cannam@229: cannam@229: /** \mainpage Vamp Plugin SDK cannam@229: cannam@229: \section about About Vamp cannam@229: cannam@229: Vamp is an API for C and C++ plugins that process sampled audio data cannam@229: to produce descriptive output (measurements or semantic observations). cannam@229: Find more information at http://www.vamp-plugins.org/ . cannam@229: cannam@229: Although the official API for Vamp plugins is defined in C for maximum cannam@229: binary compatibility, we strongly recommend using the provided C++ cannam@229: classes in the SDK to implement your own plugins and hosts. cannam@229: cannam@229: \section plugins For Plugins cannam@229: cannam@229: Plugins should subclass Vamp::Plugin, and then use a cannam@229: Vamp::PluginAdapter to expose the correct C API for the plugin. Read cannam@229: the documentation for Vamp::PluginBase and Vamp::Plugin before cannam@229: starting. cannam@229: cannam@229: Plugins should be compiled and linked into dynamic libraries using the cannam@229: usual convention for your platform, and should link (preferably cannam@229: statically) with -lvamp-sdk. Any number of plugins can reside in a cannam@229: single dynamic library. See plugins.cpp in the example plugins cannam@229: directory for the sort of code that will need to accompany your plugin cannam@229: class or classes, to make it possible for a host to look up your cannam@229: plugins properly. cannam@229: cannam@229: You will also need to ensure that the entry point cannam@229: vampGetPluginDescriptor is properly exported (made public) from your cannam@229: shared library. The method to do this depends on your linker; for cannam@229: example, when using the Windows Visual Studio linker, use the linker cannam@229: flag "/EXPORT:vampGetPluginDescriptor". Exported symbols are the cannam@229: default with most other current platforms' linkers. cannam@229: cannam@229: The following example plugins are provided. You may legally reuse any cannam@229: amount of the code from these examples in any plugins you write, cannam@229: whether proprietary or open-source. cannam@229: cannam@229: - ZeroCrossing calculates the positions and density of zero-crossing cannam@229: points in an audio waveform. cannam@229: cannam@229: - SpectralCentroid calculates the centre of gravity of the frequency cannam@229: domain representation of each block of audio. cannam@229: cannam@229: - AmplitudeFollower is a simple implementation of SuperCollider's cannam@229: amplitude-follower algorithm. cannam@229: cannam@229: - PercussionOnsetDetector estimates the locations of percussive cannam@229: onsets using a simple method described in "Drum Source Separation cannam@229: using Percussive Feature Detection and Spectral Modulation" by Dan cannam@229: Barry, Derry Fitzgerald, Eugene Coyle and Bob Lawlor, ISSC 2005. cannam@229: cannam@229: - FixedTempoEstimator calculates a single bpm value which is an cannam@229: estimate of the tempo of a piece of music that is assumed to be of cannam@229: fixed tempo, using autocorrelation of a frequency domain energy rise cannam@229: metric. It has several outputs that return intermediate results used cannam@229: in the calculation, and may be a useful example of a plugin having cannam@229: several outputs with varying feature structures. cannam@229: cannam@229: \section hosts For Hosts cannam@229: cannam@229: Hosts will normally use a Vamp::PluginHostAdapter to convert each cannam@229: plugin's exposed C API back into a useful Vamp::Plugin C++ object. cannam@229: cannam@229: Starting with version 1.1 of the Vamp SDK, there are several classes cannam@229: in the Vamp::HostExt namespace that aim to make the host's life as cannam@229: easy as possible: cannam@229: cannam@229: - Vamp::HostExt::PluginLoader provides a very simple interface for a cannam@229: host to discover, load, and find out category information about the cannam@229: available plugins. Most "casual" Vamp hosts will probably want to cannam@229: use this class. cannam@229: cannam@229: - Vamp::HostExt::PluginInputDomainAdapter provides a simple means for cannam@229: hosts to handle plugins that expect frequency-domain input, without cannam@229: having to convert the input themselves. cannam@229: cannam@229: - Vamp::HostExt::PluginChannelAdapter provides a simple means for cannam@229: hosts to use plugins that do not necessarily support the same number cannam@229: of audio channels as they have available, without having to apply a cannam@229: channel management / mixdown policy themselves. cannam@229: cannam@229: - Vamp::HostExt::PluginBufferingAdapter (new in version 1.2) provides cannam@229: a means for hosts to avoid having to negotiate the input step and cannam@229: block size, instead permitting the host to use any block size they cannam@229: desire (and a step size equal to it). This is particularly useful cannam@229: for "streaming" hosts that cannot seek backwards in the input audio cannam@229: stream and so would otherwise need to implement an additional buffer cannam@229: to support step sizes smaller than the block size. cannam@229: cannam@229: - Vamp::HostExt::PluginSummarisingAdapter (new in version 2.0) cannam@229: provides summarisation methods such as mean and median averages of cannam@229: output features, for use in any context where an available plugin cannam@229: produces individual values but the result that is actually needed cannam@229: is some sort of aggregate. cannam@229: cannam@229: The PluginLoader class can also use the input domain, channel, and cannam@229: buffering adapters automatically to make these conversions transparent cannam@229: to the host if required. cannam@229: cannam@229: Hosts should link with -lvamp-hostsdk. cannam@229: cannam@229: (The following notes in this section are mostly relevant for cannam@229: developers that are not using the HostExt classes, or that wish to cannam@229: know more about the policy they implement.) cannam@229: cannam@229: The Vamp API does not officially specify how to load plugin libraries cannam@229: or where to find them. However, the SDK does include a function cannam@229: (Vamp::PluginHostAdapter::getPluginPath()) that returns a recommended cannam@229: directory search path that hosts may use for plugin libraries. cannam@229: cannam@229: Our suggestion for a host is to search each directory in this path for cannam@229: .DLL (on Windows), .so (on Linux, Solaris, BSD etc) or .dylib (on cannam@229: OS/X) files, then to load each one and perform a dynamic name lookup cannam@229: on the vampGetPluginDescriptor function to enumerate the plugins in cannam@229: the library. The example host has some code that may help, but this cannam@229: operation will necessarily be system-dependent. cannam@229: cannam@229: Vamp also has an informal convention for sorting plugins into cannam@229: functional categories. In addition to the library file itself, a cannam@229: plugin library may install a category file with the same name as the cannam@229: library but .cat extension. The existence and format of this file are cannam@229: not specified by the Vamp API, but by convention the file may contain cannam@229: lines of the format cannam@229: cannam@229: \code cannam@229: vamp:pluginlibrary:pluginname::General Category > Specific Category cannam@229: \endcode cannam@229: cannam@229: which a host may read and use to assign plugins a location within a cannam@229: category tree for display to the user. The expectation is that cannam@229: advanced users may also choose to set up their own preferred category cannam@229: trees, which is why this information is not queried as part of the cannam@229: Vamp API itself. cannam@229: cannam@229: There is an example host in the "host" directory from which code may cannam@229: be drawn. cannam@229: cannam@229: \section license License cannam@229: cannam@229: This plugin SDK is freely redistributable under a "new-style BSD" cannam@229: licence. See the file COPYING for more details. In short, you may cannam@229: modify and redistribute the SDK and example plugins within any cannam@229: commercial or non-commercial, proprietary or open-source plugin or cannam@229: application under almost any conditions, with no obligation to provide cannam@229: source code, provided you retain the original copyright note. cannam@229: cannam@229: cannam@229: */