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comparison DPF-Prymula-audioplugins/dpf/distrho/src/lv2/event.h @ 3:84e66ea83026

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DPF-Prymula-audioplugins-0.231015-2
author prymula <prymula76@outlook.com>
date Mon, 16 Oct 2023 21:53:34 +0200
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2:cf2cb71d31dd 3:84e66ea83026
1 /*
2 Copyright 2008-2016 David Robillard <http://drobilla.net>
3 Copyright 2006-2007 Lars Luthman <lars.luthman@gmail.com>
4
5 Permission to use, copy, modify, and/or distribute this software for any
6 purpose with or without fee is hereby granted, provided that the above
7 copyright notice and this permission notice appear in all copies.
8
9 THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18 /**
19 @defgroup event Event
20
21 Generic time-stamped events, see <http://lv2plug.in/ns/ext/event> for
22 details.
23
24 @{
25 */
26
27 #ifndef LV2_EVENT_H
28 #define LV2_EVENT_H
29
30 #define LV2_EVENT_URI "http://lv2plug.in/ns/ext/event" ///< http://lv2plug.in/ns/ext/event
31 #define LV2_EVENT_PREFIX LV2_EVENT_URI "#" ///< http://lv2plug.in/ns/ext/event#
32
33 #define LV2_EVENT__Event LV2_EVENT_PREFIX "Event" ///< http://lv2plug.in/ns/ext/event#Event
34 #define LV2_EVENT__EventPort LV2_EVENT_PREFIX "EventPort" ///< http://lv2plug.in/ns/ext/event#EventPort
35 #define LV2_EVENT__FrameStamp LV2_EVENT_PREFIX "FrameStamp" ///< http://lv2plug.in/ns/ext/event#FrameStamp
36 #define LV2_EVENT__TimeStamp LV2_EVENT_PREFIX "TimeStamp" ///< http://lv2plug.in/ns/ext/event#TimeStamp
37 #define LV2_EVENT__generatesTimeStamp LV2_EVENT_PREFIX "generatesTimeStamp" ///< http://lv2plug.in/ns/ext/event#generatesTimeStamp
38 #define LV2_EVENT__generic LV2_EVENT_PREFIX "generic" ///< http://lv2plug.in/ns/ext/event#generic
39 #define LV2_EVENT__inheritsEvent LV2_EVENT_PREFIX "inheritsEvent" ///< http://lv2plug.in/ns/ext/event#inheritsEvent
40 #define LV2_EVENT__inheritsTimeStamp LV2_EVENT_PREFIX "inheritsTimeStamp" ///< http://lv2plug.in/ns/ext/event#inheritsTimeStamp
41 #define LV2_EVENT__supportsEvent LV2_EVENT_PREFIX "supportsEvent" ///< http://lv2plug.in/ns/ext/event#supportsEvent
42 #define LV2_EVENT__supportsTimeStamp LV2_EVENT_PREFIX "supportsTimeStamp" ///< http://lv2plug.in/ns/ext/event#supportsTimeStamp
43
44 #define LV2_EVENT_AUDIO_STAMP 0 ///< Special timestamp type for audio frames
45
46 #include <stdint.h>
47
48 #ifdef __cplusplus
49 extern "C" {
50 #endif
51
52 /**
53 The best Pulses Per Quarter Note for tempo-based uint32_t timestamps.
54 Equal to 2^12 * 5 * 7 * 9 * 11 * 13 * 17, which is evenly divisble
55 by all integers from 1 through 18 inclusive, and powers of 2 up to 2^12.
56 */
57 static const uint32_t LV2_EVENT_PPQN = 3136573440U;
58
59 /**
60 An LV2 event (header only).
61
62 LV2 events are generic time-stamped containers for any type of event.
63 The type field defines the format of a given event's contents.
64
65 This struct defines the header of an LV2 event. An LV2 event is a single
66 chunk of POD (plain old data), usually contained in a flat buffer (see
67 LV2_EventBuffer below). Unless a required feature says otherwise, hosts may
68 assume a deep copy of an LV2 event can be created safely using a simple:
69
70 memcpy(ev_copy, ev, sizeof(LV2_Event) + ev->size); (or equivalent)
71 */
72 typedef struct {
73 /**
74 The frames portion of timestamp. The units used here can optionally be
75 set for a port (with the lv2ev:timeUnits property), otherwise this is
76 audio frames, corresponding to the sample_count parameter of the LV2 run
77 method (e.g. frame 0 is the first frame for that call to run).
78 */
79 uint32_t frames;
80
81 /**
82 The sub-frames portion of timestamp. The units used here can optionally
83 be set for a port (with the lv2ev:timeUnits property), otherwise this is
84 1/(2^32) of an audio frame.
85 */
86 uint32_t subframes;
87
88 /**
89 The type of this event, as a number which represents some URI
90 defining an event type. This value MUST be some value previously
91 returned from a call to the uri_to_id function defined in the LV2
92 URI map extension (see lv2_uri_map.h).
93 There are special rules which must be followed depending on the type
94 of an event. If the plugin recognizes an event type, the definition
95 of that event type will describe how to interpret the event, and
96 any required behaviour. Otherwise, if the type is 0, this event is a
97 non-POD event and lv2_event_unref MUST be called if the event is
98 'dropped' (see above). Even if the plugin does not understand an event,
99 it may pass the event through to an output by simply copying (and NOT
100 calling lv2_event_unref). These rules are designed to allow for generic
101 event handling plugins and large non-POD events, but with minimal hassle
102 on simple plugins that "don't care" about these more advanced features.
103 */
104 uint16_t type;
105
106 /**
107 The size of the data portion of this event in bytes, which immediately
108 follows. The header size (12 bytes) is not included in this value.
109 */
110 uint16_t size;
111
112 /* size bytes of data follow here */
113 } LV2_Event;
114
115
116 /**
117 A buffer of LV2 events (header only).
118
119 Like events (which this contains) an event buffer is a single chunk of POD:
120 the entire buffer (including contents) can be copied with a single memcpy.
121 The first contained event begins sizeof(LV2_EventBuffer) bytes after the
122 start of this struct.
123
124 After this header, the buffer contains an event header (defined by struct
125 LV2_Event), followed by that event's contents (padded to 64 bits), followed
126 by another header, etc:
127
128 | | | | | | |
129 | | | | | | | | | | | | | | | | | | | | | | | | |
130 |FRAMES |SUBFRMS|TYP|LEN|DATA..DATA..PAD|FRAMES | ...
131 */
132 typedef struct {
133 /**
134 The contents of the event buffer. This may or may not reside in the
135 same block of memory as this header, plugins must not assume either.
136 The host guarantees this points to at least capacity bytes of allocated
137 memory (though only size bytes of that are valid events).
138 */
139 uint8_t* data;
140
141 /**
142 The size of this event header in bytes (including everything).
143
144 This is to allow for extending this header in the future without
145 breaking binary compatibility. Whenever this header is copied,
146 it MUST be done using this field (and NOT the sizeof this struct).
147 */
148 uint16_t header_size;
149
150 /**
151 The type of the time stamps for events in this buffer.
152 As a special exception, '0' always means audio frames and subframes
153 (1/UINT32_MAX'th of a frame) in the sample rate passed to instantiate.
154
155 INPUTS: The host must set this field to the numeric ID of some URI
156 defining the meaning of the frames/subframes fields of contained events
157 (obtained by the LV2 URI Map uri_to_id function with the URI of this
158 extension as the 'map' argument, see lv2_uri_map.h). The host must
159 never pass a plugin a buffer which uses a stamp type the plugin does not
160 'understand'. The value of this field must never change, except when
161 connect_port is called on the input port, at which time the host MUST
162 have set the stamp_type field to the value that will be used for all
163 subsequent run calls.
164
165 OUTPUTS: The plugin may set this to any value that has been returned
166 from uri_to_id with the URI of this extension for a 'map' argument.
167 When connected to a buffer with connect_port, output ports MUST set this
168 field to the type of time stamp they will be writing. On any call to
169 connect_port on an event input port, the plugin may change this field on
170 any output port, it is the responsibility of the host to check if any of
171 these values have changed and act accordingly.
172 */
173 uint16_t stamp_type;
174
175 /**
176 The number of events in this buffer.
177
178 INPUTS: The host must set this field to the number of events contained
179 in the data buffer before calling run(). The plugin must not change
180 this field.
181
182 OUTPUTS: The plugin must set this field to the number of events it has
183 written to the buffer before returning from run(). Any initial value
184 should be ignored by the plugin.
185 */
186 uint32_t event_count;
187
188 /**
189 The size of the data buffer in bytes.
190 This is set by the host and must not be changed by the plugin.
191 The host is allowed to change this between run() calls.
192 */
193 uint32_t capacity;
194
195 /**
196 The size of the initial portion of the data buffer containing data.
197
198 INPUTS: The host must set this field to the number of bytes used
199 by all events it has written to the buffer (including headers)
200 before calling the plugin's run().
201 The plugin must not change this field.
202
203 OUTPUTS: The plugin must set this field to the number of bytes
204 used by all events it has written to the buffer (including headers)
205 before returning from run().
206 Any initial value should be ignored by the plugin.
207 */
208 uint32_t size;
209 } LV2_Event_Buffer;
210
211
212 /**
213 Opaque pointer to host data.
214 */
215 typedef void* LV2_Event_Callback_Data;
216
217
218 /**
219 Non-POD events feature.
220
221 To support this feature the host must pass an LV2_Feature struct to the
222 plugin's instantiate method with URI "http://lv2plug.in/ns/ext/event"
223 and data pointed to an instance of this struct. Note this feature
224 is not mandatory to support the event extension.
225 */
226 typedef struct {
227 /**
228 Opaque pointer to host data.
229
230 The plugin MUST pass this to any call to functions in this struct.
231 Otherwise, it must not be interpreted in any way.
232 */
233 LV2_Event_Callback_Data callback_data;
234
235 /**
236 Take a reference to a non-POD event.
237
238 If a plugin receives an event with type 0, it means the event is a
239 pointer to some object in memory and not a flat sequence of bytes
240 in the buffer. When receiving a non-POD event, the plugin already
241 has an implicit reference to the event. If the event is stored AND
242 passed to an output, lv2_event_ref MUST be called on that event.
243 If the event is only stored OR passed through, this is not necessary
244 (as the plugin already has 1 implicit reference).
245
246 @param event An event received at an input that will not be copied to
247 an output or stored in any way.
248
249 @param context The calling context. Like event types, this is a mapped
250 URI, see lv2_context.h. Simple plugin with just a run() method should
251 pass 0 here (the ID of the 'standard' LV2 run context). The host
252 guarantees that this function is realtime safe iff the context is
253 realtime safe.
254
255 PLUGINS THAT VIOLATE THESE RULES MAY CAUSE CRASHES AND MEMORY LEAKS.
256 */
257 uint32_t (*lv2_event_ref)(LV2_Event_Callback_Data callback_data,
258 LV2_Event* event);
259
260 /**
261 Drop a reference to a non-POD event.
262
263 If a plugin receives an event with type 0, it means the event is a
264 pointer to some object in memory and not a flat sequence of bytes
265 in the buffer. If the plugin does not pass the event through to
266 an output or store it internally somehow, it MUST call this function
267 on the event (more information on using non-POD events below).
268
269 @param event An event received at an input that will not be copied to an
270 output or stored in any way.
271
272 @param context The calling context. Like event types, this is a mapped
273 URI, see lv2_context.h. Simple plugin with just a run() method should
274 pass 0 here (the ID of the 'standard' LV2 run context). The host
275 guarantees that this function is realtime safe iff the context is
276 realtime safe.
277
278 PLUGINS THAT VIOLATE THESE RULES MAY CAUSE CRASHES AND MEMORY LEAKS.
279 */
280 uint32_t (*lv2_event_unref)(LV2_Event_Callback_Data callback_data,
281 LV2_Event* event);
282 } LV2_Event_Feature;
283
284 #ifdef __cplusplus
285 } /* extern "C" */
286 #endif
287
288 #endif /* LV2_EVENT_H */
289
290 /**
291 @}
292 */