cannam@233: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */ cannam@233: cannam@233: /* cannam@233: Vamp cannam@233: cannam@233: An API for audio analysis and feature extraction plugins. cannam@233: cannam@233: Centre for Digital Music, Queen Mary, University of London. cannam@233: Copyright 2006-2007 Chris Cannam and QMUL. cannam@233: cannam@233: Permission is hereby granted, free of charge, to any person cannam@233: obtaining a copy of this software and associated documentation cannam@233: files (the "Software"), to deal in the Software without cannam@233: restriction, including without limitation the rights to use, copy, cannam@233: modify, merge, publish, distribute, sublicense, and/or sell copies cannam@233: of the Software, and to permit persons to whom the Software is cannam@233: furnished to do so, subject to the following conditions: cannam@233: cannam@233: The above copyright notice and this permission notice shall be cannam@233: included in all copies or substantial portions of the Software. cannam@233: cannam@233: THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, cannam@233: EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF cannam@233: MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND cannam@233: NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR cannam@233: ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF cannam@233: CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION cannam@233: WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. cannam@233: cannam@233: Except as contained in this notice, the names of the Centre for cannam@233: Digital Music; Queen Mary, University of London; and Chris Cannam cannam@233: shall not be used in advertising or otherwise to promote the sale, cannam@233: use or other dealings in this Software without prior written cannam@233: authorization. cannam@233: */ cannam@233: cannam@233: #ifndef _VAMP_PLUGIN_CHANNEL_ADAPTER_H_ cannam@233: #define _VAMP_PLUGIN_CHANNEL_ADAPTER_H_ cannam@233: cannam@243: #include "hostguard.h" cannam@233: #include "PluginWrapper.h" cannam@233: cannam@233: namespace Vamp { cannam@233: cannam@233: namespace HostExt { cannam@233: cannam@233: /** cannam@233: * \class PluginChannelAdapter PluginChannelAdapter.h cannam@233: * cannam@233: * PluginChannelAdapter is a Vamp plugin adapter that implements a cannam@233: * policy for management of plugins that expect a different number of cannam@233: * input channels from the number actually available in the source cannam@233: * audio data. cannam@233: * cannam@233: * A host using PluginChannelAdapter may ignore the getMinChannelCount cannam@233: * and getMaxChannelCount reported by the plugin, and still expect the cannam@233: * plugin to run. cannam@233: * cannam@233: * PluginChannelAdapter implements the following policy: cannam@233: * cannam@233: * - If the plugin supports the provided number of channels directly, cannam@233: * PluginChannelAdapter will just run the plugin as normal. cannam@233: * cannam@233: * - If the plugin only supports exactly one channel but more than cannam@233: * one channel is provided, PluginChannelAdapter will use the mean of cannam@233: * the channels. This ensures that the resulting values remain cannam@233: * within the same magnitude range as expected for mono data. cannam@233: * cannam@233: * - If the plugin requires more than one channel but exactly one is cannam@233: * provided, the provided channel will be duplicated across all the cannam@233: * plugin input channels. cannam@233: * cannam@233: * If none of the above apply: cannam@233: * cannam@233: * - If the plugin requires more channels than are provided, the cannam@233: * minimum acceptable number of channels will be produced by adding cannam@233: * empty (zero valued) channels to those provided. cannam@233: * cannam@233: * - If the plugin requires fewer channels than are provided, the cannam@233: * maximum acceptable number of channels will be produced by cannam@233: * discarding the excess channels. cannam@233: * cannam@233: * Hosts requiring a different channel policy from the above will need cannam@233: * to implement it themselves, instead of using PluginChannelAdapter. cannam@233: * cannam@233: * Note that PluginChannelAdapter does not override the minimum and cannam@233: * maximum channel counts returned by the wrapped plugin. The host cannam@233: * will need to be aware that it is using a PluginChannelAdapter, and cannam@233: * be prepared to ignore these counts as necessary. (This contrasts cannam@233: * with the approach used in PluginInputDomainAdapter, which aims to cannam@233: * make the host completely unaware of which underlying input domain cannam@233: * is in fact in use.) cannam@233: * cannam@233: * (The rationale for this is that a host may wish to use the cannam@233: * PluginChannelAdapter but still discriminate in some way on the cannam@233: * basis of the number of channels actually supported. For example, a cannam@233: * simple stereo audio host may prefer to reject plugins that require cannam@233: * more than two channels on the grounds that doesn't actually cannam@233: * understand what they are for, rather than allow the channel adapter cannam@233: * to make a potentially meaningless channel conversion for them.) cannam@233: * cannam@233: * In every respect other than its management of channels, the cannam@233: * PluginChannelAdapter behaves identically to the plugin that it cannam@233: * wraps. The wrapped plugin will be deleted when the wrapper is cannam@233: * deleted. cannam@233: * cannam@233: * \note This class was introduced in version 1.1 of the Vamp plugin SDK. cannam@233: */ cannam@233: cannam@233: class PluginChannelAdapter : public PluginWrapper cannam@233: { cannam@233: public: cannam@233: PluginChannelAdapter(Plugin *plugin); // I take ownership of plugin cannam@233: virtual ~PluginChannelAdapter(); cannam@233: cannam@233: bool initialise(size_t channels, size_t stepSize, size_t blockSize); cannam@233: cannam@233: FeatureSet process(const float *const *inputBuffers, RealTime timestamp); cannam@233: cannam@233: /** cannam@233: * Call process(), providing interleaved audio data with the cannam@233: * number of channels passed to initialise(). The adapter will cannam@233: * de-interleave into temporary buffers as appropriate before cannam@233: * calling process(). cannam@233: * cannam@233: * \note This function was introduced in version 1.4 of the Vamp cannam@233: * plugin SDK. cannam@233: */ cannam@233: FeatureSet processInterleaved(const float *inputBuffer, RealTime timestamp); cannam@233: cannam@233: protected: cannam@233: class Impl; cannam@233: Impl *m_impl; cannam@233: }; cannam@233: cannam@233: } cannam@233: cannam@233: } cannam@233: cannam@233: #endif