trans, gboolean passthrough,
222 /* decide allocation query for output buffers */
223 gboolean (*decide_allocation) (GstBaseTransform *trans, GstQuery *query);
226 gboolean (*transform_size) (GstBaseTransform *trans,
227 GstPadDirection direction,
228 GstCaps *caps, gsize size,
229 GstCaps *othercaps, gsize *othersize);
231 gboolean (*get_unit_size) (GstBaseTransform *trans, GstCaps *caps,
235 gboolean (*start) (GstBaseTransform *trans);
236 gboolean (*stop) (GstBaseTransform *trans);
238 /* sink and src pad event handlers */
239 gboolean (*sink_event) (GstBaseTransform *trans, GstEvent *event);
240 gboolean (*src_event) (GstBaseTransform *trans, GstEvent *event);
242 GstFlowReturn (*prepare_output_buffer) (GstBaseTransform * trans,
243 GstBuffer *input, GstBuffer **outbuf);
245 gboolean (*copy_metadata) (GstBaseTransform * trans, GstBuffer *input,
248 void (*before_transform) (GstBaseTransform *trans, GstBuffer *buffer);
251 GstFlowReturn (*transform) (GstBaseTransform *trans, GstBuffer *inbuf,
253 GstFlowReturn (*transform_ip) (GstBaseTransform *trans, GstBuffer *buf);
256 gpointer _gst_reserved[GST_PADDING_LARGE];
259 GType gst_base_transform_get_type (void);
261 void gst_base_transform_set_passthrough (GstBaseTransform *trans,
262 gboolean passthrough);
263 gboolean gst_base_transform_is_passthrough (GstBaseTransform *trans);
265 void gst_base_transform_set_in_place (GstBaseTransform *trans,
267 gboolean gst_base_transform_is_in_place (GstBaseTransform *trans);
269 void gst_base_transform_update_qos (GstBaseTransform *trans,
271 GstClockTimeDiff diff,
272 GstClockTime timestamp);
273 void gst_base_transform_set_qos_enabled (GstBaseTransform *trans,
275 gboolean gst_base_transform_is_qos_enabled (GstBaseTransform *trans);
277 void gst_base_transform_set_gap_aware (GstBaseTransform *trans,
280 void gst_base_transform_suggest (GstBaseTransform *trans,
281 GstCaps *caps, gsize size);
282 void gst_base_transform_reconfigure (GstBaseTransform *trans);
285 #endif /* __GST_BASE_TRANSFORM_H__ */