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comparison DPF-Prymula-audioplugins/dpf/distrho/src/ladspa/ladspa.h @ 3:84e66ea83026
DPF-Prymula-audioplugins-0.231015-2
author | prymula <prymula76@outlook.com> |
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date | Mon, 16 Oct 2023 21:53:34 +0200 |
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1 /* ladspa.h | |
2 | |
3 Linux Audio Developer's Simple Plugin API Version 1.1[LGPL]. | |
4 Copyright (C) 2000-2002 Richard W.E. Furse, Paul Barton-Davis, | |
5 Stefan Westerfeld. | |
6 | |
7 This library is free software; you can redistribute it and/or | |
8 modify it under the terms of the GNU Lesser General Public License | |
9 as published by the Free Software Foundation; either version 2.1 of | |
10 the License, or (at your option) any later version. | |
11 | |
12 This library is distributed in the hope that it will be useful, but | |
13 WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 Lesser General Public License for more details. | |
16 | |
17 You should have received a copy of the GNU Lesser General Public | |
18 License along with this library; if not, write to the Free Software | |
19 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 | |
20 USA. */ | |
21 | |
22 #ifndef LADSPA_INCLUDED | |
23 #define LADSPA_INCLUDED | |
24 | |
25 #define LADSPA_VERSION "1.1" | |
26 #define LADSPA_VERSION_MAJOR 1 | |
27 #define LADSPA_VERSION_MINOR 1 | |
28 | |
29 #ifdef __cplusplus | |
30 extern "C" { | |
31 #endif | |
32 | |
33 #ifndef LADSPA_PLUGIN_EXPORT | |
34 # ifdef _WIN32 | |
35 # define LADSPA_PLUGIN_EXPORT __declspec(dllexport) | |
36 # else | |
37 # define LADSPA_PLUGIN_EXPORT __attribute__((visibility("default"))) | |
38 # endif | |
39 #endif | |
40 | |
41 /*****************************************************************************/ | |
42 | |
43 /* Overview: | |
44 | |
45 There is a large number of synthesis packages in use or development | |
46 on the Linux platform at this time. This API (`The Linux Audio | |
47 Developer's Simple Plugin API') attempts to give programmers the | |
48 ability to write simple `plugin' audio processors in C/C++ and link | |
49 them dynamically (`plug') into a range of these packages (`hosts'). | |
50 It should be possible for any host and any plugin to communicate | |
51 completely through this interface. | |
52 | |
53 This API is deliberately short and simple. To achieve compatibility | |
54 with a range of promising Linux sound synthesis packages it | |
55 attempts to find the `greatest common divisor' in their logical | |
56 behaviour. Having said this, certain limiting decisions are | |
57 implicit, notably the use of a fixed type (LADSPA_Data) for all | |
58 data transfer and absence of a parameterised `initialisation' | |
59 phase. See below for the LADSPA_Data typedef. | |
60 | |
61 Plugins are expected to distinguish between control and audio | |
62 data. Plugins have `ports' that are inputs or outputs for audio or | |
63 control data and each plugin is `run' for a `block' corresponding | |
64 to a short time interval measured in samples. Audio data is | |
65 communicated using arrays of LADSPA_Data, allowing a block of audio | |
66 to be processed by the plugin in a single pass. Control data is | |
67 communicated using single LADSPA_Data values. Control data has a | |
68 single value at the start of a call to the `run()' or `run_adding()' | |
69 function, and may be considered to remain this value for its | |
70 duration. The plugin may assume that all its input and output ports | |
71 have been connected to the relevant data location (see the | |
72 `connect_port()' function below) before it is asked to run. | |
73 | |
74 Plugins will reside in shared object files suitable for dynamic | |
75 linking by dlopen() and family. The file will provide a number of | |
76 `plugin types' that can be used to instantiate actual plugins | |
77 (sometimes known as `plugin instances') that can be connected | |
78 together to perform tasks. | |
79 | |
80 This API contains very limited error-handling. */ | |
81 | |
82 /*****************************************************************************/ | |
83 | |
84 /* Fundamental data type passed in and out of plugin. This data type | |
85 is used to communicate audio samples and control values. It is | |
86 assumed that the plugin will work sensibly given any numeric input | |
87 value although it may have a preferred range (see hints below). | |
88 | |
89 For audio it is generally assumed that 1.0f is the `0dB' reference | |
90 amplitude and is a `normal' signal level. */ | |
91 | |
92 typedef float LADSPA_Data; | |
93 | |
94 /*****************************************************************************/ | |
95 | |
96 /* Special Plugin Properties: | |
97 | |
98 Optional features of the plugin type are encapsulated in the | |
99 LADSPA_Properties type. This is assembled by ORing individual | |
100 properties together. */ | |
101 | |
102 typedef int LADSPA_Properties; | |
103 | |
104 /* Property LADSPA_PROPERTY_REALTIME indicates that the plugin has a | |
105 real-time dependency (e.g. listens to a MIDI device) and so its | |
106 output must not be cached or subject to significant latency. */ | |
107 #define LADSPA_PROPERTY_REALTIME 0x1 | |
108 | |
109 /* Property LADSPA_PROPERTY_INPLACE_BROKEN indicates that the plugin | |
110 may cease to work correctly if the host elects to use the same data | |
111 location for both input and output (see connect_port()). This | |
112 should be avoided as enabling this flag makes it impossible for | |
113 hosts to use the plugin to process audio `in-place.' */ | |
114 #define LADSPA_PROPERTY_INPLACE_BROKEN 0x2 | |
115 | |
116 /* Property LADSPA_PROPERTY_HARD_RT_CAPABLE indicates that the plugin | |
117 is capable of running not only in a conventional host but also in a | |
118 `hard real-time' environment. To qualify for this the plugin must | |
119 satisfy all of the following: | |
120 | |
121 (1) The plugin must not use malloc(), free() or other heap memory | |
122 management within its run() or run_adding() functions. All new | |
123 memory used in run() must be managed via the stack. These | |
124 restrictions only apply to the run() function. | |
125 | |
126 (2) The plugin will not attempt to make use of any library | |
127 functions with the exceptions of functions in the ANSI standard C | |
128 and C maths libraries, which the host is expected to provide. | |
129 | |
130 (3) The plugin will not access files, devices, pipes, sockets, IPC | |
131 or any other mechanism that might result in process or thread | |
132 blocking. | |
133 | |
134 (4) The plugin will take an amount of time to execute a run() or | |
135 run_adding() call approximately of form (A+B*SampleCount) where A | |
136 and B depend on the machine and host in use. This amount of time | |
137 may not depend on input signals or plugin state. The host is left | |
138 the responsibility to perform timings to estimate upper bounds for | |
139 A and B. */ | |
140 #define LADSPA_PROPERTY_HARD_RT_CAPABLE 0x4 | |
141 | |
142 #define LADSPA_IS_REALTIME(x) ((x) & LADSPA_PROPERTY_REALTIME) | |
143 #define LADSPA_IS_INPLACE_BROKEN(x) ((x) & LADSPA_PROPERTY_INPLACE_BROKEN) | |
144 #define LADSPA_IS_HARD_RT_CAPABLE(x) ((x) & LADSPA_PROPERTY_HARD_RT_CAPABLE) | |
145 | |
146 /*****************************************************************************/ | |
147 | |
148 /* Plugin Ports: | |
149 | |
150 Plugins have `ports' that are inputs or outputs for audio or | |
151 data. Ports can communicate arrays of LADSPA_Data (for audio | |
152 inputs/outputs) or single LADSPA_Data values (for control | |
153 input/outputs). This information is encapsulated in the | |
154 LADSPA_PortDescriptor type which is assembled by ORing individual | |
155 properties together. | |
156 | |
157 Note that a port must be an input or an output port but not both | |
158 and that a port must be a control or audio port but not both. */ | |
159 | |
160 typedef int LADSPA_PortDescriptor; | |
161 | |
162 /* Property LADSPA_PORT_INPUT indicates that the port is an input. */ | |
163 #define LADSPA_PORT_INPUT 0x1 | |
164 | |
165 /* Property LADSPA_PORT_OUTPUT indicates that the port is an output. */ | |
166 #define LADSPA_PORT_OUTPUT 0x2 | |
167 | |
168 /* Property LADSPA_PORT_CONTROL indicates that the port is a control | |
169 port. */ | |
170 #define LADSPA_PORT_CONTROL 0x4 | |
171 | |
172 /* Property LADSPA_PORT_AUDIO indicates that the port is a audio | |
173 port. */ | |
174 #define LADSPA_PORT_AUDIO 0x8 | |
175 | |
176 #define LADSPA_IS_PORT_INPUT(x) ((x) & LADSPA_PORT_INPUT) | |
177 #define LADSPA_IS_PORT_OUTPUT(x) ((x) & LADSPA_PORT_OUTPUT) | |
178 #define LADSPA_IS_PORT_CONTROL(x) ((x) & LADSPA_PORT_CONTROL) | |
179 #define LADSPA_IS_PORT_AUDIO(x) ((x) & LADSPA_PORT_AUDIO) | |
180 | |
181 /*****************************************************************************/ | |
182 | |
183 /* Plugin Port Range Hints: | |
184 | |
185 The host may wish to provide a representation of data entering or | |
186 leaving a plugin (e.g. to generate a GUI automatically). To make | |
187 this more meaningful, the plugin should provide `hints' to the host | |
188 describing the usual values taken by the data. | |
189 | |
190 Note that these are only hints. The host may ignore them and the | |
191 plugin must not assume that data supplied to it is meaningful. If | |
192 the plugin receives invalid input data it is expected to continue | |
193 to run without failure and, where possible, produce a sensible | |
194 output (e.g. a high-pass filter given a negative cutoff frequency | |
195 might switch to an all-pass mode). | |
196 | |
197 Hints are meaningful for all input and output ports but hints for | |
198 input control ports are expected to be particularly useful. | |
199 | |
200 More hint information is encapsulated in the | |
201 LADSPA_PortRangeHintDescriptor type which is assembled by ORing | |
202 individual hint types together. Hints may require further | |
203 LowerBound and UpperBound information. | |
204 | |
205 All the hint information for a particular port is aggregated in the | |
206 LADSPA_PortRangeHint structure. */ | |
207 | |
208 typedef int LADSPA_PortRangeHintDescriptor; | |
209 | |
210 /* Hint LADSPA_HINT_BOUNDED_BELOW indicates that the LowerBound field | |
211 of the LADSPA_PortRangeHint should be considered meaningful. The | |
212 value in this field should be considered the (inclusive) lower | |
213 bound of the valid range. If LADSPA_HINT_SAMPLE_RATE is also | |
214 specified then the value of LowerBound should be multiplied by the | |
215 sample rate. */ | |
216 #define LADSPA_HINT_BOUNDED_BELOW 0x1 | |
217 | |
218 /* Hint LADSPA_HINT_BOUNDED_ABOVE indicates that the UpperBound field | |
219 of the LADSPA_PortRangeHint should be considered meaningful. The | |
220 value in this field should be considered the (inclusive) upper | |
221 bound of the valid range. If LADSPA_HINT_SAMPLE_RATE is also | |
222 specified then the value of UpperBound should be multiplied by the | |
223 sample rate. */ | |
224 #define LADSPA_HINT_BOUNDED_ABOVE 0x2 | |
225 | |
226 /* Hint LADSPA_HINT_TOGGLED indicates that the data item should be | |
227 considered a Boolean toggle. Data less than or equal to zero should | |
228 be considered `off' or `false,' and data above zero should be | |
229 considered `on' or `true.' LADSPA_HINT_TOGGLED may not be used in | |
230 conjunction with any other hint except LADSPA_HINT_DEFAULT_0 or | |
231 LADSPA_HINT_DEFAULT_1. */ | |
232 #define LADSPA_HINT_TOGGLED 0x4 | |
233 | |
234 /* Hint LADSPA_HINT_SAMPLE_RATE indicates that any bounds specified | |
235 should be interpreted as multiples of the sample rate. For | |
236 instance, a frequency range from 0Hz to the Nyquist frequency (half | |
237 the sample rate) could be requested by this hint in conjunction | |
238 with LowerBound = 0 and UpperBound = 0.5. Hosts that support bounds | |
239 at all must support this hint to retain meaning. */ | |
240 #define LADSPA_HINT_SAMPLE_RATE 0x8 | |
241 | |
242 /* Hint LADSPA_HINT_LOGARITHMIC indicates that it is likely that the | |
243 user will find it more intuitive to view values using a logarithmic | |
244 scale. This is particularly useful for frequencies and gains. */ | |
245 #define LADSPA_HINT_LOGARITHMIC 0x10 | |
246 | |
247 /* Hint LADSPA_HINT_INTEGER indicates that a user interface would | |
248 probably wish to provide a stepped control taking only integer | |
249 values. Any bounds set should be slightly wider than the actual | |
250 integer range required to avoid floating point rounding errors. For | |
251 instance, the integer set {0,1,2,3} might be described as [-0.1, | |
252 3.1]. */ | |
253 #define LADSPA_HINT_INTEGER 0x20 | |
254 | |
255 /* The various LADSPA_HINT_HAS_DEFAULT_* hints indicate a `normal' | |
256 value for the port that is sensible as a default. For instance, | |
257 this value is suitable for use as an initial value in a user | |
258 interface or as a value the host might assign to a control port | |
259 when the user has not provided one. Defaults are encoded using a | |
260 mask so only one default may be specified for a port. Some of the | |
261 hints make use of lower and upper bounds, in which case the | |
262 relevant bound or bounds must be available and | |
263 LADSPA_HINT_SAMPLE_RATE must be applied as usual. The resulting | |
264 default must be rounded if LADSPA_HINT_INTEGER is present. Default | |
265 values were introduced in LADSPA v1.1. */ | |
266 #define LADSPA_HINT_DEFAULT_MASK 0x3C0 | |
267 | |
268 /* This default values indicates that no default is provided. */ | |
269 #define LADSPA_HINT_DEFAULT_NONE 0x0 | |
270 | |
271 /* This default hint indicates that the suggested lower bound for the | |
272 port should be used. */ | |
273 #define LADSPA_HINT_DEFAULT_MINIMUM 0x40 | |
274 | |
275 /* This default hint indicates that a low value between the suggested | |
276 lower and upper bounds should be chosen. For ports with | |
277 LADSPA_HINT_LOGARITHMIC, this should be exp(log(lower) * 0.75 + | |
278 log(upper) * 0.25). Otherwise, this should be (lower * 0.75 + upper | |
279 * 0.25). */ | |
280 #define LADSPA_HINT_DEFAULT_LOW 0x80 | |
281 | |
282 /* This default hint indicates that a middle value between the | |
283 suggested lower and upper bounds should be chosen. For ports with | |
284 LADSPA_HINT_LOGARITHMIC, this should be exp(log(lower) * 0.5 + | |
285 log(upper) * 0.5). Otherwise, this should be (lower * 0.5 + upper * | |
286 0.5). */ | |
287 #define LADSPA_HINT_DEFAULT_MIDDLE 0xC0 | |
288 | |
289 /* This default hint indicates that a high value between the suggested | |
290 lower and upper bounds should be chosen. For ports with | |
291 LADSPA_HINT_LOGARITHMIC, this should be exp(log(lower) * 0.25 + | |
292 log(upper) * 0.75). Otherwise, this should be (lower * 0.25 + upper | |
293 * 0.75). */ | |
294 #define LADSPA_HINT_DEFAULT_HIGH 0x100 | |
295 | |
296 /* This default hint indicates that the suggested upper bound for the | |
297 port should be used. */ | |
298 #define LADSPA_HINT_DEFAULT_MAXIMUM 0x140 | |
299 | |
300 /* This default hint indicates that the number 0 should be used. Note | |
301 that this default may be used in conjunction with | |
302 LADSPA_HINT_TOGGLED. */ | |
303 #define LADSPA_HINT_DEFAULT_0 0x200 | |
304 | |
305 /* This default hint indicates that the number 1 should be used. Note | |
306 that this default may be used in conjunction with | |
307 LADSPA_HINT_TOGGLED. */ | |
308 #define LADSPA_HINT_DEFAULT_1 0x240 | |
309 | |
310 /* This default hint indicates that the number 100 should be used. */ | |
311 #define LADSPA_HINT_DEFAULT_100 0x280 | |
312 | |
313 /* This default hint indicates that the Hz frequency of `concert A' | |
314 should be used. This will be 440 unless the host uses an unusual | |
315 tuning convention, in which case it may be within a few Hz. */ | |
316 #define LADSPA_HINT_DEFAULT_440 0x2C0 | |
317 | |
318 #define LADSPA_IS_HINT_BOUNDED_BELOW(x) ((x) & LADSPA_HINT_BOUNDED_BELOW) | |
319 #define LADSPA_IS_HINT_BOUNDED_ABOVE(x) ((x) & LADSPA_HINT_BOUNDED_ABOVE) | |
320 #define LADSPA_IS_HINT_TOGGLED(x) ((x) & LADSPA_HINT_TOGGLED) | |
321 #define LADSPA_IS_HINT_SAMPLE_RATE(x) ((x) & LADSPA_HINT_SAMPLE_RATE) | |
322 #define LADSPA_IS_HINT_LOGARITHMIC(x) ((x) & LADSPA_HINT_LOGARITHMIC) | |
323 #define LADSPA_IS_HINT_INTEGER(x) ((x) & LADSPA_HINT_INTEGER) | |
324 | |
325 #define LADSPA_IS_HINT_HAS_DEFAULT(x) ((x) & LADSPA_HINT_DEFAULT_MASK) | |
326 #define LADSPA_IS_HINT_DEFAULT_MINIMUM(x) (((x) & LADSPA_HINT_DEFAULT_MASK) \ | |
327 == LADSPA_HINT_DEFAULT_MINIMUM) | |
328 #define LADSPA_IS_HINT_DEFAULT_LOW(x) (((x) & LADSPA_HINT_DEFAULT_MASK) \ | |
329 == LADSPA_HINT_DEFAULT_LOW) | |
330 #define LADSPA_IS_HINT_DEFAULT_MIDDLE(x) (((x) & LADSPA_HINT_DEFAULT_MASK) \ | |
331 == LADSPA_HINT_DEFAULT_MIDDLE) | |
332 #define LADSPA_IS_HINT_DEFAULT_HIGH(x) (((x) & LADSPA_HINT_DEFAULT_MASK) \ | |
333 == LADSPA_HINT_DEFAULT_HIGH) | |
334 #define LADSPA_IS_HINT_DEFAULT_MAXIMUM(x) (((x) & LADSPA_HINT_DEFAULT_MASK) \ | |
335 == LADSPA_HINT_DEFAULT_MAXIMUM) | |
336 #define LADSPA_IS_HINT_DEFAULT_0(x) (((x) & LADSPA_HINT_DEFAULT_MASK) \ | |
337 == LADSPA_HINT_DEFAULT_0) | |
338 #define LADSPA_IS_HINT_DEFAULT_1(x) (((x) & LADSPA_HINT_DEFAULT_MASK) \ | |
339 == LADSPA_HINT_DEFAULT_1) | |
340 #define LADSPA_IS_HINT_DEFAULT_100(x) (((x) & LADSPA_HINT_DEFAULT_MASK) \ | |
341 == LADSPA_HINT_DEFAULT_100) | |
342 #define LADSPA_IS_HINT_DEFAULT_440(x) (((x) & LADSPA_HINT_DEFAULT_MASK) \ | |
343 == LADSPA_HINT_DEFAULT_440) | |
344 | |
345 typedef struct _LADSPA_PortRangeHint { | |
346 | |
347 /* Hints about the port. */ | |
348 LADSPA_PortRangeHintDescriptor HintDescriptor; | |
349 | |
350 /* Meaningful when hint LADSPA_HINT_BOUNDED_BELOW is active. When | |
351 LADSPA_HINT_SAMPLE_RATE is also active then this value should be | |
352 multiplied by the relevant sample rate. */ | |
353 LADSPA_Data LowerBound; | |
354 | |
355 /* Meaningful when hint LADSPA_HINT_BOUNDED_ABOVE is active. When | |
356 LADSPA_HINT_SAMPLE_RATE is also active then this value should be | |
357 multiplied by the relevant sample rate. */ | |
358 LADSPA_Data UpperBound; | |
359 | |
360 } LADSPA_PortRangeHint; | |
361 | |
362 /*****************************************************************************/ | |
363 | |
364 /* Plugin Handles: | |
365 | |
366 This plugin handle indicates a particular instance of the plugin | |
367 concerned. It is valid to compare this to NULL (0 for C++) but | |
368 otherwise the host should not attempt to interpret it. The plugin | |
369 may use it to reference internal instance data. */ | |
370 | |
371 typedef void * LADSPA_Handle; | |
372 | |
373 /*****************************************************************************/ | |
374 | |
375 /* Descriptor for a Type of Plugin: | |
376 | |
377 This structure is used to describe a plugin type. It provides a | |
378 number of functions to examine the type, instantiate it, link it to | |
379 buffers and workspaces and to run it. */ | |
380 | |
381 typedef struct _LADSPA_Descriptor { | |
382 | |
383 /* This numeric identifier indicates the plugin type | |
384 uniquely. Plugin programmers may reserve ranges of IDs from a | |
385 central body to avoid clashes. Hosts may assume that IDs are | |
386 below 0x1000000. */ | |
387 unsigned long UniqueID; | |
388 | |
389 /* This identifier can be used as a unique, case-sensitive | |
390 identifier for the plugin type within the plugin file. Plugin | |
391 types should be identified by file and label rather than by index | |
392 or plugin name, which may be changed in new plugin | |
393 versions. Labels must not contain white-space characters. */ | |
394 const char * Label; | |
395 | |
396 /* This indicates a number of properties of the plugin. */ | |
397 LADSPA_Properties Properties; | |
398 | |
399 /* This member points to the null-terminated name of the plugin | |
400 (e.g. "Sine Oscillator"). */ | |
401 const char * Name; | |
402 | |
403 /* This member points to the null-terminated string indicating the | |
404 maker of the plugin. This can be an empty string but not NULL. */ | |
405 const char * Maker; | |
406 | |
407 /* This member points to the null-terminated string indicating any | |
408 copyright applying to the plugin. If no Copyright applies the | |
409 string "None" should be used. */ | |
410 const char * Copyright; | |
411 | |
412 /* This indicates the number of ports (input AND output) present on | |
413 the plugin. */ | |
414 unsigned long PortCount; | |
415 | |
416 /* This member indicates an array of port descriptors. Valid indices | |
417 vary from 0 to PortCount-1. */ | |
418 const LADSPA_PortDescriptor * PortDescriptors; | |
419 | |
420 /* This member indicates an array of null-terminated strings | |
421 describing ports (e.g. "Frequency (Hz)"). Valid indices vary from | |
422 0 to PortCount-1. */ | |
423 const char * const * PortNames; | |
424 | |
425 /* This member indicates an array of range hints for each port (see | |
426 above). Valid indices vary from 0 to PortCount-1. */ | |
427 const LADSPA_PortRangeHint * PortRangeHints; | |
428 | |
429 /* This may be used by the plugin developer to pass any custom | |
430 implementation data into an instantiate call. It must not be used | |
431 or interpreted by the host. It is expected that most plugin | |
432 writers will not use this facility as LADSPA_Handle should be | |
433 used to hold instance data. */ | |
434 void * ImplementationData; | |
435 | |
436 /* This member is a function pointer that instantiates a plugin. A | |
437 handle is returned indicating the new plugin instance. The | |
438 instantiation function accepts a sample rate as a parameter. The | |
439 plugin descriptor from which this instantiate function was found | |
440 must also be passed. This function must return NULL if | |
441 instantiation fails. | |
442 | |
443 Note that instance initialisation should generally occur in | |
444 activate() rather than here. */ | |
445 LADSPA_Handle (*instantiate)(const struct _LADSPA_Descriptor * Descriptor, | |
446 unsigned long SampleRate); | |
447 | |
448 /* This member is a function pointer that connects a port on an | |
449 instantiated plugin to a memory location at which a block of data | |
450 for the port will be read/written. The data location is expected | |
451 to be an array of LADSPA_Data for audio ports or a single | |
452 LADSPA_Data value for control ports. Memory issues will be | |
453 managed by the host. The plugin must read/write the data at these | |
454 locations every time run() or run_adding() is called and the data | |
455 present at the time of this connection call should not be | |
456 considered meaningful. | |
457 | |
458 connect_port() may be called more than once for a plugin instance | |
459 to allow the host to change the buffers that the plugin is | |
460 reading or writing. These calls may be made before or after | |
461 activate() or deactivate() calls. | |
462 | |
463 connect_port() must be called at least once for each port before | |
464 run() or run_adding() is called. When working with blocks of | |
465 LADSPA_Data the plugin should pay careful attention to the block | |
466 size passed to the run function as the block allocated may only | |
467 just be large enough to contain the block of samples. | |
468 | |
469 Plugin writers should be aware that the host may elect to use the | |
470 same buffer for more than one port and even use the same buffer | |
471 for both input and output (see LADSPA_PROPERTY_INPLACE_BROKEN). | |
472 However, overlapped buffers or use of a single buffer for both | |
473 audio and control data may result in unexpected behaviour. */ | |
474 void (*connect_port)(LADSPA_Handle Instance, | |
475 unsigned long Port, | |
476 LADSPA_Data * DataLocation); | |
477 | |
478 /* This member is a function pointer that initialises a plugin | |
479 instance and activates it for use. This is separated from | |
480 instantiate() to aid real-time support and so that hosts can | |
481 reinitialise a plugin instance by calling deactivate() and then | |
482 activate(). In this case the plugin instance must reset all state | |
483 information dependent on the history of the plugin instance | |
484 except for any data locations provided by connect_port() and any | |
485 gain set by set_run_adding_gain(). If there is nothing for | |
486 activate() to do then the plugin writer may provide a NULL rather | |
487 than an empty function. | |
488 | |
489 When present, hosts must call this function once before run() (or | |
490 run_adding()) is called for the first time. This call should be | |
491 made as close to the run() call as possible and indicates to | |
492 real-time plugins that they are now live. Plugins should not rely | |
493 on a prompt call to run() after activate(). activate() may not be | |
494 called again unless deactivate() is called first. Note that | |
495 connect_port() may be called before or after a call to | |
496 activate(). */ | |
497 void (*activate)(LADSPA_Handle Instance); | |
498 | |
499 /* This method is a function pointer that runs an instance of a | |
500 plugin for a block. Two parameters are required: the first is a | |
501 handle to the particular instance to be run and the second | |
502 indicates the block size (in samples) for which the plugin | |
503 instance may run. | |
504 | |
505 Note that if an activate() function exists then it must be called | |
506 before run() or run_adding(). If deactivate() is called for a | |
507 plugin instance then the plugin instance may not be reused until | |
508 activate() has been called again. | |
509 | |
510 If the plugin has the property LADSPA_PROPERTY_HARD_RT_CAPABLE | |
511 then there are various things that the plugin should not do | |
512 within the run() or run_adding() functions (see above). */ | |
513 void (*run)(LADSPA_Handle Instance, | |
514 unsigned long SampleCount); | |
515 | |
516 /* This method is a function pointer that runs an instance of a | |
517 plugin for a block. This has identical behaviour to run() except | |
518 in the way data is output from the plugin. When run() is used, | |
519 values are written directly to the memory areas associated with | |
520 the output ports. However when run_adding() is called, values | |
521 must be added to the values already present in the memory | |
522 areas. Furthermore, output values written must be scaled by the | |
523 current gain set by set_run_adding_gain() (see below) before | |
524 addition. | |
525 | |
526 run_adding() is optional. When it is not provided by a plugin, | |
527 this function pointer must be set to NULL. When it is provided, | |
528 the function set_run_adding_gain() must be provided also. */ | |
529 void (*run_adding)(LADSPA_Handle Instance, | |
530 unsigned long SampleCount); | |
531 | |
532 /* This method is a function pointer that sets the output gain for | |
533 use when run_adding() is called (see above). If this function is | |
534 never called the gain is assumed to default to 1. Gain | |
535 information should be retained when activate() or deactivate() | |
536 are called. | |
537 | |
538 This function should be provided by the plugin if and only if the | |
539 run_adding() function is provided. When it is absent this | |
540 function pointer must be set to NULL. */ | |
541 void (*set_run_adding_gain)(LADSPA_Handle Instance, | |
542 LADSPA_Data Gain); | |
543 | |
544 /* This is the counterpart to activate() (see above). If there is | |
545 nothing for deactivate() to do then the plugin writer may provide | |
546 a NULL rather than an empty function. | |
547 | |
548 Hosts must deactivate all activated units after they have been | |
549 run() (or run_adding()) for the last time. This call should be | |
550 made as close to the last run() call as possible and indicates to | |
551 real-time plugins that they are no longer live. Plugins should | |
552 not rely on prompt deactivation. Note that connect_port() may be | |
553 called before or after a call to deactivate(). | |
554 | |
555 Deactivation is not similar to pausing as the plugin instance | |
556 will be reinitialised when activate() is called to reuse it. */ | |
557 void (*deactivate)(LADSPA_Handle Instance); | |
558 | |
559 /* Once an instance of a plugin has been finished with it can be | |
560 deleted using the following function. The instance handle passed | |
561 ceases to be valid after this call. | |
562 | |
563 If activate() was called for a plugin instance then a | |
564 corresponding call to deactivate() must be made before cleanup() | |
565 is called. */ | |
566 void (*cleanup)(LADSPA_Handle Instance); | |
567 | |
568 } LADSPA_Descriptor; | |
569 | |
570 /**********************************************************************/ | |
571 | |
572 /* Accessing a Plugin: */ | |
573 | |
574 /* The exact mechanism by which plugins are loaded is host-dependent, | |
575 however all most hosts will need to know is the name of shared | |
576 object file containing the plugin types. To allow multiple hosts to | |
577 share plugin types, hosts may wish to check for environment | |
578 variable LADSPA_PATH. If present, this should contain a | |
579 colon-separated path indicating directories that should be searched | |
580 (in order) when loading plugin types. | |
581 | |
582 A plugin programmer must include a function called | |
583 "ladspa_descriptor" with the following function prototype within | |
584 the shared object file. This function will have C-style linkage (if | |
585 you are using C++ this is taken care of by the `extern "C"' clause | |
586 at the top of the file). | |
587 | |
588 A host will find the plugin shared object file by one means or | |
589 another, find the ladspa_descriptor() function, call it, and | |
590 proceed from there. | |
591 | |
592 Plugin types are accessed by index (not ID) using values from 0 | |
593 upwards. Out of range indexes must result in this function | |
594 returning NULL, so the plugin count can be determined by checking | |
595 for the least index that results in NULL being returned. */ | |
596 | |
597 LADSPA_PLUGIN_EXPORT const LADSPA_Descriptor * ladspa_descriptor(unsigned long Index); | |
598 | |
599 /* Datatype corresponding to the ladspa_descriptor() function. */ | |
600 typedef const LADSPA_Descriptor * | |
601 (*LADSPA_Descriptor_Function)(unsigned long Index); | |
602 | |
603 /**********************************************************************/ | |
604 | |
605 #ifdef __cplusplus | |
606 } | |
607 #endif | |
608 | |
609 #endif /* LADSPA_INCLUDED */ | |
610 | |
611 /* EOF */ |