comparison vamp-sdk/hostext/PluginInputDomainAdapter.h @ 64:9d3272c7db60

* Merge from host-factory-stuff branch: this adds several helper classes in
  the hostext directory that should make a host's life much easier.  This
  will become version 1.1 of the SDK, eventually.

+/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
+
+/*
+    Vamp
+
+    An API for audio analysis and feature extraction plugins.
+
+    Centre for Digital Music, Queen Mary, University of London.
+    Copyright 2006 Chris Cannam.
+  
+    Permission is hereby granted, free of charge, to any person
+    obtaining a copy of this software and associated documentation
+    files (the "Software"), to deal in the Software without
+    restriction, including without limitation the rights to use, copy,
+    modify, merge, publish, distribute, sublicense, and/or sell copies
+    of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be
+    included in all copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+    NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
+    ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
+    CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+    WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+    Except as contained in this notice, the names of the Centre for
+    Digital Music; Queen Mary, University of London; and Chris Cannam
+    shall not be used in advertising or otherwise to promote the sale,
+    use or other dealings in this Software without prior written
+    authorization.
+*/
+
+#ifndef _VAMP_PLUGIN_INPUT_DOMAIN_ADAPTER_H_
+#define _VAMP_PLUGIN_INPUT_DOMAIN_ADAPTER_H_
+
+#include "PluginWrapper.h"
+
+namespace Vamp {
+
+namespace HostExt {
+
+/**
+ * PluginInputDomainAdapter is a Vamp plugin adapter that converts
+ * time-domain input into frequency-domain input for plugins that need
+ * it.  This permits a host to use time- and frequency-domain plugins
+ * interchangeably without needing to handle the conversion itself.
+ *
+ * This adapter uses a basic Hanning windowed FFT that supports
+ * power-of-two block sizes only.  If a frequency domain plugin
+ * requests a non-power-of-two blocksize, the adapter will adjust it
+ * to a nearby power of two instead.  Thus, getPreferredBlockSize()
+ * will always return a power of two if the wrapped plugin is a
+ * frequency domain one.  If the plugin doesn't accept the adjusted
+ * power of two block size, initialise() will fail.
+ *
+ * The adapter provides no way for the host to discover whether the
+ * underlying plugin is actually a time or frequency domain plugin
+ * (except that if the preferred block size is not a power of two, it
+ * must be a time domain plugin).
+ *
+ * The FFT implementation is simple and self-contained, but unlikely
+ * to be the fastest available: a host can usually do better if it
+ * cares enough.
+ *
+ * In every respect other than its input domain handling, the
+ * PluginInputDomainAdapter behaves identically to the plugin that it
+ * wraps.  The wrapped plugin will be deleted when the wrapper is
+ * deleted.
+ */
+
+class PluginInputDomainAdapter : public PluginWrapper
+{
+public:
+    PluginInputDomainAdapter(Plugin *plugin); // I take ownership of plugin
+    virtual ~PluginInputDomainAdapter();
+    
+    bool initialise(size_t channels, size_t stepSize, size_t blockSize);
+
+    InputDomain getInputDomain() const;
+
+    size_t getPreferredStepSize() const;
+    size_t getPreferredBlockSize() const;
+
+    FeatureSet process(const float *const *inputBuffers, RealTime timestamp);
+
+protected:
+    size_t m_channels;
+    size_t m_blockSize;
+    float **m_freqbuf;
+    double *m_ri;
+    double *m_ro;
+    double *m_io;
+
+    void fft(unsigned int n, bool inverse,
+             double *ri, double *ii, double *ro, double *io);
+
+    size_t makeBlockSizeAcceptable(size_t) const;
+};
+
+}
+
+}
+
+#endif