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Diffstat (limited to 'include/lv2.h')
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diff --git a/include/lv2.h b/include/lv2.h deleted file mode 100644 index e38e2ac..0000000 --- a/include/lv2.h +++ /dev/null @@ -1,321 +0,0 @@ -/* LV2 - LADSPA (Linux Audio Developer's Simple Plugin API) Version 2.0 - * *** PROVISIONAL *** - * - * Copyright (C) 2000-2002 Richard W.E. Furse, Paul Barton-Davis, Stefan - * Westerfeld - * Copyright (C) 2006 Steve Harris, Dave Robillard. - * - * This header is free software; you can redistribute it and/or modify it - * under the terms of the GNU Lesser General Public License as published - * by the Free Software Foundation; either version 2.1 of the License, - * or (at your option) any later version. - * - * This header is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * Lesser General Public License for more details. - * - * You should have received a copy of the GNU Lesser General Public - * License along with this library; if not, write to the Free Software - * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 - * USA. - */ - -#ifndef LV2_H_INCLUDED -#define LV2_H_INCLUDED - -#include <stdint.h> - -#ifdef __cplusplus -extern "C" { -#endif - - -/* ************************************************************************* */ - - -/* Overview: - * - * There are a large number of open source and free software synthesis - * packages in use or development at this time. This API ('LV2') - * attempts to give programmers the ability to write simple 'plugin' - * audio processors in C/C++ and link them dynamically ('plug') into - * a range of these packages ('hosts'). It should be possible for any - * host and any plugin to communicate completely through this interface. - * - * This API is deliberately as short and simple as possible. - * The information required to use a plugin is in a companion data - * (RDF) file. The shared library portion of the API (defined in this - * header) does not contain enough information to make use of the plugin - * possible - the data file is mandatory. - * - * Plugins are expected to distinguish between control rate and audio - * rate data. Plugins have 'ports' that are inputs or outputs for audio - * or control data and each plugin is 'run' for a 'block' corresponding - * to a short time interval measured in samples. Audio rate data is - * communicated using arrays with one element per sample processed, - * allowing a block of audio to be processed by the plugin in a single - * pass. Control rate data is communicated using single values. Control - * rate data has a single value at the start of a call to the 'run()' - * function, and may be considered to remain this value for its duration. - * Thus the 'control rate' is determined by the block size, controlled - * by the host. The plugin may assume that all its input and output - * ports have been connected to the relevant data location (see the - * 'connect_port()' function below) before it is asked to run. - * - * Plugins will reside in shared object files suitable for dynamic linking - * by dlopen() and family. The file will provide a number of 'plugin - * types' that can be used to instantiate actual plugins (sometimes known - * as 'plugin instances') that can be connected together to perform tasks. - * - * This API contains very limited error-handling. - */ - - -/* ************************************************************************* */ - - -/** Plugin Handle. - * - * This plugin handle indicates a particular instance of the plugin - * concerned. It is valid to compare this to NULL (0 for C++) but - * otherwise the host MUST not attempt to interpret it. The plugin - * may use it to reference internal instance data. */ -typedef void * LV2_Handle; - - -/* ************************************************************************* */ - - -/** Host feature. - * - * These are passed to a plugin's instantiate method to represent a special - * feature the host has which the plugin may depend on. This is to allow - * extensions to the LV2 specification without causing any breakage. The base - * LV2 specification does not define any host features; hosts are not required - * to use this facility. - */ -typedef struct _LV2_Host_Feature { - /** A globally unique, case-sensitive identifier for this feature. - * - * This MUST be defined in the specification of any LV2 extension which - * defines a host feature. - */ - const char * URI; - - /** Pointer to arbitrary data. - * - * This is to allow hosts to pass data to a plugin (simple values, data - * structures, function pointers, etc) as part of a 'feature'. The LV2 - * specification makes no restrictions on the contents of this data. - * The data here MUST be cleary defined by the LV2 extension which defines - * this feature. - * If no data is required, this may be set to NULL. - */ - void * data; -} LV2_Host_Feature; - - -/* ************************************************************************* */ - - -/** Descriptor for a Type of Plugin. - * - * This structure is used to describe a plugin type. It provides a number - * of functions to instantiate it, link it to buffers and run it. */ -typedef struct _LV2_Descriptor { - - /** A globally unique, case-sensitive identifier for this plugin type. - * - * All plugins with the same URI MUST be compatible in terms of 'port - * signature', meaning they have the same number of ports, same port - * shortnames, and roughly the same functionality. URIs should - * probably contain a version number (or similar) for this reason. - * - * Rationale: When serializing session/patch/etc files, hosts MUST - * refer to a loaded plugin by the plugin URI only. In the future - * loading a plugin with this URI MUST yield a plugin with the - * same ports (etc) which is 100% compatible. */ - const char * URI; - - /** Function pointer that instantiates a plugin. - * - * A handle is returned indicating the new plugin instance. The - * instantiation function accepts a sample rate as a parameter as well - * as the plugin descriptor from which this instantiate function was - * found. This function must return NULL if instantiation fails. - * - * BundlePath is a string of the path to the plugin's .lv2 bundle - * directory, it MUST not include the trailing /. - * - * HostFeatures is a NULL terminated array of the URIs of the LV2 - * features that the host supports. Plugins may refuse to instantiate - * if required features are not found here (however hosts SHOULD NOT use - * this as a discovery mechanism, instead reading the data file before - * attempting to instantiate the plugin). - * - * Note that instance initialisation should generally occur in - * activate() rather than here. If a host calls instantiate, it MUST - * call cleanup() at some point in the future. */ - LV2_Handle (*instantiate)(const struct _LV2_Descriptor * Descriptor, - uint32_t SampleRate, - const char * BundlePath, - const LV2_Host_Feature** HostFeatures); - - /** Function pointer that connects a port on a plugin instance to a memory - * location where the block of data for the port will be read/written. - * - * The data location is expected to be an array of void * (typically - * float *) for audio ports or a single void * value for control - * ports. Memory issues are managed by the host. The plugin must - * read/write the data at these locations every time run() is called - * and the data present at the time of this connection call MUST NOT - * be considered meaningful. - * - * connect_port() may be called more than once for a plugin instance - * to allow the host to change the buffers that the plugin is reading - * or writing. These calls may be made before or after activate() - * or deactivate() calls. - * - * connect_port() must be called at least once for each port before - * run() is called. The plugin must pay careful attention to the block - * size passed to the run function as the block allocated may only just - * be large enough to contain the block of data (typically samples), and - * is not guaranteed to be constant. - * - * Plugin writers should be aware that the host may elect to use the - * same buffer for more than one port and even use the same buffer for - * both input and output (see LV2_PROPERTY_INPLACE_BROKEN (FIXME)). - * However, overlapped buffers or use of a single buffer for both - * audio and control data may result in unexpected behaviour. */ - void (*connect_port)(LV2_Handle Instance, - uint32_t Port, - void * DataLocation); - - /** Function pointer that initialises a plugin instance and activates - * it for use. - * - * This is separated from instantiate() to aid real-time support and so - * that hosts can reinitialise a plugin instance by calling deactivate() - * and then activate(). In this case the plugin instance must reset all - * state information dependent on the history of the plugin instance - * except for any data locations provided by connect_port(). If there - * is nothing for activate() to do then the plugin writer may provide - * a NULL rather than an empty function. - * - * When present, hosts MUST call this function once before run() - * is called for the first time. This call SHOULD be made as close - * to the run() call as possible and indicates to real-time plugins - * that they are now live, however plugins MUST NOT rely on a prompt - * call to run() after activate(). activate() may not be called again - * unless deactivate() is called first (after which activate() may be - * called again, followed by deactivate, etc. etc.). If a host calls - * activate, it MUST call deactivate at some point in the future. - * - * Note that connect_port() may be called before or after a call to - * activate(). */ - void (*activate)(LV2_Handle Instance); - - /** Function pointer that runs a plugin instance for a block. - * - * Two parameters are required: the first is a handle to the particular - * instance to be run and the second indicates the block size (in - * samples) for which the plugin instance may run. - * - * Note that if an activate() function exists then it must be called - * before run(). If deactivate() is called for a plugin instance then - * the plugin instance may not be reused until activate() has been - * called again. - * - * If the plugin has the property LV2_PROPERTY_HARD_RT_CAPABLE then - * there are various things that the plugin MUST NOT do within the run() - * function (see above). */ - void (*run)(LV2_Handle Instance, - uint32_t SampleCount); - - /** This is the counterpart to activate() (see above). If there is - * nothing for deactivate() to do then the plugin writer may provide - * a NULL rather than an empty function. - * - * Hosts must deactivate all activated units after they have been run() - * for the last time. This call SHOULD be made as close to the last - * run() call as possible and indicates to real-time plugins that - * they are no longer live, however plugins MUST NOT rely on prompt - * deactivation. Note that connect_port() may be called before or - * after a call to deactivate(). - * - * Note that deactivation is not similar to pausing as the plugin - * instance will be reinitialised when activate() is called to reuse it. - * Hosts MUST NOT call deactivate() unless activate() was previously - * called. */ - void (*deactivate)(LV2_Handle Instance); - - /** This is the counterpart to instantiate() (see above). Once an instance - * of a plugin has been finished with it can be deleted using this - * function. The instance handle passed ceases to be valid after - * this call. - * - * If activate() was called for a plugin instance then a corresponding - * call to deactivate() MUST be made before cleanup() is called. - * Hosts MUST NOT call cleanup() unless instantiate() was previously - * called. */ - void (*cleanup)(LV2_Handle Instance); - -} LV2_Descriptor; - - -/* ****************************************************************** */ - - -/** Accessing a Plugin: - * - * The exact mechanism by which plugins are loaded is host-dependent, - * however all most hosts will need to know is the URI of the plugin they - * wish to load. The environment variable LV2_PATH, if present, should - * contain a colon-separated path indicating directories (containing - * plugin bundle subdirectories) that should be searched (in order) - * for plugins. It is expected that hosts will use a library to provide - * this functionality. - * - * A plugin programmer must include a function called "lv2_descriptor" - * with the following function prototype within the shared object - * file. This function will have C-style linkage (if you are using - * C++ this is taken care of by the 'extern "C"' clause at the top of - * the file). - * - * A host will find the plugin shared object file by one means or another, - * find the lv2_descriptor() function, call it, and proceed from there. - * - * Plugin types are accessed by index (not ID) using values from 0 - * upwards. Out of range indexes must result in this function returning - * NULL, so the plugin count can be determined by checking for the least - * index that results in NULL being returned. Index has no meaning, - * hosts MUST NOT depend on it remaining constant (ie when serialising) - * in any way. */ -const LV2_Descriptor * lv2_descriptor(uint32_t Index); - - -/** Datatype corresponding to the lv2_descriptor() function. */ -typedef const LV2_Descriptor * -(*LV2_Descriptor_Function)(uint32_t Index); - - -/* ******************************************************************** */ - - -/* Put this (LV2_SYMBOL_EXPORT) before any functions that are to be loaded - * by the host as a symbol from the dynamic library. - */ -#ifdef WIN32 -#define LV2_SYMBOL_EXPORT __declspec(dllexport) -#else -#define LV2_SYMBOL_EXPORT -#endif - - -#ifdef __cplusplus -} -#endif - -#endif /* LV2_H_INCLUDED */ - |