1/* GStreamer
2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2005 Wim Taymans <wim@fluendo.com>
4 *
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.
9 *
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.
14 *
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., 51 Franklin St, Fifth Floor,
18 * Boston, MA 02110-1301, USA.
19 */
20
21#ifndef __GST_BASE_TRANSFORM_H__
22#define __GST_BASE_TRANSFORM_H__
23
24#include <gst/gst.h>
25#include <gst/base/base-prelude.h>
26
27G_BEGIN_DECLS
28
29#define GST_TYPE_BASE_TRANSFORM (gst_base_transform_get_type())
30#define GST_BASE_TRANSFORM(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_BASE_TRANSFORM,GstBaseTransform))
31#define GST_BASE_TRANSFORM_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_BASE_TRANSFORM,GstBaseTransformClass))
32#define GST_BASE_TRANSFORM_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS((obj),GST_TYPE_BASE_TRANSFORM,GstBaseTransformClass))
33#define GST_IS_BASE_TRANSFORM(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_BASE_TRANSFORM))
34#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))
36
37/**
38 * GST_BASE_TRANSFORM_SINK_NAME:
39 *
40 * The name of the templates for the sink pad.
41 */
42#define GST_BASE_TRANSFORM_SINK_NAME "sink"
43/**
44 * GST_BASE_TRANSFORM_SRC_NAME:
45 *
46 * The name of the templates for the source pad.
47 */
48#define GST_BASE_TRANSFORM_SRC_NAME "src"
49
50/**
51 * GST_BASE_TRANSFORM_SRC_PAD:
52 * @obj: base transform instance
53 *
54 * Gives the pointer to the source #GstPad object of the element.
55 */
56#define GST_BASE_TRANSFORM_SRC_PAD(obj) (GST_BASE_TRANSFORM_CAST (obj)->srcpad)
57
58/**
59 * GST_BASE_TRANSFORM_SINK_PAD:
60 * @obj: base transform instance
61 *
62 * Gives the pointer to the sink #GstPad object of the element.
63 */
64#define GST_BASE_TRANSFORM_SINK_PAD(obj) (GST_BASE_TRANSFORM_CAST (obj)->sinkpad)
65
66/**
67 * GST_BASE_TRANSFORM_FLOW_DROPPED:
68 *
69 * A #GstFlowReturn that can be returned from transform and transform_ip to
70 * indicate that no output buffer was generated.
71 */
72#define GST_BASE_TRANSFORM_FLOW_DROPPED GST_FLOW_CUSTOM_SUCCESS
73
74typedef struct _GstBaseTransform GstBaseTransform;
75typedef struct _GstBaseTransformClass GstBaseTransformClass;
76typedef struct _GstBaseTransformPrivate GstBaseTransformPrivate;
77
78/**
79 * GstBaseTransform:
80 *
81 * The opaque #GstBaseTransform data structure.
82 */
83struct _GstBaseTransform {
84 GstElement element;
85
86 /*< protected >*/
87 /* source and sink pads */
88 GstPad *sinkpad;
89 GstPad *srcpad;
90
91 /* MT-protected (with STREAM_LOCK) */
92 gboolean have_segment;
93 GstSegment segment;
94 /* Default submit_input_buffer places the buffer here,
95 * for consumption by the generate_output method: */
96 GstBuffer *queued_buf;
97
98 /*< private >*/
99 GstBaseTransformPrivate *priv;
100
101 gpointer _gst_reserved[GST_PADDING_LARGE-1];
102};
103
104/**
105 * GstBaseTransformClass:
106 * @parent_class: Element parent class
107 * @passthrough_on_same_caps: If set to %TRUE, passthrough mode will be
108 * automatically enabled if the caps are the same.
109 * Set to %FALSE by default.
110 * @transform_ip_on_passthrough: If set to %TRUE, @transform_ip will be called in
111 * passthrough mode. The passed buffer might not be
112 * writable. When %FALSE, neither @transform nor
113 * @transform_ip will be called in passthrough mode.
114 * Set to %TRUE by default.
115 * @transform_caps: Optional. Given the pad in this direction and the given
116 * caps, what caps are allowed on the other pad in this
117 * element ?
118 * @fixate_caps: Optional. Given the pad in this direction and the given
119 * caps, fixate the caps on the other pad. The function takes
120 * ownership of @othercaps and returns a fixated version of
121 * @othercaps. @othercaps is not guaranteed to be writable.
122 * @accept_caps: Optional.
123 * Subclasses can override this method to check if @caps can be
124 * handled by the element. The default implementation might not be
125 * the most optimal way to check this in all cases.
126 * @set_caps: Allows the subclass to be notified of the actual caps set.
127 * @query: Optional.
128 * Handle a requested query. Subclasses that implement this
129 * must chain up to the parent if they didn't handle the
130 * query
131 * @decide_allocation: Setup the allocation parameters for allocating output
132 * buffers. The passed in query contains the result of the
133 * downstream allocation query. This function is only called
134 * when not operating in passthrough mode. The default
135 * implementation will remove all memory dependent metadata.
136 * If there is a @filter_meta method implementation, it will
137 * be called for all metadata API in the downstream query,
138 * otherwise the metadata API is removed.
139 * @filter_meta: Return %TRUE if the metadata API should be proposed in the
140 * upstream allocation query. The default implementation is %NULL
141 * and will cause all metadata to be removed.
142 * @propose_allocation: Propose buffer allocation parameters for upstream elements.
143 * This function must be implemented if the element reads or
144 * writes the buffer content. The query that was passed to
145 * the decide_allocation is passed in this method (or %NULL
146 * when the element is in passthrough mode). The default
147 * implementation will pass the query downstream when in
148 * passthrough mode and will copy all the filtered metadata
149 * API in non-passthrough mode.
150 * @transform_size: Optional. Given the size of a buffer in the given direction
151 * with the given caps, calculate the size in bytes of a buffer
152 * on the other pad with the given other caps.
153 * The default implementation uses get_unit_size and keeps
154 * the number of units the same.
155 * @get_unit_size: Required if the transform is not in-place.
156 * Get the size in bytes of one unit for the given caps.
157 * @start: Optional.
158 * Called when the element starts processing.
159 * Allows opening external resources.
160 * @stop: Optional.
161 * Called when the element stops processing.
162 * Allows closing external resources.
163 * @sink_event: Optional.
164 * Event handler on the sink pad. The default implementation
165 * handles the event and forwards it downstream.
166 * @src_event: Optional.
167 * Event handler on the source pad. The default implementation
168 * handles the event and forwards it upstream.
169 * @prepare_output_buffer: Optional.
170 * Subclasses can override this to do their own
171 * allocation of output buffers. Elements that only do
172 * analysis can return a subbuffer or even just
173 * return a reference to the input buffer (if in
174 * passthrough mode). The default implementation will
175 * use the negotiated allocator or bufferpool and
176 * transform_size to allocate an output buffer or it
177 * will return the input buffer in passthrough mode.
178 * @copy_metadata: Optional.
179 * Copy the metadata from the input buffer to the output buffer.
180 * The default implementation will copy the flags, timestamps and
181 * offsets of the buffer.
182 * @transform_meta: Optional. Transform the metadata on the input buffer to the
183 * output buffer. By default this method copies all meta without
184 * tags. Subclasses can implement this method and return %TRUE if
185 * the metadata is to be copied.
186 * @before_transform: Optional.
187 * This method is called right before the base class will
188 * start processing. Dynamic properties or other delayed
189 * configuration could be performed in this method.
190 * @transform: Required if the element does not operate in-place.
191 * Transforms one incoming buffer to one outgoing buffer.
192 * The function is allowed to change size/timestamp/duration
193 * of the outgoing buffer.
194 * @transform_ip: Required if the element operates in-place.
195 * Transform the incoming buffer in-place.
196 * @submit_input_buffer: Function which accepts a new input buffer and pre-processes it.
197 * The default implementation performs caps (re)negotiation, then
198 * QoS if needed, and places the input buffer into the @queued_buf
199 * member variable. If the buffer is dropped due to QoS, it returns
200 * GST_BASE_TRANSFORM_FLOW_DROPPED. If this input buffer is not
201 * contiguous with any previous input buffer, then @is_discont
202 * is set to %TRUE. (Since: 1.6)
203 * @generate_output: Called after each new input buffer is submitted repeatedly
204 * until it either generates an error or fails to generate an output
205 * buffer. The default implementation takes the contents of the
206 * @queued_buf variable, generates an output buffer if needed
207 * by calling the class @prepare_output_buffer, and then
208 * calls either @transform or @transform_ip. Elements that don't
209 * do 1-to-1 transformations of input to output buffers can either
210 * return GST_BASE_TRANSFORM_FLOW_DROPPED or simply not generate
211 * an output buffer until they are ready to do so. (Since: 1.6)
212 *
213 * Subclasses can override any of the available virtual methods or not, as
214 * needed. At minimum either @transform or @transform_ip need to be overridden.
215 * If the element can overwrite the input data with the results (data is of the
216 * same type and quantity) it should provide @transform_ip.
217 */
218struct _GstBaseTransformClass {
219 GstElementClass parent_class;
220
221 /*< public >*/
222 gboolean passthrough_on_same_caps;
223 gboolean transform_ip_on_passthrough;
224
225 /* virtual methods for subclasses */
226 GstCaps* (*transform_caps) (GstBaseTransform *trans,
227 GstPadDirection direction,
228 GstCaps *caps, GstCaps *filter);
229 /**
230 * GstBaseTransformClass::fixate_caps:
231 * @othercaps: (transfer full):
232 */
233 GstCaps* (*fixate_caps) (GstBaseTransform *trans,
234 GstPadDirection direction, GstCaps *caps,
235 GstCaps *othercaps);
236 gboolean (*accept_caps) (GstBaseTransform *trans, GstPadDirection direction,
237 GstCaps *caps);
238 gboolean (*set_caps) (GstBaseTransform *trans, GstCaps *incaps,
239 GstCaps *outcaps);
240 gboolean (*query) (GstBaseTransform *trans, GstPadDirection direction,
241 GstQuery *query);
242
243 /* decide allocation query for output buffers */
244 gboolean (*decide_allocation) (GstBaseTransform *trans, GstQuery *query);
245 gboolean (*filter_meta) (GstBaseTransform *trans, GstQuery *query,
246 GType api, const GstStructure *params);
247
248 /* propose allocation query parameters for input buffers */
249 gboolean (*propose_allocation) (GstBaseTransform *trans, GstQuery *decide_query,
250 GstQuery *query);
251
252 /**
253 * GstBaseTransformClass::transform_size:
254 * @othersize: (out):
255 */
256 gboolean (*transform_size) (GstBaseTransform *trans,
257 GstPadDirection direction,
258 GstCaps *caps, gsize size,
259 GstCaps *othercaps, gsize *othersize);
260
261 /**
262 * GstBaseTransformClass::get_unit_size:
263 * @size: (out):
264 */
265 gboolean (*get_unit_size) (GstBaseTransform *trans, GstCaps *caps,
266 gsize *size);
267
268 /* states */
269 gboolean (*start) (GstBaseTransform *trans);
270 gboolean (*stop) (GstBaseTransform *trans);
271
272 /* sink and src pad event handlers */
273 /**
274 * GstBaseTransformClass::sink_event:
275 * @event: (transfer full):
276 */
277 gboolean (*sink_event) (GstBaseTransform *trans, GstEvent *event);
278 /**
279 * GstBaseTransformClass::src_event:
280 * @event: (transfer full):
281 */
282 gboolean (*src_event) (GstBaseTransform *trans, GstEvent *event);
283
284 /**
285 * GstBaseTransformClass::prepare_output_buffer:
286 * @outbuf: (out):
287 */
288 GstFlowReturn (*prepare_output_buffer) (GstBaseTransform * trans,
289 GstBuffer *input, GstBuffer **outbuf);
290
291 /* metadata */
292 gboolean (*copy_metadata) (GstBaseTransform *trans, GstBuffer *input,
293 GstBuffer *outbuf);
294 gboolean (*transform_meta) (GstBaseTransform *trans, GstBuffer *outbuf,
295 GstMeta *meta, GstBuffer *inbuf);
296
297 void (*before_transform) (GstBaseTransform *trans, GstBuffer *buffer);
298
299 /* transform */
300 GstFlowReturn (*transform) (GstBaseTransform *trans, GstBuffer *inbuf,
301 GstBuffer *outbuf);
302 GstFlowReturn (*transform_ip) (GstBaseTransform *trans, GstBuffer *buf);
303
304 GstFlowReturn (*submit_input_buffer) (GstBaseTransform *trans, gboolean is_discont, GstBuffer *input);
305
306 /**
307 * GstBaseTransformClass::generate_output:
308 * @outbuf: (out):
309 */
310 GstFlowReturn (*generate_output) (GstBaseTransform *trans, GstBuffer **outbuf);
311
312 /*< private >*/
313 gpointer _gst_reserved[GST_PADDING_LARGE - 2];
314};
315
316GST_BASE_API
317GType gst_base_transform_get_type (void);
318
319GST_BASE_API
320void gst_base_transform_set_passthrough (GstBaseTransform *trans,
321 gboolean passthrough);
322GST_BASE_API
323gboolean gst_base_transform_is_passthrough (GstBaseTransform *trans);
324
325GST_BASE_API
326void gst_base_transform_set_in_place (GstBaseTransform *trans,
327 gboolean in_place);
328GST_BASE_API
329gboolean gst_base_transform_is_in_place (GstBaseTransform *trans);
330
331GST_BASE_API
332void gst_base_transform_update_qos (GstBaseTransform *trans,
333 gdouble proportion,
334 GstClockTimeDiff diff,
335 GstClockTime timestamp);
336GST_BASE_API
337void gst_base_transform_set_qos_enabled (GstBaseTransform *trans,
338 gboolean enabled);
339GST_BASE_API
340gboolean gst_base_transform_is_qos_enabled (GstBaseTransform *trans);
341
342GST_BASE_API
343void gst_base_transform_set_gap_aware (GstBaseTransform *trans,
344 gboolean gap_aware);
345GST_BASE_API
346void gst_base_transform_set_prefer_passthrough (GstBaseTransform *trans,
347 gboolean prefer_passthrough);
348GST_BASE_API
349GstBufferPool * gst_base_transform_get_buffer_pool (GstBaseTransform *trans);
350
351GST_BASE_API
352void gst_base_transform_get_allocator (GstBaseTransform *trans,
353 GstAllocator **allocator,
354 GstAllocationParams *params);
355GST_BASE_API
356void gst_base_transform_reconfigure_sink (GstBaseTransform *trans);
357
358GST_BASE_API
359void gst_base_transform_reconfigure_src (GstBaseTransform *trans);
360
361GST_BASE_API
362gboolean gst_base_transform_update_src_caps (GstBaseTransform *trans,
363 GstCaps *updated_caps);
364
365GST_BASE_API
366gboolean gst_base_transform_reconfigure (GstBaseTransform * trans);
367
368G_DEFINE_AUTOPTR_CLEANUP_FUNC(GstBaseTransform, gst_object_unref)
369
370G_END_DECLS
371
372#endif /* __GST_BASE_TRANSFORM_H__ */
373

source code of include/gstreamer-1.0/gst/base/gstbasetransform.h